WO2017138482A1 - Conductive particles, insulated coated conductive particles, anisotropic conductive adhesive, connected structure and method for producing conductive particles - Google Patents

Conductive particles, insulated coated conductive particles, anisotropic conductive adhesive, connected structure and method for producing conductive particles Download PDF

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Publication number
WO2017138482A1
WO2017138482A1 PCT/JP2017/004174 JP2017004174W WO2017138482A1 WO 2017138482 A1 WO2017138482 A1 WO 2017138482A1 JP 2017004174 W JP2017004174 W JP 2017004174W WO 2017138482 A1 WO2017138482 A1 WO 2017138482A1
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WIPO (PCT)
Prior art keywords
particles
conductive
conductive particles
layer
inorganic particles
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PCT/JP2017/004174
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French (fr)
Japanese (ja)
Inventor
芳則 江尻
邦彦 赤井
昌之 中川
渡辺　靖
正彦 野口
将平 山崎
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日立化成株式会社
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Application filed by 日立化成株式会社 filed Critical 日立化成株式会社
Priority to KR1020187025419A priority Critical patent/KR102649653B1/en
Priority to JP2017566930A priority patent/JP6737292B2/en
Priority to CN201780010477.XA priority patent/CN108604480B/en
Publication of WO2017138482A1 publication Critical patent/WO2017138482A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H01B5/16—Non-insulated conductors or conductive bodies characterised by their form comprising conductive material in insulating or poorly conductive material, e.g. conductive rubber
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R11/00—Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts
    • H01R11/01—Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts characterised by the form or arrangement of the conductive interconnection between the connecting locations

Definitions

  • the present invention relates to a conductive particle, an insulating coated conductive particle, an anisotropic conductive adhesive, a connection structure, and a method for manufacturing the conductive particle.
  • the method of mounting a liquid crystal driving IC on a glass panel for liquid crystal display can be roughly divided into two types: COG (Chip-on-Glass) mounting and COF (Chip-on-Flex) mounting.
  • COG mounting a liquid crystal driving IC is directly bonded onto a glass panel using an anisotropic conductive adhesive containing conductive particles.
  • COF mounting a liquid crystal driving IC is bonded to a flexible tape having metal wiring, and these are bonded to a glass panel using an anisotropic conductive adhesive containing conductive particles.
  • anisotropic as used herein means that conduction is achieved in the pressurizing direction and insulation is maintained in the non-pressurizing direction.
  • Conductive particles having a gold layer on the surface have been used as the conductive particles.
  • Conductive particles having a gold layer on the surface are advantageous in that they have a low electrical resistance value. Since gold is not easily oxidized, even when conductive particles having a gold layer on the surface are stored for a long period of time, an increase in the electrical resistance value of the conductive particles can be suppressed.
  • Patent Documents 1 to 3 disclose conductive particles having a low electric resistance value using only nickel without using a noble metal.
  • Patent Document 1 by utilizing the self-decomposition of a nickel plating solution in an electroless nickel plating method, a nickel microprojection and a nickel coating are simultaneously formed on non-conductive particles, and the surface is made conductive.
  • a method for producing conductive particles having protrusions is described.
  • Patent Document 2 conductive particles having conductive protrusions on the surface are obtained by attaching an electroconductive substance serving as a core substance to the surface of the base particle, and then performing electroless nickel plating on the base particle. A method of manufacturing is described.
  • Patent Document 3 a non-conductive substance serving as a core substance is adsorbed on the surface of the base particle by chemical bonding, and then electroless nickel plating is performed on the base particle, thereby forming a conductive protrusion on the surface.
  • a method for producing conductive particles is described.
  • connection structure using the anisotropic conductive adhesive containing the conductive particles described in Patent Documents 1 to 3 shows a sufficient connection resistance value at the initial connection stage. However, when these connection structures are stored under high temperature and high humidity, the connection resistance value may increase.
  • connection structure using the anisotropic conductive adhesive containing the conductive particles described in Patent Documents 1 to 3 a sufficient insulation resistance value is shown at the initial connection stage, but the connection structure is long under high temperature and high humidity.
  • the insulation resistance value may decrease after a migration test in which conduction is performed for a period.
  • One aspect of the present invention is to provide conductive particles capable of achieving both excellent conduction reliability and insulation reliability when used as conductive particles blended in an anisotropic conductive adhesive, and a method for producing the same. With the goal.
  • Another object of the present invention is to provide insulating coated conductive particles, anisotropic conductive adhesives, and connection structures using the conductive particles.
  • Conductive particles according to one embodiment of the present invention include resin particles coated with a cationic polymer, composite particles having non-conductive inorganic particles disposed on the surfaces of the resin particles, and a metal layer covering the composite particles.
  • the non-conductive inorganic particles are coated with a hydrophobizing agent.
  • the resin particles are coated with the cationic polymer, and the non-conductive inorganic particles are coated with the hydrophobic treatment agent.
  • the zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity.
  • an electrostatic force acts between the resin particles and the non-conductive inorganic particles, and the non-conductive inorganic particles are not easily dropped from the surface of the resin particles.
  • the hydrophobizing agent may be selected from the group consisting of a silazane hydrophobizing agent, a siloxane hydrophobizing agent, a silane hydrophobizing agent, and a titanate hydrophobizing agent.
  • the hydrophobizing agent may be selected from the group consisting of hexamethylene disilazane, polydimethylsiloxane, and N, N-dimethylaminotrimethylsilane.
  • the hydrophobicity of the non-conductive inorganic particles by methanol titration method may be 30% or more. In this case, a sufficient electrostatic force acts between the non-conductive inorganic particles and the resin particles.
  • Non-conductive inorganic particles may be adhered to resin particles by electrostatic force.
  • the difference in zeta potential between the resin particles and the non-conductive inorganic particles may be 30 mV or more at pH 1 or more and pH 11 or less.
  • the resin particles and the non-conductive inorganic particles are firmly bonded by electrostatic force. Therefore, it is possible to suitably suppress the nonconductive inorganic particles from dropping from the resin particles during the pretreatment step for forming the metal layer in the conductive particles, the metal layer forming step, and the like.
  • the cationic polymer may be selected from the group consisting of polyamine, polyimine, polyamide, polydiallyldimethylammonium chloride, polyvinylamine, polyvinylpyridine, polyvinylimidazole, and polyvinylpyrrolidone.
  • the cationic polymer may be polyethyleneimine.
  • the charge density of the cationic polymer is increased, it is possible to favorably suppress the non-conductive inorganic particles from falling off.
  • the average particle diameter of the non-conductive inorganic particles may be 25 nm or more and 120 nm or less.
  • the conductive particles can have a large number of dense protrusions, and the non-conductive inorganic particles are difficult to drop off from the resin particles.
  • the average particle diameter of the resin particles may be 1 ⁇ m or more and 10 ⁇ m or less.
  • the anisotropic conductive adhesive may vary depending on the shape (height) of the electrodes of the connection structure. It becomes difficult for the conductivity etc. of this to change.
  • the non-conductive inorganic particles may be selected from the group consisting of silica, zirconia, alumina, and diamond.
  • the metal layer may have a first layer containing nickel.
  • the hardness of the conductive particles can be increased. Thereby, even when the conductive particles are compressed, the first layer formed on the non-conductive inorganic particles and serving as a protruding portion is not easily crushed. Therefore, the conductive particles can obtain a low conduction resistance.
  • the metal layer may have a second layer provided on the first layer, and the second layer may contain a metal selected from the group consisting of noble metals and cobalt.
  • the conductive particles can obtain a lower conduction resistance.
  • An insulating coated conductive particle includes the conductive particle and an insulating coating portion that covers at least a part of the outer surface of the metal layer of the conductive particle.
  • the resin particles are coated with the cationic polymer, and the nonconductive inorganic particles are coated with the hydrophobizing agent.
  • the zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity.
  • an electrostatic force acts between the resin particles and the non-conductive inorganic particles, and the non-conductive inorganic particles are not easily dropped from the surface of the resin particles. For this reason, it becomes easy to control the number of non-conductive inorganic particles arranged on the surface of the resin particles, and good protrusions are formed on the composite particles.
  • connection structure using the anisotropic conductive adhesive containing conductive particles is stored under high temperature and high humidity, conduction reliability is improved.
  • the insulating coating portions provided on the outer surface of the metal layer make it difficult for the metal layers of the insulating coated conductive particles to come into contact with each other.
  • the insulating coating conductive particles are blended in the anisotropic conductive adhesive, the insulating coating conductive particles are difficult to conduct with each other, and the insulation reliability of the connection structure using the insulating coating conductive particles is also suitable. To improve. Therefore, excellent conduction reliability and insulation reliability can be achieved by blending the conductive particles with the anisotropic conductive adhesive.
  • a connection structure includes a first circuit member having a first circuit electrode, a second circuit member facing the first circuit member and having a second circuit electrode, and a first circuit member. And a connecting portion that is disposed between the second circuit members and contains the conductive particles, and the connecting portion is arranged in such a manner that the first circuit electrode and the second circuit electrode face each other.
  • the circuit member and the second circuit member are connected to each other, and the first circuit electrode and the second circuit electrode are electrically connected to each other through the deformed conductive particles.
  • connection reliability is improved by providing the connection part containing the conductive particles, even when the connection structure is stored under high temperature and high humidity.
  • the connection reliability is also preferably improved. Therefore, it is possible to provide a connection structure having both excellent conduction reliability and insulation reliability.
  • a connection structure includes a first circuit member having a first circuit electrode, a second circuit member facing the first circuit member and having a second circuit electrode, and a first circuit member. And a connecting portion that is disposed between the second circuit member and contains the insulating coating conductive particles, and the connecting portion is disposed in such a manner that the first circuit electrode and the second circuit electrode face each other.
  • the first circuit member and the second circuit member are connected to each other, and the first circuit electrode and the second circuit electrode are electrically connected to each other via the insulating coated conductive particles in a deformed state.
  • connection structure by providing the connection portion containing the insulating coating conductive particles, the conduction reliability is improved even when stored under high temperature and high humidity.
  • the number of non-conductive inorganic particles falling off from the resin particles in the connecting portion is reduced, it is difficult for abnormally grown protrusions to be generated on the composite particles.
  • the insulating coating portions provided on the outer surface of the metal layer make it difficult for the metal layers of the insulating coated conductive particles to come into contact with each other. Accordingly, it becomes difficult for the insulating coated conductive particles to conduct in the connection portion, and the insulation reliability is also preferably improved. Therefore, it is possible to provide a connection structure having both excellent conduction reliability and insulation reliability.
  • An anisotropic conductive adhesive according to another embodiment of the present invention includes the conductive particles and an adhesive in which the conductive particles are dispersed.
  • anisotropic conductive adhesive resin particles are coated with a cationic polymer, and non-conductive inorganic particles are coated with a hydrophobizing agent.
  • the zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity.
  • an electrostatic force acts between the resin particles and the non-conductive inorganic particles, and the non-conductive inorganic particles are not easily dropped from the surface of the resin particles. For this reason, it becomes easy to control the number of non-conductive inorganic particles arranged on the surface of the resin particles, and good protrusions are formed on the composite particles. Therefore, even when the connection structure using the anisotropic conductive adhesive is stored under high temperature and high humidity, conduction reliability is improved.
  • An anisotropic conductive adhesive according to another embodiment of the present invention includes the insulating coating conductive particles and an adhesive in which the insulating coating conductive particles are dispersed.
  • anisotropic conductive adhesive resin particles are coated with a cationic polymer, and non-conductive inorganic particles are coated with a hydrophobizing agent.
  • the zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity.
  • an electrostatic force acts between the resin particles and the non-conductive inorganic particles, and the non-conductive inorganic particles are not easily dropped from the surface of the resin particles. For this reason, it becomes easy to control the number of non-conductive inorganic particles arranged on the surface of the resin particles, and good protrusions are formed on the composite particles. Therefore, even when the connection structure using the anisotropic conductive adhesive is stored under high temperature and high humidity, conduction reliability is improved.
  • the insulating coating provided on the outer surface of the metal layer makes it difficult for the metal layers of the conductive particles to contact each other.
  • the metal foreign matter formed by coating the dropped non-conductive inorganic particles with a metal is unlikely to exist in the adhesive. Therefore, it becomes difficult for the conductive particles to conduct well, and the insulation reliability of the connection structure using the conductive particles is also preferably improved.
  • the adhesive may be in the form of a film.
  • a connection structure includes a first circuit member having a first circuit electrode, a second circuit member facing the first circuit member and having a second circuit electrode, and a first circuit member. And the anisotropic conductive adhesive for bonding the second circuit member, the first circuit electrode and the second circuit electrode are opposed to each other and electrically connected to each other by the anisotropic conductive adhesive Is done.
  • connection structure the first circuit member and the second circuit member are electrically connected to each other by the anisotropic conductive adhesive, thereby achieving both excellent conduction reliability and insulation reliability. it can.
  • the method for producing conductive particles according to another aspect of the present invention includes a first coating step of coating resin particles with a cationic polymer, and a second coating step of coating non-conductive inorganic particles with a hydrophobic treatment agent, A non-conductive inorganic particle is adhered to the surface of the resin particle by electrostatic force to form a composite particle, and a third coating step of coating the composite particle with a metal layer.
  • the resin particles are coated with the cationic polymer in the first coating step, and the non-conductive inorganic particles are coated with the hydrophobic treatment agent in the second coating step.
  • the zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity.
  • an electrostatic force acts between the resin particles and the non-conductive inorganic particles in the particle forming step, so even when the third coating step is performed, the non-conductive inorganic particles are formed from the surface of the resin particles. Particles are less likely to fall off.
  • the composite particles may be coated with a first layer containing nickel by electroless plating.
  • the composite particles covered with the first layer may be coated with a second layer containing a metal selected from the group consisting of noble metals and cobalt.
  • the conductive particles can obtain a lower conduction resistance.
  • the difference in zeta potential between the resin particles and the non-conductive inorganic particles may be 30 mV or more at pH 1 or more and pH 11 or less.
  • the resin particles and the non-conductive inorganic particles are firmly bonded by electrostatic force. Therefore, it can suppress suitably that a nonelectroconductive inorganic particle falls from the resin particle in the case of a 3rd coating process.
  • conductive particles capable of achieving both excellent conduction reliability and insulation reliability when used as conductive particles blended in an anisotropic conductive adhesive, and a method for producing the same. Is done. Moreover, according to one side of this invention, the insulation coating electrically-conductive particle, anisotropic conductive adhesive, and connection structure using the said electrically-conductive particle are provided.
  • FIG. 1 is a schematic cross-sectional view showing conductive particles according to the first embodiment.
  • FIG. 2 is a schematic enlarged cross-sectional view showing the conductive particles according to the first embodiment.
  • FIG. 3 is a schematic cross-sectional view showing conductive particles according to the second embodiment.
  • FIG. 4 is a schematic enlarged cross-sectional view showing conductive particles according to the second embodiment.
  • FIG. 5 is a schematic cross-sectional view showing insulating coated conductive particles according to the third embodiment.
  • FIG. 6 is a schematic cross-sectional view showing a connection structure according to the fifth embodiment.
  • FIG. 7 is a schematic cross-sectional view for explaining an example of the manufacturing method of the connection structure according to the fifth embodiment.
  • FIG. 1 is a schematic cross-sectional view showing conductive particles according to the first embodiment.
  • FIG. 2 is a schematic enlarged cross-sectional view showing the conductive particles according to the first embodiment.
  • FIG. 3 is a schematic cross-sectional view showing conductive particles according
  • FIG. 8 is an SEM image obtained by observing the particles obtained in step d in the production of the conductive particles of Example 1.
  • FIG. 9 is an SEM image obtained by observing the surface of the particles obtained in step d in the production of the conductive particles of Example 1.
  • FIG. 10 is an SEM image obtained by observing the particles obtained in step f in the production of the conductive particles of Example 1.
  • FIG. 11 is an SEM image obtained by observing the surface of the particles obtained in step f in the production of the conductive particles of Example 1.
  • FIG. 12 is a schematic diagram for explaining the trimming process.
  • FIG. 13 is a schematic diagram for explaining a method of producing a thin film slice for TEM measurement.
  • FIG. 14 is a schematic diagram for explaining an abnormal precipitation portion.
  • FIG. 15 is an SEM image obtained by observing particles obtained by ultrasonic dispersion after immersing resin particles having a palladium catalyst fixed thereon in Comparative Example 1.
  • FIG. 16 is an SEM image obtained by observing the conductive particles after forming the b layer of the first layer in Comparative Example 1.
  • FIG. 1 is a schematic cross-sectional view showing conductive particles according to the first embodiment.
  • a conductive particle 100 a illustrated in FIG. 1 includes resin particles 101 that form a core of conductive particles, composite particles 103 having non-conductive inorganic particles 102 disposed on the surfaces of the resin particles 101, and first particles that cover the composite particles 103. 1 layer 104.
  • a protrusion 109 is formed on the surface of the first layer 104, reflecting the shape of the non-conductive inorganic particles 102 bonded to the resin particles 101.
  • the resin particles 101 are coated with a cationic polymer described later.
  • the non-conductive inorganic particles 102 are coated with a hydrophobic treating agent described later.
  • the first layer 104 is a conductive layer containing at least a metal.
  • the first layer 104 may be a metal layer or an alloy layer.
  • the average particle diameter of the conductive particles 100a may be, for example, 1 ⁇ m or more, or 2 ⁇ m or more.
  • the average particle diameter of the conductive particles 100a may be, for example, 10 ⁇ m or less, or 5 ⁇ m or less. That is, the average particle diameter of the conductive particles 100a is, for example, 1 to 10 ⁇ m.
  • the average particle diameter of the conductive particles 100a is within the above range, for example, when a connection structure is manufactured using an anisotropic conductive adhesive containing the conductive particles 100a, the shape of the electrodes of the connection structure ( Due to the variation in (height), the conductivity of the anisotropic conductive adhesive is less likely to change.
  • the average particle diameter of the conductive particles 100a may be an average value obtained by measuring the particle diameter of 300 arbitrary conductive particles by observation using a scanning electron microscope (hereinafter referred to as “SEM”). Since the conductive particle 100a has the protrusion 109, the particle diameter of the conductive particle 100a is set to a diameter of a circle circumscribing the conductive particle 100a in an image taken by the SEM. In order to increase the accuracy and measure the average particle diameter of the conductive particles 100a, a commercially available apparatus such as a Coulter counter can be used. In this case, if the particle diameter of 50000 conductive particles is measured, the average particle diameter can be measured with high accuracy. For example, the average particle diameter of the conductive particles 100a may be measured by measuring 50,000 conductive particles using COULER MULTISIZER II (trade name, manufactured by Beckman Coulter, Inc.).
  • the resin particles 101 are made of an organic resin.
  • the organic resin include (meth) acrylic resins such as polymethyl methacrylate and polymethyl acrylate; polyolefin resins such as polyethylene and polypropylene; polyisobutylene resins; and polybutadiene resins.
  • the resin particles 101 particles obtained by crosslinking organic resins such as crosslinked (meth) acrylic particles and crosslinked polystyrene particles can also be used.
  • the resin particles may be composed of one kind of the organic resin or a combination of two or more kinds of the organic resin.
  • the organic resin is not limited to the above resin.
  • Resin particles 101 are spherical.
  • the average particle diameter of the resin particles 101 may be, for example, 1 ⁇ m or more and 10 ⁇ m or less.
  • the average particle diameter of the resin particles 101 may be, for example, 1 ⁇ m or more, or 2 ⁇ m or more.
  • the average particle diameter of the resin particles 101 may be, for example, 10 ⁇ m or less, or 5 ⁇ m or less.
  • the average particle diameter of the resin particles 101 is an average value obtained by measuring the particle diameter of 300 arbitrary resin particles by observation using an SEM.
  • the resin particles 101 are coated with a cationic polymer as a surface treatment.
  • the cationic polymer generally include a polymer compound having a functional group capable of being positively charged, such as polyamine.
  • the cationic polymer may be selected from the group consisting of, for example, polyamine, polyimine, polyamide, polydiallyldimethylammonium chloride, polyvinylamine, polyvinylpyridine, polyvinylimidazole, and polyvinylpyrrolidone.
  • Polyimine is preferable and polyethyleneimine is more preferable from the viewpoint of high charge density and strong binding force to negatively charged surfaces and materials.
  • the cationic polymer may be soluble in water or a mixed solution of water and an organic solvent. The molecular weight of the cationic polymer varies depending on the type of the cationic polymer used, but is, for example, about 500 to 200,000.
  • the coverage of the resin particles 101 with the non-conductive inorganic particles 102 can be controlled. Specifically, when the resin particles 101 are coated with a cationic polymer having a high charge density such as polyethyleneimine, the coverage of the nonconductive inorganic particles 102 (the ratio of the nonconductive inorganic particles 102 covering the resin particles 101) ) Tends to be high. On the other hand, when the resin particles 101 are coated with a cationic polymer having a low charge density, the coverage of the non-conductive inorganic particles 102 tends to be low.
  • the coverage of the nonconductive inorganic particles 102 tends to be high, and when the molecular weight of the cationic polymer is small, the coverage of the nonconductive inorganic particles 102 tends to be low.
  • Cationic polymers include alkali metal (Li, Na, K, Rb, Cs) ion, alkaline earth metal (Ca, Sr, Ba, Ra) ion, and halide ion (fluorine ion, chloride ion, bromine ion, iodine). Ions) may be substantially absent. In this case, electromigration and corrosion of the resin particles 101 coated with the cationic polymer are suppressed.
  • the resin particles 101 before being coated with the cationic polymer have a functional group selected from a hydroxyl group, a carboxyl group, an alkoxy group, a glycidyl group and an alkoxycarbonyl group on the surface. Thereby, the cationic polymer is easily adsorbed on the surface of the resin particle 101.
  • the zeta potential of the resin particles 101 coated with the cationic polymer is preferably positive (positive value) in any of water, an organic solvent, or a mixed solution containing water and an organic solvent.
  • the zeta potential of the resin particle 101 is measured by measuring the colloid vibration potential using, for example, a zeta potential probe (manufactured by Dispersion Technologies, trade name “DT300”), or by Zetasizer ZS (product of Malvern Instruments, trade name). ) To measure the electrophoretic mobility by laser Doppler velocity measurement.
  • a zeta potential probe manufactured by Dispersion Technologies, trade name “DT300”
  • Zetasizer ZS product of Malvern Instruments, trade name
  • the non-conductive inorganic particles 102 are firmly bonded to the resin particles 101 by electrostatic force.
  • the shape of the non-conductive inorganic particles 102 is not particularly limited, but may be an ellipsoid, a sphere, a hemisphere, a substantially ellipsoid, a substantially sphere, a substantially hemisphere, or the like. Among these, an ellipsoid or a sphere is preferable.
  • the coverage of the resin particles 101 with the non-conductive inorganic particles 102 is 20 to 80%. It only has to be. From the viewpoint of more reliably obtaining the insulating and conductive effects of the conductive particles 100a, the coverage may be 25% or more, 30% or more, or 70% or less. 60% or less.
  • the “coverage” means the ratio of the surface area of the non-conductive inorganic particles 102 in a concentric circle having a diameter that is 1 ⁇ 2 of the diameter of the resin particles 101 on the orthographic projection surface of the resin particles 101. .
  • the non-conductive inorganic particles 102 have a diameter of the conductive particles 100a. You may disperse
  • the non-conductive inorganic particles 102 may be arranged in a dotted manner in the direction (surface) perpendicular to the radial direction of the conductive particles 100a without contacting each other.
  • the number of non-conductive inorganic particles 102 in contact with each other may be, for example, 15 or less, 7 or less, or 0 in one conductive particle 100a. Zero means that the nonconductive inorganic particles 102 arranged on the surface of one conductive particle 100a are not in contact with each other, and all the nonconductive inorganic particles 102 are arranged in a scattered manner.
  • the material forming the non-conductive inorganic particles 102 may be harder than the material forming the first layer 104. Thereby, it becomes easy for the conductive particles to pierce the electrode or the like, and the conductivity is improved. That is, the idea is not to harden the entire conductive particles but to harden some of the conductive particles.
  • the Mohs hardness of the material forming the non-conductive inorganic particles 102 is larger than the Mohs hardness of the metal forming the first layer 104. Specifically, the Mohs hardness of the material forming the non-conductive inorganic particles 102 is 5 or more.
  • the difference between the Mohs hardness of the material forming the non-conductive inorganic particles 102 and the Mohs hardness of the metal forming the first layer 104 may be 1.0 or more.
  • the Mohs hardness of the non-conductive inorganic particles 102 may be higher than the Mohs hardness of all metals.
  • materials for forming the non-conductive inorganic particles 102 are silica (silicon dioxide (SiO 2 ), Mohs hardness 6-7), zirconia (Mohs hardness 8-9), alumina (Mohs hardness 9), and diamond. You may select from the group which consists of (Mohs hardness 10).
  • Hydroxyl groups (—OH) are formed on the surfaces of the non-conductive inorganic particles 102 and are coated with the hydrophobizing agent as described above.
  • the value of the Mohs hardness was referred to “Chemical Dictionary” (published by Kyoritsu Shuppan Co., Ltd.).
  • Silica particles may be used as the nonconductive inorganic particles 102.
  • the particle size of the silica particles is preferably controlled.
  • the type of silica particles is not particularly limited, and examples thereof include colloidal silica, fumed silica, and sol-gel silica.
  • Silica particles may be used alone or in combination of two or more. As silica particles, commercially available products or synthetic products may be used.
  • colloidal silica As a method for producing colloidal silica, known methods may be mentioned. Specifically, a method by hydrolysis of alkoxysilane described in pages 154 to 156 of “Science of Sol-Gel Process” (Sakuo Sakuo, published by Agne Sefu Co., Ltd.); JP-A-11-60232 A method of reacting methyl silicate and water by dropping methyl silicate or a mixture of methyl silicate and methanol into water, methanol and a mixed solvent composed of ammonia or ammonia and an ammonium salt, as described in 1.
  • Examples of commercially available water-dispersed colloidal silica include Snowtex, Snowtex UP (both manufactured by Nissan Chemical Industries, Ltd., trade name), Quatron PL series (manufactured by Fuso Chemical Industries, Ltd., trade name), and the like.
  • fumed silica As a method for producing fumed silica, a known method using a gas phase reaction in which silicon tetrachloride is vaporized and burned in an oxyhydrogen flame can be mentioned. Furthermore, fumed silica can be made into an aqueous dispersion by a known method. Examples of the method for preparing an aqueous dispersion include the methods described in JP-A No. 2004-43298, JP-A No. 2003-176123, JP-A No. 2002-309239, and the like. From the viewpoint of the insulation reliability of fumed silica, the concentration of alkali metal ions and alkaline earth metal ions in the aqueous dispersion is preferably 100 ppm or less. The Mohs hardness of fumed silica may be 5 or more, or 6 or more.
  • the hydrophobizing agent may contain at least one selected from the group consisting of the above (1) to (4).
  • the silazane-based hydrophobizing agent includes, for example, an organic silazane-based hydrophobizing agent.
  • organic silazane hydrophobizing agent include hexamethyldisilazane, trimethyldisilazane, tetramethyldisilazane, hexamethylcyclotrisilazane, heptamethyldisilazane, diphenyltetramethyldisilazane, divinyltetramethyldisilazane, and the like.
  • the organic silazane-based hydrophobizing agent may be other than the above.
  • siloxane-based hydrophobizing agent As siloxane-based hydrophobizing agents, polydimethylsiloxane, methylhydrogendisiloxane, dimethyldisiloxane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3 -Diphenyltetramethyldisiloxane, methylhydrogenpolysiloxane, dimethylpolysiloxane, amino-modified siloxane and the like.
  • the siloxane-based hydrophobizing agent may be other than the above.
  • silane-based hydrophobizing agent As silane-based hydrophobizing agents, N, N-dimethylaminotrimethylsilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylpropoxysilane, phenyldimethylmethoxysilane, chloropropyldimethylmethoxysilane, Dimethyldimethoxysilane, methyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, ethyltrimethoxysilane, dimethyldiethoxysilane, propyltriethoxysilane, n-butyltrimethoxysilane, n-hexyl Trimethoxysilane, n-octyltriethoxysilane, n-octylmethyldiethoxysilane, n-octa
  • Titanate-based hydrophobizing agents include KRTTS, KR46B, KR55, KR41B, KR38S, KR138S, KR238S, 338X, KR44, and KR9SA (all manufactured by Ajinomoto Fine Techno Co., Ltd., trade names) ) And the like.
  • the hydrophobizing agent may contain at least one selected from the group consisting of hexamethylene disilazane, polydimethylsiloxane, and N, N-dimethylaminotrimethylsilane.
  • the hydrophobizing agent may contain at least one selected from the group consisting of hexamethylene disilazane, polydimethylsiloxane, and N, N-dimethylaminotrimethylsilane.
  • the resin particles 101 and the non-conductive inorganic particles 102 are firmly bonded by electrostatic force.
  • the difference between the zeta potential of the non-conductive inorganic particles 102 and the zeta potential of the resin particles 101 may be 30 mV or more or 50 mV or more at pH 1 or more and pH 11 or less.
  • the zeta potential of the hydrophobic non-conductive inorganic particles 102 is preferably negative (negative value) in any of water, an organic solvent, and a mixed solution containing water and an organic solvent.
  • the zeta potential of the non-conductive inorganic particles 102 can be determined by measuring the colloid vibration potential using a zeta potential probe (manufactured by Dispersion Technologies, trade name “DT300”), or by Zetasizer ZS (Malvern Instruments, Inc.). It can be measured by measuring the electrophoretic mobility by laser Doppler velocity measurement using a trade name).
  • a zeta potential probe manufactured by Dispersion Technologies, trade name “DT300”
  • Zetasizer ZS Malvern Instruments, Inc.
  • the reason why the resin particles 101 coated with the cationic polymer and the non-conductive inorganic particles 102 coated with the hydrophobizing agent are firmly bonded not by chemical bonding force but by electrostatic force will be discussed.
  • hydrophobization treatment is performed with hexamethylene disilazane on silica particles to which a hydroxyl group is added as shown in the following chemical formula 1.
  • the silica particles are coated with methyl groups. Since the silica particles are coated with methyl groups, the non-conductive inorganic particles 102 are resin particles even though there is no chemical bond between the cationic polymer coated on the surface of the resin particles 101 and the silica particles.
  • the zeta potential of the non-conductive inorganic particle 102 coated with the hydrophobizing agent with hexamethylene disilazane is the highest among the non-conductive inorganic particles described above. It showed a negative potential.
  • the potential difference between the non-conductive inorganic particles 102 and the cationic polymer was maximized.
  • the electrostatic force generated by the difference in zeta potential that is, the potential difference between the resin particles 101 and the non-conductive inorganic particles 102 is increased. This is considered to be an important factor that affects the adhesion.
  • the hydrophobicity of the non-conductive inorganic particles 102 is not inhibited, the zeta potential of the non-conductive inorganic particles 102 is maintained on the negative side, and the resin particles 101 and the non-conductive inorganic particles 102 May be at least one selected from the group consisting of an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, and a nitrile group.
  • a treating agent that has at least one selected from the group consisting of an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, and a nitrile group and that does not inhibit the hydrophobic effect is separately provided. May be added.
  • the hydrophobizing agent has at least one selected from the group consisting of an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, and a nitrile group, and an amino group, a carboxylic acid group, and a hydroxyl group.
  • the adsorption of the palladium catalyst on the surface of the non-conductive inorganic particles 102 can be promoted.
  • the first layer 104 can be uniformly formed on the surface of the composite particle 103 via the palladium catalyst.
  • the average particle diameter of the nonconductive inorganic particles 102 is, for example, about 1/300 to 1/10 of the average particle diameter of the resin particles 101.
  • the average particle diameter of the non-conductive inorganic particles 102 is 1/300 or more of the average particle diameter of the resin particles 101, a sufficiently high protrusion 109 is obtained when the composite particles 103 are covered with the first layer 104. It is easy to be done.
  • the average particle diameter of the non-conductive inorganic particles 102 is 1/10 or less of the average particle diameter of the resin particles 101, the non-conductive inorganic particles 102 tend not to drop off from the resin particles 101.
  • the average particle diameter of the non-conductive inorganic particles 102 is equal to the average particle diameter of the resin particles 101. It is preferably 1/200 to 1/10, more preferably about 1/120 to 1/25. As described above, when the average particle diameter of the non-conductive inorganic particles 102 is within the above range, the conductive particles 100 a can have a large number of dense protrusions 109, and the non-conductive inorganic particles 102 are separated from the resin particles 101. It becomes difficult to drop off.
  • the preferable average particle diameter range of the non-conductive inorganic particles 102 is, for example, 25 to 120 nm when the average particle diameter of the resin particles 101 is 3 ⁇ m. Further, for example, the average particle diameter of the resin particles 101 is preferably 33 to 160 nm when it is 4 ⁇ m, preferably 42 to 200 nm when it is 5 ⁇ m, and 83 to 400 nm when it is 10 ⁇ m. It is preferable.
  • the non-conductive inorganic particles 102 for example, the case where the average particle diameter of the resin particles 101 is 3 ⁇ m is shown below as an example.
  • the protrusions 109 of the first layer 104 are likely to have an appropriate size. , Tend to lower resistance. It has been found that the zeta potential of the non-conductive inorganic particles 102 varies depending on the particle size, and the zeta potential shifts more negatively as the particle size decreases.
  • the non-conductive inorganic particles 102 when the average particle size of the non-conductive inorganic particles 102 is 120 nm or less (or 1/25 or less of the average particle size of the resin particles 101), the non-conductive inorganic particles 102 and the resin particles 101 The potential difference is sufficient, and the non-conductive inorganic particles 102 are less likely to drop off when the first layer 104 is formed. As a result, the number of protrusions 109 becomes sufficient, and the resistance tends to be reduced. In some cases, the metal of the first layer 104 covers the aggregated pieces of the non-conductive inorganic particles 102 that have fallen, and metal foreign matter may be generated.
  • the metal foreign matter may reattach to the resin particles 101, and an excessively long protrusion (for example, a protrusion having a length exceeding 500 nm) may be formed as an abnormal precipitation portion. In this case, the insulation reliability of the conductive particles 100a may be reduced. Furthermore, the metal foreign matter itself may cause a decrease in insulation reliability. Therefore, it is preferable to prevent the non-conductive inorganic particles 102 from dropping from the resin particles 101.
  • the average particle diameter of the non-conductive inorganic particles 102 may be 30 to 110 nm or 35 to 100 nm.
  • the particle size of the non-conductive inorganic particles 102 is measured by a specific surface area conversion method by the BET method or a small-angle X-ray scattering method.
  • the diameter of the non-conductive inorganic particles 102 means the diameter of a perfect circle having the same area as that of the non-conductive inorganic particles 102 on the orthographic projection surface of the non-conductive inorganic particles 102. Specifically, an image obtained by observing non-conductive inorganic particles with a SEM at a magnification of 100,000 is analyzed to define the outline of the non-conductive inorganic particles. Then, the area of any non-conductive inorganic particles is calculated, and the diameter of the non-conductive inorganic particles 102 is obtained from the area.
  • the “average particle diameter of the non-conductive inorganic particles 102” is an average particle calculated from the diameter of a perfect circle having the same area as that of the non-conductive inorganic particles 102 on the orthographic projection surface of the non-conductive inorganic particles 102. Means diameter. Specifically, an image obtained by observing non-conductive inorganic particles with a SEM at a magnification of 100,000 is analyzed to define the outline of the non-conductive inorganic particles. And the area of 500 arbitrary nonelectroconductive inorganic particles is calculated, respectively, and the average particle diameter calculated from the diameter when the area is converted into a circle is defined as the average particle diameter of the nonconductive inorganic particles 102.
  • the degree of hydrophobicity of the non-conductive inorganic particles 102 by the methanol titration method is, for example, 30% or more.
  • the nonconductive inorganic particles 102 can be firmly bonded to the resin particles 101 by electrostatic force.
  • the degree of hydrophobicity may be 50% or more, or 60% or more. The higher the degree of hydrophobicity, the more the zeta potential of the nonconductive inorganic particles 102 shifts to the negative side, and the nonconductive inorganic particles 102 can be firmly bonded to the resin particles 101 by electrostatic force.
  • Methanol titration method is a method for measuring the degree of hydrophobicity of powder using methanol. For example, first, 0.2 g of a powder whose hydrophobicity is to be measured is suspended on a 50 ml water surface. Next, methanol is gradually added to the water while gently stirring the water. For example, methanol is dropped using a burette. Next, the amount of methanol used when the powder on the water surface is all immersed in water is measured. Then, the percentage of the methanol volume with respect to the total volume of water and methanol is calculated, and this value is calculated as the degree of hydrophobicity of the powder.
  • Adhesion of the non-conductive inorganic particles 102 to the resin particles 101 can be performed using an organic solvent or a mixed solution of water and a water-soluble organic solvent.
  • water-soluble organic solvents examples include methanol, ethanol, propanol, acetone, dimethylformamide, and acetonitrile.
  • the potential difference between the resin particles 101 and the non-conductive inorganic particles 102 tends to be larger than when a mixed solution of the organic solvent and water is used. Therefore, when only the organic solvent is used, the non-conductive inorganic particles 102 tend to adhere firmly to the resin particles 101 with a strong electrostatic force. As a result, it is difficult for the non-conductive inorganic particles 102 to fall off the resin particles 101 when the first layer 104 is formed.
  • the first layer 104 is a conductive layer containing nickel as a main component.
  • the thickness of the first layer 104 is, for example, 40 nm to 200 nm.
  • the thickness of the first layer 104 is within the above range, cracking of the first layer 104 can be suppressed even when the conductive particles 100a are compressed.
  • the surface of the composite particle 103 can be sufficiently covered with the first layer 104.
  • the non-conductive inorganic particles 102 can be fixed to the resin particles 101, and the non-conductive inorganic particles 102 can be prevented from falling off.
  • the thickness of the first layer 104 may be 60 nm or more.
  • the thickness of the first layer 104 may be 150 nm or less, or 120 nm or less.
  • the first layer 104 may have a single layer structure or a stacked structure. In the present embodiment, the first layer 104 has a two-layer structure.
  • the thickness of the first layer 104 is calculated using a photograph taken with a transmission electron microscope (hereinafter referred to as “TEM”).
  • TEM transmission electron microscope
  • a cross section of the conductive particle 100a is cut out by an ultramicrotome method so as to pass near the center of the conductive particle 100a.
  • the cut section is observed at a magnification of 250,000 times using a TEM to obtain an image.
  • the thickness of the first layer 104 can be calculated from the cross-sectional area of the first layer 104 (FIG. 2) estimated from the obtained image.
  • the thickness of the first layer 104 is an average value of the thickness of 10 conductive particles.
  • the first layer 104 may contain at least one selected from the group consisting of phosphorus and boron in addition to the metal whose main component is nickel. Accordingly, the hardness of the first layer 104 containing nickel can be increased, and the conduction resistance when the conductive particles are compressed can be easily kept low.
  • the first layer 104 may contain a eutectoid metal together with phosphorus or boron.
  • the metal contained in the first layer 104 is, for example, cobalt, copper, zinc, iron, manganese, chromium, vanadium, molybdenum, palladium, tin, tungsten, and rhenium.
  • the first layer 104 can increase the hardness of the first layer 104 by containing nickel and the above metal.
  • the metal may include tungsten having a high hardness.
  • Examples of the constituent material of the first layer 104 include a combination of nickel (Ni) and phosphorus (P), a combination of nickel (Ni) and boron (B), nickel (Ni), tungsten (W), and boron (B). And a combination of nickel (Ni) and palladium (Pd).
  • a phosphorus-containing compound such as sodium hypophosphite may be used as a reducing agent.
  • phosphorus can be co-deposited, and the first layer 104 containing a nickel-phosphorus alloy can be formed.
  • the reducing agent for example, boron-containing compounds such as dimethylamine borane, sodium borohydride, potassium borohydride and the like may be used.
  • boron can be co-deposited, and the first layer 104 containing a nickel-boron alloy can be formed.
  • the hardness of the nickel-boron alloy is higher than that of the nickel-phosphorus alloy. Therefore, when a boron-containing compound is used as the reducing agent, the protrusions 109 formed on the top of the non-conductive inorganic particles 102 can be satisfactorily suppressed even when the conductive particles 100a are compressed.
  • the first layer 104 may have a concentration gradient in which the nickel concentration (content) increases as the distance from the surface of the composite particle 103 increases. With such a configuration, a low conduction resistance can be maintained even when the conductive particles 100a are compressed.
  • This concentration gradient may be continuous or discontinuous.
  • the concentration gradient of nickel is discontinuous, a plurality of layers having different nickel contents may be provided as the first layer 104 on the surface of the composite particle 103. In this case, the nickel concentration of the layer provided on the side far from the composite particle 103 is increased.
  • the nickel content in the first layer 104 increases as the surface approaches the surface in the thickness direction of the first layer 104.
  • the nickel content in the surface layer of the first layer 104 is, for example, 99 mass% to 97 mass%.
  • the thickness of the surface side layer is, for example, 5 to 60 nm.
  • the thickness of the layer may be 10 to 50 nm or 15 to 40 nm.
  • the connection resistance value of the first layer 104 tends to be low.
  • the thickness of the surface layer is 60 nm or less, the monodispersion rate of the conductive particles 100a tends to be further improved.
  • the first layer 104 when the nickel content in the surface layer of the first layer 104 is 99 mass% to 97 mass% and the thickness of the surface layer is 5 to 60 nm, the first layer 104 It becomes easier to lower the resistance. In addition, aggregation of the conductive particles 100a is further suppressed, and high insulation reliability is easily obtained.
  • a layer having a nickel content of 97% by mass or less may be formed on the composite particle 103 side.
  • the nickel content of the layer on the composite particle 103 side may be 95% by mass or less, or 94% by mass or less.
  • the thickness of the layer on the composite particle 103 side may be 20 nm or more, 40 nm or more, or 50 nm or more.
  • the conductive particles 100a are not easily affected by magnetism, and aggregation of the conductive particles 100a tends to be suppressed. is there.
  • the kind of element and the content of the element in the first layer 104 can be measured by, for example, cutting out a cross section of the conductive particle by an ultramicrotome method and then performing component analysis by EDX attached to the TEM.
  • the first layer 104 is formed by electroless nickel plating.
  • the electroless nickel plating solution contains a water-soluble nickel compound.
  • the electroless nickel plating solution may further contain at least one compound selected from the group consisting of a stabilizer (for example, bismuth nitrate), a complexing agent, a reducing agent, a pH adjusting agent, and a surfactant.
  • water-soluble nickel compound water-soluble nickel inorganic salts such as nickel sulfate, nickel chloride and nickel hypophosphite; water-soluble nickel organic salts such as nickel acetate and nickel malate are used.
  • a water-soluble nickel compound can be used individually by 1 type or in combination of 2 or more types.
  • the concentration of the water-soluble nickel compound in the electroless nickel plating solution is preferably 0.001 to 1 mol / L, and more preferably 0.01 to 0.3 mol / L.
  • concentration of the water-soluble nickel compound is within the above range, it is possible to sufficiently obtain the deposition rate of the plating film, and to suppress the viscosity of the plating solution from becoming too high, thereby improving the uniformity of nickel deposition. Can do.
  • any complexing agent may be used as long as it functions as a complexing agent.
  • ethylenediaminetetraacetic acid; sodium salt of ethylenediaminetetraacetic acid (for example, 1-, 2-, 3- and 4-sodium salts) Ethylenediaminetriacetic acid; nitrotetraacetic acid, alkali salts thereof; glyconic acid, tartaric acid, gluconate, citric acid, gluconic acid, succinic acid, pyrophosphoric acid, glycolic acid, lactic acid, malic acid, malonic acid, alkali salts thereof (for example, sodium Salt); triethanolamine glucono ( ⁇ ) -lactone and the like.
  • a complexing agent can be used individually by 1 type or in combination of 2 or more types.
  • the concentration of the complexing agent in the electroless nickel plating solution is usually preferably 0.001 to 2 mol / L, and more preferably 0.002 to 1 mol / L.
  • concentration of the complexing agent is within the above range, it is possible to obtain a sufficient deposition rate of the plating film while suppressing precipitation of nickel hydroxide in the plating solution and decomposition of the plating solution, and the viscosity of the plating solution. Can be prevented from becoming too high, and the uniformity of nickel deposition can be improved.
  • the concentration of the complexing agent may vary depending on the type.
  • reducing agent a known reducing agent used for an electroless nickel plating solution can be used.
  • the reducing agent include hypophosphite compounds such as sodium hypophosphite and potassium hypophosphite; borohydride compounds such as sodium borohydride, potassium borohydride and dimethylamine borane; hydrazines and the like. .
  • the concentration of the reducing agent in the electroless nickel plating solution is usually preferably 0.001 to 1 mol / L, and more preferably 0.002 to 0.5 mol / L.
  • concentration of the reducing agent is within the above range, decomposition of the plating solution can be suppressed while sufficiently obtaining a nickel ion reduction rate in the plating solution.
  • concentration of the reducing agent may vary depending on the type of the reducing agent.
  • Examples of the pH adjuster include an acidic pH adjuster and an alkaline pH adjuster.
  • Acidic pH adjusters include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, formic acid, cupric chloride, iron compounds such as ferric sulfate, alkali metal chlorides, ammonium persulfate, and aqueous solutions containing one or more of these.
  • An aqueous solution containing acidic hexavalent chromium such as chromic acid, chromic acid-sulfuric acid, chromic acid-hydrofluoric acid, dichromic acid, dichromic acid-borofluoric acid, and the like.
  • alkaline pH adjusters examples include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and sodium carbonate; alkaline earth metal hydroxides; amino groups such as ethylenediamine, methylamine, and 2-aminoethanol. Compounds containing; solutions containing one or more of these may be mentioned.
  • a cationic surfactant an anionic surfactant, an amphoteric surfactant, a nonionic surfactant, a mixture thereof, or the like can be used.
  • the composite particles 103 may be preliminarily treated with a palladium catalyst.
  • the palladium catalyst treatment can be performed by a known method. The method is not particularly limited, and examples thereof include a catalytic treatment method using a catalytic treatment liquid called an alkali seeder or an acidic seeder.
  • Examples of the catalyst treatment method using an alkali seeder include the following methods. First, by immersing resin particles in a solution containing palladium ions coordinated with 2-aminopyridine, the palladium ions are adsorbed on the surface of the resin particles. After washing with water, the resin particles adsorbed with palladium ions are dispersed in a solution containing a reducing agent such as sodium hypophosphite, sodium borohydride, dimethylamine borane, hydrazine, formalin and the like to perform a reduction treatment. Thus, palladium ions adsorbed on the surface of the resin particles are reduced to metallic palladium.
  • a reducing agent such as sodium hypophosphite, sodium borohydride, dimethylamine borane, hydrazine, formalin and the like
  • Examples of the catalytic treatment method using an acidic seeder include the following methods. First, the resin particles are dispersed in a stannous chloride solution and subjected to a sensitization treatment in which tin ions are adsorbed on the surface of the resin particles, and then washed with water. Next, an activation treatment is performed in which the solution is dispersed in a solution containing palladium chloride to trap palladium ions on the surface of the resin particles. After washing with water, reduction treatment is performed by dispersing in a solution containing a reducing agent such as sodium hypophosphite, sodium borohydride, dimethylamine borane, hydrazine, formalin and the like. Thus, palladium ions adsorbed on the surface of the resin particles are reduced to metallic palladium.
  • a reducing agent such as sodium hypophosphite, sodium borohydride, dimethylamine borane, hydrazine, formalin and the like.
  • the acidic seeder is preferable from the viewpoint of the pH of the solution.
  • the zeta potential of the resin particle 101 itself shifts to a plus as the pH is lower it is preferable to use an acidic seeder.
  • the zeta potential of the non-conductive inorganic particles 102 shifts to negative as the pH increases, it is preferable to use an alkali seeder.
  • the difference in zeta potential between the resin particles 101 and the non-conductive inorganic particles 102 the difference in zeta potential tends to increase as the pH decreases.
  • an acidic seeder the non-conductive inorganic particles 102 tend to be maintained firmly bonded to the resin particles 101 by electrostatic force.
  • the hydrophobizing agent preferably has at least one selected from the group consisting of an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, and a nitrile group.
  • the H + of the carboxylic acid group and the hydroxyl group is dissociated at a pH of 7 or higher, and the zeta potential of the non-conductive inorganic particles 102 is shifted to the minus side.
  • the zeta potential of the resin particles 101 also varies depending on the pH, it is preferable to select the type of seeder so that the difference in zeta potential between the resin particles 101 and the non-conductive inorganic particles 102 can be kept large.
  • palladium ions are adsorbed on the surface, washed with water, and further dispersed in a solution containing a reducing agent.
  • palladium precipitation nuclei having an atomic level can be formed by reducing palladium ions adsorbed on the surface of the composite particle 103.
  • the area of the protrusion 109 in the conductive particle 100a is the area of the protrusion 109 in a concentric circle having a diameter that is 1 ⁇ 2 of the diameter of the conductive particle 100a on the orthographic projection surface of the conductive particle 100a, or between adjacent protrusions 109. It means the area of the outline of each protrusion 109 delimited by a valley.
  • the diameter (outer diameter) of the protrusion 109 is calculated for the protrusion 109 existing in a concentric circle having a diameter 1 ⁇ 2 of the diameter of the conductive particle 100a on the orthographic projection surface of the conductive particle 100a, and is the same as the area of the protrusion 109.
  • the diameter of a perfect circle having an area of Specifically, an image obtained by observing the conductive particles 100a by 30,000 times with an SEM is analyzed, and the contour of the protrusion 109 is defined to obtain the area of each protrusion. Then, the diameter is calculated from this area.
  • the ratio (coverage) of the area of the protrusion 109 is 1 / of the diameter of the conductive particle 100a with the total area of concentric circles having a diameter that is 1/2 the diameter of the conductive particle 100a on the orthographic projection surface of the conductive particle 100a.
  • the sum of the areas of the protrusions 109 in the concentric circles having a diameter of 2 can be expressed as a 100-percent fraction calculated as a numerator.
  • the area ratio (coverage) of the protrusions 109 may be 50% or more, 65% or more, or 80% or more. When the coverage by the protrusions 109 is within the above range, even when the conductive particles 100a are placed under high humidity, the conduction resistance is unlikely to increase.
  • the optimal diameter (outer diameter) of the protrusion 109 and the optimal ratio of the coverage with the protrusion 109 differ depending on the diameter of the resin particles 101 and the non-conductive inorganic particles 102. Regardless of which non-conductive inorganic particles 102 are used, the coverage of the resin particles 101 by the non-conductive inorganic particles 102 can be set to 20 to 80%, so that the coverage by the protrusions 109 can be 50% or more. It is.
  • the ratio of the protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a is less than 80% of the total number of protrusions.
  • the ratio of protrusions 109 having a diameter of 100 nm or more and less than 200 nm may be 20 to 80% of the total number of protrusions, and the ratio of protrusions 109 having a diameter of 200 nm or more is less than 20% of the total number of protrusions. Also good.
  • the ratio of protrusions 109 having a diameter of less than 100 nm may be less than 70% of the total number of protrusions, and the ratio of protrusions 109 having a diameter of 100 nm or more and less than 200 nm is 30% of the total number of protrusions.
  • the ratio of protrusions 109 having a diameter of 200 nm or more may be less than 15% with respect to the total number of protrusions.
  • the number of protrusions 109 having a diameter (outer diameter) of less than 100 nm may be 50 or more, or 80 or more.
  • the number of protrusions 109 having a diameter of 100 nm or more and less than 200 nm per conductive particle 100a may be 30 or more, or 50 or more.
  • the number of protrusions 109 having a diameter of 200 nm or more and 350 nm or less per conductive particle 100a may be 15 or less, 2 to 13 or 2 to 10 or less.
  • the ratio of the protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a is less than 70% of the total number of protrusions.
  • the ratio of the protrusions 109 having a diameter of 100 nm or more and less than 200 nm may be 20 to 80% of the total number of protrusions, and the ratio of the protrusions 109 having a diameter of 200 nm or more is less than 20% of the total number of protrusions. There may be.
  • the ratio of protrusions 109 having a diameter of less than 100 nm may be less than 60% of the total number of protrusions, and the ratio of protrusions 109 having a diameter of 100 nm to less than 200 nm may be 30% of the total number of protrusions.
  • the ratio of protrusions 109 having a diameter of 200 nm or more may be less than 15% with respect to the total number of protrusions.
  • the number of protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a may be 30 or more, or 50 or more.
  • the number of protrusions 109 having a diameter of 100 nm or more and less than 200 nm per conductive particle 100a may be 30 or more, or 50 or more.
  • the number of protrusions 109 having a diameter of 200 nm or more and 350 nm or less per conductive particle 100a may be 15 or less, 2 to 13 or 2 to 10 or less.
  • the ratio of the protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a is less than 70% of the total number of protrusions.
  • the ratio of the protrusions 109 having a diameter of 100 nm or more and less than 200 nm may be 20 to 90% of the total number of protrusions, and the ratio of the protrusions 109 having a diameter of 200 nm or more may be less than 70% of the total number of protrusions. There may be.
  • the ratio of the protrusions 109 having a diameter of less than 100 nm may be less than 60% with respect to the total number of protrusions, and the ratio of the protrusions 109 having a diameter of 100 nm to less than 200 nm is the total number of protrusions.
  • the ratio of the protrusions 109 having a diameter of 200 nm or more may be less than 50% with respect to the total number of protrusions.
  • the number of protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a may be 30 or more, or 50 or more.
  • the number of protrusions 109 having a diameter of 100 nm or more and less than 200 nm per conductive particle 100a may be 30 or more, or 50 or more.
  • the number of protrusions 109 having a diameter of 200 nm or more and 350 nm or less per conductive particle 100a may be 15 or less, 2 to 13 or 2 to 10 or less.
  • the conductivity is sufficiently low. Resistance can be obtained.
  • the monodispersion rate of the conductive particles 100a may be 96.0% or more, or 98.0% or more. When the monodispersion rate of the conductive particles 100a is within the above range, for example, high insulation reliability can be obtained after a moisture absorption test.
  • the monodispersion rate of the conductive particles 100a can be measured by, for example, COULER MULTISIZER II (trade name, manufactured by Beckman Coulter, Inc.) using 50,000 conductive particles.
  • the resin particles 101 are coated with a cationic polymer (first coating step).
  • resin particles 101 having a hydroxyl group or the like on the surface thereof are dispersed in a cationic polymer solution to coat the resin particles 101 with a cationic polymer.
  • the surface of the non-conductive inorganic particles 102 is coated with a hydrophobizing agent (second coating step).
  • the non-conductive inorganic particles 102 are coated with the hydrophobizing agent in water, an organic solvent, a mixed solution of water and a water-soluble organic solvent, or in a gas phase.
  • water-soluble organic solvents examples include methanol, ethanol, propanol, acetone, dimethylformamide, and acetonitrile.
  • Non-conductive inorganic particles coated with a hydrophobic treatment agent in advance may be purchased and used as the non-conductive inorganic particles 102.
  • non-conductive inorganic particles 102 are bonded to the surface of the resin particles 101 to form composite particles 103 (particle formation step).
  • Adhesion of the non-conductive inorganic particles 102 to the resin particles 101 is performed using, for example, an organic solvent or a mixed solution of water and a water-soluble organic solvent. It is preferable to adhere the nonconductive inorganic particles 102 to the resin particles 101 using only an organic solvent.
  • the non-conductive inorganic particles 102 and the resin are better when only the organic solvent is used than when the organic solvent containing water is used. The difference in zeta potential with the particle 101 increases.
  • the non-conductive inorganic particles 102 When a stronger electrostatic force acts between the non-conductive inorganic particles 102 and the resin particles 101, the non-conductive inorganic particles 102 can be firmly bonded to the resin particles 101. As a result, in the pretreatment process for performing electroless nickel plating and the electroless nickel plating process, the nonconductive inorganic particles 102 are difficult to drop off.
  • the composite particles 103 are coated with a metal layer by electroless plating (third coating step).
  • the first layer 104 containing nickel is used as a metal layer, and the entire surface of the composite particles 103 (that is, the entire surface where the resin particles 101 and the nonconductive inorganic particles 102 are exposed) is formed by the first layer 104. Cover.
  • the composite particles 103 may be subjected to a palladium catalyst treatment.
  • the palladium catalyst treatment can be performed by a known method, for example, by a catalyst treatment method using a catalyst treatment solution called an alkali seeder or an acid seeder described above. Even if the non-conductive inorganic particles 102 are arranged on the surface of the resin particles 101 in advance, the zeta potential of the resin particles 101 and the non-conductive inorganic particles 102 changes due to the influence of the surrounding pH.
  • the pH of the catalyzed solution becomes about 1.
  • the absolute value of the difference between the measured value of the zeta potential of the resin particles 101 and the measured value of the zeta potential of the non-conductive inorganic particles 102 is 50 mV or more.
  • the non-conductive inorganic particles 102 coated with the hydrophobizing agent are difficult to drop off.
  • the pH of the catalyzed treatment liquid becomes 10-11.
  • the absolute value of the difference between the measured value of the zeta potential of the resin particles 101 and the measured value of the zeta potential of the non-conductive inorganic particles 102 is about 30 to 50 mV. For this reason, in the pretreatment step, the non-conductive inorganic particles 102 are easily dropped from the resin particles 101.
  • a non-conductive substance serving as a core substance is adsorbed on the surface of resin particles by chemical bonding to form composite particles.
  • the pretreatment process for performing electroless nickel plating or the electroless nickel plating process is performed in order to coat the composite particles with the metal layer, the non-conductive substance is dropped from the resin particles. For this reason, it is difficult to control the number, size, and shape of the protrusions in the composite particles, and the resistance value of an adhesive using these conductive particles tends to increase.
  • the nonconductive material on which nickel is deposited falls during the electroless nickel plating step, it becomes a source of metal foreign matter. When the metal foreign matter reattaches to the composite particles, abnormal protrusions (abnormal precipitation portions) may be formed. Furthermore, when the metal foreign matter itself is contained in the adhesive, it may cause a decrease in insulation reliability.
  • the resin particles 101 are coated with a cationic polymer, and the non-conductive inorganic particles 102 are hydrophobized. It is coated with a treatment agent.
  • the zeta potential on the surface of the non-conductive inorganic particles 102 is shifted to minus due to the hydrophobicity.
  • an electrostatic force acts between the resin particles 101 and the non-conductive inorganic particles 102, and the non-conductive inorganic particles 102 are less likely to drop off from the surface of the resin particles 101.
  • the non-conductive inorganic particles 102 are less likely to drop off from the resin particles 101, so that the occurrence of abnormal precipitation can be suppressed and the generation of metallic foreign matters can be reduced when producing conductive particles.
  • the hydrophobizing agent is selected from the group consisting of a silazane hydrophobizing agent, a siloxane hydrophobizing agent, a silane hydrophobizing agent, and a titanate hydrophobizing agent.
  • the hydrophobizing agent may be selected from the group consisting of hexamethylene disilazane, polydimethylsiloxane, and N, N-dimethylaminotrimethylsilane.
  • the degree of hydrophobicity of the non-conductive inorganic particles 102 by the methanol titration method is, for example, 30% or more. In this case, a sufficient electrostatic force acts between the non-conductive inorganic particles 102 and the resin particles 101.
  • the difference in zeta potential between the resin particles 101 and the non-conductive inorganic particles 102 is, for example, 30 mV or more at pH 1 or more and pH 11 or less.
  • the resin particles 101 and the non-conductive inorganic particles 102 are firmly bonded by electrostatic force. Accordingly, it is possible to suitably suppress the non-conductive inorganic particles 102 from dropping from the resin particles 101 during the pretreatment step for forming the first layer 104 in the conductive particles 100a, the formation step of the first layer 104, and the like. .
  • the cationic polymer is selected from the group consisting of polyamine, polyimine, polyamide, polydiallyldimethylammonium chloride, polyvinylamine, polyvinylpyridine, polyvinylimidazole and polyvinylpyrrolidone.
  • the cationic polymer may be polyethyleneimine.
  • the charge density of the cationic polymer is increased, it is possible to favorably suppress the non-conductive inorganic particles 102 from dropping off.
  • the average particle diameter of the non-conductive inorganic particles 102 is, for example, 25 nm or more and 120 nm or less.
  • the conductive particles 100 a can have a large number of dense protrusions 109, and the nonconductive inorganic particles 102 are less likely to drop off from the resin particles 101.
  • the average particle diameter of the resin particles is, for example, 1 ⁇ m or more and 10 ⁇ m or less.
  • the conductivity of the anisotropic conductive adhesive depends on variations in the shape (height) of the electrodes of the connection structure. Sex and the like are less likely to change.
  • Non-conductive inorganic particles 102 are selected from the group consisting of silica, zirconia, alumina, and diamond.
  • the metal layer has a first layer 104 containing nickel.
  • the first layer 104 is a layer that covers the composite particles 103 by electroless plating.
  • the hardness of the conductive particles 100a can be increased. Accordingly, even when the conductive particles 100a are compressed, the first layer 104 formed on the non-conductive inorganic particles 102 and serving as a protruding portion is not easily crushed. Therefore, the conductive particles 100a can obtain a low conduction resistance.
  • the first layer 104 of the metal layer may have a plurality of conductive layers. At least one of the thickness, composition, and shape of these conductive layers may be different from each other. For example, the content of the metal that is the main component in the first layer 104 may increase as it approaches the surface in the thickness direction of the first layer 104.
  • a plurality of plating solutions may be used.
  • the first layer 104 having a plurality of conductive layers can be easily formed by using plating solutions having different metal concentrations.
  • the first layer 104 may be formed of a second plating solution having a different (higher) metal concentration than the first plating solution after the first plating solution is added or before the first plating solution is finished. It may be formed by starting to throw. In this case, the first layer 104 in which the metal concentration in the thickness direction gradually changes (increases) toward the surface can be formed. In addition, since the step of individually forming a plurality of conductive layers having different compositions is not necessary, the first layer 104 can be formed in a short time.
  • FIG. 3 is a schematic cross-sectional view showing conductive particles according to the second embodiment. 3 has the same configuration as the conductive particle 100a shown in FIG. 1 except that the conductive particle 100b shown in FIG. 3 has a second layer 105 provided on the first layer 104.
  • the second layer 105 may be a metal layer or an alloy layer.
  • the second layer 105 is a conductive layer provided so as to cover the first layer 104.
  • the thickness of the second layer 105 is, for example, 5 nm to 100 nm.
  • the thickness of the second layer 105 may be 5 nm or more, or 10 nm or more.
  • the thickness of the second layer 105 may be 30 nm or less.
  • the thickness of the second layer 105 can be made uniform when the second layer 105 is formed. For example, nickel) can be satisfactorily prevented from diffusing to the surface opposite to the second layer 105.
  • the thickness of the second layer 105 is calculated using a photograph taken by a TEM.
  • a cross section of the conductive particle 100b is cut out by an ultramicrotome method so as to pass near the center of the conductive particle 100b.
  • the cut section is observed at a magnification of 250,000 times using a TEM to obtain an image.
  • the thickness of the second layer 105 can be calculated from the cross-sectional area of the second layer 105 (FIG. 4) estimated from the obtained image.
  • component analysis is performed by component analysis using EDX attached to the TEM.
  • the second layer 105 is an average value of the thickness of 10 conductive particles.
  • the second layer 105 contains at least one selected from the group consisting of noble metals and cobalt.
  • the noble metal is palladium, rhodium, iridium, ruthenium, platinum, silver, or gold.
  • money the conduction
  • the second layer 105 functions as an antioxidant layer for the first layer 104 containing nickel. Therefore, the second layer 105 is formed on the first layer 104.
  • the thickness of the second layer 105 in the case of containing gold may be 30 nm or less. In this case, the balance between the reduction effect of the conduction resistance on the surface of the conductive particle 100b and the manufacturing cost is excellent. However, the thickness of the second layer 105 in the case of containing gold may exceed 30 nm.
  • the second layer 105 is preferably composed of at least one selected from the group consisting of palladium, rhodium, iridium, ruthenium and platinum. In this case, the oxidation of the surface of the conductive particle 100b can be suppressed, and the insulation reliability of the conductive particle 100b can be improved.
  • the second layer 105 is more preferably composed of at least one selected from the group consisting of palladium, rhodium, iridium, and ruthenium. In this case, even when the conductive particles 100b are compressed, the first layer 104 that becomes the protrusions 109 formed on the non-conductive inorganic particles 102 is suppressed from being crushed, and the resistance of the compressed conductive particles 100b is reduced. Increase is suppressed.
  • the second layer 105 is formed on the composite particles 103 covered with the first layer 104 by, for example, electroless plating after forming the first layer 104 in the fourth step of the first embodiment. .
  • the second layer 105 can be formed by, for example, electroless palladium plating.
  • Electroless palladium plating may use either a substitution type that does not use a reducing agent or a reduction type that uses a reducing agent.
  • MCA trade name, manufactured by World Metal Co., Ltd.
  • the reduction type include APP (trade name, manufactured by Ishihara Chemical Co., Ltd.) and the like.
  • the lower limit of the palladium content in the second layer 105 may be 90% by mass or more, 93% by mass or more, and 94% by mass based on the total amount of the second layer 105. % Or more.
  • the upper limit of the palladium content in the second layer 105 may be 99% by mass or less or 98% by mass or less based on the total amount of the second layer 105.
  • the reducing agent used in the electroless palladium plating solution is not particularly limited. Phosphorus-containing compounds such as acids, phosphorous acid, and alkali salts thereof; boron-containing compounds and the like can be used. In that case, the resulting second layer 105 includes a palladium-phosphorus alloy or a palladium-boron alloy. For this reason, it is preferable to adjust the concentration of the reducing agent, the pH, the temperature of the plating solution, and the like so that the palladium content in the second layer 105 falls within a desired range.
  • the second layer 105 contains rhodium
  • the second layer 105 can be formed by electroless rhodium plating, for example.
  • the supply source of rhodium used in the electroless rhodium plating solution include ammine rhodium hydroxide, ammine rhodium nitrate, ammine rhodium acetate, ammine rhodium sulfate, ammine rhodium sulfite, ammine rhodium bromide, and an ammine rhodium compound.
  • Examples of the reducing agent used in the electroless rhodium plating solution include hydrazine, sodium hypophosphite, dimethylamine borate, diethylamine borate, and sodium borohydride.
  • hydrazine is preferable.
  • a stabilizer or complexing agent (ammonium hydroxide, hydroxylamine salt, hydrazine dichloride, etc.) may be added to the electroless rhodium plating solution.
  • the temperature (bath temperature) of the electroless rhodium plating solution may be 40 ° C. or higher, or 50 ° C. or higher from the viewpoint of obtaining a sufficient plating rate.
  • the temperature of the plating solution may be 90 ° C. or lower or 80 ° C. or lower from the viewpoint of stably holding the electroless rhodium plating solution.
  • the second layer 105 can be formed by, for example, electroless iridium plating.
  • the source of iridium used in the electroless iridium plating solution include iridium trichloride, iridium tetrachloride, iridium tribromide, iridium tetrabromide, iridium hexachloride, tripotassium hexachloride, iridium hexachloride, iridium hexachloride Examples include sodium, disodium iridium hexachloride, tripotassium iridium hexabromide, dipotassium iridium hexabromide, tripotassium iridium hexaiodide, diiridium trissulfate, and iridium bissulfate.
  • Examples of the reducing agent used in the electroless iridium plating solution include hydrazine, sodium hypophosphite, dimethylamine borate, diethylamine borate, and sodium borohydride.
  • hydrazine is preferable.
  • a stabilizer or complexing agent may be added to the electroless iridium plating solution.
  • the stabilizer or complexing agent at least one selected from the group consisting of monocarboxylic acids, dicarboxylic acids and salts thereof may be added.
  • the monocarboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, lactic acid and the like.
  • the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, malic acid and the like.
  • the salt include compounds in which sodium, potassium, lithium or the like is bound as a counter ion to the carboxylic acid.
  • a stabilizer or a complexing agent can be used individually by 1 type or in combination of 2 or more types.
  • the pH of the electroless iridium plating solution may be 1 or more, or 2 or more from the viewpoint of suppressing corrosion of the plating object and obtaining a sufficient plating rate.
  • the pH of the electroless iridium plating solution may be 6 or less or 5 or less from the viewpoint that inhibition of the plating reaction is easily suppressed.
  • the temperature (bath temperature) of the electroless iridium plating solution may be 40 ° C. or higher, or 50 ° C. or higher from the viewpoint of obtaining a sufficient plating rate.
  • the temperature (bath temperature) of the electroless iridium plating solution may be 90 ° C. or less or 80 ° C. or less from the viewpoint of stably holding the electroless iridium plating solution.
  • the second layer 105 contains ruthenium
  • the second layer 105 can be formed by electroless ruthenium plating, for example.
  • electroless ruthenium plating solution for example, a commercially available plating solution can be used, and electroless ruthenium Ru (trade name, manufactured by Okuno Pharmaceutical Co., Ltd.) can be used.
  • the second layer 105 contains platinum
  • the second layer 105 can be formed by, for example, electroless platinum plating.
  • platinum used for the electroless platinum plating solution, for example, Pt (NH 3 ) 4 (NO 3 ) 2 , Pt (NH 3 ) 4 (OH) 2 , PtCl 2 (NH 3 ) 2 , Pt (NH) 3 ) 2 (OH) 2 , (NH 4 ) 2 PtCl 6 , (NH 4 ) 2 PtCl 4 , Pt (NH 3 ) 2 Cl 4 , H 2 PtCl 6 , and PtCl 2 .
  • Examples of the reducing agent used in the electroless platinum plating solution include hydrazine, sodium hypophosphite, dimethylamine borate, diethylamine borate, and sodium borohydride.
  • hydrazine is preferable.
  • a stabilizer or complexing agent (hydroxylamine chloride, hydrazine dichloride, ammonium hydroxide, EDTA, etc.) may be added to the electroless platinum plating solution.
  • the temperature (bath temperature) of the electroless platinum plating solution may be 40 ° C. or higher, or 50 ° C. or higher from the viewpoint of obtaining a sufficient plating rate.
  • the temperature (bath temperature) of the electroless platinum plating solution may be 90 ° C. or less or 80 ° C. or less from the viewpoint of stably holding the electroless platinum plating solution.
  • the pH of the electroless platinum plating solution may be 8-12.
  • the pH is 8 or more, platinum is sufficiently easily precipitated.
  • the pH is 12 or less, a good working environment can be easily secured.
  • the second layer 105 can be formed by, for example, electroless silver plating.
  • the silver supply source used in the electroless silver plating solution is not particularly limited as long as it is soluble in the plating solution.
  • silver nitrate, silver oxide, silver sulfate, silver chloride, silver sulfite, silver carbonate, silver acetate, silver lactate, silver sulfosuccinate, silver sulfonate, silver sulfamate, and silver oxalate are used.
  • a water-soluble silver compound can be used individually by 1 type or in combination of 2 or more types.
  • the reducing agent used in the electroless silver plating solution is not particularly limited as long as it has the ability to reduce the water-soluble silver compound in the electroless silver plating solution to metallic silver and is a water-soluble compound.
  • hydrazine derivatives, formaldehyde compounds, hydroxylamines, saccharides, Rossell salts, borohydride compounds, hypophosphites, DMAB, and ascorbic acid can be used.
  • a reducing agent can be used individually by 1 type or in combination of 2 or more types.
  • a stabilizer or complexing agent may be added to the electroless silver plating solution.
  • the stabilizer or complexing agent for example, sulfite, succinimide, hydantoin derivative, ethylenediamine, and ethylenediaminetetraacetic acid (EDTA) can be used.
  • EDTA ethylenediaminetetraacetic acid
  • a stabilizer or a complexing agent can be used individually by 1 type or in combination of 2 or more types.
  • additives such as known surfactants, pH adjusters, buffers, smoothing agents, stress relieving agents may be added to the electroless silver plating solution.
  • the electroless silver plating solution may be in the range of 0 to 80 ° C. as the solution temperature.
  • the temperature of the electroless silver plating solution is 0 ° C. or higher, the silver deposition rate is sufficiently high, and the time for obtaining a predetermined silver deposition amount can be shortened.
  • the temperature of the electroless silver plating solution is 80 ° C. or lower, it is possible to suppress the loss of the reducing agent due to the self-decomposition reaction and the decrease in the stability of the electroless silver plating solution.
  • the temperature is about 10 to 60 ° C., the stability of the electroless silver plating solution can be further improved.
  • the pH of the electroless silver plating solution (for example, reduced electroless silver plating solution) is, for example, 1 to 14.
  • the pH of the plating solution is about 6 to 13
  • the stability of the plating solution can be further improved.
  • an acid having an anion portion of the same kind as that of the water-soluble silver salt for example, sulfuric acid, water-soluble when silver sulfate is used as the water-soluble silver salt
  • Nitric acid is used when silver nitrate is used as the silver salt.
  • alkali metal hydroxide, ammonia or the like is used.
  • the second layer 105 contains gold
  • the second layer 105 can be formed by, for example, electroless gold plating.
  • the electroless gold plating solution include a displacement type gold plating solution (for example, product name “HGS-100” manufactured by Hitachi Chemical Co., Ltd.) and a reduction type gold plating solution (for example, product name “HGS- manufactured by Hitachi Chemical Co., Ltd.). 2000 ”) or the like.
  • the substitution type and the reduction type are compared, it is preferable to use the reduction type from the viewpoint that there are few voids and the covering area is easily secured.
  • the second layer 105 can be formed by, for example, electroless cobalt plating.
  • the cobalt supply source used in the electroless cobalt plating solution include cobalt sulfate, cobalt chloride, cobalt nitrate, cobalt acetate, and cobalt carbonate.
  • Examples of the reducing agent used in the electroless cobalt plating solution include hypophosphites such as sodium hypophosphite, ammonium hypophosphite, nickel hypophosphite, and hypophosphorous acid.
  • a stabilizer or a complexing agent (such as an aliphatic carboxylic acid) may be added to the electroless cobalt plating solution.
  • a stabilizer or a complexing agent can be used individually by 1 type or in combination of 2 or more types.
  • the temperature (bath temperature) of the electroless cobalt plating solution may be 40 ° C. or higher or 50 ° C. or higher from the viewpoint of obtaining a sufficient plating rate.
  • the temperature (bath temperature) of the electroless cobalt plating solution may be 90 ° C. or less or 80 ° C. or less from the viewpoint of stably holding the electroless cobalt plating solution.
  • the non-conductive inorganic particles 102 are less likely to drop off from the surfaces of the resin particles 101, as with the conductive particles 100a according to the first embodiment. For this reason, it becomes easy to control the number of the non-conductive inorganic particles 102 arranged on the surface of the resin particles 101, and good protrusions 109 are formed on the composite particles 103. Therefore, even when the connection structure using the anisotropic conductive adhesive containing the conductive particles 100b is stored under high temperature and high humidity, the conduction reliability is improved. In addition, since the number of non-conductive inorganic particles 102 that fall off from the resin particles 101 is reduced, abnormally grown protrusions are hardly generated on the composite particles 103. Therefore, when the conductive particles 100a are blended in the anisotropic conductive adhesive, the conductive particles 100b are less likely to conduct with each other, and the insulation reliability of the conductive particles 100b is improved.
  • the first layer 104 is the outermost layer of the conductive particles 100a.
  • the metal layer of the second embodiment has a second layer 105 provided on the first layer 104, and the second layer 105 contains a metal selected from the group consisting of noble metals and cobalt. In this case, the outermost layer of the conductive particles 100 b becomes the second layer 105.
  • the second layer 105 has a function of preventing elution of nickel from the first layer 104, the occurrence of nickel migration can be suppressed. In addition, since the second layer 105 is relatively difficult to oxidize, the conductive performance of the conductive particles 100b is unlikely to deteriorate. When the conductive particles 100b include the second layer 105, the number, size, and shape of the protrusions 109 can be highly controlled.
  • FIG. 5 is a schematic cross-sectional view showing the insulating coated conductive particles according to the present embodiment. 5 includes the conductive particles 100a according to the first embodiment and the insulating particles (insulating covering portion) 210 that covers at least a part of the surface of the first layer 104. The conductive particles 100a illustrated in FIG. .
  • the average particle diameter of the insulating particles 210 means an average particle diameter calculated from the diameter of a perfect circle having the same area as the area of the insulating particles 210 on the orthographic projection surface of the insulating particles 210.
  • the average particle diameter of the insulating particles 210 is, for example, 20 to 500 nm.
  • the average particle diameter of the insulating particles 210 is within the above range, for example, the insulating particles 210 adsorbed on the conductive particles 100a are likely to effectively act as an insulating film. Also, the conductivity in the pressurizing direction of the connection tends to be good.
  • the average particle diameter of the insulating particles 210 may be measured by, for example, a specific surface area conversion method by the BET method or an X-ray small angle scattering method.
  • the average particle size of the insulating particles 210 may be 1/10 or less with respect to the average particle size of the conductive particles 100a. It may be 1/15 or less.
  • the average particle diameter of the insulating particles 210 may be 1/20 or more with respect to the average particle diameter of the conductive particles 100a from the viewpoint of obtaining better insulation reliability.
  • the insulating particles 210 cover the surfaces of the conductive particles 100a so that the coverage of the insulating particles 210 with respect to the conductive particles 100a is, for example, 20 to 70%. From the viewpoint of more reliably obtaining the insulating and conductive effects, the coverage may be 20 to 60%, 25 to 60%, or 28 to 55%. “Coverage” means the ratio of the surface area of the insulating particles 210 in a concentric circle having a diameter 1 ⁇ 2 of the diameter of the insulating coated conductive particles 200 on the orthographic projection surface of the insulating coated conductive particles 200.
  • Examples of the insulating particles 210 covering the conductive particles 100a include organic polymer compound fine particles and inorganic oxide fine particles.
  • inorganic oxide fine particles are used as the insulating particles 210, the insulation reliability can be easily improved, and when organic polymer compound fine particles are used, the conduction resistance can be easily lowered.
  • the organic polymer compound may be any compound having heat softening properties, and specifically, polyethylene, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic. Acid ester copolymer, polyester, polyamide, polyurethane, polystyrene, styrene-divinylbenzene copolymer, styrene-isobutylene copolymer, styrene-butadiene copolymer, styrene- (meth) acrylic acid copolymer, ethylene-propylene Copolymers, (meth) acrylic ester rubbers, styrene-ethylene-butylene copolymers, phenoxy resins, solid epoxy resins and the like are used.
  • An organic polymer compound can be used individually by 1 type or in combination of 2 or more types.
  • the inorganic oxide examples include oxides containing at least one element selected from the group consisting of silicon, aluminum, zirconium, titanium, niobium, zinc, tin, cerium, and magnesium.
  • An inorganic oxide can be used individually by 1 type or in combination of 2 or more types.
  • silica is preferred.
  • silicas water-dispersed colloidal silica (SiO 2 ) is particularly suitable because it has a hydroxyl group on the surface, is excellent in binding properties with conductive particles, easily has a uniform particle size, and is inexpensive.
  • Examples of such commercially available fine particles of inorganic oxide include Snowtex, Snowtex UP (trade name, manufactured by Nissan Chemical Industries, Ltd.), and Quatron PL series (trade name, manufactured by Fuso Chemical Industries, Ltd.). Is mentioned.
  • the hydroxyl group can be modified to an amino group, a carboxyl group, an epoxy group or the like with a silane coupling agent or the like.
  • the average particle size of the inorganic oxide fine particles is 500 nm or less, it may be difficult to modify. In that case, the conductive particles 100a may be coated without modification.
  • the surface of the inorganic oxide fine particles when it has a hydroxyl group, it can be bonded to a hydroxyl group, a carboxyl group, an alkoxyl group, an alkoxycarbonyl group or the like of a surface treatment agent such as a silane coupling agent.
  • a surface treatment agent such as a silane coupling agent.
  • the bonding form include a covalent bond by dehydration condensation, a hydrogen bond, and a coordination bond.
  • a hydroxyl group is formed on the surface of the inorganic oxide fine particle using a compound having a mercapto group, sulfide group, disulfide group or the like that forms a coordinate bond with these particles in the molecule.
  • a functional group such as a carboxyl group, an alkoxyl group, or an alkoxycarbonyl group may be formed.
  • the compound include mercaptoacetic acid, 2-mercaptoethanol, methyl mercaptoacetate, mercaptosuccinic acid, thioglycerin, and cysteine.
  • the method for treating the above compound on the gold surface is not particularly limited, but the above compound such as mercaptoacetic acid is dispersed in an organic solvent such as methanol and ethanol in an amount of about 10 to 100 mmol / L, and the outermost layer is contained therein. It is possible to disperse the conductive particles 100a in which is gold.
  • Examples of the method of coating the surface of the conductive particles 100a with the insulating particles 210 include a method of alternately laminating polymer electrolytes and insulating particles.
  • a step of rinsing after conducting particles 100a are dispersed in a polymer electrolyte solution, the polymer electrolyte is adsorbed on the surface of the conductive particles 100a, and then rinsed.
  • (2) a step of rinsing after dispersing the conductive particles 100a in a dispersion solution of insulating particles, adsorbing the insulating particles on the surface of the conductive particles 100a, is performed.
  • insulating coated conductive particles 200 whose surfaces are coated with insulating particles 210 in which a polymer electrolyte and insulating particles are laminated can be manufactured.
  • the steps (1) and (2) may be in the order of (1) and (2) or in the order of (2) and (1).
  • the steps (1) and (2) may be repeated alternately.
  • polymer electrolyte for example, a polymer that is ionized in an aqueous solution and has a charged functional group in the main chain or side chain can be used.
  • a polymer compound having a positively charged functional group such as polyamines can be used, and the same cationic polymer as that used for the surface treatment of the resin particles 101 can be used.
  • polyethyleneimine (PEI) polyallylamine hydrochloride (PAH), polydiallyldimethylammonium chloride (PDDA), polyvinylpyridine (PVP), polylysine, polyacrylamide, and one or more types of polymers that give these polymers.
  • a copolymer or the like obtained by polymerizing the monomer can be used.
  • Polyethyleneimine is preferably used from the viewpoint of high charge density and strong binding force to negatively charged surfaces and materials.
  • the method of repeating the above steps (1) and (2) is called an alternating layering method (Layer-by-Layer assembly).
  • the alternating lamination method is described in G. This is a method for forming an organic thin film published in 1992 by Decher et al. (Thin Solid Films, 210/211, p831 (1992)). G.
  • a substrate (substrate, etc.) is alternately immersed in an aqueous solution of a polymer electrolyte (polycation) having a positive charge and a polymer electrolyte (polyanion) having a negative charge
  • a composite membrane (alternate laminated membrane) is obtained by laminating a set of polycations and polyanions adsorbed on a substrate by an attractive force.
  • the film grows by attracting the charge of the material formed on the substrate and the material having the opposite charge in the solution by electrostatic attraction. For this reason, when adsorption proceeds and charge neutralization occurs, no further adsorption occurs. Therefore, when reaching a certain saturation point, the film thickness does not increase any more.
  • Lvov et al. Applied an alternate lamination method to fine particles and reported a method of laminating a polymer electrolyte having a charge opposite to the surface charge of the fine particles using each fine particle dispersion such as silica, titania and ceria. (Langmuir, Vol. 13, (1997) p6195-6203).
  • silica fine particles having a negative surface charge and polydiallyldimethylammonium chloride (PDDA), polyethyleneimine (PEI), and the like, which are polycations having the opposite charge, are alternately used.
  • PDDA polydiallyldimethylammonium chloride
  • PEI polyethyleneimine
  • a fine particle laminated thin film in which silica fine particles and polymer electrolyte are alternately laminated can be formed.
  • the connection structure using the anisotropic conductive adhesive containing the insulating coated conductive particles 200 is heated at a high temperature. Even when stored under high humidity, the conduction reliability is improved.
  • the insulating particles 210 provided on the outer surface of the first layer 104 make it difficult for the first layers 104 of the conductive particles 100a to contact each other.
  • the foreign metal formed by coating the dropped non-conductive inorganic particles 102 with a metal is unlikely to exist in the adhesive. Therefore, it becomes difficult for the insulating coating conductive particles 200 to conduct well, and the insulation reliability of the connection structure using the insulating coating conductive particles 200 is also preferably improved.
  • anisotropic conductive adhesives for COG mounting have been required to have insulation reliability at a narrow pitch of about 10 ⁇ m.
  • Such insulation reliability can be realized by using the insulating coated conductive particles 200 according to the third embodiment.
  • the conductive particles in the insulating coated conductive particles 200 according to the third embodiment for example, the conductive particles 100b according to the second embodiment can be used instead of the conductive particles 100a.
  • the insulating coated conductive particles 200 can exhibit the effects of the conductive particles 100b according to the second embodiment in addition to the above effects.
  • the anisotropic conductive adhesive according to the fourth embodiment contains the conductive particles 100a according to the first embodiment and the adhesive in which the conductive particles 100a are dispersed.
  • the adhesive for example, a mixture of a heat-reactive resin and a curing agent is used.
  • the adhesive include a mixture of an epoxy resin and a latent curing agent, and a mixture of a radical polymerizable compound and an organic peroxide.
  • a paste or film adhesive is used as the adhesive.
  • a thermoplastic resin such as phenoxy resin, polyester resin, polyamide resin, polyester resin, polyurethane resin, (meth) acrylic resin, polyester urethane resin is blended into the adhesive. May be.
  • the conduction reliability is improved as in the first embodiment.
  • the number of non-conductive inorganic particles 102 that fall off from the resin particles 101 is reduced, abnormally grown protrusions are hardly generated on the composite particles 103.
  • the number of metallic foreign matters generated due to the non-conductive inorganic particles 102 dropped into the adhesive is reduced. Therefore, it becomes difficult for the conductive particles 100a dispersed in the anisotropic conductive adhesive to conduct, and the insulation reliability of the anisotropic conductive adhesive is also improved.
  • the conductive particles in the anisotropic conductive adhesive according to the fourth embodiment for example, the conductive particles 100b according to the second embodiment can be used instead of the conductive particles 100a.
  • the anisotropic conductive adhesive can achieve the effects of the conductive particles 100b according to the second embodiment.
  • Insulating coated conductive particles 200 may be used instead of the conductive particles 100a.
  • the anisotropic conductive adhesive can achieve the effects of the conductive particles 100b according to the third embodiment.
  • connection structure according to the fifth embodiment is disposed between a first circuit member having a first circuit electrode, a second circuit member having a second circuit electrode, and the first circuit member and the second circuit member, A connecting portion containing at least one of the conductive particles and the insulating coated conductive particles.
  • the connecting portion connects the first circuit member and the second circuit member to each other in a state where the first circuit electrode and the second circuit electrode are arranged to face each other.
  • the first circuit electrode and the second circuit electrode are electrically connected to each other through the deformed conductive particles or the insulating coated conductive particles.
  • FIG. 6 is a schematic cross-sectional view showing a connection structure according to the fifth embodiment.
  • a connection structure 300 illustrated in FIG. 6 includes a first circuit member 310 and a second circuit member 320 that face each other, and a connection portion 330 that is disposed between the first circuit member 310 and the second circuit member 320.
  • Examples of the connection structure 300 include portable products such as a liquid crystal display, a personal computer, a mobile phone, a smartphone, and a tablet.
  • the first circuit member 310 includes a circuit board (first circuit board) 311 and a circuit electrode (first circuit electrode) 312 disposed on the main surface 311a of the circuit board 311.
  • the second circuit member 320 includes a circuit board (first circuit board) 321 and circuit electrodes (second circuit electrodes) 322 arranged on the main surface 321 a of the circuit board 321.
  • circuit members 310 and 320 include chip components such as an IC chip (semiconductor chip), a resistor chip, a capacitor chip, and a driver IC; a rigid-type package substrate. These circuit members are provided with circuit electrodes, and generally have many circuit electrodes. Specific examples of the other of the circuit members 310 and 320 (the circuit member to which the one circuit member is connected) include a flexible tape substrate having metal wiring, a flexible printed wiring board, and indium tin oxide (ITO). Examples thereof include a wiring substrate such as a glass substrate. For example, by using a film-like anisotropic conductive adhesive, these circuit members can be connected efficiently and with high connection reliability. For example, the anisotropic conductive adhesive according to the fourth embodiment is suitable for COG mounting or COF mounting on a wiring board of a chip component having many fine circuit electrodes.
  • ITO indium tin oxide
  • connection portion 330 includes a cured product 332 of an adhesive and insulating coating conductive particles 200 dispersed in the cured product 332.
  • connection part 330 for example, a film-like anisotropic conductive adhesive described in the fourth embodiment is used.
  • the circuit electrode 312 and the circuit electrode 322 that face each other are electrically connected via the insulating coating conductive particles 200. More specifically, as shown in FIG. 6, the conductive particles 100 a in the insulating coated conductive particles 200 are deformed by compression and are electrically connected to both the circuit electrodes 312 and 322.
  • the insulating particles 210 are interposed between the conductive particles 100a in the direction intersecting the compressing direction, so that the insulation between the insulating coated conductive particles 200 is maintained. Therefore, the insulation reliability at a narrow pitch (for example, a pitch of 10 ⁇ m level) can be further improved.
  • the conductive particles 100 a and 100 b that are not covered with insulation may be used instead of the insulating coated conductive particles 200.
  • a first circuit member 310 having a circuit electrode 312 and a second circuit member 320 having a circuit electrode 322 are arranged such that the circuit electrode 312 and the circuit electrode 322 face each other, and It is obtained by interposing an anisotropic conductive adhesive between the circuit member 310 and the second circuit member 320, and heating and pressurizing them to electrically connect the circuit electrode 312 and the circuit electrode 322.
  • the first circuit member 310 and the second circuit member 320 are bonded together by a cured product 332 of an adhesive.
  • FIG. 7 is a schematic cross-sectional view for explaining an example of the manufacturing method of the connection structure shown in FIG.
  • the anisotropic conductive adhesive is thermoset to produce a connection structure.
  • a first circuit member 310 and an anisotropic conductive adhesive 330a are prepared.
  • an adhesive film (anisotropic conductive adhesive film) formed into a film shape is used as the anisotropic conductive adhesive 330a.
  • the anisotropic conductive adhesive 330a contains the insulating coating conductive particles 200 and the insulating adhesive 332a.
  • the anisotropic conductive adhesive 330a is placed on the main surface 311a of the first circuit member 310 (the surface on which the circuit electrode 312 is formed). Then, as shown in FIG. 7A, the anisotropic conductive adhesive 330 a is pressurized along the direction A and the direction B. Thereby, as shown in FIG. 7B, the anisotropic conductive adhesive 330 a is laminated on the first circuit member 310.
  • the second circuit member 320 is placed on the anisotropic conductive adhesive 330a so that the circuit electrode 312 and the circuit electrode 322 face each other. And the whole (the 1st circuit member 310 and the 2nd circuit member 320) is pressurized along the direction A and the direction B shown by FIG.7 (c), heating the anisotropic conductive adhesive 330a.
  • the anisotropic conductive adhesive 330a is cured by heating to form the connection portion 330, and a connection structure 300 as shown in FIG. 6 is obtained.
  • the anisotropic conductive adhesive may be in the form of a paste.
  • the insulating coating conductive particles 200 according to the third embodiment are included in the connection portion 330.
  • the circuit electrode 312 and the circuit electrode 322 are electrically connected satisfactorily through the insulating coating conductive particles 200. For this reason, even when the area of the circuit electrode 312 and the circuit electrode 322 is small and the number of the insulating coating conductive particles 200 captured between the circuit electrodes 312 and 322 is small, excellent conduction reliability over a long period of time. Sex is demonstrated.
  • the insulating coated conductive particles 200 include the insulating particles 210, the first layers 104 of the insulating coated conductive particles 200 in the connection portion 330 are less likely to contact each other.
  • connection structure 300 is also preferably improved.
  • the average particle diameter of the non-conductive inorganic particles is 25 nm to 120 nm, but the present invention is not limited to this.
  • the average particle size of the resin particles is not necessarily 1 to 10 ⁇ m.
  • Step a Coating of resin particle surface with cationic polymer 2 g of crosslinked polystyrene particles having an average particle size of 3.0 ⁇ m (trade name “Soliostar”, manufactured by Nippon Shokubai Co., Ltd.) were added to an average molecular weight of 70,000 (MW 7). 10 g of a 30% by mass polyethyleneimine aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) was added to an aqueous solution dissolved in 100 ml of pure water and stirred at room temperature for 15 minutes.
  • the resin particles were taken out by filtration using a ⁇ 3 ⁇ m membrane filter (manufactured by Merck Millipore).
  • the resin particles on the membrane filter were washed twice with 200 g of ultrapure water to remove non-adsorbed polyethyleneimine to obtain resin particles adsorbed with polyethyleneimine.
  • Step b Coating of non-conductive inorganic particles with a hydrophobizing agent
  • the vapor-phase hydrophilic spherical silica powder having an average particle size of 60 nm was used as non-conductive inorganic particles.
  • 100 g of this spherical silica powder was placed in a vibrating fluidized bed apparatus (manufactured by Chuo Kako Co., Ltd., trade name “vibrating fluidized bed apparatus VUA-15 type”). Next, 1.5 g of water was sprayed and mixed for 5 minutes while fluidizing the spherical silica with air circulated by a suction blower.
  • HMDS hexamethylene disilazane
  • TSL-8802 Momentive Performance Materials Japan GK
  • Palladium catalyst provision process 2.05g of particle
  • a 3 ⁇ m membrane filter manufactured by Merck Millipore
  • particles A are added to 0.5% by mass dimethylamine borane solution adjusted to pH 6.0, and stirred for 5 minutes at 60 ° C. while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W, and the palladium catalyst is fixed. 2.05 g of modified particles B were obtained. And after immersing 2.05 g of particle
  • Step e Formation of layer a of first layer
  • the particle B dispersion obtained in step d is diluted with 1000 mL of water heated to 80 ° C.
  • 1 mL of 1 g / L bismuth nitrate aqueous solution is added as a plating stabilizer. did.
  • electroless nickel for forming a layer having the following composition an aqueous solution containing the following components and 1 mL of 1 g / L bismuth nitrate aqueous solution per liter of plating solution; the same applies hereinafter
  • 80 mL of plating solution was added dropwise at a dropping rate of 5 mL / min.
  • the composition of the electroless nickel plating solution for forming the first layer a is as follows. Nickel sulfate ... 400g / L Sodium hypophosphite ... 150g / L Sodium citrate ... 120g / L Bismuth nitrate aqueous solution (1 g / L) ... 1 mL / L
  • Step f Formation of b layer of first layer 4.05 g of particles C obtained in step e were washed with water and filtered, and then dispersed in 1000 mL of water heated to 70 ° C. To this dispersion, 1 mL of a 1 g / L bismuth nitrate aqueous solution was added as a plating stabilizer. Subsequently, 20 mL of electroless nickel plating solution for b layer formation of the following composition was dripped at the dripping speed
  • the filtrate was washed with water and then dried with a vacuum dryer at 80 ° C.
  • particles D conductive particles having a b layer made of a nickel-phosphorus alloy film with a thickness of 20 nm shown in Table 1-1 were formed.
  • the particle D obtained by forming the b layer was 4.55 g.
  • the composition of the electroless nickel plating solution for forming the b layer of the first layer is as follows. Nickel sulfate ... 400g / L Sodium hypophosphite ... 150g / L Sodium tartrate dihydrate ... 60g / L Bismuth nitrate aqueous solution (1 g / L) ... 1 mL / L
  • the degree of hydrophobicity of the conductive particles was measured by the following method. First, 50 ml of ion exchange water and 0.2 g of a sample (conductive particles) are put in a beaker, and methanol is dropped from a burette while stirring with a magnetic stirrer. As the methanol concentration in the beaker increases, the powder gradually settles, and the mass fraction of methanol in the methanol-water mixed solution at the end point when the total amount of the powder settles is expressed as the hydrophobicity (%) of the conductive particles. did.
  • the particle size of the non-conductive inorganic particles was determined by analyzing an image obtained by observing at a magnification of 100,000 times with an SEM (trade name “S-4800” manufactured by Hitachi High-Technologies Corporation). Measure the area. Next, the diameter when the particles were converted into a circle was calculated as the average particle diameter of the non-conductive inorganic particles. Further, the ratio of the standard deviation of the particle diameter to the obtained average particle diameter was calculated as a percentage, and was defined as CV.
  • the zeta potential of various particles to be measured was measured by the following method.
  • Zetasizer ZS trade name, manufactured by Malvern Instruments
  • the dispersion was diluted so that various particles to be measured were about 0.02% by mass.
  • the zeta potential was measured under a total of four conditions including methanol alone, pH 1, ph7 and pH 10.5 methanol and a mixed solvent of ion exchange water.
  • the proportion of methanol was 10% by mass, and the pH was adjusted with sulfuric acid or potassium hydroxide.
  • the zeta potential was measured for each particle to be measured.
  • a cross section was cut out by an ultramicrotome method so as to pass through the vicinity of the center of the obtained conductive particles. This cross section was observed at a magnification of 250,000 times using TEM (trade name “JEM-2100F” manufactured by JEOL Ltd.). From the obtained image, the cross-sectional areas of the a-layer, b-layer and second layer of the first layer were estimated, and the film thicknesses of the a-layer, b-layer and second layer of the first layer were calculated from the cross-sectional areas (implementation) In Example 1, since the second layer was not formed, only the thicknesses of the a layer and the b layer of the first layer were measured.
  • the cross-sectional area of each layer in the cross section with a width of 500 nm was read by image analysis, and the height when converted into a rectangle with a width of 500 nm was calculated as the film thickness of each layer.
  • Table 1-1 shows the average values of the film thicknesses calculated for 10 conductive particles.
  • the content (purity) of the element in the first layer a and b was calculated. Details of a method for producing a sample in the form of a thin film (cross-sectional sample of conductive particles), details of a mapping method by EDX, and details of a method for calculating the content of elements in each layer will be described later.
  • the coverage of the non-conductive inorganic particles was evaluated based on images obtained by observing the particles A and B with a SEM at 30,000 times.
  • FIG. 8 the SEM image which observed the particle
  • ⁇ Diameter and number of non-conductive inorganic particles The diameter of the non-conductive inorganic particles present in the concentric circles having a diameter half that of the particles A and B in the orthographic projection planes of the particles A and B obtained after the steps c and d. Numbers were calculated respectively. By calculating the number of nonconductive inorganic particles in each of particles A and B, the effect of step d (palladium catalyst application step) on the adsorptivity of the nonconductive inorganic particles to the resin particle surface was evaluated.
  • the number of silica particles was evaluated based on images obtained by observing particles A and particles B with a SEM at a magnification of 100,000 times. The area of each non-conductive inorganic particle was measured, and the diameter of a perfect circle having the same area as that area was calculated as the diameter of the non-conductive inorganic particle. Non-conductive inorganic particles were classified based on the diameter ranges shown in Table 1-2, and the number of non-conductive inorganic particles in each range was determined.
  • grains B after the process d in Example 1 is shown.
  • FIG. 9 is a portion within a concentric circle having a diameter that is 1/2 the diameter of particle B.
  • FIG. 11 is a portion within the same circle having a diameter that is 1/2 the diameter of particle D.
  • a cross-sectional sample having a thickness of 60 nm ⁇ 20 nm for conducting TEM analysis and STEM / EDX analysis from the cross section of the conductive particles (hereinafter referred to as “thin film section for TEM measurement”) is prepared as follows using an ultramicrotome method. did.
  • Conductive particles were dispersed in the casting resin for stable thinning. Specifically, 10 g of a mixture of bisphenol A liquid epoxy resin, butyl glycidyl ether, and other epoxy resin (Refinetech Co., Ltd., trade name “Epomount Main Agent 27-771”) is mixed with diethylenetriamine (Refinetech Corporation). (Product name “Epomount Curing Agent 27-772”) 1.0 g was mixed. It stirred using the spatula and it confirmed visually that it mixed uniformly. After adding 0.5 g of dried conductive particles to 3 g of this mixture, the mixture was stirred with a spatula until uniform.
  • the mixture containing the conductive particles was poured into a mold for resin casting (DSK, manufactured by Dosaka EM Co., Ltd., trade name “silicone embedding plate type II”), and allowed to stand at room temperature (room temperature) for 24 hours. . After confirming that the casting resin was hardened, a resin casting of conductive particles was obtained.
  • DSK manufactured by Dosaka EM Co., Ltd., trade name “silicone embedding plate type II”
  • a thin film slice for TEM measurement was prepared from a resin cast containing conductive particles.
  • EM-UC6 manufactured by Leica Microsystems Co., Ltd.
  • a thin film slice for TEM measurement can be cut out using a glass knife fixed to the main body of the ultramicrotome as shown in FIG. The tip of the resin casting was trimmed until it became a shape.
  • trimming was performed so that the cross-sectional shape of the tip of the resin casting was a substantially rectangular parallelepiped having a length of 200 to 400 ⁇ m and a width of 100 to 200 ⁇ m. .
  • the reason why the horizontal length of the cross section is set to 100 to 200 ⁇ m is to reduce friction generated between the diamond knife and the sample when a thin film section for TEM measurement is cut out from a resin casting. This makes it easy to prevent wrinkling and bending of the thin film slice for TEM measurement, and facilitates production of the thin film slice for TEM measurement.
  • a diamond knife with a boat manufactured by DIATONE, trade name “Cryo Wet”, blade width 2.0 mm, blade angle 35 °
  • DIATONE trade name “Cryo Wet”
  • blade width 2.0 mm blade angle 35 °
  • blade angle 35 ° blade angle
  • Adjusting the vertical angle means adjusting the vertical angle of the sample holder so that the surface of the sample and the direction in which the knife advances are parallel to each other, as shown in FIG.
  • Adjusting the angle in the left-right direction means adjusting the angle in the left-right direction of the knife so that the blade edge of the knife and the sample surface are parallel, as shown in FIG.
  • Adjustment of clearance angle means adjusting the minimum angle formed by the surface of the knife edge on the sample side and the direction in which the knife proceeds, as shown in FIG.
  • the clearance angle is preferably 5 to 10 °.
  • the distance between the sample and the diamond knife is made closer, the blade speed is 0.3 mm / second, and the thinning thickness of the thin film is 60 nm ⁇ 20 nm.
  • the blade speed is 0.3 mm / second, and the thinning thickness of the thin film is 60 nm ⁇ 20 nm.
  • a thin film slice for TEM measurement was floated on the surface of the ion exchange water.
  • a copper mesh for TEM measurement (copper mesh with a microgrid) was pressed from the upper surface of the thin film slice for TEM measurement floated on the water surface, and the thin film slice for TEM measurement was adsorbed to the copper mesh to obtain a TEM sample. Since the thin film slice for TEM measurement obtained by the microtome does not exactly match the set value of the cut-out thickness of the microtome, a set value for obtaining a desired thickness is obtained in advance.
  • mapping method using EDX Details of the mapping method by EDX will be described.
  • the thin film slice for TEM measurement was fixed together with a copper mesh to a sample holder (trade name “Beryllium sample biaxial tilt holder, EM-31640” manufactured by JEOL Ltd.) and inserted into the TEM.
  • a sample holder trade name “Beryllium sample biaxial tilt holder, EM-31640” manufactured by JEOL Ltd.
  • the electron beam irradiation system was switched to the STEM mode.
  • JEOL Simple Image Viewer (Version 1.3.5)” (manufactured by JEOL Ltd.), and use it for TEM measurement. Thin film sections were observed. A portion suitable for EDX measurement was searched for and photographed in the cross section of the conductive particles observed therein.
  • location suitable for measurement means a location where the cross section of the metal layer can be observed by cutting near the center of the conductive particles. The part where the cross section is inclined and the part cut at a position shifted from the vicinity of the center of the conductive particles were excluded from the measurement target.
  • the observation magnification was 250,000 times, and the number of pixels of the STEM observation image was 512 points vertically and 512 points horizontally. Observation under this condition gives an observation image with a viewing angle of 600 nm. However, care should be taken because the viewing angle may change even at the same magnification when the apparatus is changed.
  • the resin particles of the conductive particles and the casting resin are contracted and thermally expanded, and the sample is deformed or moved during the measurement. End up.
  • the measurement site was irradiated with an electron beam for about 30 minutes to 1 hour in advance, and analysis was performed after confirming that the deformation and movement had subsided.
  • EDX In order to perform STEM / EDX analysis, EDX was moved to the measurement position, and EDX measurement software “Analysis Station” (manufactured by JEOL Ltd.) was started.
  • a focusing diaphragm device for focusing an electron beam at a target location is used.
  • the electron beam spot diameter is in the range of 0.5 to 1.0 nm so that the number of detected characteristic X-rays (CPS: Counts Per Second) is 10,000 CPS or more. Adjusted. After the measurement, in the EDX spectrum obtained simultaneously with the mapping measurement, it was confirmed that the peak height derived from the K ⁇ ray of nickel was at least 5,000 Counts or more. At the time of data acquisition, the number of pixels was 256 points in the vertical direction and 256 points in the horizontal direction with the same viewing angle as that in the STEM observation. The integration time for each point was 20 milliseconds, and the measurement was performed once.
  • CPS Counts Per Second
  • EDX mapping data From the obtained EDX mapping data, EDX spectra in the first layer, the electroless nickel plating precipitation nuclei, and the second layer were extracted as needed, and the element abundance ratio in each part was calculated. However, when calculating the quantitative value, the sum of the proportions of the noble metal, nickel and phosphorus was 100% by mass, and the mass% concentration of each element was calculated.
  • the elements other than the above were excluded when calculating the quantitative values because the ratios were likely to fluctuate for the following reasons.
  • the ratio of carbon increases or decreases depending on the influence of impurities adsorbed on the surface of the sample when the carbon support film used in the mesh for TEM measurement or electron beam irradiation.
  • the proportion of oxygen may be increased by air oxidation between the preparation of the TEM sample and the measurement. Copper will be detected from the copper mesh used for TEM measurement.
  • Measurement of the number of metal foreign objects having an outer diameter of 1 ⁇ m or more is performed by observing 1000 conductive particles at a magnification of 5,000 by SEM, and the number of metal foreign objects having an outer diameter of 1 ⁇ m or more found during the observation of 1000 conductive particles. I counted.
  • Presence / absence of protrusions (abnormal precipitates) exceeding 500 nm in length was determined by the method schematically shown in FIG. Specifically, 1000 conductive particles 400 were observed by SEM at a magnification of 30,000, and a straight line connecting both ends in the diameter direction at the base end of the abnormal precipitation portion 401 (the valleys and valleys on both sides of the abnormal precipitation portion 401 were The length 402 of the abnormal precipitation portion 401 was obtained by measuring the distance from the connected straight line) to the apex of the abnormal precipitation portion 401 in the vertical direction. Then, the number of conductive particles having abnormal precipitation portions exceeding 500 nm in length was counted.
  • the average particle size of the synthesized insulating particles was measured by analyzing an image taken by SEM.
  • the average particle size of the insulating particles was 315 nm.
  • the Tg (glass transition point) of the synthesized insulating particles was measured using DSC (trade name “DSC-7”, manufactured by Perkin Elmer Co., Ltd.), sample amount: 10 mg, temperature increase rate: 5 ° C./min, measurement atmosphere: Measured under air conditions.
  • the weight average molecular weight of the silicone oligomer was measured by a gel permeation chromatography (GPC) method and calculated by using a standard polystyrene calibration curve.
  • GPC gel permeation chromatography
  • a pump manufactured by Hitachi, Ltd., trade name “L-6000”
  • a column Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (or more, Hitachi, Ltd.)
  • a detector manufactured by Hitachi, Ltd., trade name “L-3300 type RI”.
  • Tetrahydrofuran (THF) was used as an eluent, the measurement temperature was 40 ° C., and the flow rate was 2.05 mL / min.
  • a reaction solution was prepared by dissolving 8 mmol of mercaptoacetic acid in 200 ml of methanol.
  • 2 g of conductive particles particle D in Example 1 was added to the reaction solution, and the mixture was stirred at room temperature for 2 hours with a three-one motor and a stirring blade having a diameter of 45 mm.
  • 2 g of conductive particles having a carboxyl group on the surface was obtained by filtering using a membrane filter (manufactured by Merck Millipore) having a pore size of 3 ⁇ m.
  • a 30% polyethyleneimine aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) having a weight average molecular weight of 70,000 was diluted with ultrapure water to obtain a 0.3 mass% polyethyleneimine aqueous solution.
  • 2 g of the conductive particles having a carboxyl group on the surface were added to a 0.3% by mass polyethyleneimine aqueous solution and stirred at room temperature for 15 minutes. Thereafter, the conductive particles were filtered using a membrane filter (manufactured by Merck Millipore) having a pore size of 3 ⁇ m, and the filtered conductive particles were put in 200 g of ultrapure water and stirred at room temperature for 5 minutes.
  • the conductive particles were filtered using a membrane filter (manufactured by Merck Millipore) having a pore size of 3 ⁇ m, and washed twice with 200 g of ultrapure water on the membrane filter. By performing these operations, unimsorbed polyethyleneimine was removed, and conductive particles whose surface was coated with an amino group-containing polymer were obtained.
  • a membrane filter manufactured by Merck Millipore
  • the insulating particles were treated with a silicone oligomer to prepare a methanol dispersion medium of insulating particles having a glycidyl group-containing oligomer on the surface (a methanol dispersion medium of insulating particles).
  • the conductive particles whose surface was coated with an amino group-containing polymer were immersed in methanol, and a methanol dispersion medium of insulating particles was dropped into the methanol to produce insulating coated conductive particles.
  • the obtained insulating coated conductive particles were treated with a condensing agent and octadecylamine and washed to make the surface hydrophobic. Thereafter, the film was heat-dried at 80 ° C. for 1 hour to produce insulating coated conductive particles.
  • the average coverage of the conductive particles by the insulating particles was measured by analyzing an image taken by SEM, it was about 30%.
  • the insulating coated conductive particles were dispersed so as to be 9% by volume based on the total amount of the adhesive solution, thereby obtaining a dispersion.
  • the obtained dispersion is applied to a separator (silicone-treated polyethylene terephthalate film, thickness 40 ⁇ m) using a roll coater, dried by heating at 90 ° C. for 10 minutes, and has an anisotropic conductivity of 25 ⁇ m in thickness.
  • An adhesive film was produced on the separator.
  • gold bump (1) area: about 20 ⁇ m ⁇ about 40 ⁇ m, height: 15 ⁇ m
  • gold bump (2) area: about 30 ⁇ m ⁇ about 40 ⁇ m, high And a chip (1.7 mm ⁇ 20 mm, thickness: 0.5 ⁇ m) each provided with 362 gold bumps (3) (area: about 40 ⁇ m ⁇ about 40 ⁇ m, height: 15 ⁇ m)
  • IZO Connection with a glass substrate with a circuit was performed according to the following procedures i) to iii) to obtain a connection structure.
  • the space of the gold bump (1) was 6 ⁇ m, the space of the gold bump (2) was 8 ⁇ m, and the space of the gold bump (3) was 10 ⁇ m.
  • a space corresponds to the distance between gold bumps.
  • An anisotropic conductive adhesive film (2 mm ⁇ 24 mm) was attached to a glass substrate with an IZO circuit at 80 ° C. and 0.98 MPa (10 kgf / cm 2 ).
  • the separator was peeled off, and the bumps of the chip and the glass substrate with IZO circuit were aligned.
  • Heating and pressing were performed from above the chip under the conditions of 190 ° C., 40 gf / bump, and 10 seconds to bond the chip and the glass substrate, and to electrically connect the chip bump and the IZO circuit.
  • connection structure The conduction resistance test and the insulation resistance test of the obtained connection structure were performed as follows.
  • connection resistance test In the connection between the chip electrode (bump) and the IZO circuit, the initial value of the conduction resistance and the conduction resistance after the moisture absorption heat resistance test (left at 100, 300, 500, 1000, 2000 hours under conditions of a temperature of 85 ° C. and a humidity of 85%) The value of was measured.
  • the connection region between the chip electrode (bump) and the IZO circuit was about 20 ⁇ m ⁇ about 40 ⁇ m, about 30 ⁇ m ⁇ about 40 ⁇ m, and about 40 ⁇ m ⁇ about 40 ⁇ m. In the connection region of about 20 ⁇ m ⁇ about 40 ⁇ m, the chip electrode and the IZO circuit were set to be connected by three conductive particles (trapping conductive particles).
  • connection area of about 30 ⁇ m ⁇ about 40 ⁇ m the chip electrode and the IZO circuit were set to be connected by six conductive particles.
  • connection area of about 40 ⁇ m ⁇ about 40 ⁇ m the chip electrode and the IZO circuit were set to be connected by 10 conductive particles.
  • Table 6-1 The results of evaluating the conduction resistance from the average value obtained according to the following criteria are shown in Table 6-1. When the number of bumps was 6, and the following A or B criteria were satisfied after 500 hours of the moisture absorption heat test, it was evaluated that the conduction resistance was good.
  • Insulation resistance test As the insulation resistance between the chip electrodes (bumps), the initial value of the insulation resistance and the value of the insulation resistance after migration test (temperature, 60 ° C., humidity 90%, 20 V application for 100, 300, 1000, 2000 hours) And measured. Measurement was performed on 20 samples, and the ratio of samples having an insulation resistance value of 10 9 ⁇ or more was calculated among all 20 samples. The measurement was performed for each of the gold bumps (1) to (3). That is, the insulation resistance test was performed for each of the gold bump spaces of 6 ⁇ m, 8 ⁇ m, and 10 ⁇ m. The insulation resistance was evaluated from the obtained ratio according to the following criteria. The results are shown in Table 6-1.
  • Example 2 In the same manner as in Example 1 except that the gas phase method hydrophilic spherical silica powder having an average particle size of 60 nm was changed to the gas phase method hydrophilic spherical silica powder having an average particle size of 25 nm in (Step b) of Example 1.
  • the conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-1, Table 1-2, and Table 6-1.
  • Example 3 In the same manner as in Example 1 except that the vapor-phase hydrophilic spherical silica powder having an average particle size of 60 nm was changed to a vapor-phase hydrophilic spherical silica powder having an average particle size of 40 nm in (Step b) of Example 1.
  • the conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-1, Table 1-2, and Table 6-1.
  • Example 4 In the same manner as in Example 1 except that the gas phase method hydrophilic spherical silica powder having an average particle size of 60 nm was changed to the gas phase method hydrophilic spherical silica powder having an average particle size of 80 nm in (Step b) of Example 1.
  • the conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-1, Table 1-2, and Table 6-1.
  • Example 5 In the same manner as in Example 1 except that the gas phase method hydrophilic spherical silica powder having an average particle size of 60 nm was changed to the gas phase method hydrophilic spherical silica powder having an average particle size of 100 nm in (Step b) of Example 1.
  • the conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-3, Table 1-4, and Table 6-1.
  • Example 6> In the same manner as in Example 1 except that the gas phase method hydrophilic spherical silica powder having an average particle size of 60 nm was changed to the gas phase method hydrophilic spherical silica powder having an average particle size of 120 nm in (Step b) of Example 1.
  • the conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-3, Table 1-4, and Table 6-2.
  • Example 7 In (step d) of Example 1, as a palladium catalyst solution, adjusted to pH 10.5 and containing 8% by mass of a palladium catalyst (manufactured by Atotech Japan Co., Ltd., trade name “Atotech Neogant 834”) Except having used 100 mL of liquids, it carried out similarly to Example 1, and produced the electroconductive particle, the insulation coating electroconductive particle, the anisotropically conductive adhesive film, and the connection structure, and evaluated the electroconductive particle and the connection structure. . The results are shown in Table 1-3, Table 1-4, and Table 6-2.
  • Example 8> In (Step b) of Example 1, gas phase method hydrophilic spherical silica powder having an average particle size of 25 nm was used as the silica powder, and in (Step d) of Example 1, pH 10 was used as the palladium catalyzed liquid.
  • the connection structure was produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-1, Table 2-2 and Table 6-2.
  • Example 9 a vapor phase hydrophilic spherical silica powder having an average particle size of 40 nm was used as the silica powder, and in Example 1 (step d), instead of 100 mL of the palladium-catalyzed solution.
  • conductive particles, insulating coated conductive particles, anisotropic conductivity were obtained in the same manner as in Example 1 except that 100 mL of a palladium-catalyzed solution containing 8% by mass of Atotech Neogant 834 was adjusted to pH 10.5.
  • the production of the adhesive film and the connection structure, and the evaluation of the conductive particles and the connection structure were performed. The results are shown in Table 2-1, Table 2-2 and Table 6-2.
  • Example 10 In (Step b) of Example 1, a vapor-phase hydrophilic spherical silica powder having an average particle size of 80 nm was used as the silica powder, and in Example 1 (Step d), a pH of 10 was used as the palladium-catalyzed liquid.
  • the connection structure was produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-1, Table 2-2 and Table 7-1.
  • Example 11 In (Step b) of Example 1, gas phase method hydrophilic spherical silica powder having an average particle diameter of 100 nm was used as the silica powder, and in (Step d) of Example 1, pH 10 was used as the palladium-catalyzed liquid.
  • the connection structure was produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-1, Table 2-2 and Table 7-1.
  • Example 12 In (Step b) of Example 1, gas phase method hydrophilic spherical silica powder having an average particle size of 120 nm was used as the silica powder, and in (Step d) of Example 1, pH 10 was used as the palladium catalyzed liquid.
  • the connection structure was produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-3, Table 2-4, and Table 7-1.
  • Example 13> Instead of (Step b) of Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film were produced in the same manner as Example 1 except that non-conductive inorganic particles were produced by the method shown below. The connection structure was manufactured, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-3, Table 2-4, and Table 7-1.
  • Example 13 first, a vapor phase hydrophilic spherical silica powder having an average particle diameter of 100 nm was used, and 100 g of the spherical silica powder was vibrated with a vibrating fluidized bed apparatus (trade name “vibrating fluidized bed apparatus VUA-15 type, manufactured by Chuo Kako Co., Ltd.). )). Next, without using the circulating gas, spherical silica was fluidized with compressed air by a compressor with the upper part of the apparatus being opened, and 3.0 g of water was sprayed and fluidized and mixed for 5 minutes.
  • a vibrating fluidized bed apparatus trade name “vibrating fluidized bed apparatus VUA-15 type, manufactured by Chuo Kako Co., Ltd.
  • HMDS hexamethylene disilazane
  • TSL-8802 Momentive Performance Materials Japan GK
  • Example 14> Instead of (Step b) of Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film were produced in the same manner as Example 1 except that non-conductive inorganic particles were produced by the method shown below. The connection structure was manufactured, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-3, Table 2-4, and Table 7-1.
  • Example 14 first, vapor phase hydrophilic spherical silica powder having an average particle diameter of 100 nm was used, and 100 g of spherical silica powder was mixed with a vibrating fluidized bed apparatus (trade name “Vibrated Fluidized Bed Apparatus VUA-15, manufactured by Chuo Kako Co., Ltd.). Type "). Next, 3.5 g of water was sprayed while fluidizing the spherical silica with air circulated by a suction blower and fluidized and mixed for 5 minutes. Next, 2.5 g of HMDS (hexamethylene disilazane) (product name “TSL-8802” manufactured by Momentive Performance Materials Japan GK) was sprayed and mixed by fluidization for 30 minutes. The hydrophobicity of the obtained hydrophobic spherical silica fine powder was measured by methanol titration method. The hydrophobicity of the non-conductive inorganic particles in Example 13 was 50%.
  • HMDS hexamethylene disil
  • Example 15 Instead of (Step b) of Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film were produced in the same manner as Example 1 except that non-conductive inorganic particles were produced by the method shown below. The connection structure was manufactured, and the conductive particles and the connection structure were evaluated. The results are shown in Table 3-1, Table 3-2 and Table 7-2.
  • Example 15 first, vapor phase hydrophilic spherical silica powder having an average particle diameter of 100 nm was used, and 100 g of spherical silica powder was mixed with a vibrating fluidized bed apparatus (trade name “Vibrated Fluidized Bed Apparatus VUA-15, manufactured by Chuo Kako Co., Ltd.). Type "). Next, 3.0 g of water was sprayed while fluidizing the spherical silica with air circulated by a suction blower and fluidized and mixed for 5 minutes. Next, 5.0 g of HMDS (hexamethylene disilazane) (product name “TSL-8802” manufactured by Momentive Performance Materials Japan GK) was sprayed and mixed by fluidization for 30 minutes. The hydrophobicity of the obtained hydrophobic spherical silica fine powder was measured by methanol titration method. The hydrophobicity of the nonconductive inorganic particles in Example 13 was 80%.
  • Example 16> instead of (Step b) of Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film were produced in the same manner as Example 1 except that non-conductive inorganic particles were produced by the method shown below.
  • the connection structure was manufactured, and the conductive particles and the connection structure were evaluated. The results are shown in Table 3-1, Table 3-2 and Table 7-2.
  • Example 16 first, vapor phase hydrophilic spherical silica powder having an average particle diameter of 100 nm was used, and 100 g of spherical silica powder was mixed with a vibrating fluidized bed apparatus (trade name “Vibrated Fluidized Bed Apparatus VUA-15, manufactured by Chuo Kako Co., Ltd.). Type "). Next, 3.0 g of water was sprayed while fluidizing the spherical silica with air circulated by a suction blower and fluidized and mixed for 5 minutes.
  • a vibrating fluidized bed apparatus trade name “Vibrated Fluidized Bed Apparatus VUA-15, manufactured by Chuo Kako Co., Ltd.
  • HMDS hexamethylene disilazane
  • TSL-8802 Momentive Performance Materials Japan LLC
  • Example 17 Conductive particles and insulating coated conductive particles in the same manner as in Example 1 except that 0.04 g was used instead of 0.05 g of the spherical silica powder hydrophobized by HMDS in (Step c) of Example 1.
  • 0.04 g was used instead of 0.05 g of the spherical silica powder hydrophobized by HMDS in (Step c) of Example 1.
  • the production of anisotropic conductive adhesive films and connection structures, and the evaluation of conductive particles and connection structures were performed. The results are shown in Table 3-1, Table 3-2 and Table 7-2.
  • Example 18 Conductive particles and insulating coated conductive particles in the same manner as in Example 1 except that 0.03 g was used instead of 0.05 g of the spherical silica powder hydrophobized by HMDS in (Step c) of Example 1.
  • 0.03 g was used instead of 0.05 g of the spherical silica powder hydrophobized by HMDS in (Step c) of Example 1.
  • the production of anisotropic conductive adhesive films and connection structures, and the evaluation of conductive particles and connection structures were performed. The results are shown in Table 3-1, Table 3-2 and Table 7-2.
  • Example 19 In the same manner as in Example 1 except that 3 g of 30% by weight polyethyleneimine aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) having an average molecular weight of 600 was used instead of 3 g of the polyethyleneimine aqueous solution in (Step a) of Example 1.
  • the conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 3-3, Table 3-4 and Table 8-1.
  • Example 1 (Step a) is the same as Example 1 except that in place of 3 g of the polyethyleneimine aqueous solution, 3 g of a 30% by weight polyethyleneimine aqueous solution having an average molecular weight of 10,000 (manufactured by Wako Pure Chemical Industries, Ltd.) Then, production of conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film and connection structure, and evaluation of conductive particles and connection structure were performed. The results are shown in Table 3-3, Table 3-4 and Table 8-1.
  • Example 21 In the same manner as in Example 1 except that the polydimethylsiloxane (PDMS) (manufactured by Wako Pure Chemical Industries, Ltd.) 2.5 g was used instead of HMDS 2.5 g in (Step b) of Example 1, Production of particles, insulating coated conductive particles, anisotropic conductive adhesive film and connection structure, and evaluation of conductive particles and connection structure were performed. The results are shown in Table 3-3, Table 3-4 and Table 8-1.
  • PDMS polydimethylsiloxane
  • Example 1 is different from Example 1 (step b) except that 2.5 g of N, N-dimethylaminotrimethylsilane (DMATMS) (manufactured by Wako Pure Chemical Industries, Ltd.) is used instead of 2.5 g of HMDS.
  • DMATMS N, N-dimethylaminotrimethylsilane
  • production of conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film and connection structure, and evaluation of conductive particles and connection structure were performed. The results are shown in Table 4-1, Table 4-2, and Table 8-1.
  • Example 23 Except that (Step e) in Example 1 was omitted and that the first layer b was formed by the following method instead of (Step f) in Example 1, the same procedure as in Example 1 was performed.
  • the conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 4-1, Table 4-2 and Table 8-2.
  • Example 23 first, the amount of the electroless nickel plating solution for forming the first layer b was 100 ml, and a first layer b consisting of a nickel-phosphorus alloy film having a thickness of 100 nm was formed.
  • the particle D obtained by forming the b layer of the first layer was 4.55 g.
  • Example 24 In the same manner as in Example 1 except that the first layer a and b were formed by the following method instead of (Step e) and (Step f) in Example 1, conductive particles and insulating coatings were formed. Production of conductive particles, anisotropic conductive adhesive films and connection structures, and evaluation of conductive particles and connection structures were performed. The results are shown in Table 4-1, Table 4-2 and Table 8-2.
  • step d After the particle B dispersion obtained in step d was diluted with 1000 mL of water heated to 80 ° C., 1 mL of a 1 g / L bismuth nitrate aqueous solution was added as a plating stabilizer. Next, 20 mL of electroless nickel plating solution for forming a layer having the following composition was dropped into the particle B dispersion at a dropping rate of 5 mL / min.
  • the composition of the electroless nickel plating solution for forming the first layer a is as follows. Nickel sulfate ... 400g / L Sodium hypophosphite ... 150g / L Acetic acid ... 120g / L Bismuth nitrate aqueous solution (1 g / L) ... 1 mL / L
  • a b-layer forming plating solution having the following composition was added dropwise at a dropping rate of 5 mL / min. After 10 minutes had elapsed after the completion of the dropping, the dispersion with the plating solution added was filtered. The filtrate was washed with water and then dried with a vacuum dryer at 80 ° C. In this way, a first layer composed of a nickel-phosphorus alloy film having a thickness of 20 nm for the first layer shown in Table 4-1 and a thickness of 80 nm for the first layer b was formed.
  • the particle D obtained by forming the first layer a and b was 4.55 g.
  • Nickel sulfate 400g / L Sodium hypophosphite ... 150g / L Sodium tartrate dihydrate ... 60g / L Bismuth nitrate aqueous solution (1 g / L) ... 1 mL / L
  • Example 24 the nickel concentration in the a layer was 93.0% by mass (remaining phosphorus), and the nickel concentration in the b layer gradually increased toward the surface of the conductive particles.
  • the concentration of nickel on the surface of the b layer was 97.5% by mass (remaining phosphorus).
  • Example 25 4.55 g of the particles D produced through (Step a) to (Step f) in Example 1 were immersed in 1 L (pH: 6) of an electroless palladium plating solution having the following composition to form a second layer.
  • the reaction time was 10 minutes and the temperature was 50 ° C.
  • the average thickness of the second layer was 10 nm, and the palladium content in the second layer was 100% by mass.
  • the insulation coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced in the same manner as in Example 1, and the conductive particles and the connection structure were evaluated.
  • the results are shown in Table 4-3, Table 4-4 and Table 8-2.
  • the composition of the electroless palladium plating solution is as follows. Palladium chloride ... 0.07g / L EDTA ⁇ 2 sodium ⁇ ⁇ ⁇ 1g / L Citric acid ⁇ disodium ⁇ ⁇ ⁇ 1g / L Sodium formate ... 0.2g / L
  • Example 26 4.55 g of the particles D produced through (Step a to Step f) of Example 1 were added to 1 L of a solution of a substitution gold plating solution (trade name “HGS-100”, manufactured by Hitachi Chemical Co., Ltd.) at 85 ° C. at 85 ° C. For 2 minutes and then washed with water for 2 minutes to form a second layer. The reaction time was 10 minutes and the temperature was 60 ° C. The average thickness of the second layer was 10 nm, and the gold content in the second layer was approximately 100% by mass. Except for using these conductive particles, the insulation coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced in the same manner as in Example 1, and the conductive particles and the connection structure were evaluated. The results are shown in Table 4-3, Table 4-4 and Table 8-2.
  • Step a of Example 1 was performed.
  • a colloidal silica dispersion having an average particle diameter of 100 nm was diluted with ultrapure water to obtain a 0.33% by mass silica particle dispersion (total amount of silica: 0.05 g).
  • Resin particles adsorbed with the polyethyleneimine prepared in (Step a) were added to the dispersion and stirred at room temperature for 15 minutes. Thereafter, the resin particles were taken out by filtration using a ⁇ 3 ⁇ m membrane filter (manufactured by Merck Millipore). Since silica was not extracted from the filtrate, it was confirmed that substantially all silica particles were adsorbed on the resin particles.
  • Resin particles adsorbed with silica particles were placed in 200 g of ultrapure water and stirred at room temperature for 5 minutes. Thereafter, resin particles were taken out by filtration using a ⁇ 3 ⁇ m membrane filter (manufactured by Merck Millipore), and the resin particles on the membrane filter were washed twice with 200 g of ultrapure water. The washed resin particles were dried by heating at 80 ° C. for 30 minutes and 120 ° C. for 1 hour in order to obtain 2.05 g of resin particles having silica particles adsorbed on the surface.
  • a palladium catalyst containing 8% by mass of a palladium catalyst manufactured by Atotech Japan Co., Ltd., trade name “Atotech Neogant 834”.
  • the solution was added to 100 mL of the chemical solution and stirred at 30 ° C. for 30 minutes while irradiating with ultrasonic waves. Thereafter, the resin particles were removed by filtration using a ⁇ 3 ⁇ m membrane filter (manufactured by Merck Millipore), and the removed resin particles were washed with water.
  • the resin particles after washing with water were added to a 0.5 mass% dimethylamine borane solution adjusted to pH 6.0 to obtain 2.01 g of resin particles to which a palladium catalyst was fixed. Then, 2.01 g of resin particles having a palladium catalyst fixed thereon were immersed in 20 mL of distilled water, and then ultrasonically dispersed to obtain a resin particle dispersion. The result of observing the particles after ultrasonic dispersion by SEM is shown in FIG.
  • Step a of Example 1 was performed.
  • 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 100 nm as in Example 5 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • Resin particles on which silica was adsorbed were obtained.
  • the amount of resin particles on which silica was adsorbed was 2.05 g.
  • a palladium catalyst containing 8% by mass of a palladium catalyst manufactured by Atotech Japan Co., Ltd., trade name “Atotech Neogant 834”.
  • the solution was added to 100 mL of the chemical solution and stirred at 30 ° C. for 30 minutes while irradiating with ultrasonic waves. Thereafter, the resin particles were removed by filtration using a ⁇ 3 ⁇ m membrane filter (manufactured by Merck Millipore), and the removed resin particles were washed with water.
  • the resin particles after washing with water were added to a 0.5 mass% dimethylamine borane solution adjusted to pH 6.0 to obtain 2.01 g of resin particles to which a palladium catalyst was fixed. Then, 2.01 g of resin particles having a palladium catalyst fixed thereon were immersed in 20 mL of distilled water, and then ultrasonically dispersed to obtain a resin particle dispersion.
  • Step a of Example 1 was performed.
  • 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 25 nm as in Example 2 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • Resin particles on which silica was adsorbed were obtained.
  • the amount of resin particles on which silica was adsorbed was 2.05 g.
  • Step a of Example 1 was performed.
  • 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 60 nm as in Example 1 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • Resin particles on which silica was adsorbed were obtained.
  • the amount of resin particles on which silica was adsorbed was 2.05 g.
  • Step a of Example 1 was performed.
  • 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 100 nm as in Example 5 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • Resin particles on which silica was adsorbed were obtained.
  • the amount of resin particles on which silica was adsorbed was 2.05 g.
  • Step a of Example 1 was performed.
  • 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 120 nm as in Example 6 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W.
  • Resin particles on which silica was adsorbed were obtained.
  • the amount of resin particles on which silica was adsorbed was 2.05 g.
  • ⁇ Comparative Example 7> Cross-linked polystyrene particles having an average particle size of 3.0 ⁇ m (trade name “Soliostar” manufactured by Nippon Shokubai Co., Ltd.) were used as resin particles. While stirring 400 mL of the cleaner conditioner 231 aqueous solution (Rohm and Haas Electronic Materials Co., Ltd., concentration: 40 mL / L), 30 g of resin particles were added thereto. Subsequently, the aqueous solution was heated to 60 ° C. and stirred for 30 minutes while applying ultrasonic waves to perform surface modification and dispersion treatment of the resin particles.
  • the aqueous solution was filtered and the obtained particles were washed once with water, and then 30 g of the particles were dispersed in water to obtain 200 mL of slurry.
  • 200 mL of stannous chloride aqueous solution (concentration: 1.5 g / L) was added and stirred for 5 minutes at room temperature to perform sensitization treatment for adsorbing tin ions on the surface of the particles.
  • the aqueous solution was filtered, and the resulting particles were washed once with water.
  • 30 g of particles were dispersed in water to prepare a 400 mL slurry, and then heated to 60 ° C.
  • electroless plating solution composed of an aqueous solution in which 20 g / L sodium tartrate, 10 g / L nickel sulfate and 0.5 g / L sodium hypophosphite were dissolved was heated to 60 ° C.
  • the electroless plating solution was charged with 10 g of the particles. This was stirred for 5 minutes, and it was confirmed that hydrogen foaming stopped.
  • a 200 g / L nickel sulfate aqueous solution (400 mL) and a 200 g / L sodium hypophosphite and 90 g / L sodium hydroxide mixed aqueous solution (400 mL) were each simultaneously and continuously converted into a plating solution containing particles by a metering pump. Added. The addition rate was 3 mL / min. The solution was then stirred for 5 minutes while maintaining the temperature at 60 ° C., and then the solution was filtered. The filtrate was washed three times and then dried with a vacuum dryer at 100 ° C. to obtain conductive particles having a nickel-phosphorus alloy coating.
  • the cross section was cut out by the ultra microtome method so that it might pass through center vicinity of particle
  • the average film thickness of the nickel-phosphorus alloy film was 105 nm.
  • Example 1 The production of the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure, and the evaluation of the connection structure were performed in the same manner as in Example 1 except that this conductive particle was used. Regarding the evaluation of the conductive particles, a part of the evaluation was performed in the same manner as in Example 1. The results are shown in Table 5-3, Table 5-4 and Table 9-2.
  • ⁇ Comparative Example 8> Cross-linked polystyrene particles having an average particle size of 3.0 ⁇ m (trade name “Soliostar” manufactured by Nippon Shokubai Co., Ltd.) were used as resin particles. While stirring 400 mL of the cleaner conditioner 231 aqueous solution (Rohm and Haas Electronic Materials Co., Ltd., concentration: 40 mL / L), 7 g of resin particles were added thereto. Subsequently, the aqueous solution was heated to 60 ° C. and stirred for 30 minutes while applying ultrasonic waves to perform surface modification and dispersion treatment of the resin particles.
  • the aqueous solution was filtered, and the obtained particles were washed once, and then 7 g of the particles were dispersed in pure water to obtain 200 mL of slurry.
  • 200 mL of stannous chloride aqueous solution (concentration: 1.5 g / L) was added and stirred for 5 minutes at room temperature to perform sensitization treatment for adsorbing tin ions on the surface of the particles.
  • the aqueous solution was filtered, and the resulting particles were washed once with water.
  • 7 g of particles were dispersed in water to prepare a 400 mL slurry, and then heated to 60 ° C.
  • the dispersion was further diluted with 1200 mL of water, and 4 mL of a bismuth nitrate aqueous solution (concentration 1 g / L) was added as a plating stabilizer.
  • a bismuth nitrate aqueous solution concentration 1 g / L
  • 120 mL of a mixed solution of nickel sulfate 450 g / L, sodium hypophosphite 150 g / L, sodium citrate 116 g / L, and plating stabilizer (bismuth nitrate aqueous solution (concentration 1 g / L)) 6 mL was added to this dispersion.
  • the addition was made through a metering pump at an addition rate of 81 mL / min. Then, it stirred until pH became stable and it confirmed that foaming of hydrogen stopped.
  • an addition rate of 650 mL of a mixed solution of nickel sulfate 450 g / L, sodium hypophosphite 150 g / L, sodium citrate 116 g / L, and 35 mL of a plating stabilizer (bismuth nitrate aqueous solution (concentration 1 g / L)) is 27 mL / min.
  • a plating stabilizer bismuth nitrate aqueous solution (concentration 1 g / L)
  • the plating solution was filtered, and the filtrate was washed with water. Thereafter, the particles were dried with a vacuum dryer at 80 ° C. to obtain conductive particles having a nickel-phosphorus alloy coating.
  • the cross section was cut out by the ultra microtome method so that it might pass through center vicinity of particle
  • the average film thickness of the nickel-phosphorus alloy coating was 101 nm.
  • Example 1 The production of the insulation coated conductive particles, the anisotropic conductive adhesive film and the connection structure, and the evaluation of the connection structure were performed in the same manner as in Example 1 except that the conductive particles were used. Regarding the evaluation of the conductive particles, a part of the evaluation was performed in the same manner as in Example 1. The results are shown in Table 5-3, Table 5-4 and Table 9-2.
  • Comparative Example 1 corresponds to the conductive particles of Patent Document 3 above.
  • the conductive particles of Comparative Example 7 correspond to the conductive particles of Patent Document 1.
  • the conductive particles of Comparative Example 8 correspond to the conductive particles of Patent Document 2.

Abstract

Provided are conductive particles which enable the achievement of a good balance between excellent conduction reliability and insulation reliability in cases where the conductive particles are blended in an anisotropic conductive adhesive. Each conductive particle 100a comprises: a composite particle 103 that has a resin particle 101, which is coated with a cationic polymer, and non-conductive inorganic particles 102, which are arranged on the surface of the resin particle 101; and a metal layer that covers the composite particle 103. The non-conductive inorganic particles 102 are coated with a hydrophobilizing agent.

Description

導電粒子、絶縁被覆導電粒子、異方導電性接着剤、接続構造体及び導電粒子の製造方法Conductive particle, insulating coated conductive particle, anisotropic conductive adhesive, connection structure, and method for producing conductive particle
　本発明は、導電粒子、絶縁被覆導電粒子、異方導電性接着剤、接続構造体及び導電粒子の製造方法に関する。 The present invention relates to a conductive particle, an insulating coated conductive particle, an anisotropic conductive adhesive, a connection structure, and a method for manufacturing the conductive particle.
　液晶表示用ガラスパネルに液晶駆動用ＩＣを実装する方式は、ＣＯＧ（Ｃｈｉｐ－ｏｎ－Ｇｌａｓｓ）実装及びＣＯＦ（Ｃｈｉｐ－ｏｎ－Ｆｌｅｘ）実装の二種に大別することができる。ＣＯＧ実装では、導電粒子を含む異方導電性接着剤を用いて液晶駆動用ＩＣをガラスパネル上に直接接合する。一方、ＣＯＦ実装では、金属配線を有するフレキシブルテープに液晶駆動用ＩＣを接合し、導電粒子を含む異方導電性接着剤を用いてそれらをガラスパネルに接合する。ここでいう「異方性」とは、加圧方向には導通し、非加圧方向では絶縁性を保つという意味である。 The method of mounting a liquid crystal driving IC on a glass panel for liquid crystal display can be roughly divided into two types: COG (Chip-on-Glass) mounting and COF (Chip-on-Flex) mounting. In COG mounting, a liquid crystal driving IC is directly bonded onto a glass panel using an anisotropic conductive adhesive containing conductive particles. On the other hand, in COF mounting, a liquid crystal driving IC is bonded to a flexible tape having metal wiring, and these are bonded to a glass panel using an anisotropic conductive adhesive containing conductive particles. The term “anisotropic” as used herein means that conduction is achieved in the pressurizing direction and insulation is maintained in the non-pressurizing direction.
　従来、導電粒子としては、表面に金層を有する導電粒子が用いられてきた。表面に金層を有する導電粒子は、電気抵抗値が低い点で有利である。金は酸化されにくいため、表面に金層を有する導電粒子を長期間保存した場合であっても、当該導電粒子の電気抵抗値が高くなることを抑制できる。 Conventionally, conductive particles having a gold layer on the surface have been used as the conductive particles. Conductive particles having a gold layer on the surface are advantageous in that they have a low electrical resistance value. Since gold is not easily oxidized, even when conductive particles having a gold layer on the surface are stored for a long period of time, an increase in the electrical resistance value of the conductive particles can be suppressed.
　近年、省エネルギー化に対応して、液晶駆動時の消費電力を抑えるために、液晶駆動用ＩＣに流れる電流量の低減が検討されている。そのため、従来よりも更に低い電気抵抗値を達成可能な導電粒子が求められている。近年、貴金属の価格が高騰しているため、貴金属を使用しない導電粒子を用いて電気抵抗値を低くすることが求められている。 In recent years, reduction of the amount of current flowing through a liquid crystal driving IC has been studied in order to reduce power consumption during liquid crystal driving in response to energy saving. Therefore, there is a demand for conductive particles that can achieve a lower electrical resistance value than before. In recent years, since the price of noble metals has risen, it has been required to reduce the electrical resistance value using conductive particles that do not use noble metals.
　例えば、下記特許文献１～３には、貴金属を使用することなく、ニッケルのみを使用して低い電気抵抗値を有する導電粒子が開示されている。具体的には、特許文献１には、無電解ニッケルめっき法におけるニッケルめっき液の自己分解を利用して、非導電粒子にニッケルの微小突起とニッケル被膜とを同時に形成させ、表面に導電性の突起を有する導電粒子を製造する方法が記載されている。特許文献２には、基材微粒子の表面に芯物質となる導電性物質を付着させた後、当該基材微粒子に無電解ニッケルめっきを行うことで、表面に導電性の突起を有する導電粒子を製造する方法が記載されている。特許文献３には、基材微粒子の表面に芯物質となる非導電性物質を化学結合により吸着させた後、当該基材微粒子に無電解ニッケルめっきを行うことで、表面に導電性の突起を有する導電粒子を製造する方法が記載されている。 For example, the following Patent Documents 1 to 3 disclose conductive particles having a low electric resistance value using only nickel without using a noble metal. Specifically, in Patent Document 1, by utilizing the self-decomposition of a nickel plating solution in an electroless nickel plating method, a nickel microprojection and a nickel coating are simultaneously formed on non-conductive particles, and the surface is made conductive. A method for producing conductive particles having protrusions is described. In Patent Document 2, conductive particles having conductive protrusions on the surface are obtained by attaching an electroconductive substance serving as a core substance to the surface of the base particle, and then performing electroless nickel plating on the base particle. A method of manufacturing is described. In Patent Document 3, a non-conductive substance serving as a core substance is adsorbed on the surface of the base particle by chemical bonding, and then electroless nickel plating is performed on the base particle, thereby forming a conductive protrusion on the surface. A method for producing conductive particles is described.
特許第５１８４６１２号公報Japanese Patent No. 5184612 特許第４６７４０９６号公報Japanese Patent No. 4674096 特許第４６４０５３１号公報Japanese Patent No. 4640531
　異方導電性接着剤によりチップを実装する場合、接続する電極間の導通抵抗を低くし、なおかつ、チップにおける隣接する電極間の絶縁抵抗を充分高くする必要がある。近年、電極のパッド面積が小さくなってきており、電極間に捕捉される粒子の個数が少なくなってきているために、粒子一つ一つの導通抵抗を均一に低くすることが求められる。上記特許文献１～３に記載の導電粒子を配合した異方導電性接着剤を用いた接続構造体は、接続初期においては充分な接続抵抗値を示す。しかしながら、これらの接続構造体を高温高湿下で保存した場合、接続抵抗値が上昇してしまうことがある。さらに、上記特許文献１～３に記載の導電粒子を配合した異方導電性接着剤を用いた接続構造体においては、接続初期では充分な絶縁抵抗値が示されるが、高温高湿下で長期間導通を行うマイグレーション試験後では絶縁抵抗値が低下することがある。 When a chip is mounted with an anisotropic conductive adhesive, it is necessary to lower the conduction resistance between the electrodes to be connected and sufficiently increase the insulation resistance between adjacent electrodes in the chip. In recent years, the pad area of the electrodes has been reduced, and the number of particles trapped between the electrodes has been reduced, so that it is required to uniformly reduce the conduction resistance of each particle. The connection structure using the anisotropic conductive adhesive containing the conductive particles described in Patent Documents 1 to 3 shows a sufficient connection resistance value at the initial connection stage. However, when these connection structures are stored under high temperature and high humidity, the connection resistance value may increase. Further, in the connection structure using the anisotropic conductive adhesive containing the conductive particles described in Patent Documents 1 to 3, a sufficient insulation resistance value is shown at the initial connection stage, but the connection structure is long under high temperature and high humidity. The insulation resistance value may decrease after a migration test in which conduction is performed for a period.
　本発明の一側面は、異方導電性接着剤に配合される導電粒子として用いられたときに優れた導通信頼性及び絶縁信頼性を両立することができる導電粒子及びその製造方法を提供することを目的とする。また、本発明の一側面は、前記導電粒子を用いた絶縁被覆導電粒子、異方導電性接着剤及び接続構造体を提供することを目的とする。 One aspect of the present invention is to provide conductive particles capable of achieving both excellent conduction reliability and insulation reliability when used as conductive particles blended in an anisotropic conductive adhesive, and a method for producing the same. With the goal. Another object of the present invention is to provide insulating coated conductive particles, anisotropic conductive adhesives, and connection structures using the conductive particles.
　本発明の一態様に係る導電粒子は、カチオン性ポリマーにより被覆された樹脂粒子、及び樹脂粒子の表面に配置される非導電性無機粒子を有する複合粒子と、複合粒子を覆う金属層と、を備え、非導電性無機粒子は、疎水化処理剤によって被覆されている。 Conductive particles according to one embodiment of the present invention include resin particles coated with a cationic polymer, composite particles having non-conductive inorganic particles disposed on the surfaces of the resin particles, and a metal layer covering the composite particles. The non-conductive inorganic particles are coated with a hydrophobizing agent.
　この導電粒子によれば、樹脂粒子はカチオン性ポリマーにより被覆され、非導電性無機粒子は疎水化処理剤によって被覆される。非導電性無機粒子の表面のゼータ電位は、疎水化によりマイナスにシフトする。これにより、樹脂粒子と非導電性無機粒子との間には静電気力が働き、樹脂粒子の表面から非導電性無機粒子が脱落しにくくなる。このため、樹脂粒子の表面に配置される非導電性無機粒子の数の制御が容易になると共に、複合粒子に良好な突起が形成される。したがって、導電粒子が配合された異方導電性接着剤を用いた接続構造体を高温高湿下に保存した場合であっても、導通信頼性が向上する。加えて、樹脂粒子から脱落する非導電性無機粒子の数が低減されるので、複合粒子に異常に成長した突起が発生しにくくなる。このため、導電粒子が異方導電性接着剤に配合された場合等に当該導電粒子同士が導通しにくくなり、導電粒子の絶縁信頼性も向上する。したがって、上記導電粒子を異方導電性接着剤に配合することによって、優れた導通信頼性及び絶縁信頼性を両立することができる。 According to the conductive particles, the resin particles are coated with the cationic polymer, and the non-conductive inorganic particles are coated with the hydrophobic treatment agent. The zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity. Thereby, an electrostatic force acts between the resin particles and the non-conductive inorganic particles, and the non-conductive inorganic particles are not easily dropped from the surface of the resin particles. For this reason, it becomes easy to control the number of non-conductive inorganic particles arranged on the surface of the resin particles, and good protrusions are formed on the composite particles. Therefore, even when the connection structure using the anisotropic conductive adhesive containing conductive particles is stored under high temperature and high humidity, conduction reliability is improved. In addition, since the number of non-conductive inorganic particles falling off from the resin particles is reduced, abnormally grown protrusions are hardly generated on the composite particles. For this reason, when the conductive particles are blended in the anisotropic conductive adhesive, the conductive particles are less likely to conduct with each other, and the insulation reliability of the conductive particles is improved. Therefore, excellent conduction reliability and insulation reliability can be achieved by blending the conductive particles with the anisotropic conductive adhesive.
　疎水化処理剤は、シラザン系疎水化処理剤、シロキサン系疎水化処理剤、シラン系疎水化処理剤、及びチタネート系疎水化処理剤からなる群より選ばれてもよい。 The hydrophobizing agent may be selected from the group consisting of a silazane hydrophobizing agent, a siloxane hydrophobizing agent, a silane hydrophobizing agent, and a titanate hydrophobizing agent.
　疎水化処理剤は、ヘキサメチレンジシラザン、ポリジメチルシロキサン、及びＮ，Ｎ－ジメチルアミノトリメチルシランからなる群より選ばれてもよい。 The hydrophobizing agent may be selected from the group consisting of hexamethylene disilazane, polydimethylsiloxane, and N, N-dimethylaminotrimethylsilane.
　メタノール滴定法による非導電性無機粒子の疎水化度は、３０％以上であってもよい。この場合、非導電性無機粒子と樹脂粒子との間に十分な静電気力が働く。 The hydrophobicity of the non-conductive inorganic particles by methanol titration method may be 30% or more. In this case, a sufficient electrostatic force acts between the non-conductive inorganic particles and the resin particles.
　非導電性無機粒子は、静電気力によって樹脂粒子に接着されていてもよい。 Non-conductive inorganic particles may be adhered to resin particles by electrostatic force.
　樹脂粒子と非導電性無機粒子とのゼータ電位の差は、ｐＨ１以上ｐＨ１１以下において３０ｍＶ以上であってもよい。この場合、樹脂粒子と非導電性無機粒子とが静電気力により強固に接着する。したがって、導電粒子における金属層を形成するための前処理工程、金属層の形成工程等の際に、樹脂粒子から非導電性無機粒子が脱落することを好適に抑制できる。 The difference in zeta potential between the resin particles and the non-conductive inorganic particles may be 30 mV or more at pH 1 or more and pH 11 or less. In this case, the resin particles and the non-conductive inorganic particles are firmly bonded by electrostatic force. Therefore, it is possible to suitably suppress the nonconductive inorganic particles from dropping from the resin particles during the pretreatment step for forming the metal layer in the conductive particles, the metal layer forming step, and the like.
　カチオン性ポリマーは、ポリアミン、ポリイミン、ポリアミド、ポリジアリルジメチルアンモニウムクロリド、ポリビニルアミン、ポリビニルピリジン、ポリビニルイミダゾール及びポリビニルピロリドンからなる群より選ばれてもよい。 The cationic polymer may be selected from the group consisting of polyamine, polyimine, polyamide, polydiallyldimethylammonium chloride, polyvinylamine, polyvinylpyridine, polyvinylimidazole, and polyvinylpyrrolidone.
　カチオン性ポリマーは、ポリエチレンイミンであってもよい。この場合、カチオン性ポリマーの電荷密度が高くなるので、非導電性無機粒子の脱落を良好に抑制できる。 The cationic polymer may be polyethyleneimine. In this case, since the charge density of the cationic polymer is increased, it is possible to favorably suppress the non-conductive inorganic particles from falling off.
　非導電性無機粒子の平均粒径は、２５ｎｍ以上１２０ｎｍ以下であってもよい。この場合、導電粒子は緻密な突起を多数有することができると共に、非導電性無機粒子が樹脂粒子から脱落しにくくなる。 The average particle diameter of the non-conductive inorganic particles may be 25 nm or more and 120 nm or less. In this case, the conductive particles can have a large number of dense protrusions, and the non-conductive inorganic particles are difficult to drop off from the resin particles.
　樹脂粒子の平均粒径は、１μｍ以上１０μｍ以下であってもよい。この場合、例えば、導電粒子を含む異方導電性接着剤を用いて接続構造体を作製した際に、当該接続構造体の電極の形状（高さ）のばらつきによって、当該異方導電性接着剤の導電性等が変化しにくくなる。 The average particle diameter of the resin particles may be 1 μm or more and 10 μm or less. In this case, for example, when a connection structure is produced using an anisotropic conductive adhesive containing conductive particles, the anisotropic conductive adhesive may vary depending on the shape (height) of the electrodes of the connection structure. It becomes difficult for the conductivity etc. of this to change.
　非導電性無機粒子は、シリカ、ジルコニア、アルミナ、及びダイヤモンドからなる群より選ばれてもよい。 The non-conductive inorganic particles may be selected from the group consisting of silica, zirconia, alumina, and diamond.
　金属層は、ニッケルを含有する第１層を有してもよい。この場合、導電粒子の硬度を高めることができる。これにより、当該導電粒子が圧縮された場合であっても非導電性無機粒子上に形成されて突起部分となった第１層は、押し潰されにくくなる。したがって、導電粒子は、低い導通抵抗を得ることができる。 The metal layer may have a first layer containing nickel. In this case, the hardness of the conductive particles can be increased. Thereby, even when the conductive particles are compressed, the first layer formed on the non-conductive inorganic particles and serving as a protruding portion is not easily crushed. Therefore, the conductive particles can obtain a low conduction resistance.
　金属層は、第１層上に設けられる第２層を有し、第２層は、貴金属及びコバルトからなる群より選ばれる金属を含有してもよい。この場合、導電粒子は、一層低い導通抵抗を得ることができる。 The metal layer may have a second layer provided on the first layer, and the second layer may contain a metal selected from the group consisting of noble metals and cobalt. In this case, the conductive particles can obtain a lower conduction resistance.
　本発明の他の一態様に係る絶縁被覆導電粒子は、上記導電粒子と、当該導電粒子の金属層の外表面の少なくとも一部を被覆する絶縁性被覆部と、を備える。 An insulating coated conductive particle according to another aspect of the present invention includes the conductive particle and an insulating coating portion that covers at least a part of the outer surface of the metal layer of the conductive particle.
　この絶縁被覆導電粒子によれば、樹脂粒子はカチオン性ポリマーにより被覆され、非導電性無機粒子は疎水化処理剤によって被覆される。非導電性無機粒子の表面のゼータ電位は、疎水化によりマイナスにシフトする。これにより、樹脂粒子と非導電性無機粒子との間には静電気力が働き、樹脂粒子の表面から非導電性無機粒子が脱落しにくくなる。このため、樹脂粒子の表面に配置される非導電性無機粒子の数の制御が容易になると共に、複合粒子に良好な突起が形成される。したがって、導電粒子が配合された異方導電性接着剤を用いた接続構造体を高温高湿下に保存した場合であっても、導通信頼性が向上する。加えて、樹脂粒子から脱落する非導電性無機粒子の数が低減されるので、複合粒子に異常に成長した突起が発生しにくくなる。さらには、金属層の外表面に設けられた絶縁性被覆部により、絶縁被覆導電粒子の金属層同士が接触しにくくなる。これにより、絶縁被覆導電粒子が異方導電性接着剤に配合された場合等に絶縁被覆導電粒子同士が導通しにくくなり、当該絶縁被覆導電粒子を用いた接続構造体等の絶縁信頼性も好適に向上する。したがって、上記導電粒子を異方導電性接着剤に配合することによって、優れた導通信頼性及び絶縁信頼性を両立することができる。 According to the insulating coated conductive particles, the resin particles are coated with the cationic polymer, and the nonconductive inorganic particles are coated with the hydrophobizing agent. The zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity. Thereby, an electrostatic force acts between the resin particles and the non-conductive inorganic particles, and the non-conductive inorganic particles are not easily dropped from the surface of the resin particles. For this reason, it becomes easy to control the number of non-conductive inorganic particles arranged on the surface of the resin particles, and good protrusions are formed on the composite particles. Therefore, even when the connection structure using the anisotropic conductive adhesive containing conductive particles is stored under high temperature and high humidity, conduction reliability is improved. In addition, since the number of non-conductive inorganic particles falling off from the resin particles is reduced, abnormally grown protrusions are hardly generated on the composite particles. Furthermore, the insulating coating portions provided on the outer surface of the metal layer make it difficult for the metal layers of the insulating coated conductive particles to come into contact with each other. As a result, when the insulating coating conductive particles are blended in the anisotropic conductive adhesive, the insulating coating conductive particles are difficult to conduct with each other, and the insulation reliability of the connection structure using the insulating coating conductive particles is also suitable. To improve. Therefore, excellent conduction reliability and insulation reliability can be achieved by blending the conductive particles with the anisotropic conductive adhesive.
　本発明の他の一態様に係る接続構造体は、第１回路電極を有する第１回路部材と、第１回路部材に対向し、第２回路電極を有する第２回路部材と、第１回路部材及び第２回路部材の間に配置され、上記導電粒子を含有する接続部と、を備え、接続部は、第１回路電極と第２回路電極とが対向するように配置された状態で第１回路部材及び第２回路部材を互いに接続し、第１回路電極と第２回路電極とは、変形した状態の導電粒子を介して互いに電気的に接続される。 A connection structure according to another aspect of the present invention includes a first circuit member having a first circuit electrode, a second circuit member facing the first circuit member and having a second circuit electrode, and a first circuit member. And a connecting portion that is disposed between the second circuit members and contains the conductive particles, and the connecting portion is arranged in such a manner that the first circuit electrode and the second circuit electrode face each other. The circuit member and the second circuit member are connected to each other, and the first circuit electrode and the second circuit electrode are electrically connected to each other through the deformed conductive particles.
　この接続構造体によれば、上記導電粒子が含有された接続部を備えることにより高温高湿下に保存した場合であっても、導通信頼性が向上する。加えて、接続部内にて樹脂粒子から脱落する非導電性無機粒子の数が低減されるので、複合粒子に異常に成長した突起が発生しにくくなる。したがって、接続部内にて導電粒子同士が導通しにくくなり、絶縁信頼性も好適に向上する。したがって、優れた導通信頼性及び絶縁信頼性を両立した接続構造体を提供できる。 According to this connection structure, the connection reliability is improved by providing the connection part containing the conductive particles, even when the connection structure is stored under high temperature and high humidity. In addition, since the number of non-conductive inorganic particles falling off from the resin particles in the connecting portion is reduced, it is difficult for abnormally grown protrusions to be generated on the composite particles. Therefore, it becomes difficult for the conductive particles to conduct in the connection portion, and the insulation reliability is also preferably improved. Therefore, it is possible to provide a connection structure having both excellent conduction reliability and insulation reliability.
　本発明の他の一態様に係る接続構造体は、第１回路電極を有する第１回路部材と、第１回路部材に対向し、第２回路電極を有する第２回路部材と、第１回路部材及び第２回路部材の間に配置され、上記絶縁被覆導電粒子を含有する接続部と、を備え、接続部は、第１回路電極と第２回路電極とが対向するように配置された状態で第１回路部材及び第２回路部材を互いに接続し、第１回路電極と第２回路電極とは、変形した状態の絶縁被覆導電粒子を介して互いに電気的に接続される。 A connection structure according to another aspect of the present invention includes a first circuit member having a first circuit electrode, a second circuit member facing the first circuit member and having a second circuit electrode, and a first circuit member. And a connecting portion that is disposed between the second circuit member and contains the insulating coating conductive particles, and the connecting portion is disposed in such a manner that the first circuit electrode and the second circuit electrode face each other. The first circuit member and the second circuit member are connected to each other, and the first circuit electrode and the second circuit electrode are electrically connected to each other via the insulating coated conductive particles in a deformed state.
　この接続構造体によれば、上記絶縁被覆導電粒子が含有された接続部を備えることにより、高温高湿下に保存した場合であっても、導通信頼性が向上する。加えて、接続部内にて樹脂粒子から脱落する非導電性無機粒子の数が低減されるので、複合粒子に異常に成長した突起が発生しにくくなる。さらには、金属層の外表面に設けられた絶縁性被覆部により、絶縁被覆導電粒子の金属層同士が接触しにくくなる。したがって、接続部内にて絶縁被覆導電粒子同士が導通しにくくなり、絶縁信頼性も好適に向上する。したがって、優れた導通信頼性及び絶縁信頼性を両立した接続構造体を提供できる。 According to this connection structure, by providing the connection portion containing the insulating coating conductive particles, the conduction reliability is improved even when stored under high temperature and high humidity. In addition, since the number of non-conductive inorganic particles falling off from the resin particles in the connecting portion is reduced, it is difficult for abnormally grown protrusions to be generated on the composite particles. Furthermore, the insulating coating portions provided on the outer surface of the metal layer make it difficult for the metal layers of the insulating coated conductive particles to come into contact with each other. Accordingly, it becomes difficult for the insulating coated conductive particles to conduct in the connection portion, and the insulation reliability is also preferably improved. Therefore, it is possible to provide a connection structure having both excellent conduction reliability and insulation reliability.
　本発明の他の一態様に係る異方導電性接着剤は、上記導電粒子と、導電粒子が分散された接着剤と、を備える。 An anisotropic conductive adhesive according to another embodiment of the present invention includes the conductive particles and an adhesive in which the conductive particles are dispersed.
　この異方導電性接着剤によれば、樹脂粒子はカチオン性ポリマーにより被覆され、非導電性無機粒子は疎水化処理剤によって被覆される。非導電性無機粒子の表面のゼータ電位は、疎水化によりマイナスにシフトする。これにより、樹脂粒子と非導電性無機粒子との間には静電気力が働き、樹脂粒子の表面から非導電性無機粒子が脱落しにくくなる。このため、樹脂粒子の表面に配置される非導電性無機粒子の数の制御が容易になると共に、複合粒子に良好な突起が形成される。したがって、当該異方導電性接着剤を用いた接続構造体を高温高湿下に保存した場合であっても、導通信頼性が向上する。加えて、樹脂粒子から脱落する非導電性無機粒子の数が低減されるので、複合粒子に異常に成長した突起が発生しにくくなる。さらには、脱落した非導電性無機粒子が金属によってコーティングされて形成される金属異物は、接着剤中に存在しにくい。したがって、導電粒子同士が良好に導通しにくくなり、当該異方導電性接着剤を用いた接続構造体等の絶縁信頼性も好適に向上する。 According to this anisotropic conductive adhesive, resin particles are coated with a cationic polymer, and non-conductive inorganic particles are coated with a hydrophobizing agent. The zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity. Thereby, an electrostatic force acts between the resin particles and the non-conductive inorganic particles, and the non-conductive inorganic particles are not easily dropped from the surface of the resin particles. For this reason, it becomes easy to control the number of non-conductive inorganic particles arranged on the surface of the resin particles, and good protrusions are formed on the composite particles. Therefore, even when the connection structure using the anisotropic conductive adhesive is stored under high temperature and high humidity, conduction reliability is improved. In addition, since the number of non-conductive inorganic particles falling off from the resin particles is reduced, abnormally grown protrusions are hardly generated on the composite particles. Furthermore, the metal foreign matter formed by coating the dropped non-conductive inorganic particles with a metal is unlikely to exist in the adhesive. Therefore, it becomes difficult for the conductive particles to conduct well, and the insulation reliability of the connection structure using the anisotropic conductive adhesive is also preferably improved.
　本発明の他の一態様に係る異方導電性接着剤は、上記絶縁被覆導電粒子と、絶縁被覆導電粒子が分散された接着剤と、を備える。 An anisotropic conductive adhesive according to another embodiment of the present invention includes the insulating coating conductive particles and an adhesive in which the insulating coating conductive particles are dispersed.
　この異方導電性接着剤によれば、樹脂粒子はカチオン性ポリマーにより被覆され、非導電性無機粒子は疎水化処理剤によって被覆される。非導電性無機粒子の表面のゼータ電位は、疎水化によりマイナスにシフトする。これにより、樹脂粒子と非導電性無機粒子との間には静電気力が働き、樹脂粒子の表面から非導電性無機粒子が脱落しにくくなる。このため、樹脂粒子の表面に配置される非導電性無機粒子の数の制御が容易になると共に、複合粒子に良好な突起が形成される。したがって、当該異方導電性接着剤を用いた接続構造体を高温高湿下に保存した場合であっても、導通信頼性が向上する。また、樹脂粒子から脱落する非導電性無機粒子の数が低減されるので、複合粒子に異常に成長した突起が発生しにくくなる。加えて、金属層の外表面に設けられた絶縁性被覆部により、導電粒子の金属層同士が接触しにくくなる。さらには、脱落した非導電性無機粒子が金属によってコーティングされて形成される金属異物は、接着剤中に存在しにくい。したがって、導電粒子同士が良好に導通しにくくなり、当該導電粒子を用いた接続構造体等の絶縁信頼性も好適に向上する。 According to this anisotropic conductive adhesive, resin particles are coated with a cationic polymer, and non-conductive inorganic particles are coated with a hydrophobizing agent. The zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity. Thereby, an electrostatic force acts between the resin particles and the non-conductive inorganic particles, and the non-conductive inorganic particles are not easily dropped from the surface of the resin particles. For this reason, it becomes easy to control the number of non-conductive inorganic particles arranged on the surface of the resin particles, and good protrusions are formed on the composite particles. Therefore, even when the connection structure using the anisotropic conductive adhesive is stored under high temperature and high humidity, conduction reliability is improved. In addition, since the number of non-conductive inorganic particles falling off from the resin particles is reduced, the abnormally grown protrusions are hardly generated on the composite particles. In addition, the insulating coating provided on the outer surface of the metal layer makes it difficult for the metal layers of the conductive particles to contact each other. Furthermore, the metal foreign matter formed by coating the dropped non-conductive inorganic particles with a metal is unlikely to exist in the adhesive. Therefore, it becomes difficult for the conductive particles to conduct well, and the insulation reliability of the connection structure using the conductive particles is also preferably improved.
　上記異方導電性接着剤において、接着剤がフィルム状であってもよい。 In the anisotropic conductive adhesive, the adhesive may be in the form of a film.
　本発明の他の一態様に係る接続構造体は、第１回路電極を有する第１回路部材と、第１回路部材に対向し、第２回路電極を有する第２回路部材と、第１回路部材及び第２回路部材を接着する、上記異方導電性接着剤と、を備え、第１回路電極と第２回路電極とは、互いに対向すると共に、異方導電性接着剤によって互いに電気的に接続される。 A connection structure according to another aspect of the present invention includes a first circuit member having a first circuit electrode, a second circuit member facing the first circuit member and having a second circuit electrode, and a first circuit member. And the anisotropic conductive adhesive for bonding the second circuit member, the first circuit electrode and the second circuit electrode are opposed to each other and electrically connected to each other by the anisotropic conductive adhesive Is done.
　この接続構造体によれば、上記異方導電性接着剤によって第１回路部材及び第２回路部材が互いに電気的に接続されることにより、優れた導通信頼性及び絶縁信頼性を両立することができる。 According to this connection structure, the first circuit member and the second circuit member are electrically connected to each other by the anisotropic conductive adhesive, thereby achieving both excellent conduction reliability and insulation reliability. it can.
　本発明の他の一態様に係る導電粒子の製造方法は、樹脂粒子をカチオン性ポリマーにより被覆する第１被覆工程と、非導電性無機粒子を疎水化処理剤によって被覆する第２被覆工程と、樹脂粒子の表面に非導電性無機粒子を静電気力により接着し、複合粒子を形成する粒子形成工程と、複合粒子を金属層によって被覆する第３被覆工程と、を備える。 The method for producing conductive particles according to another aspect of the present invention includes a first coating step of coating resin particles with a cationic polymer, and a second coating step of coating non-conductive inorganic particles with a hydrophobic treatment agent, A non-conductive inorganic particle is adhered to the surface of the resin particle by electrostatic force to form a composite particle, and a third coating step of coating the composite particle with a metal layer.
　この製造方法によれば、第１被覆工程にて樹脂粒子はカチオン性ポリマーにより被覆され、第２被覆工程にて非導電性無機粒子は疎水化処理剤によって被覆される。非導電性無機粒子の表面のゼータ電位は、疎水化によりマイナスにシフトする。これにより、粒子形成工程にて、樹脂粒子と非導電性無機粒子との間には静電気力が働くので、第３被覆工程を行った場合であっても、樹脂粒子の表面から非導電性無機粒子が脱落しにくくなる。このため、樹脂粒子の表面に配置する非導電性無機粒子の数を容易に制御できると共に、複合粒子に良好な突起を形成できる。したがって、導電粒子が配合された異方導電性接着剤を用いた接続構造体を高温高湿下に保存した場合であっても、導通信頼性が向上する。加えて、樹脂粒子から脱落する非導電性無機粒子の数を低減できるので、複合粒子に異常に成長した突起が発生しにくくなる。したがって、導電粒子同士が導通しにくくなり、当該導電粒子を用いた接続構造体等の絶縁信頼性も向上する。 According to this production method, the resin particles are coated with the cationic polymer in the first coating step, and the non-conductive inorganic particles are coated with the hydrophobic treatment agent in the second coating step. The zeta potential on the surface of the non-conductive inorganic particles is shifted to minus due to the hydrophobicity. As a result, an electrostatic force acts between the resin particles and the non-conductive inorganic particles in the particle forming step, so even when the third coating step is performed, the non-conductive inorganic particles are formed from the surface of the resin particles. Particles are less likely to fall off. For this reason, while being able to control easily the number of the nonelectroconductive inorganic particles arrange | positioned on the surface of a resin particle, a favorable protrusion can be formed in a composite particle. Therefore, even when the connection structure using the anisotropic conductive adhesive containing conductive particles is stored under high temperature and high humidity, conduction reliability is improved. In addition, since the number of non-conductive inorganic particles falling off from the resin particles can be reduced, abnormally grown protrusions are hardly generated on the composite particles. Therefore, it becomes difficult for conductive particles to conduct | electrically_connect, and insulation reliability, such as a connection structure using the said conductive particle, improves.
　第３被覆工程では、複合粒子を、無電解めっきによりニッケルを含有する第１層によって被覆してもよい。これにより、当該導電粒子が圧縮された場合であっても非導電性無機粒子上に形成されて突起部分となった第１層が押し潰されにくくなる。したがって、導電粒子は、低い導通抵抗を得ることができる。 In the third coating step, the composite particles may be coated with a first layer containing nickel by electroless plating. Thereby, even when the conductive particles are compressed, the first layer that is formed on the non-conductive inorganic particles and becomes a protruding portion is less likely to be crushed. Therefore, the conductive particles can obtain a low conduction resistance.
　第３被覆工程では、貴金属及びコバルトからなる群より選ばれる金属を含有する第２層によって第１層に覆われた複合粒子を被覆してもよい。この場合、導電粒子は、一層低い導通抵抗を得ることができる。 In the third coating step, the composite particles covered with the first layer may be coated with a second layer containing a metal selected from the group consisting of noble metals and cobalt. In this case, the conductive particles can obtain a lower conduction resistance.
　樹脂粒子と非導電性無機粒子とのゼータ電位の差は、ｐＨ１以上ｐＨ１１以下において３０ｍＶ以上であってもよい。この場合、樹脂粒子と非導電性無機粒子とが静電気力により強固に接着する。したがって、第３被覆工程の際等に、樹脂粒子から非導電性無機粒子が脱落することを好適に抑制できる。 The difference in zeta potential between the resin particles and the non-conductive inorganic particles may be 30 mV or more at pH 1 or more and pH 11 or less. In this case, the resin particles and the non-conductive inorganic particles are firmly bonded by electrostatic force. Therefore, it can suppress suitably that a nonelectroconductive inorganic particle falls from the resin particle in the case of a 3rd coating process.
　本発明の一側面によれば、異方導電性接着剤に配合される導電粒子として用いられたときに優れた導通信頼性及び絶縁信頼性を両立することができる導電粒子及びその製造方法が提供される。また、本発明の一側面によれば、当該導電粒子を用いた絶縁被覆導電粒子、異方導電性接着剤及び接続構造体が提供される。 According to one aspect of the present invention, there are provided conductive particles capable of achieving both excellent conduction reliability and insulation reliability when used as conductive particles blended in an anisotropic conductive adhesive, and a method for producing the same. Is done. Moreover, according to one side of this invention, the insulation coating electrically-conductive particle, anisotropic conductive adhesive, and connection structure using the said electrically-conductive particle are provided.
図１は、第１実施形態に係る導電粒子を示す模式断面図である。FIG. 1 is a schematic cross-sectional view showing conductive particles according to the first embodiment. 図２は、第１実施形態に係る導電粒子を示す模式拡大断面図である。FIG. 2 is a schematic enlarged cross-sectional view showing the conductive particles according to the first embodiment. 図３は、第２実施形態に係る導電粒子を示す模式断面図である。FIG. 3 is a schematic cross-sectional view showing conductive particles according to the second embodiment. 図４は、第２実施形態に係る導電粒子を示す模式拡大断面図である。FIG. 4 is a schematic enlarged cross-sectional view showing conductive particles according to the second embodiment. 図５は、第３実施形態に係る絶縁被覆導電粒子を示す模式断面図である。FIG. 5 is a schematic cross-sectional view showing insulating coated conductive particles according to the third embodiment. 図６は、第５実施形態に係る接続構造体を示す模式断面図である。FIG. 6 is a schematic cross-sectional view showing a connection structure according to the fifth embodiment. 図７は、第５実施形態に係る接続構造体の製造方法の一例を説明するための模式断面図である。FIG. 7 is a schematic cross-sectional view for explaining an example of the manufacturing method of the connection structure according to the fifth embodiment. 図８は、実施例１の導電粒子の作製における工程ｄで得られた粒子を観察したＳＥＭ画像である。FIG. 8 is an SEM image obtained by observing the particles obtained in step d in the production of the conductive particles of Example 1. 図９は、実施例１の導電粒子の作製における工程ｄで得られた粒子の表面を観察したＳＥＭ画像である。FIG. 9 is an SEM image obtained by observing the surface of the particles obtained in step d in the production of the conductive particles of Example 1. 図１０は、実施例１の導電粒子の作製における工程ｆで得られた粒子を観察したＳＥＭ画像である。FIG. 10 is an SEM image obtained by observing the particles obtained in step f in the production of the conductive particles of Example 1. 図１１は、実施例１の導電粒子の作製における工程ｆで得られた粒子の表面を観察したＳＥＭ画像である。FIG. 11 is an SEM image obtained by observing the surface of the particles obtained in step f in the production of the conductive particles of Example 1. 図１２は、トリミング加工を説明するための模式図である。FIG. 12 is a schematic diagram for explaining the trimming process. 図１３は、ＴＥＭ測定用の薄膜切片を作製する方法を説明するための模式図である。FIG. 13 is a schematic diagram for explaining a method of producing a thin film slice for TEM measurement. 図１４は、異常析出部を説明するための模式図である。FIG. 14 is a schematic diagram for explaining an abnormal precipitation portion. 図１５は、比較例１において、パラジウム触媒が固着化された樹脂粒子を浸漬した後、超音波分散することで得られた粒子を観察したＳＥＭ画像である。FIG. 15 is an SEM image obtained by observing particles obtained by ultrasonic dispersion after immersing resin particles having a palladium catalyst fixed thereon in Comparative Example 1. 図１６は、比較例１において、第１層のｂ層形成後の導電粒子を観察したＳＥＭ画像である。FIG. 16 is an SEM image obtained by observing the conductive particles after forming the b layer of the first layer in Comparative Example 1.
　以下、図面を参照しつつ本発明の実施形態について詳細に説明する。なお、図面中、同一又は相当部分には同一符号を付し、重複する説明は省略する。また、上下左右等の位置関係は、特に断らない限り、図面に示す位置関係に基づくものとする。さらに、図面の寸法比率は図示の比率に限られるものではない。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.
（第１実施形態）
　以下、第１実施形態に係る導電粒子について説明する。 (First embodiment)
Hereinafter, the conductive particles according to the first embodiment will be described.
＜導電粒子＞
　図１は、第１実施形態に係る導電粒子を示す模式断面図である。図１に示す導電粒子１００ａは、導電粒子のコアを構成する樹脂粒子１０１、及び当該樹脂粒子１０１の表面に配置される非導電性無機粒子１０２を有する複合粒子１０３と、複合粒子１０３を覆う第１層１０４とを備える。樹脂粒子１０１に接着された非導電性無機粒子１０２の形状を反映し、第１層１０４の表面には、突起１０９が形成される。樹脂粒子１０１は、後述するカチオン性ポリマーにより被覆されたものである。非導電性無機粒子１０２は、後述する疎水性処理剤により被覆されたものである。第１層１０４は、金属を少なくとも含む導電層である。第１層１０４は、金属層でもよいし、合金層でもよい。 <Conductive particles>
FIG. 1 is a schematic cross-sectional view showing conductive particles according to the first embodiment. A conductive particle 100 a illustrated in FIG. 1 includes resin particles 101 that form a core of conductive particles, composite particles 103 having non-conductive inorganic particles 102 disposed on the surfaces of the resin particles 101, and first particles that cover the composite particles 103. 1 layer 104. A protrusion 109 is formed on the surface of the first layer 104, reflecting the shape of the non-conductive inorganic particles 102 bonded to the resin particles 101. The resin particles 101 are coated with a cationic polymer described later. The non-conductive inorganic particles 102 are coated with a hydrophobic treating agent described later. The first layer 104 is a conductive layer containing at least a metal. The first layer 104 may be a metal layer or an alloy layer.
　導電粒子１００ａの平均粒径は、例えば、１μｍ以上でもよく、２μｍ以上でもよい。導電粒子１００ａの平均粒径は、例えば、１０μｍ以下でもよく、５μｍ以下でもよい。つまり、導電粒子１００ａの平均粒径は、例えば、１～１０μｍである。導電粒子１００ａの平均粒径が上記範囲内であることにより、例えば、導電粒子１００ａを含む異方導電性接着剤を用いて接続構造体を作製した場合に、当該接続構造体の電極の形状（高さ）のばらつきによって、当該異方導電性接着剤の導電性等が変化しにくくなる。導電粒子１００ａの平均粒径は、走査型電子顕微鏡（以下、「ＳＥＭ」という）を用いた観察により任意の導電粒子３００個の粒径の測定を行うことにより得られる平均値としてもよい。導電粒子１００ａは突起１０９を有するため、導電粒子１００ａの粒径は、ＳＥＭにて撮影した画像において導電粒子１００ａに外接する円の直径とする。精度を上げて導電粒子１００ａの平均粒径を測定するためには、コールターカウンター等の市販の装置を用いることができる。この場合、導電粒子５００００個の粒径の測定を行えば、高い精度で平均粒径を測定することができる。例えば、ＣＯＵＬＥＲ　ＭＵＬＴＩＳＩＺＥＲ　ＩＩ（ベックマン・コールター株式会社製、商品名）により５００００個の導電粒子を測定することにより、導電粒子１００ａの平均粒径を測定してもよい。 The average particle diameter of the conductive particles 100a may be, for example, 1 μm or more, or 2 μm or more. The average particle diameter of the conductive particles 100a may be, for example, 10 μm or less, or 5 μm or less. That is, the average particle diameter of the conductive particles 100a is, for example, 1 to 10 μm. When the average particle diameter of the conductive particles 100a is within the above range, for example, when a connection structure is manufactured using an anisotropic conductive adhesive containing the conductive particles 100a, the shape of the electrodes of the connection structure ( Due to the variation in (height), the conductivity of the anisotropic conductive adhesive is less likely to change. The average particle diameter of the conductive particles 100a may be an average value obtained by measuring the particle diameter of 300 arbitrary conductive particles by observation using a scanning electron microscope (hereinafter referred to as “SEM”). Since the conductive particle 100a has the protrusion 109, the particle diameter of the conductive particle 100a is set to a diameter of a circle circumscribing the conductive particle 100a in an image taken by the SEM. In order to increase the accuracy and measure the average particle diameter of the conductive particles 100a, a commercially available apparatus such as a Coulter counter can be used. In this case, if the particle diameter of 50000 conductive particles is measured, the average particle diameter can be measured with high accuracy. For example, the average particle diameter of the conductive particles 100a may be measured by measuring 50,000 conductive particles using COULER MULTISIZER II (trade name, manufactured by Beckman Coulter, Inc.).
＜樹脂粒子＞
　樹脂粒子１０１は、有機樹脂から構成される。有機樹脂としては、ポリメチルメタクリレート、ポリメチルアクリレート等の（メタ）アクリル樹脂；ポリエチレン、ポリプロピレン等のポリオレフィン樹脂；ポリイソブチレン樹脂；ポリブタジエン樹脂などが挙げられる。樹脂粒子１０１としては、架橋（メタ）アクリル粒子、架橋ポリスチレン粒子等の有機樹脂を架橋して得られた粒子も使用できる。樹脂粒子は、上記有機樹脂の一種から構成されてもよいし、上記有機樹脂の二種以上を組み合わせて構成されてもよい。有機樹脂は、上記樹脂に限定されない。 <Resin particles>
The resin particles 101 are made of an organic resin. Examples of the organic resin include (meth) acrylic resins such as polymethyl methacrylate and polymethyl acrylate; polyolefin resins such as polyethylene and polypropylene; polyisobutylene resins; and polybutadiene resins. As the resin particles 101, particles obtained by crosslinking organic resins such as crosslinked (meth) acrylic particles and crosslinked polystyrene particles can also be used. The resin particles may be composed of one kind of the organic resin or a combination of two or more kinds of the organic resin. The organic resin is not limited to the above resin.
　樹脂粒子１０１は、球状である。樹脂粒子１０１の平均粒径は、例えば、１μｍ以上１０μｍ以下でもよい。樹脂粒子１０１の平均粒径は、例えば、１μｍ以上でもよく、２μｍ以上でもよい。樹脂粒子１０１の平均粒径が１μｍ以上であることにより、導電粒子１００ａの変形量が十分に確保される。樹脂粒子１０１の平均粒径は、例えば、１０μｍ以下でもよく、５μｍ以下でもよい。樹脂粒子１０１の平均粒径が１０μｍ以下であることにより、粒径のばらつきが抑制され、導電粒子１００ａにおける接続抵抗値のばらつきが抑制される。樹脂粒子１０１の平均粒径は、ＳＥＭを用いた観察によって任意の樹脂粒子３００個の粒径の測定を行うことにより得られる平均値とする。 Resin particles 101 are spherical. The average particle diameter of the resin particles 101 may be, for example, 1 μm or more and 10 μm or less. The average particle diameter of the resin particles 101 may be, for example, 1 μm or more, or 2 μm or more. When the average particle diameter of the resin particles 101 is 1 μm or more, the deformation amount of the conductive particles 100a is sufficiently ensured. The average particle diameter of the resin particles 101 may be, for example, 10 μm or less, or 5 μm or less. When the average particle size of the resin particles 101 is 10 μm or less, variations in particle size are suppressed, and variations in connection resistance values in the conductive particles 100a are suppressed. The average particle diameter of the resin particles 101 is an average value obtained by measuring the particle diameter of 300 arbitrary resin particles by observation using an SEM.
＜樹脂粒子の表面処理＞
　上述したように、樹脂粒子１０１には、表面処理としてカチオン性ポリマーが被覆される。このカチオン性ポリマーとしては、一般に、ポリアミン等のように正荷電を帯びることのできる官能基を有する高分子化合物が挙げられる。カチオン性ポリマーは、例えば、ポリアミン、ポリイミン、ポリアミド、ポリジアリルジメチルアンモニウムクロリド、ポリビニルアミン、ポリビニルピリジン、ポリビニルイミダゾール及びポリビニルピロリドンからなる群より選ばれてもよい。電荷密度が高く、負の電荷を持った表面及び材料との結合力が強い観点から、ポリイミンが好ましく、ポリエチレンイミンがより好ましい。カチオン性ポリマーは、水、又は、水と有機溶媒との混合溶液に可溶であってもよい。カチオン性ポリマーの分子量は、用いるカチオン性ポリマーの種類により変化するが、例えば、５００～２０００００程度である。 <Surface treatment of resin particles>
As described above, the resin particles 101 are coated with a cationic polymer as a surface treatment. Examples of the cationic polymer generally include a polymer compound having a functional group capable of being positively charged, such as polyamine. The cationic polymer may be selected from the group consisting of, for example, polyamine, polyimine, polyamide, polydiallyldimethylammonium chloride, polyvinylamine, polyvinylpyridine, polyvinylimidazole, and polyvinylpyrrolidone. Polyimine is preferable and polyethyleneimine is more preferable from the viewpoint of high charge density and strong binding force to negatively charged surfaces and materials. The cationic polymer may be soluble in water or a mixed solution of water and an organic solvent. The molecular weight of the cationic polymer varies depending on the type of the cationic polymer used, but is, for example, about 500 to 200,000.
　カチオン性ポリマーの種類及び分子量を調整することにより、非導電性無機粒子１０２による樹脂粒子１０１の被覆率をコントロールすることができる。具体的には、ポリエチレンイミン等の電荷密度が高いカチオン性ポリマーによって樹脂粒子１０１が被覆された場合、非導電性無機粒子１０２の被覆率（非導電性無機粒子１０２が樹脂粒子１０１を被覆する割合）が高くなる傾向がある。一方、電荷密度の低いカチオン性ポリマーによって樹脂粒子１０１が被覆された場合、非導電性無機粒子１０２の被覆率が低くなる傾向がある。カチオン性ポリマーの分子量が大きい場合、非導電性無機粒子１０２の被覆率が高くなる傾向があり、カチオン性ポリマーの分子量が小さい場合、非導電性無機粒子１０２の被覆率が低くなる傾向がある。 By adjusting the kind and molecular weight of the cationic polymer, the coverage of the resin particles 101 with the non-conductive inorganic particles 102 can be controlled. Specifically, when the resin particles 101 are coated with a cationic polymer having a high charge density such as polyethyleneimine, the coverage of the nonconductive inorganic particles 102 (the ratio of the nonconductive inorganic particles 102 covering the resin particles 101) ) Tends to be high. On the other hand, when the resin particles 101 are coated with a cationic polymer having a low charge density, the coverage of the non-conductive inorganic particles 102 tends to be low. When the molecular weight of the cationic polymer is large, the coverage of the nonconductive inorganic particles 102 tends to be high, and when the molecular weight of the cationic polymer is small, the coverage of the nonconductive inorganic particles 102 tends to be low.
　カチオン性ポリマーは、アルカリ金属（Ｌｉ、Ｎａ、Ｋ、Ｒｂ、Ｃｓ）イオン、アルカリ土類金属（Ｃａ、Ｓｒ、Ｂａ、Ｒａ）イオン、及びハロゲン化物イオン（フッ素イオン、クロライドイオン、臭素イオン、ヨウ素イオン）を実質的に含まなくてもよい。この場合、カチオン性ポリマーが被覆された樹脂粒子１０１のエレクトロマイグレーション及び腐食が抑制される。 Cationic polymers include alkali metal (Li, Na, K, Rb, Cs) ion, alkaline earth metal (Ca, Sr, Ba, Ra) ion, and halide ion (fluorine ion, chloride ion, bromine ion, iodine). Ions) may be substantially absent. In this case, electromigration and corrosion of the resin particles 101 coated with the cationic polymer are suppressed.
　カチオン性ポリマーに被覆される前の樹脂粒子１０１は、水酸基、カルボキシル基、アルコキシ基、グリシジル基及びアルコキシカルボニル基から選ばれる官能基を表面に有する。これにより、樹脂粒子１０１の表面にカチオン性ポリマーが吸着しやすくなる。 The resin particles 101 before being coated with the cationic polymer have a functional group selected from a hydroxyl group, a carboxyl group, an alkoxy group, a glycidyl group and an alkoxycarbonyl group on the surface. Thereby, the cationic polymer is easily adsorbed on the surface of the resin particle 101.
　カチオン性ポリマーが被覆された樹脂粒子１０１のゼータ電位は、水、有機溶媒、又は、水と有機溶媒とを含んだ混合溶液のいずれにおいても、プラス（正の値）になることが好ましい。一般に、ｐＨが低い程、微粒子のゼータ電位はよりプラスになる。このため、第１層１０４を形成するためのめっき液、及び、めっきの前処理工程で使用される前処理液のｐＨを６以下にコントロールすることが好ましい。 The zeta potential of the resin particles 101 coated with the cationic polymer is preferably positive (positive value) in any of water, an organic solvent, or a mixed solution containing water and an organic solvent. In general, the lower the pH, the more positive the fine particle zeta potential. For this reason, it is preferable to control the pH of the plating solution for forming the first layer 104 and the pretreatment solution used in the pretreatment step of plating to 6 or less.
　樹脂粒子１０１のゼータ電位は、例えば、ゼータ電位プローブ（Ｄｉｓｐｅｒｓｉｏｎ　Ｔｅｃｈｎｏｌｏｇｉｅｓ社製、商品名「ＤＴ３００」）を用いて、コロイド振動電位を測定することにより、もしくは、Ｚｅｔａｓｉｚｅｒ　ＺＳ（Ｍａｌｖｅｒｎ　Ｉｎｓｔｒｕｍｅｎｔｓ社製、商品名）を用いたレーザドップラー速度計測により電気泳動移動度を測定することによって、測定することができる。 The zeta potential of the resin particle 101 is measured by measuring the colloid vibration potential using, for example, a zeta potential probe (manufactured by Dispersion Technologies, trade name “DT300”), or by Zetasizer ZS (product of Malvern Instruments, trade name). ) To measure the electrophoretic mobility by laser Doppler velocity measurement.
＜非導電性無機粒子＞
　非導電性無機粒子１０２は、後述するように、静電気力により樹脂粒子１０１に強固に接着されている。非導電性無機粒子１０２の形状は、特に制限されないが、楕円体、球体、半球体、略楕円体、略球体、略半球体等である。これらの中でも楕円体又は球体であることが好ましい。 <Non-conductive inorganic particles>
As described later, the non-conductive inorganic particles 102 are firmly bonded to the resin particles 101 by electrostatic force. The shape of the non-conductive inorganic particles 102 is not particularly limited, but may be an ellipsoid, a sphere, a hemisphere, a substantially ellipsoid, a substantially sphere, a substantially hemisphere, or the like. Among these, an ellipsoid or a sphere is preferable.
　第１層１０４の形成前であって第１層１０４形成における前処理（詳細は後述する）の終了後の段階で、非導電性無機粒子１０２による樹脂粒子１０１の被覆率が２０～８０％となればよい。導電粒子１００ａの絶縁性及び導電性の効果をより確実に得る観点から、上記被覆率は、２５％以上であってもよく、３０％以上であってもよく、７０％以下であってもよく、６０％以下であってもよい。本実施形態では、「被覆率」は、樹脂粒子１０１の正投影面において、当該樹脂粒子１０１の直径の１／２の直径を有する同心円内における非導電性無機粒子１０２の表面積の割合を意味する。具体的には、非導電性無機粒子１０２が形成された樹脂粒子１０１をＳＥＭにより３万倍で観察して得られる画像を解析し、樹脂粒子１０１の表面において非導電性無機粒子１０２が占める割合を算出する。 Before the formation of the first layer 104 and after the completion of the pretreatment (details will be described later) in the formation of the first layer 104, the coverage of the resin particles 101 with the non-conductive inorganic particles 102 is 20 to 80%. It only has to be. From the viewpoint of more reliably obtaining the insulating and conductive effects of the conductive particles 100a, the coverage may be 25% or more, 30% or more, or 70% or less. 60% or less. In the present embodiment, the “coverage” means the ratio of the surface area of the non-conductive inorganic particles 102 in a concentric circle having a diameter that is ½ of the diameter of the resin particles 101 on the orthographic projection surface of the resin particles 101. . Specifically, an image obtained by observing the resin particles 101 on which the non-conductive inorganic particles 102 are formed at 30,000 times by SEM is analyzed, and the ratio of the non-conductive inorganic particles 102 to the surface of the resin particles 101 Is calculated.
　第１層１０４の外表面に充分な数の突起１０９を形成し、導電粒子１００ａが電極などに接続したときの導通抵抗を更に下げる観点から、非導電性無機粒子１０２は、導電粒子１００ａの径方向に垂直な方向（表面）に点在的に配置されてもよい。非導電性無機粒子１０２同士は互いに接触することなく、導電粒子１００ａの径方向に垂直な方向（表面）に点在的に配置されてもよい。互いに接触する非導電性無機粒子１０２の数は、例えば、一つの導電粒子１００ａ中に１５個以下でもよく、７個以下でもよく、０個でもよい。０個とは、一つの導電粒子１００ａの表面に配置される非導電性無機粒子１０２同士が接触せず、すべての非導電性無機粒子１０２が点在的に配置されていることを意味する。 From the viewpoint of forming a sufficient number of protrusions 109 on the outer surface of the first layer 104 and further reducing the conduction resistance when the conductive particles 100a are connected to electrodes or the like, the non-conductive inorganic particles 102 have a diameter of the conductive particles 100a. You may disperse | distribute to the direction (surface) perpendicular | vertical to a direction. The non-conductive inorganic particles 102 may be arranged in a dotted manner in the direction (surface) perpendicular to the radial direction of the conductive particles 100a without contacting each other. The number of non-conductive inorganic particles 102 in contact with each other may be, for example, 15 or less, 7 or less, or 0 in one conductive particle 100a. Zero means that the nonconductive inorganic particles 102 arranged on the surface of one conductive particle 100a are not in contact with each other, and all the nonconductive inorganic particles 102 are arranged in a scattered manner.
　非導電性無機粒子１０２を形成する材料は、第１層１０４を形成する材料よりも硬くてもよい。これにより、導電粒子が電極等に突き刺さりやすくなり、導電性が向上する。つまり、導電粒子全体を硬くするのではなく、導電粒子の一部を硬くするという考え方である。例えば、非導電性無機粒子１０２を形成する材料のモース硬度は、第１層１０４を形成する金属のモース硬度よりも大きい。具体的には、非導電性無機粒子１０２を形成する材料のモース硬度は、５以上である。加えて、非導電性無機粒子１０２を形成する材料のモース硬度と第１層１０４を形成する金属のモース硬度との差は、１．０以上であってもよい。第１層１０４が複数の金属を含有する場合、非導電性無機粒子１０２のモース硬度が全ての金属のモース硬度よりも高くてもよい。具体例としては、非導電性無機粒子１０２を形成する材料は、シリカ（二酸化ケイ素（ＳｉＯ２）、モース硬度６～７）、ジルコニア（モース硬度８～９）、アルミナ（モース硬度９）及びダイヤモンド（モース硬度１０）からなる群から選ばれてもよい。非導電性無機粒子１０２の表面には水酸基（－ＯＨ）が形成されており、上述したように疎水化処理剤が被覆されている。上記モース硬度の値は、「化学大辞典」（共立出版株式会社発行）を参照した。 The material forming the non-conductive inorganic particles 102 may be harder than the material forming the first layer 104. Thereby, it becomes easy for the conductive particles to pierce the electrode or the like, and the conductivity is improved. That is, the idea is not to harden the entire conductive particles but to harden some of the conductive particles. For example, the Mohs hardness of the material forming the non-conductive inorganic particles 102 is larger than the Mohs hardness of the metal forming the first layer 104. Specifically, the Mohs hardness of the material forming the non-conductive inorganic particles 102 is 5 or more. In addition, the difference between the Mohs hardness of the material forming the non-conductive inorganic particles 102 and the Mohs hardness of the metal forming the first layer 104 may be 1.0 or more. When the first layer 104 contains a plurality of metals, the Mohs hardness of the non-conductive inorganic particles 102 may be higher than the Mohs hardness of all metals. As specific examples, materials for forming the non-conductive inorganic particles 102 are silica (silicon dioxide (SiO 2 ), Mohs hardness 6-7), zirconia (Mohs hardness 8-9), alumina (Mohs hardness 9), and diamond. You may select from the group which consists of (Mohs hardness 10). Hydroxyl groups (—OH) are formed on the surfaces of the non-conductive inorganic particles 102 and are coated with the hydrophobizing agent as described above. The value of the Mohs hardness was referred to “Chemical Dictionary” (published by Kyoritsu Shuppan Co., Ltd.).
　非導電性無機粒子１０２として、シリカ粒子を用いてもよい。シリカ粒子の粒径は、制御されていることが好ましい。シリカ粒子の種類としては、特に制限されず、コロイダルシリカ、フュームドシリカ、ゾルゲル法シリカ等が挙げられる。シリカ粒子は、単独でもよいし、２種以上混合して用いてもよい。シリカ粒子として、市販品を用いてもよく、合成品を用いてもよい。 Silica particles may be used as the nonconductive inorganic particles 102. The particle size of the silica particles is preferably controlled. The type of silica particles is not particularly limited, and examples thereof include colloidal silica, fumed silica, and sol-gel silica. Silica particles may be used alone or in combination of two or more. As silica particles, commercially available products or synthetic products may be used.
　コロイダルシリカの製造方法としては、公知の方法が挙げられる。具体的には、「ゾル－ゲル法の科学」（作花済夫著、アグネ承風社発行）の第１５４～１５６頁に記載のアルコキシシランの加水分解による方法；特開平１１－６０２３２号公報に記載の、ケイ酸メチルまたはケイ酸メチルとメタノールとの混合物を、水、メタノール、及び、アンモニアまたはアンモニアとアンモニウム塩からなる混合溶媒中に滴下して、ケイ酸メチルと水とを反応させる方法；特開２００１－４８５２０号公報に記載の、アルキルシリケー卜を酸触媒で加水分解した後、アルカリ触媒を加えて加熱してケイ酸の重合を進行させて粒子成長させる方法；特開２００７－１５３７３２号公報に記載の、アルコキシシランの加水分解の際に特定の種類の加水分解触媒を特定の量で使用する方法等が挙げられる。もしくは、ケイ酸ソーダをイオン交換することにより製造する方法も挙げられる。水分散コロイダルシリカの市販品としては、スノーテックス、スノーテックスＵＰ（いずれも日産化学工業株式会社製、商品名）、クオートロンＰＬシリーズ（扶桑化学工業株式会社製、商品名）等が挙げられる。 As a method for producing colloidal silica, known methods may be mentioned. Specifically, a method by hydrolysis of alkoxysilane described in pages 154 to 156 of “Science of Sol-Gel Process” (Sakuo Sakuo, published by Agne Sefu Co., Ltd.); JP-A-11-60232 A method of reacting methyl silicate and water by dropping methyl silicate or a mixture of methyl silicate and methanol into water, methanol and a mixed solvent composed of ammonia or ammonia and an ammonium salt, as described in 1. A method described in JP-A-2001-48520, in which alkyl silicate cake is hydrolyzed with an acid catalyst, and then an alkali catalyst is added and heated to advance polymerization of silicic acid to grow particles; JP-A-2007- And a method of using a specific type of hydrolysis catalyst in a specific amount at the time of hydrolysis of alkoxysilane, as described in Japanese Patent No. 153732. Or the method of manufacturing by ion-exchange of sodium silicate is also mentioned. Examples of commercially available water-dispersed colloidal silica include Snowtex, Snowtex UP (both manufactured by Nissan Chemical Industries, Ltd., trade name), Quatron PL series (manufactured by Fuso Chemical Industries, Ltd., trade name), and the like.
　フュームドシリカの製造方法としては、四塩化ケイ素を気化し、酸水素炎中で燃焼させる気相反応を用いる公知の方法が挙げられる。さらに、フュームドシリカは、公知の方法で水分散液とすることができる。水分散液とする方法としては、特開２００４－４３２９８号公報、特開２００３－１７６１２３号公報、特開２００２－３０９２３９号公報等に記載の方法が挙げられる。フュームドシリカの絶縁信頼性の観点から、水分散液中のアルカリ金属イオン及びアルカリ土類金属イオンの濃度が１００ｐｐｍ以下であることが好ましい。フュームドシリカのモース硬度は、５以上でもよく、６以上でもよい。 As a method for producing fumed silica, a known method using a gas phase reaction in which silicon tetrachloride is vaporized and burned in an oxyhydrogen flame can be mentioned. Furthermore, fumed silica can be made into an aqueous dispersion by a known method. Examples of the method for preparing an aqueous dispersion include the methods described in JP-A No. 2004-43298, JP-A No. 2003-176123, JP-A No. 2002-309239, and the like. From the viewpoint of the insulation reliability of fumed silica, the concentration of alkali metal ions and alkaline earth metal ions in the aqueous dispersion is preferably 100 ppm or less. The Mohs hardness of fumed silica may be 5 or more, or 6 or more.
＜疎水化処理剤＞
　非導電性無機粒子１０２を被覆する疎水化処理剤としては、以下に記載の、（１）シラザン系疎水化処理剤、（２）シロキサン系疎水化処理剤、（３）シラン系疎水化処理剤、（４）チタネート系疎水化処理剤等が挙げられる。反応性の観点から、（１）シラザン系疎水化処理剤が好ましい。疎水化処理剤は、上記（１）～（４）からなる群から選択される少なくとも一種を含んでもよい。 <Hydrophobicizing agent>
Examples of the hydrophobizing agent that coats the non-conductive inorganic particles 102 include the following (1) silazane hydrophobizing agent, (2) siloxane hydrophobizing agent, and (3) silane hydrophobizing agent. (4) Titanate-based hydrophobizing agents and the like. From the viewpoint of reactivity, (1) a silazane hydrophobizing agent is preferred. The hydrophobizing agent may contain at least one selected from the group consisting of the above (1) to (4).
（１）シラザン系疎水化処理剤
　シラザン系疎水化処理剤としては、例えば、有機シラザン系疎水化処理剤が挙げられる。有機シラザン系疎水化処理剤としては、ヘキサメチルジシラザン、トリメチルジシラザン、テトラメチルジシラザン、ヘキサメチルシクロトリシラザン、ヘプタメチルジシラザン、ジフェニルテトラメチルジシラザン、ジビニルテトラメチルジシラザン等が挙げられる。有機シラザン系疎水化処理剤は、上記以外のものでもよい。 (1) Silazane-based hydrophobizing agent The silazane-based hydrophobizing agent includes, for example, an organic silazane-based hydrophobizing agent. Examples of the organic silazane hydrophobizing agent include hexamethyldisilazane, trimethyldisilazane, tetramethyldisilazane, hexamethylcyclotrisilazane, heptamethyldisilazane, diphenyltetramethyldisilazane, divinyltetramethyldisilazane, and the like. . The organic silazane-based hydrophobizing agent may be other than the above.
（２）シロキサン系疎水化処理剤
　シロキサン系疎水化処理剤としては、ポリジメチルシロキサン、メチルハイドロジェンジシロキサン、ジメチルジシロキサン、ヘキサメチルジシロキサン、１，３－ジビニルテトラメチルジシロキサン、１，３－ジフェニルテトラメチルジシロキサン、メチルハイドロジェンポリシロキサン、ジメチルポリシロキサン、アミノ変性シロキサン等が挙げられる。シロキサン系疎水化処理剤は、上記以外のものでもよい。 (2) Siloxane-based hydrophobizing agent As siloxane-based hydrophobizing agents, polydimethylsiloxane, methylhydrogendisiloxane, dimethyldisiloxane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3 -Diphenyltetramethyldisiloxane, methylhydrogenpolysiloxane, dimethylpolysiloxane, amino-modified siloxane and the like. The siloxane-based hydrophobizing agent may be other than the above.
（３）シラン系疎水化処理剤
　シラン系疎水化処理剤としては、Ｎ，Ｎ－ジメチルアミノトリメチルシラン、トリメチルメトキシシラン、トリメチルエトキシシラン、トリメチルプロポキシシラン、フェニルジメチルメトキシシラン、クロロプロピルジメチルメトキシシラン、ジメチルジメトキシシラン、メチルトリメトキシシラン、テトラメトキシシラン、テトラエトキシシラン、テトラプロポキシシラン、テトラブトキシシラン、エチルトリメトキシシラン、ジメチルジエトキシシラン、プロピルトリエトキシシラン、ｎ－ブチルトリメトキシシラン、ｎ－ヘキシルトリメトキシシラン、ｎ－オクチルトリエトキシシラン、ｎ－オクチルメチルジエトキシシラン、ｎ－オクタデシルトリメトキシシラン、フェニルトリメトキシシラン、フェニルメチルジメトキシシラン、フェネチルトリメトキシシラン、ドデシルトリメトキシシラン、ｎ－オクタデシルトリエトキシシラン、フェニルトリメトキシシラン、ジフェニルジメトキシシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン、ビニルトリス（βメトキシエトキシ）シラン、γ－メタアクリルオキシプロピルトリメトキシシラン、γ－アクリルオキシプロピルトリメトキシシラン、γ－（メタアクリルオキシプロピル）メチルジメトキシシラン、γ－メタアクリルオキシプロピルメチルジエトキシシラン、γ－メタアクリルオキシプロピルトリエトキシシラン、β－（３，４－エポキシシクロヘキシル）エチルトリメトキシシラン、γ－グリシドキシプロピルトリメトキシシラン、γ－グリシドキシプロピルメチルジエトキシシラン、γ－グリシドキシプロピルトリエトキシシラン、Ｎ－β（アミノエチル）γ－（アミノプロピル）メチルジメトキシシラン、Ｎ－β（アミノエチル）γ－（アミノプロピル）トリメトキシシラン、Ｎ－β（アミノエチル）γ－（アミノプロピル）トリエトキシシラン、γ－アミノプロピルトリメトキシシラン、γ－アミノプロピルトリエトキシシラン、Ｎ－フェニル－γ－アミノプロピルトリメトキシシラン、γ－メルカプトプロピルトリメトキシシラン、３－イソシアネートプロピルトリエトキシシラン、トリフルオロプロピルトリメトキシシラン、ヘプタデカトリフルオロプロピルトリメトキシシラン、ｎ－デシルトリメトキシシラン、ジメトキシジエトキシシラン、ビス（トリエトキシシリル）エタン、ヘキサエトキシジシロキサン等が挙げられる。 (3) Silane-based hydrophobizing agent As silane-based hydrophobizing agents, N, N-dimethylaminotrimethylsilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylpropoxysilane, phenyldimethylmethoxysilane, chloropropyldimethylmethoxysilane, Dimethyldimethoxysilane, methyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, ethyltrimethoxysilane, dimethyldiethoxysilane, propyltriethoxysilane, n-butyltrimethoxysilane, n-hexyl Trimethoxysilane, n-octyltriethoxysilane, n-octylmethyldiethoxysilane, n-octadecyltrimethoxysilane, phenyltrimethoxysilane, Nylmethyldimethoxysilane, phenethyltrimethoxysilane, dodecyltrimethoxysilane, n-octadecyltriethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (βmethoxyethoxy) silane, γ -Methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ- (methacryloxypropyl) methyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane , Β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldie Xysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ- (aminopropyl) methyldimethoxysilane, N-β (aminoethyl) γ- (aminopropyl) trimethoxysilane, N-β ( Aminoethyl) γ- (aminopropyl) triethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3 -Isocyanatopropyltriethoxysilane, trifluoropropyltrimethoxysilane, heptadecatrifluoropropyltrimethoxysilane, n-decyltrimethoxysilane, dimethoxydiethoxysilane, bis (triethoxysilyl) ethane, hexaethoxydisiloxy Emissions, and the like.
（４）チタネート系疎水化処理剤
　チタネート系疎水化処理剤としては、ＫＲＴＴＳ、ＫＲ４６Ｂ、ＫＲ５５、ＫＲ４１Ｂ、ＫＲ３８Ｓ、ＫＲ１３８Ｓ、ＫＲ２３８Ｓ、３３８Ｘ、ＫＲ４４、ＫＲ９ＳＡ（いずれも、味の素ファインテクノ株式会社製、商品名）等が挙げられる。 (4) Titanate-based hydrophobizing agents Titanate-based hydrophobizing agents include KRTTS, KR46B, KR55, KR41B, KR38S, KR138S, KR238S, 338X, KR44, and KR9SA (all manufactured by Ajinomoto Fine Techno Co., Ltd., trade names) ) And the like.
　上記疎水化処理剤の中で、ヘキサメチレンジシラザン、ポリジメチルシロキサン、及び、Ｎ，Ｎ－ジメチルアミノトリメチルシランが好ましい。したがって、疎水化処理剤は、ヘキサメチレンジシラザン、ポリジメチルシロキサン、及び、Ｎ，Ｎ－ジメチルアミノトリメチルシランからなる群から選択される少なくとも一つを含んでもよい。非導電性無機粒子１０２の表面が疎水化されるほど、非導電性無機粒子１０２のゼータ電位がマイナス側に大きくなる。このため、非導電性無機粒子１０２とカチオン性ポリマーが被覆された樹脂粒子１０１との電位差が大きくなる。したがって、樹脂粒子１０１と非導電性無機粒子１０２とが、静電気力により強固に接着される。例えば、非導電性無機粒子１０２のゼータ電位と、樹脂粒子１０１とのゼータ電位との差が、ｐＨ１以上ｐＨ１１以下において３０ｍＶ以上でもよく、５０ｍＶ以上でもよい。 Among the above hydrophobizing agents, hexamethylene disilazane, polydimethylsiloxane, and N, N-dimethylaminotrimethylsilane are preferable. Therefore, the hydrophobizing agent may contain at least one selected from the group consisting of hexamethylene disilazane, polydimethylsiloxane, and N, N-dimethylaminotrimethylsilane. As the surface of the non-conductive inorganic particles 102 becomes hydrophobic, the zeta potential of the non-conductive inorganic particles 102 increases toward the negative side. For this reason, the potential difference between the non-conductive inorganic particles 102 and the resin particles 101 coated with the cationic polymer is increased. Therefore, the resin particles 101 and the non-conductive inorganic particles 102 are firmly bonded by electrostatic force. For example, the difference between the zeta potential of the non-conductive inorganic particles 102 and the zeta potential of the resin particles 101 may be 30 mV or more or 50 mV or more at pH 1 or more and pH 11 or less.
　疎水化処理された非導電性無機粒子１０２のゼータ電位は、水、有機溶媒、水と有機溶媒とを含んだ混合溶液、のいずれにおいても、マイナス（負の値）になることが好ましい。一般に、ｐＨが高い程、ゼータ電位はよりマイナスになる。したがって、樹脂粒子１０１と非導電性無機粒子１０２とのゼータ電位の差が大きくなるｐＨを選定することが好ましい。 The zeta potential of the hydrophobic non-conductive inorganic particles 102 is preferably negative (negative value) in any of water, an organic solvent, and a mixed solution containing water and an organic solvent. In general, the higher the pH, the more negative the zeta potential. Therefore, it is preferable to select a pH at which the difference in zeta potential between the resin particles 101 and the non-conductive inorganic particles 102 is large.
　非導電性無機粒子１０２のゼータ電位は、例えば、ゼータ電位プローブ（Ｄｉｓｐｅｒｓｉｏｎ　Ｔｅｃｈｎｏｌｏｇｉｅｓ社製、商品名「ＤＴ３００」）を用いて、コロイド振動電位を測定することにより、もしくは、Ｚｅｔａｓｉｚｅｒ　ＺＳ（Ｍａｌｖｅｒｎ　Ｉｎｓｔｒｕｍｅｎｔｓ社製、商品名）を用いたレーザドップラー速度計測により電気泳動移動度を測定することにより、測定することができる。 The zeta potential of the non-conductive inorganic particles 102 can be determined by measuring the colloid vibration potential using a zeta potential probe (manufactured by Dispersion Technologies, trade name “DT300”), or by Zetasizer ZS (Malvern Instruments, Inc.). It can be measured by measuring the electrophoretic mobility by laser Doppler velocity measurement using a trade name).
　以下では、カチオン性ポリマーが被覆された樹脂粒子１０１と、疎水化処理剤が被覆された非導電性無機粒子１０２とが、化学結合力ではなく、静電気力により強固に接着される理由の考察を記載する。例えば、下記化学式１のように水酸基が付与されたシリカ粒子に対してヘキサメチレンジシラザンにより疎水化処理を行う。この場合、下記化学式２のように、シリカ粒子はメチル基により被覆される。シリカ粒子がメチル基により被覆されることで、樹脂粒子１０１表面に被覆されたカチオン性ポリマーとシリカ粒子との間に化学結合する箇所が無いにもかかわらず、非導電性無機粒子１０２は樹脂粒子１０１に強固に接着される。各非導電性無機粒子の粒径を同一とした場合、ヘキサメチレンジシラザンにより疎水化処理剤が被覆された非導電性無機粒子１０２のゼータ電位は、上述した非導電性無機粒子の中で最もマイナスな電位を示した。このとき、非導電性無機粒子１０２とカチオン性ポリマーとの電位差が最大になることが分かった。このような理由から、樹脂粒子１０１と非導電性無機粒子１０２との接着を向上させるためには、ゼータ電位の差、すなわち樹脂粒子１０１と非導電性無機粒子１０２との電位差によって生じる静電気力が接着性を左右する重要な因子であると考えられる。 Hereinafter, the reason why the resin particles 101 coated with the cationic polymer and the non-conductive inorganic particles 102 coated with the hydrophobizing agent are firmly bonded not by chemical bonding force but by electrostatic force will be discussed. Describe. For example, hydrophobization treatment is performed with hexamethylene disilazane on silica particles to which a hydroxyl group is added as shown in the following chemical formula 1. In this case, as shown in the following chemical formula 2, the silica particles are coated with methyl groups. Since the silica particles are coated with methyl groups, the non-conductive inorganic particles 102 are resin particles even though there is no chemical bond between the cationic polymer coated on the surface of the resin particles 101 and the silica particles. It is firmly bonded to 101. When the particle diameter of each non-conductive inorganic particle is the same, the zeta potential of the non-conductive inorganic particle 102 coated with the hydrophobizing agent with hexamethylene disilazane is the highest among the non-conductive inorganic particles described above. It showed a negative potential. At this time, it was found that the potential difference between the non-conductive inorganic particles 102 and the cationic polymer was maximized. For this reason, in order to improve the adhesion between the resin particles 101 and the non-conductive inorganic particles 102, the electrostatic force generated by the difference in zeta potential, that is, the potential difference between the resin particles 101 and the non-conductive inorganic particles 102 is increased. This is considered to be an important factor that affects the adhesion.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000002
Figure JPOXMLDOC01-appb-C000002
　疎水化処理剤としては、非導電性無機粒子１０２の疎水性を阻害せず、非導電性無機粒子１０２のゼータ電位をマイナス側に保持し、かつ、樹脂粒子１０１と非導電性無機粒子１０２との静電気的な接着を阻害しない範囲内で、アミノ基、カルボン酸基、水酸基、スルフォン酸基、グリシジル基、及びニトリル基からなる群から選択される少なくとも一種を有していてもよい。上記疎水化処理剤以外に、アミノ基、カルボン酸基、水酸基、スルフォン酸基、グリシジル基、及びニトリル基からなる群から選択される少なくとも一種を有すると共に疎水性の効果を阻害しない処理剤を別途追加してもよい。疎水化処理剤にアミノ基、カルボン酸基、水酸基、スルフォン酸基、グリシジル基、及びニトリル基からなる群から選択される少なくとも一種を有していること、また、アミノ基、カルボン酸基、水酸基、スルフォン酸基、グリシジル基、及びニトリル基からなる群から選択される少なくとも一種を有すると共に疎水性の効果を阻害しない処理剤を別途追加することの利点を以下にて説明する。第１層１０４を形成するための前処理工程として、複合粒子１０３に対して後述するパラジウム触媒化処理を行うとき、上記処理剤を用いる。すると、非導電性無機粒子１０２表面へのパラジウム触媒の吸着を促進できる。これにより、複合粒子１０３の表面のパラジウム吸着量が増加するので、パラジウム触媒を介した複合粒子１０３の表面に第１層１０４を均一に形成できる。 As the hydrophobizing agent, the hydrophobicity of the non-conductive inorganic particles 102 is not inhibited, the zeta potential of the non-conductive inorganic particles 102 is maintained on the negative side, and the resin particles 101 and the non-conductive inorganic particles 102 May be at least one selected from the group consisting of an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, and a nitrile group. In addition to the hydrophobizing agent, a treating agent that has at least one selected from the group consisting of an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, and a nitrile group and that does not inhibit the hydrophobic effect is separately provided. May be added. The hydrophobizing agent has at least one selected from the group consisting of an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, and a nitrile group, and an amino group, a carboxylic acid group, and a hydroxyl group The advantages of separately adding a treating agent that has at least one selected from the group consisting of a sulfonic acid group, a glycidyl group, and a nitrile group and that does not inhibit the hydrophobic effect will be described below. As a pretreatment step for forming the first layer 104, the above treatment agent is used when performing the palladium catalyst treatment described later on the composite particles 103. Then, the adsorption of the palladium catalyst on the surface of the non-conductive inorganic particles 102 can be promoted. Thereby, since the amount of palladium adsorption on the surface of the composite particle 103 increases, the first layer 104 can be uniformly formed on the surface of the composite particle 103 via the palladium catalyst.
　非導電性無機粒子１０２の平均粒径は、例えば、樹脂粒子１０１の平均粒径の１／３００～１／１０程度である。非導電性無機粒子１０２の平均粒径が樹脂粒子１０１の平均粒径の１／３００以上である場合、複合粒子１０３を第１層１０４で覆った際に、充分な高さの突起１０９が得られやすい。一方で、非導電性無機粒子１０２の平均粒径が樹脂粒子１０１の平均粒径の１／１０以下である場合、非導電性無機粒子１０２が樹脂粒子１０１から脱落しにくくなる傾向にある。非導電性無機粒子１０２が樹脂粒子１０１により安定して吸着し、充分な高さの突起１０９を得るためには、非導電性無機粒子１０２の平均粒径は、樹脂粒子１０１の平均粒径の１／２００～１／１０であることが好ましく、１／１２０～１／２５程度であることがより好ましい。このように、非導電性無機粒子１０２の平均粒径が上記範囲内であることにより、導電粒子１００ａは緻密な突起１０９を多数有することができると共に、非導電性無機粒子１０２が樹脂粒子１０１から脱落しにくくなる。 The average particle diameter of the nonconductive inorganic particles 102 is, for example, about 1/300 to 1/10 of the average particle diameter of the resin particles 101. When the average particle diameter of the non-conductive inorganic particles 102 is 1/300 or more of the average particle diameter of the resin particles 101, a sufficiently high protrusion 109 is obtained when the composite particles 103 are covered with the first layer 104. It is easy to be done. On the other hand, when the average particle diameter of the non-conductive inorganic particles 102 is 1/10 or less of the average particle diameter of the resin particles 101, the non-conductive inorganic particles 102 tend not to drop off from the resin particles 101. In order to stably adsorb the non-conductive inorganic particles 102 by the resin particles 101 and obtain the protrusions 109 having a sufficiently high height, the average particle diameter of the non-conductive inorganic particles 102 is equal to the average particle diameter of the resin particles 101. It is preferably 1/200 to 1/10, more preferably about 1/120 to 1/25. As described above, when the average particle diameter of the non-conductive inorganic particles 102 is within the above range, the conductive particles 100 a can have a large number of dense protrusions 109, and the non-conductive inorganic particles 102 are separated from the resin particles 101. It becomes difficult to drop off.
　本実施形態では、非導電性無機粒子１０２の好ましい平均粒径の範囲は、例えば、樹脂粒子１０１の平均粒径が３μｍの場合には、２５～１２０ｎｍである。また、例えば、樹脂粒子１０１の平均粒径が、４μｍの場合には３３～１６０ｎｍであることが好ましく、５μｍの場合には４２～２００ｎｍであること好ましく、１０μｍの場合には８３～４００ｎｍであることが好ましい。非導電性無機粒子１０２について、例えば、樹脂粒子１０１の平均粒径が３μｍの場合を例として以下に示す。 In this embodiment, the preferable average particle diameter range of the non-conductive inorganic particles 102 is, for example, 25 to 120 nm when the average particle diameter of the resin particles 101 is 3 μm. Further, for example, the average particle diameter of the resin particles 101 is preferably 33 to 160 nm when it is 4 μm, preferably 42 to 200 nm when it is 5 μm, and 83 to 400 nm when it is 10 μm. It is preferable. For the non-conductive inorganic particles 102, for example, the case where the average particle diameter of the resin particles 101 is 3 μm is shown below as an example.
　非導電性無機粒子１０２の平均粒径が２５ｎｍ以上である（もしくは、樹脂粒子１０１の平均粒径の１／１２０以上である）と、第１層１０４の突起１０９が適度な大きさになりやすく、低抵抗化する傾向がある。非導電性無機粒子１０２のゼータ電位は、粒径に応じて異なり、粒径が小さいほどゼータ電位がよりマイナス側にシフトすることが見出されている。このため、非導電性無機粒子１０２の平均粒径が１２０ｎｍ以下である（もしくは、樹脂粒子１０１の平均粒径の１／２５以下である）と、非導電性無機粒子１０２と樹脂粒子１０１との電位差が充分となり、第１層１０４を形成するとき等において当該非導電性無機粒子１０２が脱落しにくくなる。これにより、突起１０９の数が充分となり、低抵抗化しやすくなる傾向がある。脱落した非導電性無機粒子１０２が凝集したものに第１層１０４の金属が被覆し、金属異物が生成されることがある。この金属異物が樹脂粒子１０１に再付着し、異常析出部として過剰に長い突起（例えば、長さが５００ｎｍを超える突起）が形成されることがある。この場合、導電粒子１００ａの絶縁信頼性低下の要因となることがある。さらに、上記金属異物そのものが絶縁信頼性低下の要因となることがある。したがって、非導電性無機粒子１０２の樹脂粒子１０１からの脱落を抑制することが好ましい。非導電性無機粒子１０２の平均粒径は、３０～１１０ｎｍであってもよく、３５～１００ｎｍであってもよい。非導電性無機粒子１０２の粒径は、ＢＥＴ法による比表面積換算法又はＸ線小角散乱法により測定される。 When the average particle diameter of the non-conductive inorganic particles 102 is 25 nm or more (or 1/120 or more of the average particle diameter of the resin particles 101), the protrusions 109 of the first layer 104 are likely to have an appropriate size. , Tend to lower resistance. It has been found that the zeta potential of the non-conductive inorganic particles 102 varies depending on the particle size, and the zeta potential shifts more negatively as the particle size decreases. Therefore, when the average particle size of the non-conductive inorganic particles 102 is 120 nm or less (or 1/25 or less of the average particle size of the resin particles 101), the non-conductive inorganic particles 102 and the resin particles 101 The potential difference is sufficient, and the non-conductive inorganic particles 102 are less likely to drop off when the first layer 104 is formed. As a result, the number of protrusions 109 becomes sufficient, and the resistance tends to be reduced. In some cases, the metal of the first layer 104 covers the aggregated pieces of the non-conductive inorganic particles 102 that have fallen, and metal foreign matter may be generated. The metal foreign matter may reattach to the resin particles 101, and an excessively long protrusion (for example, a protrusion having a length exceeding 500 nm) may be formed as an abnormal precipitation portion. In this case, the insulation reliability of the conductive particles 100a may be reduced. Furthermore, the metal foreign matter itself may cause a decrease in insulation reliability. Therefore, it is preferable to prevent the non-conductive inorganic particles 102 from dropping from the resin particles 101. The average particle diameter of the non-conductive inorganic particles 102 may be 30 to 110 nm or 35 to 100 nm. The particle size of the non-conductive inorganic particles 102 is measured by a specific surface area conversion method by the BET method or a small-angle X-ray scattering method.
　「非導電性無機粒子１０２の直径」とは、非導電性無機粒子１０２の正投影面において、非導電性無機粒子１０２の面積と同一の面積を有する真円の直径を意味する。具体的には、非導電性無機粒子をＳＥＭにより１０万倍で観察して得られる画像を解析し、非導電性無機粒子の輪郭を画定する。そして、任意の非導電性無機粒子の面積を算出して、その面積から非導電性無機粒子１０２の直径を求める。 “The diameter of the non-conductive inorganic particles 102” means the diameter of a perfect circle having the same area as that of the non-conductive inorganic particles 102 on the orthographic projection surface of the non-conductive inorganic particles 102. Specifically, an image obtained by observing non-conductive inorganic particles with a SEM at a magnification of 100,000 is analyzed to define the outline of the non-conductive inorganic particles. Then, the area of any non-conductive inorganic particles is calculated, and the diameter of the non-conductive inorganic particles 102 is obtained from the area.
　「非導電性無機粒子１０２の平均粒径」とは、非導電性無機粒子１０２の正投影面において、非導電性無機粒子１０２の面積と同一の面積を有する真円の直径から算出した平均粒径を意味する。具体的には、非導電性無機粒子をＳＥＭにより１０万倍で観察して得られる画像を解析し、非導電性無機粒子の輪郭を画定する。そして、任意の非導電性無機粒子５００個の面積をそれぞれ算出して、その面積を円に換算した場合の直径から算出した平均粒径を非導電性無機粒子１０２の平均粒径とする。 The “average particle diameter of the non-conductive inorganic particles 102” is an average particle calculated from the diameter of a perfect circle having the same area as that of the non-conductive inorganic particles 102 on the orthographic projection surface of the non-conductive inorganic particles 102. Means diameter. Specifically, an image obtained by observing non-conductive inorganic particles with a SEM at a magnification of 100,000 is analyzed to define the outline of the non-conductive inorganic particles. And the area of 500 arbitrary nonelectroconductive inorganic particles is calculated, respectively, and the average particle diameter calculated from the diameter when the area is converted into a circle is defined as the average particle diameter of the nonconductive inorganic particles 102.
＜非導電性無機粒子の疎水化度＞
　メタノール滴定法による非導電性無機粒子１０２の疎水化度は、例えば、３０％以上である。この場合、非導電性無機粒子１０２は、静電気力により樹脂粒子１０１に強固に接着することが可能となる。上記疎水化度は、５０％以上であってもよく、６０％以上であってもよい。疎水化度が高いほど、非導電性無機粒子１０２のゼータ電位がよりマイナス側にシフトし、非導電性無機粒子１０２は、静電気力により樹脂粒子１０１に強固に接着することが可能となる。 <Hydrophobicity of non-conductive inorganic particles>
The degree of hydrophobicity of the non-conductive inorganic particles 102 by the methanol titration method is, for example, 30% or more. In this case, the nonconductive inorganic particles 102 can be firmly bonded to the resin particles 101 by electrostatic force. The degree of hydrophobicity may be 50% or more, or 60% or more. The higher the degree of hydrophobicity, the more the zeta potential of the nonconductive inorganic particles 102 shifts to the negative side, and the nonconductive inorganic particles 102 can be firmly bonded to the resin particles 101 by electrostatic force.
　メタノール滴定法とは、メタノールを使用して粉体の疎水化度を測定する方法である。例えば、まず５０ｍｌの水面上に、疎水化度を測定すべき粉体０．２ｇを浮遊させる。次に、水を静かに撹拌しながら水中にメタノールを少しずつ添加してゆく。メタノールは、例えば、ビュレットを用いて滴下する。次に、水面上の粉体が全て水中に没した時点でのメタノール使用量を測定する。そして、水とメタノールとの合計体積に対するメタノール体積の百分率を演算し、この値を粉体の疎水化度と算出する。 Methanol titration method is a method for measuring the degree of hydrophobicity of powder using methanol. For example, first, 0.2 g of a powder whose hydrophobicity is to be measured is suspended on a 50 ml water surface. Next, methanol is gradually added to the water while gently stirring the water. For example, methanol is dropped using a burette. Next, the amount of methanol used when the powder on the water surface is all immersed in water is measured. Then, the percentage of the methanol volume with respect to the total volume of water and methanol is calculated, and this value is calculated as the degree of hydrophobicity of the powder.
＜樹脂粒子への非導電性無機粒子の接着方法＞
　樹脂粒子１０１への非導電性無機粒子１０２の接着は、有機溶媒、又は、水と水溶性の有機溶媒との混合溶液を用いて行うことができる。使用できる水溶性の有機溶媒としては、メタノール、エタノール、プロパノール、アセトン、ジメチルホルムアミド、アセトニトリル等が挙げられる。有機溶媒のみを用いた場合、樹脂粒子１０１のゼータ電位はよりプラス側に、非導電性無機粒子１０２のゼータ電位はよりマイナス側にシフトする傾向にある。有機溶媒のみを用いた場合、有機溶媒と水との混合溶液を用いた場合よりも、樹脂粒子１０１と非導電性無機粒子１０２との電位差が大きくなる傾向にある。したがって、有機溶媒のみを用いた場合、非導電性無機粒子１０２は強い静電気力により樹脂粒子１０１に強固に接着する傾向にある。結果として、第１層１０４の形成時等に非導電性無機粒子１０２が樹脂粒子１０１から脱落しづらくなる。 <Adhesion method of non-conductive inorganic particles to resin particles>
Adhesion of the non-conductive inorganic particles 102 to the resin particles 101 can be performed using an organic solvent or a mixed solution of water and a water-soluble organic solvent. Examples of water-soluble organic solvents that can be used include methanol, ethanol, propanol, acetone, dimethylformamide, and acetonitrile. When only the organic solvent is used, the zeta potential of the resin particles 101 tends to shift to the plus side, and the zeta potential of the non-conductive inorganic particles 102 tends to shift to the minus side. When only the organic solvent is used, the potential difference between the resin particles 101 and the non-conductive inorganic particles 102 tends to be larger than when a mixed solution of the organic solvent and water is used. Therefore, when only the organic solvent is used, the non-conductive inorganic particles 102 tend to adhere firmly to the resin particles 101 with a strong electrostatic force. As a result, it is difficult for the non-conductive inorganic particles 102 to fall off the resin particles 101 when the first layer 104 is formed.
＜第１層＞
　第１層１０４は、ニッケルを主成分として含む導電層である。第１層１０４の厚さは、例えば、４０ｎｍ～２００ｎｍである。第１層１０４の厚さが上記範囲内であると、導電粒子１００ａが圧縮された場合であっても、第１層１０４の割れを抑制できる。また、複合粒子１０３の表面を第１層１０４により充分に被覆することができる。これにより、非導電性無機粒子１０２を樹脂粒子１０１に固着化させ、非導電性無機粒子１０２の脱落を抑制することが可能となる。この結果、得られる導電粒子１００ａの一つ一つに均一な形状の突起１０９を高密度に形成することが可能となる。第１層１０４の厚さは、６０ｎｍ以上でもよい。第１層１０４の厚さは、１５０ｎｍ以下でもよく、１２０ｎｍ以下でもよい。第１層１０４は、単層構造でもよいし、積層構造でもよい。本実施形態では、第１層１０４は２層構造を有する。 <First layer>
The first layer 104 is a conductive layer containing nickel as a main component. The thickness of the first layer 104 is, for example, 40 nm to 200 nm. When the thickness of the first layer 104 is within the above range, cracking of the first layer 104 can be suppressed even when the conductive particles 100a are compressed. Further, the surface of the composite particle 103 can be sufficiently covered with the first layer 104. As a result, the non-conductive inorganic particles 102 can be fixed to the resin particles 101, and the non-conductive inorganic particles 102 can be prevented from falling off. As a result, it is possible to form the protrusions 109 having a uniform shape with high density on each of the obtained conductive particles 100a. The thickness of the first layer 104 may be 60 nm or more. The thickness of the first layer 104 may be 150 nm or less, or 120 nm or less. The first layer 104 may have a single layer structure or a stacked structure. In the present embodiment, the first layer 104 has a two-layer structure.
　第１層１０４の厚さは、透過型電子顕微鏡（以下、「ＴＥＭ」という）によって撮影された写真を用いて算出される。具体例として、まず、導電粒子１００ａの中心付近を通るようにウルトラミクロトーム法で当該導電粒子１００ａの断面を切り出す。次に、切り出した断面を、ＴＥＭを用いて２５万倍の倍率で観察して画像を得る。次に、得られた画像から見積もられる第１層１０４（図２）の断面積から、第１層１０４の厚さを算出できる。このとき、第１層１０４、樹脂粒子１０１及び非導電性無機粒子１０２が区別しづらい場合には、ＴＥＭに付属するエネルギー分散型Ｘ線検出器（以下、「ＥＤＸ」という）による成分分析を行う。これにより、第１層１０４、樹脂粒子１０１及び非導電性無機粒子１０２を明確に区別し、第１層１０４のみの厚さを算出する。第１層１０４の厚さは、導電粒子１０個における厚さの平均値とする。 The thickness of the first layer 104 is calculated using a photograph taken with a transmission electron microscope (hereinafter referred to as “TEM”). As a specific example, first, a cross section of the conductive particle 100a is cut out by an ultramicrotome method so as to pass near the center of the conductive particle 100a. Next, the cut section is observed at a magnification of 250,000 times using a TEM to obtain an image. Next, the thickness of the first layer 104 can be calculated from the cross-sectional area of the first layer 104 (FIG. 2) estimated from the obtained image. At this time, if it is difficult to distinguish the first layer 104, the resin particles 101, and the non-conductive inorganic particles 102, component analysis is performed by an energy dispersive X-ray detector (hereinafter referred to as “EDX”) attached to the TEM. . Thereby, the first layer 104, the resin particles 101, and the non-conductive inorganic particles 102 are clearly distinguished, and the thickness of only the first layer 104 is calculated. The thickness of the first layer 104 is an average value of the thickness of 10 conductive particles.
　第１層１０４は、ニッケルを主成分とする金属に加えて、リン及びホウ素からなる群より選ばれる少なくとも一種を含有してもよい。これにより、ニッケルを含有する第１層１０４の硬度を高めることが可能であり、導電粒子が圧縮されたときの導通抵抗を容易に低く保つことができる。第１層１０４は、リン又はホウ素と共に、共析する金属を含有していてもよい。第１層１０４に含有される金属は、例えば、コバルト、銅、亜鉛、鉄、マンガン、クロム、バナジウム、モリブデン、パラジウム、錫、タングステン及びレニウムである。第１層１０４は、ニッケル及び上記金属を含有することによって、第１層１０４の硬度を高めることができる。これにより、導電粒子１００ａが圧縮された場合であっても、非導電性無機粒子１０２の上部に形成された部分（突起１０９）が押しつぶされることを抑制できる。上記金属は、高い硬度を有するタングステンを含んでもよい。第１層１０４の構成材料としては、例えば、ニッケル（Ｎｉ）及びリン（Ｐ）の組み合わせ、ニッケル（Ｎｉ）及びホウ素（Ｂ）の組み合わせ、ニッケル（Ｎｉ）、タングステン（Ｗ）及びホウ素（Ｂ）の組み合わせ、並びに、ニッケル（Ｎｉ）及びパラジウム（Ｐｄ）の組み合わせが好ましい。 The first layer 104 may contain at least one selected from the group consisting of phosphorus and boron in addition to the metal whose main component is nickel. Accordingly, the hardness of the first layer 104 containing nickel can be increased, and the conduction resistance when the conductive particles are compressed can be easily kept low. The first layer 104 may contain a eutectoid metal together with phosphorus or boron. The metal contained in the first layer 104 is, for example, cobalt, copper, zinc, iron, manganese, chromium, vanadium, molybdenum, palladium, tin, tungsten, and rhenium. The first layer 104 can increase the hardness of the first layer 104 by containing nickel and the above metal. Thereby, even if it is a case where the electroconductive particle 100a is compressed, it can suppress that the part (protrusion 109) formed in the upper part of the nonelectroconductive inorganic particle 102 is crushed. The metal may include tungsten having a high hardness. Examples of the constituent material of the first layer 104 include a combination of nickel (Ni) and phosphorus (P), a combination of nickel (Ni) and boron (B), nickel (Ni), tungsten (W), and boron (B). And a combination of nickel (Ni) and palladium (Pd).
　第１層１０４を後述する無電解ニッケルめっきにより形成する場合、例えば、還元剤として次亜リン酸ナトリウム等のリン含有化合物を用いてもよい。この場合、リンを共析させることが可能であり、ニッケル－リン合金を含有する第１層１０４を形成することができる。還元剤として、例えば、ジメチルアミンボラン、水素化ホウ素ナトリウム、水素化ホウ素カリウム等のホウ素含有化合物を用いてもよい。この場合、ホウ素を共析させることが可能であり、ニッケル－ホウ素合金を含有する第１層１０４を形成することができる。ニッケル－ホウ素合金の硬度はニッケル－リン合金よりも高い。そのため、還元剤としてホウ素含有化合物を用いた場合、導電粒子１００ａを圧縮した場合であっても非導電性無機粒子１０２の上部に形成された突起１０９が押しつぶされることを良好に抑制できる。 When the first layer 104 is formed by electroless nickel plating described later, for example, a phosphorus-containing compound such as sodium hypophosphite may be used as a reducing agent. In this case, phosphorus can be co-deposited, and the first layer 104 containing a nickel-phosphorus alloy can be formed. As the reducing agent, for example, boron-containing compounds such as dimethylamine borane, sodium borohydride, potassium borohydride and the like may be used. In this case, boron can be co-deposited, and the first layer 104 containing a nickel-boron alloy can be formed. The hardness of the nickel-boron alloy is higher than that of the nickel-phosphorus alloy. Therefore, when a boron-containing compound is used as the reducing agent, the protrusions 109 formed on the top of the non-conductive inorganic particles 102 can be satisfactorily suppressed even when the conductive particles 100a are compressed.
　第１層１０４は、複合粒子１０３の表面から遠ざかるにつれてニッケルの濃度（含有量）が高くなる濃度勾配を有してもよい。このような構成により、導電粒子１００ａが圧縮された場合であっても低い導通抵抗を保つことができる。この濃度勾配は、連続的であってもよく、非連続的であってもよい。ニッケルの濃度勾配が非連続的である場合、複合粒子１０３の表面に、第１層１０４としてニッケルの含有量が異なる複数の層を設けてもよい。この場合、複合粒子１０３から遠い側に設けられる層のニッケルの濃度が高くなる。 The first layer 104 may have a concentration gradient in which the nickel concentration (content) increases as the distance from the surface of the composite particle 103 increases. With such a configuration, a low conduction resistance can be maintained even when the conductive particles 100a are compressed. This concentration gradient may be continuous or discontinuous. When the concentration gradient of nickel is discontinuous, a plurality of layers having different nickel contents may be provided as the first layer 104 on the surface of the composite particle 103. In this case, the nickel concentration of the layer provided on the side far from the composite particle 103 is increased.
　第１層１０４におけるニッケルの含有量は、第１層１０４の厚さ方向において表面に近づくにつれて高くなる。第１層１０４の表面側の層におけるニッケルの含有量は、例えば、９９質量％～９７質量％になっている。上記表面側の層の厚さは、例えば、５～６０ｎｍである。当該層の厚さは、１０～５０ｎｍでもよく、１５～４０ｎｍでもよい。上記表面側の層の厚さが５ｎｍ以上である場合、第１層１０４の接続抵抗値が低くなる傾向にある。一方、表面側の層の厚さが６０ｎｍ以下である場合、導電粒子１００ａの単分散率がより向上する傾向にある。したがって、第１層１０４の表面側の層におけるニッケルの含有量が９９質量％～９７質量％になっており、且つ上記表面側の層の厚さが５～６０ｎｍである場合、第１層１０４をより低抵抗化しやすくなる。加えて、導電粒子１００ａ同士の凝集をより抑制して、高い絶縁信頼性を得やすくなる。 The nickel content in the first layer 104 increases as the surface approaches the surface in the thickness direction of the first layer 104. The nickel content in the surface layer of the first layer 104 is, for example, 99 mass% to 97 mass%. The thickness of the surface side layer is, for example, 5 to 60 nm. The thickness of the layer may be 10 to 50 nm or 15 to 40 nm. When the thickness of the layer on the surface side is 5 nm or more, the connection resistance value of the first layer 104 tends to be low. On the other hand, when the thickness of the surface layer is 60 nm or less, the monodispersion rate of the conductive particles 100a tends to be further improved. Accordingly, when the nickel content in the surface layer of the first layer 104 is 99 mass% to 97 mass% and the thickness of the surface layer is 5 to 60 nm, the first layer 104 It becomes easier to lower the resistance. In addition, aggregation of the conductive particles 100a is further suppressed, and high insulation reliability is easily obtained.
　第１層１０４の厚さ方向において複合粒子１０３側には、ニッケルの含有量が９７質量％以下である層が形成されていてもよい。この複合粒子１０３側の層のニッケルの含有料は、９５質量％以下でもよく、９４質量％以下でもよい。複合粒子１０３側の層の厚さは、２０ｎｍ以上でもよく、４０ｎｍ以上でもよく、５０ｎｍ以上でもよい。特に、第１層１０４の複合粒子１０３側に９４質量％以下の層を２０ｎｍ以上形成すると、導電粒子１００ａ同士は磁性の影響を受けにくくなり、当該導電粒子１００ａ同士の凝集が抑制される傾向にある。 In the thickness direction of the first layer 104, a layer having a nickel content of 97% by mass or less may be formed on the composite particle 103 side. The nickel content of the layer on the composite particle 103 side may be 95% by mass or less, or 94% by mass or less. The thickness of the layer on the composite particle 103 side may be 20 nm or more, 40 nm or more, or 50 nm or more. In particular, when a layer of 94% by mass or less is formed on the composite particle 103 side of the first layer 104 by 20 nm or more, the conductive particles 100a are not easily affected by magnetism, and aggregation of the conductive particles 100a tends to be suppressed. is there.
　第１層１０４における元素の種類及び当該元素の含有量は、例えば、ウルトラミクロトーム法で導電粒子の断面を切り出した後、ＴＥＭに付属するＥＤＸによって成分分析を行うことによって測定できる。 The kind of element and the content of the element in the first layer 104 can be measured by, for example, cutting out a cross section of the conductive particle by an ultramicrotome method and then performing component analysis by EDX attached to the TEM.
＜無電解ニッケルめっき＞
　本実施形態においては、第１層１０４は、無電解ニッケルめっきにより形成される。この場合、無電解ニッケルめっき液は、水溶性ニッケル化合物を含む。無電解ニッケルめっき液は、安定剤（例えば、硝酸ビスマス）、錯化剤、還元剤、ｐＨ調整剤及び界面活性剤からなる群より選択される少なくとも一種の化合物を更に含んでもよい。 <Electroless nickel plating>
In the present embodiment, the first layer 104 is formed by electroless nickel plating. In this case, the electroless nickel plating solution contains a water-soluble nickel compound. The electroless nickel plating solution may further contain at least one compound selected from the group consisting of a stabilizer (for example, bismuth nitrate), a complexing agent, a reducing agent, a pH adjusting agent, and a surfactant.
　水溶性ニッケル化合物としては、硫酸ニッケル、塩化ニッケル、次亜リン酸ニッケル等の水溶性ニッケル無機塩；酢酸ニッケル、リンゴ酸ニッケル等の水溶性ニッケル有機塩などが用いられる。水溶性ニッケル化合物は、一種を単独で又は二種以上を組み合わせて用いることができる。 As the water-soluble nickel compound, water-soluble nickel inorganic salts such as nickel sulfate, nickel chloride and nickel hypophosphite; water-soluble nickel organic salts such as nickel acetate and nickel malate are used. A water-soluble nickel compound can be used individually by 1 type or in combination of 2 or more types.
　無電解ニッケルめっき液における水溶性ニッケル化合物の濃度は、０．００１～１ｍｏｌ／Ｌが好ましく、０．０１～０．３ｍｏｌ／Ｌがより好ましい。水溶性ニッケル化合物の濃度が上記範囲内であることで、めっき被膜の析出速度を充分に得ることができると共に、めっき液の粘度が高くなりすぎることを抑制してニッケル析出の均一性を高めることができる。 The concentration of the water-soluble nickel compound in the electroless nickel plating solution is preferably 0.001 to 1 mol / L, and more preferably 0.01 to 0.3 mol / L. When the concentration of the water-soluble nickel compound is within the above range, it is possible to sufficiently obtain the deposition rate of the plating film, and to suppress the viscosity of the plating solution from becoming too high, thereby improving the uniformity of nickel deposition. Can do.
　錯化剤としては、錯化剤として機能するものであればよく、具体的には、エチレンジアミンテトラ酢酸；エチレンジアミンテトラ酢酸のナトリウム塩（例えば、１－，２－，３－及び４－ナトリウム塩）；エチレンジアミントリ酢酸；ニトロテトラ酢酸、そのアルカリ塩；グリコン酸、酒石酸、グルコネート、クエン酸、グルコン酸、コハク酸、ピロリン酸、グリコール酸、乳酸、リンゴ酸、マロン酸、これらのアルカリ塩（例えば、ナトリウム塩）；トリエタノールアミングルコノ（γ）－ラクトン等が挙げられる。錯化剤は、上記以外の材料を用いてもよい。錯化剤は、一種を単独で又は二種以上を組み合わせて用いることができる。 Any complexing agent may be used as long as it functions as a complexing agent. Specifically, ethylenediaminetetraacetic acid; sodium salt of ethylenediaminetetraacetic acid (for example, 1-, 2-, 3- and 4-sodium salts) Ethylenediaminetriacetic acid; nitrotetraacetic acid, alkali salts thereof; glyconic acid, tartaric acid, gluconate, citric acid, gluconic acid, succinic acid, pyrophosphoric acid, glycolic acid, lactic acid, malic acid, malonic acid, alkali salts thereof (for example, sodium Salt); triethanolamine glucono (γ) -lactone and the like. As the complexing agent, materials other than those described above may be used. A complexing agent can be used individually by 1 type or in combination of 2 or more types.
　無電解ニッケルめっき液における錯化剤の濃度は、通常、０．００１～２ｍｏｌ／Ｌが好ましく、０．００２～１ｍｏｌ／Ｌがより好ましい。錯化剤の濃度が上記範囲内であることで、めっき液中の水酸化ニッケルの沈殿及びめっき液の分解を抑制しつつめっき被膜の充分な析出速度を得ることができると共に、めっき液の粘度が高くなりすぎることを抑制してニッケル析出の均一性を高めることができる。錯化剤の濃度は、種類によって異なってもよい。 The concentration of the complexing agent in the electroless nickel plating solution is usually preferably 0.001 to 2 mol / L, and more preferably 0.002 to 1 mol / L. When the concentration of the complexing agent is within the above range, it is possible to obtain a sufficient deposition rate of the plating film while suppressing precipitation of nickel hydroxide in the plating solution and decomposition of the plating solution, and the viscosity of the plating solution. Can be prevented from becoming too high, and the uniformity of nickel deposition can be improved. The concentration of the complexing agent may vary depending on the type.
　還元剤としては、無電解ニッケルめっき液に用いられる公知の還元剤を用いることができる。還元剤としては、次亜リン酸ナトリウム、次亜リン酸カリウム等の次亜リン酸化合物；水素化ホウ素ナトリウム、水素化ホウ素カリウム、ジメチルアミンボラン等の水素化ホウ素化合物；ヒドラジン類などが挙げられる。 As the reducing agent, a known reducing agent used for an electroless nickel plating solution can be used. Examples of the reducing agent include hypophosphite compounds such as sodium hypophosphite and potassium hypophosphite; borohydride compounds such as sodium borohydride, potassium borohydride and dimethylamine borane; hydrazines and the like. .
　無電解ニッケルめっき液における還元剤の濃度は、通常、０．００１～１ｍｏｌ／Ｌが好ましく、０．００２～０．５ｍｏｌ／Ｌがより好ましい。還元剤の濃度が上記範囲内であると、めっき液中でのニッケルイオンの還元速度を充分に得つつ、めっき液の分解を抑制することができる。還元剤の濃度については、還元剤の種類によっても異なってもよい。 The concentration of the reducing agent in the electroless nickel plating solution is usually preferably 0.001 to 1 mol / L, and more preferably 0.002 to 0.5 mol / L. When the concentration of the reducing agent is within the above range, decomposition of the plating solution can be suppressed while sufficiently obtaining a nickel ion reduction rate in the plating solution. The concentration of the reducing agent may vary depending on the type of the reducing agent.
　ｐＨ調整剤としては、例えば、酸性のｐＨ調整剤及びアルカリ性のｐＨ調整剤が挙げられる。酸性のｐＨ調整剤としては、塩酸；硫酸；硝酸；リン酸；酢酸；ギ酸；塩化第２銅；硫酸第２鉄等の鉄化合物；アルカリ金属塩化物；過硫酸アンモニウム；これらを１種以上含む水溶液；クロム酸、クロム酸－硫酸、クロム酸－フッ酸、重クロム酸、重クロム酸－ホウフッ酸等の酸性の６価クロムを含む水溶液などが挙げられる。アルカリ性のｐＨ調整剤としては、水酸化ナトリウム、水酸化カリウム、炭酸ナトリウム等のアルカリ金属の水酸化物；アルカリ土類金属の水酸化物；エチレンジアミン、メチルアミン、２－アミノエタノール等のアミノ基を含有する化合物；これらを１種以上含む溶液などが挙げられる。 Examples of the pH adjuster include an acidic pH adjuster and an alkaline pH adjuster. Acidic pH adjusters include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, formic acid, cupric chloride, iron compounds such as ferric sulfate, alkali metal chlorides, ammonium persulfate, and aqueous solutions containing one or more of these. An aqueous solution containing acidic hexavalent chromium such as chromic acid, chromic acid-sulfuric acid, chromic acid-hydrofluoric acid, dichromic acid, dichromic acid-borofluoric acid, and the like. Examples of alkaline pH adjusters include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and sodium carbonate; alkaline earth metal hydroxides; amino groups such as ethylenediamine, methylamine, and 2-aminoethanol. Compounds containing; solutions containing one or more of these may be mentioned.
　界面活性剤としては、カチオン界面活性剤、アニオン界面活性剤、両性界面活性剤、非イオン界面活性剤、これらの混合物等を用いることができる。 As the surfactant, a cationic surfactant, an anionic surfactant, an amphoteric surfactant, a nonionic surfactant, a mixture thereof, or the like can be used.
＜無電解ニッケルめっきの前処理＞
　第１層１０４を上述した無電解ニッケルめっきにより形成する場合、複合粒子１０３に対して予め前処理としてパラジウム触媒化処理してもよい。パラジウム触媒化処理は、公知の方法で行うことができる。その方法は特に限定されないが、例えば、アルカリシーダ又は酸性シーダと呼ばれる触媒化処理液を用いた触媒化処理方法が挙げられる。 <Pretreatment of electroless nickel plating>
When the first layer 104 is formed by the electroless nickel plating described above, the composite particles 103 may be preliminarily treated with a palladium catalyst. The palladium catalyst treatment can be performed by a known method. The method is not particularly limited, and examples thereof include a catalytic treatment method using a catalytic treatment liquid called an alkali seeder or an acidic seeder.
　アルカリシーダを用いた触媒化処理方法としては、例えば、以下の方法が挙げられる。まず、２－アミノピリジンが配位したパラジウムイオンを含む溶液に樹脂粒子を浸漬させることで樹脂粒子表面にパラジウムイオンを吸着させる。水洗後、パラジウムイオンが吸着した樹脂粒子を、次亜リン酸ナトリウム、水素化ホウ素ナトリウム、ジメチルアミンボラン、ヒドラジン、ホルマリン等の還元剤を含む溶液中に分散させて還元処理を行う。これにより、樹脂粒子表面に吸着したパラジウムイオンを金属のパラジウムに還元する。 Examples of the catalyst treatment method using an alkali seeder include the following methods. First, by immersing resin particles in a solution containing palladium ions coordinated with 2-aminopyridine, the palladium ions are adsorbed on the surface of the resin particles. After washing with water, the resin particles adsorbed with palladium ions are dispersed in a solution containing a reducing agent such as sodium hypophosphite, sodium borohydride, dimethylamine borane, hydrazine, formalin and the like to perform a reduction treatment. Thus, palladium ions adsorbed on the surface of the resin particles are reduced to metallic palladium.
　酸性シーダを用いた触媒化処理方法としては、例えば、以下の方法が挙げられる。まず、樹脂粒子を塩化第一錫溶液に分散させ、錫イオンを樹脂粒子表面に吸着させる感受性化処理を行った後、水洗する。次に、塩化パラジウムを含む溶液に分散させ、パラジウムイオンを樹脂粒子表面に捕捉させる活性化処理を行う。水洗後、次亜リン酸ナトリウム、水素化ホウ素ナトリウム、ジメチルアミンボラン、ヒドラジン、ホルマリン等の還元剤を含む溶液中に分散させて還元処理を行う。これにより、樹脂粒子表面に吸着したパラジウムイオンを金属のパラジウムに還元する。 Examples of the catalytic treatment method using an acidic seeder include the following methods. First, the resin particles are dispersed in a stannous chloride solution and subjected to a sensitization treatment in which tin ions are adsorbed on the surface of the resin particles, and then washed with water. Next, an activation treatment is performed in which the solution is dispersed in a solution containing palladium chloride to trap palladium ions on the surface of the resin particles. After washing with water, reduction treatment is performed by dispersing in a solution containing a reducing agent such as sodium hypophosphite, sodium borohydride, dimethylamine borane, hydrazine, formalin and the like. Thus, palladium ions adsorbed on the surface of the resin particles are reduced to metallic palladium.
　アルカリシーダと酸性シーダとを比較すると、溶液のｐＨの観点から酸性シーダの方が好ましい。上述したように、樹脂粒子１０１そのもののゼータ電位は、ｐＨが低い程プラスにシフトするので、酸性シーダの使用が好ましい。一方、非導電性無機粒子１０２のゼータ電位は、ｐＨが高いほどマイナスにシフトするので、アルカリシーダの使用が好ましい。ここで、樹脂粒子１０１と非導電性無機粒子１０２とのゼータ電位の差を考慮すると、ｐＨが低いほどゼータ電位の差が大きくなる傾向にある。酸性シーダを使用することにより、非導電性無機粒子１０２を静電気力により樹脂粒子１０１に強固に接着された状態を維持できる傾向にある。 When comparing the alkali seeder and the acidic seeder, the acidic seeder is preferable from the viewpoint of the pH of the solution. As described above, since the zeta potential of the resin particle 101 itself shifts to a plus as the pH is lower, it is preferable to use an acidic seeder. On the other hand, since the zeta potential of the non-conductive inorganic particles 102 shifts to negative as the pH increases, it is preferable to use an alkali seeder. Here, considering the difference in zeta potential between the resin particles 101 and the non-conductive inorganic particles 102, the difference in zeta potential tends to increase as the pH decreases. By using an acidic seeder, the non-conductive inorganic particles 102 tend to be maintained firmly bonded to the resin particles 101 by electrostatic force.
　アルカリシーダを使用する場合、疎水化処理剤にアミノ基、カルボン酸基、水酸基、スルフォン酸基、グリシジル基、及びニトリル基からなる群から選ばれる少なくとも一種を有していることが好ましい。例えば、カルボン酸基及び水酸基のＨ＋は、ｐＨ７以上において解離し、非導電性無機粒子１０２のゼータ電位は、よりマイナス側にシフトする。ただし、樹脂粒子１０１のゼータ電位もｐＨにより変動するため、樹脂粒子１０１と非導電性無機粒子１０２とのゼータ電位の差が大きく保てるように、シーダの種類を選ぶことが好ましい。 When using an alkali seeder, the hydrophobizing agent preferably has at least one selected from the group consisting of an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, and a nitrile group. For example, the H + of the carboxylic acid group and the hydroxyl group is dissociated at a pH of 7 or higher, and the zeta potential of the non-conductive inorganic particles 102 is shifted to the minus side. However, since the zeta potential of the resin particles 101 also varies depending on the pH, it is preferable to select the type of seeder so that the difference in zeta potential between the resin particles 101 and the non-conductive inorganic particles 102 can be kept large.
　これらのパラジウム触媒化処理方法では、パラジウムイオンを表面に吸着させた後に水洗し、さらに、還元剤を含む溶液に分散させる。これにより、複合粒子１０３の表面に吸着したパラジウムイオンを還元することにより、原子レベルの大きさのパラジウム析出核を形成することができる。 In these palladium catalyzed treatment methods, palladium ions are adsorbed on the surface, washed with water, and further dispersed in a solution containing a reducing agent. Thus, palladium precipitation nuclei having an atomic level can be formed by reducing palladium ions adsorbed on the surface of the composite particle 103.
＜突起＞
　導電粒子１００ａにおける突起１０９の面積は、導電粒子１００ａの正投影面において、導電粒子１００ａの直径の１／２の直径を有する同心円内の突起１０９の面積、もしくは、隣接する突起１０９同士の間の谷により区切られる各突起１０９の輪郭の面積を意味する。突起１０９の直径（外径）は、導電粒子１００ａの正投影面において、導電粒子１００ａの直径の１／２の直径を有する同心円内に存在する突起１０９について算出され、当該突起１０９の面積と同一の面積を有する真円の直径を意味する。具体的には、導電粒子１００ａをＳＥＭにより３万倍で観察して得られる画像を解析し、突起１０９の輪郭を画定することにより、各突起の面積を求める。そしてこの面積から直径を算出する。 <Protrusions>
The area of the protrusion 109 in the conductive particle 100a is the area of the protrusion 109 in a concentric circle having a diameter that is ½ of the diameter of the conductive particle 100a on the orthographic projection surface of the conductive particle 100a, or between adjacent protrusions 109. It means the area of the outline of each protrusion 109 delimited by a valley. The diameter (outer diameter) of the protrusion 109 is calculated for the protrusion 109 existing in a concentric circle having a diameter ½ of the diameter of the conductive particle 100a on the orthographic projection surface of the conductive particle 100a, and is the same as the area of the protrusion 109. The diameter of a perfect circle having an area of Specifically, an image obtained by observing the conductive particles 100a by 30,000 times with an SEM is analyzed, and the contour of the protrusion 109 is defined to obtain the area of each protrusion. Then, the diameter is calculated from this area.
　突起１０９の面積の割合（被覆率）は、導電粒子１００ａの正投影面において、導電粒子１００ａの直径の１／２の直径を有する同心円の全面積を分母とし、導電粒子１００ａの直径の１／２の直径を有する同心円内の突起１０９の面積の総和を分子として割り出された１００分率で示すことができる。突起１０９の面積の割合（被覆率）は、５０％以上でもよく、６５％以上でもよく、８０％以上でもよい。突起１０９による被覆率が上記範囲内であると、導電粒子１００ａが高湿下におかれた場合であっても、その導通抵抗が増加しにくくなる。 The ratio (coverage) of the area of the protrusion 109 is 1 / of the diameter of the conductive particle 100a with the total area of concentric circles having a diameter that is 1/2 the diameter of the conductive particle 100a on the orthographic projection surface of the conductive particle 100a. The sum of the areas of the protrusions 109 in the concentric circles having a diameter of 2 can be expressed as a 100-percent fraction calculated as a numerator. The area ratio (coverage) of the protrusions 109 may be 50% or more, 65% or more, or 80% or more. When the coverage by the protrusions 109 is within the above range, even when the conductive particles 100a are placed under high humidity, the conduction resistance is unlikely to increase.
　突起１０９の最適な直径（外径）の大きさと、突起１０９による被覆率の最適な割合とは、樹脂粒子１０１及び非導電性無機粒子１０２の直径の大きさによって異なる。いずれの非導電性無機粒子１０２を用いても、非導電性無機粒子１０２による樹脂粒子１０１の被覆率を２０～８０％とすることで、突起１０９による被覆率を５０％以上にすることが可能である。 The optimal diameter (outer diameter) of the protrusion 109 and the optimal ratio of the coverage with the protrusion 109 differ depending on the diameter of the resin particles 101 and the non-conductive inorganic particles 102. Regardless of which non-conductive inorganic particles 102 are used, the coverage of the resin particles 101 by the non-conductive inorganic particles 102 can be set to 20 to 80%, so that the coverage by the protrusions 109 can be 50% or more. It is.
　非導電性無機粒子１０２の平均粒径が５０ｎｍ未満の場合、導電粒子１００ａ一つあたりにおいて、直径（外径）が１００ｎｍ未満の突起１０９の割合が全突起数に対し８０％未満であってもよく、直径が１００ｎｍ以上２００ｎｍ未満の突起１０９の割合が全突起数に対し２０～８０％であってもよく、直径が２００ｎｍ以上の突起１０９の割合が全突起数に対し２０％未満であってもよい。導電粒子１００ａ一つあたりにおいて、直径が１００ｎｍ未満の突起１０９の割合が全突起数に対し７０％未満であってもよく、直径が１００ｎｍ以上２００ｎｍ未満の突起１０９の割合が全突起数に対し３０～７０％であってもよく、直径が２００ｎｍ以上の突起１０９の割合が全突起数に対し１５％未満であってもよい。導電粒子１００ａ一つあたりにおいて、直径（外径）が１００ｎｍ未満の突起１０９の数は、５０個以上でもよく、８０個以上でもよい。導電粒子１００ａ一つあたりにおいて、直径が１００ｎｍ以上２００ｎｍ未満の突起１０９の数は、３０個以上でもよく、５０個以上でもよい。導電粒子１００ａ一つあたりにおいて、直径が２００ｎｍ以上３５０ｎｍ以下の突起１０９の数は、１５個以内でもよく、２個から１３個以内でもよく、２個から１０個以内でもよい。 When the average particle diameter of the non-conductive inorganic particles 102 is less than 50 nm, the ratio of the protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a is less than 80% of the total number of protrusions. The ratio of protrusions 109 having a diameter of 100 nm or more and less than 200 nm may be 20 to 80% of the total number of protrusions, and the ratio of protrusions 109 having a diameter of 200 nm or more is less than 20% of the total number of protrusions. Also good. Per conductive particle 100a, the ratio of protrusions 109 having a diameter of less than 100 nm may be less than 70% of the total number of protrusions, and the ratio of protrusions 109 having a diameter of 100 nm or more and less than 200 nm is 30% of the total number of protrusions. The ratio of protrusions 109 having a diameter of 200 nm or more may be less than 15% with respect to the total number of protrusions. In each conductive particle 100a, the number of protrusions 109 having a diameter (outer diameter) of less than 100 nm may be 50 or more, or 80 or more. The number of protrusions 109 having a diameter of 100 nm or more and less than 200 nm per conductive particle 100a may be 30 or more, or 50 or more. The number of protrusions 109 having a diameter of 200 nm or more and 350 nm or less per conductive particle 100a may be 15 or less, 2 to 13 or 2 to 10 or less.
　非導電性無機粒子１０２の平均粒径が５０ｎｍ以上９０ｎｍ未満の場合、導電粒子１００ａ一つあたりにおいて、直径（外径）が１００ｎｍ未満の突起１０９の割合が全突起数に対し７０％未満であってもよく、直径が１００ｎｍ以上２００ｎｍ未満の突起１０９の割合が全突起数に対し２０～８０％であってもよく、直径が２００ｎｍ以上の突起１０９の割合が全突起数に対し２０％未満であってもよい。導電粒子１００ａ一つあたりにおいて、直径が１００ｎｍ未満の突起１０９の割合が全突起数に対し６０％未満であってもよく、直径が１００ｎｍ以上２００ｎｍ未満の突起１０９の割合が全突起数に対し３０～７０％であってもよく、直径が２００ｎｍ以上の突起１０９の割合が全突起数に対し１５％未満であってもよい。導電粒子１００ａ一つあたりにおいて、直径（外径）が１００ｎｍ未満の突起１０９の数は、３０個以上でもよく、５０個以上でもよい。導電粒子１００ａ一つあたりにおいて、直径が１００ｎｍ以上２００ｎｍ未満の突起１０９の数は、３０個以上でもよく、５０個以上でもよい。導電粒子１００ａ一つあたりにおいて、直径が２００ｎｍ以上３５０ｎｍ以下の突起１０９の数は、１５個以内でもよく、２個から１３個以内でもよく、２個から１０個以内であってもよい。 When the average particle diameter of the non-conductive inorganic particles 102 is 50 nm or more and less than 90 nm, the ratio of the protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a is less than 70% of the total number of protrusions. The ratio of the protrusions 109 having a diameter of 100 nm or more and less than 200 nm may be 20 to 80% of the total number of protrusions, and the ratio of the protrusions 109 having a diameter of 200 nm or more is less than 20% of the total number of protrusions. There may be. Per conductive particle 100a, the ratio of protrusions 109 having a diameter of less than 100 nm may be less than 60% of the total number of protrusions, and the ratio of protrusions 109 having a diameter of 100 nm to less than 200 nm may be 30% of the total number of protrusions. The ratio of protrusions 109 having a diameter of 200 nm or more may be less than 15% with respect to the total number of protrusions. The number of protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a may be 30 or more, or 50 or more. The number of protrusions 109 having a diameter of 100 nm or more and less than 200 nm per conductive particle 100a may be 30 or more, or 50 or more. The number of protrusions 109 having a diameter of 200 nm or more and 350 nm or less per conductive particle 100a may be 15 or less, 2 to 13 or 2 to 10 or less.
　非導電性無機粒子１０２の平均粒径が９０ｎｍ以上１３０ｎｍ未満の場合、導電粒子１００ａ一つあたりにおいて、直径（外径）が１００ｎｍ未満の突起１０９の割合が全突起数に対し７０％未満であってもよく、直径が１００ｎｍ以上２００ｎｍ未満の突起１０９の割合が全突起数に対し２０～９０％であってもよく、直径が２００ｎｍ以上の突起１０９の割合が全突起数に対し７０％未満であってもよい。さらに、導電粒子１００ａ一つあたりにおいて、直径が１００ｎｍ未満の突起１０９の割合が全突起数に対し６０％未満であってもよく、直径が１００ｎｍ以上２００ｎｍ未満の突起１０９の割合が全突起数に対し３０～８０％であってもよく、直径が２００ｎｍ以上の突起１０９の割合が全突起数に対し５０％未満でもよい。導電粒子１００ａ一つあたりにおいて、直径（外径）が１００ｎｍ未満の突起１０９の数は、３０個以上でもよく、５０個以上でもよい。導電粒子１００ａ一つあたりにおいて、直径が１００ｎｍ以上２００ｎｍ未満の突起１０９の数は、３０個以上でもよく、５０個以上でもよい。導電粒子１００ａ一つあたりにおいて、直径が２００ｎｍ以上３５０ｎｍ以下の突起１０９の数は、１５個以内でもよく、２個から１３個以内でもよく、２個から１０個以内でもよい。 When the average particle diameter of the non-conductive inorganic particles 102 is 90 nm or more and less than 130 nm, the ratio of the protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a is less than 70% of the total number of protrusions. The ratio of the protrusions 109 having a diameter of 100 nm or more and less than 200 nm may be 20 to 90% of the total number of protrusions, and the ratio of the protrusions 109 having a diameter of 200 nm or more may be less than 70% of the total number of protrusions. There may be. Furthermore, in each conductive particle 100a, the ratio of the protrusions 109 having a diameter of less than 100 nm may be less than 60% with respect to the total number of protrusions, and the ratio of the protrusions 109 having a diameter of 100 nm to less than 200 nm is the total number of protrusions. The ratio of the protrusions 109 having a diameter of 200 nm or more may be less than 50% with respect to the total number of protrusions. The number of protrusions 109 having a diameter (outer diameter) of less than 100 nm per conductive particle 100a may be 30 or more, or 50 or more. The number of protrusions 109 having a diameter of 100 nm or more and less than 200 nm per conductive particle 100a may be 30 or more, or 50 or more. The number of protrusions 109 having a diameter of 200 nm or more and 350 nm or less per conductive particle 100a may be 15 or less, 2 to 13 or 2 to 10 or less.
　非導電性無機粒子１０２の平均粒径に応じた突起の数が上記範囲内である場合、例えば、相対向する電極間に導電粒子１００ａを介在させて電極同士を圧着接続したとき、充分低い導通抵抗を得ることができる。 When the number of protrusions corresponding to the average particle size of the non-conductive inorganic particles 102 is within the above range, for example, when the electrodes are crimped together with the conductive particles 100a interposed between the opposing electrodes, the conductivity is sufficiently low. Resistance can be obtained.
＜導電粒子の単分散率＞
　導電粒子１００ａの単分散率は、９６．０％以上でもよく、９８．０％以上であってもよい。導電粒子１００ａの単分散率が上記範囲内であることにより、例えば、吸湿試験後において高い絶縁信頼性を得ることができる。導電粒子１００ａの単分散率は、例えば、５０，０００個の導電粒子を用いて、ＣＯＵＬＥＲ　ＭＵＬＴＩＳＩＺＥＲ　ＩＩ（ベックマン・コールター株式会社製、商品名）により測定することができる。 <Monodispersion rate of conductive particles>
The monodispersion rate of the conductive particles 100a may be 96.0% or more, or 98.0% or more. When the monodispersion rate of the conductive particles 100a is within the above range, for example, high insulation reliability can be obtained after a moisture absorption test. The monodispersion rate of the conductive particles 100a can be measured by, for example, COULER MULTISIZER II (trade name, manufactured by Beckman Coulter, Inc.) using 50,000 conductive particles.
＜導電粒子の製造方法＞
　次に、第１実施形態に係る導電粒子１００ａの製造方法を説明する。まず、第１工程として、樹脂粒子１０１をカチオン性ポリマーによって被覆する（第１被覆工程）。第１工程では、水酸基等を表面に有する樹脂粒子１０１をカチオン性ポリマー溶液中に分散することにより、当該樹脂粒子１０１をカチオン性ポリマーにて被覆する。 <Method for producing conductive particles>
Next, a method for manufacturing the conductive particles 100a according to the first embodiment will be described. First, as a first step, the resin particles 101 are coated with a cationic polymer (first coating step). In the first step, resin particles 101 having a hydroxyl group or the like on the surface thereof are dispersed in a cationic polymer solution to coat the resin particles 101 with a cationic polymer.
　次に、第２工程として、非導電性無機粒子１０２の表面を疎水化処理剤によって被覆する（第２被覆工程）。疎水化処理剤による非導電性無機粒子１０２の被覆は、水、有機溶媒、もしくは、水と水溶性の有機溶媒との混合溶液中、又は、気相中にて行われる。使用できる水溶性の有機溶媒としては、例えば、メタノール、エタノール、プロパノール、アセトン、ジメチルホルムアミド及びアセトニトリルが挙げられる。疎水化処理剤があらかじめ被覆された非導電性無機粒子を購入し、非導電性無機粒子１０２として使用してもよい。 Next, as a second step, the surface of the non-conductive inorganic particles 102 is coated with a hydrophobizing agent (second coating step). The non-conductive inorganic particles 102 are coated with the hydrophobizing agent in water, an organic solvent, a mixed solution of water and a water-soluble organic solvent, or in a gas phase. Examples of water-soluble organic solvents that can be used include methanol, ethanol, propanol, acetone, dimethylformamide, and acetonitrile. Non-conductive inorganic particles coated with a hydrophobic treatment agent in advance may be purchased and used as the non-conductive inorganic particles 102.
　次に、第３工程として、樹脂粒子１０１の表面に非導電性無機粒子１０２を接着し、複合粒子１０３を形成する（粒子形成工程）。樹脂粒子１０１への非導電性無機粒子１０２の接着は、例えば、有機溶媒、又は、水と水溶性の有機溶媒との混合溶液により処理を行う。有機溶媒のみを用いて非導電性無機粒子１０２を樹脂粒子１０１に接着させることが好ましい。樹脂粒子１０１と非導電性無機粒子１０２とのゼータ電位の差を考慮すると、水を含んだ有機溶媒を用いる場合よりも、有機溶媒のみを用いた場合のほうが、非導電性無機粒子１０２と樹脂粒子１０１とのゼータ電位の差は大きくなる。非導電性無機粒子１０２と樹脂粒子１０１との間により強い静電気力が働くと、非導電性無機粒子１０２が樹脂粒子１０１に強固に接着することが可能となる。結果として、無電解ニッケルめっきを行うための前処理工程、及び無電解ニッケルめっき工程において、非導電性無機粒子１０２が脱落しづらくなる。 Next, as a third step, non-conductive inorganic particles 102 are bonded to the surface of the resin particles 101 to form composite particles 103 (particle formation step). Adhesion of the non-conductive inorganic particles 102 to the resin particles 101 is performed using, for example, an organic solvent or a mixed solution of water and a water-soluble organic solvent. It is preferable to adhere the nonconductive inorganic particles 102 to the resin particles 101 using only an organic solvent. In consideration of the difference in zeta potential between the resin particles 101 and the non-conductive inorganic particles 102, the non-conductive inorganic particles 102 and the resin are better when only the organic solvent is used than when the organic solvent containing water is used. The difference in zeta potential with the particle 101 increases. When a stronger electrostatic force acts between the non-conductive inorganic particles 102 and the resin particles 101, the non-conductive inorganic particles 102 can be firmly bonded to the resin particles 101. As a result, in the pretreatment process for performing electroless nickel plating and the electroless nickel plating process, the nonconductive inorganic particles 102 are difficult to drop off.
　次に、第４工程として、無電解めっきにより複合粒子１０３を金属層によって被覆する（第３被覆工程）。第４工程では、ニッケルを含有する第１層１０４を金属層とし、当該第１層１０４によって複合粒子１０３の表面全体（すなわち、樹脂粒子１０１及び非導電性無機粒子１０２の露出する面全体）を被覆する。この場合、第１層１０４を無電解ニッケルめっきにより形成するための前処理工程として、複合粒子１０３に対してパラジウム触媒化処理を行ってもよい。パラジウム触媒化処理は、公知の方法で行うことができ、例えば、上述したアルカリシーダ又は酸性シーダと呼ばれる触媒化処理液を用いた触媒化処理方法にて行われる。あらかじめ、樹脂粒子１０１の表面に非導電性無機粒子１０２を配置しても、周囲のｐＨの影響を受けて、樹脂粒子１０１と非導電性無機粒子１０２とのゼータ電位は変化する。 Next, as a fourth step, the composite particles 103 are coated with a metal layer by electroless plating (third coating step). In the fourth step, the first layer 104 containing nickel is used as a metal layer, and the entire surface of the composite particles 103 (that is, the entire surface where the resin particles 101 and the nonconductive inorganic particles 102 are exposed) is formed by the first layer 104. Cover. In this case, as a pretreatment process for forming the first layer 104 by electroless nickel plating, the composite particles 103 may be subjected to a palladium catalyst treatment. The palladium catalyst treatment can be performed by a known method, for example, by a catalyst treatment method using a catalyst treatment solution called an alkali seeder or an acid seeder described above. Even if the non-conductive inorganic particles 102 are arranged on the surface of the resin particles 101 in advance, the zeta potential of the resin particles 101 and the non-conductive inorganic particles 102 changes due to the influence of the surrounding pH.
　酸性シーダを用いた場合、触媒化処理液のｐＨが１程度になる。この場合、樹脂粒子１０１のゼータ電位の測定値と、非導電性無機粒子１０２のゼータ電位の測定値との差の絶対値は５０ｍＶ以上になる。このため、疎水化処理剤が被覆された非導電性無機粒子１０２が脱落しづらくなる。一方、一般的に使用されるアルカリシーダを用いた場合、触媒化処理液のｐＨが１０～１１になる。この場合、樹脂粒子１０１のゼータ電位の測定値と、非導電性無機粒子１０２のゼータ電位の測定値との差の絶対値は３０～５０ｍＶ程度になる。このため、上記前処理工程において、非導電性無機粒子１０２が樹脂粒子１０１から脱落しやすくなる。 When an acidic seeder is used, the pH of the catalyzed solution becomes about 1. In this case, the absolute value of the difference between the measured value of the zeta potential of the resin particles 101 and the measured value of the zeta potential of the non-conductive inorganic particles 102 is 50 mV or more. For this reason, the non-conductive inorganic particles 102 coated with the hydrophobizing agent are difficult to drop off. On the other hand, when a commonly used alkaline seeder is used, the pH of the catalyzed treatment liquid becomes 10-11. In this case, the absolute value of the difference between the measured value of the zeta potential of the resin particles 101 and the measured value of the zeta potential of the non-conductive inorganic particles 102 is about 30 to 50 mV. For this reason, in the pretreatment step, the non-conductive inorganic particles 102 are easily dropped from the resin particles 101.
　以上に説明した第１実施形態に係る導電粒子１００ａの作用効果について、上記特許文献１～３と比較しながら説明する。上記特許文献１、２に記載の方法に従って導電粒子を形成した場合、当該導電粒子における突起の数、大きさ及び形状を制御することは困難となっており、これらの導電粒子を用いた接着剤等の抵抗値が高くなる傾向にあった。このため、上記特許文献１、２に記載の導電粒子の導電性を高めようとした場合、長さが５００ｎｍを超える異常な大きさの突起（異常突起）が当該導電粒子の表面に形成される傾向にあった。このような異常突起（異常析出部）を有する導電粒子を用いた接着剤においては、絶縁信頼性が低下する傾向にあった。特に、特許文献２に記載の方法に従って導電粒子を形成する場合、導電粒子の電気抵抗値を下げるためには、基材となる微粒子の表面に充分な量の芯物質を付着させる必要がある。しかしながら、この芯物質の付着量を増やすと、芯物質自体が微粒子の表面にて凝集し、異常突起が形成されやすい傾向にある。 The effects of the conductive particles 100a according to the first embodiment described above will be described in comparison with the above-mentioned Patent Documents 1 to 3. When conductive particles are formed according to the methods described in Patent Documents 1 and 2, it is difficult to control the number, size, and shape of protrusions on the conductive particles, and an adhesive using these conductive particles Etc., the resistance value tended to increase. For this reason, when it is going to improve the electroconductivity of the electrically-conductive particle of the said patent document 1, 2, the protrusion (abnormal protrusion) of the abnormal magnitude | size exceeding 500 nm is formed in the surface of the said electroconductive particle. There was a trend. In an adhesive using conductive particles having such abnormal protrusions (abnormal precipitation portions), the insulation reliability tends to decrease. In particular, when conductive particles are formed according to the method described in Patent Document 2, it is necessary to attach a sufficient amount of core substance to the surface of fine particles serving as a substrate in order to reduce the electrical resistance value of the conductive particles. However, when the adhesion amount of the core substance is increased, the core substance itself tends to aggregate on the surface of the fine particles and abnormal projections tend to be formed.
　特許文献３に記載の方法では、樹脂粒子の表面に芯物質となる非導電性物質を化学結合により吸着させて複合粒子を形成する。この複合粒子に金属層を被覆するために、無電解ニッケルめっきを行うための前処理工程を、又は、無電解ニッケルめっき工程を行うと、非導電性物質が樹脂粒子から脱落してしまう。このため、複合粒子における突起の数、大きさ及び形状を制御することは困難となっており、これらの導電粒子を用いた接着剤などの抵抗値が高くなる傾向にあった。さらに、無電解ニッケルめっき工程時において、ニッケルが析出した非導電性物質が脱落すると、金属異物の発生源となる。この金属異物が複合粒子に再付着した場合、異常突起（異常析出部）が形成されることがある。さらには、上記金属異物そのものが接着剤に含有されることにより、絶縁信頼性低下の要因となることがあった。 In the method described in Patent Document 3, a non-conductive substance serving as a core substance is adsorbed on the surface of resin particles by chemical bonding to form composite particles. When the pretreatment process for performing electroless nickel plating or the electroless nickel plating process is performed in order to coat the composite particles with the metal layer, the non-conductive substance is dropped from the resin particles. For this reason, it is difficult to control the number, size, and shape of the protrusions in the composite particles, and the resistance value of an adhesive using these conductive particles tends to increase. Further, when the nonconductive material on which nickel is deposited falls during the electroless nickel plating step, it becomes a source of metal foreign matter. When the metal foreign matter reattaches to the composite particles, abnormal protrusions (abnormal precipitation portions) may be formed. Furthermore, when the metal foreign matter itself is contained in the adhesive, it may cause a decrease in insulation reliability.
　これらの特許文献１～３に対して、第１実施形態に係る製造方法によって形成された導電粒子１００ａによれば、樹脂粒子１０１はカチオン性ポリマーにより被覆され、非導電性無機粒子１０２は疎水化処理剤によって被覆される。非導電性無機粒子１０２の表面のゼータ電位は、疎水化によりマイナスにシフトする。これにより、樹脂粒子１０１と非導電性無機粒子１０２との間には静電気力が働き、樹脂粒子１０１の表面から非導電性無機粒子１０２が脱落しにくくなる。このため、樹脂粒子１０１の表面に配置される非導電性無機粒子１０２の数の制御が容易になると共に、複合粒子１０３に良好な突起１０９が形成される。したがって、導電粒子１００ａが配合された異方導電性接着剤を用いた接続構造体を高温高湿下に保存した場合であっても、導通信頼性が向上する。加えて、樹脂粒子１０１から脱落する非導電性無機粒子１０２の数が低減されるので、複合粒子１０３に異常に成長した突起が発生しにくくなる。このため、導電粒子１００ａが異方導電性接着剤に配合された場合等に導電粒子１００ａ同士が導通しにくくなり、導電粒子１００ａの絶縁信頼性も向上する。したがって、上記導電粒子を異方導電性接着剤に配合することによって、優れた導通信頼性及び絶縁信頼性を両立することができる。 In contrast to these patent documents 1 to 3, according to the conductive particles 100a formed by the manufacturing method according to the first embodiment, the resin particles 101 are coated with a cationic polymer, and the non-conductive inorganic particles 102 are hydrophobized. It is coated with a treatment agent. The zeta potential on the surface of the non-conductive inorganic particles 102 is shifted to minus due to the hydrophobicity. As a result, an electrostatic force acts between the resin particles 101 and the non-conductive inorganic particles 102, and the non-conductive inorganic particles 102 are less likely to drop off from the surface of the resin particles 101. For this reason, it becomes easy to control the number of the non-conductive inorganic particles 102 arranged on the surface of the resin particles 101, and good protrusions 109 are formed on the composite particles 103. Therefore, even when the connection structure using the anisotropic conductive adhesive containing the conductive particles 100a is stored under high temperature and high humidity, the conduction reliability is improved. In addition, since the number of non-conductive inorganic particles 102 that fall off from the resin particles 101 is reduced, abnormally grown protrusions are hardly generated on the composite particles 103. For this reason, when the electroconductive particle 100a is mix | blended with an anisotropic conductive adhesive etc., it becomes difficult for the electroconductive particles 100a to conduct | electrically_connect, and the insulation reliability of the electroconductive particle 100a improves. Therefore, excellent conduction reliability and insulation reliability can be achieved by blending the conductive particles with the anisotropic conductive adhesive.
　導電粒子１００ａにおいては、非導電性無機粒子１０２が樹脂粒子１０１から脱落しにくくなるので、異常析出部の発生を抑え、導電粒子を作製する際に金属異物の発生を低減できる。 In the conductive particles 100a, the non-conductive inorganic particles 102 are less likely to drop off from the resin particles 101, so that the occurrence of abnormal precipitation can be suppressed and the generation of metallic foreign matters can be reduced when producing conductive particles.
　疎水化処理剤は、シラザン系疎水化処理剤、シロキサン系疎水化処理剤、シラン系疎水化処理剤、及びチタネート系疎水化処理剤からなる群より選ばれる。 The hydrophobizing agent is selected from the group consisting of a silazane hydrophobizing agent, a siloxane hydrophobizing agent, a silane hydrophobizing agent, and a titanate hydrophobizing agent.
　疎水化処理剤は、ヘキサメチレンジシラザン、ポリジメチルシロキサン、及びＮ，Ｎ－ジメチルアミノトリメチルシランからなる群より選ばれてもよい。 The hydrophobizing agent may be selected from the group consisting of hexamethylene disilazane, polydimethylsiloxane, and N, N-dimethylaminotrimethylsilane.
　メタノール滴定法による非導電性無機粒子１０２の疎水化度は、例えば、３０％以上である。この場合、非導電性無機粒子１０２と樹脂粒子１０１との間に十分な静電気力が働く。 The degree of hydrophobicity of the non-conductive inorganic particles 102 by the methanol titration method is, for example, 30% or more. In this case, a sufficient electrostatic force acts between the non-conductive inorganic particles 102 and the resin particles 101.
　樹脂粒子１０１と非導電性無機粒子１０２とのゼータ電位の差は、例えば、ｐＨ１以上ｐＨ１１以下において３０ｍＶ以上である。この場合、樹脂粒子１０１と非導電性無機粒子１０２とが静電気力により強固に接着する。したがって、導電粒子１００ａにおける第１層１０４を形成するための前処理工程、第１層１０４の形成工程等の際に、樹脂粒子１０１から非導電性無機粒子１０２が脱落することを好適に抑制できる。 The difference in zeta potential between the resin particles 101 and the non-conductive inorganic particles 102 is, for example, 30 mV or more at pH 1 or more and pH 11 or less. In this case, the resin particles 101 and the non-conductive inorganic particles 102 are firmly bonded by electrostatic force. Accordingly, it is possible to suitably suppress the non-conductive inorganic particles 102 from dropping from the resin particles 101 during the pretreatment step for forming the first layer 104 in the conductive particles 100a, the formation step of the first layer 104, and the like. .
　カチオン性ポリマーは、ポリアミン、ポリイミン、ポリアミド、ポリジアリルジメチルアンモニウムクロリド、ポリビニルアミン、ポリビニルピリジン、ポリビニルイミダゾール及びポリビニルピロリドンからなる群より選ばれる。 The cationic polymer is selected from the group consisting of polyamine, polyimine, polyamide, polydiallyldimethylammonium chloride, polyvinylamine, polyvinylpyridine, polyvinylimidazole and polyvinylpyrrolidone.
　カチオン性ポリマーは、ポリエチレンイミンであってもよい。この場合、カチオン性ポリマーの電荷密度が高くなるので、非導電性無機粒子１０２の脱落を良好に抑制できる。 The cationic polymer may be polyethyleneimine. In this case, since the charge density of the cationic polymer is increased, it is possible to favorably suppress the non-conductive inorganic particles 102 from dropping off.
　非導電性無機粒子１０２の平均粒径は、例えば、２５ｎｍ以上１２０ｎｍ以下である。この場合、導電粒子１００ａは緻密な突起１０９を多数有することができると共に、非導電性無機粒子１０２が樹脂粒子１０１から脱落しにくくなる。 The average particle diameter of the non-conductive inorganic particles 102 is, for example, 25 nm or more and 120 nm or less. In this case, the conductive particles 100 a can have a large number of dense protrusions 109, and the nonconductive inorganic particles 102 are less likely to drop off from the resin particles 101.
　樹脂粒子の平均粒径は、例えば、１μｍ以上１０μｍ以下である。例えば、導電粒子１００ａを含む異方導電性接着剤を用いて接続構造体を作製した際に、当該接続構造体の電極の形状（高さ）のばらつきによって、当該異方導電性接着剤の導電性等が変化しにくくなる。 The average particle diameter of the resin particles is, for example, 1 μm or more and 10 μm or less. For example, when a connection structure is manufactured using an anisotropic conductive adhesive including the conductive particles 100a, the conductivity of the anisotropic conductive adhesive depends on variations in the shape (height) of the electrodes of the connection structure. Sex and the like are less likely to change.
　非導電性無機粒子１０２は、シリカ、ジルコニア、アルミナ、及びダイヤモンドからなる群より選ばれる。 Non-conductive inorganic particles 102 are selected from the group consisting of silica, zirconia, alumina, and diamond.
　金属層は、ニッケルを含有する第１層１０４を有する。加えて、当該第１層１０４は、無電解めっきにより複合粒子１０３を被覆する層である。この場合、導電粒子１００ａの硬度を高めることができる。これにより、当該導電粒子１００ａが圧縮された場合であっても、非導電性無機粒子１０２上に形成されて突起部分となった第１層１０４は、押し潰されにくくなる。したがって、導電粒子１００ａは、低い導通抵抗を得ることができる。 The metal layer has a first layer 104 containing nickel. In addition, the first layer 104 is a layer that covers the composite particles 103 by electroless plating. In this case, the hardness of the conductive particles 100a can be increased. Accordingly, even when the conductive particles 100a are compressed, the first layer 104 formed on the non-conductive inorganic particles 102 and serving as a protruding portion is not easily crushed. Therefore, the conductive particles 100a can obtain a low conduction resistance.
　金属層の第１層１０４は、複数の導電層を有してもよい。これらの導電層における厚さ、組成、形状の少なくとも一つが互いに異なってもよい。例えば、第１層１０４に置いて主成分となる金属の含有量は、第１層１０４の厚さ方向において表面に近づくにつれて高くなってもよい。このような複数の導電層を有する第１層１０４を形成するために、複数のめっき液を用いてもよい。例えば、析出する金属濃度が異なるめっき液を用いることによって、容易に複数の導電層を有する第１層１０４を形成できる。 The first layer 104 of the metal layer may have a plurality of conductive layers. At least one of the thickness, composition, and shape of these conductive layers may be different from each other. For example, the content of the metal that is the main component in the first layer 104 may increase as it approaches the surface in the thickness direction of the first layer 104. In order to form the first layer 104 having such a plurality of conductive layers, a plurality of plating solutions may be used. For example, the first layer 104 having a plurality of conductive layers can be easily formed by using plating solutions having different metal concentrations.
　第１層１０４は、例えば、第１めっき液の投入の後に、又は、第１めっき液の投入の終了前に当該第１めっき液よりも析出する金属濃度が異なる（高い）第２めっき液を投入し始めることによって形成されてもよい。この場合、厚さ方向における金属濃度が表面に向かって徐々に変化する（高くなる）第１層１０４を形成できる。また、異なる組成の複数の導電層を個別に形成する工程が不要になるので、短時間で第１層１０４を形成できる。 For example, the first layer 104 may be formed of a second plating solution having a different (higher) metal concentration than the first plating solution after the first plating solution is added or before the first plating solution is finished. It may be formed by starting to throw. In this case, the first layer 104 in which the metal concentration in the thickness direction gradually changes (increases) toward the surface can be formed. In addition, since the step of individually forming a plurality of conductive layers having different compositions is not necessary, the first layer 104 can be formed in a short time.
（第２実施形態）
　以下では、第２実施形態に係る導電粒子について説明する。第２実施形態の説明において第１実施形態と重複する記載は省略し、第１実施形態と異なる部分を記載する。つまり、技術的に可能な範囲において、第２実施形態に第１実施形態の記載を適宜用いてもよい。 (Second Embodiment)
Below, the electroconductive particle which concerns on 2nd Embodiment is demonstrated. In the description of the second embodiment, descriptions overlapping with the first embodiment are omitted, and only the parts different from the first embodiment are described. In other words, the description of the first embodiment may be used as appropriate for the second embodiment within the technically possible range.
　図３は、第２実施形態に係る導電粒子を示す模式断面図である。図３に示す導電粒子１００ｂは、第１層１０４上に設けられる第２層１０５を有する点以外は、図１に示される導電粒子１００ａと同様の構成を有している。第２層１０５は、金属層でもよいし、合金層でもよい。 FIG. 3 is a schematic cross-sectional view showing conductive particles according to the second embodiment. 3 has the same configuration as the conductive particle 100a shown in FIG. 1 except that the conductive particle 100b shown in FIG. 3 has a second layer 105 provided on the first layer 104. The second layer 105 may be a metal layer or an alloy layer.
＜第２層＞
　第２層１０５は、第１層１０４を被覆して設けられる導電層である。第２層１０５の厚さは、例えば、５ｎｍ～１００ｎｍである。第２層１０５の厚さは、５ｎｍ以上でもよく、１０ｎｍ以上でもよい。第２層１０５の厚さは、３０ｎｍ以下でもよい。第２層１０５の厚さが上記範囲内である場合、第２層１０５を形成する場合に当該第２層１０５の厚さを均一にできる、これにより、第１層１０４に含有される元素（例えば、ニッケル）が、第２層１０５とは反対側の表面へ拡散することを良好に防止できる。 <Second layer>
The second layer 105 is a conductive layer provided so as to cover the first layer 104. The thickness of the second layer 105 is, for example, 5 nm to 100 nm. The thickness of the second layer 105 may be 5 nm or more, or 10 nm or more. The thickness of the second layer 105 may be 30 nm or less. When the thickness of the second layer 105 is within the above range, the thickness of the second layer 105 can be made uniform when the second layer 105 is formed. For example, nickel) can be satisfactorily prevented from diffusing to the surface opposite to the second layer 105.
　第２層１０５の厚さは、ＴＥＭによって撮影された写真を用いて算出される。具体例として、まず、導電粒子１００ｂの中心付近を通るようにウルトラミクロトーム法で導電粒子１００ｂの断面を切り出す。次に、切り出した断面を、ＴＥＭを用いて２５万倍の倍率で観察して画像を得る。次に、得られた画像から見積もられる第２層１０５（図４）の断面積から、第２層１０５の厚さを算出できる。このとき、第２層１０５、第１層１０４、樹脂粒子１０１及び非導電性無機粒子１０２を区別しづらい場合には、ＴＥＭに付属するＥＤＸによる成分分析による成分分析を行う。これにより、第２層１０５、第１層１０４、樹脂粒子１０１及び非導電性無機粒子１０２を明確に区別し、第２層１０５のみの厚さを算出する。第２層１０５の厚さは、導電粒子１０個における厚さの平均値とする。 The thickness of the second layer 105 is calculated using a photograph taken by a TEM. As a specific example, first, a cross section of the conductive particle 100b is cut out by an ultramicrotome method so as to pass near the center of the conductive particle 100b. Next, the cut section is observed at a magnification of 250,000 times using a TEM to obtain an image. Next, the thickness of the second layer 105 can be calculated from the cross-sectional area of the second layer 105 (FIG. 4) estimated from the obtained image. At this time, when it is difficult to distinguish the second layer 105, the first layer 104, the resin particles 101, and the non-conductive inorganic particles 102, component analysis is performed by component analysis using EDX attached to the TEM. Thereby, the second layer 105, the first layer 104, the resin particles 101, and the non-conductive inorganic particles 102 are clearly distinguished, and the thickness of only the second layer 105 is calculated. The thickness of the second layer 105 is an average value of the thickness of 10 conductive particles.
　第２層１０５は、貴金属及びコバルトからなる群より選ばれる少なくとも一種を含有する。貴金属は、パラジウム、ロジウム、イリジウム、ルテニウム、白金、銀、又は金である。第２層１０５が金を含有する場合、導電粒子１００ｂの表面における導通抵抗を下げ、導電粒子１００ｂの導電特性を向上できる。この場合、第２層１０５は、ニッケルを含有する第１層１０４の酸化防止層として機能する。そのため、第２層１０５は、第１層１０４上に形成される。金を含有する場合の第２層１０５の厚さは、３０ｎｍ以下でもよい。この場合、導電粒子１００ｂの表面における導通抵抗の低減効果と製造コストとのバランスに優れる。しかしながら、金を含有する場合の第２層１０５の厚さは、３０ｎｍを超えていてもよい。 The second layer 105 contains at least one selected from the group consisting of noble metals and cobalt. The noble metal is palladium, rhodium, iridium, ruthenium, platinum, silver, or gold. When the 2nd layer 105 contains gold | metal | money, the conduction | electrical_connection resistance in the surface of the electroconductive particle 100b can be lowered | hung and the electroconductive characteristic of the electroconductive particle 100b can be improved. In this case, the second layer 105 functions as an antioxidant layer for the first layer 104 containing nickel. Therefore, the second layer 105 is formed on the first layer 104. The thickness of the second layer 105 in the case of containing gold may be 30 nm or less. In this case, the balance between the reduction effect of the conduction resistance on the surface of the conductive particle 100b and the manufacturing cost is excellent. However, the thickness of the second layer 105 in the case of containing gold may exceed 30 nm.
　第２層１０５は、パラジウム、ロジウム、イリジウム、ルテニウム及び白金からなる群より選ばれる少なくとも一種から構成されることが好ましい。この場合、導電粒子１００ｂの表面の酸化を抑制し、且つ導電粒子１００ｂの絶縁信頼性を向上できる。第２層１０５は、パラジウム、ロジウム、イリジウム及びルテニウムからなる群より選ばれる少なくとも一種から構成されることがより好ましい。この場合、導電粒子１００ｂを圧縮した場合であっても、非導電性無機粒子１０２上に形成される突起１０９になる第１層１０４が押しつぶされることが抑制され、圧縮された導電粒子１００ｂの抵抗増加が抑制される。第２層１０５は、例えば、第１実施形態の第４工程にて第１層１０４を形成した後、無電解めっきにて、当該第１層１０４によって覆われた複合粒子１０３上に形成される。 The second layer 105 is preferably composed of at least one selected from the group consisting of palladium, rhodium, iridium, ruthenium and platinum. In this case, the oxidation of the surface of the conductive particle 100b can be suppressed, and the insulation reliability of the conductive particle 100b can be improved. The second layer 105 is more preferably composed of at least one selected from the group consisting of palladium, rhodium, iridium, and ruthenium. In this case, even when the conductive particles 100b are compressed, the first layer 104 that becomes the protrusions 109 formed on the non-conductive inorganic particles 102 is suppressed from being crushed, and the resistance of the compressed conductive particles 100b is reduced. Increase is suppressed. The second layer 105 is formed on the composite particles 103 covered with the first layer 104 by, for example, electroless plating after forming the first layer 104 in the fourth step of the first embodiment. .
＜パラジウム＞
　第２層１０５がパラジウムを含有する場合、当該第２層１０５は、例えば、無電解パラジウムめっきによって形成することできる。無電解パラジウムめっきは、還元剤を用いない置換型、及び、還元剤を用いる還元型のいずれを用いてもよい。このような無電解パラジウムめっき液としては、置換型ではＭＣＡ（株式会社ワールドメタル製、商品名）等が挙げられる。還元型ではＡＰＰ（石原ケミカル株式会社製、商品名）等が挙げられる。置換型と還元型とを比較した場合、生じるボイドが少なく、被覆面積を確保し易い観点から、還元型が好ましい。 <Palladium>
When the second layer 105 contains palladium, the second layer 105 can be formed by, for example, electroless palladium plating. Electroless palladium plating may use either a substitution type that does not use a reducing agent or a reduction type that uses a reducing agent. As such an electroless palladium plating solution, MCA (trade name, manufactured by World Metal Co., Ltd.) and the like can be cited as a replacement type. Examples of the reduction type include APP (trade name, manufactured by Ishihara Chemical Co., Ltd.) and the like. When the substitution type and the reduction type are compared, the reduced type is preferable from the viewpoint of generating less voids and ensuring the covering area.
　第２層１０５がパラジウムを含有する場合、第２層１０５におけるパラジウムの含有量の下限は、第２層１０５の全量を基準として、９０質量％以上でもよく、９３質量％以上でもよく、９４質量％以上でもよい。第２層１０５におけるパラジウムの含有量の上限は、第２層１０５の全量を基準として、９９質量％以下でもよく、９８質量％以下でもよい。第２層１０５におけるパラジウムの含有量が上記範囲内である場合、第２層１０５の硬度が高くなる。このため、導電粒子１００ｂを圧縮した場合であっても突起１０９が押しつぶされることが抑制される。 When the second layer 105 contains palladium, the lower limit of the palladium content in the second layer 105 may be 90% by mass or more, 93% by mass or more, and 94% by mass based on the total amount of the second layer 105. % Or more. The upper limit of the palladium content in the second layer 105 may be 99% by mass or less or 98% by mass or less based on the total amount of the second layer 105. When the content of palladium in the second layer 105 is within the above range, the hardness of the second layer 105 is increased. For this reason, even if it is a case where the electroconductive particle 100b is compressed, it is suppressed that the protrusion 109 is crushed.
　第２層１０５におけるパラジウムの含有量を調整するため（例えば、９３～９９質量％に調整するため）に、無電解パラジウムめっき液に用いられる還元剤としては、特に制限はないが、次亜リン酸、亜リン酸、これらのアルカリ塩等のリン含有化合物；ホウ素含有化合物などを用いることができる。その場合は、得られる第２層１０５がパラジウム－リン合金又はパラジウム－ホウ素合金を含む。このため、第２層１０５におけるパラジウム含有量が所望の範囲となるように、還元剤の濃度、ｐＨ、めっき液の温度等を調整することが好ましい。 In order to adjust the content of palladium in the second layer 105 (for example, to adjust to 93 to 99% by mass), the reducing agent used in the electroless palladium plating solution is not particularly limited. Phosphorus-containing compounds such as acids, phosphorous acid, and alkali salts thereof; boron-containing compounds and the like can be used. In that case, the resulting second layer 105 includes a palladium-phosphorus alloy or a palladium-boron alloy. For this reason, it is preferable to adjust the concentration of the reducing agent, the pH, the temperature of the plating solution, and the like so that the palladium content in the second layer 105 falls within a desired range.
＜ロジウム＞
　第２層１０５がロジウムを含有する場合、当該第２層１０５は、例えば、無電解ロジウムめっきによって形成することできる。無電解ロジウムめっき液に用いるロジウムの供給源としては、例えば、水酸化アンミンロジウム、硝酸アンミンロジウム、酢酸アンミンロジウム、硫酸アンミンロジウム、亜硫酸アンミンロジウム、アンミンロジウム臭化物、及び、アンミンロジウム化合物が挙げられる。 <Rhodium>
When the second layer 105 contains rhodium, the second layer 105 can be formed by electroless rhodium plating, for example. Examples of the supply source of rhodium used in the electroless rhodium plating solution include ammine rhodium hydroxide, ammine rhodium nitrate, ammine rhodium acetate, ammine rhodium sulfate, ammine rhodium sulfite, ammine rhodium bromide, and an ammine rhodium compound.
　無電解ロジウムめっき液に用いる還元剤としては、例えば、ヒドラジン、次亜リン酸ナトリウム、ホウ酸ジメチルアミン、ホウ酸ジエチルアミン及び水素化硼素ナトリウムが挙げられる。還元剤としては、ヒドラジンが好ましい。無電解ロジウムめっき液中に、安定剤又は錯化剤（水酸化アンモニウム、ヒドロキシルアミン塩、二塩化ヒドラジン等）を添加してもよい。 Examples of the reducing agent used in the electroless rhodium plating solution include hydrazine, sodium hypophosphite, dimethylamine borate, diethylamine borate, and sodium borohydride. As the reducing agent, hydrazine is preferable. A stabilizer or complexing agent (ammonium hydroxide, hydroxylamine salt, hydrazine dichloride, etc.) may be added to the electroless rhodium plating solution.
　無電解ロジウムめっき液の温度（浴温）は、充分なめっき速度を得る観点から、４０℃以上でもよく、５０℃以上でもよい。めっき液の温度は、無電解ロジウムめっき液を安定に保持する観点から、９０℃以下でもよく、８０℃以下でもよい。 The temperature (bath temperature) of the electroless rhodium plating solution may be 40 ° C. or higher, or 50 ° C. or higher from the viewpoint of obtaining a sufficient plating rate. The temperature of the plating solution may be 90 ° C. or lower or 80 ° C. or lower from the viewpoint of stably holding the electroless rhodium plating solution.
＜イリジウム＞
　第２層１０５がイリジウムを含有する場合、当該第２層１０５は、例えば、無電解イリジウムめっきによって形成することできる。無電解イリジウムめっき液に用いるイリジウムの供給源としては、例えば、三塩化イリジウム、四塩化イリジウム、三臭化イリジウム、四臭化イリジウム、六塩化イリジウム三カリウム、六塩化イリジウム二カリウム、六塩化イリジウム三ナトリウム、六塩化イリジウム二ナトリウム、六臭化イリジウム三カリウム、六臭化イリジウム二カリウム、六ヨウ化イリジウム三カリウム、トリス硫酸二イリジウム、及び、ビス硫酸イリジウムが挙げられる。 <Iridium>
When the second layer 105 contains iridium, the second layer 105 can be formed by, for example, electroless iridium plating. Examples of the source of iridium used in the electroless iridium plating solution include iridium trichloride, iridium tetrachloride, iridium tribromide, iridium tetrabromide, iridium hexachloride, tripotassium hexachloride, iridium hexachloride, iridium hexachloride Examples include sodium, disodium iridium hexachloride, tripotassium iridium hexabromide, dipotassium iridium hexabromide, tripotassium iridium hexaiodide, diiridium trissulfate, and iridium bissulfate.
　無電解イリジウムめっき液に用いる還元剤としては、例えば、ヒドラジン、次亜リン酸ナトリウム、ホウ酸ジメチルアミン、ホウ酸ジエチルアミン、及び、水素化硼素ナトリウムが挙げられる。還元剤としては、ヒドラジンが好ましい。無電解イリジウムめっき液中に、安定剤又は錯化剤を添加してもよい。 Examples of the reducing agent used in the electroless iridium plating solution include hydrazine, sodium hypophosphite, dimethylamine borate, diethylamine borate, and sodium borohydride. As the reducing agent, hydrazine is preferable. A stabilizer or complexing agent may be added to the electroless iridium plating solution.
　安定剤又は錯化剤としては、モノカルボン酸、ジカルボン酸及びこれらの塩からなる群より選択される少なくとも一種を添加してもよい。モノカルボン酸の具体例としては、ギ酸、酢酸、プロピオン酸、酪酸、乳酸等が挙げられる。ジカルボン酸の具体例としては、シュウ酸、マロン酸、コハク酸、グルタル酸、アジピン酸、フマル酸、マレイン酸、リンゴ酸等が挙げられる。上記塩としては、例えば、上記カルボン酸に対してナトリウム、カリウム、リチウム等が対イオンとして結合している化合物が挙げられる。安定剤又は錯化剤は、一種を単独で又は二種以上を組み合わせて用いることができる。 As the stabilizer or complexing agent, at least one selected from the group consisting of monocarboxylic acids, dicarboxylic acids and salts thereof may be added. Specific examples of the monocarboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, lactic acid and the like. Specific examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, malic acid and the like. Examples of the salt include compounds in which sodium, potassium, lithium or the like is bound as a counter ion to the carboxylic acid. A stabilizer or a complexing agent can be used individually by 1 type or in combination of 2 or more types.
　無電解イリジウムめっき液のｐＨは、めっき対象物の腐食を抑制すると共に、充分なめっき速度を得る観点から、１以上でもよく、２以上でもよい。無電解イリジウムめっき液のｐＨは、めっき反応の阻害が抑制され易い観点から、６以下でもよく、５以下でもよい。 The pH of the electroless iridium plating solution may be 1 or more, or 2 or more from the viewpoint of suppressing corrosion of the plating object and obtaining a sufficient plating rate. The pH of the electroless iridium plating solution may be 6 or less or 5 or less from the viewpoint that inhibition of the plating reaction is easily suppressed.
　無電解イリジウムめっき液の温度（浴温）は、充分なめっき速度を得る観点から、４０℃以上でもよく、５０℃以上でもよい。無電解イリジウムめっき液の温度（浴温）は、無電解イリジウムめっき液を安定に保持する観点から、９０℃以下でもよく、８０℃以下でもよい。 The temperature (bath temperature) of the electroless iridium plating solution may be 40 ° C. or higher, or 50 ° C. or higher from the viewpoint of obtaining a sufficient plating rate. The temperature (bath temperature) of the electroless iridium plating solution may be 90 ° C. or less or 80 ° C. or less from the viewpoint of stably holding the electroless iridium plating solution.
＜ルテニウム＞
　第２層１０５がルテニウムを含有する場合、当該第２層１０５は、例えば、無電解ルテニウムめっきによって形成することできる。無電解ルテニウムめっき液としては、例えば、市販のめっき液を用いることが可能であり、無電解ルテニウムＲｕ（奥野製薬工業株式会社製、商品名）を用いることができる。 <Ruthenium>
When the second layer 105 contains ruthenium, the second layer 105 can be formed by electroless ruthenium plating, for example. As the electroless ruthenium plating solution, for example, a commercially available plating solution can be used, and electroless ruthenium Ru (trade name, manufactured by Okuno Pharmaceutical Co., Ltd.) can be used.
＜白金＞
　第２層１０５が白金を含有する場合、当該第２層１０５は、例えば、無電解白金めっきによって形成することできる。無電解白金めっき液に用いる白金の供給源としては、例えば、Ｐｔ（ＮＨ３）４（ＮＯ３）２、Ｐｔ（ＮＨ３）４（ＯＨ）２、ＰｔＣｌ２（ＮＨ３）２、Ｐｔ（ＮＨ３）２（ＯＨ）２、（ＮＨ４）２ＰｔＣｌ６、（ＮＨ４）２ＰｔＣｌ４、Ｐｔ（ＮＨ３）２Ｃｌ４、Ｈ２ＰｔＣｌ６、及び、ＰｔＣｌ２が挙げられる。 <Platinum>
When the second layer 105 contains platinum, the second layer 105 can be formed by, for example, electroless platinum plating. As a supply source of platinum used for the electroless platinum plating solution, for example, Pt (NH 3 ) 4 (NO 3 ) 2 , Pt (NH 3 ) 4 (OH) 2 , PtCl 2 (NH 3 ) 2 , Pt (NH) 3 ) 2 (OH) 2 , (NH 4 ) 2 PtCl 6 , (NH 4 ) 2 PtCl 4 , Pt (NH 3 ) 2 Cl 4 , H 2 PtCl 6 , and PtCl 2 .
　無電解白金めっき液に用いる還元剤としては、例えば、ヒドラジン、次亜リン酸ナトリウム、ホウ酸ジメチルアミン、ホウ酸ジエチルアミン、及び、水素化硼素ナトリウムが挙げられる。還元剤としては、ヒドラジンが好ましい。無電解白金めっき液中に、安定剤又は錯化剤（塩化ヒドロキシルアミン、二塩化ヒドラジン、水酸化アンモニウム、ＥＤＴＡ等）を添加してもよい。 Examples of the reducing agent used in the electroless platinum plating solution include hydrazine, sodium hypophosphite, dimethylamine borate, diethylamine borate, and sodium borohydride. As the reducing agent, hydrazine is preferable. A stabilizer or complexing agent (hydroxylamine chloride, hydrazine dichloride, ammonium hydroxide, EDTA, etc.) may be added to the electroless platinum plating solution.
　無電解白金めっき液の温度（浴温）は、充分なめっき速度を得る観点から、４０℃以上でもよく、５０℃以上でもよい。無電解白金めっき液の温度（浴温）は、無電解白金めっき液を安定に保持する観点から、９０℃以下でもよく、８０℃以下でもよい。 The temperature (bath temperature) of the electroless platinum plating solution may be 40 ° C. or higher, or 50 ° C. or higher from the viewpoint of obtaining a sufficient plating rate. The temperature (bath temperature) of the electroless platinum plating solution may be 90 ° C. or less or 80 ° C. or less from the viewpoint of stably holding the electroless platinum plating solution.
　無電解白金めっき液を用いて白金めっきを行う際、無電解白金めっき液のｐＨは、８～１２であればよい。ｐＨが８以上であると、充分に白金が析出し易い。ｐＨが１２以下であると、良好な作業環境を容易に確保できる。 When performing platinum plating using an electroless platinum plating solution, the pH of the electroless platinum plating solution may be 8-12. When the pH is 8 or more, platinum is sufficiently easily precipitated. When the pH is 12 or less, a good working environment can be easily secured.
＜銀＞
　第２層１０５が銀を含有する場合、当該第２層１０５は、例えば、無電解銀めっきによって形成することできる。無電解銀めっき液に用いる銀の供給源としては、めっき液に可溶であるものであれば特に限定されない。例えば、硝酸銀、酸化銀、硫酸銀、塩化銀、亜硫酸銀、炭酸銀、酢酸銀、乳酸銀、スルホコハク酸銀、スルホン酸銀、スルファミン酸銀、及びシュウ酸銀が用いられる。水溶性銀化合物は、一種を単独で又は二種以上を組み合わせて用いることができる。 <Silver>
When the second layer 105 contains silver, the second layer 105 can be formed by, for example, electroless silver plating. The silver supply source used in the electroless silver plating solution is not particularly limited as long as it is soluble in the plating solution. For example, silver nitrate, silver oxide, silver sulfate, silver chloride, silver sulfite, silver carbonate, silver acetate, silver lactate, silver sulfosuccinate, silver sulfonate, silver sulfamate, and silver oxalate are used. A water-soluble silver compound can be used individually by 1 type or in combination of 2 or more types.
　無電解銀めっき液に用いる還元剤としては、無電解銀めっき液中の水溶性銀化合物を金属銀に還元する能力を有するものであって水溶性の化合物であれば特に限定されない。例えば、ヒドラジン誘導体、ホルムアルデヒド化合物、ヒドロキシルアミン類、糖類、ロッセル塩、水素化ホウ素化合物、次亜リン酸塩、ＤＭＡＢ、及び、アスコルビン酸を用いることができる。還元剤は、一種を単独で又は二種以上を組み合わせて用いることができる。 The reducing agent used in the electroless silver plating solution is not particularly limited as long as it has the ability to reduce the water-soluble silver compound in the electroless silver plating solution to metallic silver and is a water-soluble compound. For example, hydrazine derivatives, formaldehyde compounds, hydroxylamines, saccharides, Rossell salts, borohydride compounds, hypophosphites, DMAB, and ascorbic acid can be used. A reducing agent can be used individually by 1 type or in combination of 2 or more types.
　無電解銀めっき液中に、安定剤又は錯化剤を添加してもよい。安定剤又は錯化剤としては、例えば、亜硫酸塩、コハク酸イミド、ヒダントイン誘導体、エチレンジアミン、及びエチレンジアミン四酢酸（ＥＤＴＡ）を用いることができる。安定剤又は錯化剤は、一種を単独で又は二種以上を組み合わせて用いることができる。 A stabilizer or complexing agent may be added to the electroless silver plating solution. As the stabilizer or complexing agent, for example, sulfite, succinimide, hydantoin derivative, ethylenediamine, and ethylenediaminetetraacetic acid (EDTA) can be used. A stabilizer or a complexing agent can be used individually by 1 type or in combination of 2 or more types.
　無電解銀めっき液には、上述の成分以外に、公知の界面活性剤、ｐＨ調整剤、緩衝剤、平滑剤、応力緩和剤等の添加剤を添加してもよい。 In addition to the above-mentioned components, additives such as known surfactants, pH adjusters, buffers, smoothing agents, stress relieving agents may be added to the electroless silver plating solution.
　無電解銀めっき液は、液温として０～８０℃の範囲であればよい。無電解銀めっき液の温度が０℃以上であると、銀の析出速度が充分に速く、所定の銀析出量を得るための時間を短縮することができる。無電解銀めっき液の温度が８０℃以下であると、自己分解反応による還元剤の損失、及び、無電解銀めっき液の安定性の低下を抑制できる。１０～６０℃程度にすると、無電解銀めっき液の安定性をより一層良好にすることができる。 The electroless silver plating solution may be in the range of 0 to 80 ° C. as the solution temperature. When the temperature of the electroless silver plating solution is 0 ° C. or higher, the silver deposition rate is sufficiently high, and the time for obtaining a predetermined silver deposition amount can be shortened. When the temperature of the electroless silver plating solution is 80 ° C. or lower, it is possible to suppress the loss of the reducing agent due to the self-decomposition reaction and the decrease in the stability of the electroless silver plating solution. When the temperature is about 10 to 60 ° C., the stability of the electroless silver plating solution can be further improved.
　無電解銀めっき液（例えば、還元型無電解銀めっき液）のｐＨは、例えば、１～１４である。めっき液のｐＨが６～１３程度であることによって、めっき液の安定性をより一層良好にすることができる。めっき液のｐＨ調整として、通常、ｐＨを下げる場合には、水溶性銀塩のアニオン部分と同種のアニオン部分を有する酸（例えば、水溶性銀塩として硫酸銀を用いる場合には硫酸、水溶性銀塩として硝酸銀を用いる場合には硝酸）が用いられる。無電解銀めっき液のｐＨを上げる場合には、アルカリ金属水酸化物、アンモニア等が用いられる。 The pH of the electroless silver plating solution (for example, reduced electroless silver plating solution) is, for example, 1 to 14. When the pH of the plating solution is about 6 to 13, the stability of the plating solution can be further improved. In order to adjust the pH of the plating solution, when lowering the pH, an acid having an anion portion of the same kind as that of the water-soluble silver salt (for example, sulfuric acid, water-soluble when silver sulfate is used as the water-soluble silver salt) Nitric acid is used when silver nitrate is used as the silver salt. In order to increase the pH of the electroless silver plating solution, alkali metal hydroxide, ammonia or the like is used.
＜金＞
　第２層１０５が金を含有する場合、当該第２層１０５は、例えば、無電解金めっきによって形成することできる。無電解金めっき液としては、置換型金めっき液（例えば、日立化成株式会社製、商品名「ＨＧＳ－１００」）、還元型金めっき液（例えば、日立化成株式会社製、商品名「ＨＧＳ－２０００」）等を用いることができる。置換型と還元型とを比較した場合、ボイドが少なく、被覆面積を確保し易い観点から、還元型を用いることが好ましい。 <Friday>
When the second layer 105 contains gold, the second layer 105 can be formed by, for example, electroless gold plating. Examples of the electroless gold plating solution include a displacement type gold plating solution (for example, product name “HGS-100” manufactured by Hitachi Chemical Co., Ltd.) and a reduction type gold plating solution (for example, product name “HGS- manufactured by Hitachi Chemical Co., Ltd.). 2000 ") or the like. When the substitution type and the reduction type are compared, it is preferable to use the reduction type from the viewpoint that there are few voids and the covering area is easily secured.
＜コバルト＞
　第２層１０５がコバルトを含有する場合、当該第２層１０５は、例えば、無電解コバルトめっきによって形成することできる。無電解コバルトめっき液に用いるコバルトの供給源としては、例えば、硫酸コバルト、塩化コバルト、硝酸コバルト、酢酸コバルト、及び、炭酸コバルトが挙げられる。 <Cobalt>
When the second layer 105 contains cobalt, the second layer 105 can be formed by, for example, electroless cobalt plating. Examples of the cobalt supply source used in the electroless cobalt plating solution include cobalt sulfate, cobalt chloride, cobalt nitrate, cobalt acetate, and cobalt carbonate.
　無電解コバルトめっき液に用いる還元剤としては、例えば、次亜リン酸ナトリウム、次亜リン酸アンモニウム、次亜リン酸ニッケル等の次亜リン酸塩、及び、次亜リン酸が用いられる。無電解コバルトめっき液中に、安定剤又は錯化剤（脂肪族カルボン酸等）を添加してもよい。安定剤又は錯化剤は、一種を単独で又は二種以上を組み合わせて用いることができる。 Examples of the reducing agent used in the electroless cobalt plating solution include hypophosphites such as sodium hypophosphite, ammonium hypophosphite, nickel hypophosphite, and hypophosphorous acid. A stabilizer or a complexing agent (such as an aliphatic carboxylic acid) may be added to the electroless cobalt plating solution. A stabilizer or a complexing agent can be used individually by 1 type or in combination of 2 or more types.
　無電解コバルトめっき液の温度（浴温）は、充分なめっき速度を得る観点から、４０℃以上でもよく、５０℃以上でもよい。無電解コバルトめっき液の温度（浴温）は、無電解コバルトめっき液を安定に保持する観点から、９０℃以下でもよく、８０℃以下でもよい。 The temperature (bath temperature) of the electroless cobalt plating solution may be 40 ° C. or higher or 50 ° C. or higher from the viewpoint of obtaining a sufficient plating rate. The temperature (bath temperature) of the electroless cobalt plating solution may be 90 ° C. or less or 80 ° C. or less from the viewpoint of stably holding the electroless cobalt plating solution.
　以上に説明した第２実施形態に係る導電粒子１００ｂにおいても、第１実施形態に係る導電粒子１００ａと同様に、樹脂粒子１０１の表面から非導電性無機粒子１０２が脱落しにくくなる。このため、樹脂粒子１０１の表面に配置される非導電性無機粒子１０２の数の制御が容易になると共に、複合粒子１０３に良好な突起１０９が形成される。したがって、導電粒子１００ｂが配合された異方導電性接着剤を用いた接続構造体を高温高湿下に保存した場合であっても、導通信頼性が向上する。加えて、樹脂粒子１０１から脱落する非導電性無機粒子１０２の数が低減されるので、複合粒子１０３に異常に成長した突起が発生しにくくなる。したがって、導電粒子１００ａが異方導電性接着剤に配合された場合等に導電粒子１００ｂ同士が導通しにくくなり、導電粒子１００ｂの絶縁信頼性も向上する。 Also in the conductive particles 100b according to the second embodiment described above, the non-conductive inorganic particles 102 are less likely to drop off from the surfaces of the resin particles 101, as with the conductive particles 100a according to the first embodiment. For this reason, it becomes easy to control the number of the non-conductive inorganic particles 102 arranged on the surface of the resin particles 101, and good protrusions 109 are formed on the composite particles 103. Therefore, even when the connection structure using the anisotropic conductive adhesive containing the conductive particles 100b is stored under high temperature and high humidity, the conduction reliability is improved. In addition, since the number of non-conductive inorganic particles 102 that fall off from the resin particles 101 is reduced, abnormally grown protrusions are hardly generated on the composite particles 103. Therefore, when the conductive particles 100a are blended in the anisotropic conductive adhesive, the conductive particles 100b are less likely to conduct with each other, and the insulation reliability of the conductive particles 100b is improved.
　第１実施形態においては、第１層１０４が導電粒子１００ａの最外層となる。この導電粒子１００ａが、例えば、異方導電性接着剤内に分散した際、第１層１０４内に含有されるニッケルが接着剤中に溶出してマイグレーションすることがある。このマイグレーションしたニッケルによって、異方導電性接着剤の絶縁信頼性が低下することがある。これに対して、第２実施形態の金属層は、第１層１０４上に設けられる第２層１０５を有し、第２層１０５は、貴金属及びコバルトからなる群より選ばれる金属を含有する。この場合、導電粒子１００ｂの最外層は第２層１０５になる。この第２層１０５は、第１層１０４からニッケルの溶出を防ぐ機能を有するので、当該ニッケルのマイグレーションの発生を抑制できる。加えて、当該第２層１０５は比較的酸化しにくいので、導電粒子１００ｂの導電性能が劣化しにくい。導電粒子１００ｂが第２層１０５を有することにより、突起１０９の数、大きさ及び形状を高度に制御することが可能になる。 In the first embodiment, the first layer 104 is the outermost layer of the conductive particles 100a. For example, when the conductive particles 100a are dispersed in the anisotropic conductive adhesive, nickel contained in the first layer 104 may be eluted into the adhesive and migrate. The migrated nickel may reduce the insulation reliability of the anisotropic conductive adhesive. On the other hand, the metal layer of the second embodiment has a second layer 105 provided on the first layer 104, and the second layer 105 contains a metal selected from the group consisting of noble metals and cobalt. In this case, the outermost layer of the conductive particles 100 b becomes the second layer 105. Since the second layer 105 has a function of preventing elution of nickel from the first layer 104, the occurrence of nickel migration can be suppressed. In addition, since the second layer 105 is relatively difficult to oxidize, the conductive performance of the conductive particles 100b is unlikely to deteriorate. When the conductive particles 100b include the second layer 105, the number, size, and shape of the protrusions 109 can be highly controlled.
（第３実施形態）
　以下では、第３実施形態に係る絶縁被覆導電粒子について説明する。第３実施形態の説明において第１実施形態及び第２実施形態と重複する記載は省略し、第１実施形態及び第２実施形態と異なる部分を記載する。つまり、技術的に可能な範囲において、第３実施形態に第１実施形態及び第２実施形態の記載を適宜用いてもよい。 (Third embodiment)
Hereinafter, the insulating coated conductive particles according to the third embodiment will be described. In the description of the third embodiment, the description overlapping with the first embodiment and the second embodiment is omitted, and only parts different from the first embodiment and the second embodiment are described. In other words, the descriptions of the first embodiment and the second embodiment may be appropriately used for the third embodiment within the technically possible range.
＜絶縁被覆導電粒子＞
　図５は、本実施形態に係る絶縁被覆導電粒子を示す模式断面図である。図５に示される絶縁被覆導電粒子２００は、第１実施形態に係る導電粒子１００ａと、第１層１０４の表面の少なくとも一部を被覆する絶縁性粒子（絶縁性被覆部）２１０と、を備える。 <Insulation coated conductive particles>
FIG. 5 is a schematic cross-sectional view showing the insulating coated conductive particles according to the present embodiment. 5 includes the conductive particles 100a according to the first embodiment and the insulating particles (insulating covering portion) 210 that covers at least a part of the surface of the first layer 104. The conductive particles 100a illustrated in FIG. .
　絶縁性粒子２１０の平均粒径は、絶縁性粒子２１０の正投影面において、絶縁性粒子２１０の面積と同一の面積を有する真円の直径から算出した平均粒径を意味する。絶縁性粒子２１０の平均粒径は、例えば、２０～５００ｎｍである。絶縁性粒子２１０の平均粒径が上記範囲内である場合、例えば、導電粒子１００ａに吸着された絶縁性粒子２１０が絶縁膜として有効に作用し易い。また、接続の加圧方向の導電性が良好になり易い。絶縁性粒子２１０の平均粒径は、例えば、ＢＥＴ法による比表面積換算法、又は、Ｘ線小角散乱法で測定してもよい。 The average particle diameter of the insulating particles 210 means an average particle diameter calculated from the diameter of a perfect circle having the same area as the area of the insulating particles 210 on the orthographic projection surface of the insulating particles 210. The average particle diameter of the insulating particles 210 is, for example, 20 to 500 nm. When the average particle diameter of the insulating particles 210 is within the above range, for example, the insulating particles 210 adsorbed on the conductive particles 100a are likely to effectively act as an insulating film. Also, the conductivity in the pressurizing direction of the connection tends to be good. The average particle diameter of the insulating particles 210 may be measured by, for example, a specific surface area conversion method by the BET method or an X-ray small angle scattering method.
　電気抵抗を下げ易く、且つ、電気抵抗の経時的な上昇を抑制し易い観点から、絶縁性粒子２１０の平均粒径は、導電粒子１００ａの平均粒径に対して、１／１０以下でもよく、１／１５以下でもよい。絶縁性粒子２１０の平均粒径は、更に良好な絶縁信頼性を得る観点から、導電粒子１００ａの平均粒径に対して、１／２０以上であってもよい。 From the viewpoint of easily reducing the electrical resistance and suppressing the increase in electrical resistance over time, the average particle size of the insulating particles 210 may be 1/10 or less with respect to the average particle size of the conductive particles 100a. It may be 1/15 or less. The average particle diameter of the insulating particles 210 may be 1/20 or more with respect to the average particle diameter of the conductive particles 100a from the viewpoint of obtaining better insulation reliability.
　導電粒子１００ａに対する絶縁性粒子２１０の被覆率が、例えば、２０～７０％となるように、絶縁性粒子２１０は導電粒子１００ａの表面を被覆する。絶縁性と導電性の効果を一層確実に得る観点から、被覆率は、２０～６０％でもよく、２５～６０％でもよく、２８～５５％でもよい。「被覆率」は、絶縁被覆導電粒子２００の正投影面において、絶縁被覆導電粒子２００の直径の１／２の直径を有する同心円内における絶縁性粒子２１０の表面積の割合を意味する。具体的には、絶縁性粒子２１０が形成された絶縁被覆導電粒子２００をＳＥＭにより３万倍で観察して得られる画像を解析し、絶縁被覆導電粒子２００の表面において絶縁性粒子２１０が占める割合を算出する。 The insulating particles 210 cover the surfaces of the conductive particles 100a so that the coverage of the insulating particles 210 with respect to the conductive particles 100a is, for example, 20 to 70%. From the viewpoint of more reliably obtaining the insulating and conductive effects, the coverage may be 20 to 60%, 25 to 60%, or 28 to 55%. “Coverage” means the ratio of the surface area of the insulating particles 210 in a concentric circle having a diameter ½ of the diameter of the insulating coated conductive particles 200 on the orthographic projection surface of the insulating coated conductive particles 200. Specifically, an image obtained by observing the insulating coated conductive particles 200 on which the insulating particles 210 are formed at 30,000 times by SEM is analyzed, and the ratio of the insulating particles 210 to the surface of the insulating coated conductive particles 200 Is calculated.
　導電粒子１００ａを被覆する絶縁性粒子２１０としては、有機高分子化合物微粒子、無機酸化物微粒子等が挙げられる。絶縁性粒子２１０として、無機酸化物微粒子を用いる場合には、絶縁信頼性を向上させやすく、有機高分子化合物微粒子を用いる場合には、導通抵抗を容易に下げることができる。 Examples of the insulating particles 210 covering the conductive particles 100a include organic polymer compound fine particles and inorganic oxide fine particles. When inorganic oxide fine particles are used as the insulating particles 210, the insulation reliability can be easily improved, and when organic polymer compound fine particles are used, the conduction resistance can be easily lowered.
　有機高分子化合物としては、熱軟化性を有する化合物であればよく、具体的には、ポリエチレン、エチレン－酢酸ビニル共重合体、エチレン－（メタ）アクリル酸共重合体、エチレン－（メタ）アクリル酸エステル共重合体、ポリエステル、ポリアミド、ポリウレタン、ポリスチレン、スチレン－ジビニルベンゼン共重合体、スチレン－イソブチレン共重合体、スチレン－ブタジエン共重合体、スチレン－（メタ）アクリル酸共重合体、エチレン－プロピレン共重合体、（メタ）アクリル酸エステル系ゴム、スチレン－エチレン－ブチレン共重合体、フェノキシ樹脂、固形エポキシ樹脂等が用いられる。有機高分子化合物は、一種を単独で又は二種以上を組み合わせて用いることができる。 The organic polymer compound may be any compound having heat softening properties, and specifically, polyethylene, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic. Acid ester copolymer, polyester, polyamide, polyurethane, polystyrene, styrene-divinylbenzene copolymer, styrene-isobutylene copolymer, styrene-butadiene copolymer, styrene- (meth) acrylic acid copolymer, ethylene-propylene Copolymers, (meth) acrylic ester rubbers, styrene-ethylene-butylene copolymers, phenoxy resins, solid epoxy resins and the like are used. An organic polymer compound can be used individually by 1 type or in combination of 2 or more types.
　無機酸化物としては、例えば、ケイ素、アルミニウム、ジルコニウム、チタン、ニオブ、亜鉛、錫、セリウム及びマグネシウムからなる群より選ばれる少なくとも一種の元素を含む酸化物が挙げられる。無機酸化物は、一種を単独で又は二種以上を組み合わせて用いることができる。無機酸化物の中でも、シリカが好ましい。シリカの中でも、水分散コロイダルシリカ（ＳｉＯ２）は、表面に水酸基を有するために導電粒子との結合性に優れ、粒径を揃え易く、安価であるため特に好適である。このような無機酸化物の微粒子の市販品としては、例えば、スノーテックス、スノーテックスＵＰ（日産化学工業株式会社製、商品名）、及び、クオートロンＰＬシリーズ（扶桑化学工業株式会社製、商品名）が挙げられる。 Examples of the inorganic oxide include oxides containing at least one element selected from the group consisting of silicon, aluminum, zirconium, titanium, niobium, zinc, tin, cerium, and magnesium. An inorganic oxide can be used individually by 1 type or in combination of 2 or more types. Of the inorganic oxides, silica is preferred. Among silicas, water-dispersed colloidal silica (SiO 2 ) is particularly suitable because it has a hydroxyl group on the surface, is excellent in binding properties with conductive particles, easily has a uniform particle size, and is inexpensive. Examples of such commercially available fine particles of inorganic oxide include Snowtex, Snowtex UP (trade name, manufactured by Nissan Chemical Industries, Ltd.), and Quatron PL series (trade name, manufactured by Fuso Chemical Industries, Ltd.). Is mentioned.
　無機酸化物微粒子が表面に水酸基を有する場合には、水酸基をシランカップリング剤等で、アミノ基、カルボキシル基、エポキシ基等に変性することができる。但し、無機酸化物微粒子の平均粒径が５００ｎｍ以下である場合、変性しにくい場合がある。その場合には、変性を行わずに導電粒子１００ａを被覆してもよい。 When the inorganic oxide fine particles have a hydroxyl group on the surface, the hydroxyl group can be modified to an amino group, a carboxyl group, an epoxy group or the like with a silane coupling agent or the like. However, when the average particle size of the inorganic oxide fine particles is 500 nm or less, it may be difficult to modify. In that case, the conductive particles 100a may be coated without modification.
　一般的に、無機酸化物微粒子の表面が水酸基を有することにより、シランカップリング剤等の表面処理剤の水酸基、カルボキシル基、アルコキシル基、アルコキシカルボニル基等と結合することができる。結合形態としては、例えば、脱水縮合による共有結合、水素結合、及び配位結合が挙げられる。 Generally, when the surface of the inorganic oxide fine particles has a hydroxyl group, it can be bonded to a hydroxyl group, a carboxyl group, an alkoxyl group, an alkoxycarbonyl group or the like of a surface treatment agent such as a silane coupling agent. Examples of the bonding form include a covalent bond by dehydration condensation, a hydrogen bond, and a coordination bond.
　導電粒子１００ａの外表面が金又はパラジウムからなる場合、これらに対して配位結合を形成するメルカプト基、スルフィド基、ジスルフィド基等を分子内に有する化合物を用いて無機酸化物微粒子の表面に水酸基、カルボキシル基、アルコキシル基、アルコキシカルボニル基等の官能基を形成するとよい。上記化合物としては、例えば、メルカプト酢酸、２－メルカプトエタノール、メルカプト酢酸メチル、メルカプトコハク酸、チオグリセリン、及び、システインが挙げられる。 When the outer surface of the conductive particle 100a is made of gold or palladium, a hydroxyl group is formed on the surface of the inorganic oxide fine particle using a compound having a mercapto group, sulfide group, disulfide group or the like that forms a coordinate bond with these particles in the molecule. A functional group such as a carboxyl group, an alkoxyl group, or an alkoxycarbonyl group may be formed. Examples of the compound include mercaptoacetic acid, 2-mercaptoethanol, methyl mercaptoacetate, mercaptosuccinic acid, thioglycerin, and cysteine.
　金、パラジウム等の貴金属、銅などはチオールと反応し易い。ニッケル等の卑金属はチオールと反応し難い。したがって、導電粒子１００ａの最外層が貴金属、銅等からなる場合は、導電粒子１００ａの最外層が卑金属からなる場合と比べてチオールと反応し易い。 Gold, palladium and other precious metals, copper, etc. are likely to react with thiols. Base metals such as nickel are difficult to react with thiols. Therefore, when the outermost layer of the conductive particles 100a is made of a noble metal, copper, or the like, it reacts more easily with thiol than when the outermost layer of the conductive particles 100a is made of a base metal.
　例えば、金表面に上記化合物を処理する方法としては、特に限定されないが、メタノール、エタノール等の有機溶媒中にメルカプト酢酸等の上記化合物を１０～１００ｍｍｏｌ／Ｌ程度分散し、その中に、最外層が金である導電粒子１００ａを分散させることができる。 For example, the method for treating the above compound on the gold surface is not particularly limited, but the above compound such as mercaptoacetic acid is dispersed in an organic solvent such as methanol and ethanol in an amount of about 10 to 100 mmol / L, and the outermost layer is contained therein. It is possible to disperse the conductive particles 100a in which is gold.
　次に、第１実施形態に係る導電粒子１００ａから第３実施形態に係る絶縁被覆導電粒子２００を製造する方法の一例を説明する。導電粒子１００ａの表面を絶縁性粒子２１０で被覆する方法としては、例えば、高分子電解質と絶縁性粒子とを交互に積層する方法が挙げられる。 Next, an example of a method for producing the insulating coated conductive particles 200 according to the third embodiment from the conductive particles 100a according to the first embodiment will be described. Examples of the method of coating the surface of the conductive particles 100a with the insulating particles 210 include a method of alternately laminating polymer electrolytes and insulating particles.
　まず、（１）導電粒子１００ａを高分子電解質溶液に分散し、当該導電粒子１００ａの表面に高分子電解質を吸着させた後、リンスする工程を行う。次に、（２）導電粒子１００ａを絶縁性粒子の分散溶液に分散し、当該導電粒子１００ａの表面に絶縁性粒子を吸着させた後、リンスする工程を行う。これらの工程を経て、高分子電解質と絶縁性粒子とが積層された絶縁性粒子２１０によって表面が被覆された絶縁被覆導電粒子２００を製造できる。（１）の工程及び（２）の工程は、（１）、（２）の順でも、（２）、（１）の順でもよい。（１）、（２）の工程は、交互に繰り返し行われてもよい。 First, (1) a step of rinsing after conducting particles 100a are dispersed in a polymer electrolyte solution, the polymer electrolyte is adsorbed on the surface of the conductive particles 100a, and then rinsed. Next, (2) a step of rinsing after dispersing the conductive particles 100a in a dispersion solution of insulating particles, adsorbing the insulating particles on the surface of the conductive particles 100a, is performed. Through these steps, insulating coated conductive particles 200 whose surfaces are coated with insulating particles 210 in which a polymer electrolyte and insulating particles are laminated can be manufactured. The steps (1) and (2) may be in the order of (1) and (2) or in the order of (2) and (1). The steps (1) and (2) may be repeated alternately.
　高分子電解質としては、例えば、水溶液中で電離し、荷電を有する官能基を主鎖又は側鎖に有する高分子を用いることができる。例えば、ポリアミン類等のように正荷電を帯びることのできる官能基を有する高分子化合物を用いることができ、樹脂粒子１０１の表面処理に用いられる前述のカチオン性ポリマーと同じものを用いることもできる。具体的には、ポリエチレンイミン（ＰＥＩ）、ポリアリルアミン塩酸塩（ＰＡＨ）、ポリジアリルジメチルアンモニウムクロリド（ＰＤＤＡ）、ポリビニルピリジン（ＰＶＰ）、ポリリジン、ポリアクリルアミド、これらの重合体を与える１種以上の単量体を重合して得られる共重合体等を用いることができる。電荷密度が高く、負の電荷を持った表面及び材料との結合力が強い観点から、ポリエチレンイミンを用いることが好ましい。 As the polymer electrolyte, for example, a polymer that is ionized in an aqueous solution and has a charged functional group in the main chain or side chain can be used. For example, a polymer compound having a positively charged functional group such as polyamines can be used, and the same cationic polymer as that used for the surface treatment of the resin particles 101 can be used. . Specifically, polyethyleneimine (PEI), polyallylamine hydrochloride (PAH), polydiallyldimethylammonium chloride (PDDA), polyvinylpyridine (PVP), polylysine, polyacrylamide, and one or more types of polymers that give these polymers. A copolymer or the like obtained by polymerizing the monomer can be used. Polyethyleneimine is preferably used from the viewpoint of high charge density and strong binding force to negatively charged surfaces and materials.
　上記（１）、（２）の工程を繰り返す方法は、交互積層法（Ｌａｙｅｒ－ｂｙ－Ｌａｙｅｒ　ａｓｓｅｍｂｌｙ）と呼ばれる。交互積層法は、Ｇ．Ｄｅｃｈｅｒらによって１９９２年に発表された有機薄膜を形成する方法である（Ｔｈｉｎ　Ｓｏｌｉｄ　Ｆｉｌｍｓ，２１０／２１１，ｐ８３１（１９９２））。Ｇ．Ｄｅｃｈｅｒらによって発表された方法によれば、正電荷を有するポリマー電解質（ポリカチオン）、及び、負電荷を有するポリマー電解質（ポリアニオン）の水溶液に基材（基板等）を交互に浸漬し、静電的引力によって基材上に吸着したポリカチオンとポリアニオンとの組が積層することで、複合膜（交互積層膜）が得られる。 The method of repeating the above steps (1) and (2) is called an alternating layering method (Layer-by-Layer assembly). The alternating lamination method is described in G. This is a method for forming an organic thin film published in 1992 by Decher et al. (Thin Solid Films, 210/211, p831 (1992)). G. According to the method published by Decher et al., A substrate (substrate, etc.) is alternately immersed in an aqueous solution of a polymer electrolyte (polycation) having a positive charge and a polymer electrolyte (polyanion) having a negative charge, A composite membrane (alternate laminated membrane) is obtained by laminating a set of polycations and polyanions adsorbed on a substrate by an attractive force.
　交互積層法では、静電的な引力によって、基材上に形成された材料の電荷と、溶液中の反対電荷を有する材料とが引き合うことにより膜成長する。このため、吸着が進行して電荷の中和が起こるとそれ以上の吸着が起こらなくなる。したがって、ある飽和点までに至れば、それ以上膜厚が増加することはない。Ｌｖｏｖらは交互積層法を微粒子に応用し、シリカ、チタニア、セリア等の各微粒子分散液を用いて、微粒子の表面電荷と反対電荷を有する高分子電解質を交互積層法で積層する方法を報告している（Ｌａｎｇｍｕｉｒ，Ｖｏｌ．１３，（１９９７）ｐ６１９５－６２０３）。Ｌｖｏｖによって報告された方法を用いると、負の表面電荷を有するシリカの微粒子と、その反対電荷を有するポリカチオンであるポリジアリルジメチルアンモニウムクロライド（ＰＤＤＡ）、ポリエチレンイミン（ＰＥＩ）等と、を交互に積層することで、シリカ微粒子と高分子電解質とが交互に積層された微粒子積層薄膜を形成することができる。 In the alternate lamination method, the film grows by attracting the charge of the material formed on the substrate and the material having the opposite charge in the solution by electrostatic attraction. For this reason, when adsorption proceeds and charge neutralization occurs, no further adsorption occurs. Therefore, when reaching a certain saturation point, the film thickness does not increase any more. Lvov et al. Applied an alternate lamination method to fine particles and reported a method of laminating a polymer electrolyte having a charge opposite to the surface charge of the fine particles using each fine particle dispersion such as silica, titania and ceria. (Langmuir, Vol. 13, (1997) p6195-6203). Using the method reported by Lvov, silica fine particles having a negative surface charge and polydiallyldimethylammonium chloride (PDDA), polyethyleneimine (PEI), and the like, which are polycations having the opposite charge, are alternately used. By laminating, a fine particle laminated thin film in which silica fine particles and polymer electrolyte are alternately laminated can be formed.
　以上に説明した第３実施形態に係る絶縁被覆導電粒子２００においても、第１実施形態と同様に、当該絶縁被覆導電粒子２００が配合された異方導電性接着剤を用いた接続構造体を高温高湿下に保存した場合であっても、導通信頼性が向上する。加えて、第１層１０４の外表面に設けられた絶縁性粒子２１０により、導電粒子１００ａの第１層１０４同士が接触しにくくなる。さらには、脱落した非導電性無機粒子１０２が金属によってコーティングされて形成される金属異物は、接着剤中に存在しにくい。したがって、絶縁被覆導電粒子２００同士が良好に導通しにくくなり、当該絶縁被覆導電粒子２００を用いた接続構造体等の絶縁信頼性も好適に向上する。 Also in the insulating coated conductive particles 200 according to the third embodiment described above, similarly to the first embodiment, the connection structure using the anisotropic conductive adhesive containing the insulating coated conductive particles 200 is heated at a high temperature. Even when stored under high humidity, the conduction reliability is improved. In addition, the insulating particles 210 provided on the outer surface of the first layer 104 make it difficult for the first layers 104 of the conductive particles 100a to contact each other. Furthermore, the foreign metal formed by coating the dropped non-conductive inorganic particles 102 with a metal is unlikely to exist in the adhesive. Therefore, it becomes difficult for the insulating coating conductive particles 200 to conduct well, and the insulation reliability of the connection structure using the insulating coating conductive particles 200 is also preferably improved.
　特に近年、ＣＯＧ実装用の異方導電性接着剤等には、約１０μｍの狭ピッチでの絶縁信頼性が求められている。第３実施形態に係る絶縁被覆導電粒子２００を用いることによって、このような絶縁信頼性を実現することができる。 Particularly in recent years, anisotropic conductive adhesives for COG mounting have been required to have insulation reliability at a narrow pitch of about 10 μm. Such insulation reliability can be realized by using the insulating coated conductive particles 200 according to the third embodiment.
　第３実施形態に係る絶縁被覆導電粒子２００における導電粒子としては、導電粒子１００ａに代えて、例えば、第２実施形態に係る導電粒子１００ｂ等を用いることができる。この場合、絶縁被覆導電粒子２００は、上記作用効果に加えて、第２実施形態に係る導電粒子１００ｂによる作用効果を奏することができる。 As the conductive particles in the insulating coated conductive particles 200 according to the third embodiment, for example, the conductive particles 100b according to the second embodiment can be used instead of the conductive particles 100a. In this case, the insulating coated conductive particles 200 can exhibit the effects of the conductive particles 100b according to the second embodiment in addition to the above effects.
（第４実施形態）
　以下では、第４実施形態に係る異方導電性接着剤について説明する。第４実施形態の説明において第１実施形態～第３実施形態と重複する記載は省略し、第１実施形態～第３実施形態と異なる部分を記載する。つまり、技術的に可能な範囲において、第４実施形態に第１実施形態～第３実施形態の記載を適宜用いてもよい。 (Fourth embodiment)
Below, the anisotropic conductive adhesive which concerns on 4th Embodiment is demonstrated. In the description of the fourth embodiment, the description overlapping with the first to third embodiments is omitted, and only parts different from the first to third embodiments are described. In other words, the descriptions of the first to third embodiments may be used as appropriate for the fourth embodiment within the technically possible range.
＜異方導電性接着剤＞
　第４実施形態に係る異方導電性接着剤は、第１実施形態に係る導電粒子１００ａと、当該導電粒子１００ａが分散された接着剤とを含有する。 <Anisotropic conductive adhesive>
The anisotropic conductive adhesive according to the fourth embodiment contains the conductive particles 100a according to the first embodiment and the adhesive in which the conductive particles 100a are dispersed.
　接着剤としては、例えば、熱反応性樹脂と硬化剤との混合物が用いられる。接着剤としては、例えば、エポキシ樹脂と潜在性硬化剤との混合物、及び、ラジカル重合性化合物と有機過酸化物との混合物が挙げられる。 As the adhesive, for example, a mixture of a heat-reactive resin and a curing agent is used. Examples of the adhesive include a mixture of an epoxy resin and a latent curing agent, and a mixture of a radical polymerizable compound and an organic peroxide.
　接着剤としては、ペースト状又はフィルム状の接着剤が用いられる。異方導電性接着剤をフィルム状に成形するために、フェノキシ樹脂、ポリエステル樹脂、ポリアミド樹脂、ポリエステル樹脂、ポリウレタン樹脂、（メタ）アクリル樹脂、ポリエステルウレタン樹脂等の熱可塑性樹脂が接着剤に配合されてもよい。 As the adhesive, a paste or film adhesive is used. In order to form the anisotropic conductive adhesive into a film, a thermoplastic resin such as phenoxy resin, polyester resin, polyamide resin, polyester resin, polyurethane resin, (meth) acrylic resin, polyester urethane resin is blended into the adhesive. May be.
　以上に説明した第４実施形態に係る異方導電性接着剤においても、第１実施形態と同様に、導通信頼性が向上する。加えて、樹脂粒子１０１から脱落する非導電性無機粒子１０２の数が低減されるので、複合粒子１０３に異常に成長した突起が発生しにくくなる。また、接着剤中に脱落した非導電性無機粒子１０２に起因して生成される金属異物の数が低減される。したがって、異方導電性接着剤中に分散された導電粒子１００ａ同士が導通しにくくなり、異方導電性接着剤の絶縁信頼性も向上する。 Also in the anisotropic conductive adhesive according to the fourth embodiment described above, the conduction reliability is improved as in the first embodiment. In addition, since the number of non-conductive inorganic particles 102 that fall off from the resin particles 101 is reduced, abnormally grown protrusions are hardly generated on the composite particles 103. In addition, the number of metallic foreign matters generated due to the non-conductive inorganic particles 102 dropped into the adhesive is reduced. Therefore, it becomes difficult for the conductive particles 100a dispersed in the anisotropic conductive adhesive to conduct, and the insulation reliability of the anisotropic conductive adhesive is also improved.
　第４実施形態に係る異方導電性接着剤における導電粒子としては、導電粒子１００ａに代えて、例えば、第２実施形態に係る導電粒子１００ｂ等を用いることができる。この場合、異方導電性接着剤は、第２実施形態に係る導電粒子１００ｂによる作用効果を奏することができる。導電粒子１００ａに代えて、絶縁被覆導電粒子２００を用いてもよい。この場合、異方導電性接着剤は、第３実施形態に係る導電粒子１００ｂによる作用効果を奏することができる。 As the conductive particles in the anisotropic conductive adhesive according to the fourth embodiment, for example, the conductive particles 100b according to the second embodiment can be used instead of the conductive particles 100a. In this case, the anisotropic conductive adhesive can achieve the effects of the conductive particles 100b according to the second embodiment. Insulating coated conductive particles 200 may be used instead of the conductive particles 100a. In this case, the anisotropic conductive adhesive can achieve the effects of the conductive particles 100b according to the third embodiment.
（第５実施形態）
　以下では、第５実施形態に係る接続構造体について説明する。第５実施形態の説明において第１実施形態～第４実施形態と重複する記載は省略し、第１実施形態～第４実施形態と異なる部分を記載する。つまり、技術的に可能な範囲において、第５実施形態に第１実施形態～第４実施形態の記載を適宜用いてもよい。 (Fifth embodiment)
Below, the connection structure concerning a 5th embodiment is explained. In the description of the fifth embodiment, the description overlapping with the first embodiment to the fourth embodiment is omitted, and only parts different from the first embodiment to the fourth embodiment are described. In other words, the descriptions of the first to fourth embodiments may be used as appropriate for the fifth embodiment within the technically possible range.
＜接続構造体＞
　第５実施形態に係る接続構造体について説明する。本実施形態に係る接続構造体は、第１回路電極を有する第１回路部材と、第２回路電極を有する第２回路部材と、第１回路部材と第２回路部材との間に配置され、上記導電粒子及び上記絶縁被覆導電粒子の少なくとも一方を含有する接続部と、を備えている。接続部は、第１回路電極と第２回路電極とが対向するように配置された状態で第１回路部材及び第２回路部材を互いに接続している。第１回路電極及び第２回路電極は、変形した状態の導電粒子又は絶縁被覆導電粒子を介して互いに電気的に接続されている。 <Connection structure>
A connection structure according to the fifth embodiment will be described. The connection structure according to the present embodiment is disposed between a first circuit member having a first circuit electrode, a second circuit member having a second circuit electrode, and the first circuit member and the second circuit member, A connecting portion containing at least one of the conductive particles and the insulating coated conductive particles. The connecting portion connects the first circuit member and the second circuit member to each other in a state where the first circuit electrode and the second circuit electrode are arranged to face each other. The first circuit electrode and the second circuit electrode are electrically connected to each other through the deformed conductive particles or the insulating coated conductive particles.
　次に、図６を参照しながら、第５実施形態に係る接続構造体を更に説明する。図６は、第５実施形態に係る接続構造体を示す模式断面図である。図６に示す接続構造体３００は、互いに対向する第１回路部材３１０及び第２回路部材３２０と、第１回路部材３１０と第２回路部材３２０との間に配置される接続部３３０とを備えている。接続構造体３００としては、液晶ディスプレイ、パーソナルコンピュータ、携帯電話、スマートフォン、タブレット等の携帯製品が挙げられる。 Next, the connection structure according to the fifth embodiment will be further described with reference to FIG. FIG. 6 is a schematic cross-sectional view showing a connection structure according to the fifth embodiment. A connection structure 300 illustrated in FIG. 6 includes a first circuit member 310 and a second circuit member 320 that face each other, and a connection portion 330 that is disposed between the first circuit member 310 and the second circuit member 320. ing. Examples of the connection structure 300 include portable products such as a liquid crystal display, a personal computer, a mobile phone, a smartphone, and a tablet.
　第１回路部材３１０は、回路基板（第１回路基板）３１１と、回路基板３１１の主面３１１ａ上に配置された回路電極（第１回路電極）３１２とを備える。第２回路部材３２０は、回路基板（第の回路基板）３２１と、回路基板３２１の主面３２１ａ上に配置された回路電極（第２回路電極）３２２とを備える。 The first circuit member 310 includes a circuit board (first circuit board) 311 and a circuit electrode (first circuit electrode) 312 disposed on the main surface 311a of the circuit board 311. The second circuit member 320 includes a circuit board (first circuit board) 321 and circuit electrodes (second circuit electrodes) 322 arranged on the main surface 321 a of the circuit board 321.
　回路部材３１０，３２０のうちの一方の具体例としては、ＩＣチップ（半導体チップ）、抵抗体チップ、コンデンサチップ、ドライバーＩＣ等のチップ部品；リジット型のパッケージ基板などが挙げられる。これらの回路部材は、回路電極を備えており、多数の回路電極を備えているものが一般的である。回路部材３１０，３２０のうちの他方（前記一方の回路部材が接続される回路部材）の具体例としては、金属配線を有するフレキシブルテープ基板、フレキシブルプリント配線板、インジウム錫酸化物（ＩＴＯ）が蒸着されたガラス基板等の配線基板などが挙げられる。例えば、フィルム状の異方導電性接着剤を用いることによって、これらの回路部材同士を効率的且つ高い接続信頼性をもって接続できる。例えば、第４実施形態に係る異方導電性接着剤は、微細な回路電極を多数備えるチップ部品の配線基板上へのＣＯＧ実装又はＣＯＦ実装に好適である。 Specific examples of one of the circuit members 310 and 320 include chip components such as an IC chip (semiconductor chip), a resistor chip, a capacitor chip, and a driver IC; a rigid-type package substrate. These circuit members are provided with circuit electrodes, and generally have many circuit electrodes. Specific examples of the other of the circuit members 310 and 320 (the circuit member to which the one circuit member is connected) include a flexible tape substrate having metal wiring, a flexible printed wiring board, and indium tin oxide (ITO). Examples thereof include a wiring substrate such as a glass substrate. For example, by using a film-like anisotropic conductive adhesive, these circuit members can be connected efficiently and with high connection reliability. For example, the anisotropic conductive adhesive according to the fourth embodiment is suitable for COG mounting or COF mounting on a wiring board of a chip component having many fine circuit electrodes.
　接続部３３０は、接着剤の硬化物３３２と、当該硬化物３３２に分散している絶縁被覆導電粒子２００とを備えている。接続部３３０としては、例えば、上記第４実施形態に記載されるフィルム状の異方導電性接着剤が用いられる。接続構造体３００においては、相対向する回路電極３１２と回路電極３２２とが、絶縁被覆導電粒子２００を介して電気的に接続されている。より具体的には、図６に示すとおり、絶縁被覆導電粒子２００における導電粒子１００ａが圧縮により変形し、回路電極３１２，３２２の双方に電気的に接続している。一方、導電粒子１００ａは、圧縮する方向に交差する方向において導電粒子１００ａ間に絶縁性粒子２１０が介在することにより、絶縁被覆導電粒子２００同士の絶縁性が維持される。したがって、狭ピッチ（例えば、１０μｍレベルのピッチ）での絶縁信頼性を更に向上させることができる。用途によっては絶縁被覆導電粒子２００の代わりに、絶縁被覆されていない導電粒子１００ａ、１００ｂを用いてもよい。 The connection portion 330 includes a cured product 332 of an adhesive and insulating coating conductive particles 200 dispersed in the cured product 332. As the connection part 330, for example, a film-like anisotropic conductive adhesive described in the fourth embodiment is used. In the connection structure 300, the circuit electrode 312 and the circuit electrode 322 that face each other are electrically connected via the insulating coating conductive particles 200. More specifically, as shown in FIG. 6, the conductive particles 100 a in the insulating coated conductive particles 200 are deformed by compression and are electrically connected to both the circuit electrodes 312 and 322. On the other hand, in the conductive particles 100a, the insulating particles 210 are interposed between the conductive particles 100a in the direction intersecting the compressing direction, so that the insulation between the insulating coated conductive particles 200 is maintained. Therefore, the insulation reliability at a narrow pitch (for example, a pitch of 10 μm level) can be further improved. Depending on the application, the conductive particles 100 a and 100 b that are not covered with insulation may be used instead of the insulating coated conductive particles 200.
　接続構造体３００は、回路電極３１２を有する第１回路部材３１０と、回路電極３２２を有する第２回路部材３２０と、を回路電極３１２と回路電極３２２とが相対向するように配置し、第１回路部材３１０と第２回路部材３２０との間に異方導電性接着剤を介在させ、これらを加熱及び加圧して回路電極３１２と回路電極３２２とを電気的に接続させることにより得られる。第１回路部材３１０及び第２回路部材３２０は、接着剤の硬化物３３２によって接着される。 In the connection structure 300, a first circuit member 310 having a circuit electrode 312 and a second circuit member 320 having a circuit electrode 322 are arranged such that the circuit electrode 312 and the circuit electrode 322 face each other, and It is obtained by interposing an anisotropic conductive adhesive between the circuit member 310 and the second circuit member 320, and heating and pressurizing them to electrically connect the circuit electrode 312 and the circuit electrode 322. The first circuit member 310 and the second circuit member 320 are bonded together by a cured product 332 of an adhesive.
＜接続構造体の製造方法＞
　第５実施形態に係る接続構造体の製造方法について、図７を参照しながら説明する。図７は、図６に示す接続構造体の製造方法の一例を説明するための模式断面図である。第５実施形態では、異方導電性接着剤を熱硬化させて接続構造体を製造する。 <Method for manufacturing connection structure>
A method for manufacturing a connection structure according to the fifth embodiment will be described with reference to FIG. FIG. 7 is a schematic cross-sectional view for explaining an example of the manufacturing method of the connection structure shown in FIG. In the fifth embodiment, the anisotropic conductive adhesive is thermoset to produce a connection structure.
　まず、第１回路部材３１０と、異方導電性接着剤３３０ａとを用意する。本実施形態では、異方導電性接着剤３３０ａとして、フィルム状に成形してなる接着剤フィルム（異方導電性接着剤フィルム）を用いる。異方導電性接着剤３３０ａは、絶縁被覆導電粒子２００と、絶縁性の接着剤３３２ａとを含有している。 First, a first circuit member 310 and an anisotropic conductive adhesive 330a are prepared. In the present embodiment, an adhesive film (anisotropic conductive adhesive film) formed into a film shape is used as the anisotropic conductive adhesive 330a. The anisotropic conductive adhesive 330a contains the insulating coating conductive particles 200 and the insulating adhesive 332a.
　次に、異方導電性接着剤３３０ａを第１回路部材３１０の主面３１１ａ（回路電極３１２が形成されている面）上に載せる。そして、図７（ａ）に示すように、異方導電性接着剤３３０ａを方向Ａ及び方向Ｂに沿って加圧する。これにより、図７（ｂ）に示すように、異方導電性接着剤３３０ａを第１回路部材３１０に積層する。 Next, the anisotropic conductive adhesive 330a is placed on the main surface 311a of the first circuit member 310 (the surface on which the circuit electrode 312 is formed). Then, as shown in FIG. 7A, the anisotropic conductive adhesive 330 a is pressurized along the direction A and the direction B. Thereby, as shown in FIG. 7B, the anisotropic conductive adhesive 330 a is laminated on the first circuit member 310.
　次いで、図７（ｃ）に示すように、回路電極３１２と回路電極３２２とが相対向するように、第２回路部材３２０を異方導電性接着剤３３０ａ上に載せる。そして、異方導電性接着剤３３０ａを加熱しながら、図７（ｃ）に示される方向Ａ及び方向Ｂに沿って全体（第１回路部材３１０及び第２回路部材３２０）を加圧する。 Next, as shown in FIG. 7C, the second circuit member 320 is placed on the anisotropic conductive adhesive 330a so that the circuit electrode 312 and the circuit electrode 322 face each other. And the whole (the 1st circuit member 310 and the 2nd circuit member 320) is pressurized along the direction A and the direction B shown by FIG.7 (c), heating the anisotropic conductive adhesive 330a.
　加熱により異方導電性接着剤３３０ａが硬化して接続部３３０が形成され、図６に示すような接続構造体３００が得られる。異方導電性接着剤はペースト状であってもよい。 The anisotropic conductive adhesive 330a is cured by heating to form the connection portion 330, and a connection structure 300 as shown in FIG. 6 is obtained. The anisotropic conductive adhesive may be in the form of a paste.
　以上に説明した第５実施形態に係る接続構造体３００においては、接続部３３０内に第３実施形態に係る絶縁被覆導電粒子２００が含まれている。上記接続構造体３００によれば、絶縁被覆導電粒子２００を介して回路電極３１２と回路電極３２２とが良好に電気的に接続される。このため、回路電極３１２及び回路電極３２２の面積が小さく、且つ、回路電極３１２、３２２の間に捕捉される絶縁被覆導電粒子２００の個数が少ない場合であっても、長期間にわたって優れた導通信頼性が発揮される。加えて、絶縁被覆導電粒子２００が絶縁性粒子２１０を有することにより、接続部３３０内における絶縁被覆導電粒子２００の第１層１０４同士が接触しにくくなる。このため、例えば、回路電極３１２内（回路電極３２２内）に設けられる電極同士のピッチが例えば、１０μｍ以下である場合であっても、接続部３３０内の絶縁被覆導電粒子２００同士が導通しにくくなり、接続構造体３００の絶縁信頼性も好適に向上する。 In the connection structure 300 according to the fifth embodiment described above, the insulating coating conductive particles 200 according to the third embodiment are included in the connection portion 330. According to the connection structure 300, the circuit electrode 312 and the circuit electrode 322 are electrically connected satisfactorily through the insulating coating conductive particles 200. For this reason, even when the area of the circuit electrode 312 and the circuit electrode 322 is small and the number of the insulating coating conductive particles 200 captured between the circuit electrodes 312 and 322 is small, excellent conduction reliability over a long period of time. Sex is demonstrated. In addition, since the insulating coated conductive particles 200 include the insulating particles 210, the first layers 104 of the insulating coated conductive particles 200 in the connection portion 330 are less likely to contact each other. For this reason, for example, even if the pitch between the electrodes provided in the circuit electrode 312 (in the circuit electrode 322) is, for example, 10 μm or less, the insulating coated conductive particles 200 in the connection portion 330 are difficult to conduct. Thus, the insulation reliability of the connection structure 300 is also preferably improved.
　以上、本発明の実施形態について説明したが、本発明は上記実施形態のみに限定されるものではない。例えば、上記実施形態では非導電性無機粒子の平均粒径は２５ｎｍ～１２０ｎｍであるが、本発明はこれに限られない。同様に、樹脂粒子の平均粒径は必ずしも１～１０μｍでなくてもよい。 As mentioned above, although embodiment of this invention was described, this invention is not limited only to the said embodiment. For example, in the above embodiment, the average particle diameter of the non-conductive inorganic particles is 25 nm to 120 nm, but the present invention is not limited to this. Similarly, the average particle size of the resin particles is not necessarily 1 to 10 μm.
　以下、実施例及び比較例を挙げて本発明の内容をより具体的に説明する。なお、本発明は下記実施例に限定されるものではない。 Hereinafter, the contents of the present invention will be described more specifically with reference to examples and comparative examples. In addition, this invention is not limited to the following Example.
＜実施例１＞
［導電粒子の作製］
（工程ａ）樹脂粒子表面のカチオン性ポリマーによる被覆
　平均粒径３．０μｍの架橋ポリスチレン粒子（株式会社日本触媒製、商品名「ソリオスター」）２ｇを、平均分子量７万（Ｍ．Ｗ．７万）の３０質量％ポリエチレンイミン水溶液（和光純薬工業株式会社製）３ｇを純水１００ｍｌに溶解した水溶液に加え、室温で１５分間攪拌した。次いで、φ３μｍのメンブレンフィルタ（メルクミリポア社製）を用いた濾過により、樹脂粒子を取り出した。メンブレンフィルタ上の樹脂粒子を２００ｇの超純水で２回洗浄し、吸着していないポリエチレンイミンを除去して、ポリエチレンイミンが吸着した樹脂粒子を得た。 <Example 1>
[Preparation of conductive particles]
(Step a) Coating of resin particle surface with cationic polymer 2 g of crosslinked polystyrene particles having an average particle size of 3.0 μm (trade name “Soliostar”, manufactured by Nippon Shokubai Co., Ltd.) were added to an average molecular weight of 70,000 (MW 7). 10 g of a 30% by mass polyethyleneimine aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) was added to an aqueous solution dissolved in 100 ml of pure water and stirred at room temperature for 15 minutes. Subsequently, the resin particles were taken out by filtration using a φ3 μm membrane filter (manufactured by Merck Millipore). The resin particles on the membrane filter were washed twice with 200 g of ultrapure water to remove non-adsorbed polyethyleneimine to obtain resin particles adsorbed with polyethyleneimine.
（工程ｂ）非導電性無機粒子表面の疎水化処理剤による被覆
　非導電性無機粒子として、平均粒径６０ｎｍの気相法親水性球状シリカ粉末を用いた。この球状シリカ粉末１００ｇを振動流動層装置（中央化工機株式会社製、商品名「振動流動層装置ＶＵＡ－１５型」）に収容した。次に、吸引ブロワーにより循環させた空気で球状シリカを流動化させながら水１．５ｇを噴霧して５分間流動混合させた。次に、ＨＭＤＳ（ヘキサメチレンジシラザン）（モメンティブ・パフォーマンス・マテリアルズ・ジャパン合同会社製、商品名「ＴＳＬ－８８０２」）２．５ｇを噴霧し、３０分間流動混合した。得られた疎水性球状シリカ微粉体の疎水化度を、メタノール滴定法によって測定した。疎水化度は以下の方法で測定し、非導電性無機粒子の疎水化度は７０％であった。 (Step b) Coating of non-conductive inorganic particles with a hydrophobizing agent The vapor-phase hydrophilic spherical silica powder having an average particle size of 60 nm was used as non-conductive inorganic particles. 100 g of this spherical silica powder was placed in a vibrating fluidized bed apparatus (manufactured by Chuo Kako Co., Ltd., trade name “vibrating fluidized bed apparatus VUA-15 type”). Next, 1.5 g of water was sprayed and mixed for 5 minutes while fluidizing the spherical silica with air circulated by a suction blower. Next, 2.5 g of HMDS (hexamethylene disilazane) (product name “TSL-8802” manufactured by Momentive Performance Materials Japan GK) was sprayed and mixed by fluidization for 30 minutes. The degree of hydrophobicity of the obtained hydrophobic spherical silica fine powder was measured by a methanol titration method. The degree of hydrophobicity was measured by the following method, and the degree of hydrophobicity of the non-conductive inorganic particles was 70%.
（工程ｃ）樹脂粒子表面への非導電性無機粒子の静電気的接着工程
　ポリエチレンイミンが吸着した樹脂粒子２ｇをメタノールに加え、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながら室温で５分間攪拌した。その後、ＨＭＤＳにより疎水化された球状シリカ粉末０．０５ｇを上記メタノールに加え、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながらさらに室温で５分間攪拌した。これにより、シリカが静電気により吸着された樹脂粒子（粒子Ａ）を得た。シリカが静電気により吸着された粒子Ａは２．０５ｇであった。 (Process c) Electrostatic adhesion process of non-conductive inorganic particles to the surface of resin particles 2 g of resin particles adsorbed with polyethyleneimine are added to methanol and stirred for 5 minutes at room temperature while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. did. Thereafter, 0.05 g of spherical silica powder hydrophobized with HMDS was added to the methanol, and the mixture was further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Thereby, resin particles (particle A) in which silica was adsorbed by static electricity were obtained. The particle A in which silica was adsorbed by static electricity was 2.05 g.
（工程ｄ）パラジウム触媒付与工程
　粒子Ａ２．０５ｇを、ｐＨ１．０に調整され、パラジウム触媒（日立化成株式会社製、商品名「ＨＳ２０１」）を２０質量％含有するパラジウム触媒化液１００ｍＬに添加した。その後、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながら３０℃で３０分間攪拌した。次に、φ３μｍのメンブレンフィルタ（メルクミリポア社製）で濾過した後、水洗を行うことでパラジウム触媒を粒子Ａの表面に吸着させた。その後、ｐＨ６．０に調整された０．５質量％ジメチルアミンボラン液に粒子Ａを添加し、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながら６０℃で５分間攪拌し、パラジウム触媒が固着化された粒子Ｂ２．０５ｇを得た。そして、２０ｍＬの蒸留水に、パラジウム触媒が固着化された粒子Ｂ２．０５ｇを浸漬した後、粒子Ｂを超音波分散することで、樹脂粒子分散液を得た。 (Process d) Palladium catalyst provision process 2.05g of particle | grains A was adjusted to pH1.0, and it added to 100 mL of palladium catalyst formation liquid containing 20 mass% of palladium catalysts (The Hitachi Chemical Co., Ltd. make, brand name "HS201"). . Then, it stirred for 30 minutes at 30 degreeC, irradiating the ultrasonic wave of resonance frequency 28kHz and output 100W. Next, after filtering through a 3 μm membrane filter (manufactured by Merck Millipore), the palladium catalyst was adsorbed on the surface of the particles A by washing with water. Thereafter, particles A are added to 0.5% by mass dimethylamine borane solution adjusted to pH 6.0, and stirred for 5 minutes at 60 ° C. while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W, and the palladium catalyst is fixed. 2.05 g of modified particles B were obtained. And after immersing 2.05 g of particle | grains B in which the palladium catalyst was fixed in 20 mL distilled water, the particle | grains B were ultrasonically dispersed and the resin particle dispersion liquid was obtained.
（工程ｅ）第１層のａ層の形成
　工程ｄで得た粒子Ｂ分散液を、８０℃に加温した水１０００ｍＬで希釈した後、めっき安定剤として１ｇ／Ｌの硝酸ビスマス水溶液を１ｍＬ添加した。次に、粒子Ｂ分散液に、下記組成（下記成分を含む水溶液であり、１ｇ／Ｌの硝酸ビスマス水溶液をめっき液１Ｌあたり１ｍＬ添加している。以下同様）のａ層形成用の無電解ニッケルめっき液８０ｍＬを５ｍＬ／分の滴下速度で滴下した。滴下終了後、１０分間経過した後に、めっき液を加えた分散液を濾過した。濾過物を水で洗浄した後、８０℃の真空乾燥機で乾燥した。このようにして、表１－１に示す８０ｎｍの膜厚のニッケル－リン合金被膜からなるａ層を有する粒子Ｃを形成した。ａ層を形成することにより得た粒子Ｃは、４．０５ｇであった。第１層のａ層形成用の無電解ニッケルめっき液の組成は以下の通りである。
　　硫酸ニッケル・・・・・・・・・・・・４００ｇ／Ｌ
　　次亜リン酸ナトリウム・・・・・・・・１５０ｇ／Ｌ
　　クエン酸ナトリウム・・・・・・・・・１２０ｇ／Ｌ
　　硝酸ビスマス水溶液（１ｇ／Ｌ）・・・１ｍＬ／Ｌ (Step e) Formation of layer a of first layer After the particle B dispersion obtained in step d is diluted with 1000 mL of water heated to 80 ° C., 1 mL of 1 g / L bismuth nitrate aqueous solution is added as a plating stabilizer. did. Next, electroless nickel for forming a layer having the following composition (an aqueous solution containing the following components and 1 mL of 1 g / L bismuth nitrate aqueous solution per liter of plating solution; the same applies hereinafter) to the particle B dispersion. 80 mL of plating solution was added dropwise at a dropping rate of 5 mL / min. After 10 minutes had elapsed after the completion of the dropping, the dispersion with the plating solution added was filtered. The filtrate was washed with water and then dried with a vacuum dryer at 80 ° C. In this way, particles C having an a layer made of a nickel-phosphorus alloy film with a thickness of 80 nm shown in Table 1-1 were formed. The particle C obtained by forming the a layer was 4.05 g. The composition of the electroless nickel plating solution for forming the first layer a is as follows.
Nickel sulfate ... 400g / L
Sodium hypophosphite ... 150g / L
Sodium citrate ... 120g / L
Bismuth nitrate aqueous solution (1 g / L) ... 1 mL / L
（工程ｆ）第１層のｂ層の形成
　工程ｅで得た粒子Ｃ４．０５ｇを、水洗及び濾過した後、７０℃に加温した水１０００ｍＬに分散させた。この分散液に、めっき安定剤として１ｇ／Ｌの硝酸ビスマス水溶液を１ｍＬ添加した。次いで、下記組成のｂ層形成用の無電解ニッケルめっき液２０ｍＬを５ｍＬ／分の滴下速度で滴下した。滴下終了後、１０分間経過した後に、めっき液を加えた分散液を濾過した。濾過物を水で洗浄した後、８０℃の真空乾燥機で乾燥した。このようにして、表１－１に示す２０ｎｍの膜厚のニッケル－リン合金被膜からなるｂ層を有する粒子Ｄ（導電粒子）を形成した。ｂ層を形成することにより得た粒子Ｄは、４．５５ｇであった。第１層のｂ層形成用の無電解ニッケルめっき液の組成は以下の通りである。
　　硫酸ニッケル・・・・・・・・・・・・４００ｇ／Ｌ
　　次亜リン酸ナトリウム・・・・・・・・１５０ｇ／Ｌ
　　酒石酸ナトリウム・２水和物・・・・・６０ｇ／Ｌ
　　硝酸ビスマス水溶液（１ｇ／Ｌ）・・・１ｍＬ／Ｌ (Step f) Formation of b layer of first layer 4.05 g of particles C obtained in step e were washed with water and filtered, and then dispersed in 1000 mL of water heated to 70 ° C. To this dispersion, 1 mL of a 1 g / L bismuth nitrate aqueous solution was added as a plating stabilizer. Subsequently, 20 mL of electroless nickel plating solution for b layer formation of the following composition was dripped at the dripping speed | rate of 5 mL / min. After 10 minutes had elapsed after the completion of the dropping, the dispersion with the plating solution added was filtered. The filtrate was washed with water and then dried with a vacuum dryer at 80 ° C. In this way, particles D (conductive particles) having a b layer made of a nickel-phosphorus alloy film with a thickness of 20 nm shown in Table 1-1 were formed. The particle D obtained by forming the b layer was 4.55 g. The composition of the electroless nickel plating solution for forming the b layer of the first layer is as follows.
Nickel sulfate ... 400g / L
Sodium hypophosphite ... 150g / L
Sodium tartrate dihydrate ... 60g / L
Bismuth nitrate aqueous solution (1 g / L) ... 1 mL / L
［導電粒子の評価］
　下記の項目に基づき導電粒子、もしくは導電粒子に含まれる樹脂粒子及び非導電性無機粒子を評価した。結果を表１－１及び表１－２に示す。 [Evaluation of conductive particles]
Based on the following items, conductive particles, or resin particles and non-conductive inorganic particles contained in the conductive particles were evaluated. The results are shown in Table 1-1 and Table 1-2.
（疎水化度（％））
　導電粒子の疎水化度を以下の方法により測定した。まず、イオン交換水５０ｍｌ、試料（導電粒子）０．２ｇをビーカーに入れ、マグネティックスターラーで攪拌しながらビュレットからメタノールを滴下する。ビーカー内のメタノール濃度が増加するにつれ粉体は徐々に沈降していき、その全量が沈んだ終点におけるメタノール－水混合溶液中のメタノールの質量分率を、導電粒子の疎水化度（％）とした。 (Hydrophobicity (%))
The degree of hydrophobicity of the conductive particles was measured by the following method. First, 50 ml of ion exchange water and 0.2 g of a sample (conductive particles) are put in a beaker, and methanol is dropped from a burette while stirring with a magnetic stirrer. As the methanol concentration in the beaker increases, the powder gradually settles, and the mass fraction of methanol in the methanol-water mixed solution at the end point when the total amount of the powder settles is expressed as the hydrophobicity (%) of the conductive particles. did.
（非導電性無機粒子の平均粒径）
　非導電性無機粒子の粒径は、まず、ＳＥＭ（株式会社日立ハイテクノロジーズ製、商品名「Ｓ－４８００」）により１０万倍で観察して得られる画像を解析し、粒子５００個のそれぞれの面積を測定する。次に、粒子を円に換算した場合の直径を、非導電性無機粒子の平均粒径として算出した。また、得られた平均粒径に対する、粒径の標準偏差の比をパーセンテージで算出し、ＣＶとした。 (Average particle size of non-conductive inorganic particles)
First, the particle size of the non-conductive inorganic particles was determined by analyzing an image obtained by observing at a magnification of 100,000 times with an SEM (trade name “S-4800” manufactured by Hitachi High-Technologies Corporation). Measure the area. Next, the diameter when the particles were converted into a circle was calculated as the average particle diameter of the non-conductive inorganic particles. Further, the ratio of the standard deviation of the particle diameter to the obtained average particle diameter was calculated as a percentage, and was defined as CV.
（ゼータ電位の測定）
　測定対象となる各種粒子のゼータ電位は、以下の方法により測定した。ゼータ電位の測定には、Ｚｅｔａｓｉｚｅｒ　ＺＳ（Ｍａｌｖｅｒｎ　Ｉｎｓｔｒｕｍｅｎｔｓ社製、商品名）を用いた。まず、測定対象となる各種粒子が約０．０２質量％になるように分散体を希釈した。そして、メタノールのみ、ｐＨ１、ｐｈ７およびｐＨ１０．５のメタノールとイオン交換水の混合溶媒の合計４条件におけるゼータ電位を測定した。メタノールとイオン交換水の混合溶媒において、メタノールの割合を１０質量％とし、ｐＨは、硫酸あるいは水酸化カリウムにより調整した。上記ゼータ電位の測定は、測定対象となる粒子毎に行った。 (Measurement of zeta potential)
The zeta potential of various particles to be measured was measured by the following method. For the zeta potential measurement, Zetasizer ZS (trade name, manufactured by Malvern Instruments) was used. First, the dispersion was diluted so that various particles to be measured were about 0.02% by mass. Then, the zeta potential was measured under a total of four conditions including methanol alone, pH 1, ph7 and pH 10.5 methanol and a mixed solvent of ion exchange water. In the mixed solvent of methanol and ion-exchanged water, the proportion of methanol was 10% by mass, and the pH was adjusted with sulfuric acid or potassium hydroxide. The zeta potential was measured for each particle to be measured.
（膜厚及び成分の評価）
　得られた導電粒子の中心付近を通るようにウルトラミクロトーム法で断面を切り出した。この断面を、ＴＥＭ（日本電子株式会社製、商品名「ＪＥＭ－２１００Ｆ」）を用いて２５万倍の倍率で観察した。得られた画像から、第１層のａ層、ｂ層及び第２層の断面積を見積り、その断面積から第１層のａ層、ｂ層及び第２層の膜厚を算出した（実施例１においては、第２層が形成されていないことから、第１層のａ層、ｂ層の膜厚のみを測定の対象とした）。断面積に基づく各層の膜厚の算出では、幅５００ｎｍの断面における各層の断面積を画像解析により読み取り、幅５００ｎｍの長方形に換算した場合の高さを各層の膜厚として算出した。表１－１には、１０個の導電粒子について算出した膜厚の平均値を示した。このとき、第１層のａ層、ｂ層を区別しづらい場合には、ＴＥＭに付属するＥＤＸ（日本電子株式会社製、商品名「ＪＥＤ－２３００」）による成分分析により、第１層のａ層、ｂ層を明確に区別することで、それぞれの断面積を見積もり、膜厚を計測した。ＥＤＸマッピングデータから、第１層のａ層、ｂ層における元素の含有量（純度）を算出した。薄膜切片状のサンプル（導電粒子の断面試料）の作製方法の詳細、ＥＤＸによるマッピングの方法の詳細、及び、各層における元素の含有量の算出方法の詳細については後述する。 (Evaluation of film thickness and components)
A cross section was cut out by an ultramicrotome method so as to pass through the vicinity of the center of the obtained conductive particles. This cross section was observed at a magnification of 250,000 times using TEM (trade name “JEM-2100F” manufactured by JEOL Ltd.). From the obtained image, the cross-sectional areas of the a-layer, b-layer and second layer of the first layer were estimated, and the film thicknesses of the a-layer, b-layer and second layer of the first layer were calculated from the cross-sectional areas (implementation) In Example 1, since the second layer was not formed, only the thicknesses of the a layer and the b layer of the first layer were measured. In the calculation of the film thickness of each layer based on the cross-sectional area, the cross-sectional area of each layer in the cross section with a width of 500 nm was read by image analysis, and the height when converted into a rectangle with a width of 500 nm was calculated as the film thickness of each layer. Table 1-1 shows the average values of the film thicknesses calculated for 10 conductive particles. At this time, if it is difficult to distinguish between the first layer a and the b layer, component analysis by EDX (trade name “JED-2300”, manufactured by JEOL Ltd.) attached to the TEM is used. By clearly distinguishing the layer and the b layer, the respective cross-sectional areas were estimated and the film thickness was measured. From the EDX mapping data, the content (purity) of the element in the first layer a and b was calculated. Details of a method for producing a sample in the form of a thin film (cross-sectional sample of conductive particles), details of a mapping method by EDX, and details of a method for calculating the content of elements in each layer will be described later.
（樹脂粒子表面に吸着した非導電性無機粒子の評価）
｛非導電性無機粒子の被覆率｝
　工程ｃと工程ｄとの後に得た、粒子Ａおよび粒子Ｂの正投影面において、粒子Ａおよび粒子Ｂの直径の１／２の直径を有する同心円内に存在する非導電性無機粒子による被覆率をそれぞれ算出した。具体的には、粒子ＡおよびＢの正投影面における粒子Ａ、Ｂの直径の１／２の直径を有する同心円内において、非導電性無機粒子と樹脂粒子とを画像解析により区別した。そして、同心円内に存在する非導電性無機粒子の面積の割合を算出し、当該割合を非導電性無機粒子の被覆率とした。粒子Ａと粒子Ｂとにおけるシリカ粒子の被覆率をそれぞれ算出することで、工程ｄ（パラジウム触媒付与工程）が、非導電性無機粒子の樹脂粒子表面への吸着性に与える影響を評価した。 (Evaluation of non-conductive inorganic particles adsorbed on the surface of resin particles)
{Coverage of non-conductive inorganic particles}
Coverage ratio of non-conductive inorganic particles present in concentric circles having a diameter half that of particles A and B on the orthographic projection surfaces of particles A and B obtained after step c and step d Was calculated respectively. Specifically, the non-conductive inorganic particles and the resin particles were distinguished by image analysis in a concentric circle having a diameter ½ of the diameter of the particles A and B on the orthographic projection surfaces of the particles A and B. And the ratio of the area of the nonelectroconductive inorganic particle which exists in a concentric circle was computed, and the said ratio was made into the coverage of the nonelectroconductive inorganic particle. The influence which the process d (palladium catalyst provision process) has on the adsorptivity to the resin particle surface of a nonelectroconductive inorganic particle was evaluated by calculating the coverage of the silica particle in the particle A and the particle B, respectively.
　具体的には、非導電性無機粒子の被覆率は、粒子Ａおよび粒子ＢをそれぞれＳＥＭにより３万倍で観察して得られる画像をもとに評価した。図８に、実施例１における工程ｄの後の粒子Ｂを観察したＳＥＭ画像を示す。 Specifically, the coverage of the non-conductive inorganic particles was evaluated based on images obtained by observing the particles A and B with a SEM at 30,000 times. In FIG. 8, the SEM image which observed the particle | grains B after the process d in Example 1 is shown.
｛非導電性無機粒子の直径と数｝
　工程ｃと工程ｄとの後に得た、粒子Ａおよび粒子Ｂの正投影面において、粒子Ａおよび粒子Ｂの直径の１／２の直径を有する同心円内に存在する非導電性無機粒子の直径と数とをそれぞれ算出した。粒子Ａと粒子Ｂにおける非導電性無機粒子の数をそれぞれ算出することで、工程ｄ（パラジウム触媒付与工程）が、非導電性無機粒子の樹脂粒子表面への吸着性に与える影響を評価した。 {Diameter and number of non-conductive inorganic particles}
The diameter of the non-conductive inorganic particles present in the concentric circles having a diameter half that of the particles A and B in the orthographic projection planes of the particles A and B obtained after the steps c and d. Numbers were calculated respectively. By calculating the number of nonconductive inorganic particles in each of particles A and B, the effect of step d (palladium catalyst application step) on the adsorptivity of the nonconductive inorganic particles to the resin particle surface was evaluated.
　具体的には、シリカ粒子の数は、粒子Ａおよび粒子ＢをＳＥＭにより１０万倍で観察して得られる画像をもとに評価した。各非導電性無機粒子の面積を測定し、その面積と同一の面積を有する真円の直径を非導電性無機粒子の直径として算出した。表１－２に示した直径の範囲に基づいて非導電性無機粒子を分類し、それぞれの範囲における非導電性無機粒子の個数を求めた。図９に、実施例１における工程ｄの後の粒子Ｂを観察したＳＥＭ画像を示す。図９は、粒子Ｂの直径の１／２の直径を有する同心円内の一部分である。 Specifically, the number of silica particles was evaluated based on images obtained by observing particles A and particles B with a SEM at a magnification of 100,000 times. The area of each non-conductive inorganic particle was measured, and the diameter of a perfect circle having the same area as that area was calculated as the diameter of the non-conductive inorganic particle. Non-conductive inorganic particles were classified based on the diameter ranges shown in Table 1-2, and the number of non-conductive inorganic particles in each range was determined. In FIG. 9, the SEM image which observed the particle | grains B after the process d in Example 1 is shown. FIG. 9 is a portion within a concentric circle having a diameter that is 1/2 the diameter of particle B. FIG.
（導電粒子の表面に形成された突起の評価）
｛突起の被覆率｝
　導電粒子をＳＥＭにより３万倍で観察して得られるＳＥＭ画像をもとに、導電粒子表面における突起による被覆率（面積の割合）を算出した。具体的には、導電粒子の正投影面における導電粒子の直径の１／２の直径を有する同心円内において突起形成部と平坦部とを画像解析により区別した。そして、同心円内に存在する突起形成部の面積の割合を算出し、当該割合を突起の被覆率とした。図１０に、実施例１における粒子ＤをＳＥＭにより観察した結果を示す。 (Evaluation of protrusions formed on the surface of conductive particles)
{Protrusion coverage}
Based on the SEM image obtained by observing the conductive particles with an SEM at a magnification of 30,000, the coverage (area ratio) of the protrusions on the surface of the conductive particles was calculated. Specifically, the projection forming part and the flat part were distinguished from each other by image analysis in a concentric circle having a diameter ½ of the diameter of the conductive particle on the orthographic projection surface of the conductive particle. And the ratio of the area of the protrusion formation part which exists in a concentric circle was computed, and the said ratio was made into the coverage of a protrusion. In FIG. 10, the result of having observed the particle | grains D in Example 1 by SEM is shown.
｛突起の直径と数｝
　導電粒子の正投影面において、導電粒子の直径の１／２の直径を有する同心円内に存在する突起の直径と数とを算出した。 {Diameter and number of protrusions}
On the orthographic projection surface of the conductive particles, the diameter and number of protrusions existing in concentric circles having a diameter that is 1/2 the diameter of the conductive particles were calculated.
　具体的には、導電粒子をＳＥＭにより１０万倍で観察して得られる画像を解析し、突起の輪郭を画定した。次に、突起の面積（突起間の谷により区切られる突起の輪郭の面積）を測定し、その面積と同一の面積を有する真円の直径を突起の直径（外径）として算出した。図１１に、実施例１における粒子ＤをＳＥＭにより観察した結果を示す。 Specifically, an image obtained by observing the conductive particles with a SEM at a magnification of 100,000 was analyzed to define the outline of the protrusion. Next, the area of the protrusion (the area of the outline of the protrusion divided by the valley between the protrusions) was measured, and the diameter of a perfect circle having the same area as the area was calculated as the diameter (outer diameter) of the protrusion. In FIG. 11, the result of having observed the particle | grains D in Example 1 by SEM is shown.
　表１－２に示した直径の範囲に基づいて突起を分類し、それぞれの範囲における突起の数を求めた。図１１は、粒子Ｄの直径の１／２の直径を有する同じ円内の一部分である。 The projections were classified based on the diameter ranges shown in Table 1-2, and the number of projections in each range was determined. FIG. 11 is a portion within the same circle having a diameter that is 1/2 the diameter of particle D. FIG.
（導電粒子の断面試料の作製方法）
　導電粒子の断面試料の作製方法の詳細について説明する。導電粒子の断面からＴＥＭ分析及びＳＴＥＭ／ＥＤＸ分析するための６０ｎｍ±２０ｎｍの厚さを有する断面試料（以下、「ＴＥＭ測定用の薄膜切片」という）を、ウルトラミクロトーム法を用いて下記のとおり作製した。 (Method for producing cross-sectional sample of conductive particles)
Details of a method for manufacturing a cross-sectional sample of conductive particles will be described. A cross-sectional sample having a thickness of 60 nm ± 20 nm for conducting TEM analysis and STEM / EDX analysis from the cross section of the conductive particles (hereinafter referred to as “thin film section for TEM measurement”) is prepared as follows using an ultramicrotome method. did.
　安定して薄膜化加工するため、導電粒子を注型樹脂に分散させた。具体的には、ビスフェノールＡ型液状エポキシ樹脂と、ブチルグリシジルエーテルと、その他エポキシ樹脂との混合物（リファインテック株式会社製、商品名「エポマウント主剤２７－７７１」）１０ｇにジエチレントリアミン（リファインテック株式会社製、商品名「エポマウント硬化剤２７－７７２」）１．０ｇを混合した。スパチュラを用いて攪拌し、均一に混合されたことを目視にて確認した。この混合物３ｇに乾燥済みの導電粒子０．５ｇを加えた後、スパチュラを用いて均一になるまで攪拌した。導電粒子を含む混合物を樹脂注型用の型（Ｄ．Ｓ．Ｋ　堂阪イーエム株式会社製、商品名「シリコーン包埋板ＩＩ型」）に流し込み、常温（室温）下で２４時間静置した。注型樹脂が固まったことを確認し、導電粒子の樹脂注型物を得た。 Conductive particles were dispersed in the casting resin for stable thinning. Specifically, 10 g of a mixture of bisphenol A liquid epoxy resin, butyl glycidyl ether, and other epoxy resin (Refinetech Co., Ltd., trade name “Epomount Main Agent 27-771”) is mixed with diethylenetriamine (Refinetech Corporation). (Product name “Epomount Curing Agent 27-772”) 1.0 g was mixed. It stirred using the spatula and it confirmed visually that it mixed uniformly. After adding 0.5 g of dried conductive particles to 3 g of this mixture, the mixture was stirred with a spatula until uniform. The mixture containing the conductive particles was poured into a mold for resin casting (DSK, manufactured by Dosaka EM Co., Ltd., trade name “silicone embedding plate type II”), and allowed to stand at room temperature (room temperature) for 24 hours. . After confirming that the casting resin was hardened, a resin casting of conductive particles was obtained.
　ウルトラミクロトーム（ライカマイクロシステムズ株式会社製、商品名「ＥＭ－ＵＣ６」）を用いて、導電粒子が含まれる樹脂注型物から、ＴＥＭ測定用の薄膜切片を作製した。ＴＥＭ測定用の薄膜切片を作製する際には、まず、ウルトラミクロトームの装置本体に固定したガラス製のナイフを用いて、図１２（ａ）に示すように、ＴＥＭ測定用の薄膜切片を切り出せる形状になるまで樹脂注型物の先端をトリミング加工した。 Using an ultramicrotome (trade name “EM-UC6” manufactured by Leica Microsystems Co., Ltd.), a thin film slice for TEM measurement was prepared from a resin cast containing conductive particles. When producing a thin film slice for TEM measurement, first, a thin film slice for TEM measurement can be cut out using a glass knife fixed to the main body of the ultramicrotome as shown in FIG. The tip of the resin casting was trimmed until it became a shape.
　より詳細には、図１２（ｂ）に示すように、樹脂注型物の先端の断面形状が、縦２００～４００μｍ及び横１００～２００μｍの長さを有する略直方体状となるようにトリミング加工した。断面の横の長さを１００～２００μｍとするのは、樹脂注型物からＴＥＭ測定用の薄膜切片を切り出す際に、ダイヤモンドナイフと試料との間で発生する摩擦を低減するためである。これにより、ＴＥＭ測定用の薄膜切片の皺及び折れ曲がりを防ぎ易くなり、ＴＥＭ測定用の薄膜切片の作製が容易となる。 More specifically, as shown in FIG. 12B, trimming was performed so that the cross-sectional shape of the tip of the resin casting was a substantially rectangular parallelepiped having a length of 200 to 400 μm and a width of 100 to 200 μm. . The reason why the horizontal length of the cross section is set to 100 to 200 μm is to reduce friction generated between the diamond knife and the sample when a thin film section for TEM measurement is cut out from a resin casting. This makes it easy to prevent wrinkling and bending of the thin film slice for TEM measurement, and facilitates production of the thin film slice for TEM measurement.
　続いて、ウルトラミクロトーム装置本体の所定の箇所に、ボート付きのダイヤモンドナイフ（ＤＩＡＴＯＮＥ社製、商品名「Ｃｒｙｏ　Ｗｅｔ」、刃幅２．０ｍｍ、刃角度３５°）を固定した。次に、ボートをイオン交換水で満たし、ナイフの設置角度を調整して刃先をイオン交換水で濡らした。 Subsequently, a diamond knife with a boat (manufactured by DIATONE, trade name “Cryo Wet”, blade width 2.0 mm, blade angle 35 °) was fixed to a predetermined position of the main body of the ultramicrotome device. Next, the boat was filled with ion-exchanged water, the knife installation angle was adjusted, and the cutting edge was wetted with ion-exchanged water.
　ここで、ナイフの設置角度の調整について図１３を用いて説明する。ナイフの設置角度の調整においては、上下方向の角度、左右方向の角度及びクリアランス角を調整することができる。「上下方向の角度の調整」とは、図１３に示すように、試料表面とナイフの進む方向とが平行になるように試料ホルダーの上下方向の角度を調整することを意味する。「左右方向の角度の調整」とは、図１３に示すように、ナイフの刃先と試料表面とが平行になるようにナイフの左右方向の角度を調整することを意味する。「クリアランス角の調整」とは、図１３に示すように、ナイフの刃先の試料側の面とナイフの進む方向とがなす最小の角度を調整することを意味する。クリアランス角は、５～１０°が好ましい。クリアランス角が前記範囲であると、ナイフの刃先と試料表面との摩擦を低減できると共に、試料から薄膜切片を切り出した後にナイフが試料表面を擦ることを防げる。 Here, adjustment of the installation angle of the knife will be described with reference to FIG. In adjusting the installation angle of the knife, the vertical angle, the horizontal angle, and the clearance angle can be adjusted. “Adjusting the vertical angle” means adjusting the vertical angle of the sample holder so that the surface of the sample and the direction in which the knife advances are parallel to each other, as shown in FIG. “Adjusting the angle in the left-right direction” means adjusting the angle in the left-right direction of the knife so that the blade edge of the knife and the sample surface are parallel, as shown in FIG. “Adjustment of clearance angle” means adjusting the minimum angle formed by the surface of the knife edge on the sample side and the direction in which the knife proceeds, as shown in FIG. The clearance angle is preferably 5 to 10 °. When the clearance angle is within the above range, friction between the knife edge and the sample surface can be reduced, and the knife can be prevented from rubbing the sample surface after the thin film slice is cut out from the sample.
　ウルトラミクロトーム装置本体に付している光学顕微鏡を確認しながら、試料とダイヤモンドナイフとの距離を近づけて、刃速度０．３ｍｍ／秒、薄膜の切り出し厚さが６０ｎｍ±２０ｎｍとなるようにミクロトーム装置の設定値を設定し、樹脂注型物から薄膜切片を切り出した。次に、イオン交換水の水面にＴＥＭ測定用の薄膜切片を浮かべた。水面に浮かべたＴＥＭ測定用の薄膜切片の上面から、ＴＥＭ測定用の銅メッシュ（マイクログリッド付き銅メッシュ）を押し付け、ＴＥＭ測定用の薄膜切片を銅メッシュに吸着させ、ＴＥＭ試料とした。ミクロトームで得られるＴＥＭ測定用の薄膜切片は、ミクロトームの切り出し厚さの設定値と正確には一致しないため、所望の厚さが得られる設定値を予め求めておく。 While confirming the optical microscope attached to the main body of the ultramicrotome apparatus, the distance between the sample and the diamond knife is made closer, the blade speed is 0.3 mm / second, and the thinning thickness of the thin film is 60 nm ± 20 nm. Was set, and a thin film slice was cut out from the resin casting. Next, a thin film slice for TEM measurement was floated on the surface of the ion exchange water. A copper mesh for TEM measurement (copper mesh with a microgrid) was pressed from the upper surface of the thin film slice for TEM measurement floated on the water surface, and the thin film slice for TEM measurement was adsorbed to the copper mesh to obtain a TEM sample. Since the thin film slice for TEM measurement obtained by the microtome does not exactly match the set value of the cut-out thickness of the microtome, a set value for obtaining a desired thickness is obtained in advance.
（ＥＤＸによるマッピングの方法）
　ＥＤＸによるマッピングの方法の詳細について説明する。ＴＥＭ測定用の薄膜切片を銅メッシュごと試料ホルダー（日本電子株式会社製、商品名「ベリリウム試料２軸傾斜ホルダー、ＥＭ－３１６４０」）に固定し、ＴＥＭ内部へ挿入した。加速電圧２００ｋＶにて、試料への電子線照射を開始した後、電子線の照射系をＳＴＥＭモードに切り替えた。 (Mapping method using EDX)
Details of the mapping method by EDX will be described. The thin film slice for TEM measurement was fixed together with a copper mesh to a sample holder (trade name “Beryllium sample biaxial tilt holder, EM-31640” manufactured by JEOL Ltd.) and inserted into the TEM. After irradiating the sample with an electron beam at an acceleration voltage of 200 kV, the electron beam irradiation system was switched to the STEM mode.
　走査像観察装置をＳＴＥＭ観察時の位置に挿入し、ＳＴＥＭ観察用のソフトウェア「ＪＥＯＬ　Ｓｉｍｐｌｅ　Ｉｍａｇｅ　Ｖｉｅｗｅｒ（Ｖｅｒｓｉｏｎ　１．３．５）」（日本電子株式会社製）を起動してから、ＴＥＭ測定用の薄膜切片を観察した。その中に観察された導電粒子の断面のうち、ＥＤＸ測定に適した箇所を探し、撮影した。ここでいう「測定に適した箇所」とは、導電粒子の中心付近で切断され、金属層の断面が観察できる箇所を意味する。断面が傾斜している箇所、及び、導電粒子の中心付近からずれた位置で切断されている箇所は、測定対象から外した。撮影時には、観察倍率２５万倍、ＳＴＥＭ観察像の画素数を縦５１２点、横５１２点とした。この条件で観察すると、視野角６００ｎｍの観察像が得られるが、装置が変わると同じ倍率でも視野角が変わることがあるため注意が必要である。 Insert the scanning image observation device into the STEM observation position, start the STEM observation software “JEOL Simple Image Viewer (Version 1.3.5)” (manufactured by JEOL Ltd.), and use it for TEM measurement. Thin film sections were observed. A portion suitable for EDX measurement was searched for and photographed in the cross section of the conductive particles observed therein. Here, “location suitable for measurement” means a location where the cross section of the metal layer can be observed by cutting near the center of the conductive particles. The part where the cross section is inclined and the part cut at a position shifted from the vicinity of the center of the conductive particles were excluded from the measurement target. At the time of photographing, the observation magnification was 250,000 times, and the number of pixels of the STEM observation image was 512 points vertically and 512 points horizontally. Observation under this condition gives an observation image with a viewing angle of 600 nm. However, care should be taken because the viewing angle may change even at the same magnification when the apparatus is changed.
　ＳＴＥＭ／ＥＤＸ分析の際には、ＴＥＭ測定用の薄膜切片に電子線を当てると、導電粒子の樹脂粒子及び注型樹脂には収縮及び熱膨張が起こり、測定中に試料が変形又は移動してしまう。このようなＥＤＸ測定中の試料変形及び試料移動を抑制するため、事前に３０分間～１時間程度、測定箇所に電子線を照射し、変形及び移動が収まったことを確認してから分析した。 In the STEM / EDX analysis, if an electron beam is applied to a thin film slice for TEM measurement, the resin particles of the conductive particles and the casting resin are contracted and thermally expanded, and the sample is deformed or moved during the measurement. End up. In order to suppress such deformation and movement of the sample during EDX measurement, the measurement site was irradiated with an electron beam for about 30 minutes to 1 hour in advance, and analysis was performed after confirming that the deformation and movement had subsided.
　ＳＴＥＭ／ＥＤＸ分析を行うため、ＥＤＸを測定位置まで移動させ、ＥＤＸ測定用のソフトウェア「Ａｎａｌｙｓｉｓ　Ｓｔａｔｉｏｎ」（日本電子株式会社製）を起動させた。ＥＤＸによるマッピングの際には、マッピング時に充分な分解能を得る必要があるため、電子線を目的箇所に集束させるための集束絞り装置を用いた。 In order to perform STEM / EDX analysis, EDX was moved to the measurement position, and EDX measurement software “Analysis Station” (manufactured by JEOL Ltd.) was started. When mapping by EDX, it is necessary to obtain a sufficient resolution at the time of mapping. Therefore, a focusing diaphragm device for focusing an electron beam at a target location is used.
　ＳＴＥＭ／ＥＤＸ分析の際には、検出される特性Ｘ線のカウント数（ＣＰＳ：Ｃｏｕｎｔｓ　Ｐｅｒ　Ｓｅｃｏｎｄ）が１０，０００ＣＰＳ以上になるように、電子線のスポット径を０．５～１．０ｎｍの範囲で調整した。測定後に、マッピング測定と同時に得られるＥＤＸスペクトルにおいて、ニッケルのＫα線に由来するピークの高さが少なくとも５，０００Ｃｏｕｎｔｓ以上となることを確認した。データ取得時には、前記ＳＴＥＭ観察時と同じ視野角で、画素数を縦２５６点、横２５６点とした。一点ごとの積算時間を２０ミリ秒間とし、積算回数１回で測定を行った。 In the case of STEM / EDX analysis, the electron beam spot diameter is in the range of 0.5 to 1.0 nm so that the number of detected characteristic X-rays (CPS: Counts Per Second) is 10,000 CPS or more. Adjusted. After the measurement, in the EDX spectrum obtained simultaneously with the mapping measurement, it was confirmed that the peak height derived from the Kα ray of nickel was at least 5,000 Counts or more. At the time of data acquisition, the number of pixels was 256 points in the vertical direction and 256 points in the horizontal direction with the same viewing angle as that in the STEM observation. The integration time for each point was 20 milliseconds, and the measurement was performed once.
　得られたＥＤＸマッピングデータから、必要に応じて、第１層、無電解ニッケルめっき析出核、第２層におけるＥＤＸスペクトルを抽出し、各部分における元素存在比を算出した。但し、定量値を算出する際には、貴金属、ニッケル及びリンの割合の合計を１００質量％として、それぞれの元素の質量％濃度を算出した。 From the obtained EDX mapping data, EDX spectra in the first layer, the electroless nickel plating precipitation nuclei, and the second layer were extracted as needed, and the element abundance ratio in each part was calculated. However, when calculating the quantitative value, the sum of the proportions of the noble metal, nickel and phosphorus was 100% by mass, and the mass% concentration of each element was calculated.
　前記以外の元素については、下記の理由で割合が変動し易いため、定量値を算出する際には除外した。炭素の割合は、ＴＥＭ測定用のメッシュに使用されるカーボン支持膜、又は、電子線照射時に試料表面に吸着する不純物の影響によって増減する。酸素の割合は、ＴＥＭ試料を作製してから測定までの間に空気酸化することで増加する可能性がある。銅は、ＴＥＭ測定用に用いた銅メッシュから検出されてしまう。 The elements other than the above were excluded when calculating the quantitative values because the ratios were likely to fluctuate for the following reasons. The ratio of carbon increases or decreases depending on the influence of impurities adsorbed on the surface of the sample when the carbon support film used in the mesh for TEM measurement or electron beam irradiation. The proportion of oxygen may be increased by air oxidation between the preparation of the TEM sample and the measurement. Copper will be detected from the copper mesh used for TEM measurement.
｛外径１μｍ以上の金属異物｝
　外径１μｍ以上の金属異物の個数の測定は、ＳＥＭにより５千倍で１０００個の導電粒子を観察し、１０００個の導電粒子を観察中に発見された外径１μｍ以上の金属異物の個数をカウントした。 {Metal foreign matter with outer diameter of 1μm or more}
Measurement of the number of metal foreign objects having an outer diameter of 1 μm or more is performed by observing 1000 conductive particles at a magnification of 5,000 by SEM, and the number of metal foreign objects having an outer diameter of 1 μm or more found during the observation of 1000 conductive particles. I counted.
｛異常析出部の有無｝
　長さ５００ｎｍを超える突起（異常析出部）の有無は、図１４に模式的に示す方法により判別した。具体的には、ＳＥＭにより３万倍で１０００個の導電粒子４００を観察し、異常析出部４０１の基端における直径方向の両端を結んだ直線（異常析出部４０１の両側の谷と谷とを結んだ直線）から垂直方向における異常析出部４０１の頂点までの距離を計測することにより、異常析出部４０１の長さ４０２を得た。そして、長さ５００ｎｍを超える異常析出部を有する導電粒子数をカウントした。 {Presence or absence of abnormal precipitation part}
Presence / absence of protrusions (abnormal precipitates) exceeding 500 nm in length was determined by the method schematically shown in FIG. Specifically, 1000 conductive particles 400 were observed by SEM at a magnification of 30,000, and a straight line connecting both ends in the diameter direction at the base end of the abnormal precipitation portion 401 (the valleys and valleys on both sides of the abnormal precipitation portion 401 were The length 402 of the abnormal precipitation portion 401 was obtained by measuring the distance from the connected straight line) to the apex of the abnormal precipitation portion 401 in the vertical direction. Then, the number of conductive particles having abnormal precipitation portions exceeding 500 nm in length was counted.
（単分散率の測定）
　導電粒子０．０５ｇを電解水に分散させ、界面活性剤を添加し、超音波分散（アズワン株式会社製、商品名「ＵＳ－４Ｒ」、高周波出力：１６０Ｗ、発振周波数：４０ｋＨｚ単周波）を５分間行った。導電粒子の分散液をＣＯＵＬＥＲ　ＭＵＬＴＩＳＩＺＥＲ　ＩＩ（ベックマン・コールター株式会社製、商品名）の試料カップに注入し、導電粒子５００００個についての単分散率を測定した。単分散率は下記式により算出し、その値に基づいて下記基準により水溶媒中での粒子の凝集性を判定した。
　単分散率（％）＝｛ｆｉｒｓｔ　ｐｅａｋ粒子数（個）／全粒子数（個）｝×１００ (Measurement of monodispersion)
0.05 g of conductive particles are dispersed in electrolyzed water, a surfactant is added, and ultrasonic dispersion (manufactured by ASONE, trade name “US-4R”, high frequency output: 160 W, oscillation frequency: 40 kHz single frequency) is 5 Went for a minute. The dispersion liquid of the conductive particles was poured into a sample cup of COULER MULTISIZER II (trade name, manufactured by Beckman Coulter, Inc.), and the monodispersion rate for 50000 conductive particles was measured. The monodispersion rate was calculated by the following formula, and based on the value, the cohesiveness of particles in an aqueous solvent was determined according to the following criteria.
Monodispersion rate (%) = {first peak number of particles (number) / total number of particles (number)} × 100
［絶縁性粒子の作製］
　５００ｍｌフラスコに入った純水４００ｇ中に、下に示す絶縁性粒子の配合モル比に従ってモノマーを加えた。全モノマーの総量が、純水に対して１０質量％になるように配合した。窒素置換後、７０℃で撹拌しながら６時間加熱を行った。攪拌速度は３００ｍｉｎ－１（３００ｒｐｍ）であった。ＫＢＭ－５０３（信越化学株式会社製、商品名）は、３－メタクリロキシプロピルトリメトキシシランである。 [Production of insulating particles]
A monomer was added to 400 g of pure water in a 500 ml flask according to the blending molar ratio of insulating particles shown below. It mix | blended so that the total amount of all the monomers might be 10 mass% with respect to pure water. After nitrogen substitution, heating was performed for 6 hours with stirring at 70 ° C. The stirring speed was 300 min −1 (300 rpm). KBM-503 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) is 3-methacryloxypropyltrimethoxysilane.
（絶縁性粒子の配合モル比）
成分　　　　　　　　　　　　　　　モル比
スチレン　　　　　　　　　　　　　６００
ペルオキソ二硫酸カリウム　　　　　６
メタクリル酸ナトリウム　　　　　　５．４
スチレンスルホン酸ナトリウム　　　０．３２
ジビニルベンゼン　　　　　　　　　１６．８
ＫＢＭ－５０３　　　　　　　　　　４．２ (Molar ratio of insulating particles)
Component Molar ratio Styrene 600
Potassium peroxodisulfate 6
Sodium methacrylate 5.4
Sodium styrenesulfonate 0.32
Divinylbenzene 16.8
KBM-503 4.2
　合成した絶縁性粒子の平均粒径をＳＥＭにより撮影した画像を解析して測定した。絶縁性粒子の平均粒径は３１５ｎｍであった。 The average particle size of the synthesized insulating particles was measured by analyzing an image taken by SEM. The average particle size of the insulating particles was 315 nm.
　合成した絶縁性粒子のＴｇ（ガラス転移点）を、ＤＳＣ（パーキンエルマー社製、商品名「ＤＳＣ－７」）を用いて、サンプル量：１０ｍｇ、昇温速度：５℃／分、測定雰囲気：空気の条件で測定した。 The Tg (glass transition point) of the synthesized insulating particles was measured using DSC (trade name “DSC-7”, manufactured by Perkin Elmer Co., Ltd.), sample amount: 10 mg, temperature increase rate: 5 ° C./min, measurement atmosphere: Measured under air conditions.
（シリコーンオリゴマーの調製）
　攪拌装置、コンデンサー及び温度計を備えたガラスフラスコに、３－グリシドキシプロピルトリメトキシシラン１１８ｇとメタノール５．９ｇとを配合した溶液を加えた。さらに、活性白土５ｇ及び蒸留水４．８ｇを添加し、７５℃で一定時間攪拌した後、重量平均分子量１３００のシリコーンオリゴマーを得た。得られたシリコーンオリゴマーは、水酸基と反応する末端官能基としてメトキシ基又はシラノール基を有するものである。得られたシリコーンオリゴマー溶液にメタノールを加えて、固形分２０質量％の処理液を調製した。 (Preparation of silicone oligomer)
A solution containing 118 g of 3-glycidoxypropyltrimethoxysilane and 5.9 g of methanol was added to a glass flask equipped with a stirrer, a condenser and a thermometer. Further, 5 g of activated clay and 4.8 g of distilled water were added and stirred at 75 ° C. for a certain time, and then a silicone oligomer having a weight average molecular weight of 1300 was obtained. The obtained silicone oligomer has a methoxy group or a silanol group as a terminal functional group that reacts with a hydroxyl group. Methanol was added to the obtained silicone oligomer solution to prepare a treatment liquid having a solid content of 20% by mass.
　シリコーンオリゴマーの重量平均分子量は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）法によって測定し、標準ポリスチレンの検量線を用いて換算することにより算出した。シリコーンオリゴマーの重量平均分子量の測定においては、ポンプ（株式会社日立製作所製、商品名「Ｌ－６０００」））と、カラム（Ｇｅｌｐａｃｋ　ＧＬ－Ｒ４２０、Ｇｅｌｐａｃｋ　ＧＬ－Ｒ４３０、Ｇｅｌｐａｃｋ　ＧＬ－Ｒ４４０（以上、日立化成株式会社製、商品名））と、　検出器（株式会社日立製作所製、商品名「Ｌ－３３００型ＲＩ」）とを用いた。溶離液としてテトラヒドロフラン（ＴＨＦ）を用い、測定温度を４０℃とし、流量を２．０５ｍＬ／分として測定した。 The weight average molecular weight of the silicone oligomer was measured by a gel permeation chromatography (GPC) method and calculated by using a standard polystyrene calibration curve. In the measurement of the weight average molecular weight of the silicone oligomer, a pump (manufactured by Hitachi, Ltd., trade name “L-6000”)) and a column (Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (or more, Hitachi, Ltd.) And a detector (manufactured by Hitachi, Ltd., trade name “L-3300 type RI”). Tetrahydrofuran (THF) was used as an eluent, the measurement temperature was 40 ° C., and the flow rate was 2.05 mL / min.
［絶縁被覆導電粒子の作製］
　メルカプト酢酸８ｍｍｏｌをメタノール２００ｍｌに溶解させて反応液を調製した。次に導電粒子（実施例１においては、粒子Ｄ）を２ｇ上記反応液に加え、スリーワンモーターと直径４５ｍｍの攪拌羽で、室温で２時間攪拌した。メタノールで洗浄後、孔径３μｍのメンブレンフィルタ（メルクミリポア社製）を用いてろ過することで、表面にカルボキシル基を有する導電粒子を２ｇ得た。 [Preparation of insulating coated conductive particles]
A reaction solution was prepared by dissolving 8 mmol of mercaptoacetic acid in 200 ml of methanol. Next, 2 g of conductive particles (particle D in Example 1) was added to the reaction solution, and the mixture was stirred at room temperature for 2 hours with a three-one motor and a stirring blade having a diameter of 45 mm. After washing with methanol, 2 g of conductive particles having a carboxyl group on the surface was obtained by filtering using a membrane filter (manufactured by Merck Millipore) having a pore size of 3 μm.
　次に重量平均分子量７０，０００の３０％ポリエチレンイミン水溶液（和光純薬工業株式会社製）を超純水で希釈し、０．３質量％ポリエチレンイミン水溶液を得た。上記表面にカルボキシル基を有する導電粒子２ｇを０．３質量％ポリエチレンイミン水溶液に加え、室温で１５分攪拌した。その後、孔径３μｍのメンブレンフィルタ（メルクミリポア社製）を用いて導電粒子をろ過し、ろ過された導電粒子を超純水２００ｇに入れて室温で５分攪拌した。更に孔径３μｍのメンブレンフィルタ（メルクミリポア社製）を用いて導電粒子をろ過し、上記メンブレンフィルタ上にて２００ｇの超純水で２回洗浄を行った。これらの作業を行うことにより、吸着していないポリエチレンイミンが除去され、表面がアミノ基含有ポリマーで被覆された導電粒子が得られた。 Next, a 30% polyethyleneimine aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) having a weight average molecular weight of 70,000 was diluted with ultrapure water to obtain a 0.3 mass% polyethyleneimine aqueous solution. 2 g of the conductive particles having a carboxyl group on the surface were added to a 0.3% by mass polyethyleneimine aqueous solution and stirred at room temperature for 15 minutes. Thereafter, the conductive particles were filtered using a membrane filter (manufactured by Merck Millipore) having a pore size of 3 μm, and the filtered conductive particles were put in 200 g of ultrapure water and stirred at room temperature for 5 minutes. Furthermore, the conductive particles were filtered using a membrane filter (manufactured by Merck Millipore) having a pore size of 3 μm, and washed twice with 200 g of ultrapure water on the membrane filter. By performing these operations, unimsorbed polyethyleneimine was removed, and conductive particles whose surface was coated with an amino group-containing polymer were obtained.
　次に、絶縁性粒子をシリコーンオリゴマーで処理し、表面にグリシジル基含有オリゴマーを有する絶縁性粒子のメタノール分散媒（絶縁性粒子のメタノール分散媒）を調製した。 Next, the insulating particles were treated with a silicone oligomer to prepare a methanol dispersion medium of insulating particles having a glycidyl group-containing oligomer on the surface (a methanol dispersion medium of insulating particles).
　上記表面がアミノ基含有ポリマーで被覆された導電粒子をメタノールに浸漬し、当該メタノールに絶縁性粒子のメタノール分散媒を滴下することで、絶縁被覆導電粒子を作製した。得られた絶縁被覆導電粒子を縮合剤とオクタデシルアミンで処理し、洗浄して表面の疎水化を行った。その後８０℃、１時間の条件で加熱乾燥させて絶縁被覆導電粒子を作製した。ＳＥＭによって撮影した画像を解析することで、絶縁性粒子による導電粒子の平均被覆率を測定したところ、約３０％であった。 The conductive particles whose surface was coated with an amino group-containing polymer were immersed in methanol, and a methanol dispersion medium of insulating particles was dropped into the methanol to produce insulating coated conductive particles. The obtained insulating coated conductive particles were treated with a condensing agent and octadecylamine and washed to make the surface hydrophobic. Thereafter, the film was heat-dried at 80 ° C. for 1 hour to produce insulating coated conductive particles. When the average coverage of the conductive particles by the insulating particles was measured by analyzing an image taken by SEM, it was about 30%.
［異方導電性接着フィルム及び接続構造体の作製］
　フェノキシ樹脂（ユニオンカーバイド社製、商品名「ＰＫＨＣ」）１００ｇと、アクリルゴム（ブチルアクリレート４０質量部、エチルアクリレート３０質量部、アクリロニトリル３０質量部、グリシジルメタクリレート３質量部の共重合体、分子量：８５万）７５ｇとを、酢酸エチル４００ｇに溶解して溶液を得た。この溶液に、マイクロカプセル型潜在性硬化剤を含有する液状エポキシ樹脂（旭化成エポキシ株式会社製、商品名「ノバキュアＨＸ－３９４１」、エポキシ当量１８５）３００ｇを加え、撹拌して接着剤溶液を得た。 [Preparation of anisotropic conductive adhesive film and connection structure]
Copolymer of 100 g of phenoxy resin (trade name “PKHC” manufactured by Union Carbide) and acrylic rubber (40 parts by mass of butyl acrylate, 30 parts by mass of ethyl acrylate, 30 parts by mass of acrylonitrile, 3 parts by mass of glycidyl methacrylate, molecular weight: 85 Ten thousand) was dissolved in 400 g of ethyl acetate to obtain a solution. To this solution, 300 g of a liquid epoxy resin containing a microcapsule type latent curing agent (trade name “Novacure HX-3941”, epoxy equivalent 185, manufactured by Asahi Kasei Epoxy Co., Ltd.) was added and stirred to obtain an adhesive solution. .
　この接着剤溶液に、上記絶縁被覆導電粒子を、接着剤溶液の全量を基準として９体積％となるように分散させ、分散液を得た。得られた分散液を、セパレータ（シリコーン処理したポリエチレンテレフタレートフィルム、厚さ４０μｍ）にロールコータを用いて塗布し、９０℃で１０分間加熱することにより乾燥して、厚さ２５μｍの異方導電性接着フィルムをセパレータ上に作製した。 In the adhesive solution, the insulating coated conductive particles were dispersed so as to be 9% by volume based on the total amount of the adhesive solution, thereby obtaining a dispersion. The obtained dispersion is applied to a separator (silicone-treated polyethylene terephthalate film, thickness 40 μm) using a roll coater, dried by heating at 90 ° C. for 10 minutes, and has an anisotropic conductivity of 25 μm in thickness. An adhesive film was produced on the separator.
　次に、作製した異方導電性接着フィルムを用いて、金バンプ（１）（面積：約２０μｍ×約４０μｍ、高さ：１５μｍ）、金バンプ（２）（面積：約３０μｍ×約４０μｍ、高さ：１５μｍ）、及び金バンプ（３）（面積：約４０μｍ×約４０μｍ、高さ：１５μｍ）がそれぞれ３６２個設けられたチップ（１．７ｍｍ×２０ｍｍ、厚さ：０．５μｍ）と、ＩＺＯ回路付きガラス基板（厚さ：０．７ｍｍ）との接続を、以下に示すｉ）～ｉｉｉ）の手順に従って行い、接続構造体を得た。金バンプ（１）のスペースを６μｍとし、金バンプ（２）のスペースを８μｍとし、金バンプ（３）のスペースを１０μｍとした。スペースとは、金バンプ同士の距離に相当する。
　ｉ）異方導電性接着フィルム（２ｍｍ×２４ｍｍ）をＩＺＯ回路付きガラス基板に８０℃、０．９８ＭＰａ（１０ｋｇｆ／ｃｍ２）で貼り付けた。
　ｉｉ）セパレータを剥離し、チップのバンプとＩＺＯ回路付きガラス基板の位置合わせを行った。
　ｉｉｉ）１９０℃、４０ｇｆ／バンプ、１０秒の条件でチップ上方から加熱及び加圧を行い、チップとガラス基板との接着を行うと共に、チップのバンプとＩＺＯ回路との電気的接続を行った。 Next, using the produced anisotropic conductive adhesive film, gold bump (1) (area: about 20 μm × about 40 μm, height: 15 μm), gold bump (2) (area: about 30 μm × about 40 μm, high And a chip (1.7 mm × 20 mm, thickness: 0.5 μm) each provided with 362 gold bumps (3) (area: about 40 μm × about 40 μm, height: 15 μm), and IZO Connection with a glass substrate with a circuit (thickness: 0.7 mm) was performed according to the following procedures i) to iii) to obtain a connection structure. The space of the gold bump (1) was 6 μm, the space of the gold bump (2) was 8 μm, and the space of the gold bump (3) was 10 μm. A space corresponds to the distance between gold bumps.
i) An anisotropic conductive adhesive film (2 mm × 24 mm) was attached to a glass substrate with an IZO circuit at 80 ° C. and 0.98 MPa (10 kgf / cm 2 ).
ii) The separator was peeled off, and the bumps of the chip and the glass substrate with IZO circuit were aligned.
iii) Heating and pressing were performed from above the chip under the conditions of 190 ° C., 40 gf / bump, and 10 seconds to bond the chip and the glass substrate, and to electrically connect the chip bump and the IZO circuit.
［接続構造体の評価］
　得られた接続構造体の導通抵抗試験及び絶縁抵抗試験を以下のように行った。 [Evaluation of connection structure]
The conduction resistance test and the insulation resistance test of the obtained connection structure were performed as follows.
（導通抵抗試験）
　チップ電極（バンプ）とＩＺＯ回路との接続において、導通抵抗の初期値と、吸湿耐熱試験（温度８５℃、湿度８５％の条件で１００、３００、５００、１０００、２０００時間放置）後の導通抵抗の値とを測定した。チップ電極（バンプ）とＩＺＯ回路との接続領域は、約２０μｍ×約４０μｍ、約３０μｍ×約４０μｍ、及び約４０μｍ×約４０μｍとした。約２０μｍ×約４０μｍの接続領域においては、チップ電極とＩＺＯ回路とは３個の導電粒子（捕捉導電粒子）で接続されるように設定した。約３０μｍ×約４０μｍの接続領域においては、チップ電極とＩＺＯ回路とは６個の導電粒子で接続されるように設定した。約４０μｍ×約４０μｍの接続領域においては、チップ電極とＩＺＯ回路とは１０個の導電粒子で接続されるように設定した。なお、２０サンプルについて測定し、それらの平均値を算出した。得られた平均値から下記基準に従って導通抵抗を評価した結果を表６－１に示す。バンプ数６個において、吸湿耐熱試験５００時間後に下記Ａ又はＢの基準を満たす場合、導通抵抗が良好であると評価した。
　　Ａ：導通抵抗の平均値が２Ω未満
　　Ｂ：導通抵抗の平均値が２Ω以上５Ω未満
　　Ｃ：導通抵抗の平均値が５Ω以上１０Ω未満
　　Ｄ：導通抵抗の平均値が１０Ω以上２０Ω未満
　　Ｅ：導通抵抗の平均値が２０Ω以上 (Conduction resistance test)
In the connection between the chip electrode (bump) and the IZO circuit, the initial value of the conduction resistance and the conduction resistance after the moisture absorption heat resistance test (left at 100, 300, 500, 1000, 2000 hours under conditions of a temperature of 85 ° C. and a humidity of 85%) The value of was measured. The connection region between the chip electrode (bump) and the IZO circuit was about 20 μm × about 40 μm, about 30 μm × about 40 μm, and about 40 μm × about 40 μm. In the connection region of about 20 μm × about 40 μm, the chip electrode and the IZO circuit were set to be connected by three conductive particles (trapping conductive particles). In the connection area of about 30 μm × about 40 μm, the chip electrode and the IZO circuit were set to be connected by six conductive particles. In the connection area of about 40 μm × about 40 μm, the chip electrode and the IZO circuit were set to be connected by 10 conductive particles. In addition, it measured about 20 samples and computed those average values. The results of evaluating the conduction resistance from the average value obtained according to the following criteria are shown in Table 6-1. When the number of bumps was 6, and the following A or B criteria were satisfied after 500 hours of the moisture absorption heat test, it was evaluated that the conduction resistance was good.
A: Average value of conduction resistance is less than 2Ω B: Average value of conduction resistance is 2Ω or more and less than 5Ω C: Average value of conduction resistance is 5Ω or more and less than 10Ω D: Average value of conduction resistance is 10Ω or more and less than 20Ω E: Conduction resistance The average value of 20Ω or more
（絶縁抵抗試験）
　チップ電極（バンプ）間の絶縁抵抗として、絶縁抵抗の初期値と、マイグレーション試験（温度６０℃、湿度９０％、２０Ｖ印加の条件で１００、３００、１０００、２０００時間放置）後の絶縁抵抗の値とを測定した。２０サンプルについて測定し、全２０サンプル中、絶縁抵抗値が１０９Ω以上となるサンプルの割合を算出した。測定は、金バンプ（１）～（３）のそれぞれについて行った。すなわち、金バンプのスペースが６μｍ、８μｍ、１０μｍのそれぞれについて、絶縁抵抗試験を行った。得られた割合から下記基準に従って絶縁抵抗を評価した。結果を表６－１に示す。スペースが８μｍにおいて、吸湿耐熱試験１０００時間後に下記Ａ又はＢの基準を満たす場合、絶縁抵抗が良好であると評価した。
　　Ａ：絶縁抵抗値１０９Ω以上の割合が１００％
　　Ｂ：絶縁抵抗値１０９Ω以上の割合が９０％以上１００％未満
　　Ｃ：絶縁抵抗値１０９Ω以上の割合が８０％以上９０％未満
　　Ｄ：絶縁抵抗値１０９Ω以上の割合が５０％以上８０％未満
　　Ｅ：絶縁抵抗値１０９Ω以上の割合が５０％未満 (Insulation resistance test)
As the insulation resistance between the chip electrodes (bumps), the initial value of the insulation resistance and the value of the insulation resistance after migration test (temperature, 60 ° C., humidity 90%, 20 V application for 100, 300, 1000, 2000 hours) And measured. Measurement was performed on 20 samples, and the ratio of samples having an insulation resistance value of 10 9 Ω or more was calculated among all 20 samples. The measurement was performed for each of the gold bumps (1) to (3). That is, the insulation resistance test was performed for each of the gold bump spaces of 6 μm, 8 μm, and 10 μm. The insulation resistance was evaluated from the obtained ratio according to the following criteria. The results are shown in Table 6-1. When the space satisfies the following criteria A or B after 1000 hours in the moisture absorption heat test at 8 μm, the insulation resistance was evaluated as good.
A: Ratio of insulation resistance value of 10 9 Ω or more is 100%
B: Ratio of insulation resistance value 10 9 Ω or more is 90% or more and less than 100% C: Ratio of insulation resistance value 10 9 Ω or more is 80% or more and less than 90% D: Ratio of insulation resistance value 10 9 Ω or more is 50% More than 80% E: Insulation resistance of 10 9 Ω or more is less than 50%
＜実施例２＞
　実施例１の（工程ｂ）において、平均粒径６０ｎｍの気相法親水性球状シリカ粉末を、平均粒径２５ｎｍの気相法親水性球状シリカ粉末に変更したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表１－１、表１－２及び表６－１に示す。 <Example 2>
In the same manner as in Example 1 except that the gas phase method hydrophilic spherical silica powder having an average particle size of 60 nm was changed to the gas phase method hydrophilic spherical silica powder having an average particle size of 25 nm in (Step b) of Example 1. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-1, Table 1-2, and Table 6-1.
＜実施例３＞
　実施例１の（工程ｂ）において、平均粒径６０ｎｍの気相法親水性球状シリカ粉末を、平均粒径４０ｎｍの気相法親水性球状シリカ粉末に変更したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表１－１、表１－２及び表６－１に示す。 <Example 3>
In the same manner as in Example 1 except that the vapor-phase hydrophilic spherical silica powder having an average particle size of 60 nm was changed to a vapor-phase hydrophilic spherical silica powder having an average particle size of 40 nm in (Step b) of Example 1. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-1, Table 1-2, and Table 6-1.
＜実施例４＞
　実施例１の（工程ｂ）において、平均粒径６０ｎｍの気相法親水性球状シリカ粉末を、平均粒径８０ｎｍの気相法親水性球状シリカ粉末に変更したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表１－１、表１－２及び表６－１に示す。 <Example 4>
In the same manner as in Example 1 except that the gas phase method hydrophilic spherical silica powder having an average particle size of 60 nm was changed to the gas phase method hydrophilic spherical silica powder having an average particle size of 80 nm in (Step b) of Example 1. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-1, Table 1-2, and Table 6-1.
＜実施例５＞
　実施例１の（工程ｂ）において、平均粒径６０ｎｍの気相法親水性球状シリカ粉末を、平均粒径１００ｎｍの気相法親水性球状シリカ粉末に変更したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表１－３、表１－４及び表６－１に示す。 <Example 5>
In the same manner as in Example 1 except that the gas phase method hydrophilic spherical silica powder having an average particle size of 60 nm was changed to the gas phase method hydrophilic spherical silica powder having an average particle size of 100 nm in (Step b) of Example 1. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-3, Table 1-4, and Table 6-1.
＜実施例６＞
　実施例１の（工程ｂ）において、平均粒径６０ｎｍの気相法親水性球状シリカ粉末を、平均粒径１２０ｎｍの気相法親水性球状シリカ粉末に変更したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表１－３、表１－４及び表６－２に示す。 <Example 6>
In the same manner as in Example 1 except that the gas phase method hydrophilic spherical silica powder having an average particle size of 60 nm was changed to the gas phase method hydrophilic spherical silica powder having an average particle size of 120 nm in (Step b) of Example 1. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 1-3, Table 1-4, and Table 6-2.
＜実施例７＞
　実施例１の（工程ｄ）において、パラジウム触媒化液として、ｐＨ１０．５に調整され、パラジウム触媒（アトテックジャパン株式会社製、商品名「アトテックネオガント８３４」）を８質量％含有するパラジウム触媒化液１００ｍＬを用いたこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表１－３、表１－４及び表６－２に示す。 <Example 7>
In (step d) of Example 1, as a palladium catalyst solution, adjusted to pH 10.5 and containing 8% by mass of a palladium catalyst (manufactured by Atotech Japan Co., Ltd., trade name “Atotech Neogant 834”) Except having used 100 mL of liquids, it carried out similarly to Example 1, and produced the electroconductive particle, the insulation coating electroconductive particle, the anisotropically conductive adhesive film, and the connection structure, and evaluated the electroconductive particle and the connection structure. . The results are shown in Table 1-3, Table 1-4, and Table 6-2.
＜実施例８＞
　実施例１の（工程ｂ）において、シリカ粉末として、平均粒径２５ｎｍの気相法親水性球状シリカ粉末を用いたこと、及び実施例１の（工程ｄ）において、パラジウム触媒化液として、ｐＨ１０．５に調整され、アトテックネオガント８３４を８質量％含有するパラジウム触媒化液１００ｍＬを用いたこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表２－１、表２－２及び表６－２に示す。 <Example 8>
In (Step b) of Example 1, gas phase method hydrophilic spherical silica powder having an average particle size of 25 nm was used as the silica powder, and in (Step d) of Example 1, pH 10 was used as the palladium catalyzed liquid. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film, and the same as in Example 1 except that 100 mL of a palladium-catalyzed solution containing 8 mass% of Atotech Neogant 834 was used. The connection structure was produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-1, Table 2-2 and Table 6-2.
＜実施例９＞
　実施例１の（工程ｂ）において、シリカ粉末として、平均粒径４０ｎｍの気相法親水性球状シリカ粉末を用いた点、及び実施例１の（工程ｄ）において、パラジウム触媒化液１００ｍＬの代わりに、ｐＨ１０．５に調整され、アトテックネオガント８３４を８質量％含有するパラジウム触媒化液１００ｍＬを用いたこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表２－１、表２－２及び表６－２に示す。 <Example 9>
In Example 1 (step b), a vapor phase hydrophilic spherical silica powder having an average particle size of 40 nm was used as the silica powder, and in Example 1 (step d), instead of 100 mL of the palladium-catalyzed solution. In addition, conductive particles, insulating coated conductive particles, anisotropic conductivity were obtained in the same manner as in Example 1 except that 100 mL of a palladium-catalyzed solution containing 8% by mass of Atotech Neogant 834 was adjusted to pH 10.5. The production of the adhesive film and the connection structure, and the evaluation of the conductive particles and the connection structure were performed. The results are shown in Table 2-1, Table 2-2 and Table 6-2.
＜実施例１０＞
　実施例１の（工程ｂ）において、シリカ粉末として、平均粒径８０ｎｍの気相法親水性球状シリカ粉末を用いたこと、及び実施例１の（工程ｄ）において、パラジウム触媒化液として、ｐＨ１０．５に調整され、アトテックネオガント８３４を８質量％含有するパラジウム触媒化液１００ｍＬを用いたこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表２－１、表２－２及び表７－１に示す。 <Example 10>
In (Step b) of Example 1, a vapor-phase hydrophilic spherical silica powder having an average particle size of 80 nm was used as the silica powder, and in Example 1 (Step d), a pH of 10 was used as the palladium-catalyzed liquid. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film, and the same as in Example 1 except that 100 mL of a palladium-catalyzed solution containing 8 mass% of Atotech Neogant 834 was used. The connection structure was produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-1, Table 2-2 and Table 7-1.
＜実施例１１＞
　実施例１の（工程ｂ）において、シリカ粉末として、平均粒径１００ｎｍの気相法親水性球状シリカ粉末を用いたこと、及び実施例１の（工程ｄ）において、パラジウム触媒化液として、ｐＨ１０．５に調整され、アトテックネオガント８３４を８質量％含有するパラジウム触媒化液１００ｍＬを用いたこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表２－１、表２－２及び表７－１に示す。 <Example 11>
In (Step b) of Example 1, gas phase method hydrophilic spherical silica powder having an average particle diameter of 100 nm was used as the silica powder, and in (Step d) of Example 1, pH 10 was used as the palladium-catalyzed liquid. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film, and the same as in Example 1 except that 100 mL of a palladium-catalyzed solution containing 8 mass% of Atotech Neogant 834 was used. The connection structure was produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-1, Table 2-2 and Table 7-1.
＜実施例１２＞
　実施例１の（工程ｂ）において、シリカ粉末として、平均粒径１２０ｎｍの気相法親水性球状シリカ粉末を用いたこと、及び実施例１の（工程ｄ）において、パラジウム触媒化液として、ｐＨ１０．５に調整され、アトテックネオガント８３４を８質量％含有するパラジウム触媒化液１００ｍＬを用いたこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表２－３、表２－４及び表７－１に示す。 <Example 12>
In (Step b) of Example 1, gas phase method hydrophilic spherical silica powder having an average particle size of 120 nm was used as the silica powder, and in (Step d) of Example 1, pH 10 was used as the palladium catalyzed liquid. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film, and the same as in Example 1 except that 100 mL of a palladium-catalyzed solution containing 8 mass% of Atotech Neogant 834 was used. The connection structure was produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-3, Table 2-4, and Table 7-1.
＜実施例１３＞
　実施例１の（工程ｂ）の代わりに、以下に示す方法にて非導電性無機粒子を製造した以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表２－３、表２－４及び表７－１に示す。 <Example 13>
Instead of (Step b) of Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film were produced in the same manner as Example 1 except that non-conductive inorganic particles were produced by the method shown below. The connection structure was manufactured, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-3, Table 2-4, and Table 7-1.
　実施例１３では、まず平均粒径１００ｎｍの気相法親水性球状シリカ粉末を用い、球状シリカ粉末１００ｇを振動流動層装置（中央化工機株式会社製、商品名「振動流動層装置ＶＵＡ－１５型」）に収容した。次に、循環ガスを用いずに、装置上部を開放した状態でコンプレッサーによる圧縮空気によって球状シリカを流動化させ、水３．０ｇを噴霧して５分間流動混合させた。次に、ＨＭＤＳ（ヘキサメチレンジシラザン）（モメンティブ・パフォーマンス・マテリアルズ・ジャパン合同会社製、商品名「ＴＳＬ－８８０２」）５．０ｇを噴霧し、３０分間流動混合した。得られた疎水性球状シリカ微粉体の疎水化度をメタノール滴定法によって測定した。実施例１３における非導電性無機粒子の疎水化度は、３０％であった。 In Example 13, first, a vapor phase hydrophilic spherical silica powder having an average particle diameter of 100 nm was used, and 100 g of the spherical silica powder was vibrated with a vibrating fluidized bed apparatus (trade name “vibrating fluidized bed apparatus VUA-15 type, manufactured by Chuo Kako Co., Ltd.). )). Next, without using the circulating gas, spherical silica was fluidized with compressed air by a compressor with the upper part of the apparatus being opened, and 3.0 g of water was sprayed and fluidized and mixed for 5 minutes. Next, 5.0 g of HMDS (hexamethylene disilazane) (product name “TSL-8802” manufactured by Momentive Performance Materials Japan GK) was sprayed and mixed by fluidization for 30 minutes. The hydrophobicity of the obtained hydrophobic spherical silica fine powder was measured by methanol titration method. The hydrophobicity of the non-conductive inorganic particles in Example 13 was 30%.
＜実施例１４＞
　実施例１の（工程ｂ）の代わりに、以下に示す方法にて非導電性無機粒子を製造した以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表２－３、表２－４及び表７－１に示す。 <Example 14>
Instead of (Step b) of Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film were produced in the same manner as Example 1 except that non-conductive inorganic particles were produced by the method shown below. The connection structure was manufactured, and the conductive particles and the connection structure were evaluated. The results are shown in Table 2-3, Table 2-4, and Table 7-1.
　実施例１４では、まず、平均粒径１００ｎｍの気相法親水性球状シリカ粉末を用い、球状シリカ粉末１００ｇを振動流動層装置（中央化工機株式会社製、商品名「振動流動層装置ＶＵＡ－１５型」）に収容した。次に、吸引ブロワーにより循環させた空気で球状シリカを流動化させながら水３．５ｇを噴霧し、５分間流動混合させた。次に、ＨＭＤＳ（ヘキサメチレンジシラザン）（モメンティブ・パフォーマンス・マテリアルズ・ジャパン合同会社製、商品名「ＴＳＬ－８８０２」）２．５ｇを噴霧し、３０分間流動混合した。得られた疎水性球状シリカ微粉体の疎水化度をメタノール滴定法によって測定した。実施例１３における非導電性無機粒子の疎水化度は、５０％であった。 In Example 14, first, vapor phase hydrophilic spherical silica powder having an average particle diameter of 100 nm was used, and 100 g of spherical silica powder was mixed with a vibrating fluidized bed apparatus (trade name “Vibrated Fluidized Bed Apparatus VUA-15, manufactured by Chuo Kako Co., Ltd.). Type "). Next, 3.5 g of water was sprayed while fluidizing the spherical silica with air circulated by a suction blower and fluidized and mixed for 5 minutes. Next, 2.5 g of HMDS (hexamethylene disilazane) (product name “TSL-8802” manufactured by Momentive Performance Materials Japan GK) was sprayed and mixed by fluidization for 30 minutes. The hydrophobicity of the obtained hydrophobic spherical silica fine powder was measured by methanol titration method. The hydrophobicity of the non-conductive inorganic particles in Example 13 was 50%.
＜実施例１５＞
　実施例１の（工程ｂ）の代わりに、以下に示す方法にて非導電性無機粒子を製造した以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表３－１、表３－２及び表７－２に示す。 <Example 15>
Instead of (Step b) of Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film were produced in the same manner as Example 1 except that non-conductive inorganic particles were produced by the method shown below. The connection structure was manufactured, and the conductive particles and the connection structure were evaluated. The results are shown in Table 3-1, Table 3-2 and Table 7-2.
　実施例１５では、まず、平均粒径１００ｎｍの気相法親水性球状シリカ粉末を用い、球状シリカ粉末１００ｇを振動流動層装置（中央化工機株式会社製、商品名「振動流動層装置ＶＵＡ－１５型」）に収容した。次に、吸引ブロワーにより循環させた空気で球状シリカを流動化させながら水３．０ｇを噴霧し、５分間流動混合させた。次に、ＨＭＤＳ（ヘキサメチレンジシラザン）（モメンティブ・パフォーマンス・マテリアルズ・ジャパン合同会社製、商品名「ＴＳＬ－８８０２」）５．０ｇを噴霧し、３０分間流動混合した。得られた疎水性球状シリカ微粉体の疎水化度をメタノール滴定法によって測定した。実施例１３における非導電性無機粒子の疎水化度は、８０％であった。 In Example 15, first, vapor phase hydrophilic spherical silica powder having an average particle diameter of 100 nm was used, and 100 g of spherical silica powder was mixed with a vibrating fluidized bed apparatus (trade name “Vibrated Fluidized Bed Apparatus VUA-15, manufactured by Chuo Kako Co., Ltd.). Type "). Next, 3.0 g of water was sprayed while fluidizing the spherical silica with air circulated by a suction blower and fluidized and mixed for 5 minutes. Next, 5.0 g of HMDS (hexamethylene disilazane) (product name “TSL-8802” manufactured by Momentive Performance Materials Japan GK) was sprayed and mixed by fluidization for 30 minutes. The hydrophobicity of the obtained hydrophobic spherical silica fine powder was measured by methanol titration method. The hydrophobicity of the nonconductive inorganic particles in Example 13 was 80%.
＜実施例１６＞
　実施例１の（工程ｂ）の代わりに、以下に示す方法にて非導電性無機粒子を製造した以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表３－１、表３－２及び表７－２に示す。 <Example 16>
Instead of (Step b) of Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film were produced in the same manner as Example 1 except that non-conductive inorganic particles were produced by the method shown below. The connection structure was manufactured, and the conductive particles and the connection structure were evaluated. The results are shown in Table 3-1, Table 3-2 and Table 7-2.
　実施例１６では、まず、平均粒径１００ｎｍの気相法親水性球状シリカ粉末を用い、球状シリカ粉末１００ｇを振動流動層装置（中央化工機株式会社製、商品名「振動流動層装置ＶＵＡ－１５型」）に収容した。次に、吸引ブロワーにより循環させた空気で球状シリカを流動化させながら水３．０ｇを噴霧し、５分間流動混合させた。次に、ＨＭＤＳ（ヘキサメチレンジシラザン）（モメンティブ・パフォーマンス・マテリアルズ・ジャパン合同会社製、商品名「ＴＳＬ－８８０２」）６．０ｇを噴霧し、３０分間流動混合した。得られた疎水性球状シリカ微粉体の疎水化度をメタノール滴定法によって測定した。実施例１３における非導電性無機粒子の疎水化度は、９０％であった。 In Example 16, first, vapor phase hydrophilic spherical silica powder having an average particle diameter of 100 nm was used, and 100 g of spherical silica powder was mixed with a vibrating fluidized bed apparatus (trade name “Vibrated Fluidized Bed Apparatus VUA-15, manufactured by Chuo Kako Co., Ltd.). Type "). Next, 3.0 g of water was sprayed while fluidizing the spherical silica with air circulated by a suction blower and fluidized and mixed for 5 minutes. Next, 6.0 g of HMDS (hexamethylene disilazane) (manufactured by Momentive Performance Materials Japan LLC, trade name “TSL-8802”) was sprayed and fluidly mixed for 30 minutes. The hydrophobicity of the obtained hydrophobic spherical silica fine powder was measured by methanol titration method. The hydrophobicity of the nonconductive inorganic particles in Example 13 was 90%.
＜実施例１７＞
　実施例１の（工程ｃ）において、ＨＭＤＳにより疎水化された球状シリカ粉末０．０５ｇの代わりに、０．０４ｇとしたこと以外は、実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表３－１、表３－２及び表７－２に示す。 <Example 17>
Conductive particles and insulating coated conductive particles in the same manner as in Example 1 except that 0.04 g was used instead of 0.05 g of the spherical silica powder hydrophobized by HMDS in (Step c) of Example 1. The production of anisotropic conductive adhesive films and connection structures, and the evaluation of conductive particles and connection structures were performed. The results are shown in Table 3-1, Table 3-2 and Table 7-2.
＜実施例１８＞
　実施例１の（工程ｃ）において、ＨＭＤＳにより疎水化された球状シリカ粉末０．０５ｇの代わりに、０．０３ｇとしたこと以外は、実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表３－１、表３－２及び表７－２に示す。 <Example 18>
Conductive particles and insulating coated conductive particles in the same manner as in Example 1 except that 0.03 g was used instead of 0.05 g of the spherical silica powder hydrophobized by HMDS in (Step c) of Example 1. The production of anisotropic conductive adhesive films and connection structures, and the evaluation of conductive particles and connection structures were performed. The results are shown in Table 3-1, Table 3-2 and Table 7-2.
＜実施例１９＞
　実施例１の（工程ａ）において、ポリエチレンイミン水溶液３ｇの代わりに、平均分子量６００の３０質量％ポリエチレンイミン水溶液（和光純薬工業株式会社製）３ｇに変更したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表３－３、表３－４及び表８－１に示す。 <Example 19>
In the same manner as in Example 1 except that 3 g of 30% by weight polyethyleneimine aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) having an average molecular weight of 600 was used instead of 3 g of the polyethyleneimine aqueous solution in (Step a) of Example 1. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 3-3, Table 3-4 and Table 8-1.
＜実施例２０＞
　実施例１の（工程ａ）において、ポリエチレンイミン水溶液３ｇの代わりに、平均分子量１万の３０質量％ポリエチレンイミン水溶液（和光純薬工業株式会社製）３ｇに変更したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表３－３、表３－４及び表８－１に示す。 <Example 20>
Example 1 (Step a) is the same as Example 1 except that in place of 3 g of the polyethyleneimine aqueous solution, 3 g of a 30% by weight polyethyleneimine aqueous solution having an average molecular weight of 10,000 (manufactured by Wako Pure Chemical Industries, Ltd.) Then, production of conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film and connection structure, and evaluation of conductive particles and connection structure were performed. The results are shown in Table 3-3, Table 3-4 and Table 8-1.
＜実施例２１＞
　実施例１の（工程ｂ）において、ＨＭＤＳ２．５ｇの代わりに、ポリジメチルシロキサン（ＰＤＭＳ）（和光純薬工業株式会社製）２．５ｇに変更したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表３－３、表３－４及び表８－１に示す。 <Example 21>
In the same manner as in Example 1 except that the polydimethylsiloxane (PDMS) (manufactured by Wako Pure Chemical Industries, Ltd.) 2.5 g was used instead of HMDS 2.5 g in (Step b) of Example 1, Production of particles, insulating coated conductive particles, anisotropic conductive adhesive film and connection structure, and evaluation of conductive particles and connection structure were performed. The results are shown in Table 3-3, Table 3-4 and Table 8-1.
＜実施例２２＞
　実施例１の（工程ｂ）において、ＨＭＤＳ２．５ｇの代わりに、Ｎ，Ｎ－ジメチルアミノトリメチルシラン（ＤＭＡＴＭＳ）（和光純薬工業株式会社製）２．５ｇに変更したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表４－１、表４－２及び表８－１に示す。 <Example 22>
Example 1 is different from Example 1 (step b) except that 2.5 g of N, N-dimethylaminotrimethylsilane (DMATMS) (manufactured by Wako Pure Chemical Industries, Ltd.) is used instead of 2.5 g of HMDS. Similarly, production of conductive particles, insulating coated conductive particles, anisotropic conductive adhesive film and connection structure, and evaluation of conductive particles and connection structure were performed. The results are shown in Table 4-1, Table 4-2, and Table 8-1.
＜実施例２３＞
　実施例１の（工程ｅ）を省略したこと、及び実施例１の（工程ｆ）の代わりに以下に示す方法にて第１層のｂ層を形成したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表４－１、表４－２及び表８－２に示す。 <Example 23>
Except that (Step e) in Example 1 was omitted and that the first layer b was formed by the following method instead of (Step f) in Example 1, the same procedure as in Example 1 was performed. The conductive particles, the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced, and the conductive particles and the connection structure were evaluated. The results are shown in Table 4-1, Table 4-2 and Table 8-2.
　実施例２３では、まず、第１層のｂ層形成用の無電解ニッケルめっき液の液量を１００ｍｌとし、１００ｎｍの膜厚のニッケル－リン合金被膜からなる第１層のｂ層を形成した。第１層のｂ層を形成することにより得た粒子Ｄは４．５５ｇであった。 In Example 23, first, the amount of the electroless nickel plating solution for forming the first layer b was 100 ml, and a first layer b consisting of a nickel-phosphorus alloy film having a thickness of 100 nm was formed. The particle D obtained by forming the b layer of the first layer was 4.55 g.
＜実施例２４＞
　実施例１の（工程ｅ）、（工程ｆ）の代わりに以下に示す方法にて第１層のａ層、ｂ層を形成したこと以外は実施例１と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表４－１、表４－２及び表８－２に示す。 <Example 24>
In the same manner as in Example 1 except that the first layer a and b were formed by the following method instead of (Step e) and (Step f) in Example 1, conductive particles and insulating coatings were formed. Production of conductive particles, anisotropic conductive adhesive films and connection structures, and evaluation of conductive particles and connection structures were performed. The results are shown in Table 4-1, Table 4-2 and Table 8-2.
　まず、工程ｄで得た粒子Ｂ分散液を、８０℃に加温した水１０００ｍＬで希釈した後、めっき安定剤として１ｇ／Ｌの硝酸ビスマス水溶液を１ｍＬ添加した。次に、粒子Ｂ分散液に、下記組成のａ層形成用の無電解ニッケルめっき液２０ｍＬを５ｍＬ／分の滴下速度で滴下した。第１層のａ層形成用の無電解ニッケルめっき液の組成は以下の通りである。
　　硫酸ニッケル・・・・・・・・・・・・４００ｇ／Ｌ
　　次亜リン酸ナトリウム・・・・・・・・１５０ｇ／Ｌ
　　酢酸・・・・・・・・・・・・・・・・１２０ｇ／Ｌ
　　硝酸ビスマス水溶液（１ｇ／Ｌ）・・・１ｍＬ／Ｌ First, after the particle B dispersion obtained in step d was diluted with 1000 mL of water heated to 80 ° C., 1 mL of a 1 g / L bismuth nitrate aqueous solution was added as a plating stabilizer. Next, 20 mL of electroless nickel plating solution for forming a layer having the following composition was dropped into the particle B dispersion at a dropping rate of 5 mL / min. The composition of the electroless nickel plating solution for forming the first layer a is as follows.
Nickel sulfate ... 400g / L
Sodium hypophosphite ... 150g / L
Acetic acid ... 120g / L
Bismuth nitrate aqueous solution (1 g / L) ... 1 mL / L
　第１層のａ層のめっき液を滴下終了後、３分後に、下記組成のｂ層形成用のめっき液８０ｍＬを５ｍＬ／分の滴下速度で滴下した。滴下終了後、１０分間経過した後に、めっき液を加えた分散液を濾過した。濾過物を水で洗浄した後、８０℃の真空乾燥機で乾燥した。このようにして、表４－１に示す第１層のａ層が２０ｎｍ、第１層のｂ層が８０ｎｍの膜厚のニッケル－リン合金被膜からなる第１層を形成した。第１層のａ層およびｂ層を形成することにより得た粒子Ｄは、４．５５ｇであった。
（ｂ層形成用の無電解ニッケルめっき液）
　　硫酸ニッケル・・・・・・・・・・・・４００ｇ／Ｌ
　　次亜リン酸ナトリウム・・・・・・・・１５０ｇ／Ｌ
　　酒石酸ナトリウム・２水和物・・・・・６０ｇ／Ｌ
　　硝酸ビスマス水溶液（１ｇ／Ｌ）・・・１ｍＬ／Ｌ Three minutes after the completion of the dropping of the first-layer a-layer plating solution, 80 mL of a b-layer forming plating solution having the following composition was added dropwise at a dropping rate of 5 mL / min. After 10 minutes had elapsed after the completion of the dropping, the dispersion with the plating solution added was filtered. The filtrate was washed with water and then dried with a vacuum dryer at 80 ° C. In this way, a first layer composed of a nickel-phosphorus alloy film having a thickness of 20 nm for the first layer shown in Table 4-1 and a thickness of 80 nm for the first layer b was formed. The particle D obtained by forming the first layer a and b was 4.55 g.
(Electroless nickel plating solution for forming b layer)
Nickel sulfate ... 400g / L
Sodium hypophosphite ... 150g / L
Sodium tartrate dihydrate ... 60g / L
Bismuth nitrate aqueous solution (1 g / L) ... 1 mL / L
　実施例２４においては、ａ層のニッケルの濃度が９３．０質量％（残部リン）であり、ｂ層のニッケルの濃度は、導電粒子の表面に向かって徐々に高くなっていた。ｂ層の表面におけるニッケルの濃度は９７．５質量％（残部リン）だった。このように、ｂ層形成用の無電解ニッケルめっき液を、ａ層形成用の無電解ニッケルめっき液に直接加えることにより、除々にニッケル濃度が高くなる層を得ることが可能になる。そして、無電解ニッケルめっき皮膜形成時の初期に９４質量％以下の層を２０ｎｍ以上形成することにより、導電粒子同士は磁性の影響をほとんど受けないので、当該導電粒子同士の凝集を抑制することができる。また、実施例１のように、異なる組成のニッケル－リン合金被膜を２回に分けて形成する必要がなくなるため、短時間で導電粒子を作製することが可能となる。 In Example 24, the nickel concentration in the a layer was 93.0% by mass (remaining phosphorus), and the nickel concentration in the b layer gradually increased toward the surface of the conductive particles. The concentration of nickel on the surface of the b layer was 97.5% by mass (remaining phosphorus). Thus, by directly adding the electroless nickel plating solution for forming the b layer to the electroless nickel plating solution for forming the a layer, it becomes possible to obtain a layer having a gradually increasing nickel concentration. And by forming a layer of 94% by mass or less at 20 nm or more at the initial stage of forming the electroless nickel plating film, the conductive particles are hardly affected by magnetism, so that the aggregation of the conductive particles can be suppressed. it can. In addition, it is not necessary to form the nickel-phosphorus alloy film having different compositions in two steps as in Example 1, so that the conductive particles can be produced in a short time.
＜実施例２５＞
　実施例１の（工程ａ）～（工程ｆ）を経て作製した粒子Ｄ４．５５ｇを、下記組成の無電解パラジウムめっき液１Ｌ（ｐＨ：６）に浸漬し、第２層を形成した。反応時間は１０分間、温度は５０℃にて処理を行った。第２層の平均厚さは１０ｎｍ、第２層におけるパラジウム含有量は１００質量％であった。この導電粒子を用いたこと以外は実施例１と同様にして、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表４－３、表４－４及び表８－２に示す。無電解パラジウムめっき液の組成は以下の通りである。
　　塩化パラジウム・・・・・・・０．０７ｇ／Ｌ
　　ＥＤＴＡ・２ナトリウム・・・１ｇ／Ｌ
　　クエン酸・２ナトリウム・・・１ｇ／Ｌ
　　ギ酸ナトリウム・・・・・・・０．２ｇ／Ｌ <Example 25>
4.55 g of the particles D produced through (Step a) to (Step f) in Example 1 were immersed in 1 L (pH: 6) of an electroless palladium plating solution having the following composition to form a second layer. The reaction time was 10 minutes and the temperature was 50 ° C. The average thickness of the second layer was 10 nm, and the palladium content in the second layer was 100% by mass. Except for using these conductive particles, the insulation coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced in the same manner as in Example 1, and the conductive particles and the connection structure were evaluated. The results are shown in Table 4-3, Table 4-4 and Table 8-2. The composition of the electroless palladium plating solution is as follows.
Palladium chloride ... 0.07g / L
EDTA · 2 sodium ・ ・ ・ 1g / L
Citric acid ・ disodium ・ ・ ・ 1g / L
Sodium formate ... 0.2g / L
＜実施例２６＞
　実施例１の（工程ａ～工程ｆ）を経て作製した粒子Ｄ４．５５ｇを、置換金めっき液（日立化成株式会社製、商品名「ＨＧＳ－１００」）１００ｍＬ／Ｌの溶液１Ｌに、８５℃で２分間浸漬し、更に２分間水洗して、第２層を形成した。反応時間は１０分間、温度は６０℃にて処理を行った。第２層の平均厚さは１０ｎｍ、第２層における金含有量はほぼ１００質量％であった。この導電粒子を用いたこと以外は実施例１と同様にして、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表４－３、表４－４及び表８－２に示す。 <Example 26>
4.55 g of the particles D produced through (Step a to Step f) of Example 1 were added to 1 L of a solution of a substitution gold plating solution (trade name “HGS-100”, manufactured by Hitachi Chemical Co., Ltd.) at 85 ° C. at 85 ° C. For 2 minutes and then washed with water for 2 minutes to form a second layer. The reaction time was 10 minutes and the temperature was 60 ° C. The average thickness of the second layer was 10 nm, and the gold content in the second layer was approximately 100% by mass. Except for using these conductive particles, the insulation coated conductive particles, the anisotropic conductive adhesive film and the connection structure were produced in the same manner as in Example 1, and the conductive particles and the connection structure were evaluated. The results are shown in Table 4-3, Table 4-4 and Table 8-2.
＜比較例１＞
　まず、実施例１の（工程ａ）を行った。次に、平均粒子径１００ｎｍのコロイダルシリカ分散液を超純水で希釈して、０．３３質量％シリカ粒子分散液（シリカ総量０．０５ｇ）を得た。当該分散液に、（工程ａ）で作製したポリエチレンイミンが吸着した樹脂粒子を加え、室温で１５分攪拌した。その後φ３μｍのメンブレンフィルタ（メルクミリポア社製）を用いた濾過により樹脂粒子を取り出した。濾液からシリカは抽出されなかったことから、実質的に全てのシリカ粒子が樹脂粒子に吸着したことが確認された。シリカ粒子が吸着した樹脂粒子を超純水２００ｇに入れて室温で５分攪拌した。その後、φ３μｍのメンブレンフィルタ（メルクミリポア社製）を用いた濾過により樹脂粒子を取り出し、メンブレンフィルタ上の樹脂粒子を２００ｇの超純水で２回洗浄した。洗浄後の樹脂粒子を８０℃で３０分、１２０℃で１時間の順に加熱することにより乾燥して、表面にシリカ粒子が吸着した樹脂粒子２．０５ｇを得た。 <Comparative Example 1>
First, (Step a) of Example 1 was performed. Next, a colloidal silica dispersion having an average particle diameter of 100 nm was diluted with ultrapure water to obtain a 0.33% by mass silica particle dispersion (total amount of silica: 0.05 g). Resin particles adsorbed with the polyethyleneimine prepared in (Step a) were added to the dispersion and stirred at room temperature for 15 minutes. Thereafter, the resin particles were taken out by filtration using a φ3 μm membrane filter (manufactured by Merck Millipore). Since silica was not extracted from the filtrate, it was confirmed that substantially all silica particles were adsorbed on the resin particles. Resin particles adsorbed with silica particles were placed in 200 g of ultrapure water and stirred at room temperature for 5 minutes. Thereafter, resin particles were taken out by filtration using a φ3 μm membrane filter (manufactured by Merck Millipore), and the resin particles on the membrane filter were washed twice with 200 g of ultrapure water. The washed resin particles were dried by heating at 80 ° C. for 30 minutes and 120 ° C. for 1 hour in order to obtain 2.05 g of resin particles having silica particles adsorbed on the surface.
　上記樹脂粒子２．０５ｇを、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を１５分間照射した後、パラジウム触媒（アトテックジャパン株式会社製、商品名「アトテックネオガント８３４」）を８質量％含有するパラジウム触媒化液１００ｍＬに添加して、超音波を照射しながら３０℃で３０分攪拌した。その後、φ３μｍのメンブレンフィルタ（メルクミリポア社製）を用いた濾過により樹脂粒子を取出し、取り出された樹脂粒子を水洗した。水洗後の樹脂粒子を、ｐＨ６．０に調整された０．５質量％ジメチルアミンボラン液に添加し、パラジウム触媒が固着化された樹脂粒子２．０１ｇを得た。そして、２０ｍＬの蒸留水に、パラジウム触媒が固着化された樹脂粒子２．０１ｇを浸漬した後、超音波分散することで、樹脂粒子分散液を得た。超音波分散した後の粒子をＳＥＭにより観察した結果を図１５に示す。 After irradiating 2.05 g of the resin particles with an ultrasonic wave having a resonance frequency of 28 kHz and an output of 100 W for 15 minutes, a palladium catalyst containing 8% by mass of a palladium catalyst (manufactured by Atotech Japan Co., Ltd., trade name “Atotech Neogant 834”). The solution was added to 100 mL of the chemical solution and stirred at 30 ° C. for 30 minutes while irradiating with ultrasonic waves. Thereafter, the resin particles were removed by filtration using a φ3 μm membrane filter (manufactured by Merck Millipore), and the removed resin particles were washed with water. The resin particles after washing with water were added to a 0.5 mass% dimethylamine borane solution adjusted to pH 6.0 to obtain 2.01 g of resin particles to which a palladium catalyst was fixed. Then, 2.01 g of resin particles having a palladium catalyst fixed thereon were immersed in 20 mL of distilled water, and then ultrasonically dispersed to obtain a resin particle dispersion. The result of observing the particles after ultrasonic dispersion by SEM is shown in FIG.
　これ以降は、実施例１の（工程ｅ）以降と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表５－１、表５－２及び表９－１に示す。比較例１における（工程ｆ）の後の導電粒子をＳＥＭにより観察した結果を図１６に示す。 Thereafter, in the same manner as in (step e) onward in Example 1, the production of conductive particles, insulating coated conductive particles, anisotropic conductive adhesive films and connection structures, and evaluation of the conductive particles and connection structures were performed. went. The results are shown in Table 5-1, Table 5-2 and Table 9-1. The result of having observed the electroconductive particle after the (process f) in the comparative example 1 by SEM is shown in FIG.
＜比較例２＞
　まず、実施例１の（工程ａ）を行った。次に、ポリエチレンイミンが吸着した樹脂粒子２ｇをメタノール中に入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながら室温で５分間攪拌した。その後、実施例５と同一の平均粒径１００ｎｍの気相法親水性球状シリカ粉末を０．０５ｇ入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながらさらに室温で５分間攪拌することで、シリカが吸着された樹脂粒子を得た。シリカが吸着された樹脂粒子は２．０５ｇであった。 <Comparative Example 2>
First, (Step a) of Example 1 was performed. Next, 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Then, 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 100 nm as in Example 5 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Resin particles on which silica was adsorbed were obtained. The amount of resin particles on which silica was adsorbed was 2.05 g.
　上記樹脂粒子２．０５ｇを、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を１５分間照射した後、パラジウム触媒（アトテックジャパン株式会社製、商品名「アトテックネオガント８３４」）を８質量％含有するパラジウム触媒化液１００ｍＬに添加して、超音波を照射しながら３０℃で３０分攪拌した。その後、φ３μｍのメンブレンフィルタ（メルクミリポア社製）を用いた濾過により樹脂粒子を取出し、取り出された樹脂粒子を水洗した。水洗後の樹脂粒子を、ｐＨ６．０に調整された０．５質量％ジメチルアミンボラン液に添加し、パラジウム触媒が固着化された樹脂粒子２．０１ｇを得た。そして、２０ｍＬの蒸留水に、パラジウム触媒が固着化された樹脂粒子２．０１ｇを浸漬した後、超音波分散することで、樹脂粒子分散液を得た。 After irradiating 2.05 g of the resin particles with an ultrasonic wave having a resonance frequency of 28 kHz and an output of 100 W for 15 minutes, a palladium catalyst containing 8% by mass of a palladium catalyst (manufactured by Atotech Japan Co., Ltd., trade name “Atotech Neogant 834”). The solution was added to 100 mL of the chemical solution and stirred at 30 ° C. for 30 minutes while irradiating with ultrasonic waves. Thereafter, the resin particles were removed by filtration using a φ3 μm membrane filter (manufactured by Merck Millipore), and the removed resin particles were washed with water. The resin particles after washing with water were added to a 0.5 mass% dimethylamine borane solution adjusted to pH 6.0 to obtain 2.01 g of resin particles to which a palladium catalyst was fixed. Then, 2.01 g of resin particles having a palladium catalyst fixed thereon were immersed in 20 mL of distilled water, and then ultrasonically dispersed to obtain a resin particle dispersion.
　これ以降は、実施例１の（工程ｅ）以降と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表５－１、表５－２及び表９－１に示す。 Thereafter, in the same manner as in (step e) onward in Example 1, the production of conductive particles, insulating coated conductive particles, anisotropic conductive adhesive films and connection structures, and evaluation of the conductive particles and connection structures were performed. went. The results are shown in Table 5-1, Table 5-2 and Table 9-1.
＜比較例３＞
　まず、実施例１の（工程ａ）を行った。次に、ポリエチレンイミンが吸着した樹脂粒子２ｇをメタノール中に入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながら室温で５分間攪拌した。その後、実施例２と同一の平均粒径２５ｎｍの気相法親水性球状シリカ粉末を０．０５ｇ入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながらさらに室温で５分間攪拌することで、シリカが吸着された樹脂粒子を得た。シリカが吸着された樹脂粒子は２．０５ｇであった。 <Comparative Example 3>
First, (Step a) of Example 1 was performed. Next, 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Then, 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 25 nm as in Example 2 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Resin particles on which silica was adsorbed were obtained. The amount of resin particles on which silica was adsorbed was 2.05 g.
　これ以降は、実施例１の（工程ｄ）以降と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表５－１、表５－２及び表９－１に示す。 Thereafter, in the same manner as in (step d) onward in Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive films, and connection structures were manufactured, and the conductive particles and connection structures were evaluated. went. The results are shown in Table 5-1, Table 5-2 and Table 9-1.
＜比較例４＞
　まず、実施例１の（工程ａ）を行った。次に、ポリエチレンイミンが吸着した樹脂粒子２ｇをメタノール中に入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながら室温で５分間攪拌した。その後、実施例１と同一の平均粒径６０ｎｍの気相法親水性球状シリカ粉末を０．０５ｇ入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながらさらに室温で５分間攪拌することで、シリカが吸着された樹脂粒子を得た。シリカが吸着された樹脂粒子は２．０５ｇであった。 <Comparative Example 4>
First, (Step a) of Example 1 was performed. Next, 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Then, 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 60 nm as in Example 1 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Resin particles on which silica was adsorbed were obtained. The amount of resin particles on which silica was adsorbed was 2.05 g.
　これ以降は、実施例１の（工程ｄ）以降と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表５－１、表５－２及び表９－１に示す。 Thereafter, in the same manner as in (step d) onward in Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive films, and connection structures were manufactured, and the conductive particles and connection structures were evaluated. went. The results are shown in Table 5-1, Table 5-2 and Table 9-1.
＜比較例５＞
　まず、実施例１の（工程ａ）を行った。次に、ポリエチレンイミンが吸着した樹脂粒子２ｇをメタノール中に入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながら室温で５分間攪拌した。その後、実施例５と同一の平均粒径１００ｎｍの気相法親水性球状シリカ粉末を０．０５ｇ入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながらさらに室温で５分間攪拌することで、シリカが吸着された樹脂粒子を得た。シリカが吸着された樹脂粒子は２．０５ｇであった。 <Comparative Example 5>
First, (Step a) of Example 1 was performed. Next, 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Then, 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 100 nm as in Example 5 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Resin particles on which silica was adsorbed were obtained. The amount of resin particles on which silica was adsorbed was 2.05 g.
　これ以降は、実施例１の（工程ｄ）以降と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表５－３、表５－４及び表９－２に示す。 Thereafter, in the same manner as in (step d) onward in Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive films, and connection structures were manufactured, and the conductive particles and connection structures were evaluated. went. The results are shown in Table 5-3, Table 5-4 and Table 9-2.
＜比較例６＞
　まず、実施例１の（工程ａ）を行った。次に、ポリエチレンイミンが吸着した樹脂粒子２ｇをメタノール中に入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながら室温で５分間攪拌した。その後、実施例６と同一の平均粒径１２０ｎｍの気相法親水性球状シリカ粉末を０．０５ｇ入れ、共振周波数２８ｋＨｚ、出力１００Ｗの超音波を照射しながらさらに室温で５分間攪拌することで、シリカが吸着された樹脂粒子を得た。シリカが吸着された樹脂粒子は２．０５ｇであった。 <Comparative Example 6>
First, (Step a) of Example 1 was performed. Next, 2 g of resin particles adsorbed with polyethyleneimine were put in methanol and stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Thereafter, 0.05 g of vapor phase method hydrophilic spherical silica powder having the same average particle diameter of 120 nm as in Example 6 was added, and further stirred at room temperature for 5 minutes while irradiating ultrasonic waves with a resonance frequency of 28 kHz and an output of 100 W. Resin particles on which silica was adsorbed were obtained. The amount of resin particles on which silica was adsorbed was 2.05 g.
　これ以降は、実施例１の（工程ｄ）以降と同様にして、導電粒子、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、導電粒子及び接続構造体の評価を行った。結果を表５－３、表５－４及び表９－２に示す。 Thereafter, in the same manner as in (step d) onward in Example 1, conductive particles, insulating coated conductive particles, anisotropic conductive adhesive films, and connection structures were manufactured, and the conductive particles and connection structures were evaluated. went. The results are shown in Table 5-3, Table 5-4 and Table 9-2.
＜比較例７＞
　平均粒径３．０μｍの架橋ポリスチレン粒子（株式会社日本触媒製、商品名「ソリオスター」）を樹脂粒子として用いた。４００ｍＬのクリーナーコンディショナー２３１水溶液（ローム・アンド・ハース電子材料株式会社製、濃度４０ｍＬ／Ｌ）を攪拌しながら、そこに樹脂粒子３０ｇを投入した。続いて、水溶液を６０℃に加温し、超音波を与えながら３０分間攪拌して、樹脂粒子の表面改質及び分散処理を行った。 <Comparative Example 7>
Cross-linked polystyrene particles having an average particle size of 3.0 μm (trade name “Soliostar” manufactured by Nippon Shokubai Co., Ltd.) were used as resin particles. While stirring 400 mL of the cleaner conditioner 231 aqueous solution (Rohm and Haas Electronic Materials Co., Ltd., concentration: 40 mL / L), 30 g of resin particles were added thereto. Subsequently, the aqueous solution was heated to 60 ° C. and stirred for 30 minutes while applying ultrasonic waves to perform surface modification and dispersion treatment of the resin particles.
　上記水溶液を濾過し、得られた粒子を１回水洗した後に、粒子３０ｇを水に分散させて２００ｍＬのスラリーを得た。このスラリーに塩化第一錫水溶液２００ｍＬ（濃度１．５ｇ／Ｌ）を加え、常温で５分間攪拌し、錫イオンを粒子の表面に吸着させる感受性化処理を行った。続いて、水溶液を濾過し、得られた粒子を１回水洗した。次いで、粒子３０ｇを水に分散させて４００ｍＬのスラリーを調製した後、６０℃まで加温した。超音波を併用してスラリーを攪拌しながら、１０ｇ／Ｌの塩化パラジウム水溶液２ｍＬを添加した。そのまま５分間攪拌することで、粒子の表面にパラジウムイオンを捕捉させる活性化処理を行った。続いて、水溶液を濾過し、得られた粒子を１回水洗した。 The aqueous solution was filtered and the obtained particles were washed once with water, and then 30 g of the particles were dispersed in water to obtain 200 mL of slurry. To this slurry, 200 mL of stannous chloride aqueous solution (concentration: 1.5 g / L) was added and stirred for 5 minutes at room temperature to perform sensitization treatment for adsorbing tin ions on the surface of the particles. Subsequently, the aqueous solution was filtered, and the resulting particles were washed once with water. Next, 30 g of particles were dispersed in water to prepare a 400 mL slurry, and then heated to 60 ° C. While stirring the slurry using ultrasonic waves, 2 mL of a 10 g / L palladium chloride aqueous solution was added. The mixture was stirred for 5 minutes as it was to perform an activation treatment for trapping palladium ions on the surface of the particles. Subsequently, the aqueous solution was filtered, and the resulting particles were washed once with water.
　次いで、２０ｇ／Ｌの酒石酸ナトリウム、１０ｇ／Ｌの硫酸ニッケル及び０．５ｇ／Ｌの次亜リン酸ナトリウムを溶解した水溶液からなる無電解めっき液３リットルを６０℃に昇温した。この無電解めっき液に、上記粒子１０ｇを投入した。これを５分間攪拌し、水素の発泡が停止することを確認した。 Subsequently, 3 liters of electroless plating solution composed of an aqueous solution in which 20 g / L sodium tartrate, 10 g / L nickel sulfate and 0.5 g / L sodium hypophosphite were dissolved was heated to 60 ° C. The electroless plating solution was charged with 10 g of the particles. This was stirred for 5 minutes, and it was confirmed that hydrogen foaming stopped.
　その後、２００ｇ／Ｌの硫酸ニッケル水溶液４００ｍＬと、２００ｇ／Ｌの次亜リン酸ナトリウム及び９０ｇ／Ｌの水酸化ナトリウム混合水溶液４００ｍＬとを、それぞれ同時に定量ポンプによって連続的に、粒子を含むめっき液に添加した。添加速度はいずれも３ｍＬ／分とした。次いで、この溶液を６０℃に保持しながら５分間攪拌した後、溶液を濾過した。濾過物を３回洗浄した後、１００℃の真空乾燥機で乾燥して、ニッケル－リン合金被膜を有する導電粒子を得た。得られた導電粒子について、粒子の中心付近を通るようにウルトラミクロトーム法で断面を切り出し、ＴＥＭを用いて２５万倍の倍率で観察した。得られた断面の画像に基づき、断面積の平均値より膜厚を算出した結果、ニッケル－リン合金被膜の平均膜厚は１０５ｎｍであった。 Thereafter, a 200 g / L nickel sulfate aqueous solution (400 mL) and a 200 g / L sodium hypophosphite and 90 g / L sodium hydroxide mixed aqueous solution (400 mL) were each simultaneously and continuously converted into a plating solution containing particles by a metering pump. Added. The addition rate was 3 mL / min. The solution was then stirred for 5 minutes while maintaining the temperature at 60 ° C., and then the solution was filtered. The filtrate was washed three times and then dried with a vacuum dryer at 100 ° C. to obtain conductive particles having a nickel-phosphorus alloy coating. About the obtained electroconductive particle, the cross section was cut out by the ultra microtome method so that it might pass through center vicinity of particle | grains, and it observed at 250,000 times magnification using TEM. As a result of calculating the film thickness from the average value of the cross-sectional areas based on the obtained cross-sectional image, the average film thickness of the nickel-phosphorus alloy film was 105 nm.
　この導電粒子を用いたこと以外は実施例１と同様にして、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、接続構造体の評価を行った。導電粒子の評価については、一部の評価を実施例１と同様に行った。結果を表５－３、表５－４及び表９－２に示す。 The production of the insulating coated conductive particles, the anisotropic conductive adhesive film and the connection structure, and the evaluation of the connection structure were performed in the same manner as in Example 1 except that this conductive particle was used. Regarding the evaluation of the conductive particles, a part of the evaluation was performed in the same manner as in Example 1. The results are shown in Table 5-3, Table 5-4 and Table 9-2.
＜比較例８＞
　平均粒径３．０μｍの架橋ポリスチレン粒子（株式会社日本触媒製、商品名「ソリオスター」）を樹脂粒子として用いた。４００ｍＬのクリーナーコンディショナー２３１水溶液（ローム・アンド・ハース電子材料株式会社製、濃度４０ｍＬ／Ｌ）を攪拌しながら、そこに樹脂粒子７ｇを投入した。続いて、水溶液を６０℃に加温し、超音波を与えながら３０分間攪拌して、樹脂粒子の表面改質及び分散処理を行った。 <Comparative Example 8>
Cross-linked polystyrene particles having an average particle size of 3.0 μm (trade name “Soliostar” manufactured by Nippon Shokubai Co., Ltd.) were used as resin particles. While stirring 400 mL of the cleaner conditioner 231 aqueous solution (Rohm and Haas Electronic Materials Co., Ltd., concentration: 40 mL / L), 7 g of resin particles were added thereto. Subsequently, the aqueous solution was heated to 60 ° C. and stirred for 30 minutes while applying ultrasonic waves to perform surface modification and dispersion treatment of the resin particles.
　上記水溶液を濾過し、得られた粒子を１回水洗した後に、粒子７ｇを純水に分散させて２００ｍＬのスラリーを得た。このスラリーに塩化第一錫水溶液２００ｍＬ（濃度１．５ｇ／Ｌ）を加え、常温で５分間攪拌し、錫イオンを粒子の表面に吸着させる感受性化処理を行った。続いて、水溶液を濾過し、得られた粒子を１回水洗した。次いで、粒子７ｇを水に分散させて４００ｍＬのスラリーを調製した後、６０℃まで加温した。超音波を併用してスラリーを攪拌しながら、１０ｇ／Ｌの塩化パラジウム水溶液２ｍＬを添加した。そのまま５分間攪拌することで、粒子の表面にパラジウムイオンを捕捉させる活性化処理を行った。続いて、水溶液を濾過し、得られた粒子を１回水洗した。 The aqueous solution was filtered, and the obtained particles were washed once, and then 7 g of the particles were dispersed in pure water to obtain 200 mL of slurry. To this slurry, 200 mL of stannous chloride aqueous solution (concentration: 1.5 g / L) was added and stirred for 5 minutes at room temperature to perform sensitization treatment for adsorbing tin ions on the surface of the particles. Subsequently, the aqueous solution was filtered, and the resulting particles were washed once with water. Next, 7 g of particles were dispersed in water to prepare a 400 mL slurry, and then heated to 60 ° C. While stirring the slurry using ultrasonic waves, 2 mL of a 10 g / L palladium chloride aqueous solution was added. The mixture was stirred for 5 minutes as it was to perform an activation treatment for trapping palladium ions on the surface of the particles. Subsequently, the aqueous solution was filtered, and the resulting particles were washed once with water.
　得られた粒子７ｇを純水３００ｍＬに加え、３分間攪拌して分散させた。次に、その分散液に芯物質としてニッケル粒子（三井金属鉱業株式会社製、商品名「２００７ＳＵＳ」、平均粒径５０ｎｍ）２．２５ｇを添加し、芯物質を付着させた粒子を得た。 7 g of the obtained particles were added to 300 mL of pure water and dispersed by stirring for 3 minutes. Next, 2.25 g of nickel particles (trade name “2007SUS”, average particle diameter of 50 nm, manufactured by Mitsui Mining & Smelting Co., Ltd.) were added as a core material to the dispersion to obtain particles to which the core material was adhered.
　前記分散液を更に水１２００ｍＬで希釈し、めっき安定剤として硝酸ビスマス水溶液（濃度１ｇ／Ｌ）４ｍＬを添加した。次に、この分散液に、硫酸ニッケル４５０ｇ／Ｌ、次亜リン酸ナトリウム１５０ｇ／Ｌ、クエン酸ナトリウム１１６ｇ／Ｌ及びめっき安定剤（硝酸ビスマス水溶液（濃度１ｇ／Ｌ））６ｍＬの混合溶液１２０ｍＬを８１ｍＬ／分の添加速度で定量ポンプを通して添加した。その後、ｐＨが安定するまで攪拌し、水素の発泡が停止することを確認した。 The dispersion was further diluted with 1200 mL of water, and 4 mL of a bismuth nitrate aqueous solution (concentration 1 g / L) was added as a plating stabilizer. Next, 120 mL of a mixed solution of nickel sulfate 450 g / L, sodium hypophosphite 150 g / L, sodium citrate 116 g / L, and plating stabilizer (bismuth nitrate aqueous solution (concentration 1 g / L)) 6 mL was added to this dispersion. The addition was made through a metering pump at an addition rate of 81 mL / min. Then, it stirred until pH became stable and it confirmed that foaming of hydrogen stopped.
　次いで、硫酸ニッケル４５０ｇ／Ｌ、次亜リン酸ナトリウム１５０ｇ／Ｌ、クエン酸ナトリウム１１６ｇ／Ｌ、めっき安定剤（硝酸ビスマス水溶液（濃度１ｇ／Ｌ））３５ｍＬの混合溶液６５０ｍＬを２７ｍＬ／分の添加速度で定量ポンプを通して添加した。その後、ｐＨが安定するまで攪拌し、水素の発泡が停止することを確認した。 Next, an addition rate of 650 mL of a mixed solution of nickel sulfate 450 g / L, sodium hypophosphite 150 g / L, sodium citrate 116 g / L, and 35 mL of a plating stabilizer (bismuth nitrate aqueous solution (concentration 1 g / L)) is 27 mL / min. Was added through a metering pump. Then, it stirred until pH became stable and it confirmed that foaming of hydrogen stopped.
　次いで、めっき液を濾過し、濾過物を水で洗浄した。その後、８０℃の真空乾燥機で乾燥してニッケル－リン合金被膜を有する導電粒子を得た。得られた導電粒子について、粒子の中心付近を通るようにウルトラミクロトーム法で断面を切り出し、ＴＥＭを用いて２５万倍の倍率で観察した。得られた断面の画像に基づき、断面積の平均値より膜厚を算出した結果、ニッケル－リン合金被膜の平均膜厚は１０１ｎｍであった。 Next, the plating solution was filtered, and the filtrate was washed with water. Thereafter, the particles were dried with a vacuum dryer at 80 ° C. to obtain conductive particles having a nickel-phosphorus alloy coating. About the obtained electroconductive particle, the cross section was cut out by the ultra microtome method so that it might pass through center vicinity of particle | grains, and it observed at 250,000 times magnification using TEM. As a result of calculating the film thickness from the average value of the cross-sectional areas based on the obtained cross-sectional images, the average film thickness of the nickel-phosphorus alloy coating was 101 nm.
　上記導電粒子を用いたこと以外は実施例１と同様にして、絶縁被覆導電粒子、異方導電性接着フィルム及び接続構造体の作製、並びに、接続構造体の評価を行った。導電粒子の評価については、一部の評価を実施例１と同様に行った。結果を表５－３、表５－４及び表９－２に示す。 The production of the insulation coated conductive particles, the anisotropic conductive adhesive film and the connection structure, and the evaluation of the connection structure were performed in the same manner as in Example 1 except that the conductive particles were used. Regarding the evaluation of the conductive particles, a part of the evaluation was performed in the same manner as in Example 1. The results are shown in Table 5-3, Table 5-4 and Table 9-2.
　比較例１は上記特許文献３の導電粒子に対応する。比較例７の導電粒子は上記特許文献１の導電粒子に対応する。比較例８の導電粒子は上記特許文献２の導電粒子に対応する。 Comparative Example 1 corresponds to the conductive particles of Patent Document 3 above. The conductive particles of Comparative Example 7 correspond to the conductive particles of Patent Document 1. The conductive particles of Comparative Example 8 correspond to the conductive particles of Patent Document 2.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000016
Figure JPOXMLDOC01-appb-T000016
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000018
Figure JPOXMLDOC01-appb-T000018
Figure JPOXMLDOC01-appb-T000019
Figure JPOXMLDOC01-appb-T000019
Figure JPOXMLDOC01-appb-T000020
Figure JPOXMLDOC01-appb-T000020
Figure JPOXMLDOC01-appb-T000021
Figure JPOXMLDOC01-appb-T000021
Figure JPOXMLDOC01-appb-T000022
Figure JPOXMLDOC01-appb-T000022
Figure JPOXMLDOC01-appb-T000023
Figure JPOXMLDOC01-appb-T000023
Figure JPOXMLDOC01-appb-T000024
Figure JPOXMLDOC01-appb-T000024
Figure JPOXMLDOC01-appb-T000025
Figure JPOXMLDOC01-appb-T000025
Figure JPOXMLDOC01-appb-T000026
Figure JPOXMLDOC01-appb-T000026
Figure JPOXMLDOC01-appb-T000027
Figure JPOXMLDOC01-appb-T000027
Figure JPOXMLDOC01-appb-T000028
Figure JPOXMLDOC01-appb-T000028
Figure JPOXMLDOC01-appb-T000029
Figure JPOXMLDOC01-appb-T000029
Figure JPOXMLDOC01-appb-T000030
Figure JPOXMLDOC01-appb-T000030
　１００ａ，１００ｂ，４００…導電粒子、１０１…樹脂粒子、１０２…非導電性無機粒子、１０３…複合粒子、１０４…第１層、１０５…第２層、１０９…突起、２００…絶縁被覆導電粒子、２１０…絶縁性粒子（絶縁性被覆部）、３００…接続構造体、３１０…第１回路部材、３１１，３２１…回路基板、３１１ａ，３２１ａ…主面、３１２，３２２…回路電極、３２０…第２回路部材、３３０…接続部、３３０ａ…異方導電性接着剤、３３２…硬化物、３３２ａ…接着剤、４０１…異常析出部。 100a, 100b, 400 ... conductive particles, 101 ... resin particles, 102 ... non-conductive inorganic particles, 103 ... composite particles, 104 ... first layer, 105 ... second layer, 109 ... projections, 200 ... insulating coated conductive particles, 210: Insulating particles (insulating coating), 300: Connection structure, 310: First circuit member, 311, 321 ... Circuit board, 311a, 321a ... Main surface, 312, 322 ... Circuit electrode, 320 ... Second Circuit member, 330... Connecting portion, 330 a... Anisotropic conductive adhesive, 332... Cured product, 332 a.

Claims (24)

  1. 　カチオン性ポリマーにより被覆された樹脂粒子、及び前記樹脂粒子の表面に配置される非導電性無機粒子を有する複合粒子と、
    　前記複合粒子を覆う金属層と、を備え、
    　前記非導電性無機粒子は、疎水化処理剤によって被覆されている、
    導電粒子。     Composite particles having resin particles coated with a cationic polymer and non-conductive inorganic particles disposed on the surface of the resin particles;
    A metal layer covering the composite particles,
    The non-conductive inorganic particles are coated with a hydrophobic treatment agent,
    Conductive particles.
  2. 　前記疎水化処理剤は、シラザン系疎水化処理剤、シロキサン系疎水化処理剤、シラン系疎水化処理剤、及びチタネート系疎水化処理剤からなる群より選ばれる、請求項１に記載の導電粒子。 The conductive particle according to claim 1, wherein the hydrophobizing agent is selected from the group consisting of a silazane hydrophobizing agent, a siloxane hydrophobizing agent, a silane hydrophobizing agent, and a titanate hydrophobizing agent. .
  3. 　前記疎水化処理剤は、ヘキサメチレンジシラザン、ポリジメチルシロキサン、及びＮ，Ｎ－ジメチルアミノトリメチルシランからなる群より選ばれる、請求項１又は２に記載の導電粒子。 The conductive particle according to claim 1 or 2, wherein the hydrophobizing agent is selected from the group consisting of hexamethylene disilazane, polydimethylsiloxane, and N, N-dimethylaminotrimethylsilane.
  4. 　メタノール滴定法による前記非導電性無機粒子の疎水化度は、３０％以上である、請求項１～３のいずれか一項に記載の導電粒子。 The conductive particles according to any one of claims 1 to 3, wherein the degree of hydrophobicity of the non-conductive inorganic particles by methanol titration is 30% or more.
  5. 　前記非導電性無機粒子は、静電気力によって前記樹脂粒子に接着されている、請求項１～４のいずれか一項に記載の導電粒子。 The conductive particles according to any one of claims 1 to 4, wherein the non-conductive inorganic particles are bonded to the resin particles by electrostatic force.
  6. 　前記樹脂粒子と前記非導電性無機粒子とのゼータ電位の差は、ｐＨ１以上ｐＨ１１以下において３０ｍＶ以上である、請求項１～５のいずれか一項に記載の導電粒子。 The conductive particles according to any one of claims 1 to 5, wherein a difference in zeta potential between the resin particles and the non-conductive inorganic particles is 30 mV or more at pH 1 or more and pH 11 or less.
  7. 　前記カチオン性ポリマーは、ポリアミン、ポリイミン、ポリアミド、ポリジアリルジメチルアンモニウムクロリド、ポリビニルアミン、ポリビニルピリジン、ポリビニルイミダゾール及びポリビニルピロリドンからなる群より選ばれる、請求項１～６のいずれか一項に記載の導電粒子。 The conductive polymer according to any one of claims 1 to 6, wherein the cationic polymer is selected from the group consisting of polyamine, polyimine, polyamide, polydiallyldimethylammonium chloride, polyvinylamine, polyvinylpyridine, polyvinylimidazole, and polyvinylpyrrolidone. particle.
  8. 　前記カチオン性ポリマーは、ポリエチレンイミンである、請求項１～６のいずれか一項に記載の導電粒子。 The conductive particle according to any one of claims 1 to 6, wherein the cationic polymer is polyethyleneimine.
  9. 　前記非導電性無機粒子の平均粒径は、２５ｎｍ以上１２０ｎｍ以下である、請求項１～８のいずれか一項に記載の導電粒子。 The conductive particles according to any one of claims 1 to 8, wherein the non-conductive inorganic particles have an average particle size of 25 nm or more and 120 nm or less.
  10. 　前記樹脂粒子の平均粒径は、１μｍ以上１０μｍ以下である、請求項１～９のいずれか一項に記載の導電粒子。 The conductive particles according to any one of claims 1 to 9, wherein an average particle size of the resin particles is 1 µm or more and 10 µm or less.
  11. 　前記非導電性無機粒子は、シリカ、ジルコニア、アルミナ、及びダイヤモンドからなる群より選ばれる、請求項１～１０のいずれか一項に記載の導電粒子。 The conductive particles according to any one of claims 1 to 10, wherein the non-conductive inorganic particles are selected from the group consisting of silica, zirconia, alumina, and diamond.
  12. 　前記金属層は、ニッケルを含有する第１層を有する、請求項１～１１のいずれか一項に記載の導電粒子。 The conductive particle according to any one of claims 1 to 11, wherein the metal layer has a first layer containing nickel.
  13. 　前記金属層は、前記第１層上に設けられる第２層を有し、
    　前記第２層は、貴金属及びコバルトからなる群より選ばれる金属を含有する、請求項１２に記載の導電粒子。     The metal layer has a second layer provided on the first layer,
    The conductive particle according to claim 12, wherein the second layer contains a metal selected from the group consisting of a noble metal and cobalt.
  14. 　第１回路電極を有する第１回路部材と、
    　前記第１回路部材に対向し、第２回路電極を有する第２回路部材と、
    　前記第１回路部材及び前記第２回路部材の間に配置され、請求項１～１３のいずれか一項に記載の導電粒子を含有する接続部と、
    を備え、
    　前記接続部は、前記第１回路電極と前記第２回路電極とが対向するように配置された状態で前記第１回路部材及び前記第２回路部材を互いに接続し、
    　前記第１回路電極と前記第２回路電極とは、変形した状態の前記導電粒子を介して互いに電気的に接続される、
    接続構造体。     A first circuit member having a first circuit electrode;
    A second circuit member facing the first circuit member and having a second circuit electrode;
    A connecting portion that is disposed between the first circuit member and the second circuit member and contains the conductive particles according to any one of claims 1 to 13,
    With
    The connecting portion connects the first circuit member and the second circuit member to each other in a state where the first circuit electrode and the second circuit electrode are arranged to face each other,
    The first circuit electrode and the second circuit electrode are electrically connected to each other through the conductive particles in a deformed state.
    Connection structure.
  15. 　請求項１～１３のいずれか一項に記載の導電粒子と、
    　当該導電粒子の前記金属層の外表面の少なくとも一部を被覆する絶縁性被覆部と、
    を備える絶縁被覆導電粒子。     Conductive particles according to any one of claims 1 to 13,
    An insulating covering for covering at least part of the outer surface of the metal layer of the conductive particles;
    Insulating coated conductive particles.
  16. 　第１回路電極を有する第１回路部材と、
    　前記第１回路部材に対向し、第２回路電極を有する第２回路部材と、
    　前記第１回路部材及び前記第２回路部材の間に配置され、請求項１５に記載の絶縁被覆導電粒子を含有する接続部と、を備え、
    　前記接続部は、前記第１回路電極と前記第２回路電極とが対向するように配置された状態で前記第１回路部材及び前記第２回路部材を互いに接続し、
    　前記第１回路電極と前記第２回路電極とは、変形した状態の前記絶縁被覆導電粒子を介して互いに電気的に接続される、
    接続構造体。     A first circuit member having a first circuit electrode;
    A second circuit member facing the first circuit member and having a second circuit electrode;
    A connection portion disposed between the first circuit member and the second circuit member and containing the insulating coated conductive particles according to claim 15,
    The connection portion connects the first circuit member and the second circuit member to each other in a state where the first circuit electrode and the second circuit electrode are arranged to face each other,
    The first circuit electrode and the second circuit electrode are electrically connected to each other through the insulating coating conductive particles in a deformed state.
    Connection structure.
  17. 　請求項１～１３のいずれか一項に記載の導電粒子と、
    　前記導電粒子が分散された接着剤と、
    を備える異方導電性接着剤。     Conductive particles according to any one of claims 1 to 13,
    An adhesive in which the conductive particles are dispersed;
    An anisotropic conductive adhesive comprising:
  18. 　請求項１５に記載の絶縁被覆導電粒子と、
    　前記絶縁被覆導電粒子が分散された接着剤と、
    を備える異方導電性接着剤。     Insulating coated conductive particles according to claim 15,
    An adhesive in which the insulating coating conductive particles are dispersed;
    An anisotropic conductive adhesive comprising:
  19. 　前記接着剤がフィルム状である、請求項１７又は１８に記載の異方導電性接着剤。 The anisotropic conductive adhesive according to claim 17 or 18, wherein the adhesive is in a film form.
  20. 　第１回路電極を有する第１回路部材と、
    　前記第１回路部材に対向し、第２回路電極を有する第２回路部材と、
    　前記第１回路部材及び前記第２回路部材を接着する、請求項１７～１９のいずれか一項に記載の異方導電性接着剤と、
    を備え、
    　前記第１回路電極と前記第２回路電極とは、互いに対向すると共に、前記異方導電性接着剤によって互いに電気的に接続される、
    接続構造体。     A first circuit member having a first circuit electrode;
    A second circuit member facing the first circuit member and having a second circuit electrode;
    An anisotropic conductive adhesive according to any one of claims 17 to 19, which bonds the first circuit member and the second circuit member;
    With
    The first circuit electrode and the second circuit electrode face each other and are electrically connected to each other by the anisotropic conductive adhesive,
    Connection structure.
  21. 　樹脂粒子をカチオン性ポリマーにより被覆する第１被覆工程と、
    　非導電性無機粒子を疎水化処理剤によって被覆する第２被覆工程と、
    　前記樹脂粒子の表面に前記非導電性無機粒子を静電気力により接着し、複合粒子を形成する粒子形成工程と、
    　前記複合粒子を金属層によって被覆する第３被覆工程と、
    を備える、導電粒子の製造方法。     A first coating step of coating resin particles with a cationic polymer;
    A second coating step of coating non-conductive inorganic particles with a hydrophobizing agent;
    A particle forming step of adhering the non-conductive inorganic particles to the surface of the resin particles by electrostatic force to form composite particles;
    A third coating step of coating the composite particles with a metal layer;
    A method for producing conductive particles.
  22. 　前記第３被覆工程では、無電解めっきにより前記複合粒子をニッケルを含有する第１層によって被覆する、請求項２１に記載の導電粒子の製造方法。 The method for producing conductive particles according to claim 21, wherein in the third coating step, the composite particles are coated with a first layer containing nickel by electroless plating.
  23. 　第３被覆工程では、貴金属及びコバルトからなる群より選ばれる金属を含有する第２層によって前記第１層に覆われた前記複合粒子を被覆する、請求項２２に記載の導電粒子の製造方法。 The method for producing conductive particles according to claim 22, wherein in the third coating step, the composite particles covered with the first layer are covered with a second layer containing a metal selected from the group consisting of a noble metal and cobalt.
  24. 　前記樹脂粒子と前記非導電性無機粒子とのゼータ電位の差は、ｐＨ１以上ｐＨ１１以下において３０ｍＶ以上である、請求項２１～２３のいずれか一項に記載の導電粒子の製造方法。 The method for producing conductive particles according to any one of claims 21 to 23, wherein a difference in zeta potential between the resin particles and the non-conductive inorganic particles is 30 mV or more at pH 1 or more and pH 11 or less.
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