WO2024034386A1 - Electroconductive particles, electroconductive material, and connection structure - Google Patents

Electroconductive particles, electroconductive material, and connection structure Download PDF

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Publication number
WO2024034386A1
WO2024034386A1 PCT/JP2023/027151 JP2023027151W WO2024034386A1 WO 2024034386 A1 WO2024034386 A1 WO 2024034386A1 JP 2023027151 W JP2023027151 W JP 2023027151W WO 2024034386 A1 WO2024034386 A1 WO 2024034386A1
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Prior art keywords
conductive layer
conductive
tin
particles
conductive particles
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PCT/JP2023/027151
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French (fr)
Japanese (ja)
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翔大 白石
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積水化学工業株式会社
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Publication of WO2024034386A1 publication Critical patent/WO2024034386A1/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 conductive particles having a base particle and a conductive layer disposed on the surface of the base particle.
  • the present invention also relates to a conductive material and a connected structure using the conductive particles described above.
  • Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known.
  • anisotropic conductive material conductive particles are dispersed in a binder resin. Further, as the conductive particles, conductive particles having a base particle and a conductive portion disposed on the surface of the base particle may be used.
  • the above-mentioned anisotropic conductive material is used to obtain various connected structures. Connections using the above-mentioned anisotropic conductive material include connections between flexible printed circuit boards and glass substrates (FOG (Film on Glass)), connections between semiconductor chips and flexible printed circuit boards (COF (Chip on Film)), and semiconductor chips. Examples include connection between a flexible printed circuit board and a glass substrate (COG (Chip on Glass)), and connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)).
  • Patent Document 1 discloses conductive particles comprising base particles and a conductive layer disposed on the surface of the base particles and containing nickel.
  • the conductive layer containing nickel has a melting point of 300° C. or higher.
  • the conductive layer containing nickel is an alloy layer containing nickel and tin, and the average content of tin is 5% by weight or more, based on 100% by weight of the entire conductive layer containing nickel. % by weight or less.
  • Patent Document 2 includes a base material particle and a conductive layer disposed on the surface of the base material particle and containing nickel, and the conductive layer containing nickel is composed of nickel, tin, and indium.
  • Conductive particles are disclosed which are alloy layers containing at least one of the following. In the conductive particles, the total average content of tin and indium is less than 5% by weight in 100% by weight of the region from the outer surface of the nickel-containing conductive layer to 1/2 the thickness inward. .
  • wearable displays In recent years, conductive materials used in wearable displays such as smart watches and smart glasses and various sensors have been attracting attention. Wearable displays are expected to be used continuously for long periods of time in various environments, so the conductive particles and connection structures used in wearable displays must be exposed to high temperature, high humidity, and high voltage for long periods of time. Performance that can withstand even the most extreme conditions is required.
  • connection resistance tends to increase when conductive particles that have been exposed to high temperatures are used, or when a connected structure using conductive particles is exposed to high temperatures.
  • An object of the present invention is to reduce the connection resistance when electrically connecting electrodes, and to maintain the Ni-Sn conductive layer even when exposed to high voltage in a high temperature and high humidity environment for a long time.
  • An object of the present invention is to provide conductive particles that can prevent charge transfer.
  • Another object of the present invention is to provide a conductive material and a connected structure using the above-mentioned conductive particles.
  • the present invention comprises base particles and a Ni--Sn conductive layer containing nickel and tin, and the Ni--Sn conductive layer is disposed on the surface of the base particles,
  • the average tin content in the entire area of the Ni-Sn conductive layer is less than 5% by weight, and when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the Ni -Sn Conductive particles are provided in which the maximum tin content is 5% by weight or more in the outer half-thickness region of the conductive layer.
  • the outer thickness of the Ni-Sn conductive layer is 1/ In the area No. 2, 80% by weight or more of tin is contained out of the total 100% by weight of tin contained in the entire Ni--Sn conductive layer.
  • the thickness of the Ni-Sn conductive layer is 15% or more. In the region, tin is included.
  • the thickness of the Ni-Sn conductive layer is 10% or more and In the region of less than 50%, tin is included in a content of 5% by weight or more.
  • the thickness of the Ni-Sn conductive layer is 10% or more and In the region of less than 50%, tin is contained in a content of 5% by weight or more, and in the region of 1/2 the outer thickness of the Ni-Sn conductive layer, the maximum value of the tin content is 5% by weight. % or more and 40% by weight or less.
  • the thickness of the Ni-Sn conductive layer is 30% or less. In the region, tin is contained in a content of 5% by weight or more.
  • the outer thickness of the Ni-Sn conductive layer is 1/ In region 2, the maximum tin content is 10% by weight or more.
  • the thickness of the Ni-Sn conductive layer is 30% or less.
  • the area contains tin in a content of 5% by weight or more, and the maximum value of the tin content is 10% by weight or more in the area of 1/2 the thickness outside the Ni-Sn conductive layer. .
  • the conductive particles have a particle diameter of 0.1 ⁇ m or more and 1000 ⁇ m or less.
  • the conductive particle has a plurality of protrusions on the outer surface of the Ni—Sn conductive layer.
  • a conductive material that includes the above-described conductive particles and a binder resin.
  • a first connection target member having a first electrode on its surface
  • a second connection target member having a second electrode on its surface
  • the first connection target member and the a connecting portion connecting a second connection target member the connecting portion being formed of the above-mentioned conductive particles, or of a conductive material containing the conductive particles and a binder resin.
  • a connected structure is provided, wherein the first electrode and the second electrode are electrically connected by the conductive particles.
  • the conductive particles according to the present invention include base particles and a Ni—Sn conductive layer containing nickel and tin.
  • the Ni-Sn conductive layer is arranged on the surface of the base particle, and the average tin content in the entire area of the Ni-Sn conductive layer is 5% by weight. less than
  • the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, in the outer half-thickness region of the Ni-Sn conductive layer, The maximum value of tin content is 5% by weight or more.
  • connection resistance can be lowered, and high temperature Furthermore, even when exposed to high voltage for a long time in a high humidity environment, charge movement in the Ni--Sn conductive layer can be prevented.
  • FIG. 1 is a cross-sectional view showing conductive particles according to a first embodiment of the present invention.
  • FIG. 2 is a cross-sectional view showing conductive particles according to a second embodiment of the present invention.
  • FIG. 3 is a cross-sectional view showing conductive particles according to a third embodiment of the present invention.
  • FIG. 4 is a schematic diagram for explaining each region of the Ni--Sn conductive layer in the conductive particles according to the first embodiment of the present invention.
  • FIG. 5 is a cross-sectional view schematically showing a connected structure using conductive particles according to the first embodiment of the present invention.
  • conductive particles Conventionally, when a conductive layer contains nickel, nickel is easily corroded, so when nickel is deposited, the connection resistance between the electrodes tends to increase. Further, when conductive particles containing nickel in the conductive layer are exposed to high voltage in a high temperature and high humidity environment, metal corrosion may occur and charges in the conductive layer may move. As a result, a short circuit may occur or conduction reliability may deteriorate.
  • the present inventor has discovered that even if it contains nickel, it is possible to lower not only the initial connection resistance but also the connection resistance after being exposed to the presence of acid, and that it is conductive in high temperature and high humidity environments.
  • the inventors focused on the content and distribution of tin within the conductive layer.
  • the present inventors have found that the above problem can be solved by controlling the tin content in the entire conductive layer and modifying the distribution of tin in the conductive layer.
  • the conductive particles according to the present invention include base particles and a Ni--Sn conductive layer containing nickel and tin, and the Ni--Sn conductive layer is arranged on the surface of the base particles.
  • the average content of tin in the entire area of the Ni--Sn conductive layer is less than 5% by weight.
  • the maximum value of tin content is 5% by weight or more.
  • connection resistance when electrically connecting electrodes using the conductive particles according to the present invention. Furthermore, connection resistance after exposure to the presence of acid can be reduced. Furthermore, even if the conductive particles are exposed to high voltage (e.g. 15V) for a long time (e.g. 500 hours) in a high temperature (e.g. 85°C) and high humidity (e.g. 85% RH) environment, Ni- Transfer of charges in the Sn conductive layer can be prevented.
  • high voltage e.g. 15V
  • a long time e.g. 500 hours
  • high temperature e.g. 85°C
  • high humidity e.g. 85% RH
  • connection resistance when a connected structure is produced using conductive particles stored in a high temperature and high humidity environment for a long period of time, an increase in connection resistance can be suppressed.
  • the particle diameter of the conductive particles is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, preferably 1000 ⁇ m or less, more preferably 500 ⁇ m or less, still more preferably 100 ⁇ m or less, and particularly preferably 30 ⁇ m or less.
  • the particle diameter of the conductive particles is not less than the lower limit and not more than the upper limit, when the conductive particles are used to connect the electrodes, the contact area between the conductive particles and the electrodes is sufficiently large;
  • agglomerated conductive particles are less likely to be formed when forming a conductive part.
  • the distance between the electrodes connected via the conductive particles does not become too large, and the conductive part becomes difficult to peel off from the surface of the base particle.
  • the particle diameter of the conductive particles mentioned above means the diameter when the conductive particles are true spherical, and when the conductive particles have a shape other than true spherical, it is assumed that the conductive particles are true spheres equivalent to the volume. means the diameter of
  • the particle diameter of the conductive particles is preferably an average particle diameter, and preferably a number average particle diameter.
  • the particle diameter of the above-mentioned conductive particles can be determined, for example, by observing 50 arbitrary conductive particles with an electron microscope or optical microscope and calculating the average value of the particle diameter of each conductive particle, or by using a particle size distribution measuring device. It can be found using In observation using an electron microscope or an optical microscope, the particle diameter of each conductive particle is determined as the particle diameter in equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter of any 50 conductive particles in equivalent circle diameter is approximately equal to the average particle diameter in equivalent sphere diameter. In the particle size distribution measuring device, the particle diameter of each conductive particle is determined as the particle diameter in equivalent sphere diameter.
  • the average particle diameter of the conductive particles is preferably calculated using a particle size distribution measuring device.
  • the coefficient of variation (CV value) of the particle diameter of the conductive particles is preferably 10% or less, more preferably 5% or less.
  • the lower limit of the coefficient of variation of the particle diameter of the conductive particles is not particularly limited.
  • the coefficient of variation of the particle diameter of the conductive particles may be 0%, 0% or more, or 5% or more.
  • CV value The above coefficient of variation (CV value) can be measured as follows.
  • CV value (%) ( ⁇ /Dn) x 100 ⁇ : Standard deviation of particle diameter of conductive particles Dn: Average value of particle diameter of conductive particles
  • the shape of the conductive particles is not particularly limited.
  • the conductive particles may have a spherical shape, a shape other than a spherical shape, a flat shape, or the like.
  • FIG. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention.
  • the conductive particles 1 shown in FIG. 1 have base particles 2 and a Ni—Sn conductive layer 3.
  • Ni—Sn conductive layer 3 contains nickel and tin.
  • the Ni—Sn conductive layer 3 is arranged on the surface of the base particle 2. In the first embodiment, the Ni—Sn conductive layer 3 is in contact with the surface of the base particle 2.
  • the conductive particles 1 are coated particles in which the surface of a base particle 2 is coated with a Ni—Sn conductive layer 3.
  • the Ni—Sn conductive layer 3 is a single-layer conductive layer.
  • the Ni-Sn conductive layer may cover the entire surface of the base particle, or the Ni-Sn conductive layer may cover a part of the surface of the base particle.
  • the conductive particles may have a conductive layer other than the Ni--Sn conductive layer.
  • the conductive particles may have multiple conductive layers.
  • the conductive particles 1 do not have a core substance, unlike the conductive particles 11 and 21 described below.
  • the conductive particles 1 do not have protrusions on the surface.
  • the conductive particles 1 are spherical.
  • the Ni--Sn conductive layer 3 has no protrusions on its outer surface. In this way, the conductive particles according to the present invention do not need to have protrusions on the surface of the Ni--Sn conductive layer, and may be spherical.
  • the conductive particles 1 do not have an insulating substance, unlike conductive particles 11 and 21 described later. However, the conductive particles 1 may have an insulating substance disposed on the outer surface of the Ni--Sn conductive layer 3.
  • the average content of tin in the entire area of the Ni--Sn conductive layer 3 is less than 5% by weight.
  • the tin content in the thickness direction of the Ni-Sn conductive layer 3 is measured by TEM-EDX, it is found that the tin content is found in the outer half-thickness region of the Ni-Sn conductive layer 3.
  • the maximum amount is 5% by weight or more.
  • FIG. 2 is a cross-sectional view showing conductive particles according to the second embodiment of the present invention.
  • the conductive particles 11 shown in FIG. 2 include a base particle 2, a Ni—Sn conductive layer 12, a plurality of core substances 13, and a plurality of insulating substances 14.
  • the Ni—Sn conductive layer 12 is arranged on the surface of the base particle 2 so as to be in contact with the base particle 2.
  • the Ni—Sn conductive layer 12 is a single-layer conductive layer.
  • the Ni-Sn conductive layer may cover the entire surface of the base particle, or the Ni-Sn conductive layer may cover a part of the surface of the base particle.
  • the conductive particles may have a conductive layer other than the Ni--Sn conductive layer.
  • the conductive particles may have multiple conductive layers.
  • the conductive particles 11 have a plurality of protrusions 11a on the surface.
  • the Ni--Sn conductive layer 12 has a plurality of protrusions 12a on its outer surface.
  • a plurality of core substances 13 are arranged on the surface of the base particle 2.
  • a plurality of core materials 13 are embedded within the Ni--Sn conductive layer 12.
  • the core material 13 is arranged inside the protrusions 11a, 12a.
  • a Ni--Sn conductive layer 12 covers a plurality of core materials 13.
  • the outer surface of the Ni--Sn conductive layer 12 is raised by a plurality of core materials 13, and protrusions 11a and 12a are formed.
  • the conductive particles 11 have an insulating material 14 disposed on the outer surface of the Ni--Sn conductive layer 12. At least a portion of the outer surface of the Ni--Sn conductive layer 12 is covered with an insulating material 14.
  • the insulating substance 14 is made of an insulating material and is an insulating particle.
  • the conductive particles according to the present invention may have an insulating material disposed on the outer surface of the Ni--Sn conductive layer.
  • the conductive particles according to the present invention do not necessarily have to contain an insulating substance.
  • the average content of tin in the entire area of the Ni--Sn conductive layer 12 is less than 5% by weight.
  • the tin content in the thickness direction of the Ni-Sn conductive layer 12 is measured by TEM-EDX, it is found that the tin content in the outer half-thickness region of the Ni-Sn conductive layer 12 is The maximum amount is 5% by weight or more.
  • FIG. 3 is a cross-sectional view showing conductive particles according to the third embodiment of the present invention.
  • the conductive particles 21 shown in FIG. 3 include a base particle 2, a Ni--Sn conductive layer 22A (first conductive layer), a plurality of core substances 13, and a plurality of insulating substances 14.
  • the conductive particles 21 have a Ni--Sn conductive layer 22A (first conductive layer) on the side opposite to the base particle 2 side, and a second conductive layer 22B on the base particle 2 side.
  • the only difference between the conductive particles 11 and the conductive particles 21 is the second conductive layer 22B. That is, in the conductive particles 11, a conductive layer having a single layer structure is formed, whereas in the conductive particles 21, a conductive layer having a two layer structure is formed. In the conductive particles 11, a Ni--Sn conductive layer 12 is formed, whereas in the conductive particles 21, a Ni--Sn conductive layer 22A (first conductive layer) and a second conductive layer 22B are formed. ing. In the conductive particles 21, a Ni--Sn conductive layer 22A (first conductive layer) and a second conductive layer 22B are formed as separate conductive layers.
  • the second conductive layer 22B is arranged on the surface of the base particle 2.
  • a second conductive layer 22B is arranged between the base material particles 2 and the Ni--Sn conductive layer 22A (first conductive layer).
  • the second conductive layer 22B is in contact with the base particle 2.
  • the Ni--Sn conductive layer 22A (first conductive layer) is in contact with the second conductive layer 22B. Therefore, the second conductive layer 22B is disposed on the surface of the base particle 2, and the Ni--Sn conductive layer 22A (first conductive layer) is disposed on the surface of the second conductive layer 22B.
  • the conductive particles 21 have a plurality of protrusions 21a on their surfaces.
  • the Ni--Sn conductive layer 22A (first conductive layer) has a plurality of protrusions 22Aa on its outer surface.
  • the second conductive layer 22B has a plurality of protrusions 22Ba on its outer surface.
  • the average tin content in the entire area of the Ni--Sn conductive layer 22A is less than 5% by weight.
  • the tin content in the thickness direction of the Ni-Sn conductive layer 22A is measured by TEM-EDX, it is found that the tin content is found in the outer half-thickness region of the Ni-Sn conductive layer 22A.
  • the maximum amount is 5% by weight or more.
  • the material of the base particles is not particularly limited.
  • the material of the base particles may be an organic material or an inorganic material.
  • Examples of the base material particles formed only from the above-mentioned organic material include resin particles.
  • Examples of the base material particles formed only from the above-mentioned inorganic material include inorganic particles excluding metals.
  • Examples of the base particles formed of both the organic material and the inorganic material include organic-inorganic hybrid particles. From the viewpoint of further improving the compression characteristics of the base particles, the base particles are preferably resin particles or organic-inorganic hybrid particles, and more preferably resin particles.
  • the organic materials mentioned above include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; polycarbonate, polyamide, phenol formaldehyde resin, and melamine.
  • polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene
  • acrylic resins such as polymethyl methacrylate and polymethyl acrylate
  • polycarbonate polyamide, phenol formaldehyde resin, and melamine.
  • Formaldehyde resin benzoguanamine formaldehyde resin, urea formaldehyde resin, phenolic resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, Examples include polyetheretherketone, polyethersulfone, and divinylbenzene polymer.
  • the divinylbenzene polymer may be a divinylbenzene copolymer.
  • the divinylbenzene copolymer and the like examples include divinylbenzene-styrene copolymer and divinylbenzene-(meth)acrylic acid ester copolymer. Since the compression properties of the base particles can be easily controlled within a suitable range, the material of the base particles is a polymer obtained by polymerizing one or more polymerizable monomers having ethylenically unsaturated groups. It is preferable that
  • the polymerizable monomer having an ethylenically unsaturated group includes a non-crosslinkable monomer and a crosslinkable monomer. Examples include monomers with different characteristics.
  • non-crosslinking monomer examples include vinyl compounds such as styrene monomers such as styrene, ⁇ -methylstyrene, and chlorostyrene; vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; vinyl acetate, vinyl butyrate, Acid vinyl ester compounds such as vinyl laurate and vinyl stearate; halogen-containing monomers such as vinyl chloride and vinyl fluoride; (meth)acrylic compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate; ) acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc
  • meth)acrylate compounds oxygen atom-containing (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, glycidyl (meth)acrylate; (meth)acrylonitrile, etc.
  • oxygen atom-containing (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, glycidyl (meth)acrylate; (meth)acrylonitrile, etc.
  • Nitrile-containing monomers such as halogen-containing (meth)acrylate compounds such as trifluoromethyl (meth)acrylate and pentafluoroethyl (meth)acrylate; ⁇ -olefin compounds such as olefins such as diisobutylene, isobutylene, linear alene, ethylene, and propylene Compound: Examples of conjugated diene compounds include isoprene and butadiene.
  • crosslinking monomer examples include vinyl monomers such as divinylbenzene, 1,4-divinyloxybutane, and divinylsulfone as vinyl compounds; tetramethylolmethanetetra(meth)acrylate as (meth)acrylic compounds; , polytetramethylene glycol diacrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate ) acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, 1,4-butan
  • the above-mentioned base material particles can be obtained by polymerizing the above-mentioned polymerizable monomer having an ethylenically unsaturated group.
  • the above polymerization method is not particularly limited, and includes known methods such as radical polymerization, ionic polymerization, polycondensation (condensation polymerization, condensation polymerization), addition condensation, living polymerization, and living radical polymerization.
  • Other polymerization methods include suspension polymerization in the presence of a radical polymerization initiator.
  • examples of the inorganic materials include silica, alumina, barium titanate, zirconia, carbon black, silicate glass, borosilicate glass, lead glass, soda-lime glass, and alumina-silicate glass.
  • the base particles may be organic-inorganic hybrid particles.
  • the base particles may be core-shell particles.
  • examples of the inorganic material of the base particles include silica, alumina, barium titanate, zirconia, and carbon black.
  • the inorganic substance is not a metal.
  • the base particles formed from the silica are not particularly limited, but after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, baking may be performed as necessary. Examples include base material particles obtained by carrying out this method.
  • Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed from a crosslinked alkoxysilyl polymer and an acrylic resin.
  • the organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell disposed on the surface of the core.
  • the core is an organic core.
  • the shell is an inorganic shell.
  • the base particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell disposed on the surface of the organic core.
  • Examples of the material for the organic core include the organic materials described above.
  • the material for the inorganic shell examples include the inorganic substances listed as the material for the base particles described above.
  • the material of the inorganic shell is preferably silica.
  • the inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material by a sol-gel method on the surface of the core, and then firing the shell-like material.
  • the metal alkoxide is a silane alkoxide.
  • the inorganic shell is preferably formed of silane alkoxide.
  • the particle diameter of the base particles is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more.
  • the particle size of the base particles is preferably 1000 ⁇ m or less, more preferably 500 ⁇ m or less, even more preferably 100 ⁇ m or less, particularly preferably 30 ⁇ m or less, and most preferably 10 ⁇ m or less.
  • the particle size of the base material particles is equal to or larger than the lower limit, the contact area between the conductive particles and the electrodes becomes large, which increases the reliability of conduction between the electrodes, and the connection between the conductive particles through the conductive particles increases. The connection resistance between the electrodes can be further reduced.
  • the particle diameter of the base particles is below the above upper limit, the conductive particles are easily compressed, and the connection resistance between the electrodes can be further lowered, and the distance between the electrodes can be further reduced. can.
  • the particle diameter of the base material particle mentioned above indicates the diameter when the base material particle is true spherical, and when the base material particle has a shape other than true spherical shape, it is assumed that the base material particle is a true sphere equivalent to the volume. means the diameter of
  • the particle diameter of the above-mentioned base material particles indicates the number average particle diameter.
  • the particle diameter of the above-mentioned base material particles can be determined by observing 50 arbitrary base material particles with an electron microscope or optical microscope and calculating the average value of the particle diameter of each base material particle, or by using a particle size distribution measuring device. Desired. In observation using an electron microscope or an optical microscope, the particle diameter of each base particle is determined as the particle diameter in equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter of any 50 base particles in equivalent circle diameter is approximately equal to the average particle diameter in equivalent sphere diameter. In the particle size distribution measuring device, the particle diameter of each base material particle is determined as the particle diameter in equivalent sphere diameter.
  • the average particle diameter of the base particles is preferably calculated using a particle size distribution measuring device.
  • the particle diameter of the base particle in the conductive particles for example, it can be measured as follows.
  • a conductive particle content of 30% by weight is added to "Technovit 4000" manufactured by Kulzer and dispersed to prepare an embedded resin body for conductive particle inspection.
  • IM4000 manufactured by Hitachi High-Technologies
  • a cross section of the conductive particles is cut out so as to pass through the center of the base particle of the conductive particles dispersed in the embedded resin body for inspection.
  • FE-SEM field emission scanning electron microscope
  • the image magnification was set to 25,000 times, 50 conductive particles were randomly selected, and the base material particles of each conductive particle were observed. do.
  • the particle diameter of the base material particle in each conductive particle is measured, and the arithmetic average of the measurements is taken as the particle diameter of the base material particle.
  • the conductive particles include a Ni--Sn conductive layer containing nickel and tin.
  • the average tin content in the entire area of the Ni--Sn conductive layer is less than 5% by weight.
  • the conductive particles when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, in the outer half-thickness region (R1) of the Ni-Sn conductive layer, The maximum value of tin content is 5% by weight or more.
  • the region R1 is a region having a thickness of 50% outside the Ni--Sn conductive layer.
  • FIG. 4 is a schematic diagram for explaining each region of the Ni—Sn conductive layer in the conductive particles according to the first embodiment of the present invention.
  • FIG. 4 is a schematic diagram for explaining each region of the Ni—Sn conductive layer 3 in the conductive particle 1. As shown in FIG.
  • the outer 1/2 thickness region (R1) of the Ni-Sn conductive layer is a region extending from the outer surface of the Ni-Sn conductive layer inward to 1/2 the thickness of the Ni-Sn conductive layer. .
  • the region R1 is the region outside the broken line L1 of the Ni—Sn conductive layer 3 in FIG.
  • the region R1 is the outer surface portion of the Ni—Sn conductive layer 3.
  • the region R1 is a region different from the region of the Ni—Sn conductive layer 3 on the base particle 2 side.
  • the inner 1/2 thickness region (R2) of the Ni-Sn conductive layer is a region extending from the inner surface of the Ni-Sn conductive layer toward the outside to 1/2 the thickness of the Ni-Sn conductive layer. .
  • the region R2 is a region inside the broken line L1 of the Ni--Sn conductive layer 3 in FIG.
  • the region R2 is a region of the Ni—Sn conductive layer 3 on the base particle 2 side.
  • the region R2 is a region different from the outer surface portion of the Ni—Sn conductive layer 3.
  • the average content of tin in the entire area of the Ni—Sn conductive layer is less than 5% by weight. Since the conductive particles have the above configuration, the initial resistance can be lowered. From the viewpoint of further lowering the initial resistance, the average tin content in the entire area of the Ni-Sn conductive layer is preferably 4.5% by weight or less, more preferably 4.0% by weight or less, and even more preferably is 3.5% by weight or less. From the viewpoint of further lowering the connection resistance after being exposed to the presence of an acid, the average content of tin in the entire area of the Ni--Sn conductive layer exceeds 0% by weight, preferably 0.1% by weight. It is at least 0.5% by weight, more preferably at least 0.5% by weight.
  • the Ni—Sn layer preferably contains nickel as a main metal.
  • the average content of nickel in the entire area of the Ni--Sn conductive layer is preferably 50% by weight or more, more preferably 80% by weight or more, and preferably 99.9% by weight or less, more preferably 99.5% by weight. % by weight or less.
  • the average content of nickel and tin in the entire area of the Ni--Sn conductive layer can be measured by ICP-MS method or the like.
  • the conductive particles when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, in the outer half-thickness region (R1) of the Ni-Sn conductive layer, The maximum value of tin content is 5% by weight or more. Since the conductive particles have the above-described structure, it is possible to prevent charge movement in the Ni--Sn conductive layer even when exposed to high voltage for a long time in a high temperature and high humidity environment.
  • the maximum value of the tin content of the Ni-Sn conductive layer is in the region R1.
  • the maximum tin content in the entire region of the Ni—Sn conductive layer exists in the region R1.
  • the region where the tin content has the maximum value in the entire region of the Ni—Sn conductive layer is the region R1.
  • the tin content preferably reaches a maximum value in the region R1.
  • the maximum tin content in the region R1 is the tin content in the region R2.
  • the amount is greater than the maximum value.
  • the maximum value of the tin content in the Ni-Sn conductive layer is in the region R1. The maximum tin content is preferred.
  • tin is unevenly distributed in the thickness direction of the Ni--Sn conductive layer. In the conductive particles, tin is unevenly distributed in the thickness direction of the Ni--Sn conductive layer.
  • the conductive particles preferably have different tin contents such that the tin content in the region R1 is higher than the tin content in the region R2 in the Ni—Sn conductive layer. It is preferable that the content has a gradient. In the Ni--Sn conductive layer, it is preferable that tin is unevenly distributed so that it is present more in the region R1 than in the region R2. In the Ni—Sn conductive layer, the average tin content in the region R1 is preferably larger than the average tin content in the region R2. The presence of such a concentration difference and concentration gradient can further reduce the connection resistance after exposure to the presence of acid, and the conductive particles can be exposed to high voltage for a long time in a hot and humid environment. Even if exposed to the Ni--Sn conductive layer, movement of charges in the Ni--Sn conductive layer can be more effectively prevented.
  • the average content of tin in the region R1 is preferably 0.5% by weight or more, more preferably 1% by weight, based on 100% by weight of the entire region R1.
  • the content is at least .0% by weight, more preferably at least 3.0% by weight, preferably at most 10% by weight, more preferably at most 9.0% by weight, even more preferably at most 8.0% by weight.
  • the average content of tin in the region R2 is preferably 10% by weight or less, more preferably 5% by weight, based on the entire 100% by weight of the region R2.
  • the content is preferably 3% by weight or less.
  • the lower limit of the average content of tin in the region R2 in 100% by weight of the entire region R2 is not particularly limited.
  • the average content of tin in the region R2 may be 3% by weight or more out of 100% by weight of the entire region R2.
  • the conductive particles according to the present invention it is very important to control the distribution of tin contained in the Ni--Sn conductive layer in the thickness direction.
  • the content of tin in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the content of tin in the region R1 is out of the total 100% by weight of tin contained in the entire Ni-Sn conductive layer.
  • the amount is preferably 65% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more.
  • the 1/2 region (R1) contains 80% by weight or more of tin out of the total 100% by weight of tin contained in the entire Ni--Sn conductive layer.
  • the content of tin in the region R1 is more preferably 85% by weight or more, even more preferably 90% by weight or more, particularly preferably 95% by weight or more, out of the total 100% by weight of tin contained in the entire Ni--Sn conductive layer. % by weight or more, most preferably 100% by weight (total amount).
  • the content of tin in the region R1 is equal to or higher than the lower limit of the total 100% by weight of tin contained in the entire Ni-Sn conductive layer, the connection resistance after being exposed to the presence of an acid will be increased. Even if the conductive particles are exposed to high voltage for a long time in a high temperature and high humidity environment, the transfer of charges in the Ni--Sn conductive layer can be even more effectively prevented.
  • the proportion of the area containing tin in 100% of the thickness of the Ni--Sn conductive layer is preferably 5% or more, more preferably is 15% or more, preferably 95% or less, more preferably 80% or less, even more preferably 50% or less.
  • the Ni-Sn when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the Ni-Sn Preferably, tin is contained in a region where the conductive layer has a thickness of 15% or more.
  • the proportion of the area containing tin in 100% of the thickness of the conductive layer is about 10%.
  • the proportion of the area containing tin in 100% of the thickness of the Ni-Sn conductive layer is equal to or more than the above-mentioned lower limit and below the above-mentioned upper limit, the connection after being exposed to the presence of acid is The resistance can be lowered even further, and even if the conductive particles are exposed to high voltage for a long time in a high temperature and high humidity environment, the transfer of charge in the Ni-Sn conductive layer can be more effectively prevented. can.
  • the thickness of the area containing tin peak width in the distribution curve
  • the area It is very important to control the relationship between the maximum value of tin content (peak height in the distribution curve) and the maximum tin content (peak height in the distribution curve). That is, in the conductive particles, in the tin content distribution curve measured by TEM-EDX, the distance in the thickness direction from the outer surface when the horizontal axis is the thickness of the Ni-Sn conductive layer as 100% ( %) and the vertical axis is the tin content (weight %), it is very important to control the peak width and peak height of the distribution curve.
  • the shape of the tin content distribution curve may be a mountain shape or a portion of a mountain shape.
  • the tin content distribution curve may be unimodal or multimodal.
  • the tin content distribution curve may have one peak or a plurality of peaks.
  • the proportion of the area containing tin in 100% of the thickness of the Ni--Sn conductive layer is the sum of the widths of each peak.
  • the distribution curve of the tin content preferably has one peak, and as described above, the peak (the maximum value of the tin content of the Ni--Sn conductive layer) is present in the region R1. It is preferred that the Ni--Sn conductive layer be present on the outermost surface of the Ni--Sn conductive layer.
  • the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, it is found that tin is distributed over a wide area in the thickness direction of the Ni-Sn conductive layer, and The maximum value of the tin content in the Ni--Sn conductive layer may be small.
  • the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, it is found that tin is distributed over a wide area in the thickness direction of the Ni-Sn conductive layer, and In the outer half-thickness region (R1) of the Ni—Sn conductive layer, the maximum value of the tin content may be small.
  • the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX
  • tin is distributed in a narrow region in the thickness direction of the Ni-Sn conductive layer
  • the maximum value of the tin content may be large.
  • the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX
  • tin is distributed in a narrow region in the thickness direction of the Ni-Sn conductive layer, and In the outer half-thickness region (R1) of the Ni—Sn conductive layer, the maximum value of the tin content may be large.
  • the proportion of the area containing tin in the 100% thickness of the Ni--Sn conductive layer is particularly preferably 20% or more, most preferably 25% or more. Further, in the above case, the proportion of the area containing tin in the 100% thickness of the Ni--Sn conductive layer is particularly preferably 50% or less, most preferably 40% or less. In the above case, the tin content in the thickness direction of the Ni--Sn conductive layer is measured by TEM-EDX.
  • tin is contained in a content of 5% by weight or more in a region where the thickness of the Ni--Sn conductive layer is 10% or more and less than 50%.
  • the area where the tin content is 5% by weight or more is preferably 8% or more, more preferably 10% or more, and even more preferably 12.5% of the 100% thickness of the Ni-Sn conductive layer. % or more, preferably less than 50%, more preferably 40% or less, even more preferably 30% or less.
  • the tin content in the thickness direction of the Ni--Sn conductive layer is measured by TEM-EDX.
  • the maximum tin content in the outer 1/2 thickness region (R1) of the Ni-Sn conductive layer is 5% by weight or more, preferably 7% by weight or more, more preferably 10% by weight. % or more, preferably 50% by weight or less, more preferably 40% by weight or less, still more preferably 30% by weight or less, particularly preferably 20% by weight or less.
  • tin is contained at a content of 5% by weight or more in a region where the thickness of the Ni-Sn conductive layer is 10% or more and less than 50%, and the thickness of the Ni-Sn conductive layer is In the outer half-thickness region (R1), the maximum tin content is more preferably 5% by weight or more and 40% by weight or less.
  • the proportion of the area containing tin in the 100% thickness of the Ni--Sn conductive layer is particularly preferably 5% or more, most preferably 10% or more.
  • the proportion of the area containing tin in the 100% thickness of the Ni--Sn conductive layer is more preferably 40% or less, particularly preferably 30% or less, and most preferably 25% or less.
  • the tin content in the thickness direction of the Ni--Sn conductive layer is measured by TEM-EDX.
  • tin is contained in a content of 5% by weight or more in a region where the thickness of the Ni--Sn conductive layer is 30% or less.
  • the area where the tin content is 5% by weight or more is preferably 0.1% or more, more preferably 0.5% or more, and even more preferably is 1.0% or more, preferably 30% or less, more preferably 25% or less, even more preferably 20% or less, and most preferably 10% or less.
  • the tin content in the thickness direction of the Ni--Sn conductive layer is measured by TEM-EDX.
  • the maximum tin content in the outer 1/2 thickness region (R1) of the Ni-Sn conductive layer is 5% by weight or more, preferably 10% by weight or more, and more preferably 15% by weight. % or more.
  • the maximum value of the tin content is preferably 95% by weight or less, more preferably 90% by weight or less, It is more preferably 80% by weight or less, particularly preferably 50% by weight or less, most preferably 40% by weight or less.
  • the tin content is 5% by weight or more in the area where the thickness of the Ni-Sn conductive layer is 30% or less, and the tin content is 5% by weight or more in the area where the thickness of the Ni-Sn conductive layer is 1/2 In region (R1), the maximum tin content is more preferably 10% by weight or more.
  • the average content of nickel and tin in the region R1, the average content of nickel and tin in the region R2, the maximum value of the tin content in the region R1, and the maximum value of the tin content in the region R2 are as follows: It can be measured by TEM-EDX. Specifically, a thin film section of the conductive particles is produced using a focused ion beam. Next, using a transmission electron microscope FE-TEM ("JEM-2010FEF" manufactured by JEOL Ltd.) and an energy dispersive X-ray spectrometer (EDS), each of nickel and tin was measured in the thickness direction of the Ni-Sn conductive layer. Measure the content.
  • the outermost inflection point on the curve showing the content of all metals contained in the Ni-Sn conductive layer is The starting point (thickness 0%) is taken as the innermost inflection point and the end point (thickness 100%) in the thickness direction of the Ni--Sn conductive layer.
  • the Ni—Sn conductive layer may contain nickel, tin, and a metal other than nickel and tin.
  • Metals other than nickel and tin include silver, copper, platinum, zinc, iron, lead, aluminum, cobalt, indium, palladium, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, silicon, tungsten, molybdenum, and Examples include tin-doped indium oxide (ITO). These metals may be used alone or in combination of two or more.
  • the average content of metals other than nickel and tin in the entire area of the Ni--Sn conductive layer is preferably 10% by weight or less, more preferably 5% by weight or less, and even more preferably 3% by weight or less.
  • the lower limit of the average content of metals other than nickel and tin in the entire area of the Ni--Sn conductive layer is not particularly limited.
  • the average content of the metal other than nickel and tin in the entire area of the Ni--Sn conductive layer may be 0.01% by weight or more, or 0.1% by weight or more.
  • the Ni-Sn conductive layer contains a metal other than the nickel and tin
  • the average nickel content and the average tin content in the region R1 and the region R2 are the same as the nickel content and the tin content.
  • the total amount including the content is calculated as 100% by weight.
  • the thickness of the Ni--Sn conductive layer is preferably 5 nm or more, more preferably 10 nm or more, even more preferably 80 nm or more, and preferably 500 nm or less, more preferably 300 nm or less.
  • the thickness of the Ni--Sn conductive layer mentioned above indicates the average thickness of the Ni--Sn conductive layer in the conductive particles.
  • the method for forming the Ni--Sn conductive layer is not particularly limited.
  • Methods for forming the Ni-Sn conductive layer include, for example, electroless plating, electroplating, physical vapor deposition, and coating the surfaces of particles with metal powder or a paste containing metal powder and a binder. Examples include a method to do so. Among these, a method using electroless plating is preferred because the formation of the Ni--Sn conductive layer is simple.
  • Examples of the physical vapor deposition method include vacuum vapor deposition, ion plating, and ion sputtering.
  • Methods for controlling the content and distribution of nickel and tin in the Ni-Sn conductive layer include, for example, a method of adjusting the concentration of tin and a complexing agent in the plating solution in electroless plating, and a method of controlling the concentration of tin and complexing agent in the plating solution, and Examples include a method of adjusting pH.
  • the above-mentioned conductive particles may include multiple conductive layers.
  • the conductive particles may include a conductive layer (another conductive layer) other than the Ni—Sn conductive layer.
  • the Ni—Sn conductive layer is preferably the outermost layer of the conductive particles.
  • the Ni—Sn conductive layer is preferably the outermost conductive layer.
  • the structure of the conductive layers other than the Ni--Sn conductive layer is not particularly limited.
  • the material of the conductive layers other than the Ni--Sn conductive layer may be the same as or different from the material of the Ni--Sn conductive layer.
  • the conductive particles according to the present invention preferably have protrusions on the surface.
  • the Ni--Sn conductive layer preferably has protrusions on its outer surface.
  • An oxide film is often formed on the surface of an electrode connected by conductive particles.
  • the conductive particles have an insulating substance on their surface, or when the conductive particles are dispersed in a resin and used as a conductive material, the protrusions of the conductive particles create a gap between the conductive particles and the electrode. Insulating materials or resins can be effectively eliminated. Therefore, the reliability of conduction between the electrodes can be improved.
  • the number of the protrusions is plural.
  • the number of protrusions on the outer surface of the conductive layer per conductive particle is preferably 3 or more, more preferably 5 or more.
  • the upper limit of the number of projections is not particularly limited.
  • the number of the protrusions is preferably 1000 or less, more preferably 800 or less.
  • the upper limit of the number of protrusions can be appropriately selected in consideration of the particle diameter of the conductive particles, etc.
  • the average height of the plurality of protrusions is preferably 0.001 ⁇ m or more, more preferably 0.05 ⁇ m or more, preferably 0.9 ⁇ m or less, and more preferably 0.2 ⁇ m or less.
  • the average height of the protrusions can be calculated by the following method. Fifty conductive particles of the present invention are observed using an electron microscope or an optical microscope, and the heights of all the protrusions on the periphery of the observed conductive particles are measured. It is determined by measuring the height of the convex portion using a surface on which no protrusions are formed as a reference surface, and calculating the average value.
  • the surface area of the portion with the protrusions is preferably 10% or more, more preferably 20% of the total surface area of the outer surface of the Ni-Sn conductive layer. % or more, more preferably 30% or more.
  • the upper limit of the ratio of the surface area of the portion with the protrusions to 100% of the total surface area of the outer surface of the Ni--Sn conductive layer is not particularly limited, but is usually 100% or less, preferably 99% or less.
  • the ratio of the surface area of the portion where the protrusion is present can be calculated by the following method. It is determined by observing 50 conductive particles of the present invention with an electron microscope or an optical microscope, measuring the ratio of the areas of the portions appearing as protrusions in the orthogonal projection plane, and calculating the average value.
  • the core material Since the core material is embedded in the Ni--Sn conductive layer, it is easy to make the Ni--Sn conductive layer have a plurality of protrusions on its outer surface. However, in order to form protrusions on the outer surfaces of the conductive particles and the Ni--Sn conductive layer, it is not necessary to use a core material, and it is preferable not to use a core material.
  • the conductive particles do not have a core material inside and inside the Ni--Sn conductive layer for raising the outer surface of the Ni--Sn conductive part.
  • the Ni--Sn conductive layer does not include a core material inside and inside the Ni--Sn conductive layer for raising the outer surface of the Ni--Sn conductive layer.
  • the above protrusions can be formed by attaching a core substance to the surface of the base particle and then forming a Ni-Sn conductive layer by electroless plating, or by electroless plating the Ni-Sn conductive layer on the surface of the base particle.
  • Examples include a method of forming a Sn conductive layer, then depositing a core material, and further forming a Ni--Sn conductive layer by electroless plating.
  • Other methods for forming the protrusions include a method of adding a core material during the formation of the Ni--Sn conductive layer on the surface of the base material particles.
  • the core material is added to a dispersion of the base material particles, and the core material is applied to the surface of the base material particles by, for example, van der Waals force.
  • methods of accumulating and adhering the base particles, and methods of adding a core substance to a container containing the base particles and attaching the core substance to the surface of the base particles through mechanical action such as rotation of the container. a method of accumulating and depositing the core material on the surface of the base particles in the dispersion is preferred because it is easy to control the amount of the core material to be deposited.
  • Examples of the substance constituting the core substance include conductive substances and non-conductive substances.
  • Examples of the conductive substance include metals, metal oxides, conductive nonmetals such as graphite, and conductive polymers.
  • Examples of the conductive polymer include polyacetylene.
  • Examples of the non-conductive substance include silica, alumina, barium titanate, and zirconia. Among these, metal is preferred because it can improve conductivity and effectively lower connection resistance.
  • the core material is a metal particle.
  • Examples of the above metals include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, and cadmium, and tin-lead.
  • Examples include alloys composed of two or more metals, such as alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and tungsten carbide. Among them, nickel, copper, silver or gold is preferred.
  • the metal for forming the core material may be the same as or different from the metal for forming the conductive layer.
  • the metal for forming the core material preferably includes the metal for forming the conductive layer.
  • the metal for forming the core material preferably contains nickel.
  • the materials for the core substance include barium titanate (Mohs hardness 4.5), nickel (Mohs hardness 5), silica (silicon dioxide, Mohs hardness 6-7), titanium oxide (Mohs hardness 7), zirconia (Mohs hardness: 8 to 9), alumina (Mohs hardness: 9), tungsten carbide (Mohs hardness: 9), and diamond (Mohs hardness: 10).
  • the inorganic particles are preferably nickel, silica, titanium oxide, zirconia, alumina, tungsten carbide, or diamond, and more preferably silica, titanium oxide, zirconia, alumina, tungsten carbide, or diamond.
  • the inorganic particles are more preferably titanium oxide, zirconia, alumina, tungsten carbide, or diamond, and particularly preferably zirconia, alumina, tungsten carbide, or diamond.
  • the Mohs hardness of the material of the core substance is preferably 5 or more, more preferably 6 or more, still more preferably 7 or more, particularly preferably 7.5 or more.
  • the shape of the core material is not particularly limited.
  • the shape of the core material is preferably a block.
  • Examples of the core substance include particulate lumps, aggregates of a plurality of microparticles, and irregularly shaped lumps.
  • the average diameter (average particle diameter) of the core material is preferably 0.001 ⁇ m or more, more preferably 0.05 ⁇ m or more, preferably 0.9 ⁇ m or less, and more preferably 0.2 ⁇ m or less.
  • the average diameter of the core substance is not less than the above lower limit and not more than the above upper limit, the connection resistance between the electrodes is effectively reduced.
  • the "average diameter (average particle diameter)" of the above-mentioned core substance indicates the number average diameter (number average particle diameter).
  • the average diameter of the core substance can be determined, for example, by observing 50 arbitrary core substances with an electron microscope or an optical microscope and calculating the average value.
  • the conductive particles according to the present invention preferably include an insulating material disposed on the outer surface of the Ni--Sn conductive layer.
  • an insulating material disposed on the outer surface of the Ni--Sn conductive layer.
  • the insulating substance is preferably insulating particles, since the insulating substance can be more easily removed during crimping between the electrodes.
  • thermoplastic resin examples include vinyl polymers and vinyl copolymers.
  • thermosetting resin examples include epoxy resin, phenol resin, and melamine resin.
  • water-soluble resin examples include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, and methylcellulose.
  • the insulating resin preferably contains a water-soluble resin, and more preferably contains polyvinyl alcohol.
  • Examples of methods for disposing an insulating substance on the surface of the Ni—Sn conductive layer include chemical methods, physical or mechanical methods, and the like.
  • Examples of the chemical methods include interfacial polymerization, suspension polymerization in the presence of particles, and emulsion polymerization.
  • Examples of the physical or mechanical methods include spray drying, hybridization, electrostatic adhesion, spraying, dipping, and vacuum deposition. Among these, a method in which the insulating substance is disposed on the surface of the conductive layer via a chemical bond is preferred because the insulating substance is difficult to detach.
  • the outer surface of the Ni—Sn conductive layer and the surface of the insulating particles may each be coated with a compound having a reactive functional group.
  • the outer surface of the conductive layer and the surface of the insulating particles may not be directly chemically bonded to each other, but may be indirectly chemically bonded to each other through a compound having a reactive functional group.
  • the carboxyl group may be chemically bonded to a functional group on the surface of the insulating particle via a polymer electrolyte such as polyethyleneimine.
  • the average diameter (average particle diameter) of the above-mentioned insulating substance can be appropriately selected depending on the particle diameter of the conductive particles, the use of the conductive particles, etc.
  • the average diameter (average particle diameter) of the insulating substance is preferably 0.005 ⁇ m or more, more preferably 0.01 ⁇ m or more, preferably 1 ⁇ m or less, and more preferably 0.5 ⁇ m or less.
  • the average diameter of the insulating substance is equal to or larger than the above lower limit, when the conductive particles are dispersed in the binder resin, the conductive layers of the plurality of conductive particles are difficult to come into contact with each other.
  • the "average diameter (average particle diameter)" of the above-mentioned insulating substance indicates the number average diameter (number average particle diameter).
  • the average diameter of the insulating substance is determined using a particle size distribution measuring device or the like.
  • the electrically conductive material according to the present invention includes the above-mentioned electrically conductive particles and a binder resin.
  • the conductive particles are preferably used as a conductive material by being dispersed in a binder resin, and preferably used as a conductive material by being dispersed in a binder resin.
  • the conductive material is an anisotropic conductive material.
  • the conductive material is preferably used for electrical connection between electrodes.
  • the conductive material is a circuit connection material.
  • the above binder resin is not particularly limited.
  • As the binder resin a known insulating resin is used.
  • binder resin examples include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. Only one type of the binder resin may be used, or two or more types may be used in combination.
  • the vinyl resin examples include vinyl acetate resin, acrylic resin, and styrene resin.
  • the thermoplastic resin examples include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins.
  • the curable resin examples include epoxy resin, urethane resin, polyimide resin, and unsaturated polyester resin. Note that the curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The above-mentioned curable resin may be used in combination with a curing agent.
  • thermoplastic block copolymers examples include styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, hydrogenated products of styrene-butadiene-styrene block copolymers, and styrene-isoprene block copolymers.
  • examples include hydrogenated products of styrene block copolymers.
  • the elastomer examples include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.
  • the conductive materials include, for example, fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, heat stabilizers, and light stabilizers. It may contain various additives such as a UV absorber, a lubricant, an antistatic agent, and a flame retardant.
  • the conductive material according to the present invention can be used as a conductive paste, a conductive film, and the like.
  • the conductive material according to the present invention is a conductive film
  • a film not containing conductive particles may be laminated on a conductive film containing conductive particles.
  • the conductive paste is preferably an anisotropic conductive paste.
  • the conductive film is preferably an anisotropic conductive film.
  • the content of the binder resin in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, particularly preferably 70% by weight or more, and preferably 99% by weight or more. It is 99% by weight or less, more preferably 99.9% by weight or less.
  • the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target members connected by the conductive material becomes even higher.
  • the content of the conductive particles in 100% by weight of the conductive material is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 40% by weight or less, and more preferably 20% by weight or less. , more preferably 10% by weight or less.
  • the content of the conductive particles is at least the above lower limit and at most the above upper limit, the reliability of conduction between the electrodes becomes even higher.
  • connection structure can be obtained by connecting members to be connected using the conductive particles or using a conductive material containing the conductive particles and a binder resin.
  • the connection structure includes a first connection target member, a second connection target member, and a connection part connecting the first and second connection target members, and the connection part has the above-mentioned conductive property.
  • the connected structure be formed of particles or a conductive material containing the above-mentioned conductive particles and a binder resin.
  • the first electrode and the second electrode are electrically connected by the conductive particles described above. If conductive particles are used, the connection itself is the conductive particle. That is, the first and second connection target members are connected by the conductive particles.
  • FIG. 5 schematically shows a cross-sectional view of a connected structure using conductive particles according to the first embodiment of the present invention.
  • connection structure 51 shown in FIG. 5 connects a first connection target member 52, a second connection target member 53, and a connection part 54 connecting the first and second connection target members 52 and 53. Be prepared.
  • the connecting portion 54 is formed by curing a conductive material containing the conductive particles 1. Note that in FIG. 5, the conductive particles 1 are shown schematically for convenience of illustration. In place of the conductive particles 1, conductive particles 11, 21, etc. may be used.
  • the first connection target member 52 has a plurality of first electrodes 52a on its surface (upper surface).
  • the second connection target member 53 has a plurality of second electrodes 53a on the front surface (lower surface).
  • the first electrode 52a and the second electrode 53a are electrically connected by one or more conductive particles 1. Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1.
  • the method for manufacturing the above-mentioned connected structure is not particularly limited.
  • the conductive material is placed between a first member to be connected and a second member to be connected, a laminate is obtained, and then the laminate is heated and pressurized. Examples include methods.
  • the pressure of the above pressurization is about 9.8 ⁇ 10 4 Pa to 4.9 ⁇ 10 6 Pa.
  • the heating temperature is about 120°C to 220°C.
  • connection target members include electronic components such as semiconductor chips, electronic components such as capacitors and diodes, and circuit boards such as printed circuit boards, flexible printed circuit boards, glass epoxy boards, and glass substrates. It is preferable that the member to be connected is an electronic component.
  • the conductive particles are preferably used for electrical connection of electrodes in electronic components.
  • the electrodes provided on the connection target member include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, silver electrodes, molybdenum electrodes, and tungsten electrodes.
  • the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode.
  • the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode.
  • the said electrode when the said electrode is an aluminum electrode, it may be an electrode formed only with aluminum, and the electrode may be an electrode in which an aluminum layer is laminated
  • the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal elements include Sn, Al, and Ga.
  • Base particle A divinylbenzene copolymer resin particles with a particle size of 3.0 ⁇ m (“Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.)
  • Base material particle B Base material particle that differs from base material particle A only in particle size and has a particle size of 2.5 ⁇ m.
  • Base material particle C Only differs from base material particle A in particle size and has a particle size of 10.0 ⁇ m.
  • Base material particle D Core-shell type organic-inorganic hybrid particle with a particle diameter of 3.0 ⁇ m (produced according to Synthesis Example 1 below)
  • Base particle E organic-inorganic hybrid particle having a particle diameter of 3.0 ⁇ m (produced according to Synthesis Example 2 below)
  • the base material particles E were obtained by baking at 350° C. for 2 hours.
  • Example 1 After dispersing 10 parts by weight of the above base material particles A in 100 parts by weight of an alkaline solution containing 5% by weight of palladium catalyst liquid using an ultrasonic disperser, the base material particles A were taken out by filtering the solution. . Next, the base particles A were added to 100 parts by weight of a 1% by weight dimethylamine borane solution to activate the surfaces of the base particles A. After thoroughly washing the surface-activated base material particles A with water, they were added to 500 parts by weight of distilled water and dispersed to obtain a suspension (0).
  • a nickel plating solution (1) (pH 8.5) containing 0.14 mol/L of nickel sulfate, 0.46 mol/L of dimethylamine borane, and 0.2 mol/L of sodium citrate was prepared. While stirring the suspension (0) at 60°C, the nickel plating solution (1) was gradually dropped into the suspension (0) to perform electroless nickel-boron alloy plating. 1) was obtained.
  • a nickel plating solution (2) (pH 8.0) containing 0.14 mol/L of nickel sulfate and 0.45 mol/L of hydrazine was prepared. While stirring the suspension (1) at 65°C, the nickel plating solution (2) was gradually dropped into the suspension (1) to perform electroless nickel plating, and the suspension (2) Obtained.
  • a nickel plating solution (3) (pH 8.0) containing 0.14 mol/L of nickel sulfate, 0.09 mol/L of sodium stannate trihydrate, and 0.45 mol/L of sodium gluconate was prepared. While stirring the suspension (2) at 65°C, the nickel plating solution (3) was gradually dropped into the suspension (2) to perform electroless nickel-tin alloy plating, and the suspension ( 3) was obtained.
  • the particles are taken out by filtering the suspension (3), washed with water, and dried to form conductive particles with a Ni-Sn conductive layer (thickness 136 nm) arranged on the surface of the base particle A. I got it.
  • Example 2 A nickel plating solution (pH 8.0) containing 0.07 mol/L of nickel sulfate, 0.045 mol/L of sodium stannate trihydrate, and 0.225 mol/L of sodium gluconate was prepared. Conductive particles were obtained in the same manner as in Example 1, except that this nickel plating solution was used instead of nickel plating solution (3).
  • Example 3 Conductive particles were obtained in the same manner as in Example 1, except that the nickel plating solution (2) and the nickel plating solution (3) were simultaneously dropped into the suspension (1).
  • Example 4 Conductive particles were deposited in the same manner as in Example 1, except that the nickel plating solution (1), the nickel plating solution (2), and the nickel plating solution (3) were simultaneously dropped into the suspension (0). I got it.
  • Example 5 The pH of the nickel plating solution (1), the nickel plating solution (2) was changed to 8.5, and the pH of the nickel plating solution (3) was changed to 8.5 to the suspension (0). Conductive particles were obtained in the same manner as in Example 1, except that a changed nickel plating solution was dropped at the same time.
  • Example 6 Conductive particles were obtained in the same manner as in Example 1, except that the dropping amounts of the nickel plating solution (1), the nickel plating solution (2), and the nickel plating solution (3) were increased by 1.3 times. .
  • Example 7 Conductive particles were obtained in the same manner as in Example 1, except that the dropping amounts of the nickel plating solution (1), the nickel plating solution (2), and the nickel plating solution (3) were increased by 0.8 times. .
  • Example 8 The concentration of sodium stannate trihydrate in the nickel plating solution (3) was changed from 0.09 mol/L to 0.15 mol/L, and the concentration of sodium gluconate was changed from 0.45 mol/L to 0.75 mol/L. A nickel plating solution changed to L was prepared. Conductive particles were obtained in the same manner as in Example 1, except that this nickel plating solution was used instead of nickel plating solution (3).
  • Example 9 The concentration of sodium stannate trihydrate in the nickel plating solution (3) was changed from 0.09 mol/L to 0.30 mol/L, and the concentration of sodium gluconate was changed from 0.45 mol/L to 0.90 mol/L.
  • a nickel plating solution was prepared using a modified nickel plating solution. Conductive particles were obtained in the same manner as in Example 1, except that this nickel plating solution was used instead of nickel plating solution (3).
  • Example 10 2 g of Ni particle slurry (average particle diameter: 150 nm) was added to the above suspension (0) over 3 minutes to obtain a suspension containing base particles to which the core material was attached.
  • Conductive particles were obtained in the same manner as in Example 1, except that the obtained suspension was used. Protrusions were formed on the outer surface of the Ni--Sn conductive layer of the obtained conductive particles.
  • Example 11 0.5 g of alumina particle slurry (average particle diameter: 150 nm) was added to the suspension (0) over 3 minutes to obtain a suspension containing base particles to which the core material was attached. Conductive particles were obtained in the same manner as in Example 1, except that the obtained suspension was used. Protrusions were formed on the outer surface of the Ni--Sn conductive layer of the obtained conductive particles.
  • Example 12 Protrusions were formed in the above suspension (0) without using Ni particle slurry by adjusting the amount of precipitation to be partially changed during formation of the conductive part, and protrusions were formed on the outer surface of the Ni-Sn conductive layer. Conductive particles were obtained in the same manner as in Example 1, except that .
  • Example 13 to 16 Conductive particles were obtained in the same manner as in Example 10, except that the base particles were changed as shown in Table 3 below. Protrusions were formed on the outer surface of the Ni--Sn conductive layer of the obtained conductive particles.
  • Example 17 (1) Preparation of insulating particles A 1000 mL separable flask equipped with a four-necked separable cover, a stirring blade, a three-way cock, a cooling tube, and a temperature probe was prepared. Into the separable flask, 100 mmol of methyl methacrylate, 1 mmol of N,N,N-trimethyl-N-2-methacryloyloxyethylammonium chloride, and 1 mmol of 2,2'-azobis(2-amidinopropane) dihydrochloride were added. The monomer composition containing the monomer composition was weighed out into ion-exchanged water so that the solid content was 5% by weight.
  • the mixture was stirred at 200 rpm and polymerized at 70° C. for 24 hours under a nitrogen atmosphere. After the reaction was completed, it was freeze-dried to obtain insulating particles (average particle diameter 220 nm, CV value 10%) having ammonium groups on the surface.
  • the obtained insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10% by weight aqueous dispersion of insulating particles.
  • Nickel plating solution (pH 8.0) containing 0.14 mol/L of nickel sulfate, 1.45 mol/L of hydrazine, 0.90 mol/L of sodium stannate trihydrate, and 0.60 mol/L of sodium gluconate. prepared.
  • electroless nickel-tin alloy plating was performed at 58 ° C. using this nickel plating solution instead of nickel plating solutions (1), (2), and (3). Conductive particles were obtained.
  • Nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol/L, hydrazine 1.05 mol/L, sodium stannate trihydrate 0.30 mol/L, and sodium gluconate 0.30 mol/L prepared.
  • electroless nickel-tin alloy plating was performed at 65 ° C. using this nickel plating solution instead of nickel plating solutions (1), (2), and (3). Conductive particles were obtained.
  • the average content of nickel and tin, the maximum value of the content of tin in the above region R1, and the maximum value of the content of tin in the above region R2 were determined.
  • the content of tin in region R1 was determined out of the total 100% by weight of tin contained in the entire Ni--Sn conductive layer.
  • the region where the maximum value of the tin content exists is investigated, and the proportion of the region containing tin in the 100% thickness of the Ni-Sn conductive layer is determined. I asked for
  • a transparent glass substrate having an ITO electrode pattern with L/S of 20 ⁇ m/20 ⁇ m on the top surface was prepared. Further, a semiconductor chip having a gold electrode pattern with L/S of 20 ⁇ m/20 ⁇ m on the lower surface was prepared.
  • the anisotropic conductive paste was applied to a thickness of 30 ⁇ m on the transparent glass substrate to form an anisotropic conductive paste layer.
  • the semiconductor chips were stacked on the anisotropic conductive paste layer so that the electrodes faced each other.
  • a pressure heating head is placed on the top surface of the semiconductor chip, and a pressure of 1 MPa is applied to the anisotropic conductive paste layer. It was cured at 185°C to obtain a connected structure.
  • connection resistance between the upper and lower electrodes of the obtained connected structure was measured by a four-terminal method.
  • the initial connection resistance (A) was determined based on the following criteria.
  • connection resistance is 2.0 ⁇ or less
  • Connection resistance is over 2.0 ⁇ and 3.0 ⁇ or less
  • Connection resistance is over 3.0 ⁇ and 5.0 ⁇ or less
  • Connection resistance is 5.0 ⁇ exceeds 10 ⁇ or less
  • connection resistance (B) after being exposed to the presence of acid The obtained conductive particles were immersed in an 8% sulfuric acid aqueous solution at room temperature (23° C.) for 45 minutes. Thereafter, the particles were taken out by filtration, washed with water, replaced with ethanol, and allowed to stand for 10 minutes to dry the particles, thereby obtaining conductive particles exposed to acid.
  • a connected structure was produced using the obtained conductive particles in the same manner as in (2) above, and the connection resistance was measured in the same manner as the initial connection resistance (A).
  • the connection resistance (B) after being exposed to the presence of acid was determined based on the following criteria.
  • Connection resistance B is 1.0 times or more and less than 1.5 times the connection resistance A, and 10 ⁇ or less ⁇ : Connection resistance B is 1.5 times or more and less than 2.0 times the connection resistance A , and 10 ⁇ or less ⁇ : Connection resistance B is 2.0 times or more and less than 5.0 times the connection resistance A, and 10 ⁇ or less ⁇ : Connection resistance B is 5.0 times or more and less than 10 times the connection resistance A , and 10 ⁇ or less ⁇ : Connection resistance B is 10 times or more than connection resistance A, or exceeds 10 ⁇

Abstract

Provided are electroconductive particles which can reduce a connection resistance when electrodes are electrically connected to each other, and can prevent the transfer of charges in an Ni-Sn electroconductive layer even when exposed to a high voltage for a long period under a high-temperature and high-humidity environment.　Each of the electroconductive particles according to the present invention comprises a base particle and an Ni-Sn electroconductive layer containing nickel and tin, in which the Ni-Sn electroconductive layer is arranged on the surface of the base particle, the average content of tin in the whole region of the Ni-Sn electroconductive layer is less than 5% by weight, and the largest value of the content of tin in a region corresponding to a thickness-direction outer half of the Ni-Sn electroconductive layer is 5% by weight or more when the content of tin is measured in the direction of the thickness of the Ni-Sn electroconductive layer by TEM-EDX.

Description

導電性粒子、導電材料及び接続構造体Conductive particles, conductive materials and connected structures
　本発明は、基材粒子と、該基材粒子の表面上に配置された導電層とを有する導電性粒子に関する。また、本発明は、上記導電性粒子を用いた導電材料及び接続構造体に関する。 The present invention relates to conductive particles having a base particle and a conductive layer disposed on the surface of the base particle. The present invention also relates to a conductive material and a connected structure using the conductive particles described above.
　異方性導電ペースト及び異方性導電フィルム等の異方性導電材料が広く知られている。該異方性導電材料では、バインダー樹脂中に導電性粒子が分散されている。また、導電性粒子として、基材粒子と、該基材粒子の表面上に配置された導電部とを有する導電性粒子が用いられることがある。 Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. In the anisotropic conductive material, conductive particles are dispersed in a binder resin. Further, as the conductive particles, conductive particles having a base particle and a conductive portion disposed on the surface of the base particle may be used.
　上記異方性導電材料は、各種の接続構造体を得るために用いられている。上記異方性導電材料を用いる接続としては、フレキシブルプリント基板とガラス基板との接続（ＦＯＧ（Ｆｉｌｍ　ｏｎ　Ｇｌａｓｓ））、半導体チップとフレキシブルプリント基板との接続（ＣＯＦ（Ｃｈｉｐ　ｏｎ　Ｆｉｌｍ））、半導体チップとガラス基板との接続（ＣＯＧ（Ｃｈｉｐ　ｏｎ　Ｇｌａｓｓ））、並びにフレキシブルプリント基板とガラスエポキシ基板との接続（ＦＯＢ（Ｆｉｌｍ　ｏｎ　Ｂｏａｒｄ））等が挙げられる。 The above-mentioned anisotropic conductive material is used to obtain various connected structures. Connections using the above-mentioned anisotropic conductive material include connections between flexible printed circuit boards and glass substrates (FOG (Film on Glass)), connections between semiconductor chips and flexible printed circuit boards (COF (Chip on Film)), and semiconductor chips. Examples include connection between a flexible printed circuit board and a glass substrate (COG (Chip on Glass)), and connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)).
　導電性粒子が酸の存在下に晒されると、ニッケル等を含む導電層の腐食が生じることがある。また、そのような導電性粒子を用いて電極間を接続して接続構造体を得た場合には、接続構造体が酸の存在下に晒されると、電極間の接続抵抗が上昇することがある。このような理由から、酸の存在下に晒されても、導電層の腐食が生じ難い導電性粒子の開発が検討されている。 When conductive particles are exposed to the presence of acid, corrosion of the conductive layer containing nickel etc. may occur. In addition, when a connected structure is obtained by connecting electrodes using such conductive particles, the connection resistance between the electrodes may increase when the connected structure is exposed to the presence of acid. be. For these reasons, the development of conductive particles whose conductive layer is less likely to be corroded even when exposed to the presence of acid is being considered.
　上記導電性粒子の一例として、下記の特許文献１には、基材粒子と、上記基材粒子の表面上に配置されており、かつニッケルを含む導電層とを備える導電性粒子が開示されている。上記導電性粒子では、上記ニッケルを含む導電層の融点が３００℃以上である。上記導電性粒子では、上記ニッケルを含む導電層が、ニッケルと錫とを含む合金層であり、上記ニッケルを含む導電層の全体１００重量％中、錫の平均含有量が５重量％以上、５０重量％以下である。 As an example of the above conductive particles, Patent Document 1 below discloses conductive particles comprising base particles and a conductive layer disposed on the surface of the base particles and containing nickel. There is. In the conductive particles, the conductive layer containing nickel has a melting point of 300° C. or higher. In the conductive particles, the conductive layer containing nickel is an alloy layer containing nickel and tin, and the average content of tin is 5% by weight or more, based on 100% by weight of the entire conductive layer containing nickel. % by weight or less.
　下記の特許文献２には、基材粒子と、上記基材粒子の表面上に配置されており、かつニッケルを含む導電層とを備え、上記ニッケルを含む導電層が、ニッケルとスズ及びインジウムの内の少なくとも１種とを含む合金層である導電性粒子が開示されている。上記導電性粒子では、上記ニッケルを含む導電層の外表面から内側に向かって厚み１／２までの領域の１００重量％中、スズとインジウムとの合計の平均含有量が５重量％未満である。 Patent Document 2 below includes a base material particle and a conductive layer disposed on the surface of the base material particle and containing nickel, and the conductive layer containing nickel is composed of nickel, tin, and indium. Conductive particles are disclosed which are alloy layers containing at least one of the following. In the conductive particles, the total average content of tin and indium is less than 5% by weight in 100% by weight of the region from the outer surface of the nickel-containing conductive layer to 1/2 the thickness inward. .
特開２０１５－１３０３２８号公報Japanese Patent Application Publication No. 2015-130328 ＷＯ２０１７／１３８５２１Ａ１WO2017/138521A1
　近年、スマートウォッチやスマートグラス等のウェアラブルディスプレイや、各種センサー等に用いられる導電材料が注目されている。ウェアラブルディスプレイは、様々な環境で長時間連続して使用されることが前提であるので、ウェアラブルディスプレイに用いられる導電性粒子及び接続構造体には、高温、高湿かつ高電圧に長時間曝されても耐え得る性能が求められる。 In recent years, conductive materials used in wearable displays such as smart watches and smart glasses and various sensors have been attracting attention. Wearable displays are expected to be used continuously for long periods of time in various environments, so the conductive particles and connection structures used in wearable displays must be exposed to high temperature, high humidity, and high voltage for long periods of time. Performance that can withstand even the most extreme conditions is required.
　特許文献１に記載のような従来の導電性粒子を用いて、電極間を電気的に接続して接続構造体を得た場合には、錫の平均含有量が多いため、接続抵抗が高くなることがある。また、高温下に晒された導電性粒子を用いたり、導電性粒子を用いた接続構造体が高温下に晒されたりすると、接続抵抗が高くなりやすいという問題がある。 When a connected structure is obtained by electrically connecting electrodes using conventional conductive particles as described in Patent Document 1, the average content of tin is high, resulting in high connection resistance. Sometimes. Furthermore, there is a problem in that connection resistance tends to increase when conductive particles that have been exposed to high temperatures are used, or when a connected structure using conductive particles is exposed to high temperatures.
　一方、特許文献２に記載のような錫をごく微量で含む導電性粒子を用いて、接続構造体を得た場合、初期の接続抵抗及び低濃度の酸存在下での接続抵抗を比較的低くすることができるものの、より高濃度の酸の存在下では、接続抵抗を十分に低くすることは困難なことがある。さらに、特許文献２に記載のような導電性粒子は、高温かつ高湿な環境下で高電圧に長時間曝されると、金属腐食が発生し、導電層の電荷が移動することがある。結果として、ショートが発生したり、導通信頼性が低下したりすることがある。 On the other hand, when a connected structure is obtained using conductive particles containing a very small amount of tin as described in Patent Document 2, the initial connection resistance and the connection resistance in the presence of a low concentration of acid are relatively low. However, in the presence of higher concentrations of acid, it may be difficult to achieve a sufficiently low connection resistance. Furthermore, when conductive particles such as those described in Patent Document 2 are exposed to high voltage in a high temperature and high humidity environment for a long period of time, metal corrosion may occur and charges in the conductive layer may move. As a result, a short circuit may occur or conduction reliability may deteriorate.
　本発明の目的は、電極間を電気的に接続した場合に、接続抵抗を低くすることができ、高温かつ高湿な環境下で高電圧に長時間曝されても、Ｎｉ－Ｓｎ導電層における電荷の移動を防ぐことができる導電性粒子を提供することである。また、本発明の目的は、上記導電性粒子を用いた導電材料及び接続構造体を提供することである。 An object of the present invention is to reduce the connection resistance when electrically connecting electrodes, and to maintain the Ni-Sn conductive layer even when exposed to high voltage in a high temperature and high humidity environment for a long time. An object of the present invention is to provide conductive particles that can prevent charge transfer. Another object of the present invention is to provide a conductive material and a connected structure using the above-mentioned conductive particles.
　本発明の広い局面によれば、基材粒子と、ニッケルと錫とを含むＮｉ－Ｓｎ導電層とを備え、前記基材粒子の表面上に、前記Ｎｉ－Ｓｎ導電層が配置されており、前記Ｎｉ－Ｓｎ導電層の全体の領域における錫の平均含有量が５重量％未満であり、ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、５重量％以上である、導電性粒子が提供される。 According to a broad aspect of the present invention, the present invention comprises base particles and a Ni--Sn conductive layer containing nickel and tin, and the Ni--Sn conductive layer is disposed on the surface of the base particles, The average tin content in the entire area of the Ni-Sn conductive layer is less than 5% by weight, and when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the Ni -Sn Conductive particles are provided in which the maximum tin content is 5% by weight or more in the outer half-thickness region of the conductive layer.
　本発明に係る導電性粒子のある特定の局面では、ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、前記Ｎｉ－Ｓｎ導電層の全体に含まれる錫の合計１００重量％中の８０重量％以上の錫が含まれる。 In a particular aspect of the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the outer thickness of the Ni-Sn conductive layer is 1/ In the area No. 2, 80% by weight or more of tin is contained out of the total 100% by weight of tin contained in the entire Ni--Sn conductive layer.
　本発明に係る導電性粒子のある特定の局面では、ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の厚み１５％以上の領域において、錫が含まれる。 In a particular aspect of the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, it is found that the thickness of the Ni-Sn conductive layer is 15% or more. In the region, tin is included.
　本発明に係る導電性粒子のある特定の局面では、ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の厚み１０％以上かつ５０％未満の領域において、５重量％以上の含有量で錫が含まれる。 In a particular aspect of the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the thickness of the Ni-Sn conductive layer is 10% or more and In the region of less than 50%, tin is included in a content of 5% by weight or more.
　本発明に係る導電性粒子のある特定の局面では、ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の厚み１０％以上かつ５０％未満の領域において、５重量％以上の含有量で錫が含まれ、かつ、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、５重量％以上４０重量％以下である。 In a particular aspect of the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the thickness of the Ni-Sn conductive layer is 10% or more and In the region of less than 50%, tin is contained in a content of 5% by weight or more, and in the region of 1/2 the outer thickness of the Ni-Sn conductive layer, the maximum value of the tin content is 5% by weight. % or more and 40% by weight or less.
　本発明に係る導電性粒子のある特定の局面では、ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の厚み３０％以下の領域において、５重量％以上の含有量で錫が含まれる。 In a particular aspect of the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the thickness of the Ni-Sn conductive layer is 30% or less. In the region, tin is contained in a content of 5% by weight or more.
　本発明に係る導電性粒子のある特定の局面では、ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、１０重量％以上である。 In a particular aspect of the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the outer thickness of the Ni-Sn conductive layer is 1/ In region 2, the maximum tin content is 10% by weight or more.
　本発明に係る導電性粒子のある特定の局面では、ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の厚み３０％以下の領域において、５重量％以上の含有量で錫が含まれ、かつ、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、１０重量％以上である。 In a particular aspect of the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the thickness of the Ni-Sn conductive layer is 30% or less. The area contains tin in a content of 5% by weight or more, and the maximum value of the tin content is 10% by weight or more in the area of 1/2 the thickness outside the Ni-Sn conductive layer. .
　本発明に係る導電性粒子のある特定の局面では、前記導電性粒子の粒子径が、０．１μｍ以上１０００μｍ以下である。 In a particular aspect of the conductive particles according to the present invention, the conductive particles have a particle diameter of 0.1 μm or more and 1000 μm or less.
　本発明に係る導電性粒子のある特定の局面では、前記導電性粒子は、前記Ｎｉ－Ｓｎ導電層の外表面に複数の突起を有する。 In a particular aspect of the conductive particle according to the present invention, the conductive particle has a plurality of protrusions on the outer surface of the Ni—Sn conductive layer.
　本発明の広い局面によれば、上述した導電性粒子と、バインダー樹脂とを含む、導電材料が提供される。 According to a broad aspect of the present invention, a conductive material is provided that includes the above-described conductive particles and a binder resin.
　本発明の広い局面によれば、第１の電極を表面に有する第１の接続対象部材と、第２の電極を表面に有する第２の接続対象部材と、前記第１の接続対象部材と前記第２の接続対象部材とを接続している接続部とを備え、前記接続部が、上述した導電性粒子により形成されているか、又は前記導電性粒子とバインダー樹脂とを含む導電材料により形成されており、前記第１の電極と前記第２の電極とが前記導電性粒子により電気的に接続されている、接続構造体が提供される。 According to a broad aspect of the present invention, a first connection target member having a first electrode on its surface, a second connection target member having a second electrode on its surface, the first connection target member and the a connecting portion connecting a second connection target member, the connecting portion being formed of the above-mentioned conductive particles, or of a conductive material containing the conductive particles and a binder resin. A connected structure is provided, wherein the first electrode and the second electrode are electrically connected by the conductive particles.
　本発明に係る導電性粒子は、基材粒子と、ニッケルと錫とを含むＮｉ－Ｓｎ導電層とを備える。本発明に係る導電性粒子では、上記基材粒子の表面上に、上記Ｎｉ－Ｓｎ導電層が配置されており、上記Ｎｉ－Ｓｎ導電層の全体の領域における錫の平均含有量が５重量％未満である。本発明に係る導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、５重量％以上である。本発明に係る導電性粒子では、上記の構成が備えられているので、本発明に係る導電性粒子を用いて電極間を電気的に接続した場合に、接続抵抗を低くすることができ、高温かつ高湿な環境下で高電圧に長時間曝されても、Ｎｉ－Ｓｎ導電層における電荷の移動を防ぐことができる。 The conductive particles according to the present invention include base particles and a Ni—Sn conductive layer containing nickel and tin. In the conductive particles according to the present invention, the Ni-Sn conductive layer is arranged on the surface of the base particle, and the average tin content in the entire area of the Ni-Sn conductive layer is 5% by weight. less than In the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, in the outer half-thickness region of the Ni-Sn conductive layer, The maximum value of tin content is 5% by weight or more. Since the conductive particles according to the present invention have the above-mentioned configuration, when electrically connecting between electrodes using the conductive particles according to the present invention, connection resistance can be lowered, and high temperature Furthermore, even when exposed to high voltage for a long time in a high humidity environment, charge movement in the Ni--Sn conductive layer can be prevented.
図１は、本発明の第１の実施形態に係る導電性粒子を示す断面図である。FIG. 1 is a cross-sectional view showing conductive particles according to a first embodiment of the present invention. 図２は、本発明の第２の実施形態に係る導電性粒子を示す断面図である。FIG. 2 is a cross-sectional view showing conductive particles according to a second embodiment of the present invention. 図３は、本発明の第３の実施形態に係る導電性粒子を示す断面図である。FIG. 3 is a cross-sectional view showing conductive particles according to a third embodiment of the present invention. 図４は、本発明の第１の実施形態に係る導電性粒子におけるＮｉ－Ｓｎ導電層の各領域を説明するための模式図である。FIG. 4 is a schematic diagram for explaining each region of the Ni--Sn conductive layer in the conductive particles according to the first embodiment of the present invention. 図５は、本発明の第１の実施形態に係る導電性粒子を用いた接続構造体を模式的に示す断面図である。FIG. 5 is a cross-sectional view schematically showing a connected structure using conductive particles according to the first embodiment of the present invention.
　以下、本発明の詳細を説明する。 The details of the present invention will be explained below.
　（導電性粒子）
　従来、導電層がニッケルを含む場合に、ニッケルは腐食しやすいので、ニッケルが析出すると、電極間の接続抵抗が高くなりやすい。また、導電層にニッケルを含む導電性粒子が、高温かつ高湿な環境下で高電圧に曝されると、金属腐食が発生し、導電層の電荷が移動することがある。結果として、ショートが発生したり、導通信頼性が低下したりすることがある。 (conductive particles)
Conventionally, when a conductive layer contains nickel, nickel is easily corroded, so when nickel is deposited, the connection resistance between the electrodes tends to increase. Further, when conductive particles containing nickel in the conductive layer are exposed to high voltage in a high temperature and high humidity environment, metal corrosion may occur and charges in the conductive layer may move. As a result, a short circuit may occur or conduction reliability may deteriorate.
　本発明者は、ニッケルを含んでいても、初期の接続抵抗だけでなく、酸の存在下に晒された後の接続抵抗をも低くすることができ、高温かつ高湿な環境下で導電性粒子が高電圧に長時間曝されても、導電層における電荷の移動を抑制することができる導電性粒子について検討した。鋭意検討の結果、本発明者は、導電層内の錫の含有量及び分布に着目した。本発明者は、導電層全体での錫の含有量を抑えつつ、導電層中の錫の分布を工夫することにより、上記問題が解決することを見出した。 The present inventor has discovered that even if it contains nickel, it is possible to lower not only the initial connection resistance but also the connection resistance after being exposed to the presence of acid, and that it is conductive in high temperature and high humidity environments. We investigated conductive particles that can suppress charge transfer in a conductive layer even when the particles are exposed to high voltage for a long time. As a result of extensive studies, the inventors focused on the content and distribution of tin within the conductive layer. The present inventors have found that the above problem can be solved by controlling the tin content in the entire conductive layer and modifying the distribution of tin in the conductive layer.
　本発明に係る導電性粒子は、基材粒子と、ニッケルと錫とを含むＮｉ－Ｓｎ導電層とを備え、上記基材粒子の表面上に、上記Ｎｉ－Ｓｎ導電層が配置されている。本発明に係る導電性粒子では、上記Ｎｉ－Ｓｎ導電層の全体の領域における錫の平均含有量が５重量％未満である。本発明に係る導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、５重量％以上である。 The conductive particles according to the present invention include base particles and a Ni--Sn conductive layer containing nickel and tin, and the Ni--Sn conductive layer is arranged on the surface of the base particles. In the conductive particles according to the present invention, the average content of tin in the entire area of the Ni--Sn conductive layer is less than 5% by weight. In the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, in the outer half-thickness region of the Ni-Sn conductive layer, The maximum value of tin content is 5% by weight or more.
　本発明に係る導電性粒子における上述した構成の採用により、本発明に係る導電性粒子を用いて、電極間を電気的に接続した場合に、初期の接続抵抗を低くすることができる。さらに、酸の存在下に晒された後の接続抵抗を低くすることができる。さらに、高温（例えば、８５℃）かつ高湿（たとえば、８５％ＲＨ）な環境下で導電性粒子が高電圧（例えば、１５Ｖ）に長時間（例えば、５００時間）曝されても、Ｎｉ－Ｓｎ導電層における電荷の移動を防ぐことができる。 By employing the above-described configuration in the conductive particles according to the present invention, it is possible to reduce the initial connection resistance when electrically connecting electrodes using the conductive particles according to the present invention. Furthermore, connection resistance after exposure to the presence of acid can be reduced. Furthermore, even if the conductive particles are exposed to high voltage (e.g. 15V) for a long time (e.g. 500 hours) in a high temperature (e.g. 85°C) and high humidity (e.g. 85% RH) environment, Ni- Transfer of charges in the Sn conductive layer can be prevented.
　本発明では、高温かつ高湿な環境下などに長期間保管された導電性粒子を用いて、接続構造体を作製したときに、接続抵抗の上昇を抑えることができる。 In the present invention, when a connected structure is produced using conductive particles stored in a high temperature and high humidity environment for a long period of time, an increase in connection resistance can be suppressed.
　上記導電性粒子の粒子径は、好ましくは０．１μｍ以上、より好ましくは１μｍ以上であり、好ましくは１０００μｍ以下、より好ましくは５００μｍ以下、さらに好ましくは１００μｍ以下、特に好ましくは３０μｍ以下である。上記導電性粒子の粒子径が、上記下限以上及び上記上限以下であると、上記導電性粒子を用いて電極間を接続した場合に、導電性粒子と電極との接触面積が十分に大きくなり、かつ導電部を形成する際に凝集した導電性粒子が形成され難くなる。また、導電性粒子を介して接続された電極間の間隔が大きくなりすぎず、かつ導電部が基材粒子の表面から剥離し難くなる。 The particle diameter of the conductive particles is preferably 0.1 μm or more, more preferably 1 μm or more, preferably 1000 μm or less, more preferably 500 μm or less, still more preferably 100 μm or less, and particularly preferably 30 μm or less. When the particle diameter of the conductive particles is not less than the lower limit and not more than the upper limit, when the conductive particles are used to connect the electrodes, the contact area between the conductive particles and the electrodes is sufficiently large; In addition, agglomerated conductive particles are less likely to be formed when forming a conductive part. Moreover, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive part becomes difficult to peel off from the surface of the base particle.
　上記導電性粒子の粒子径は、導電性粒子が真球状である場合には直径を意味し、導電性粒子が真球状以外の形状である場合には、その体積相当の真球と仮定した際の直径を意味する。 The particle diameter of the conductive particles mentioned above means the diameter when the conductive particles are true spherical, and when the conductive particles have a shape other than true spherical, it is assumed that the conductive particles are true spheres equivalent to the volume. means the diameter of
　上記導電性粒子の粒子径は、平均粒子径であることが好ましく、数平均粒子径であることが好ましい。上記導電性粒子の粒子径は、例えば、任意の導電性粒子５０個を電子顕微鏡又は光学顕微鏡にて観察し、各導電性粒子の粒子径の平均値を算出することや、粒度分布測定装置を用いて求められる。電子顕微鏡又は光学顕微鏡での観察では、１個当たりの導電性粒子の粒子径は、円相当径での粒子径として求められる。電子顕微鏡又は光学顕微鏡での観察において、任意の５０個の導電性粒子の円相当径での平均粒子径は、球相当径での平均粒子径とほぼ等しくなる。粒度分布測定装置では、１個当たりの導電性粒子の粒子径は、球相当径での粒子径として求められる。上記導電性粒子の平均粒子径は、粒度分布測定装置を用いて算出することが好ましい。 The particle diameter of the conductive particles is preferably an average particle diameter, and preferably a number average particle diameter. The particle diameter of the above-mentioned conductive particles can be determined, for example, by observing 50 arbitrary conductive particles with an electron microscope or optical microscope and calculating the average value of the particle diameter of each conductive particle, or by using a particle size distribution measuring device. It can be found using In observation using an electron microscope or an optical microscope, the particle diameter of each conductive particle is determined as the particle diameter in equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter of any 50 conductive particles in equivalent circle diameter is approximately equal to the average particle diameter in equivalent sphere diameter. In the particle size distribution measuring device, the particle diameter of each conductive particle is determined as the particle diameter in equivalent sphere diameter. The average particle diameter of the conductive particles is preferably calculated using a particle size distribution measuring device.
　上記導電性粒子の粒子径の変動係数（ＣＶ値）は、好ましくは１０％以下、より好ましくは５％以下である。上記導電性粒子の粒子径の変動係数が、上記上限以下であると、電極間の導通信頼性及び絶縁信頼性をより一層効果的に高めることができる。上記導電性粒子の粒子径の変動係数の下限は特に限定されない。上記導電性粒子の粒子径の変動係数は、０％であってもよく、０％以上であってもよく、５％以上であってもよい。 The coefficient of variation (CV value) of the particle diameter of the conductive particles is preferably 10% or less, more preferably 5% or less. When the coefficient of variation of the particle diameter of the conductive particles is equal to or less than the above upper limit, the conduction reliability and insulation reliability between the electrodes can be further effectively improved. The lower limit of the coefficient of variation of the particle diameter of the conductive particles is not particularly limited. The coefficient of variation of the particle diameter of the conductive particles may be 0%, 0% or more, or 5% or more.
　上記変動係数（ＣＶ値）は、以下のようにして測定できる。 The above coefficient of variation (CV value) can be measured as follows.
　ＣＶ値（％）＝（ρ／Ｄｎ）×１００
　ρ：導電性粒子の粒子径の標準偏差
　Ｄｎ：導電性粒子の粒子径の平均値 CV value (%) = (ρ/Dn) x 100
ρ: Standard deviation of particle diameter of conductive particles Dn: Average value of particle diameter of conductive particles
　上記導電性粒子の形状は特に限定されない。上記導電性粒子の形状は、球状であってもよく、球状以外の形状であってもよく、扁平状等の形状であってもよい。 The shape of the conductive particles is not particularly limited. The conductive particles may have a spherical shape, a shape other than a spherical shape, a flat shape, or the like.
　以下、図面を参照しつつ、本発明の具体的な実施形態及び実施例を説明することにより、本発明を明らかにする。なお、参照した図面では、大きさ及び厚みなどは、図示の便宜上、実際の大きさ及び厚みから適宜変更している。 Hereinafter, the present invention will be clarified by describing specific embodiments and examples of the present invention with reference to the drawings. In the referenced drawings, the size, thickness, etc. are appropriately changed from the actual size and thickness for convenience of illustration.
　図１は、本発明の第１の実施形態に係る導電性粒子を示す断面図である。 FIG. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention.
　図１に示す導電性粒子１は、基材粒子２と、Ｎｉ－Ｓｎ導電層３とを有する。Ｎｉ－Ｓｎ導電層３は、ニッケルと錫とを含む。Ｎｉ－Ｓｎ導電層３は、基材粒子２の表面上に配置されている。第１の実施形態では、Ｎｉ－Ｓｎ導電層３は、基材粒子２の表面に接している。導電性粒子１は、基材粒子２の表面がＮｉ－Ｓｎ導電層３により被覆された被覆粒子である。 The conductive particles 1 shown in FIG. 1 have base particles 2 and a Ni—Sn conductive layer 3. Ni—Sn conductive layer 3 contains nickel and tin. The Ni—Sn conductive layer 3 is arranged on the surface of the base particle 2. In the first embodiment, the Ni—Sn conductive layer 3 is in contact with the surface of the base particle 2. The conductive particles 1 are coated particles in which the surface of a base particle 2 is coated with a Ni—Sn conductive layer 3.
　導電性粒子１では、Ｎｉ－Ｓｎ導電層３は、単層の導電層である。上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層が上記基材粒子の表面の全体を覆っていてもよく、上記Ｎｉ－Ｓｎ導電層が上記基材粒子の表面の一部を覆っていてもよい。上記導電性粒子は、上記Ｎｉ－Ｓｎ導電層以外の導電層を有していてもよい。上記導電性粒子は、複数の導電層を有していてもよい。 In the conductive particles 1, the Ni—Sn conductive layer 3 is a single-layer conductive layer. In the conductive particles, the Ni-Sn conductive layer may cover the entire surface of the base particle, or the Ni-Sn conductive layer may cover a part of the surface of the base particle. . The conductive particles may have a conductive layer other than the Ni--Sn conductive layer. The conductive particles may have multiple conductive layers.
　導電性粒子１は、後述する導電性粒子１１，２１とは異なり、芯物質を有さない。導電性粒子１は表面に突起を有さない。導電性粒子１は球状である。Ｎｉ－Ｓｎ導電層３は外表面に突起を有さない。このように、本発明に係る導電性粒子はＮｉ－Ｓｎ導電層の表面に突起を有していなくてもよく、球状であってもよい。また、導電性粒子１は、後述する導電性粒子１１，２１とは異なり、絶縁性物質を有さない。但し、導電性粒子１は、Ｎｉ－Ｓｎ導電層３の外表面上に配置された絶縁性物質を有していてもよい。 The conductive particles 1 do not have a core substance, unlike the conductive particles 11 and 21 described below. The conductive particles 1 do not have protrusions on the surface. The conductive particles 1 are spherical. The Ni--Sn conductive layer 3 has no protrusions on its outer surface. In this way, the conductive particles according to the present invention do not need to have protrusions on the surface of the Ni--Sn conductive layer, and may be spherical. Further, the conductive particles 1 do not have an insulating substance, unlike conductive particles 11 and 21 described later. However, the conductive particles 1 may have an insulating substance disposed on the outer surface of the Ni--Sn conductive layer 3.
　導電性粒子１では、Ｎｉ－Ｓｎ導電層３の全体の領域における錫の平均含有量が５重量％未満である。導電性粒子１では、ＴＥＭ－ＥＤＸによりＮｉ－Ｓｎ導電層３の厚み方向における錫の含有量を測定したときに、Ｎｉ－Ｓｎ導電層３の外側の厚み１／２の領域において、錫の含有量の最大値が、５重量％以上である。 In the conductive particles 1, the average content of tin in the entire area of the Ni--Sn conductive layer 3 is less than 5% by weight. In the conductive particles 1, when the tin content in the thickness direction of the Ni-Sn conductive layer 3 is measured by TEM-EDX, it is found that the tin content is found in the outer half-thickness region of the Ni-Sn conductive layer 3. The maximum amount is 5% by weight or more.
　図２は、本発明の第２の実施形態に係る導電性粒子を示す断面図である。 FIG. 2 is a cross-sectional view showing conductive particles according to the second embodiment of the present invention.
　図２に示す導電性粒子１１は、基材粒子２と、Ｎｉ－Ｓｎ導電層１２と、複数の芯物質１３と、複数の絶縁性物質１４とを有する。Ｎｉ－Ｓｎ導電層１２は、基材粒子２の表面上に基材粒子２に接するように配置されている。 The conductive particles 11 shown in FIG. 2 include a base particle 2, a Ni—Sn conductive layer 12, a plurality of core substances 13, and a plurality of insulating substances 14. The Ni—Sn conductive layer 12 is arranged on the surface of the base particle 2 so as to be in contact with the base particle 2.
　導電性粒子１１では、Ｎｉ－Ｓｎ導電層１２は、単層の導電層である。上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層が上記基材粒子の表面の全体を覆っていてもよく、上記Ｎｉ－Ｓｎ導電層が上記基材粒子の表面の一部を覆っていてもよい。上記導電性粒子は、上記Ｎｉ－Ｓｎ導電層以外の導電層を有していてもよい。上記導電性粒子は、多層の導電層を有していてもよい。 In the conductive particles 11, the Ni—Sn conductive layer 12 is a single-layer conductive layer. In the conductive particles, the Ni-Sn conductive layer may cover the entire surface of the base particle, or the Ni-Sn conductive layer may cover a part of the surface of the base particle. . The conductive particles may have a conductive layer other than the Ni--Sn conductive layer. The conductive particles may have multiple conductive layers.
　導電性粒子１１は表面に、複数の突起１１ａを有する。Ｎｉ－Ｓｎ導電層１２は外表面に、複数の突起１２ａを有する。複数の芯物質１３が、基材粒子２の表面上に配置されている。複数の芯物質１３は、Ｎｉ－Ｓｎ導電層１２内に埋め込まれている。芯物質１３は、突起１１ａ，１２ａの内側に配置されている。Ｎｉ－Ｓｎ導電層１２は、複数の芯物質１３を被覆している。複数の芯物質１３によりＮｉ－Ｓｎ導電層１２の外表面が***されており、突起１１ａ，１２ａが形成されている。 The conductive particles 11 have a plurality of protrusions 11a on the surface. The Ni--Sn conductive layer 12 has a plurality of protrusions 12a on its outer surface. A plurality of core substances 13 are arranged on the surface of the base particle 2. A plurality of core materials 13 are embedded within the Ni--Sn conductive layer 12. The core material 13 is arranged inside the protrusions 11a, 12a. A Ni--Sn conductive layer 12 covers a plurality of core materials 13. The outer surface of the Ni--Sn conductive layer 12 is raised by a plurality of core materials 13, and protrusions 11a and 12a are formed.
　導電性粒子１１は、Ｎｉ－Ｓｎ導電層１２の外表面上に配置された絶縁性物質１４を有する。Ｎｉ－Ｓｎ導電層１２の外表面の少なくとも一部の領域が、絶縁性物質１４により被覆されている。絶縁性物質１４は絶縁性を有する材料により形成されており、絶縁性粒子である。このように、本発明に係る導電性粒子は、Ｎｉ－Ｓｎ導電層の外表面上に配置された絶縁性物質を有していてもよい。但し、本発明に係る導電性粒子は、絶縁性物質を必ずしも有していなくてもよい。 The conductive particles 11 have an insulating material 14 disposed on the outer surface of the Ni--Sn conductive layer 12. At least a portion of the outer surface of the Ni--Sn conductive layer 12 is covered with an insulating material 14. The insulating substance 14 is made of an insulating material and is an insulating particle. Thus, the conductive particles according to the present invention may have an insulating material disposed on the outer surface of the Ni--Sn conductive layer. However, the conductive particles according to the present invention do not necessarily have to contain an insulating substance.
　導電性粒子１１では、Ｎｉ－Ｓｎ導電層１２の全体の領域における錫の平均含有量が５重量％未満である。導電性粒子１１では、ＴＥＭ－ＥＤＸによりＮｉ－Ｓｎ導電層１２の厚み方向における錫の含有量を測定したときに、Ｎｉ－Ｓｎ導電層１２の外側の厚み１／２の領域において、錫の含有量の最大値が、５重量％以上である。 In the conductive particles 11, the average content of tin in the entire area of the Ni--Sn conductive layer 12 is less than 5% by weight. In the conductive particles 11, when the tin content in the thickness direction of the Ni-Sn conductive layer 12 is measured by TEM-EDX, it is found that the tin content in the outer half-thickness region of the Ni-Sn conductive layer 12 is The maximum amount is 5% by weight or more.
　図３は、本発明の第３の実施形態に係る導電性粒子を示す断面図である。 FIG. 3 is a cross-sectional view showing conductive particles according to the third embodiment of the present invention.
　図３に示す導電性粒子２１は、基材粒子２と、Ｎｉ－Ｓｎ導電層２２Ａ（第１の導電層）と、複数の芯物質１３と、複数の絶縁性物質１４とを有する。導電性粒子２１は、基材粒子２側とは反対側にＮｉ－Ｓｎ導電層２２Ａ（第１の導電層）と、基材粒子２側に第２の導電層２２Ｂとを有する。 The conductive particles 21 shown in FIG. 3 include a base particle 2, a Ni--Sn conductive layer 22A (first conductive layer), a plurality of core substances 13, and a plurality of insulating substances 14. The conductive particles 21 have a Ni--Sn conductive layer 22A (first conductive layer) on the side opposite to the base particle 2 side, and a second conductive layer 22B on the base particle 2 side.
　導電性粒子１１と導電性粒子２１とでは、第２の導電層２２Ｂのみが異なっている。すなわち、導電性粒子１１では、１層構造の導電層が形成されているのに対し、導電性粒子２１では、２層構造の導電層が形成されている。導電性粒子１１では、Ｎｉ－Ｓｎ導電層１２が形成されているのに対し、導電性粒子２１では、Ｎｉ－Ｓｎ導電層２２Ａ（第１の導電層）及び第２の導電層２２Ｂが形成されている。導電性粒子２１では、Ｎｉ－Ｓｎ導電層２２Ａ（第１の導電層）と第２の導電層２２Ｂとは別の導電層として形成されている。 The only difference between the conductive particles 11 and the conductive particles 21 is the second conductive layer 22B. That is, in the conductive particles 11, a conductive layer having a single layer structure is formed, whereas in the conductive particles 21, a conductive layer having a two layer structure is formed. In the conductive particles 11, a Ni--Sn conductive layer 12 is formed, whereas in the conductive particles 21, a Ni--Sn conductive layer 22A (first conductive layer) and a second conductive layer 22B are formed. ing. In the conductive particles 21, a Ni--Sn conductive layer 22A (first conductive layer) and a second conductive layer 22B are formed as separate conductive layers.
　第２の導電層２２Ｂは、基材粒子２の表面上に配置されている。基材粒子２とＮｉ－Ｓｎ導電層２２Ａ（第１の導電層）との間に、第２の導電層２２Ｂが配置されている。第２の導電層２２Ｂは、基材粒子２に接している。Ｎｉ－Ｓｎ導電層２２Ａ（第１の導電層）は、第２の導電層２２Ｂに接している。従って、基材粒子２の表面上に第２の導電層２２Ｂが配置されており、第２の導電層２２Ｂの表面上にＮｉ－Ｓｎ導電層２２Ａ（第１の導電層）が配置されている。導電性粒子２１は表面に、複数の突起２１ａを有する。Ｎｉ－Ｓｎ導電層２２Ａ（第１の導電層）は外表面に、複数の突起２２Ａａを有する。第２の導電層２２Ｂは外表面に、複数の突起２２Ｂａを有する。 The second conductive layer 22B is arranged on the surface of the base particle 2. A second conductive layer 22B is arranged between the base material particles 2 and the Ni--Sn conductive layer 22A (first conductive layer). The second conductive layer 22B is in contact with the base particle 2. The Ni--Sn conductive layer 22A (first conductive layer) is in contact with the second conductive layer 22B. Therefore, the second conductive layer 22B is disposed on the surface of the base particle 2, and the Ni--Sn conductive layer 22A (first conductive layer) is disposed on the surface of the second conductive layer 22B. . The conductive particles 21 have a plurality of protrusions 21a on their surfaces. The Ni--Sn conductive layer 22A (first conductive layer) has a plurality of protrusions 22Aa on its outer surface. The second conductive layer 22B has a plurality of protrusions 22Ba on its outer surface.
　導電性粒子２１では、Ｎｉ－Ｓｎ導電層２２Ａの全体の領域における錫の平均含有量が５重量％未満である。導電性粒子２１では、ＴＥＭ－ＥＤＸによりＮｉ－Ｓｎ導電層２２Ａの厚み方向における錫の含有量を測定したときに、Ｎｉ－Ｓｎ導電層２２Ａの外側の厚み１／２の領域において、錫の含有量の最大値が、５重量％以上である。 In the conductive particles 21, the average tin content in the entire area of the Ni--Sn conductive layer 22A is less than 5% by weight. In the conductive particles 21, when the tin content in the thickness direction of the Ni-Sn conductive layer 22A is measured by TEM-EDX, it is found that the tin content is found in the outer half-thickness region of the Ni-Sn conductive layer 22A. The maximum amount is 5% by weight or more.
　以下、基材粒子及びＮｉ－Ｓｎ導電層の詳細を説明する。 Hereinafter, details of the base material particles and the Ni--Sn conductive layer will be explained.
　（基材粒子）
　上記基材粒子の材料は特に限定されない。上記基材粒子の材料は、有機材料であってもよく、無機材料であってもよい。上記有機材料のみにより形成された基材粒子としては、樹脂粒子等が挙げられる。上記無機材料のみにより形成された基材粒子としては、金属を除く無機粒子等が挙げられる。上記有機材料と上記無機材料との双方により形成された基材粒子としては、有機無機ハイブリッド粒子等が挙げられる。基材粒子の圧縮特性をより一層良好にする観点からは、上記基材粒子は、樹脂粒子又は有機無機ハイブリッド粒子であることが好ましく、樹脂粒子であることがより好ましい。 (Base material particles)
The material of the base particles is not particularly limited. The material of the base particles may be an organic material or an inorganic material. Examples of the base material particles formed only from the above-mentioned organic material include resin particles. Examples of the base material particles formed only from the above-mentioned inorganic material include inorganic particles excluding metals. Examples of the base particles formed of both the organic material and the inorganic material include organic-inorganic hybrid particles. From the viewpoint of further improving the compression characteristics of the base particles, the base particles are preferably resin particles or organic-inorganic hybrid particles, and more preferably resin particles.
　上記有機材料としては、ポリエチレン、ポリプロピレン、ポリスチレン、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリイソブチレン、ポリブタジエン等のポリオレフィン樹脂；ポリメチルメタクリレート及びポリメチルアクリレート等のアクリル樹脂；ポリカーボネート、ポリアミド、フェノールホルムアルデヒド樹脂、メラミンホルムアルデヒド樹脂、ベンゾグアナミンホルムアルデヒド樹脂、尿素ホルムアルデヒド樹脂、フェノール樹脂、メラミン樹脂、ベンゾグアナミン樹脂、尿素樹脂、エポキシ樹脂、不飽和ポリエステル樹脂、飽和ポリエステル樹脂、ポリエチレンテレフタレート、ポリスルホン、ポリフェニレンオキサイド、ポリアセタール、ポリイミド、ポリアミドイミド、ポリエーテルエーテルケトン、ポリエーテルスルホン、及びジビニルベンゼン重合体等が挙げられる。上記ジビニルベンゼン重合体は、ジビニルベンゼン共重合体であってもよい。上記ジビニルベンゼン共重合体等としては、ジビニルベンゼン－スチレン共重合体及びジビニルベンゼン－（メタ）アクリル酸エステル共重合体等が挙げられる。上記基材粒子の圧縮特性を好適な範囲に容易に制御できるので、上記基材粒子の材料は、エチレン性不飽和基を有する重合性単量体を１種又は２種以上重合させた重合体であることが好ましい。 The organic materials mentioned above include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; polycarbonate, polyamide, phenol formaldehyde resin, and melamine. Formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenolic resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, Examples include polyetheretherketone, polyethersulfone, and divinylbenzene polymer. The divinylbenzene polymer may be a divinylbenzene copolymer. Examples of the divinylbenzene copolymer and the like include divinylbenzene-styrene copolymer and divinylbenzene-(meth)acrylic acid ester copolymer. Since the compression properties of the base particles can be easily controlled within a suitable range, the material of the base particles is a polymer obtained by polymerizing one or more polymerizable monomers having ethylenically unsaturated groups. It is preferable that
　上記基材粒子を、エチレン性不飽和基を有する重合性単量体を重合させて得る場合、上記エチレン性不飽和基を有する重合性単量体としては、非架橋性の単量体と架橋性の単量体とが挙げられる。 When the base particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group includes a non-crosslinkable monomer and a crosslinkable monomer. Examples include monomers with different characteristics.
　上記非架橋性の単量体としては、ビニル化合物として、スチレン、α－メチルスチレン、クロルスチレン等のスチレン単量体；メチルビニルエーテル、エチルビニルエーテル、プロピルビニルエーテル等のビニルエーテル化合物；酢酸ビニル、酪酸ビニル、ラウリン酸ビニル、ステアリン酸ビニル等の酸ビニルエステル化合物；塩化ビニル、フッ化ビニル等のハロゲン含有単量体；（メタ）アクリル化合物として、メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、ブチル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート、ラウリル（メタ）アクリレート、セチル（メタ）アクリレート、ステアリル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレート等のアルキル（メタ）アクリレート化合物；２－ヒドロキシエチル（メタ）アクリレート、グリセロール（メタ）アクリレート、ポリオキシエチレン（メタ）アクリレート、グリシジル（メタ）アクリレート等の酸素原子含有（メタ）アクリレート化合物；（メタ）アクリロニトリル等のニトリル含有単量体；トリフルオロメチル（メタ）アクリレート、ペンタフルオロエチル（メタ）アクリレート等のハロゲン含有（メタ）アクリレート化合物；α－オレフィン化合物として、ジイソブチレン、イソブチレン、リニアレン、エチレン、プロピレン等のオレフィン化合物；共役ジエン化合物として、イソプレン、ブタジエン等が挙げられる。 Examples of the non-crosslinking monomer include vinyl compounds such as styrene monomers such as styrene, α-methylstyrene, and chlorostyrene; vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; vinyl acetate, vinyl butyrate, Acid vinyl ester compounds such as vinyl laurate and vinyl stearate; halogen-containing monomers such as vinyl chloride and vinyl fluoride; (meth)acrylic compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate; ) acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc. meth)acrylate compounds; oxygen atom-containing (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, glycidyl (meth)acrylate; (meth)acrylonitrile, etc. Nitrile-containing monomers; halogen-containing (meth)acrylate compounds such as trifluoromethyl (meth)acrylate and pentafluoroethyl (meth)acrylate; α-olefin compounds such as olefins such as diisobutylene, isobutylene, linear alene, ethylene, and propylene Compound: Examples of conjugated diene compounds include isoprene and butadiene.
　上記架橋性の単量体としては、ビニル化合物として、ジビニルベンゼン、１，４－ジビニロキシブタン、ジビニルスルホン等のビニル単量体；（メタ）アクリル化合物として、テトラメチロールメタンテトラ（メタ）アクリレート、ポリテトラメチレングリコールジアクリレート、テトラメチロールメタントリ（メタ）アクリレート、テトラメチロールメタンジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、ジペンタエリスリトールペンタ（メタ）アクリレート、グリセロールトリ（メタ）アクリレート、グリセロールジ（メタ）アクリレート、ポリエチレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート、ポリテトラメチレングリコールジ（メタ）アクリレート、１，４－ブタンジオールジ（メタ）アクリレート等の多官能（メタ）アクリレート化合物；アリル化合物として、トリアリル（イソ）シアヌレート、トリアリルトリメリテート、ジアリルフタレート、ジアリルアクリルアミド、ジアリルエーテル；シラン化合物として、テトラメトキシシラン、テトラエトキシシラン、メチルトリメトキシシラン、メチルトリエトキシシラン、エチルトリメトキシシラン、エチルトリエトキシシラン、イソプロピルトリメトキシシラン、イソブチルトリメトキシシラン、シクロヘキシ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－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、ジメチルジメトキシシラン、ジメチルジエトキシシラン、ジイソプロピルジメトキシシラン、トリメトキシシリルスチレン、γ－（メタ）アクリロキシプロピルトリメトキシシラン、１，３－ジビニルテトラメチルジシロキサン、メチルフェニルジメトキシシラン、ジフェニルジメトキシシラン等のシランアルコキシド化合物；ビニルトリメトキシシラン、ビニルトリエトキシシラン、ジメトキシメチルビニルシシラン、ジメトキシエチルビニルシラン、ジエトキシメチルビニルシラン、ジエトキシエチルビニルシラン、エチルメチルジビニルシラン、メチルビニルジメトキシシラン、エチルビニルジメトキシシラン、メチルビニルジエトキシシラン、エチルビニルジエトキシシラン、ｐ－スチリルトリメトキシシラン、３－メタクリロキシプロピルメチルジメトキシシラン、３－メタクリロキシプロピルトリメトキシシラン、３－メタクリロキシプロピルメチルジエトキシシラン、３－メタクリロキシプロピルトリエトキシシラン、３－アクリロキシプロピルトリメトキシシラン等の重合性二重結合含有シランアルコキシド；デカメチルシクロペンタシロキサン等の環状シロキサン；片末端変性シリコーンオイル、両末端シリコーンオイル、側鎖型シリコーンオイル等の変性（反応性）シリコーンオイル；（メタ）アクリル酸、マレイン酸、無水マレイン酸等のカルボキシル基含有単量体等が挙げられる。 Examples of the crosslinking monomer include vinyl monomers such as divinylbenzene, 1,4-divinyloxybutane, and divinylsulfone as vinyl compounds; tetramethylolmethanetetra(meth)acrylate as (meth)acrylic compounds; , polytetramethylene glycol diacrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate ) acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, 1,4-butanediol di Polyfunctional (meth)acrylate compounds such as (meth)acrylate; As allyl compounds, triallyl(iso)cyanurate, triallyl trimellitate, diallyl phthalate, diallylacrylamide, diallyl ether; As silane compounds, tetramethoxysilane, tetraethoxysilane , methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isopropyltrimethoxysilane, isobutyltrimethoxysilane, cyclohexyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, trimethoxysilylstyrene, γ-(meth)acryloxypropyltrimethoxysilane, 1,3-divinyltetramethyldimethoxysilane Silane alkoxide compounds such as siloxane, methylphenyldimethoxysilane, diphenyldimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsilane, dimethoxyethylvinylsilane, diethoxymethylvinylsilane, diethoxyethylvinylsilane, ethylmethyldivinylsilane , methylvinyldimethoxysilane, ethylvinyldimethoxysilane, methylvinyldiethoxysilane, ethylvinyldiethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- Polymerizable double bond-containing silane alkoxides such as methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane; cyclic siloxanes such as decamethylcyclopentasiloxane; single-end modified silicones Examples include modified (reactive) silicone oils such as oil, double-terminated silicone oil, and side chain type silicone oil; carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride.
　上記基材粒子は、上記エチレン性不飽和基を有する重合性単量体を重合させることによって得ることができる。上記の重合方法としては特に限定されず、ラジカル重合、イオン重合、重縮合（縮合重合、縮重合）、付加縮合、リビング重合、及びリビングラジカル重合等の公知の方法が挙げられる。また、他の重合方法としては、ラジカル重合開始剤の存在下での懸濁重合が挙げられる。 The above-mentioned base material particles can be obtained by polymerizing the above-mentioned polymerizable monomer having an ethylenically unsaturated group. The above polymerization method is not particularly limited, and includes known methods such as radical polymerization, ionic polymerization, polycondensation (condensation polymerization, condensation polymerization), addition condensation, living polymerization, and living radical polymerization. Other polymerization methods include suspension polymerization in the presence of a radical polymerization initiator.
　上記無機材料としては、シリカ、アルミナ、チタン酸バリウム、ジルコニア、カーボンブラック、ケイ酸ガラス、ホウケイ酸ガラス、鉛ガラス、ソーダ石灰ガラス及びアルミナシリケートガラス等が挙げられる。 Examples of the inorganic materials include silica, alumina, barium titanate, zirconia, carbon black, silicate glass, borosilicate glass, lead glass, soda-lime glass, and alumina-silicate glass.
　上記基材粒子は、有機無機ハイブリッド粒子であってもよい。上記基材粒子は、コアシェル粒子であってもよい。上記基材粒子が有機無機ハイブリッド粒子である場合に、上記基材粒子の材料である無機物としては、シリカ、アルミナ、チタン酸バリウム、ジルコニア及びカーボンブラック等が挙げられる。上記無機物は金属ではないことが好ましい。上記シリカにより形成された基材粒子としては特に限定されないが、加水分解性のアルコキシシリル基を２つ以上持つケイ素化合物を加水分解して架橋重合体粒子を形成した後に、必要に応じて焼成を行うことにより得られる基材粒子が挙げられる。上記有機無機ハイブリッド粒子としては、架橋したアルコキシシリルポリマーとアクリル樹脂とにより形成された有機無機ハイブリッド粒子等が挙げられる。 The base particles may be organic-inorganic hybrid particles. The base particles may be core-shell particles. When the base particles are organic-inorganic hybrid particles, examples of the inorganic material of the base particles include silica, alumina, barium titanate, zirconia, and carbon black. Preferably, the inorganic substance is not a metal. The base particles formed from the silica are not particularly limited, but after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, baking may be performed as necessary. Examples include base material particles obtained by carrying out this method. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed from a crosslinked alkoxysilyl polymer and an acrylic resin.
　上記有機無機ハイブリッド粒子は、コアと、該コアの表面上に配置されたシェルとを有するコアシェル型の有機無機ハイブリッド粒子であることが好ましい。上記コアが有機コアであることが好ましい。上記シェルが無機シェルであることが好ましい。上記基材粒子は、有機コアと上記有機コアの表面上に配置された無機シェルとを有する有機無機ハイブリッド粒子であることが好ましい。 The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell disposed on the surface of the core. Preferably, the core is an organic core. Preferably, the shell is an inorganic shell. The base particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell disposed on the surface of the organic core.
　上記有機コアの材料としては、上述した有機材料等が挙げられる。 Examples of the material for the organic core include the organic materials described above.
　上記無機シェルの材料としては、上述した基材粒子の材料として挙げた無機物が挙げられる。上記無機シェルの材料は、シリカであることが好ましい。上記無機シェルは、上記コアの表面上で、金属アルコキシドをゾルゲル法によりシェル状物とした後、該シェル状物を焼成させることにより形成されていることが好ましい。上記金属アルコキシドはシランアルコキシドであることが好ましい。上記無機シェルはシランアルコキシドにより形成されていることが好ましい。 Examples of the material for the inorganic shell include the inorganic substances listed as the material for the base particles described above. The material of the inorganic shell is preferably silica. The inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material by a sol-gel method on the surface of the core, and then firing the shell-like material. Preferably, the metal alkoxide is a silane alkoxide. The inorganic shell is preferably formed of silane alkoxide.
　上記基材粒子の粒子径は、好ましくは０．１μｍ以上、より好ましくは１μｍ以上である。上記基材粒子の粒子径は、好ましくは１０００μｍ以下、より好ましくは５００μｍ以下、さらに好ましくは１００μｍ以下、特に好ましくは３０μｍ以下、最も好ましくは１０μｍ以下である。上記基材粒子の粒子径が上記下限以上であると、導電性粒子と電極との接触面積が大きくなるため、電極間の導通信頼性を高めることができ、導電性粒子を介して接続された電極間の接続抵抗をより一層低くすることができる。さらに、基材粒子の表面に導電部を無電解めっきにより形成する際に、凝集した導電性粒子を形成され難くすることができる。上記基材粒子の粒子径が上記上限以下であると、導電性粒子が十分に圧縮されやすく、電極間の接続抵抗をより一層低くすることができ、さらに電極間の間隔をより小さくすることができる。 The particle diameter of the base particles is preferably 0.1 μm or more, more preferably 1 μm or more. The particle size of the base particles is preferably 1000 μm or less, more preferably 500 μm or less, even more preferably 100 μm or less, particularly preferably 30 μm or less, and most preferably 10 μm or less. When the particle size of the base material particles is equal to or larger than the lower limit, the contact area between the conductive particles and the electrodes becomes large, which increases the reliability of conduction between the electrodes, and the connection between the conductive particles through the conductive particles increases. The connection resistance between the electrodes can be further reduced. Furthermore, when forming a conductive part on the surface of the base material particle by electroless plating, it is possible to make it difficult to form agglomerated conductive particles. When the particle diameter of the base particles is below the above upper limit, the conductive particles are easily compressed, and the connection resistance between the electrodes can be further lowered, and the distance between the electrodes can be further reduced. can.
　上記基材粒子の粒子径は、基材粒子が真球状である場合には、直径を示し、基材粒子が真球状以外の形状である場合には、その体積相当の真球と仮定した際の直径を意味する。 The particle diameter of the base material particle mentioned above indicates the diameter when the base material particle is true spherical, and when the base material particle has a shape other than true spherical shape, it is assumed that the base material particle is a true sphere equivalent to the volume. means the diameter of
　上記基材粒子の粒子径は、数平均粒子径を示す。上記基材粒子の粒子径は、任意の基材粒子５０個を電子顕微鏡又は光学顕微鏡にて観察し、各基材粒子の粒子径の平均値を算出することや、粒度分布測定装置を用いて求められる。電子顕微鏡又は光学顕微鏡での観察では、１個当たりの基材粒子の粒子径は、円相当径での粒子径として求められる。電子顕微鏡又は光学顕微鏡での観察において、任意の５０個の基材粒子の円相当径での平均粒子径は、球相当径での平均粒子径とほぼ等しくなる。粒度分布測定装置では、１個当たりの基材粒子の粒子径は、球相当径での粒子径として求められる。上記基材粒子の平均粒子径は、粒度分布測定装置を用いて算出することが好ましい。 The particle diameter of the above-mentioned base material particles indicates the number average particle diameter. The particle diameter of the above-mentioned base material particles can be determined by observing 50 arbitrary base material particles with an electron microscope or optical microscope and calculating the average value of the particle diameter of each base material particle, or by using a particle size distribution measuring device. Desired. In observation using an electron microscope or an optical microscope, the particle diameter of each base particle is determined as the particle diameter in equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter of any 50 base particles in equivalent circle diameter is approximately equal to the average particle diameter in equivalent sphere diameter. In the particle size distribution measuring device, the particle diameter of each base material particle is determined as the particle diameter in equivalent sphere diameter. The average particle diameter of the base particles is preferably calculated using a particle size distribution measuring device.
　導電性粒子において、上記基材粒子の粒子径を測定する場合には、例えば、以下のようにして測定できる。導電性粒子の含有量が３０重量％となるように、Ｋｕｌｚｅｒ社製「テクノビット４０００」に添加し、分散させて、導電性粒子検査用埋め込み樹脂体を作製する。検査用埋め込み樹脂体中に分散した導電性粒子の基材粒子の中心付近を通るようにイオンミリング装置（日立ハイテクノロジーズ社製「ＩＭ４０００」）を用いて、導電性粒子の断面を切り出す。そして、電界放射型走査型電子顕微鏡（ＦＥ－ＳＥＭ）を用いて、画像倍率を２５０００倍に設定し、５０個の導電性粒子を無作為に選択し、各導電性粒子の基材粒子を観察する。各導電性粒子における基材粒子の粒子径を計測し、それらを算術平均して基材粒子の粒子径とする。 When measuring the particle diameter of the base particle in the conductive particles, for example, it can be measured as follows. A conductive particle content of 30% by weight is added to "Technovit 4000" manufactured by Kulzer and dispersed to prepare an embedded resin body for conductive particle inspection. Using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies), a cross section of the conductive particles is cut out so as to pass through the center of the base particle of the conductive particles dispersed in the embedded resin body for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification was set to 25,000 times, 50 conductive particles were randomly selected, and the base material particles of each conductive particle were observed. do. The particle diameter of the base material particle in each conductive particle is measured, and the arithmetic average of the measurements is taken as the particle diameter of the base material particle.
　（Ｎｉ－Ｓｎ導電層）
　上記導電性粒子は、ニッケルと錫とを含むＮｉ－Ｓｎ導電層を備える。上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層の全体の領域における錫の平均含有量が５重量％未満である。上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、錫の含有量の最大値が、５重量％以上である。上記領域Ｒ１は、上記Ｎｉ－Ｓｎ導電層の外側の厚み５０％の領域である。 (Ni-Sn conductive layer)
The conductive particles include a Ni--Sn conductive layer containing nickel and tin. In the conductive particles, the average tin content in the entire area of the Ni--Sn conductive layer is less than 5% by weight. In the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, in the outer half-thickness region (R1) of the Ni-Sn conductive layer, The maximum value of tin content is 5% by weight or more. The region R1 is a region having a thickness of 50% outside the Ni--Sn conductive layer.
　図４は、本発明の第１の実施形態に係る導電性粒子におけるＮｉ－Ｓｎ導電層の各領域を説明するための模式図である。図４は、導電性粒子１におけるＮｉ－Ｓｎ導電層３の各領域を説明するための模式図である。 FIG. 4 is a schematic diagram for explaining each region of the Ni—Sn conductive layer in the conductive particles according to the first embodiment of the present invention. FIG. 4 is a schematic diagram for explaining each region of the Ni—Sn conductive layer 3 in the conductive particle 1. As shown in FIG.
　上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）は、Ｎｉ－Ｓｎ導電層の外表面から内側に向かって、Ｎｉ－Ｓｎ導電層の厚みの１／２までの領域である。上記領域Ｒ１は、図４において、Ｎｉ－Ｓｎ導電層３の破線Ｌ１よりも外側の領域である。上記領域Ｒ１は、Ｎｉ－Ｓｎ導電層３の外表面部分である。上記領域Ｒ１は、Ｎｉ－Ｓｎ導電層３の基材粒子２側の領域とは異なる領域である。 The outer 1/2 thickness region (R1) of the Ni-Sn conductive layer is a region extending from the outer surface of the Ni-Sn conductive layer inward to 1/2 the thickness of the Ni-Sn conductive layer. . The region R1 is the region outside the broken line L1 of the Ni—Sn conductive layer 3 in FIG. The region R1 is the outer surface portion of the Ni—Sn conductive layer 3. The region R1 is a region different from the region of the Ni—Sn conductive layer 3 on the base particle 2 side.
　上記Ｎｉ－Ｓｎ導電層の内側の厚み１／２の領域（Ｒ２）は、Ｎｉ－Ｓｎ導電層の内表面から外側に向かって、Ｎｉ－Ｓｎ導電層の厚みの１／２までの領域である。上記領域Ｒ２は、図４において、Ｎｉ－Ｓｎ導電層３の破線Ｌ１よりも内側の領域である。上記領域Ｒ２は、Ｎｉ－Ｓｎ導電層３の基材粒子２側の領域である。上記領域Ｒ２は、Ｎｉ－Ｓｎ導電層３の外表面部分とは異なる領域である。 The inner 1/2 thickness region (R2) of the Ni-Sn conductive layer is a region extending from the inner surface of the Ni-Sn conductive layer toward the outside to 1/2 the thickness of the Ni-Sn conductive layer. . The region R2 is a region inside the broken line L1 of the Ni--Sn conductive layer 3 in FIG. The region R2 is a region of the Ni—Sn conductive layer 3 on the base particle 2 side. The region R2 is a region different from the outer surface portion of the Ni—Sn conductive layer 3.
　上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層の全体の領域における錫の平均含有量は、５重量％未満である。上記導電性粒子では、上記の構成が備えられているので、初期抵抗を低くすることができる。初期抵抗をより一層低くする観点からは、上記Ｎｉ－Ｓｎ導電層の全体の領域における錫の平均含有量は、好ましくは４．５重量％以下、より好ましくは４．０重量％以下、さらに好ましくは３．５重量％以下である。酸の存在下に晒された後の接続抵抗をより一層低くする観点からは、上記Ｎｉ－Ｓｎ導電層の全体の領域における錫の平均含有量は、０重量％を超え、好ましくは０．１重量％以上、より好ましくは０．５重量％以上である。 In the conductive particles, the average content of tin in the entire area of the Ni—Sn conductive layer is less than 5% by weight. Since the conductive particles have the above configuration, the initial resistance can be lowered. From the viewpoint of further lowering the initial resistance, the average tin content in the entire area of the Ni-Sn conductive layer is preferably 4.5% by weight or less, more preferably 4.0% by weight or less, and even more preferably is 3.5% by weight or less. From the viewpoint of further lowering the connection resistance after being exposed to the presence of an acid, the average content of tin in the entire area of the Ni--Sn conductive layer exceeds 0% by weight, preferably 0.1% by weight. It is at least 0.5% by weight, more preferably at least 0.5% by weight.
　上記Ｎｉ－Ｓｎ層は、ニッケルを主金属として含むことが好ましい。上記Ｎｉ－Ｓｎ導電層の全体の領域におけるニッケルの平均含有量は、好ましくは５０重量％以上、より好ましくは８０重量％以上であり、好ましくは９９．９重量％以下、より好ましくは９９．５重量％以下である。 The Ni—Sn layer preferably contains nickel as a main metal. The average content of nickel in the entire area of the Ni--Sn conductive layer is preferably 50% by weight or more, more preferably 80% by weight or more, and preferably 99.9% by weight or less, more preferably 99.5% by weight. % by weight or less.
　上記Ｎｉ－Ｓｎ導電層の全体の領域におけるニッケル及び錫の平均含有量は、ＩＣＰ－ＭＳ法等により測定することができる。 The average content of nickel and tin in the entire area of the Ni--Sn conductive layer can be measured by ICP-MS method or the like.
　上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、錫の含有量の最大値が、５重量％以上である。上記導電性粒子では、上記の構成が備えられているので、高温かつ高湿な環境下で高電圧に長時間曝されても、Ｎｉ－Ｓｎ導電層における電荷の移動を防ぐことができる。 In the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, in the outer half-thickness region (R1) of the Ni-Sn conductive layer, The maximum value of tin content is 5% by weight or more. Since the conductive particles have the above-described structure, it is possible to prevent charge movement in the Ni--Sn conductive layer even when exposed to high voltage for a long time in a high temperature and high humidity environment.
　上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記Ｎｉ－Ｓｎ導電層の錫の含有量の最大値が、上記領域Ｒ１に存在することが好ましい。上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層の全体の領域における錫の含有量の最大値が、上記領域Ｒ１に存在することが好ましい。上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層の全体の領域における錫の含有量の最大値が存在する領域が、上記領域Ｒ１であることが好ましい。上記導電性粒子では、錫の含有量が、上記領域Ｒ１において最大値となることが好ましい。上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記領域Ｒ１における錫の含有量の最大値が、上記領域Ｒ２における錫の含有量の最大値より大きいことが好ましい。上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記Ｎｉ－Ｓｎ導電層の錫の含有量の最大値が、上記領域Ｒ１における錫の含有量の最大値であることが好ましい。 In the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the maximum value of the tin content of the Ni-Sn conductive layer is in the region R1. Preferably present. In the conductive particles, it is preferable that the maximum tin content in the entire region of the Ni—Sn conductive layer exists in the region R1. In the conductive particles, it is preferable that the region where the tin content has the maximum value in the entire region of the Ni—Sn conductive layer is the region R1. In the conductive particles, the tin content preferably reaches a maximum value in the region R1. In the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the maximum tin content in the region R1 is the tin content in the region R2. Preferably, the amount is greater than the maximum value. In the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the maximum value of the tin content in the Ni-Sn conductive layer is in the region R1. The maximum tin content is preferred.
　上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層の厚み方向において、錫が偏在している。上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層の厚み方向において、錫の分布に偏りがある。 In the conductive particles, tin is unevenly distributed in the thickness direction of the Ni--Sn conductive layer. In the conductive particles, tin is unevenly distributed in the thickness direction of the Ni--Sn conductive layer.
　上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層において、上記領域Ｒ２の錫の含有量よりも上記領域Ｒ１の錫の含有量の方が多いように、錫の含有量が異なることが好ましく、錫の含有量が勾配を有することが好ましい。上記Ｎｉ－Ｓｎ導電層において、錫が、上記領域Ｒ２よりも上記領域Ｒ１の方で多く存在するように偏在していることが好ましい。上記Ｎｉ－Ｓｎ導電層において、上記領域Ｒ１における錫の平均含有量が、上記領域Ｒ２における錫の平均含有量より大きいことが好ましい。このような濃度差及び濃度勾配の存在により、酸の存在下に晒された後の接続抵抗をより一層低くすることができ、高温かつ高湿な環境下で導電性粒子が高電圧に長時間曝されても、Ｎｉ－Ｓｎ導電層における電荷の移動をより一層効果的に防ぐことができる。 The conductive particles preferably have different tin contents such that the tin content in the region R1 is higher than the tin content in the region R2 in the Ni—Sn conductive layer. It is preferable that the content has a gradient. In the Ni--Sn conductive layer, it is preferable that tin is unevenly distributed so that it is present more in the region R1 than in the region R2. In the Ni—Sn conductive layer, the average tin content in the region R1 is preferably larger than the average tin content in the region R2. The presence of such a concentration difference and concentration gradient can further reduce the connection resistance after exposure to the presence of acid, and the conductive particles can be exposed to high voltage for a long time in a hot and humid environment. Even if exposed to the Ni--Sn conductive layer, movement of charges in the Ni--Sn conductive layer can be more effectively prevented.
　本発明の効果をより一層効果的に発揮する観点からは、上記領域Ｒ１の全体１００重量％中、上記領域Ｒ１における錫の平均含有量は、好ましくは０．５重量％以上、より好ましくは１．０重量％以上、さらに好ましくは３．０重量％以上であり、好ましくは１０重量％以下、より好ましくは９．０重量％以下、さらに好ましくは８．０重量％以下である。 From the viewpoint of exhibiting the effects of the present invention even more effectively, the average content of tin in the region R1 is preferably 0.5% by weight or more, more preferably 1% by weight, based on 100% by weight of the entire region R1. The content is at least .0% by weight, more preferably at least 3.0% by weight, preferably at most 10% by weight, more preferably at most 9.0% by weight, even more preferably at most 8.0% by weight.
　本発明の効果をより一層効果的に発揮する観点からは、上記領域Ｒ２の全体１００重量％中、上記領域Ｒ２における錫の平均含有量は、好ましくは１０重量％以下、より好ましくは５重量％以下、さらに好ましくは３重量％以下である。上記領域Ｒ２の全体１００重量％中、上記領域Ｒ２における錫の平均含有量の下限は、特に限定されない。上記領域Ｒ２の全体１００重量％中、上記領域Ｒ２における錫の平均含有量は、３重量％以上であってもよい。 From the viewpoint of exhibiting the effects of the present invention even more effectively, the average content of tin in the region R2 is preferably 10% by weight or less, more preferably 5% by weight, based on the entire 100% by weight of the region R2. The content is preferably 3% by weight or less. The lower limit of the average content of tin in the region R2 in 100% by weight of the entire region R2 is not particularly limited. The average content of tin in the region R2 may be 3% by weight or more out of 100% by weight of the entire region R2.
　本発明に係る導電性粒子では、上記Ｎｉ－Ｓｎ導電層に含まれる錫の厚み方向における分布を制御することが、非常に重要である。 In the conductive particles according to the present invention, it is very important to control the distribution of tin contained in the Ni--Sn conductive layer in the thickness direction.
　ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記Ｎｉ－Ｓｎ導電層の全体に含まれる錫の合計１００重量％中、上記領域Ｒ１における錫の含有量は、好ましくは６５重量％以上、より好ましくは７０重量％以上、より一層好ましくは８０重量％以上である。本発明の効果をより一層効果的に発揮する観点からは、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、上記Ｎｉ－Ｓｎ導電層の全体に含まれる錫の合計１００重量％中の８０重量％以上の錫が含まれることが好ましい。上記Ｎｉ－Ｓｎ導電層の全体に含まれる錫の合計１００重量％中、上記領域Ｒ１における錫の含有量は、さらに好ましくは８５重量％以上、さらに一層好ましくは９０重量％以上、特に好ましくは９５重量％以上、最も好ましくは１００重量％（全量）である。上記Ｎｉ－Ｓｎ導電層の全体に含まれる錫の合計１００重量％中、上記領域Ｒ１における錫の含有量が、上記下限以上であると、酸の存在下に晒された後の接続抵抗をより一層低くすることができ、高温かつ高湿な環境下で導電性粒子が高電圧に長時間曝されても、Ｎｉ－Ｓｎ導電層における電荷の移動をより一層効果的に防ぐことができる。 When the content of tin in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the content of tin in the region R1 is out of the total 100% by weight of tin contained in the entire Ni-Sn conductive layer. The amount is preferably 65% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more. From the viewpoint of exhibiting the effects of the present invention even more effectively, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the outer thickness of the Ni-Sn conductive layer It is preferable that the 1/2 region (R1) contains 80% by weight or more of tin out of the total 100% by weight of tin contained in the entire Ni--Sn conductive layer. The content of tin in the region R1 is more preferably 85% by weight or more, even more preferably 90% by weight or more, particularly preferably 95% by weight or more, out of the total 100% by weight of tin contained in the entire Ni--Sn conductive layer. % by weight or more, most preferably 100% by weight (total amount). If the content of tin in the region R1 is equal to or higher than the lower limit of the total 100% by weight of tin contained in the entire Ni-Sn conductive layer, the connection resistance after being exposed to the presence of an acid will be increased. Even if the conductive particles are exposed to high voltage for a long time in a high temperature and high humidity environment, the transfer of charges in the Ni--Sn conductive layer can be even more effectively prevented.
　本発明の効果をより一層効果的に発揮する観点からは、上記導電性粒子では、上記Ｎｉ－Ｓｎ導電層の厚み１００％中、錫を含む領域の割合は、好ましくは５％以上、より好ましくは１５％以上であり、好ましくは９５％以下、より好ましくは８０％以下、さらに好ましくは５０％以下である。本発明の効果をより一層効果的に発揮する観点からは、上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、上記Ｎｉ－Ｓｎ導電層の厚み１５％以上の領域において、錫が含まれることが好ましい。従来の導電性粒子では、ＴＥＭ－ＥＤＸにより導電層の厚み方向における錫の含有量を測定したときに、該導電層の厚み１００％中、錫を含む領域の割合は、１０％程度である。本発明に係る導電性粒子において、上記Ｎｉ－Ｓｎ導電層の厚み１００％中、錫を含む領域の割合が上記下限以上及び上記上限以下であると、酸の存在下に晒された後の接続抵抗をより一層低くすることができ、高温かつ高湿な環境下で導電性粒子が高電圧に長時間曝されても、Ｎｉ－Ｓｎ導電層における電荷の移動をより一層効果的に防ぐことができる。 From the viewpoint of exhibiting the effects of the present invention even more effectively, in the conductive particles, the proportion of the area containing tin in 100% of the thickness of the Ni--Sn conductive layer is preferably 5% or more, more preferably is 15% or more, preferably 95% or less, more preferably 80% or less, even more preferably 50% or less. From the viewpoint of exhibiting the effects of the present invention even more effectively, in the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the Ni-Sn Preferably, tin is contained in a region where the conductive layer has a thickness of 15% or more. In conventional conductive particles, when the tin content in the thickness direction of the conductive layer is measured by TEM-EDX, the proportion of the area containing tin in 100% of the thickness of the conductive layer is about 10%. In the conductive particles according to the present invention, when the proportion of the area containing tin in 100% of the thickness of the Ni-Sn conductive layer is equal to or more than the above-mentioned lower limit and below the above-mentioned upper limit, the connection after being exposed to the presence of acid is The resistance can be lowered even further, and even if the conductive particles are exposed to high voltage for a long time in a high temperature and high humidity environment, the transfer of charge in the Ni-Sn conductive layer can be more effectively prevented. can.
　本発明に係る導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、錫を含む領域の厚み（分布曲線におけるピーク幅）と、該領域における錫の含有量の最大値（分布曲線におけるピーク高さ）との関係を制御することが、非常に重要である。すなわち、上記導電性粒子では、ＴＥＭ－ＥＤＸにより測定した錫の含有量の分布曲線において、横軸を上記Ｎｉ－Ｓｎ導電層の厚みを１００％としたときの外表面からの厚み方向の距離（％）とし、縦軸を錫の含有量（重量％）としたときに、分布曲線のピーク幅とピーク高さとを制御することが、非常に重要である。 In the conductive particles according to the present invention, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the thickness of the area containing tin (peak width in the distribution curve) and the area It is very important to control the relationship between the maximum value of tin content (peak height in the distribution curve) and the maximum tin content (peak height in the distribution curve). That is, in the conductive particles, in the tin content distribution curve measured by TEM-EDX, the distance in the thickness direction from the outer surface when the horizontal axis is the thickness of the Ni-Sn conductive layer as 100% ( %) and the vertical axis is the tin content (weight %), it is very important to control the peak width and peak height of the distribution curve.
　上記錫の含有量の分布曲線の形状は、山型であってもよく、山型の一部分であってもよい。上記錫の含有量の分布曲線は、単峰性であってもよく、多峰性であってもよい。上記錫の含有量の分布曲線は、１つのピークを有していてもよく、複数のピークを有していてもよい。上記錫の含有量の分布曲線が複数のピークを有している場合に、上記Ｎｉ－Ｓｎ導電層の厚み１００％中、錫を含む領域の割合は、各ピーク幅の合計である。なお、上記錫の含有量の分布曲線は、１つのピークを有することが好ましく、上述した通り、該ピーク（上記Ｎｉ－Ｓｎ導電層の錫の含有量の最大値）は、上記領域Ｒ１に存在することが好ましく、上記Ｎｉ－Ｓｎ導電層の最表面に存在することがより好ましい。 The shape of the tin content distribution curve may be a mountain shape or a portion of a mountain shape. The tin content distribution curve may be unimodal or multimodal. The tin content distribution curve may have one peak or a plurality of peaks. When the tin content distribution curve has a plurality of peaks, the proportion of the area containing tin in 100% of the thickness of the Ni--Sn conductive layer is the sum of the widths of each peak. The distribution curve of the tin content preferably has one peak, and as described above, the peak (the maximum value of the tin content of the Ni--Sn conductive layer) is present in the region R1. It is preferred that the Ni--Sn conductive layer be present on the outermost surface of the Ni--Sn conductive layer.
　上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、錫が上記Ｎｉ－Ｓｎ導電層の厚み方向において広い領域に分布し、かつ上記Ｎｉ－Ｓｎ導電層の錫の含有量の最大値が小さくてもよい。上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、錫が上記Ｎｉ－Ｓｎ導電層の厚み方向において広い領域に分布し、かつ上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、錫の含有量の最大値が小さくてもよい。また、上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、錫が上記Ｎｉ－Ｓｎ導電層の厚み方向において狭い領域に分布し、かつ錫の含有量の最大値が大きくてもよい。上記導電性粒子では、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、錫が上記Ｎｉ－Ｓｎ導電層の厚み方向において狭い領域に分布し、かつ上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、錫の含有量の最大値が大きくてもよい。 In the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, it is found that tin is distributed over a wide area in the thickness direction of the Ni-Sn conductive layer, and The maximum value of the tin content in the Ni--Sn conductive layer may be small. In the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, it is found that tin is distributed over a wide area in the thickness direction of the Ni-Sn conductive layer, and In the outer half-thickness region (R1) of the Ni—Sn conductive layer, the maximum value of the tin content may be small. Further, in the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, tin is distributed in a narrow region in the thickness direction of the Ni-Sn conductive layer, Moreover, the maximum value of the tin content may be large. In the conductive particles, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, tin is distributed in a narrow region in the thickness direction of the Ni-Sn conductive layer, and In the outer half-thickness region (R1) of the Ni—Sn conductive layer, the maximum value of the tin content may be large.
　錫が上記Ｎｉ－Ｓｎ導電層の厚み方向において広い領域に分布し、かつ上記Ｎｉ－Ｓｎ導電層の錫の含有量の最大値（上記領域Ｒ１における錫の含有量の最大値）が小さい場合には、上記Ｎｉ－Ｓｎ導電層の厚み１００％中、錫を含む領域の割合は、特に好ましくは２０％以上、最も好ましくは２５％以上である。また、上記の場合には、上記Ｎｉ－Ｓｎ導電層の厚み１００％中、錫を含む領域の割合は、特に好ましくは５０％以下、最も好ましくは４０％以下である。上記の場合に、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定する。この測定において、上記Ｎｉ－Ｓｎ導電層の厚み１０％以上かつ５０％未満の領域において、５重量％以上の含有量で錫が含まれることが好ましい。上記の測定において、錫の含有量が５重量％以上である領域は、上記Ｎｉ－Ｓｎ導電層の厚み１００％中、好ましくは８％以上、より好ましくは１０％以上、さらに好ましくは１２．５％以上であり、好ましくは５０％未満、より好ましくは４０％以下、さらに好ましくは３０％以下である。また、上記の場合に、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定する。この測定において、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、錫の含有量の最大値は、５重量％以上、好ましくは７重量％以上、より好ましくは１０重量％以上であり、好ましくは５０重量％以下、より好ましくは４０重量％以下、さらに好ましくは３０重量％以下、特に好ましくは２０重量％以下である。なお、上記の測定において、上記Ｎｉ－Ｓｎ導電層の厚み１０％以上かつ５０％未満％以上の領域において、５重量％以上の含有量で錫が含まれ、かつ、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、錫の含有量の最大値が、５重量％以上４０重量％以下であることがより好ましい。 When tin is distributed over a wide region in the thickness direction of the Ni--Sn conductive layer, and the maximum value of the tin content in the Ni--Sn conductive layer (the maximum value of the tin content in the region R1) is small; The proportion of the area containing tin in the 100% thickness of the Ni--Sn conductive layer is particularly preferably 20% or more, most preferably 25% or more. Further, in the above case, the proportion of the area containing tin in the 100% thickness of the Ni--Sn conductive layer is particularly preferably 50% or less, most preferably 40% or less. In the above case, the tin content in the thickness direction of the Ni--Sn conductive layer is measured by TEM-EDX. In this measurement, it is preferable that tin is contained in a content of 5% by weight or more in a region where the thickness of the Ni--Sn conductive layer is 10% or more and less than 50%. In the above measurement, the area where the tin content is 5% by weight or more is preferably 8% or more, more preferably 10% or more, and even more preferably 12.5% of the 100% thickness of the Ni-Sn conductive layer. % or more, preferably less than 50%, more preferably 40% or less, even more preferably 30% or less. Further, in the above case, the tin content in the thickness direction of the Ni--Sn conductive layer is measured by TEM-EDX. In this measurement, the maximum tin content in the outer 1/2 thickness region (R1) of the Ni-Sn conductive layer is 5% by weight or more, preferably 7% by weight or more, more preferably 10% by weight. % or more, preferably 50% by weight or less, more preferably 40% by weight or less, still more preferably 30% by weight or less, particularly preferably 20% by weight or less. In addition, in the above measurement, tin is contained at a content of 5% by weight or more in a region where the thickness of the Ni-Sn conductive layer is 10% or more and less than 50%, and the thickness of the Ni-Sn conductive layer is In the outer half-thickness region (R1), the maximum tin content is more preferably 5% by weight or more and 40% by weight or less.
　錫が上記Ｎｉ－Ｓｎ導電層の厚み方向において狭い領域に分布し、かつ上記Ｎｉ－Ｓｎ導電層の錫の含有量の最大値（上記領域Ｒ１における錫の含有量の最大値）が大きい場合には、上記Ｎｉ－Ｓｎ導電層の厚み１００％中、錫を含む領域の割合は、特に好ましくは５％以上、最も好ましくは１０％以上である。また、上記の場合には、上記Ｎｉ－Ｓｎ導電層の厚み１００％中、錫を含む領域の割合は、さらに好ましくは４０％以下、特に好ましくは３０％以下、最も好ましくは２５％以下である。上記の場合に、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定する。この測定において、上記Ｎｉ－Ｓｎ導電層の厚み３０％以下の領域において、５重量％以上の含有量で錫が含まれることが好ましい。上記の測定において、錫の含有量が５重量％以上である領域は、上記Ｎｉ－Ｓｎ導電層の厚み１００％中、好ましくは０．１％以上、より好ましくは０．５％以上、さらに好ましくは１．０％以上であり、好ましくは３０％以下、より好ましくは２５％以下、さらに好ましくは２０％以下、最も好ましくは１０％以下である。また、上記の場合に、ＴＥＭ－ＥＤＸにより上記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定する。この測定において、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、錫の含有量の最大値は、５重量％以上、好ましくは１０重量％以上、より好ましくは１５重量％以上である。また、この測定において、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、錫の含有量の最大値は、好ましくは９５重量％以下、より好ましくは９０重量％以下、さらに好ましくは８０重量％以下、特に好ましくは５０重量％以下、最も好ましくは４０重量％以下である。なお、上記の測定において、上記Ｎｉ－Ｓｎ導電層の厚み３０％以下の領域において、錫の含有量が５重量％以上であり、かつ、上記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域（Ｒ１）において、錫の含有量の最大値が、１０重量％以上であることがより好ましい。 When tin is distributed in a narrow region in the thickness direction of the Ni-Sn conductive layer and the maximum value of the tin content in the Ni-Sn conductive layer (the maximum value of the tin content in the region R1) is large; The proportion of the area containing tin in the 100% thickness of the Ni--Sn conductive layer is particularly preferably 5% or more, most preferably 10% or more. In the above case, the proportion of the area containing tin in the 100% thickness of the Ni--Sn conductive layer is more preferably 40% or less, particularly preferably 30% or less, and most preferably 25% or less. . In the above case, the tin content in the thickness direction of the Ni--Sn conductive layer is measured by TEM-EDX. In this measurement, it is preferable that tin is contained in a content of 5% by weight or more in a region where the thickness of the Ni--Sn conductive layer is 30% or less. In the above measurement, the area where the tin content is 5% by weight or more is preferably 0.1% or more, more preferably 0.5% or more, and even more preferably is 1.0% or more, preferably 30% or less, more preferably 25% or less, even more preferably 20% or less, and most preferably 10% or less. Further, in the above case, the tin content in the thickness direction of the Ni--Sn conductive layer is measured by TEM-EDX. In this measurement, the maximum tin content in the outer 1/2 thickness region (R1) of the Ni-Sn conductive layer is 5% by weight or more, preferably 10% by weight or more, and more preferably 15% by weight. % or more. In addition, in this measurement, in the outer 1/2 thickness region (R1) of the Ni--Sn conductive layer, the maximum value of the tin content is preferably 95% by weight or less, more preferably 90% by weight or less, It is more preferably 80% by weight or less, particularly preferably 50% by weight or less, most preferably 40% by weight or less. In addition, in the above measurement, the tin content is 5% by weight or more in the area where the thickness of the Ni-Sn conductive layer is 30% or less, and the tin content is 5% by weight or more in the area where the thickness of the Ni-Sn conductive layer is 1/2 In region (R1), the maximum tin content is more preferably 10% by weight or more.
　上記領域Ｒ１におけるニッケル及び錫の平均含有量、上記領域Ｒ２におけるニッケル及び錫の平均含有量、上記領域Ｒ１における錫の含有量の最大値、及び上記領域Ｒ２における錫の含有量の最大値は、ＴＥＭ－ＥＤＸにより測定することができる。具体的に、集束イオンビームを用いて、上記導電性粒子の薄膜切片を作製する。次いで、透過型電子顕微鏡ＦＥ－ＴＥＭ（日本電子社製「ＪＥＭ－２０１０ＦＥＦ」）を用いて、エネルギー分散型Ｘ線分析装置（ＥＤＳ）により、Ｎｉ－Ｓｎ導電層の厚み方向におけるニッケル及び錫の各含有量を測定する。なお、得られる重量分析図において、Ｎｉ－Ｓｎ導電層に含まれる全ての金属の含有量を示す曲線上の変曲点のうち、最も外側の変曲点をＮｉ－Ｓｎ導電層の厚み方向の起点（厚み０％）とし、最も内側の変曲点をＮｉ－Ｓｎ導電層の厚み方向の終点（厚み１００％）とする。 The average content of nickel and tin in the region R1, the average content of nickel and tin in the region R2, the maximum value of the tin content in the region R1, and the maximum value of the tin content in the region R2 are as follows: It can be measured by TEM-EDX. Specifically, a thin film section of the conductive particles is produced using a focused ion beam. Next, using a transmission electron microscope FE-TEM ("JEM-2010FEF" manufactured by JEOL Ltd.) and an energy dispersive X-ray spectrometer (EDS), each of nickel and tin was measured in the thickness direction of the Ni-Sn conductive layer. Measure the content. In addition, in the obtained gravimetric analysis diagram, the outermost inflection point on the curve showing the content of all metals contained in the Ni-Sn conductive layer is The starting point (thickness 0%) is taken as the innermost inflection point and the end point (thickness 100%) in the thickness direction of the Ni--Sn conductive layer.
　上記Ｎｉ－Ｓｎ導電層は、ニッケルと、錫と、ニッケル及び錫以外の金属とを含んでいてもよい。上記ニッケル及び錫以外の金属としては、銀、銅、白金、亜鉛、鉄、鉛、アルミニウム、コバルト、インジウム、パラジウム、クロム、チタン、アンチモン、ビスマス、タリウム、ゲルマニウム、カドミウム、ケイ素、タングステン、モリブデン及び錫ドープ酸化インジウム（ＩＴＯ）等が挙げられる。これらの金属は、１種のみが用いられてもよく、２種以上が併用されてもよい。 The Ni—Sn conductive layer may contain nickel, tin, and a metal other than nickel and tin. Metals other than nickel and tin include silver, copper, platinum, zinc, iron, lead, aluminum, cobalt, indium, palladium, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, silicon, tungsten, molybdenum, and Examples include tin-doped indium oxide (ITO). These metals may be used alone or in combination of two or more.
　上記Ｎｉ－Ｓｎ導電層の全体の領域における上記ニッケル及び錫以外の金属の平均含有量は、好ましくは１０重量％以下、より好ましくは５重量％以下、さらに好ましくは３重量％以下である。上記Ｎｉ－Ｓｎ導電層の全体の領域における上記ニッケル及び錫以外の金属の平均含有量の下限は、特に限定されない。上記Ｎｉ－Ｓｎ導電層の全体の領域における上記ニッケル及び錫以外の金属の平均含有量は、０．０１重量％以上であってもよく、０．１重量％以上であってもよい。 The average content of metals other than nickel and tin in the entire area of the Ni--Sn conductive layer is preferably 10% by weight or less, more preferably 5% by weight or less, and even more preferably 3% by weight or less. The lower limit of the average content of metals other than nickel and tin in the entire area of the Ni--Sn conductive layer is not particularly limited. The average content of the metal other than nickel and tin in the entire area of the Ni--Sn conductive layer may be 0.01% by weight or more, or 0.1% by weight or more.
　なお、上記Ｎｉ－Ｓｎ導電層が、上記ニッケル及び錫以外の金属を含む場合に、上記領域Ｒ１及び上記領域Ｒ２におけるニッケルの平均含有量及び錫の平均含有量は、ニッケルの含有量と錫の含有量との合計を１００重量％として算出する。 In addition, when the Ni-Sn conductive layer contains a metal other than the nickel and tin, the average nickel content and the average tin content in the region R1 and the region R2 are the same as the nickel content and the tin content. The total amount including the content is calculated as 100% by weight.
　上記Ｎｉ－Ｓｎ導電層の厚みは、好ましくは５ｎｍ以上、より好ましくは１０ｎｍ以上、さらに好ましくは８０ｎｍ以上であり、好ましくは５００ｎｍ以下、より好ましくは３００ｎｍ以下である。上記Ｎｉ－Ｓｎ導電層の厚みが上記下限以上及び上記上限以下であると、接続抵抗をより一層低くすることができる。上記Ｎｉ－Ｓｎ導電層の厚みは、導電性粒子におけるＮｉ－Ｓｎ導電層の平均厚みを示す。 The thickness of the Ni--Sn conductive layer is preferably 5 nm or more, more preferably 10 nm or more, even more preferably 80 nm or more, and preferably 500 nm or less, more preferably 300 nm or less. When the thickness of the Ni—Sn conductive layer is at least the above lower limit and at most the above upper limit, connection resistance can be further reduced. The thickness of the Ni--Sn conductive layer mentioned above indicates the average thickness of the Ni--Sn conductive layer in the conductive particles.
　上記Ｎｉ－Ｓｎ導電層を形成する方法は特に限定されない。上記Ｎｉ－Ｓｎ導電層を形成する方法としては、例えば、無電解めっきによる方法、電気めっきによる方法、物理的蒸着による方法、並びに金属粉末もしくは金属粉末とバインダーとを含むペーストを粒子の表面にコーティングする方法等が挙げられる。なかでも、上記Ｎｉ－Ｓｎ導電層の形成が簡便であるので、無電解めっきによる方法が好ましい。上記物理的蒸着による方法としては、真空蒸着、イオンプレーティング及びイオンスパッタリング等の方法が挙げられる。 The method for forming the Ni--Sn conductive layer is not particularly limited. Methods for forming the Ni-Sn conductive layer include, for example, electroless plating, electroplating, physical vapor deposition, and coating the surfaces of particles with metal powder or a paste containing metal powder and a binder. Examples include a method to do so. Among these, a method using electroless plating is preferred because the formation of the Ni--Sn conductive layer is simple. Examples of the physical vapor deposition method include vacuum vapor deposition, ion plating, and ion sputtering.
　上記Ｎｉ－Ｓｎ導電層におけるニッケル、及び錫の含有量及び分布を制御する方法としては、例えば、無電解めっきにおいて、めっき液中の錫及び錯化剤の濃度を調整する方法、及び反応液のｐＨを調整する方法等が挙げられる。 Methods for controlling the content and distribution of nickel and tin in the Ni-Sn conductive layer include, for example, a method of adjusting the concentration of tin and a complexing agent in the plating solution in electroless plating, and a method of controlling the concentration of tin and complexing agent in the plating solution, and Examples include a method of adjusting pH.
　上記導電性粒子は、複数の導電層を備えていてもよい。上記導電性粒子は、上記Ｎｉ－Ｓｎ導電層以外の導電層（他の導電層）を備えていてもよい。上記導電性粒子が複数の導電層を備える場合、上記Ｎｉ－Ｓｎ導電層は、上記導電性粒子の最外層であることが好ましい。上記導電性粒子が複数の導電層を備える場合、上記Ｎｉ－Ｓｎ導電層は、最外層の導電層であることが好ましい。 The above-mentioned conductive particles may include multiple conductive layers. The conductive particles may include a conductive layer (another conductive layer) other than the Ni—Sn conductive layer. When the conductive particles include a plurality of conductive layers, the Ni—Sn conductive layer is preferably the outermost layer of the conductive particles. When the conductive particles include a plurality of conductive layers, the Ni—Sn conductive layer is preferably the outermost conductive layer.
　上記Ｎｉ－Ｓｎ導電層以外の導電層の構成は、特に限定されない。上記Ｎｉ－Ｓｎ導電層以外の導電層の材料は、上記Ｎｉ－Ｓｎ導電層の材料と同一であってもよく、異なっていてもよい。 The structure of the conductive layers other than the Ni--Sn conductive layer is not particularly limited. The material of the conductive layers other than the Ni--Sn conductive layer may be the same as or different from the material of the Ni--Sn conductive layer.
　本発明に係る導電性粒子は、表面に突起を有することが好ましい。上記Ｎｉ－Ｓｎ導電層は、外表面に突起を有することが好ましい。導電性粒子により接続される電極の表面には、酸化被膜が形成されていることが多い。導電性の突起を有する導電性粒子の使用により、電極間に導電性粒子を配置した後、圧着させることにより、突起により酸化被膜が効果的に排除される。このため、電極と導電性粒子とをより一層確実に接触させることができ、電極間の接続抵抗をより一層低くすることができる。さらに、導電性粒子が表面に絶縁性物質を有する場合、又は導電性粒子が樹脂中に分散されて導電材料として用いられる場合に、導電性粒子の突起によって、導電性粒子と電極との間の絶縁性物質又は樹脂を効果的に排除できる。このため、電極間の導通信頼性を高めることができる。 The conductive particles according to the present invention preferably have protrusions on the surface. The Ni--Sn conductive layer preferably has protrusions on its outer surface. An oxide film is often formed on the surface of an electrode connected by conductive particles. By using conductive particles having conductive protrusions, the protrusions effectively eliminate the oxide film by crimping the conductive particles after placing them between the electrodes. Therefore, the electrodes and the conductive particles can be brought into contact with each other more reliably, and the connection resistance between the electrodes can be further lowered. Furthermore, when the conductive particles have an insulating substance on their surface, or when the conductive particles are dispersed in a resin and used as a conductive material, the protrusions of the conductive particles create a gap between the conductive particles and the electrode. Insulating materials or resins can be effectively eliminated. Therefore, the reliability of conduction between the electrodes can be improved.
　上記突起は複数であることが好ましい。上記導電性粒子１個当たりの上記導電層の外表面の突起は、好ましくは３個以上、より好ましくは５個以上である。上記突起の数の上限は特に限定されない。上記突起の数は、好ましくは１０００個以下、より好ましくは８００個以下である。突起の数の上限は導電性粒子の粒子径等を考慮して適宜選択できる。 It is preferable that the number of the protrusions is plural. The number of protrusions on the outer surface of the conductive layer per conductive particle is preferably 3 or more, more preferably 5 or more. The upper limit of the number of projections is not particularly limited. The number of the protrusions is preferably 1000 or less, more preferably 800 or less. The upper limit of the number of protrusions can be appropriately selected in consideration of the particle diameter of the conductive particles, etc.
　複数の上記突起の平均高さは、好ましくは０．００１μｍ以上、より好ましくは０．０５μｍ以上、好ましくは０．９μｍ以下、より好ましくは０．２μｍ以下である。上記突起の平均高さが上記下限以上及び上記上限以下であると、電極間の接続抵抗が効果的に低くなる。上記突起の平均高さは、以下の方法で算出できる。本発明の導電性粒子５０個を電子顕微鏡又は光学顕微鏡にて観察し、観察された導電性粒子の周縁部の突起全ての高さを測定する。突起が形成されていない面を基準表面として凸部の高さを測定し、平均値を算出することにより求められる。 The average height of the plurality of protrusions is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. When the average height of the protrusions is equal to or greater than the lower limit and equal to or less than the upper limit, the connection resistance between the electrodes is effectively reduced. The average height of the protrusions can be calculated by the following method. Fifty conductive particles of the present invention are observed using an electron microscope or an optical microscope, and the heights of all the protrusions on the periphery of the observed conductive particles are measured. It is determined by measuring the height of the convex portion using a surface on which no protrusions are formed as a reference surface, and calculating the average value.
　本発明の効果をより一層効果的に発揮する観点からは、上記Ｎｉ－Ｓｎ導電層の外表面の全表面積１００％中、上記突起がある部分の表面積は好ましくは１０％以上、より好ましくは２０％以上、さらに好ましくは３０％以上である。上記Ｎｉ－Ｓｎ導電層の外表面の全表面積１００％中、上記突起がある部分の表面積の占める割合の上限は特に限定されないが、通常１００％以下、好ましくは９９％以下である。 From the viewpoint of exhibiting the effects of the present invention even more effectively, the surface area of the portion with the protrusions is preferably 10% or more, more preferably 20% of the total surface area of the outer surface of the Ni-Sn conductive layer. % or more, more preferably 30% or more. The upper limit of the ratio of the surface area of the portion with the protrusions to 100% of the total surface area of the outer surface of the Ni--Sn conductive layer is not particularly limited, but is usually 100% or less, preferably 99% or less.
　上記突起がある部分の表面積の比率は、以下の方法で算出できる。本発明の導電性粒子５０個を電子顕微鏡又は光学顕微鏡にて観察し、正投影面において突起として現れている部分の面積の比率を測定し、平均値を算出することにより求められる。 The ratio of the surface area of the portion where the protrusion is present can be calculated by the following method. It is determined by observing 50 conductive particles of the present invention with an electron microscope or an optical microscope, measuring the ratio of the areas of the portions appearing as protrusions in the orthogonal projection plane, and calculating the average value.
　（芯物質）
　上記芯物質が上記Ｎｉ－Ｓｎ導電層中に埋め込まれていることによって、上記Ｎｉ－Ｓｎ導電層が外表面に複数の突起を有するようにすることが容易である。但し、導電性粒子及びＮｉ－Ｓｎ導電層の外表面に突起を形成するために、芯物質を必ずしも用いなくてもよく、芯物質を用いないことが好ましい。上記導電性粒子は、上記Ｎｉ－Ｓｎ導電層の内部及び内側に、上記Ｎｉ－Ｓｎ導電部の外表面を***させるための芯物質を有さないことが好ましい。上記Ｎｉ－Ｓｎ導電層が、上記Ｎｉ－Ｓｎ導電層の内部及び内側に、上記Ｎｉ－Ｓｎ導電層の外表面を***させるための芯物質を含まないことが好ましい。 (core substance)
Since the core material is embedded in the Ni--Sn conductive layer, it is easy to make the Ni--Sn conductive layer have a plurality of protrusions on its outer surface. However, in order to form protrusions on the outer surfaces of the conductive particles and the Ni--Sn conductive layer, it is not necessary to use a core material, and it is preferable not to use a core material. Preferably, the conductive particles do not have a core material inside and inside the Ni--Sn conductive layer for raising the outer surface of the Ni--Sn conductive part. Preferably, the Ni--Sn conductive layer does not include a core material inside and inside the Ni--Sn conductive layer for raising the outer surface of the Ni--Sn conductive layer.
　上記突起を形成する方法としては、基材粒子の表面に芯物質を付着させた後、無電解めっきによりＮｉ－Ｓｎ導電層を形成する方法、並びに基材粒子の表面に無電解めっきによりＮｉ－Ｓｎ導電層を形成した後、芯物質を付着させ、さらに無電解めっきによりＮｉ－Ｓｎ導電層を形成する方法等が挙げられる。上記突起を形成する他の方法としては、基材粒子の表面上にＮｉ－Ｓｎ導電層を形成する途中段階で、芯物質を添加する方法等が挙げられる。 The above protrusions can be formed by attaching a core substance to the surface of the base particle and then forming a Ni-Sn conductive layer by electroless plating, or by electroless plating the Ni-Sn conductive layer on the surface of the base particle. Examples include a method of forming a Sn conductive layer, then depositing a core material, and further forming a Ni--Sn conductive layer by electroless plating. Other methods for forming the protrusions include a method of adding a core material during the formation of the Ni--Sn conductive layer on the surface of the base material particles.
　上記基材粒子の表面上に芯物質を配置する方法としては、例えば、基材粒子の分散液中に、芯物質を添加し、基材粒子の表面に芯物質を、例えば、ファンデルワールス力により集積させ、付着させる方法、並びに基材粒子を入れた容器に、芯物質を添加し、容器の回転等による機械的な作用により基材粒子の表面に芯物質を付着させる方法等が挙げられる。なかでも、付着させる芯物質の量を制御しやすいため、分散液中の基材粒子の表面に芯物質を集積させ、付着させる方法が好ましい。 As a method for arranging the core material on the surface of the base material particles, for example, the core material is added to a dispersion of the base material particles, and the core material is applied to the surface of the base material particles by, for example, van der Waals force. methods of accumulating and adhering the base particles, and methods of adding a core substance to a container containing the base particles and attaching the core substance to the surface of the base particles through mechanical action such as rotation of the container. . Among these, a method of accumulating and depositing the core material on the surface of the base particles in the dispersion is preferred because it is easy to control the amount of the core material to be deposited.
　上記芯物質を構成する物質としては、導電性物質及び非導電性物質が挙げられる。上記導電性物質としては、例えば、金属、金属の酸化物、黒鉛等の導電性非金属及び導電性ポリマー等が挙げられる。上記導電性ポリマーとしては、ポリアセチレン等が挙げられる。上記非導電性物質としては、シリカ、アルミナ、チタン酸バリウム及びジルコニア等が挙げられる。なかでも、導電性を高めることができ、さらに接続抵抗を効果的に低くすることができるので、金属が好ましい。上記芯物質は金属粒子であることが好ましい。 Examples of the substance constituting the core substance include conductive substances and non-conductive substances. Examples of the conductive substance include metals, metal oxides, conductive nonmetals such as graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene. Examples of the non-conductive substance include silica, alumina, barium titanate, and zirconia. Among these, metal is preferred because it can improve conductivity and effectively lower connection resistance. Preferably, the core material is a metal particle.
　上記金属としては、例えば、金、銀、銅、白金、亜鉛、鉄、鉛、錫、アルミニウム、コバルト、インジウム、ニッケル、クロム、チタン、アンチモン、ビスマス、ゲルマニウム及びカドミウム等の金属、並びに錫－鉛合金、錫－銅合金、錫－銀合金、錫－鉛－銀合金及び炭化タングステン等の２種類以上の金属で構成される合金等が挙げられる。なかでも、ニッケル、銅、銀又は金が好ましい。上記芯物質を形成するための金属は、上記導電層を形成するための金属と同じであってもよく、異なっていてもよい。上記芯物質を形成するための金属は、上記導電層を形成するための金属を含むことが好ましい。上記芯物質を形成するための金属は、ニッケルを含むことが好ましい。 Examples of the above metals include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, and cadmium, and tin-lead. Examples include alloys composed of two or more metals, such as alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and tungsten carbide. Among them, nickel, copper, silver or gold is preferred. The metal for forming the core material may be the same as or different from the metal for forming the conductive layer. The metal for forming the core material preferably includes the metal for forming the conductive layer. The metal for forming the core material preferably contains nickel.
　上記芯物質の材料の具体例としては、チタン酸バリウム（モース硬度４．５）、ニッケル（モース硬度５）、シリカ（二酸化珪素、モース硬度６～７）、酸化チタン（モース硬度７）、ジルコニア（モース硬度８～９）、アルミナ（モース硬度９）、炭化タングステン（モース硬度９）及びダイヤモンド（モース硬度１０）等が挙げられる。上記無機粒子は、ニッケル、シリカ、酸化チタン、ジルコニア、アルミナ、炭化タングステン又はダイヤモンドであることが好ましく、シリカ、酸化チタン、ジルコニア、アルミナ、炭化タングステン又はダイヤモンドであることがより好ましい。上記無機粒子は、酸化チタン、ジルコニア、アルミナ、炭化タングステン又はダイヤモンドであることがさらに好ましく、ジルコニア、アルミナ、炭化タングステン又はダイヤモンドであることが特に好ましい。上記芯物質の材料のモース硬度は好ましくは５以上、より好ましくは６以上、さらに好ましくは７以上、特に好ましくは７．５以上である。 Specific examples of the materials for the core substance include barium titanate (Mohs hardness 4.5), nickel (Mohs hardness 5), silica (silicon dioxide, Mohs hardness 6-7), titanium oxide (Mohs hardness 7), zirconia (Mohs hardness: 8 to 9), alumina (Mohs hardness: 9), tungsten carbide (Mohs hardness: 9), and diamond (Mohs hardness: 10). The inorganic particles are preferably nickel, silica, titanium oxide, zirconia, alumina, tungsten carbide, or diamond, and more preferably silica, titanium oxide, zirconia, alumina, tungsten carbide, or diamond. The inorganic particles are more preferably titanium oxide, zirconia, alumina, tungsten carbide, or diamond, and particularly preferably zirconia, alumina, tungsten carbide, or diamond. The Mohs hardness of the material of the core substance is preferably 5 or more, more preferably 6 or more, still more preferably 7 or more, particularly preferably 7.5 or more.
　上記芯物質の形状は特に限定されない。芯物質の形状は塊状であることが好ましい。芯物質としては、例えば、粒子状の塊、複数の微小粒子が凝集した凝集塊、及び不定形の塊等が挙げられる。 The shape of the core material is not particularly limited. The shape of the core material is preferably a block. Examples of the core substance include particulate lumps, aggregates of a plurality of microparticles, and irregularly shaped lumps.
　上記芯物質の平均径（平均粒子径）は、好ましくは０．００１μｍ以上、より好ましくは０．０５μｍ以上、好ましくは０．９μｍ以下、より好ましくは０．２μｍ以下である。上記芯物質の平均径が上記下限以上及び上記上限以下であると、電極間の接続抵抗が効果的に低くなる。 The average diameter (average particle diameter) of the core material is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. When the average diameter of the core substance is not less than the above lower limit and not more than the above upper limit, the connection resistance between the electrodes is effectively reduced.
　上記芯物質の「平均径（平均粒子径）」は、数平均径（数平均粒子径）を示す。芯物質の平均径は、例えば、任意の芯物質５０個を電子顕微鏡又は光学顕微鏡にて観察し、平均値を算出することにより求めることができる。 The "average diameter (average particle diameter)" of the above-mentioned core substance indicates the number average diameter (number average particle diameter). The average diameter of the core substance can be determined, for example, by observing 50 arbitrary core substances with an electron microscope or an optical microscope and calculating the average value.
　（絶縁性物質）
　本発明に係る導電性粒子は、上記Ｎｉ－Ｓｎ導電層の外表面上に配置された絶縁性物質を備えることが好ましい。この場合には、導電性粒子を電極間の接続に用いると、隣接する電極間の短絡を防止できる。具体的には、複数の導電性粒子が接触したときに、複数の電極間に絶縁性物質が存在するので、上下の電極間ではなく横方向に隣り合う電極間の短絡を防止できる。なお、電極間の接続の際に、２つの電極で導電性粒子を加圧することにより、導電性粒子のＮｉ－Ｓｎ導電層と電極との間の絶縁性物質を容易に排除できる。導電性粒子がＮｉ－Ｓｎ導電層の外表面に複数の突起を有する場合には、導電性粒子のＮｉ－Ｓｎ導電層と電極との間の絶縁性物質を容易に排除できる。 (insulating material)
The conductive particles according to the present invention preferably include an insulating material disposed on the outer surface of the Ni--Sn conductive layer. In this case, if conductive particles are used to connect the electrodes, short circuits between adjacent electrodes can be prevented. Specifically, when a plurality of conductive particles come into contact with each other, since an insulating substance exists between the plurality of electrodes, a short circuit can be prevented not between upper and lower electrodes but between horizontally adjacent electrodes. Note that when connecting the electrodes, by pressurizing the conductive particles with two electrodes, the insulating material between the Ni—Sn conductive layer of the conductive particles and the electrodes can be easily removed. When the conductive particles have a plurality of protrusions on the outer surface of the Ni--Sn conductive layer, the insulating material between the Ni--Sn conductive layer of the conductive particles and the electrode can be easily removed.
　電極間の圧着時に上記絶縁性物質をより一層容易に排除できることから、上記絶縁性物質は、絶縁性粒子であることが好ましい。 The insulating substance is preferably insulating particles, since the insulating substance can be more easily removed during crimping between the electrodes.
　上記絶縁性物質の材料である絶縁性樹脂の具体例としては、ポリオレフィン類、（メタ）アクリレート重合体、（メタ）アクリレート共重合体、ブロックポリマー、熱可塑性樹脂、熱可塑性樹脂の架橋物、熱硬化性樹脂及び水溶性樹脂等が挙げられる。 Specific examples of the insulating resin that is the material for the above-mentioned insulating substance include polyolefins, (meth)acrylate polymers, (meth)acrylate copolymers, block polymers, thermoplastic resins, crosslinked thermoplastic resins, and thermoplastic resins. Examples include curable resins and water-soluble resins.
　上記ポリオレフィン類としては、ポリエチレン、エチレン－酢酸ビニル共重合体及びエチレン－アクリル酸エステル共重合体等が挙げられる。上記（メタ）アクリレート重合体としては、ポリメチル（メタ）アクリレート、ポリエチル（メタ）アクリレート及びポリブチル（メタ）アクリレート等が挙げられる。上記ブロックポリマーとしては、ポリスチレン、スチレン－アクリル酸エステル共重合体、ＳＢ型スチレン－ブタジエンブロック共重合体、及びＳＢＳ型スチレン－ブタジエンブロック共重合体、並びにこれらの水素添加物等が挙げられる。上記熱可塑性樹脂としては、ビニル重合体及びビニル共重合体等が挙げられる。上記熱硬化性樹脂としては、エポキシ樹脂、フェノール樹脂及びメラミン樹脂等が挙げられる。上記水溶性樹脂としては、ポリビニルアルコール、ポリアクリル酸、ポリアクリルアミド、ポリビニルピロリドン、ポリエチレンオキシド及びメチルセルロース等が挙げられる。上記絶縁性樹脂は、水溶性樹脂を含むことが好ましく、ポリビニルアルコールを含むことがより好ましい。 Examples of the polyolefins include polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, and the like. Examples of the (meth)acrylate polymer include polymethyl (meth)acrylate, polyethyl (meth)acrylate, and polybutyl (meth)acrylate. Examples of the block polymer include polystyrene, styrene-acrylic acid ester copolymer, SB type styrene-butadiene block copolymer, SBS type styrene-butadiene block copolymer, and hydrogenated products thereof. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. Examples of the thermosetting resin include epoxy resin, phenol resin, and melamine resin. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, and methylcellulose. The insulating resin preferably contains a water-soluble resin, and more preferably contains polyvinyl alcohol.
　上記Ｎｉ－Ｓｎ導電層の表面上に絶縁性物質を配置する方法としては、化学的方法、及び物理的もしくは機械的方法等が挙げられる。上記化学的方法としては、例えば、界面重合法、粒子存在下での懸濁重合法及び乳化重合法等が挙げられる。上記物理的もしくは機械的方法としては、スプレードライ、ハイブリダイゼーション、静電付着法、噴霧法、ディッピング及び真空蒸着による方法等が挙げられる。なかでも、絶縁性物質が脱離し難いことから、上記導電層の表面に、化学結合を介して上記絶縁性物質を配置する方法が好ましい。 Examples of methods for disposing an insulating substance on the surface of the Ni—Sn conductive layer include chemical methods, physical or mechanical methods, and the like. Examples of the chemical methods include interfacial polymerization, suspension polymerization in the presence of particles, and emulsion polymerization. Examples of the physical or mechanical methods include spray drying, hybridization, electrostatic adhesion, spraying, dipping, and vacuum deposition. Among these, a method in which the insulating substance is disposed on the surface of the conductive layer via a chemical bond is preferred because the insulating substance is difficult to detach.
　上記Ｎｉ－Ｓｎ導電層の外表面、及び絶縁性粒子の表面はそれぞれ、反応性官能基を有する化合物によって被覆されていてもよい。導電層の外表面と絶縁性粒子の表面とは、直接化学結合していなくてもよく、反応性官能基を有する化合物によって間接的に化学結合していてもよい。導電層の外表面にカルボキシル基を導入した後、該カルボキシル基がポリエチレンイミンなどの高分子電解質を介して絶縁性粒子の表面の官能基と化学結合していてもよい。 The outer surface of the Ni—Sn conductive layer and the surface of the insulating particles may each be coated with a compound having a reactive functional group. The outer surface of the conductive layer and the surface of the insulating particles may not be directly chemically bonded to each other, but may be indirectly chemically bonded to each other through a compound having a reactive functional group. After introducing a carboxyl group to the outer surface of the conductive layer, the carboxyl group may be chemically bonded to a functional group on the surface of the insulating particle via a polymer electrolyte such as polyethyleneimine.
　上記絶縁性物質の平均径（平均粒子径）は、導電性粒子の粒子径及び導電性粒子の用途等によって適宜選択できる。上記絶縁性物質の平均径（平均粒子径）は好ましくは０．００５μｍ以上、より好ましくは０．０１μｍ以上、好ましくは１μｍ以下、より好ましくは０．５μｍ以下である。絶縁性物質の平均径が上記下限以上であると、導電性粒子がバインダー樹脂中に分散されたときに、複数の導電性粒子における導電層同士が接触し難くなる。絶縁性粒子の平均径が上記上限以下であると、電極間の接続の際に、電極と導電性粒子との間の絶縁性物質を排除するために、圧力を高くしすぎる必要がなくなり、高温に加熱する必要もなくなる。 The average diameter (average particle diameter) of the above-mentioned insulating substance can be appropriately selected depending on the particle diameter of the conductive particles, the use of the conductive particles, etc. The average diameter (average particle diameter) of the insulating substance is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 1 μm or less, and more preferably 0.5 μm or less. When the average diameter of the insulating substance is equal to or larger than the above lower limit, when the conductive particles are dispersed in the binder resin, the conductive layers of the plurality of conductive particles are difficult to come into contact with each other. When the average diameter of the insulating particles is below the above upper limit, there is no need to apply too high a pressure to eliminate the insulating material between the electrodes and the conductive particles when connecting the electrodes, and high-temperature There is no need to heat it up.
　上記絶縁性物質の「平均径（平均粒子径）」は、数平均径（数平均粒子径）を示す。絶縁性物質の平均径は、粒度分布測定装置等を用いて求められる。 The "average diameter (average particle diameter)" of the above-mentioned insulating substance indicates the number average diameter (number average particle diameter). The average diameter of the insulating substance is determined using a particle size distribution measuring device or the like.
　（導電材料）
　本発明に係る導電材料は、上述した導電性粒子と、バインダー樹脂とを含む。上記導電性粒子は、バインダー樹脂中に分散されて用いられることが好ましく、バインダー樹脂中に分散されて導電材料として用いられることが好ましい。上記導電材料は、異方性導電材料であることが好ましい。上記導電材料は、電極間の電気的な接続に用いられることが好ましい。上記導電材料は、回路接続材料であることが好ましい。 (conductive material)
The electrically conductive material according to the present invention includes the above-mentioned electrically conductive particles and a binder resin. The conductive particles are preferably used as a conductive material by being dispersed in a binder resin, and preferably used as a conductive material by being dispersed in a binder resin. Preferably, the conductive material is an anisotropic conductive material. The conductive material is preferably used for electrical connection between electrodes. Preferably, the conductive material is a circuit connection material.
　上記バインダー樹脂は特に限定されない。上記バインダー樹脂として、公知の絶縁性の樹脂が用いられる。 The above binder resin is not particularly limited. As the binder resin, a known insulating resin is used.
　上記バインダー樹脂としては、例えば、ビニル樹脂、熱可塑性樹脂、硬化性樹脂、熱可塑性ブロック共重合体及びエラストマー等が挙げられる。上記バインダー樹脂は１種のみが用いられてもよく、２種以上が併用されてもよい。 Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. Only one type of the binder resin may be used, or two or more types may be used in combination.
　上記ビニル樹脂としては、例えば、酢酸ビニル樹脂、アクリル樹脂及びスチレン樹脂等が挙げられる。上記熱可塑性樹脂としては、例えば、ポリオレフィン樹脂、エチレン－酢酸ビニル共重合体及びポリアミド樹脂等が挙げられる。上記硬化性樹脂としては、例えば、エポキシ樹脂、ウレタン樹脂、ポリイミド樹脂及び不飽和ポリエステル樹脂等が挙げられる。なお、上記硬化性樹脂は、常温硬化型樹脂、熱硬化型樹脂、光硬化型樹脂又は湿気硬化型樹脂であってもよい。上記硬化性樹脂は、硬化剤と併用されてもよい。上記熱可塑性ブロック共重合体としては、例えば、スチレン－ブタジエン－スチレンブロック共重合体、スチレン－イソプレン－スチレンブロック共重合体、スチレン－ブタジエン－スチレンブロック共重合体の水素添加物、及びスチレン－イソプレン－スチレンブロック共重合体の水素添加物等が挙げられる。上記エラストマーとしては、例えば、スチレン－ブタジエン共重合ゴム、及びアクリロニトリル－スチレンブロック共重合ゴム等が挙げられる。 Examples of the vinyl resin include vinyl acetate resin, acrylic resin, and styrene resin. Examples of the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins. Examples of the curable resin include epoxy resin, urethane resin, polyimide resin, and unsaturated polyester resin. Note that the curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The above-mentioned curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymers include styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, hydrogenated products of styrene-butadiene-styrene block copolymers, and styrene-isoprene block copolymers. - Examples include hydrogenated products of styrene block copolymers. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.
　上記導電材料は、上記導電性粒子及び上記バインダー樹脂の他に、例えば、充填剤、増量剤、軟化剤、可塑剤、重合触媒、硬化触媒、着色剤、酸化防止剤、熱安定剤、光安定剤、紫外線吸収剤、滑剤、帯電防止剤及び難燃剤等の各種添加剤を含んでいてもよい。 In addition to the conductive particles and the binder resin, the conductive materials include, for example, fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, heat stabilizers, and light stabilizers. It may contain various additives such as a UV absorber, a lubricant, an antistatic agent, and a flame retardant.
　本発明に係る導電材料は、導電ペースト及び導電フィルム等として使用され得る。本発明に係る導電材料が、導電フィルムである場合には、導電性粒子を含む導電フィルムに、導電性粒子を含まないフィルムが積層されていてもよい。上記導電ペーストは、異方性導電ペーストであることが好ましい。上記導電フィルムは、異方性導電フィルムであることが好ましい。 The conductive material according to the present invention can be used as a conductive paste, a conductive film, and the like. When the conductive material according to the present invention is a conductive film, a film not containing conductive particles may be laminated on a conductive film containing conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.
　上記導電材料１００重量％中、上記バインダー樹脂の含有量は好ましくは１０重量％以上、より好ましくは３０重量％以上、さらに好ましくは５０重量％以上、特に好ましくは７０重量％以上、好ましくは９９．９９重量％以下、より好ましくは９９．９重量％以下である。上記バインダー樹脂の含有量が上記下限以上及び上記上限以下であると、電極間に導電性粒子が効率的に配置され、導電材料により接続された接続対象部材の接続信頼性がより一層高くなる。 The content of the binder resin in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, particularly preferably 70% by weight or more, and preferably 99% by weight or more. It is 99% by weight or less, more preferably 99.9% by weight or less. When the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target members connected by the conductive material becomes even higher.
　上記導電材料１００重量％中、上記導電性粒子の含有量は、好ましくは０．０１重量％以上、より好ましくは０．１重量％以上、好ましくは４０重量％以下、より好ましくは２０重量％以下、さらに好ましくは１０重量％以下である。上記導電性粒子の含有量が上記下限以上及び上記上限以下であると、電極間の導通信頼性がより一層高くなる。 The content of the conductive particles in 100% by weight of the conductive material is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 40% by weight or less, and more preferably 20% by weight or less. , more preferably 10% by weight or less. When the content of the conductive particles is at least the above lower limit and at most the above upper limit, the reliability of conduction between the electrodes becomes even higher.
　（接続構造体）
　上記導電性粒子を用いて、又は上記導電性粒子とバインダー樹脂とを含む導電材料を用いて、接続対象部材を接続することにより、接続構造体を得ることができる。 (connection structure)
A connected structure can be obtained by connecting members to be connected using the conductive particles or using a conductive material containing the conductive particles and a binder resin.
　上記接続構造体は、第１の接続対象部材と、第２の接続対象部材と、第１，第２の接続対象部材を接続している接続部とを備え、該接続部が上述した導電性粒子により形成されているか、又は上述した導電性粒子とバインダー樹脂とを含む導電材料により形成されている接続構造体であることが好ましい。上記接続構造体では、上記第１の電極と上記第２の電極とが上述した導電性粒子により電気的に接続されていることが好ましい。導電性粒子が用いられた場合には、接続部自体が導電性粒子である。すなわち、第１，第２の接続対象部材が導電性粒子により接続される。 The connection structure includes a first connection target member, a second connection target member, and a connection part connecting the first and second connection target members, and the connection part has the above-mentioned conductive property. It is preferable that the connected structure be formed of particles or a conductive material containing the above-mentioned conductive particles and a binder resin. In the connected structure, it is preferable that the first electrode and the second electrode are electrically connected by the conductive particles described above. If conductive particles are used, the connection itself is the conductive particle. That is, the first and second connection target members are connected by the conductive particles.
　図５に、本発明の第１の実施形態に係る導電性粒子を用いた接続構造体を模式的に断面図で示す。 FIG. 5 schematically shows a cross-sectional view of a connected structure using conductive particles according to the first embodiment of the present invention.
　図５に示す接続構造体５１は、第１の接続対象部材５２と、第２の接続対象部材５３と、第１，第２の接続対象部材５２，５３を接続している接続部５４とを備える。接続部５４は、導電性粒子１を含む導電材料を硬化させることにより形成されている。なお、図５では、導電性粒子１は、図示の便宜上、略図的に示されている。導電性粒子１にかえて、導電性粒子１１，２１等を用いてもよい。 The connection structure 51 shown in FIG. 5 connects a first connection target member 52, a second connection target member 53, and a connection part 54 connecting the first and second connection target members 52 and 53. Be prepared. The connecting portion 54 is formed by curing a conductive material containing the conductive particles 1. Note that in FIG. 5, the conductive particles 1 are shown schematically for convenience of illustration. In place of the conductive particles 1, conductive particles 11, 21, etc. may be used.
　第１の接続対象部材５２は表面（上面）に、複数の第１の電極５２ａを有する。第２の接続対象部材５３は表面（下面）に、複数の第２の電極５３ａを有する。第１の電極５２ａと第２の電極５３ａとが、１つ又は複数の導電性粒子１により電気的に接続されている。従って、第１，第２の接続対象部材５２，５３が導電性粒子１により電気的に接続されている。 The first connection target member 52 has a plurality of first electrodes 52a on its surface (upper surface). The second connection target member 53 has a plurality of second electrodes 53a on the front surface (lower surface). The first electrode 52a and the second electrode 53a are electrically connected by one or more conductive particles 1. Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1.
　上記接続構造体の製造方法は特に限定されない。接続構造体の製造方法の一例としては、第１の接続対象部材と第２の接続対象部材との間に上記導電材料を配置し、積層体を得た後、該積層体を加熱及び加圧する方法等が挙げられる。上記加圧の圧力は９．８×１０４Ｐａ～４．９×１０６Ｐａ程度である。上記加熱の温度は、１２０℃～２２０℃程度である。 The method for manufacturing the above-mentioned connected structure is not particularly limited. As an example of a method for manufacturing a connected structure, the conductive material is placed between a first member to be connected and a second member to be connected, a laminate is obtained, and then the laminate is heated and pressurized. Examples include methods. The pressure of the above pressurization is about 9.8×10 4 Pa to 4.9×10 6 Pa. The heating temperature is about 120°C to 220°C.
　上記接続対象部材としては、具体的には、半導体チップ、コンデンサ及びダイオード等の電子部品、並びにプリント基板、フレキシブルプリント基板、ガラスエポキシ基板及びガラス基板等の回路基板などの電子部品等が挙げられる。上記接続対象部材は電子部品であることが好ましい。上記導電性粒子は、電子部品における電極の電気的な接続に用いられることが好ましい。 Specifically, the above-mentioned connection target members include electronic components such as semiconductor chips, electronic components such as capacitors and diodes, and circuit boards such as printed circuit boards, flexible printed circuit boards, glass epoxy boards, and glass substrates. It is preferable that the member to be connected is an electronic component. The conductive particles are preferably used for electrical connection of electrodes in electronic components.
　上記接続対象部材に設けられている電極としては、金電極、ニッケル電極、錫電極、アルミニウム電極、銅電極、銀電極、モリブデン電極及びタングステン電極等の金属電極が挙げられる。上記接続対象部材がフレキシブルプリント基板である場合には、上記電極は金電極、ニッケル電極、錫電極又は銅電極であることが好ましい。上記接続対象部材がガラス基板である場合には、上記電極はアルミニウム電極、銅電極、モリブデン電極又はタングステン電極であることが好ましい。なお、上記電極がアルミニウム電極である場合には、アルミニウムのみで形成された電極であってもよく、金属酸化物層の表面にアルミニウム層が積層された電極であってもよい。上記金属酸化物層の材料としては、３価の金属元素がドープされた酸化インジウム及び３価の金属元素がドープされた酸化亜鉛等が挙げられる。上記３価の金属元素としては、Ｓｎ、Ａｌ及びＧａ等が挙げられる。 Examples of the electrodes provided on the connection target member include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, silver electrodes, molybdenum electrodes, and tungsten electrodes. When the member to be connected is a flexible printed circuit board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. In addition, when the said electrode is an aluminum electrode, it may be an electrode formed only with aluminum, and the electrode may be an electrode in which an aluminum layer is laminated|stacked on the surface of a metal oxide layer. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal elements include Sn, Al, and Ga.
　以下、実施例及び比較例を挙げて、本発明を具体的に説明する。本発明は、以下の実施例のみに限定されない。 Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples. The invention is not limited only to the following examples.
　導電性粒子を得るために、下記の基材粒子を用意した。 In order to obtain conductive particles, the following base particles were prepared.
　基材粒子Ａ：粒子径が３．０μｍであるジビニルベンゼン共重合体樹脂粒子（積水化学工業社製「ミクロパールＳＰ－２０３」）
　基材粒子Ｂ：基材粒子Ａと粒子径のみが異なり、粒子径が２．５μｍである基材粒子
　基材粒子Ｃ：基材粒子Ａと粒子径のみが異なり、粒子径が１０．０μｍである基材粒子
　基材粒子Ｄ：粒子径が３．０μｍであるコアシェル型の有機無機ハイブリッド粒子（下記の合成例１に従って作製）
　基材粒子Ｅ：粒子径が３．０μｍである有機無機ハイブリッド粒子（下記の合成例２に従って作製） Base particle A: divinylbenzene copolymer resin particles with a particle size of 3.0 μm (“Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.)
Base material particle B: Base material particle that differs from base material particle A only in particle size and has a particle size of 2.5 μm. Base material particle C: Only differs from base material particle A in particle size and has a particle size of 10.0 μm. A certain base material particle Base material particle D: Core-shell type organic-inorganic hybrid particle with a particle diameter of 3.0 μm (produced according to Synthesis Example 1 below)
Base particle E: organic-inorganic hybrid particle having a particle diameter of 3.0 μm (produced according to Synthesis Example 2 below)
　（合成例１）
　粒子径が２．５μｍであるジビニルベンゼン共重合体樹脂粒子（積水化学工業社製「ミクロパールＳＰ－２０２」）の表面を、ゾルゲル反応による縮合反応を用いてシリカシェル（厚み２５０ｎｍ）により被覆して、基材粒子Ｄを得た。 (Synthesis example 1)
The surface of divinylbenzene copolymer resin particles ("Micropearl SP-202" manufactured by Sekisui Chemical Co., Ltd.) having a particle size of 2.5 μm was coated with a silica shell (thickness 250 nm) using a condensation reaction based on a sol-gel reaction. Thus, base material particles D were obtained.
　（合成例２）
　撹拌機及び温度計が取り付けられた５００ｍＬの反応容器内に、０．１３重量％のアンモニア水溶液３００ｇを入れた。次に、反応容器内のアンモニア水溶液中に、メチルトリメトキシシラン４．１ｇと、ビニルトリメトキシシラン１９．２ｇと、シリコーンアルコキシオリゴマー（信越化学工業社製「Ｘ－４１－１０５３」）０．７ｇとの混合物をゆっくりと添加した。撹拌しながら、加水分解及び縮合反応を進行させた後、２５重量％アンモニア水溶液２．４ｍＬを添加し、アンモニア水溶液中から粒子を単離して、得られた粒子を酸素分圧１０－１７ａｔｍ、３５０℃で２時間焼成して、基材粒子Ｅを得た。 (Synthesis example 2)
300 g of a 0.13% by weight ammonia aqueous solution was placed in a 500 mL reaction vessel equipped with a stirrer and a thermometer. Next, 4.1 g of methyltrimethoxysilane, 19.2 g of vinyltrimethoxysilane, and 0.7 g of silicone alkoxy oligomer ("X-41-1053" manufactured by Shin-Etsu Chemical Co., Ltd.) were added to the ammonia aqueous solution in the reaction container. was added slowly. After allowing the hydrolysis and condensation reactions to proceed while stirring, 2.4 mL of a 25% by weight ammonia aqueous solution was added, the particles were isolated from the ammonia aqueous solution, and the obtained particles were heated to an oxygen partial pressure of 10 -17 atm, The base material particles E were obtained by baking at 350° C. for 2 hours.
　（実施例１）
　パラジウム触媒液を５重量％含むアルカリ溶液１００重量部に、上記基材粒子Ａ１０重量部を、超音波分散器を用いて分散させた後、溶液をろ過することにより、基材粒子Ａを取り出した。次いで、基材粒子Ａをジメチルアミンボラン１重量％溶液１００重量部に添加し、基材粒子Ａの表面を活性化させた。表面が活性化された基材粒子Ａを十分に水洗した後、蒸留水５００重量部に加え、分散させることにより、懸濁液（０）を得た。 (Example 1)
After dispersing 10 parts by weight of the above base material particles A in 100 parts by weight of an alkaline solution containing 5% by weight of palladium catalyst liquid using an ultrasonic disperser, the base material particles A were taken out by filtering the solution. . Next, the base particles A were added to 100 parts by weight of a 1% by weight dimethylamine borane solution to activate the surfaces of the base particles A. After thoroughly washing the surface-activated base material particles A with water, they were added to 500 parts by weight of distilled water and dispersed to obtain a suspension (0).
　また、硫酸ニッケル０．１４ｍｏｌ／Ｌと、ジメチルアミンボラン０．４６ｍｏｌ／Ｌと、クエン酸ナトリウム０．２ｍｏｌ／Ｌとを含むニッケルめっき液（１）（ｐＨ８．５）を用意した。上記懸濁液（０）を６０℃で撹拌しながら、上記ニッケルめっき液（１）を上記懸濁液（０）に徐々に滴下し、無電解ニッケル－ボロン合金めっきを行い、懸濁液（１）を得た。 In addition, a nickel plating solution (1) (pH 8.5) containing 0.14 mol/L of nickel sulfate, 0.46 mol/L of dimethylamine borane, and 0.2 mol/L of sodium citrate was prepared. While stirring the suspension (0) at 60°C, the nickel plating solution (1) was gradually dropped into the suspension (0) to perform electroless nickel-boron alloy plating. 1) was obtained.
　次に、硫酸ニッケル０．１４ｍｏｌ／Ｌと、ヒドラジン０．４５ｍｏｌ／Ｌとを含むニッケルめっき液（２）（ｐＨ８．０）を用意した。上記懸濁液（１）を６５℃で撹拌しながら、上記ニッケルめっき液（２）を上記懸濁液（１）に徐々に滴下し、無電解ニッケルめっきを行い、懸濁液（２）を得た。 Next, a nickel plating solution (2) (pH 8.0) containing 0.14 mol/L of nickel sulfate and 0.45 mol/L of hydrazine was prepared. While stirring the suspension (1) at 65°C, the nickel plating solution (2) was gradually dropped into the suspension (1) to perform electroless nickel plating, and the suspension (2) Obtained.
　硫酸ニッケル０．１４ｍｏｌ／Ｌと、スズ酸ナトリウム三水和物０．０９ｍｏｌ／Ｌと、グルコン酸ナトリウム０．４５ｍｏｌ／Ｌとを含むニッケルめっき液（３）（ｐＨ８．０）を用意した。上記懸濁液（２）を６５℃で撹拌しながら、上記ニッケルめっき液（３）を上記懸濁液（２）に徐々に滴下し、無電解ニッケル－錫合金めっきを行い、懸濁液（３）を得た。 A nickel plating solution (3) (pH 8.0) containing 0.14 mol/L of nickel sulfate, 0.09 mol/L of sodium stannate trihydrate, and 0.45 mol/L of sodium gluconate was prepared. While stirring the suspension (2) at 65°C, the nickel plating solution (3) was gradually dropped into the suspension (2) to perform electroless nickel-tin alloy plating, and the suspension ( 3) was obtained.
　その後、上記懸濁液（３）をろ過することにより、粒子を取り出し、水洗し、乾燥させることにより、基材粒子Ａの表面にＮｉ－Ｓｎ導電層（厚み１３６ｎｍ）が配置された導電性粒子を得た。 Thereafter, the particles are taken out by filtering the suspension (3), washed with water, and dried to form conductive particles with a Ni-Sn conductive layer (thickness 136 nm) arranged on the surface of the base particle A. I got it.
　（実施例２）
　硫酸ニッケル０．０７ｍｏｌ／Ｌと、スズ酸ナトリウム三水和物０．０４５ｍｏｌ／Ｌと、グルコン酸ナトリウム０．２２５ｍｏｌ／Ｌとを含むニッケルめっき液（ｐＨ８．０）を用意した。このニッケルめっき液をニッケルめっき液（３）の代わりに用いたこと以外は、実施例１と同様にして導電性粒子を得た。 (Example 2)
A nickel plating solution (pH 8.0) containing 0.07 mol/L of nickel sulfate, 0.045 mol/L of sodium stannate trihydrate, and 0.225 mol/L of sodium gluconate was prepared. Conductive particles were obtained in the same manner as in Example 1, except that this nickel plating solution was used instead of nickel plating solution (3).
　（実施例３）
　上記懸濁液（１）に、上記ニッケルめっき液（２）及び上記ニッケルめっき液（３）を同時に滴下したこと以外は、実施例１と同様にして導電性粒子を得た。 (Example 3)
Conductive particles were obtained in the same manner as in Example 1, except that the nickel plating solution (2) and the nickel plating solution (3) were simultaneously dropped into the suspension (1).
　（実施例４）
　上記懸濁液（０）に、上記ニッケルめっき液（１）、上記ニッケルめっき液（２）及び上記ニッケルめっき液（３）を同時に滴下したこと以外は、実施例１と同様にして導電性粒子を得た。 (Example 4)
Conductive particles were deposited in the same manner as in Example 1, except that the nickel plating solution (1), the nickel plating solution (2), and the nickel plating solution (3) were simultaneously dropped into the suspension (0). I got it.
　（実施例５）
　上記懸濁液（０）に、上記ニッケルめっき液（１）、上記ニッケルめっき液（２）のｐＨを８．５に変更したニッケルめっき液及び上記ニッケルめっき液（３）のｐＨを８．５に変更したニッケルめっき液を同時に滴下したこと以外は、実施例１と同様にして導電性粒子を得た。 (Example 5)
The pH of the nickel plating solution (1), the nickel plating solution (2) was changed to 8.5, and the pH of the nickel plating solution (3) was changed to 8.5 to the suspension (0). Conductive particles were obtained in the same manner as in Example 1, except that a changed nickel plating solution was dropped at the same time.
　（実施例６）
　上記ニッケルめっき液（１）、上記ニッケルめっき液（２）及び上記ニッケルめっき液（３）の滴下量を１．３倍としたこと以外は、実施例１と同様にして導電性粒子を得た。 (Example 6)
Conductive particles were obtained in the same manner as in Example 1, except that the dropping amounts of the nickel plating solution (1), the nickel plating solution (2), and the nickel plating solution (3) were increased by 1.3 times. .
　（実施例７）
　上記ニッケルめっき液（１）、上記ニッケルめっき液（２）及び上記ニッケルめっき液（３）の滴下量を０．８倍としたこと以外は、実施例１と同様にして導電性粒子を得た。 (Example 7)
Conductive particles were obtained in the same manner as in Example 1, except that the dropping amounts of the nickel plating solution (1), the nickel plating solution (2), and the nickel plating solution (3) were increased by 0.8 times. .
　（実施例８）
　上記ニッケルめっき液（３）のスズ酸ナトリウム三水和物の濃度を０．０９ｍоｌ／Ｌから０．１５ｍｏｌ／Ｌに変更し、かつグルコン酸ナトリウムの濃度を０．４５ｍоｌ／Ｌから０．７５ｍｏｌ／Ｌに変更したニッケルめっき液を用意した。このニッケルめっき液をニッケルめっき液（３）の代わりに用いたこと以外は、実施例１と同様にして導電性粒子を得た。 (Example 8)
The concentration of sodium stannate trihydrate in the nickel plating solution (3) was changed from 0.09 mol/L to 0.15 mol/L, and the concentration of sodium gluconate was changed from 0.45 mol/L to 0.75 mol/L. A nickel plating solution changed to L was prepared. Conductive particles were obtained in the same manner as in Example 1, except that this nickel plating solution was used instead of nickel plating solution (3).
　（実施例９）
　上記ニッケルめっき液（３）のスズ酸ナトリウム三水和物の濃度を０．０９ｍоｌ／Ｌから０．３０ｍｏｌ／Ｌに変更しかつグルコン酸ナトリウムの濃度を０．４５ｍоｌ／Ｌから０．９０ｍｏｌ／Ｌに変更したニッケルめっき液を用意した。このニッケルめっき液をニッケルめっき液（３）の代わりに用いたこと以外は、実施例１と同様にして導電性粒子を得た。 (Example 9)
The concentration of sodium stannate trihydrate in the nickel plating solution (3) was changed from 0.09 mol/L to 0.30 mol/L, and the concentration of sodium gluconate was changed from 0.45 mol/L to 0.90 mol/L. A nickel plating solution was prepared using a modified nickel plating solution. Conductive particles were obtained in the same manner as in Example 1, except that this nickel plating solution was used instead of nickel plating solution (3).
　（実施例１０）
　上記懸濁液（０）に、Ｎｉ粒子スラリー（平均粒子径１５０ｎｍ）２ｇを３分間かけて添加し、芯物質が付着された基材粒子を含む懸濁液を得た。得られた懸濁液を用いたこと以外は、実施例１と同様にして、導電性粒子を得た。得られた導電性粒子のＮｉ－Ｓｎ導電層の外表面には、突起が形成されていた。 (Example 10)
2 g of Ni particle slurry (average particle diameter: 150 nm) was added to the above suspension (0) over 3 minutes to obtain a suspension containing base particles to which the core material was attached. Conductive particles were obtained in the same manner as in Example 1, except that the obtained suspension was used. Protrusions were formed on the outer surface of the Ni--Sn conductive layer of the obtained conductive particles.
　（実施例１１）
　上記懸濁液（０）に、アルミナ粒子スラリー（平均粒子径１５０ｎｍ）０．５ｇを３分間かけて添加し、芯物質が付着された基材粒子を含む懸濁液を得た。得られた懸濁液を用いたこと以外は、実施例１と同様にして、導電性粒子を得た。得られた導電性粒子のＮｉ－Ｓｎ導電層の外表面には、突起が形成されていた。 (Example 11)
0.5 g of alumina particle slurry (average particle diameter: 150 nm) was added to the suspension (0) over 3 minutes to obtain a suspension containing base particles to which the core material was attached. Conductive particles were obtained in the same manner as in Example 1, except that the obtained suspension was used. Protrusions were formed on the outer surface of the Ni--Sn conductive layer of the obtained conductive particles.
　（実施例１２）
　上記懸濁液（０）に、Ｎｉ粒子スラリーを用いずに、導電部の形成時に部分的に析出量がかわるように調整して突起を形成して、Ｎｉ－Ｓｎ導電層の外表面に突起を形成したこと以外は、実施例１と同様にして、導電性粒子を得た。 (Example 12)
Protrusions were formed in the above suspension (0) without using Ni particle slurry by adjusting the amount of precipitation to be partially changed during formation of the conductive part, and protrusions were formed on the outer surface of the Ni-Sn conductive layer. Conductive particles were obtained in the same manner as in Example 1, except that .
　（実施例１３～１６）
　基材粒子を下記の表３に示すように変更したこと以外は、実施例１０と同様にして、導電性粒子を得た。得られた導電性粒子のＮｉ－Ｓｎ導電層の外表面には、突起が形成されていた。 (Examples 13 to 16)
Conductive particles were obtained in the same manner as in Example 10, except that the base particles were changed as shown in Table 3 below. Protrusions were formed on the outer surface of the Ni--Sn conductive layer of the obtained conductive particles.
　（実施例１７）
　（１）絶縁性粒子の作製
　４ツ口セパラブルカバー、撹拌翼、三方コック、冷却管及び温度プローブが取り付けられた１０００ｍＬのセパラブルフラスコを用意した。該セパラブルフラスコに、メタクリル酸メチル１００ｍｍｏｌと、Ｎ，Ｎ，Ｎ－トリメチル－Ｎ－２－メタクリロイルオキシエチルアンモニウムクロライド１ｍｍｏｌと、２，２’－アゾビス（２－アミジノプロパン）二塩酸塩１ｍｍｏｌとを含むモノマー組成物を、固形分率が５重量％となるようにイオン交換水に秤取した。その後、２００ｒｐｍで撹拌し、窒素雰囲気下７０℃で２４時間重合を行った。反応終了後、凍結乾燥させ、表面にアンモニウム基を有する絶縁性粒子（平均粒子径２２０ｎｍ、ＣＶ値１０％）を得た。得られた絶縁性粒子を超音波照射下でイオン交換水に分散させ、絶縁性粒子の１０重量％水分散液を得た。 (Example 17)
(1) Preparation of insulating particles A 1000 mL separable flask equipped with a four-necked separable cover, a stirring blade, a three-way cock, a cooling tube, and a temperature probe was prepared. Into the separable flask, 100 mmol of methyl methacrylate, 1 mmol of N,N,N-trimethyl-N-2-methacryloyloxyethylammonium chloride, and 1 mmol of 2,2'-azobis(2-amidinopropane) dihydrochloride were added. The monomer composition containing the monomer composition was weighed out into ion-exchanged water so that the solid content was 5% by weight. Thereafter, the mixture was stirred at 200 rpm and polymerized at 70° C. for 24 hours under a nitrogen atmosphere. After the reaction was completed, it was freeze-dried to obtain insulating particles (average particle diameter 220 nm, CV value 10%) having ammonium groups on the surface. The obtained insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10% by weight aqueous dispersion of insulating particles.
　（２）導電性粒子の作製
　実施例１０で得られた導電性粒子１０ｇをイオン交換水５００ｍＬに分散させ、上記分散液４ｇを添加し、室温で６時間撹拌した。３μｍのメッシュフィルターでろ過した後、更にメタノールで洗浄し、乾燥させ、導電性粒子を得た。得られた導電性粒子を走査型電子顕微鏡（ＳＥＭ）により観察したところ、Ｎｉ－Ｓｎ導電層の外表面が絶縁性粒子で被覆されていた。画像解析により、絶縁性粒子の被覆面積（絶縁性粒子の粒子径の投影面積）の、半径３．０μｍの球の表面積に対する割合（％）を算出したところ、被覆率は３０％であった。 (2) Preparation of conductive particles 10 g of conductive particles obtained in Example 10 were dispersed in 500 mL of ion-exchanged water, 4 g of the above dispersion was added, and the mixture was stirred at room temperature for 6 hours. After filtering through a 3 μm mesh filter, the particles were further washed with methanol and dried to obtain conductive particles. When the obtained conductive particles were observed using a scanning electron microscope (SEM), it was found that the outer surface of the Ni--Sn conductive layer was coated with insulating particles. By image analysis, the ratio (%) of the covered area of the insulating particles (the projected area of the particle diameter of the insulating particles) to the surface area of a sphere with a radius of 3.0 μm was calculated, and the coverage was 30%.
　（比較例１）
　ニッケルめっき液（３）を用いる無電解ニッケル－錫合金めっきの工程を除いてめっきを行ったこと以外は、実施例１と同様にして導電性粒子を得た。 (Comparative example 1)
Conductive particles were obtained in the same manner as in Example 1, except that plating was performed by omitting the step of electroless nickel-tin alloy plating using nickel plating solution (3).
　（比較例２）
　ニッケルめっき液（２）を用いる無電解ニッケルめっき及びニッケルめっき液（３）を用いる無電解ニッケル－錫合金めっきを先に行った後に、ニッケルめっき液（１）を用いて無電解ニッケル－ボロン合金めっきを行ったこと以外は、実施例１と同様にして導電性粒子を得た。 (Comparative example 2)
After electroless nickel plating using nickel plating solution (2) and electroless nickel-tin alloy plating using nickel plating solution (3), electroless nickel-boron alloy plating is performed using nickel plating solution (1). Conductive particles were obtained in the same manner as in Example 1 except that plating was performed.
　（比較例３）
　硫酸ニッケル０．１４ｍｏｌ／Ｌと、ヒドラジン１．４５ｍｏｌ／Ｌと、スズ酸ナトリウム三水和物０．９０ｍｏｌ／Ｌと、グルコン酸ナトリウム０．６０ｍｏｌ／Ｌとを含むニッケルめっき液（ｐＨ８．０）を用意した。ニッケルめっき液（１）、（２）、及び（３）の代わりに、このニッケルめっき液を用いて５８℃で無電解ニッケル－錫合金めっきを行ったこと以外は、実施例１と同様にして導電性粒子を得た。 (Comparative example 3)
Nickel plating solution (pH 8.0) containing 0.14 mol/L of nickel sulfate, 1.45 mol/L of hydrazine, 0.90 mol/L of sodium stannate trihydrate, and 0.60 mol/L of sodium gluconate. prepared. In the same manner as in Example 1, except that electroless nickel-tin alloy plating was performed at 58 ° C. using this nickel plating solution instead of nickel plating solutions (1), (2), and (3). Conductive particles were obtained.
　（比較例４）
　硫酸ニッケル０．１４ｍｏｌ／Ｌと、ヒドラジン１．０５ｍｏｌ／Ｌと、スズ酸ナトリウム三水和物０．３０ｍｏｌ／Ｌと、グルコン酸ナトリウム０．３０ｍｏｌ／Ｌとを含むニッケルめっき液（ｐＨ８．５）を用意した。ニッケルめっき液（１）、（２）、及び（３）の代わりに、このニッケルめっき液を用いて６５℃で無電解ニッケル－錫合金めっきを行ったこと以外は、実施例１と同様にして導電性粒子を得た。 (Comparative example 4)
Nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol/L, hydrazine 1.05 mol/L, sodium stannate trihydrate 0.30 mol/L, and sodium gluconate 0.30 mol/L prepared. In the same manner as in Example 1, except that electroless nickel-tin alloy plating was performed at 65 ° C. using this nickel plating solution instead of nickel plating solutions (1), (2), and (3). Conductive particles were obtained.
　（評価）
　（１）Ｎｉ－Ｓｎ導電層の領域Ｒ１及び領域Ｒ２におけるニッケル及び錫の分布
　集束イオンビームを用いて、得られた導電性粒子の薄膜切片を作製した。上記Ｎｉ－Ｓｎ導電層の全体の領域におけるニッケル及び錫の平均含有量を、ＩＣＰ－ＭＳ法により測定した。透過型電子顕微鏡ＦＥ－ＴＥＭ（日本電子社製「ＪＥＭ－２０１０ＦＥＦ」）を用いて、エネルギー分散型Ｘ線分析装置（ＥＤＳ）により、上記領域Ｒ１におけるニッケル及び錫の平均含有量、上記領域Ｒ２におけるニッケル及び錫の平均含有量、上記領域Ｒ１における錫の含有量の最大値、及び上記領域Ｒ２における錫の含有量の最大値を求めた。また、同様にして、Ｎｉ－Ｓｎ導電層の全体に含まれる錫の合計１００重量％中、領域Ｒ１における錫の含有量を求めた。さらに、上記領域Ｒ１及び上記領域Ｒ２における錫の含有量の最大値より、錫の含有量の最大値が存在する領域を調べ、Ｎｉ－Ｓｎ導電層の厚み１００％中、錫を含む領域の割合を求めた。 (evaluation)
(1) Distribution of nickel and tin in region R1 and region R2 of Ni—Sn conductive layer A thin film section of the obtained conductive particles was prepared using a focused ion beam. The average content of nickel and tin in the entire area of the Ni--Sn conductive layer was measured by ICP-MS method. Using a transmission electron microscope FE-TEM ("JEM-2010FEF" manufactured by JEOL Ltd.) and an energy dispersive X-ray spectrometer (EDS), the average content of nickel and tin in the above region R1 and the average content of nickel and tin in the above region R2 were determined. The average content of nickel and tin, the maximum value of the content of tin in the above region R1, and the maximum value of the content of tin in the above region R2 were determined. In addition, in the same manner, the content of tin in region R1 was determined out of the total 100% by weight of tin contained in the entire Ni--Sn conductive layer. Further, from the maximum value of the tin content in the above region R1 and the above region R2, the region where the maximum value of the tin content exists is investigated, and the proportion of the region containing tin in the 100% thickness of the Ni-Sn conductive layer is determined. I asked for
　（２）初期の接続抵抗（Ａ）
　得られた導電性粒子を含有量が１０重量％となるように、三井化学社製「ストラクトボンドＸＮ－５Ａ」に添加し、分散させて、異方性導電ペーストを作製した。 (2) Initial connection resistance (A)
The obtained conductive particles were added to "Structbond XN-5A" manufactured by Mitsui Chemicals, Inc. so that the content was 10% by weight, and dispersed to prepare an anisotropic conductive paste.
　Ｌ／Ｓが２０μｍ／２０μｍであるＩＴＯ電極パターンを上面に有する透明ガラス基板を用意した。また、Ｌ／Ｓが２０μｍ／２０μｍである金電極パターンを下面に有する半導体チップを用意した。 A transparent glass substrate having an ITO electrode pattern with L/S of 20 μm/20 μm on the top surface was prepared. Further, a semiconductor chip having a gold electrode pattern with L/S of 20 μm/20 μm on the lower surface was prepared.
　上記透明ガラス基板上に、作製直後の異方性導電ペーストを厚さ３０μｍとなるように塗工し、異方性導電ペースト層を形成した。次に、異方性導電ペースト層上に上記半導体チップを、電極同士が対向するように積層した。その後、異方性導電ペースト層の温度が１８５℃となるようにヘッドの温度を調整しながら、半導体チップの上面に加圧加熱ヘッドを載せ、１ＭＰａの圧力をかけて異方性導電ペースト層を１８５℃で硬化させて、接続構造体を得た。 Immediately after preparation, the anisotropic conductive paste was applied to a thickness of 30 μm on the transparent glass substrate to form an anisotropic conductive paste layer. Next, the semiconductor chips were stacked on the anisotropic conductive paste layer so that the electrodes faced each other. After that, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185°C, a pressure heating head is placed on the top surface of the semiconductor chip, and a pressure of 1 MPa is applied to the anisotropic conductive paste layer. It was cured at 185°C to obtain a connected structure.
　得られた接続構造体の上下の電極間の接続抵抗を、４端子法により測定した。２つの接続抵抗の平均値を算出した。なお、電圧＝電流×抵抗の関係から、一定の電流を流した時の電圧を測定することにより接続抵抗を求めることができる。初期の接続抵抗（Ａ）を下記の基準で判定した。 The connection resistance between the upper and lower electrodes of the obtained connected structure was measured by a four-terminal method. The average value of the two connection resistances was calculated. Note that from the relationship of voltage=current×resistance, the connection resistance can be determined by measuring the voltage when a constant current is passed. The initial connection resistance (A) was determined based on the following criteria.
　［初期の接続抵抗（Ａ）の判定基準］
　○○○：接続抵抗が２．０Ω以下
　○○：接続抵抗が２．０Ωを超え、３．０Ω以下
　○：接続抵抗が３．０Ωを超え、５．０Ω以下
　△：接続抵抗が５．０Ωを超え、１０Ω以下
　×：接続抵抗が１０Ωを超える [Judgment criteria for initial connection resistance (A)]
○○○: Connection resistance is 2.0Ω or less ○○: Connection resistance is over 2.0Ω and 3.0Ω or less ○: Connection resistance is over 3.0Ω and 5.0Ω or less △: Connection resistance is 5.0Ω exceeds 10Ω or less ×: Connection resistance exceeds 10Ω
　（３）酸の存在下に晒された後の接続抵抗（Ｂ）
　得られた導電性粒子を８％の硫酸水溶液に室温（２３℃）で４５分間浸した。その後、ろ過することにより、粒子を取り出し、水洗し、エタノール置換して１０分間放置して粒子を乾燥させることで、酸に晒された導電性粒子を得た。得られた導電性粒子を用いて上記（２）と同様にして接続構造体を作製し、上記初期の接続抵抗（Ａ）と同様にして接続抵抗を測定した。酸の存在下に晒された後の接続抵抗（Ｂ）を下記の基準で判定した。 (3) Connection resistance (B) after being exposed to the presence of acid
The obtained conductive particles were immersed in an 8% sulfuric acid aqueous solution at room temperature (23° C.) for 45 minutes. Thereafter, the particles were taken out by filtration, washed with water, replaced with ethanol, and allowed to stand for 10 minutes to dry the particles, thereby obtaining conductive particles exposed to acid. A connected structure was produced using the obtained conductive particles in the same manner as in (2) above, and the connection resistance was measured in the same manner as the initial connection resistance (A). The connection resistance (B) after being exposed to the presence of acid was determined based on the following criteria.
　［酸の存在下に晒された後の接続抵抗（Ｂ）の判定基準］
　○○○：接続抵抗Ｂが、接続抵抗Ａの１．０倍以上１．５倍未満、かつ、１０Ω以下
　○○：接続抵抗Ｂが、接続抵抗Ａの１．５倍以上２．０倍未満、かつ、１０Ω以下
　○：接続抵抗Ｂが、接続抵抗Ａの２．０倍以上５．０倍未満、かつ、１０Ω以下
　△：接続抵抗Ｂが、接続抵抗Ａの５．０倍以上１０倍未満、かつ、１０Ω以下
　×：接続抵抗Ｂが、接続抵抗Ａの１０倍以上、又は、１０Ωを超える [Judgment criteria for connection resistance (B) after being exposed to the presence of acid]
○○○: Connection resistance B is 1.0 times or more and less than 1.5 times the connection resistance A, and 10Ω or less ○○: Connection resistance B is 1.5 times or more and less than 2.0 times the connection resistance A , and 10Ω or less ○: Connection resistance B is 2.0 times or more and less than 5.0 times the connection resistance A, and 10Ω or less △: Connection resistance B is 5.0 times or more and less than 10 times the connection resistance A , and 10Ω or less ×: Connection resistance B is 10 times or more than connection resistance A, or exceeds 10Ω
　（４）Ｎｉ－Ｓｎ導電層における電荷の移動
　上記（２）で得られた接続構造体の、互いに絶縁された測定端子間に、８５℃かつ８５％ＲＨの条件で１５Ｖの電圧を５００時間印加した。次いで、マイクロスコープ（キーエンス社製「ＶＨＸ６０００」）で導電性粒子を観察し、Ｎｉ－Ｓｎ導電層において金属腐食を防ぎ、電荷の移動を防ぐことができているか否かを、下記の基準で判定した。 (4) Charge movement in the Ni-Sn conductive layer A voltage of 15 V was applied for 500 hours at 85°C and 85% RH between the mutually insulated measurement terminals of the connected structure obtained in (2) above. did. Next, the conductive particles were observed with a microscope (Keyence Corporation "VHX6000"), and it was judged based on the following criteria whether metal corrosion and charge movement could be prevented in the Ni-Sn conductive layer. did.
　［Ｎｉ－Ｓｎ導電層における電荷の移動の判定基準］
　○：導電層が黒色化しておらず、かつ、消失していない
　×：導電層の表面の一部又は導電層全体が、黒色化又は消失している [Criteria for determining charge movement in the Ni-Sn conductive layer]
○: The conductive layer has not turned black and has not disappeared. ×: A part of the surface of the conductive layer or the entire conductive layer has turned black or disappeared.
　結果を下記の表１～４に示す。 The results are shown in Tables 1 to 4 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　１，１１，２１…導電性粒子
　２…基材粒子
　３，１２，２２Ａ…Ｎｉ－Ｓｎ導電層
　１１ａ…突起
　１２ａ…突起
　１３…芯物質
　１４…絶縁性物質
　２１ａ，２２ａ，２２Ａａ，２２Ｂａ…突起
　２２Ｂ…第２の導電層
　５１…接続構造体
　５２…第１の接続対象部材
　５２ａ…第１の電極
　５３…第２の接続対象部材
　５３ａ…第２の電極
　５４…接続部 DESCRIPTION OF SYMBOLS 1, 11, 21...Electroconductive particle 2... Base material particle 3,12,22A...Ni-Sn conductive layer 11a...Protrusion 12a...Protrusion 13...Core substance 14...Insulating substance 21a, 22a, 22Aa, 22Ba...Protrusion 22B ...Second conductive layer 51...Connection structure 52...First connection target member 52a...First electrode 53...Second connection target member 53a...Second electrode 54...Connection part

Claims (12)

  1. 　基材粒子と、
    　ニッケルと錫とを含むＮｉ－Ｓｎ導電層とを備え、
    　前記基材粒子の表面上に、前記Ｎｉ－Ｓｎ導電層が配置されており、
    　前記Ｎｉ－Ｓｎ導電層の全体の領域における錫の平均含有量が５重量％未満であり、
    　ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、５重量％以上である、導電性粒子。     base material particles;
    A Ni--Sn conductive layer containing nickel and tin,
    The Ni—Sn conductive layer is disposed on the surface of the base particle,
    the average content of tin in the entire area of the Ni-Sn conductive layer is less than 5% by weight,
    When the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the maximum value of the tin content in the outer half-thickness region of the Ni-Sn conductive layer is: 5% by weight or more of electrically conductive particles.
  2. 　ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、前記Ｎｉ－Ｓｎ導電層の全体に含まれる錫の合計１００重量％中の８０重量％以上の錫が含まれる、請求項１に記載の導電性粒子。 When the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, it is found that the tin content in the entire Ni-Sn conductive layer in the outer half-thickness region of the Ni-Sn conductive layer. The conductive particles according to claim 1, wherein the conductive particles contain 80% by weight or more of tin out of the total 100% by weight of tin contained.
  3. 　ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の厚み１５％以上の領域において、錫が含まれる、請求項１又は２に記載の導電性粒子。 According to claim 1 or 2, when the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, tin is contained in a region having a thickness of 15% or more of the Ni-Sn conductive layer. Conductive particles as described.
  4. 　ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の厚み１０％以上かつ５０％未満の領域において、５重量％以上の含有量で錫が含まれる、請求項１～３のいずれか１項に記載の導電性粒子。 When the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the content is 5% by weight or more in a region where the thickness of the Ni-Sn conductive layer is 10% or more and less than 50%. The conductive particles according to any one of claims 1 to 3, wherein the conductive particles contain tin.
  5. 　ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、
    　前記Ｎｉ－Ｓｎ導電層の厚み１０％以上かつ５０％未満の領域において、５重量％以上の含有量で錫が含まれ、かつ、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、５重量％以上４０重量％以下である、請求項１～３のいずれか１項に記載の導電性粒子。     When the tin content in the thickness direction of the Ni-Sn conductive layer was measured by TEM-EDX,
    In the area where the thickness of the Ni-Sn conductive layer is 10% or more and less than 50%, tin is contained in a content of 5% by weight or more, and in the outer 1/2 thickness area of the Ni-Sn conductive layer. The conductive particles according to any one of claims 1 to 3, wherein the maximum content of tin is 5% by weight or more and 40% by weight or less.
  6. 　ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の厚み３０％以下の領域において、５重量％以上の含有量で錫が含まれる、請求項１～３のいずれか１項に記載の導電性粒子。 When the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, it is found that tin is contained at a content of 5% by weight or more in a region where the thickness of the Ni-Sn conductive layer is 30% or less. The conductive particles according to any one of claims 1 to 3.
  7. 　ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、１０重量％以上である、請求項１～３のいずれか１項に記載の導電性粒子。 When the tin content in the thickness direction of the Ni-Sn conductive layer is measured by TEM-EDX, the maximum value of the tin content in the outer half-thickness region of the Ni-Sn conductive layer is: The conductive particles according to any one of claims 1 to 3, which are 10% by weight or more.
  8. 　ＴＥＭ－ＥＤＸにより前記Ｎｉ－Ｓｎ導電層の厚み方向における錫の含有量を測定したときに、
    　前記Ｎｉ－Ｓｎ導電層の厚み３０％以下の領域において、５重量％以上の含有量で錫が含まれ、かつ、前記Ｎｉ－Ｓｎ導電層の外側の厚み１／２の領域において、錫の含有量の最大値が、１０重量％以上である、請求項１～３のいずれか１項に記載の導電性粒子。     When the tin content in the thickness direction of the Ni-Sn conductive layer was measured by TEM-EDX,
    In a region of 30% or less in thickness of the Ni--Sn conductive layer, tin is contained in a content of 5% by weight or more, and in a region of 1/2 of the thickness outside the Ni--Sn conductive layer, tin is contained. The conductive particles according to any one of claims 1 to 3, wherein the maximum amount is 10% by weight or more.
  9. 　前記導電性粒子の粒子径が、０．１μｍ以上１０００μｍ以下である、請求項１～８のいずれか１項に記載の導電性粒子。 The conductive particles according to any one of claims 1 to 8, wherein the conductive particles have a particle diameter of 0.1 μm or more and 1000 μm or less.
  10. 　前記Ｎｉ－Ｓｎ導電層の外表面に複数の突起を有する、請求項１～９のいずれか１項に記載の導電性粒子。 The conductive particle according to any one of claims 1 to 9, having a plurality of protrusions on the outer surface of the Ni-Sn conductive layer.
  11. 　請求項１～１０のいずれか１項に記載の導電性粒子と、バインダー樹脂とを含む、導電材料。 A conductive material comprising the conductive particles according to any one of claims 1 to 10 and a binder resin.
  12. 　第１の電極を表面に有する第１の接続対象部材と、
    　第２の電極を表面に有する第２の接続対象部材と、
    　前記第１の接続対象部材と前記第２の接続対象部材とを接続している接続部とを備え、
    　前記接続部が、請求項１～１０のいずれか１項に記載の導電性粒子により形成されているか、又は前記導電性粒子とバインダー樹脂とを含む導電材料により形成されており、
    　前記第１の電極と前記第２の電極とが前記導電性粒子により電気的に接続されている、接続構造体。     a first connection target member having a first electrode on its surface;
    a second connection target member having a second electrode on its surface;
    comprising a connection part connecting the first connection target member and the second connection target member,
    The connecting portion is formed of the conductive particles according to any one of claims 1 to 10, or is formed of a conductive material containing the conductive particles and a binder resin,
    A connected structure in which the first electrode and the second electrode are electrically connected by the conductive particles.
PCT/JP2023/027151 2022-08-08 2023-07-25 Electroconductive particles, electroconductive material, and connection structure WO2024034386A1 (en)

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JP2015130328A (en) * 2013-12-03 2015-07-16 積水化学工業株式会社 Conductive particle, conductive material and connection structure body
WO2017138521A1 (en) * 2016-02-08 2017-08-17 積水化学工業株式会社 Conductive particles, conductive material and connected structure

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* Cited by examiner, † Cited by third party
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JP2015130328A (en) * 2013-12-03 2015-07-16 積水化学工業株式会社 Conductive particle, conductive material and connection structure body
WO2017138521A1 (en) * 2016-02-08 2017-08-17 積水化学工業株式会社 Conductive particles, conductive material and connected structure

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