WO2019058727A1 - Conductive composition and wiring board using same - Google Patents

Conductive composition and wiring board using same Download PDF

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Publication number
WO2019058727A1
WO2019058727A1 PCT/JP2018/026814 JP2018026814W WO2019058727A1 WO 2019058727 A1 WO2019058727 A1 WO 2019058727A1 JP 2018026814 W JP2018026814 W JP 2018026814W WO 2019058727 A1 WO2019058727 A1 WO 2019058727A1
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WO
WIPO (PCT)
Prior art keywords
conductive composition
conductor
mass
curing agent
resin
Prior art date
Application number
PCT/JP2018/026814
Other languages
French (fr)
Japanese (ja)
Inventor
梨江 勝又
牧 山田
将太 佐藤
征人 青山
広祐 田代
Original Assignee
矢崎総業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2018114377A external-priority patent/JP7156831B2/en
Application filed by 矢崎総業株式会社 filed Critical 矢崎総業株式会社
Priority to DE112018005323.7T priority Critical patent/DE112018005323T5/en
Priority to CN201880055001.2A priority patent/CN111065684A/en
Publication of WO2019058727A1 publication Critical patent/WO2019058727A1/en
Priority to US16/800,613 priority patent/US11479686B2/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/08—Metals
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/16—Nitrogen-containing compounds
    • C08K5/34—Heterocyclic compounds having nitrogen in the ring
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
    • C08L1/02—Cellulose; Modified cellulose
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
    • C08L63/04—Epoxynovolacs
    • 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
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/09—Use of materials for the conductive, e.g. metallic pattern

Definitions

  • the present invention relates to a conductive composition and a wiring board using the same. Specifically, the present invention provides a conductive composition capable of obtaining a conductor having a resistivity equivalent to that of silver bulk and good adhesion to a substrate, and a wiring board using the conductive composition. About.
  • an electric circuit is used as a base on which a thin and soft base film with electrical insulation and a conductive metal such as copper foil are bonded.
  • a flexible printed wiring board (FPC) is known.
  • the circuit of the FPC is usually manufactured by a method called a subtraction method.
  • a circuit can be formed by bonding a metal foil such as copper to a polyimide film and etching the metal foil.
  • Such a subtraction method requires complicated and very long steps such as photolithography, etching, chemical vapor deposition and the like, and has a problem that the throughput is very low.
  • processes such as photolithography and etching there are always problems regarding the environment such as waste liquid.
  • an additive method is being studied in which a conductor pattern is formed on an insulating plate, which is the reverse of the subtract method.
  • This method plating, printing by using a conductive composition, etc., deposition of metal on the necessary part of the substrate, and electric wire coated with polyimide on the substrate.
  • plating plating, printing by using a conductive composition, etc., deposition of metal on the necessary part of the substrate, and electric wire coated with polyimide on the substrate.
  • the printing method mainly uses a film as a base material, and further uses a conductive ink or a conductive composition as a conducting wire material, and combines an insulating film, a resist and the like there to form an electric circuit.
  • a conductive ink or conductive composition is composed of a metal component, an organic solvent, a reducing agent, an adhesive and the like, and a conductor is formed by baking after application to enable conduction.
  • Patent Document 1 discloses a conductive composition containing a thermoplastic resin and a thermosetting resin as a binder resin, a curing agent, and metal particles.
  • mixing solid content which consists of silver particles, and a solvent is disclosed.
  • Patent Document 2 contains a predetermined amount of silver particles having a particle diameter of 100 to 200 nm, and the average particle diameter of the whole silver particles is 60 to 800 nm, and further, a high number average molecular weight is a predetermined range as an additive.
  • a metal paste comprising molecular weight ethylcellulose is disclosed.
  • Patent Document 3 a silver compound and a predetermined amine mixed solution are mixed to form a complex compound containing the silver compound and the above amine, and the complex compound is heated and thermally decomposed to form silver nanoparticles. It is disclosed that. And in patent documents 3, the silver paint constituent containing the above-mentioned silver nanoparticle and an organic solvent is indicated.
  • Patent Document 4 discloses a curable conductive paste containing an epoxy resin, a curing agent, a conductive powder and a solvent.
  • Patent Document 5 discloses a thermosetting conductive paste containing (A) a conductive filler, (B) a thermosetting binder, (C) a cellulose resin, and (D) optionally an acrylonitrile-butadiene copolymer. It is done.
  • JP 2013-134914 A International Publication No. 2017/033911 JP, 2013-142173, A JP 2000-239636 A JP 2012-84440 A
  • An object of the present invention is a conductive composition capable of obtaining a conductor having a specific resistance equivalent to that of silver bulk and good adhesion to a substrate, and a wiring board using the conductive composition. It is to provide.
  • the conductive composition according to the first aspect of the present invention comprises metal nanoparticles having an average particle size of 30 nm to 600 nm, metal particles having an average particle size larger than the metal nanoparticles, and an oxirane ring in the molecule.
  • a conductive composition comprising a thermosetting resin, a curing agent, and a cellulose resin, wherein the specific resistance of a conductor formed by applying and baking the conductive composition to a substrate is 5.0 ⁇
  • the tape having an adhesion of 3.9 N / 10 mm to 39 N / 10 mm or less and 10 -6 ⁇ ⁇ cm or less is pressure-bonded to the conductor and peeled off, the conductor does not peel off from the substrate.
  • thermosetting resin is a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolac epoxy resin, glycidyl amine And at least one selected from the group consisting of epoxy resins and aliphatic epoxy resins.
  • the conductive composition according to the third aspect of the present invention relates to the conductive composition of the first or second aspect, wherein the curing agent is a five-membered heterocyclic aromatic compound containing nitrogen.
  • the conductive composition according to the fourth aspect of the present invention relates to the conductive composition according to any one of the first to third aspects, wherein the ratio of the content of the thermosetting resin to the content of the curing agent is 1 in mass ratio : 1 to 4: 1.
  • the conductive composition according to the fifth aspect of the present invention relates to the conductive composition according to any one of the first to fourth aspects, wherein the content of the cellulose resin is 0.1 mass with respect to the entire conductive composition. % To 4% by mass.
  • the conductive composition according to the sixth aspect of the present invention relates to the conductive composition according to any one of the first to fifth aspects, wherein a total of a thermosetting resin and a curing agent relative to the entire conductive composition.
  • the content is 0.1% by mass to 6% by mass.
  • the conductive composition according to a seventh aspect of the present invention relates to the conductive composition according to any one of the first to sixth aspects, wherein the total of the thermosetting composition and the curing agent relative to the entire conductive composition.
  • the content is 0.1% by mass to 5% by mass.
  • the conductive composition according to the eighth aspect of the present invention relates to the conductive composition according to any one of the first to seventh aspects, wherein the total of the thermosetting resin and the curing agent relative to the entire conductive composition.
  • the content is 0.1% by mass to 2% by mass.
  • the conductive composition according to a ninth aspect of the present invention relates to the conductive composition according to any one of the first to eighth aspects, wherein the metal particles have an average particle size of 1 ⁇ m to 5 ⁇ m.
  • a wiring board according to a tenth aspect of the present invention includes a conductor obtained from the conductive composition according to any one of the first to ninth aspects.
  • the conductive composition of the present embodiment contains metal nanoparticles, metal particles, a thermosetting resin, a curing agent, and a cellulose resin. Each component will be described in detail below.
  • the conductive composition of the present embodiment contains metal nanoparticles having an average particle size of 30 nm to 600 nm.
  • the conductive composition of the present embodiment contains metal nanoparticles having an average particle size of 30 nm to 600 nm.
  • the diameter of the metal particles decreases, the number of metal atoms present on the surface of the particles increases, so the melting point of the metal decreases. Therefore, by using such metal nanoparticles for the conductive composition, it becomes possible to form a conductor at a relatively low temperature.
  • the average particle diameter of the metal nanoparticles is 30 nm to 600 nm, the gaps between the metal particles can be filled with the metal nanoparticles. Therefore, since the metal nanoparticles and the metal particles are sintered to form a dense sintered body, it is possible to enhance the conductivity of the conductor obtained by firing the conductive composition.
  • the average particle diameter of the metal nanoparticles is more preferably 70 nm to 600 nm from the viewpoint of forming a denser sintered body and enhancing the conductivity. Moreover, in the present specification, the average particle size of metal nanoparticles refers to the median diameter (50% diameter, D50) measured by the dynamic light scattering method.
  • the metal constituting the metal nanoparticles is not particularly limited, but may be gold, silver, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc and titanium It is preferable to contain at least one selected from the group consisting of Also, the metal constituting the metal nanoparticles is a group consisting of gold, silver, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc and titanium It is more preferable to consist of at least one selected.
  • the metal constituting the metal nanoparticles preferably contains at least one selected from the group consisting of gold, silver, copper and platinum. Fine wiring can be formed by using such metal nanoparticles. Furthermore, the resistance value of the conductor after firing can be reduced, and the surface smoothness of the conductor can be enhanced. Among these metals, it is preferable to use silver from the viewpoint of being able to be easily reduced by firing of the conductive composition to form a dense sintered body and to reduce the specific resistance of the obtained conductor.
  • the conductive composition according to the present embodiment contains metal particles having an average particle size larger than the metal nanoparticles, in addition to the above-described metal nanoparticles. By using such metal particles, the conductor after firing can be densified to reduce the specific resistance.
  • the average particle size of the metal particles is preferably 1 ⁇ m to 5 ⁇ m.
  • the conductivity of the conductor can be enhanced. Further, as described later, even when the conductive composition is applied to the insulating base material by the screen printing method, there is little possibility that the metal particles are clogged with the screen printing mesh, so that a fine circuit is efficiently formed. It becomes possible.
  • the average particle size of the metal particles refers to the median diameter (50% diameter, D50) measured by the dynamic light scattering method.
  • the metal constituting the metal particle is, like the metal nanoparticle, gold, silver, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc and titanium It is preferable to contain at least one selected from the group consisting of The metal constituting the metal particles is selected from the group consisting of gold, silver, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc and titanium It is more preferable that it consists of at least 1 type.
  • the metal constituting the metal particles preferably contains at least one selected from the group consisting of gold, silver, copper and platinum.
  • the metal particle which consists of these metals the resistance value of the conductor after baking can be reduced, and it becomes possible to also improve the surface smoothness of a conductor.
  • silver it is preferable to use silver from the viewpoint of being able to be easily reduced by firing of the conductive composition to form a dense sintered body and to reduce the specific resistance of the obtained conductor.
  • the ratio of the metal nanoparticles to the metal particles is not particularly limited, but, for example, the weight ratio is preferably 1: 9 to 9: 1.
  • the ratio of the metal nanoparticles to the metal particles is in this range, it is possible to obtain a conductor made of a dense sintered body and having improved conductivity.
  • the ratio of metal nanoparticles is lower than this range, it may be difficult to satisfy the specific resistance of the obtained conductor.
  • the proportion of metal nanoparticles is higher than this range, the viscosity of the conductive composition may decrease, making it difficult to achieve processability.
  • the conductive composition according to the present embodiment contains a thermosetting resin having an oxirane ring in the molecule.
  • Oxyrane also called ethylene oxide, is a three-membered cyclic ether.
  • thermosetting resin having an oxirane ring in the molecule is not particularly limited, but from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, glycidyl amine epoxy resin, and aliphatic epoxy resin Preferably, it is at least one selected.
  • the curing agent is not particularly limited as long as it can cure the thermosetting resin contained in the conductive composition, and, for example, an imidazole-based curing agent, an amide-based curing agent, a phenol-based curing agent, an amine-based curing agent, an acid An anhydride curing agent or the like can be used.
  • an imidazole-based curing agent an amide-based curing agent, a phenol-based curing agent, an amine-based curing agent, an acid An anhydride curing agent or the like
  • the curing agent one of these may be used alone, or two or more may be used in combination.
  • imidazole-based curing agent examples include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-isopropylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate and the like.
  • amide curing agent examples include dicyandiamide and the like.
  • a phenol-type curing agent As a phenol-type curing agent, a phenol resin etc. are mentioned, for example.
  • amine-based curing agents examples include aliphatic amines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and N-aminoethylpiperazine, and toluenediamine, xylenediamine, diaminodiphenylmethane, phenylenediamine and diaminodiphenylsulfone. Aromatic amines and the like can be mentioned.
  • Examples of the acid anhydride curing agent include phthalic anhydride, trimellitic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, hexahydrophthalic anhydride, nadic anhydride and the like. .
  • the curing agent is preferably a five-membered heterocyclic aromatic compound containing nitrogen.
  • the nitrogen-containing five-membered heterocyclic aromatic compound is a heterocyclic compound containing carbon and nitrogen, having a five-membered ring, and having aromaticity. Since such a curing agent generally has a curing start temperature of 100 ° C. or higher, curing is difficult to start at ordinary temperature even if the conductive composition is prepared and applied to a base material, etc. It is easy to start curing. Therefore, the handling of the conductive composition becomes easy, for example, at the time of manufacturing a wiring board or the like.
  • Examples of the curing agent of the nitrogen-containing five-membered heterocyclic aromatic compound include the above-mentioned imidazole curing agents.
  • the ratio of the content of the thermosetting resin to the curing agent is preferably 1: 1 to 4: 1 in mass ratio.
  • the ratio by weight of the thermosetting resin to the curing agent is more preferably 1: 1 to 3: 1.
  • the conductive composition of the present embodiment contains a cellulose resin.
  • a cellulose resin By uniformly dispersing the cellulose resin in the conductive composition, the flowability of the conductive composition can be increased, and the printability of the conductive composition can be prevented from being lowered. Also, by uniformly dispersing the cellulose resin in the conductive composition, the thermosetting resin and the curing agent become entangled with each other, thereby improving the adhesion between the conductor formed by firing the conductive composition and the substrate. be able to.
  • the cellulose ether includes cellulose single ether in which one kind of ether group is bonded to cellulose and cellulose mixed ether in which two or more kinds of ether groups are bonded.
  • Specific examples of the cellulose single ether include methyl cellulose, ethyl cellulose, propyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and the like.
  • the cellulose mixed ether examples include methyl ethyl cellulose, methyl propyl cellulose, ethyl propyl cellulose, hydroxymethyl ethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose and the like.
  • the cellulose ether one of these may be used alone, or two or more may be used in combination.
  • the cellulose resin is preferably ethyl cellulose.
  • content of the cellulose resin in a conductive composition is not specifically limited, It is preferable to adjust so that the printability of a conductive composition may become favorable.
  • the content of the cellulose resin is preferably 0.1% by mass to 4% by mass with respect to the entire conductive composition.
  • content of a cellulose resin is 0.1 mass% or more, the adhesiveness of the conductor and base material which bake an electroconductive composition, and a base material can be improved more.
  • content of a cellulose resin is 4 mass% or less, it can suppress that the fluidity
  • the content of the cellulose resin is 4% by mass or less, the relative content of the metal component in the conductor is increased, so that the conductivity of the conductor can be improved.
  • the content of the cellulose resin is more preferably 0.1% by mass to 2% by mass with respect to the entire conductive composition.
  • the conductive composition of the present embodiment may contain an organic solvent in order to uniformly disperse metal nanoparticles, metal particles, a thermosetting resin, a curing agent, and a cellulose resin.
  • the organic solvent is not particularly limited as long as it can highly disperse metal nanoparticles and metal particles and can dissolve a thermosetting resin, a curing agent, and a cellulose resin.
  • the organic solvent it is preferable to use one having a total number of carbons of 8 to 16, having a hydroxyl group, and further having a boiling point of 280 ° C. or less.
  • diethylene glycol monoethyl ether acetate (C8, boiling point 218 ° C.), terpineol (C10, boiling point 219 ° C.), dihydroterpineol (C10, boiling point 220 ° C.), texanol (C12, boiling point 260 ° C.) as an organic solvent
  • At least one selected from the group consisting of 2,4-dimethyl-1,5-pentadiol (C9, boiling point 150 ° C.) and butyl carbitol (C8, boiling point 230 ° C.) can be used.
  • isophorone (boiling point 215 ° C), ethylene glycol (boiling point 197 ° C), butyl carbitol acetate (boiling point 247 ° C), 2,2,4-trimethyl-1,3-pentanediol diisobutyrate ( It is also possible to use at least one selected from the group consisting of C16, boiling point 280 ° C.).
  • the addition amount of the organic solvent in the conductive composition is not particularly limited, it is preferable to adjust the conductive composition so as to have a viscosity that can be applied by a screen printing method or the like.
  • the content of the organic solvent is preferably 10% by mass to 25% by mass with respect to the entire conductive composition.
  • the conductive composition of the present embodiment has printing characteristics and conductor characteristics such as an antifoaming agent, a surfactant, and a rheology modifier within a range not adversely affecting the dispersion stability of the paste and the performance of the conductor after firing. It may contain additives to improve.
  • the specific resistance of a conductor formed by applying and baking the conductive composition on a substrate is preferably 5.0 ⁇ 10 ⁇ 6 ⁇ ⁇ cm or less.
  • the specific resistance of a conductor can be measured according to JIS K 7194 (The resistivity test method by the 4-probe method of electroconductive plastic). Specifically, the resistivity of the conductor can be measured by a four probe resistance measuring device.
  • the conductor when the tape having an adhesive strength of 3.9 N / 10 mm to 39 N / 10 mm is pressure-bonded to the conductor and peeled, it is preferable that the conductor does not peel from the substrate. Specifically, when the conductor is not peeled off from the substrate, when the tape is crimped to the conductor and peeled off, the conductor peeled off from the substrate can not be visually confirmed on the tape side, or the wiring board side In the case where the peeling of the conductor could not be confirmed visually. Since the conductor formed by applying and baking the conductive composition on a substrate has such characteristics, the adhesion of the conductor to the substrate is sufficient, so that the wiring board can be miniaturized and thinned.
  • the adhesive strength of the tape is preferably 4.3 N / 10 mm or more and 39 N / 10 mm or less, and more preferably 5.3 N / 10 mm or more and 38 N / 10 mm or less.
  • the conductive composition is composed of metal components such as metal nanoparticles and metal particles, and resin components such as a thermosetting resin, a curing agent, and a cellulose resin. And a conductor is formed by baking after apply
  • solder is easy to bond to metal, it has characteristics that it is difficult to bond to resin. Therefore, due to the resin component, the wettability between the conductor and the solder may be reduced at the time of mounting, making it difficult to form a fillet shape, or a solder ball may be formed. And in such a case, the joint strength of a conductor and mounting components may not be satisfied.
  • the total content of the thermosetting resin and the curing agent is preferably 0.1% by mass to 6% by mass with respect to the entire conductive composition.
  • the total content is 0.1% by mass or more, the adhesion between the conductor formed by firing the conductive composition and the substrate can be further improved.
  • the total content is 6% by mass or less, the relative metal component content in the conductor increases, so the conductivity of the conductor can be improved.
  • the total content of the thermosetting resin and the curing agent is more preferably 0.1% by mass to 5% by mass, and 0.1% by mass to 4% by mass with respect to the entire conductive composition. And more preferably 0.1% by mass to 2% by mass.
  • the conductive composition of the present embodiment has metal nanoparticles having an average particle size of 30 nm to 600 nm, metal particles having an average particle size larger than the metal nanoparticles, and an oxirane ring in the molecule. It contains a thermosetting resin, a curing agent, and a cellulose resin.
  • coating and baking an electroconductive composition to a base material is 5.0 * 10 ⁇ -6 > ohm * cm or less, and the adhesive force is 3.9 N / 10 mm-39 N /
  • the 10 mm tape is crimped to the conductor and peeled off, the conductor does not peel off from the substrate. Therefore, it is possible to obtain a conductor having a specific resistance equivalent to that of silver bulk and good adhesion to a substrate. Therefore, it becomes possible to apply to the wiring board for cars.
  • the conductor formed by firing the conductive composition of the present embodiment has good solder wettability. Therefore, when a component is mounted on a conductor using solder, sufficient mounting strength can be obtained.
  • the wiring board according to the present embodiment includes a conductor obtained from the above-described conductive composition.
  • the conductor obtained from the conductive composition of the present embodiment has a specific resistance of 5.0 ⁇ 10 ⁇ 6 ⁇ ⁇ cm or less and an adhesive strength of 3.9 N / 10 mm to 39 N / 10 mm.
  • the tape shows good adhesion.
  • the above-mentioned wiring board has adhesiveness which can endure long-term use, and since it can raise the amount of current which flows through a conductor, it can be used suitably for cars.
  • the wiring board of the present embodiment can be obtained by applying a conductive composition on a base material in a desired shape and then baking it.
  • the base material that can be used for the wiring board is not particularly limited, and an electrically insulating film or plate can be used. Such a base material is flexible and can cope with bending or the like according to the place of use.
  • the material of the substrate is not particularly limited. For example, from the group consisting of polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (PP), polybutylene terephthalate (PBT) At least one selected can be used.
  • the method for applying the conductive composition on a substrate is not particularly limited, and the method can be performed by a conventionally known method such as flexographic printing, gravure printing, gravure offset printing, offset printing, screen printing, rotary screen printing, and the like.
  • coating a conductive composition on a base material is not specifically limited, either.
  • the substrate coated with the conductive composition is preferably exposed to hot air of 140 ° C. or higher. Thereby, the organic solvent etc. in a conductive composition are removed, and since a metal nanoparticle and metal particles sinter, a highly conductive conductor can be obtained.
  • the baking method is not limited to the above-mentioned hot-air baking, For example, plasma baking, light baking, pulse wave baking can also be applied.
  • the wiring board provided with the conductor obtained from the conductive composition may be provided with an insulating cover material for covering and protecting the surface of the conductor.
  • An insulating film or a resist can be used as the insulating cover material.
  • PET polyethylene terephthalate
  • PEN polyethylene naphthalate
  • PC polycarbonate
  • PP polypropylene
  • PBT polybutylene terephthalate
  • PU polyurethane
  • the resist is preferably a thermosetting resist or a UV curable resist, and particularly preferably an epoxy resist or a urethane resist.
  • the conductive composition of each example is obtained by stirring metal nanoparticles, metal particles, thermosetting resin, curing agent, resin and organic solvent using the rotation and revolution stirrer at the compounding ratio shown in Tables 1 to 5.
  • the materials used as the raw material of the conductive composition of each example are as follows.
  • Silver nanoparticles having an average particle size of 25 nm, 30 nm, 70 nm, 350 nm, 600 nm and 700 nm, respectively
  • Silver particles having an average particle size of 1.0 ⁇ m, 3.0 ⁇ m, 5.0 ⁇ m and 6.0 ⁇ m, respectively
  • thermosetting resin -Bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation, jER (registered trademark) 828 -Bisphenol F type epoxy resin DIC Corporation EPICLON (registered trademark) 830 -Aliphatic epoxy resin, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., PG-207GS (polypropylene glycol diglycidyl ether) ⁇ Novolak type epoxy resin Made by Nippon Steel & Sumikin Chemical Co., Ltd., YDPN-638 (phenol novolac type epoxy resin) ⁇ Phenolic resin Gunei Chemical Industry Co., Ltd. PS-2608 Urethane resin Arakawa Chemical Industries, Ltd., Uuliano (registered trademark) KL-422
  • the specific resistance of the conductor was measured with reference to JIS K 7194.
  • a four-point probe resistance measurement device (a resistivity measurement device Sigma-5 + manufactured by NPP Inc.) was used.
  • a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so as to be 1 mm wide by 10 cm thick and 30 ⁇ m wide after firing.
  • the circuit board-printed polyimide film was allowed to stand at room temperature for 30 minutes and then fired at 140 ° C. for 30 minutes with hot air to produce a wiring board.
  • the surface resistance was measured at three points of 1 cm from each end and 5 cm at the center. The surface resistance was measured with the needle placed parallel to the circuit.
  • Adhesion 1 The adhesion of the conductive composition to the polyimide film was evaluated by a peeling test using a tape having an adhesive strength of 3.9 N / 10 mm to 5.7 N / 10 mm.
  • a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so as to be 1 mm wide by 10 cm thick and 30 ⁇ m wide after firing.
  • the circuit board-printed circuit board was fabricated by allowing the polyimide film printed with the circuit to stand for 30 minutes at room temperature and then firing at 140 ° C. for 30 minutes with hot air.
  • the tape used is an aluminum tape No. 5 manufactured by Nichiban Co., Ltd. with an adhesive strength of 5.30 N / 10 mm. 950 was used.
  • Judgment criteria No peeling off of printing observed (when the peeled circuit can not be confirmed on the tape side, and when peeling of the circuit can not be visually confirmed on the wiring board side)
  • X Peeling of printing is observed (when the peeled circuit can be confirmed on the tape side, or the peeling of the circuit can be visually confirmed on the wiring board side)
  • the blur of the printing was evaluated as follows. First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that the size after firing was 1 mm in width, 10 cm in length, and 30 ⁇ m in thickness. Next, the circuit board-printed polyimide film was allowed to stand at room temperature for 30 minutes and then fired at 140 ° C. for 30 minutes with hot air to produce a wiring board. Then, in the obtained wiring board, it was visually evaluated whether or not the printing of the circuit was blurred. ⁇ Judgment criteria ⁇ : No blur ⁇ : There is blur
  • the mesh marks on the print were evaluated as follows. First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that the size after firing was 1 mm in width, 10 cm in length, and 30 ⁇ m in thickness. Next, the circuit-printed polyimide film was allowed to stand at room temperature for 10 minutes, and then whether or not there was a mesh mark on the surface of the printed portion was confirmed with a microscope to evaluate the mesh mark. ⁇ Judgment criteria ⁇ : no mesh marks ⁇ : mesh marks
  • the squeegee stickiness at the time of printing was evaluated as follows. First, using a screen printer, three circuits were printed with the conductive composition obtained in each example on a polyimide film so that the size after firing was 1 mm in width, 10 cm in length, and 30 ⁇ m in thickness. After printing, the squeegee was raised and the appearance of the adhesion of the conductive composition to the squeegee was evaluated.
  • the conductive composition of each example is obtained by stirring metal nanoparticles, metal particles, thermosetting resin, curing agent, resin and organic solvent using the rotation and revolution stirrer at the compounding ratio shown in Tables 6 to 10. Prepared.
  • the same material as that of Example 1 was used as the material of the conductive composition of each example.
  • the conductive compositions of Comparative Examples 2-2, 2-4 to 2-6 and 2-8 to 2-13, respectively, are Comparative Examples 1-2, 1-4 to 1-6 and 1-8 to 1, respectively.
  • the composition is the same as the conductive composition of -13.
  • Adhesion 2 a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that after firing, the width was 1 mm, length 10 cm, thickness 30 ⁇ m.
  • the circuit board-printed circuit board was fabricated by allowing the polyimide film printed with the circuit to stand for 30 minutes at room temperature and then firing at 140 ° C. for 30 minutes with hot air.
  • the tape used was a 3M manufactured VHB super-strong double-sided tape with an adhesive strength of 38 N / 10 mm and a low VOC type, product number Y-4825 K-08.
  • Judgment criteria No peeling off of printing observed (when the peeled circuit can not be confirmed on the tape side, and when peeling of the circuit can not be visually confirmed on the wiring board side)
  • X Peeling of printing is observed (when the peeled circuit can be confirmed on the tape side, or the peeling of the circuit can be visually confirmed on the wiring board side)
  • solder wettability First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that after firing, the width was 1 mm, length 10 cm, thickness 30 ⁇ m. Next, the circuit board-printed polyimide film was allowed to stand at room temperature for 30 minutes and then fired at 140 ° C. for 30 minutes with hot air to produce a wiring board.
  • a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that after firing, the width was 1 mm, length 10 cm, thickness 30 ⁇ m.
  • the circuit board-printed polyimide film was allowed to stand at room temperature for 30 minutes and then fired at 140 ° C. for 30 minutes with hot air to produce a wiring board.
  • a 3216 size 0 ⁇ resistor was soldered to the obtained Ag thin film on the wiring board using Sn—Bi based low temperature solder. And the shear strength of the obtained circuit was measured using a bond tester (manufactured by Nordson Dage, SERIES 4000).
  • ⁇ Judgment criteria ⁇ : The share strength is 50N or more ⁇ : The share strength is 20N or more and less than 50N ⁇ : The share strength is less than 20N-: The share strength can not be measured
  • the specific resistance of the conductor is small, and the adhesion of the conductor to the substrate is also good. Met.
  • the conductors of these examples are also good in the evaluation of the solder wettability and the mounting strength, and are excellent in the mounting property.
  • a conductive composition capable of obtaining a conductor having the same specific resistance as silver bulk and good adhesion to a substrate and a wiring board using the conductive composition. can do.

Abstract

This conductive composition contains: metal nanoparticles which have an average particle diameter of from 30 nm to 600 nm; metal particles which have a larger average particle diameter than the metal nanoparticles; a thermosetting resin which has an oxirane ring in each molecule; a curing agent; and a cellulose resin. A conductor, which is formed by applying this conductive composition to a base material and firing the applied conductive composition, has a specific resistance of 5.0 × 10-6 Ω·cm or less; and if a tape having an adhesive force of from 3.9 N/10 mm to 39 N/10 mm is compression bonded to the conductor and is subsequently separated therefrom, the conductor is not separated from the base material.

Description

導電性組成物及びそれを用いた配線板Conductive composition and wiring board using the same
　本発明は、導電性組成物及びそれを用いた配線板に関する。詳細には、本発明は、銀バルクと同等の比抵抗であり、基材への密着性が良好である導体を得ることが可能な導電性組成物及び当該導電性組成物を用いた配線板に関する。 The present invention relates to a conductive composition and a wiring board using the same. Specifically, the present invention provides a conductive composition capable of obtaining a conductor having a resistivity equivalent to that of silver bulk and good adhesion to a substrate, and a wiring board using the conductive composition. About.
　近年、自動車の配索スペースの減少により、ワイヤーハーネス及びその周辺部品の小型化、薄型化、立体化等を達成することが可能なフレキシブルプリント配線板が求められている。特に、ルームミラーの近傍に設けられ、車室の前方中心にあるマップランプは薄型化が求められている。つまり、自動ブレーキ車両や自動運転車両の進化と共に、カメラやセンサモジュールの機能集約が進み、これらをマップランプの裏面へ設置することが求められるため、マップランプの薄型化が必須となる。そのため、マップランプを薄型化するために、上述のようなフレキシブルプリント配線板のニーズが高まっている。 BACKGROUND In recent years, flexible printed wiring boards capable of achieving downsizing, thinning, three-dimensionalization, and the like of a wire harness and its peripheral parts have been required due to a reduction in a wiring space of a car. In particular, a map lamp provided near the rearview mirror and centered on the front of the cabin is required to be thin. That is, with the evolution of automatic braking vehicles and autonomous driving vehicles, the integration of functions of cameras and sensor modules advances, and these are required to be installed on the back of map lamps, so it is essential to make map lamps thinner. Therefore, in order to reduce the thickness of the map lamp, the need for the flexible printed wiring board as described above is increasing.
　小型化、薄型化、立体化等の要求に対応するフレキシブルなプリント配線板として、電気絶縁性を持った薄く柔らかいベースフィルムと銅箔等の導電性金属とを貼り合わせた基材に、電気回路を形成したフレキシブルプリント配線板（ＦＰＣ）が知られている。ＦＰＣの回路は、通常、サブトラクト法と呼ばれる方法で製造される。例えば、ポリイミドフィルムに銅等の金属箔を貼り合わせ、その金属箔をエッチングすることで回路を形成することができる。このようなサブトラクト法は、フォトリソグラフィ、エッチング、化学蒸着等の複雑で非常に長い工程を必要とし、スループットが非常に低いという問題がある。また、フォトリソグラフィ、エッチング等の工程においては、廃液等の環境に対する課題が常に問題視されている。 As a flexible printed wiring board that meets the requirements for miniaturization, thinning, and three-dimensionalization, an electric circuit is used as a base on which a thin and soft base film with electrical insulation and a conductive metal such as copper foil are bonded. A flexible printed wiring board (FPC) is known. The circuit of the FPC is usually manufactured by a method called a subtraction method. For example, a circuit can be formed by bonding a metal foil such as copper to a polyimide film and etching the metal foil. Such a subtraction method requires complicated and very long steps such as photolithography, etching, chemical vapor deposition and the like, and has a problem that the throughput is very low. In addition, in processes such as photolithography and etching, there are always problems regarding the environment such as waste liquid.
　上記課題を解決するために、サブトラクト法の逆で、絶縁板上に導体パターンを形成していくアディティブ法が検討されている。この方法の種類は複数存在し、メッキ、導電性組成物等を印刷して構成するもの、基材の必要部分に金属を蒸着させるもの、ポリイミドで被覆された電線を基材上に接着布線するもの、予め形成したパターンを基材に接着するもの等が主として存在する。 In order to solve the above problems, an additive method is being studied in which a conductor pattern is formed on an insulating plate, which is the reverse of the subtract method. There are multiple types of this method, plating, printing by using a conductive composition, etc., deposition of metal on the necessary part of the substrate, and electric wire coated with polyimide on the substrate. There are mainly ones that adhere to the substrate, and the ones that adhere a preformed pattern to the substrate.
　これらのアディティブ法の中でも最もスループットが高い工法として、印刷工法が挙げられる。印刷工法は、主にフィルムを基材とし、さらに導電性インクや導電性組成物を導線材料として用い、そこに絶縁フィルムやレジスト等を合わせることで、電気回路を成立させている。このような導電性インクや導電性組成物は、金属成分、有機溶剤、還元剤及び接着剤等で構成され、塗布後に焼成することで導体が形成され、導通を可能にしている。 Among these additive methods, the printing method is mentioned as the method with the highest throughput. The printing method mainly uses a film as a base material, and further uses a conductive ink or a conductive composition as a conducting wire material, and combines an insulating film, a resist and the like there to form an electric circuit. Such a conductive ink or conductive composition is composed of a metal component, an organic solvent, a reducing agent, an adhesive and the like, and a conductor is formed by baking after application to enable conduction.
　例えば、特許文献１では、バインダー樹脂としての熱可塑性樹脂及び熱硬化性樹脂と、硬化剤と、金属粒子と、を含有する導電性組成物が開示されている。また、特許文献２では、銀粒子からなる固形分と溶剤とを混練してなる金属ペーストが開示されている。特許文献２では、粒径１００～２００ｎｍの銀粒子を所定量含み、かつ、銀粒子全体の平均粒径が６０～８００ｎｍであり、さらに、添加剤として、数平均分子量が所定の範囲である高分子量エチルセルロースを含む金属ペーストが開示されている。 For example, Patent Document 1 discloses a conductive composition containing a thermoplastic resin and a thermosetting resin as a binder resin, a curing agent, and metal particles. Moreover, in patent document 2, the metal paste formed by knead | mixing solid content which consists of silver particles, and a solvent is disclosed. Patent Document 2 contains a predetermined amount of silver particles having a particle diameter of 100 to 200 nm, and the average particle diameter of the whole silver particles is 60 to 800 nm, and further, a high number average molecular weight is a predetermined range as an additive. A metal paste comprising molecular weight ethylcellulose is disclosed.
　特許文献３では、銀化合物と、所定のアミン混合液とを混合して、銀化合物及び上記アミンを含む錯化合物を生成させ、上記錯化合物を加熱して熱分解させて、銀ナノ粒子を形成することが開示されている。そして、特許文献３では、上記銀ナノ粒子と、有機溶剤とを含む銀塗料組成物が開示されている。特許文献４では、エポキシ樹脂、硬化剤、導電粉及び溶剤を含む硬化性導電ペーストが開示されている。特許文献５では、（Ａ）導電性フィラーと、（Ｂ）熱硬化性バインダーと、（Ｃ）セルロース樹脂と、（Ｄ）場合によりアクリロニトリル・ブタジエン共重合体を含む熱硬化型導電性ペーストが開示されている。 In Patent Document 3, a silver compound and a predetermined amine mixed solution are mixed to form a complex compound containing the silver compound and the above amine, and the complex compound is heated and thermally decomposed to form silver nanoparticles. It is disclosed that. And in patent documents 3, the silver paint constituent containing the above-mentioned silver nanoparticle and an organic solvent is indicated. Patent Document 4 discloses a curable conductive paste containing an epoxy resin, a curing agent, a conductive powder and a solvent. Patent Document 5 discloses a thermosetting conductive paste containing (A) a conductive filler, (B) a thermosetting binder, (C) a cellulose resin, and (D) optionally an acrylonitrile-butadiene copolymer. It is done.
特開２０１３－１３４９１４号公報JP 2013-134914 A 国際公開第２０１７／０３３９１１号International Publication No. 2017/033911 特開２０１３－１４２１７３号公報JP, 2013-142173, A 特開２０００－２３９６３６号公報JP 2000-239636 A 特開２０１２－８４４４０号公報JP 2012-84440 A
　樹脂成分や接着剤は、導電性組成物に一定量以上添加されていなければ、基材に対する導体の密着性が得られない。一方、樹脂成分や接着剤が、導電性組成物に一定量以上添加されていると、金属粒子の接触点が減少してしまい、導体の比抵抗が増加してしまう。そのため、特許文献１～５の導電性組成物を用いたとしても、銀バルクと同等の比抵抗であり、基材への密着性が良好である導体を得ることが可能な導電性組成物を得ることが困難であった。したがって、フレキシブルプリント配線板に求められている密着性を満たし、かつ、比抵抗が十分に小さい自動車用途向けの配線板を得ることは困難であった。 If the resin component and the adhesive are not added to the conductive composition in a certain amount or more, adhesion of the conductor to the substrate can not be obtained. On the other hand, when the resin component and the adhesive are added to the conductive composition in a fixed amount or more, the contact points of the metal particles decrease, and the specific resistance of the conductor increases. Therefore, even if the conductive compositions of Patent Documents 1 to 5 are used, it is possible to obtain a conductive composition capable of obtaining a conductor having the same specific resistance as silver bulk and good adhesion to a substrate. It was difficult to get. Therefore, it has been difficult to obtain a wiring board for automotive applications that satisfies the adhesion required for flexible printed wiring boards and has a sufficiently small specific resistance.
　本発明は、このような従来技術が有する課題に鑑みてなされたものである。そして本発明の目的は、銀バルクと同等の比抵抗であり、基材への密着性が良好である導体を得ることが可能な導電性組成物及び当該導電性組成物を用いた配線板を提供することにある。 The present invention has been made in view of the problems that such prior art has. An object of the present invention is a conductive composition capable of obtaining a conductor having a specific resistance equivalent to that of silver bulk and good adhesion to a substrate, and a wiring board using the conductive composition. It is to provide.
　本発明の第１の態様に係る導電性組成物は、３０ｎｍ～６００ｎｍの平均粒子径を有する金属ナノ粒子と、金属ナノ粒子より大きい平均粒子径を有する金属粒子と、分子内にオキシラン環を有する熱硬化性樹脂と、硬化剤と、セルロース樹脂と、を含有する導電性組成物であって、導電性組成物を基材に塗布及び焼成して形成された導体の比抵抗が５．０×１０－６Ω・ｃｍ以下であり、かつ、粘着力が３．９Ｎ／１０ｍｍ～３９Ｎ／１０ｍｍのテープを導体に圧着して剥離した際に基材から導体が剥離しない。 The conductive composition according to the first aspect of the present invention comprises metal nanoparticles having an average particle size of 30 nm to 600 nm, metal particles having an average particle size larger than the metal nanoparticles, and an oxirane ring in the molecule. A conductive composition comprising a thermosetting resin, a curing agent, and a cellulose resin, wherein the specific resistance of a conductor formed by applying and baking the conductive composition to a substrate is 5.0 × When the tape having an adhesion of 3.9 N / 10 mm to 39 N / 10 mm or less and 10 -6 Ω · cm or less is pressure-bonded to the conductor and peeled off, the conductor does not peel off from the substrate.
　本発明の第２の態様に係る導電性組成物は、第１の態様の導電性組成物に関し、熱硬化性樹脂はビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ノボラック型エポキシ樹脂、グリシジルアミン型エポキシ樹脂及び脂肪族型エポキシ樹脂からなる群より選択される少なくとも一種である。 The conductive composition according to the second aspect of the present invention relates to the conductive composition according to the first aspect, wherein the thermosetting resin is a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolac epoxy resin, glycidyl amine And at least one selected from the group consisting of epoxy resins and aliphatic epoxy resins.
　本発明の第３の態様に係る導電性組成物は、第１又は２の態様の導電性組成物に関し、硬化剤は、窒素を含む五員複素環式芳香族化合物である。 The conductive composition according to the third aspect of the present invention relates to the conductive composition of the first or second aspect, wherein the curing agent is a five-membered heterocyclic aromatic compound containing nitrogen.
　本発明の第４の態様に係る導電性組成物は、第１～第３のいずれかの態様の導電性組成物に関し、熱硬化性樹脂と硬化剤の含有量の比は、質量比で１：１～４：１である。 The conductive composition according to the fourth aspect of the present invention relates to the conductive composition according to any one of the first to third aspects, wherein the ratio of the content of the thermosetting resin to the content of the curing agent is 1 in mass ratio : 1 to 4: 1.
　本発明の第５の態様に係る導電性組成物は、第１～第４のいずれかの態様の導電性組成物に関し、導電性組成物全体に対し、セルロース樹脂の含有量は０．１質量％～４質量％である。 The conductive composition according to the fifth aspect of the present invention relates to the conductive composition according to any one of the first to fourth aspects, wherein the content of the cellulose resin is 0.1 mass with respect to the entire conductive composition. % To 4% by mass.
　本発明の第６の態様に係る導電性組成物は、第１～第５のいずれかの態様の導電性組成物に関し、導電性組成物全体に対し、熱硬化性樹脂と硬化剤の合計の含有量は０．１質量％～６質量％である。 The conductive composition according to the sixth aspect of the present invention relates to the conductive composition according to any one of the first to fifth aspects, wherein a total of a thermosetting resin and a curing agent relative to the entire conductive composition. The content is 0.1% by mass to 6% by mass.
　本発明の第７の態様に係る導電性組成物は、第１～第６のいずれかの態様の導電性組成物に関し、導電性組成物全体に対し、熱硬化性樹脂と硬化剤の合計の含有量は０．１質量％～５質量％である。 The conductive composition according to a seventh aspect of the present invention relates to the conductive composition according to any one of the first to sixth aspects, wherein the total of the thermosetting composition and the curing agent relative to the entire conductive composition. The content is 0.1% by mass to 5% by mass.
　本発明の第８の態様に係る導電性組成物は、第１～第７のいずれかの態様の導電性組成物に関し、導電性組成物全体に対し、熱硬化性樹脂と硬化剤の合計の含有量は０．１質量％～２質量％である。 The conductive composition according to the eighth aspect of the present invention relates to the conductive composition according to any one of the first to seventh aspects, wherein the total of the thermosetting resin and the curing agent relative to the entire conductive composition. The content is 0.1% by mass to 2% by mass.
　本発明の第９の態様に係る導電性組成物は、第１～第８のいずれかの態様の導電性組成物に関し、金属粒子の平均粒子径が１μｍ～５μｍである。 The conductive composition according to a ninth aspect of the present invention relates to the conductive composition according to any one of the first to eighth aspects, wherein the metal particles have an average particle size of 1 μm to 5 μm.
　本発明の第１０の態様に係る配線板は、第１～第９のいずれかの態様の導電性組成物より得られる導体を備える。 A wiring board according to a tenth aspect of the present invention includes a conductor obtained from the conductive composition according to any one of the first to ninth aspects.
［導電性組成物］
　本実施形態の導電性組成物は、金属ナノ粒子と、金属粒子と、熱硬化性樹脂と、硬化剤と、セルロース樹脂と、を含有する。以下、各構成について詳細に説明する。 [Conductive composition]
The conductive composition of the present embodiment contains metal nanoparticles, metal particles, a thermosetting resin, a curing agent, and a cellulose resin. Each component will be described in detail below.
　本実施形態の導電性組成物は、３０ｎｍ～６００ｎｍの平均粒子径を有する金属ナノ粒子を含有する。通常、金属粒子の径が小さくなるに従って粒子表面に存在する金属原子数が多くなるため、金属の融点が低下する。そのため、導電性組成物にこのような金属ナノ粒子を用いることにより、比較的低温で導体を形成することが可能となる。また、金属ナノ粒子の平均粒子径が３０ｎｍ～６００ｎｍであることにより、金属粒子の隙間を金属ナノ粒子で充填することができる。そのため、金属ナノ粒子と金属粒子が焼結することで緻密な焼結体となるため、導電性組成物の焼成により得られる導体の導電性を高めることが可能となる。なお、より緻密な焼結体を形成し、導電性を高める観点から、金属ナノ粒子の平均粒子径は７０ｎｍ～６００ｎｍであることがより好ましい。また、本明細書において、金属ナノ粒子の平均粒子径は、動的光散乱法で測定したメディアン径（５０％径、Ｄ５０）をいう。 The conductive composition of the present embodiment contains metal nanoparticles having an average particle size of 30 nm to 600 nm. Usually, as the diameter of the metal particles decreases, the number of metal atoms present on the surface of the particles increases, so the melting point of the metal decreases. Therefore, by using such metal nanoparticles for the conductive composition, it becomes possible to form a conductor at a relatively low temperature. In addition, when the average particle diameter of the metal nanoparticles is 30 nm to 600 nm, the gaps between the metal particles can be filled with the metal nanoparticles. Therefore, since the metal nanoparticles and the metal particles are sintered to form a dense sintered body, it is possible to enhance the conductivity of the conductor obtained by firing the conductive composition. The average particle diameter of the metal nanoparticles is more preferably 70 nm to 600 nm from the viewpoint of forming a denser sintered body and enhancing the conductivity. Moreover, in the present specification, the average particle size of metal nanoparticles refers to the median diameter (50% diameter, D50) measured by the dynamic light scattering method.
　金属ナノ粒子を構成する金属は、特に限定されないが、金、銀、銅、白金、パラジウム、ロジウム、ルテニウム、イリジウム、オスミウム、タングステン、ニッケル、タンタル、ビスマス、鉛、インジウム、錫、亜鉛及びチタンからなる群より選択される少なくとも一種を含有することが好ましい。また、金属ナノ粒子を構成する金属は、金、銀、銅、白金、パラジウム、ロジウム、ルテニウム、イリジウム、オスミウム、タングステン、ニッケル、タンタル、ビスマス、鉛、インジウム、錫、亜鉛及びチタンからなる群より選択される少なくとも一種からなることがより好ましい。さらに、金属ナノ粒子を構成する金属は、金、銀、銅及び白金からなる群より選択される少なくとも一種を含有することが好ましい。これらのような金属ナノ粒子を用いることにより、微細な配線を形成することができる。さらに焼成後の導体の抵抗値を低減でき、導体の表面平滑性も高めることが可能となる。これらの金属の中でも、導電性組成物の焼成により容易に還元されて緻密な焼結体を形成し、得られる導体の比抵抗を低減できる観点から、銀を用いることが好ましい。 The metal constituting the metal nanoparticles is not particularly limited, but may be gold, silver, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc and titanium It is preferable to contain at least one selected from the group consisting of Also, the metal constituting the metal nanoparticles is a group consisting of gold, silver, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc and titanium It is more preferable to consist of at least one selected. Furthermore, the metal constituting the metal nanoparticles preferably contains at least one selected from the group consisting of gold, silver, copper and platinum. Fine wiring can be formed by using such metal nanoparticles. Furthermore, the resistance value of the conductor after firing can be reduced, and the surface smoothness of the conductor can be enhanced. Among these metals, it is preferable to use silver from the viewpoint of being able to be easily reduced by firing of the conductive composition to form a dense sintered body and to reduce the specific resistance of the obtained conductor.
　本実施形態に係る導電性組成物は、上述の金属ナノ粒子に加え、金属ナノ粒子より大きい平均粒子径を有する金属粒子を含有している。このような金属粒子を用いることにより、焼成後の導体を緻密化し、比抵抗を低減することができる。 The conductive composition according to the present embodiment contains metal particles having an average particle size larger than the metal nanoparticles, in addition to the above-described metal nanoparticles. By using such metal particles, the conductor after firing can be densified to reduce the specific resistance.
　金属粒子の平均粒子径は、１μｍ～５μｍであることが好ましい。金属粒子の平均粒子径がこの範囲内であることにより、導体の導電性を高めることが可能となる。また、後述するように、導電性組成物をスクリーン印刷法により絶縁性の基材に塗布する場合でも、スクリーン印刷のメッシュに金属粒子が詰まるおそれが少ないため、微細な回路を効率的に形成することが可能となる。なお、本明細書において、金属粒子の平均粒子径は、動的光散乱法で測定したメディアン径（５０％径、Ｄ５０）をいう。 The average particle size of the metal particles is preferably 1 μm to 5 μm. When the average particle size of the metal particles is in this range, the conductivity of the conductor can be enhanced. Further, as described later, even when the conductive composition is applied to the insulating base material by the screen printing method, there is little possibility that the metal particles are clogged with the screen printing mesh, so that a fine circuit is efficiently formed. It becomes possible. In the present specification, the average particle size of the metal particles refers to the median diameter (50% diameter, D50) measured by the dynamic light scattering method.
　金属粒子を構成する金属は、金属ナノ粒子と同様に、金、銀、銅、白金、パラジウム、ロジウム、ルテニウム、イリジウム、オスミウム、タングステン、ニッケル、タンタル、ビスマス、鉛、インジウム、錫、亜鉛及びチタンからなる群より選択される少なくとも一種を含有することが好ましい。また、金属粒子を構成する金属は、金、銀、銅、白金、パラジウム、ロジウム、ルテニウム、イリジウム、オスミウム、タングステン、ニッケル、タンタル、ビスマス、鉛、インジウム、錫、亜鉛及びチタンからなる群より選択される少なくとも一種からなることがより好ましい。さらに、金属粒子を構成する金属は、金、銀、銅及び白金からなる群より選択される少なくとも一種を含有することが好ましい。これらの金属からなる金属粒子を用いることにより、焼成後の導体の抵抗値を低減でき、導体の表面平滑性も高めることが可能となる。これらの金属の中でも、導電性組成物の焼成により容易に還元されて緻密な焼結体を形成し、得られる導体の比抵抗を低減できる観点から、銀を用いることが好ましい。 The metal constituting the metal particle is, like the metal nanoparticle, gold, silver, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc and titanium It is preferable to contain at least one selected from the group consisting of The metal constituting the metal particles is selected from the group consisting of gold, silver, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc and titanium It is more preferable that it consists of at least 1 type. Further, the metal constituting the metal particles preferably contains at least one selected from the group consisting of gold, silver, copper and platinum. By using the metal particle which consists of these metals, the resistance value of the conductor after baking can be reduced, and it becomes possible to also improve the surface smoothness of a conductor. Among these metals, it is preferable to use silver from the viewpoint of being able to be easily reduced by firing of the conductive composition to form a dense sintered body and to reduce the specific resistance of the obtained conductor.
　本実施形態の導電性組成物において、金属ナノ粒子と金属粒子との割合は特に限定されないが、例えば質量比で１：９～９：１であることが好ましい。金属ナノ粒子と金属粒子との割合がこの範囲内であることにより、緻密な焼結体からなり導電性が向上した導体を得ることが可能となる。なお、金属ナノ粒子の割合がこの範囲よりも低い場合には、得られる導体の比抵抗を満足することが難しくなる可能性がある。逆に、金属ナノ粒子の割合がこの範囲よりも高い場合には、導電性組成物の粘度が低下し、加工性を満足することが困難になる可能性がある。 In the conductive composition of the present embodiment, the ratio of the metal nanoparticles to the metal particles is not particularly limited, but, for example, the weight ratio is preferably 1: 9 to 9: 1. When the ratio of the metal nanoparticles to the metal particles is in this range, it is possible to obtain a conductor made of a dense sintered body and having improved conductivity. In addition, when the ratio of metal nanoparticles is lower than this range, it may be difficult to satisfy the specific resistance of the obtained conductor. Conversely, if the proportion of metal nanoparticles is higher than this range, the viscosity of the conductive composition may decrease, making it difficult to achieve processability.
　本実施形態に係る導電性組成物は、分子内にオキシラン環を有する熱硬化性樹脂を含有する。オキシランは、エチレンオキシドとも呼ばれ、三員環エーテルである。このような熱硬化性樹脂を用いることにより、導電性組成物を基材に塗布及び乾燥させて導体を形成した場合に、基材と導体との密着性を向上させることができる。 The conductive composition according to the present embodiment contains a thermosetting resin having an oxirane ring in the molecule. Oxyrane, also called ethylene oxide, is a three-membered cyclic ether. By using such a thermosetting resin, when the conductive composition is applied to a substrate and dried to form a conductor, the adhesion between the substrate and the conductor can be improved.
　分子内にオキシラン環を有する熱硬化性樹脂は、特に限定されないが、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ノボラック型エポキシ樹脂、グリシジルアミン型エポキシ樹脂及び脂肪族型エポキシ樹脂からなる群より選択される少なくとも一種であることが好ましい。 The thermosetting resin having an oxirane ring in the molecule is not particularly limited, but from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, glycidyl amine epoxy resin, and aliphatic epoxy resin Preferably, it is at least one selected.
　硬化剤は、導電性組成物に含まれる熱硬化性樹脂を硬化させることができれば、特に限定されず、例えば、イミダゾール系硬化剤、アミド系硬化剤、フェノール系硬化剤、アミン系硬化剤、酸無水物系硬化剤などを用いることができる。硬化剤は、これらのうちの一種を単独で使用してもよく、二種以上を組み合わせて使用してもよい。 The curing agent is not particularly limited as long as it can cure the thermosetting resin contained in the conductive composition, and, for example, an imidazole-based curing agent, an amide-based curing agent, a phenol-based curing agent, an amine-based curing agent, an acid An anhydride curing agent or the like can be used. As the curing agent, one of these may be used alone, or two or more may be used in combination.
　イミダゾール系硬化剤としては、例えば、イミダゾール、２－メチルイミダゾール、２－エチルイミダゾール、２－エチル－４－メチルイミダゾール、２－イソプロピルイミダゾール、２－フェニルイミダゾール、１－シアノエチル－２－ウンデシルイミダゾール、１－シアノ－２－フェニルイミダゾール、１－シアノエチル－２－ウンデシルイミダゾールトリメリテート、１－シアノエチル－２－フェニルイミダゾリウムトリメリテイトなどが挙げられる。 Examples of the imidazole-based curing agent include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-isopropylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate and the like.
　アミド系硬化剤としては、例えば、ジシアンジアミドなどが挙げられる。 Examples of the amide curing agent include dicyandiamide and the like.
　フェノール系硬化剤としては、例えば、フェノール樹脂などが挙げられる。 As a phenol-type curing agent, a phenol resin etc. are mentioned, for example.
　アミン系硬化剤としては、例えば、ジエチレントリアミン、トリエチレンテトラミン、テトラエチレンペンタミン及びＮ－アミノエチルピペラジンなどの脂肪族アミン、並びに、トルエンジアミン、キシレンジアミン、ジアミノジフェニルメタン、フェニレンジアミン及びジアミノジフェニルスルホンなどの芳香族アミンなどが挙げられる。 Examples of amine-based curing agents include aliphatic amines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and N-aminoethylpiperazine, and toluenediamine, xylenediamine, diaminodiphenylmethane, phenylenediamine and diaminodiphenylsulfone. Aromatic amines and the like can be mentioned.
　酸無水物系硬化剤としては、例えば、無水フタル酸、無水トリメリット酸、テトラヒドロ無水フタル酸、メチルテトラヒドロ無水フタル酸、メチルヘキサヒドロ無水フタル酸、ヘキサヒドロ無水フタル酸、無水ナジック酸などが挙げられる。 Examples of the acid anhydride curing agent include phthalic anhydride, trimellitic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, hexahydrophthalic anhydride, nadic anhydride and the like. .
　硬化剤は、窒素を含む五員複素環式芳香族化合物であることが好ましい。窒素を含む五員複素環式芳香族化合物は、炭素及び窒素を含み、五員環を有し、芳香族性を有する複素環式化合物である。このような硬化剤は、一般的に、硬化開始温度が１００℃以上となるため、導電性組成物を調製して基材などに塗布しても常温では硬化が開始しにくく、焼成してから硬化が開始されやすい。そのため、例えば配線板などの製造時において、導電性組成物のハンドリングが容易になる。窒素を含む五員複素環式芳香族化合物の硬化剤としては、例えば、上記のイミダゾール系硬化剤が挙げられる。 The curing agent is preferably a five-membered heterocyclic aromatic compound containing nitrogen. The nitrogen-containing five-membered heterocyclic aromatic compound is a heterocyclic compound containing carbon and nitrogen, having a five-membered ring, and having aromaticity. Since such a curing agent generally has a curing start temperature of 100 ° C. or higher, curing is difficult to start at ordinary temperature even if the conductive composition is prepared and applied to a base material, etc. It is easy to start curing. Therefore, the handling of the conductive composition becomes easy, for example, at the time of manufacturing a wiring board or the like. Examples of the curing agent of the nitrogen-containing five-membered heterocyclic aromatic compound include the above-mentioned imidazole curing agents.
　熱硬化性樹脂と硬化剤の含有量の比は、質量比で１：１～４：１であることが好ましい。熱硬化性樹脂と硬化剤の含有量の比を上記範囲内とすることにより、熱硬化性樹脂と硬化剤との反応性がより向上するため、導電性組成物の硬化を促進させることができる。なお、熱硬化性樹脂と硬化剤の含有量の比は、質量比で１：１～３：１であることがより好ましい。 The ratio of the content of the thermosetting resin to the curing agent is preferably 1: 1 to 4: 1 in mass ratio. By setting the ratio of the content of the thermosetting resin to the curing agent within the above range, the reactivity between the thermosetting resin and the curing agent is further improved, so that the curing of the conductive composition can be promoted. . The ratio by weight of the thermosetting resin to the curing agent is more preferably 1: 1 to 3: 1.
　本実施形態の導電性組成物は、セルロース樹脂を含有している。導電性組成物中にセルロース樹脂を均一に分散させることにより、導電性組成物の流動性が上昇し、導電性組成物の印刷適性が低下するのを抑制することができる。また、導電性組成物中にセルロース樹脂を均一に分散させることにより、熱硬化性樹脂及び硬化剤が互いに絡み合うため、導電性組成物を焼成してなる導体と基材との密着性を向上させることができる。 The conductive composition of the present embodiment contains a cellulose resin. By uniformly dispersing the cellulose resin in the conductive composition, the flowability of the conductive composition can be increased, and the printability of the conductive composition can be prevented from being lowered. Also, by uniformly dispersing the cellulose resin in the conductive composition, the thermosetting resin and the curing agent become entangled with each other, thereby improving the adhesion between the conductor formed by firing the conductive composition and the substrate. be able to.
　セルロース樹脂としては、セルロースエーテル、セルロースエステル、セルロースエーテルエステルなどが挙げられるが、セルロースエーテルを用いることが好ましい。セルロースエーテルは、セルロースへ一種のエーテル基が結合したセルロース単独エーテルと、二種以上のエーテル基が結合したセルロース混合エーテルがある。セルロース単独エーテルの具体例としては、メチルセルロース、エチルセルロース、プロピルセルロース、ヒドロキシメチルセルロース、ヒドロキシエチルセルロース、ヒドロキシプロピルセルロース、カルボキシメチルセルロースなどが挙げられる。セルロース混合エーテルの具体例として、メチルエチルセルロース、メチルプロピルセルロース、エチルプロピルセルロース、ヒドロキシメチルエチルセルロース、ヒドロキシプロピルメチルセルロース、ヒドロキシエチルメチルセルロース、ヒドロキシプロピルメチルセルロースなどが挙げられる。セルロースエーテルは、これらのうちの一種を単独で使用してもよく、二種以上を組み合わせて使用してもよい。なお、これらのなかでも、セルロース樹脂はエチルセルロースであることが好ましい。 As a cellulose resin, although a cellulose ether, a cellulose ester, a cellulose ether ester etc. are mentioned, it is preferable to use a cellulose ether. The cellulose ether includes cellulose single ether in which one kind of ether group is bonded to cellulose and cellulose mixed ether in which two or more kinds of ether groups are bonded. Specific examples of the cellulose single ether include methyl cellulose, ethyl cellulose, propyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and the like. Specific examples of the cellulose mixed ether include methyl ethyl cellulose, methyl propyl cellulose, ethyl propyl cellulose, hydroxymethyl ethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose and the like. As the cellulose ether, one of these may be used alone, or two or more may be used in combination. Among these, the cellulose resin is preferably ethyl cellulose.
　導電性組成物におけるセルロース樹脂の含有量は特に限定されないが、導電性組成物の印刷適性が良好になるように調整することが好ましい。具体的には、導電性組成物全体に対し、セルロース樹脂の含有量は０．１質量％～４質量％であることが好ましい。セルロース樹脂の含有量が０．１質量％以上の場合、導電性組成物を焼成してなる導体と基材との密着性をより向上させることができる。また、セルロース樹脂の含有量が４質量％以下の場合、導電性組成物の流動性が過度に上昇するのを抑制することができ、導電性組成物の印刷適性を向上させることができる。また、セルロース樹脂の含有量が４質量％以下の場合、導体中の相対的な金属成分の含有量が増加するため、導体の導電性を向上させることができる。なお、導電性組成物全体に対し、セルロース樹脂の含有量は０．１質量％～２質量％であることがより好ましい。 Although content of the cellulose resin in a conductive composition is not specifically limited, It is preferable to adjust so that the printability of a conductive composition may become favorable. Specifically, the content of the cellulose resin is preferably 0.1% by mass to 4% by mass with respect to the entire conductive composition. When content of a cellulose resin is 0.1 mass% or more, the adhesiveness of the conductor and base material which bake an electroconductive composition, and a base material can be improved more. Moreover, when content of a cellulose resin is 4 mass% or less, it can suppress that the fluidity | liquidity of a conductive composition raises too much, and can improve the printability of a conductive composition. Further, when the content of the cellulose resin is 4% by mass or less, the relative content of the metal component in the conductor is increased, so that the conductivity of the conductor can be improved. The content of the cellulose resin is more preferably 0.1% by mass to 2% by mass with respect to the entire conductive composition.
　本実施形態の導電性組成物は、金属ナノ粒子、金属粒子、熱硬化性樹脂、硬化剤及びセルロース樹脂を均一に分散させるために、有機溶剤を含有していてもよい。有機溶剤としては、金属ナノ粒子及び金属粒子を高分散させ、熱硬化性樹脂、硬化剤及びセルロース樹脂を溶解することが可能なものであれば特に限定されない。 The conductive composition of the present embodiment may contain an organic solvent in order to uniformly disperse metal nanoparticles, metal particles, a thermosetting resin, a curing agent, and a cellulose resin. The organic solvent is not particularly limited as long as it can highly disperse metal nanoparticles and metal particles and can dissolve a thermosetting resin, a curing agent, and a cellulose resin.
　有機溶剤としては、炭素総数が８～１６であり、ヒドロキシル基を有し、さらに沸点が２８０℃以下であるものを使用することが好ましい。具体的には、有機溶剤として、ジエチレングリコールモノエチルエーテルアセテート（Ｃ８、沸点２１８℃）、テルピネオール（Ｃ１０、沸点２１９℃）、ジヒドロテルピネオール（Ｃ１０、沸点２２０℃）、テキサノール（Ｃ１２、沸点２６０℃）、２，４－ジメチル－１，５－ペンタジオール（Ｃ９、沸点１５０℃）、及びブチルカルビトール（Ｃ８、沸点２３０℃）からなる群より選ばれる少なくとも一つを用いることができる。また、有機溶剤として、イソホロン（沸点２１５℃）、エチレングリコール（沸点１９７℃）、及びブチルカルビトールアセテート（沸点２４７℃）、２，２，４－トリメチル－１，３－ペンタンジオールジイソブチレート（Ｃ１６、沸点２８０℃）からなる群より選ばれる少なくとも一つを用いることもできる。 As the organic solvent, it is preferable to use one having a total number of carbons of 8 to 16, having a hydroxyl group, and further having a boiling point of 280 ° C. or less. Specifically, diethylene glycol monoethyl ether acetate (C8, boiling point 218 ° C.), terpineol (C10, boiling point 219 ° C.), dihydroterpineol (C10, boiling point 220 ° C.), texanol (C12, boiling point 260 ° C.) as an organic solvent At least one selected from the group consisting of 2,4-dimethyl-1,5-pentadiol (C9, boiling point 150 ° C.) and butyl carbitol (C8, boiling point 230 ° C.) can be used. In addition, as organic solvents, isophorone (boiling point 215 ° C), ethylene glycol (boiling point 197 ° C), butyl carbitol acetate (boiling point 247 ° C), 2,2,4-trimethyl-1,3-pentanediol diisobutyrate ( It is also possible to use at least one selected from the group consisting of C16, boiling point 280 ° C.).
　導電性組成物における有機溶剤の添加量は特に限定されないが、導電性組成物をスクリーン印刷法などにより塗布することが可能な粘度となるように調整することが好ましい。具体的には、導電性組成物全体に対し、有機溶剤の含有量は１０質量％～２５質量％とすることが好ましい。 Although the addition amount of the organic solvent in the conductive composition is not particularly limited, it is preferable to adjust the conductive composition so as to have a viscosity that can be applied by a screen printing method or the like. Specifically, the content of the organic solvent is preferably 10% by mass to 25% by mass with respect to the entire conductive composition.
　本実施形態の導電性組成物は、ペーストの分散安定性や焼成後の導体の性能に悪影響を与えない範囲内で、消泡剤、界面活性剤、レオロジー調整剤等の印刷特性や導体特性を改善する添加剤を含有していてもよい。 The conductive composition of the present embodiment has printing characteristics and conductor characteristics such as an antifoaming agent, a surfactant, and a rheology modifier within a range not adversely affecting the dispersion stability of the paste and the performance of the conductor after firing. It may contain additives to improve.
　本実施形態の導電性組成物において、当該導電性組成物を基材に塗布及び焼成して形成された導体の比抵抗は、５．０×１０－６Ω・ｃｍ以下であることが好ましい。導体の比抵抗をこのような値とすることにより、導体の比抵抗を銀バルクと同等にすることができる。なお、導体の比抵抗は、ＪＩＳ　Ｋ７１９４（導電性プラスチックの４探針法による抵抗率試験方法）に準じて測定することができる。具体的には、導体の比抵抗は、４探針抵抗測定器により測定することができる。 In the conductive composition of the present embodiment, the specific resistance of a conductor formed by applying and baking the conductive composition on a substrate is preferably 5.0 × 10 −6 Ω · cm or less. By setting the specific resistance of the conductor to such a value, it is possible to make the specific resistance of the conductor equal to that of silver bulk. In addition, the specific resistance of a conductor can be measured according to JIS K 7194 (The resistivity test method by the 4-probe method of electroconductive plastic). Specifically, the resistivity of the conductor can be measured by a four probe resistance measuring device.
　本実施形態の導電性組成物において、粘着力が３．９Ｎ／１０ｍｍ～３９Ｎ／１０ｍｍのテープを上記導体に圧着して剥離した際に、基材から導体が剥離しないことが好ましい。基材から導体が剥離しないとは、具体的には、テープを導体に圧着して剥離した際に、テープ側において基材から剥離した導体が目視で確認できなかった場合、又は、配線板側において導体の剥離が目視で確認できなかった場合をいう。導電性組成物を基材に塗布及び焼成して形成された導体がこのような特性を有することにより、基材に対する導体の密着性が十分であることから、配線板の小型化、薄型化、立体化等が容易になる。なお、テープの粘着力は、４．３Ｎ／１０ｍｍ以上３９Ｎ／１０ｍｍ以下であることが好ましく、５．３Ｎ／１０ｍｍ以上３８Ｎ／１０ｍｍ以下であることがより好ましい。 In the conductive composition of the present embodiment, when the tape having an adhesive strength of 3.9 N / 10 mm to 39 N / 10 mm is pressure-bonded to the conductor and peeled, it is preferable that the conductor does not peel from the substrate. Specifically, when the conductor is not peeled off from the substrate, when the tape is crimped to the conductor and peeled off, the conductor peeled off from the substrate can not be visually confirmed on the tape side, or the wiring board side In the case where the peeling of the conductor could not be confirmed visually. Since the conductor formed by applying and baking the conductive composition on a substrate has such characteristics, the adhesion of the conductor to the substrate is sufficient, so that the wiring board can be miniaturized and thinned. Three-dimensionalization etc. become easy. The adhesive strength of the tape is preferably 4.3 N / 10 mm or more and 39 N / 10 mm or less, and more preferably 5.3 N / 10 mm or more and 38 N / 10 mm or less.
　上述のように、導電性組成物は、金属ナノ粒子及び金属粒子などの金属成分、並びに熱硬化性樹脂、硬化剤及びセルロース樹脂などの樹脂成分で構成されている。そして、当該導電性組成物を基材に塗布した後に焼成することで、導体が形成される。このとき、得られる導体と基材との密着性を高めるために、導電性組成物中には、ある程度の量の樹脂成分を添加することが好ましい。 As described above, the conductive composition is composed of metal components such as metal nanoparticles and metal particles, and resin components such as a thermosetting resin, a curing agent, and a cellulose resin. And a conductor is formed by baking after apply | coating the said conductive composition to a base material. At this time, in order to enhance the adhesion between the obtained conductor and the substrate, it is preferable to add a certain amount of resin component to the conductive composition.
　ここで、はんだは、金属とは接合し易い反面、樹脂とは接合し難い特性を有する。そのため、樹脂成分により、実装時に導体とはんだとの濡れ性が低下し、フィレット形状が形成し難くなる、又は、はんだボールが形成される場合がある。そして、このような場合には、導体と実装部品との接合強度が満足しない可能性がある。 Here, while solder is easy to bond to metal, it has characteristics that it is difficult to bond to resin. Therefore, due to the resin component, the wettability between the conductor and the solder may be reduced at the time of mounting, making it difficult to form a fillet shape, or a solder ball may be formed. And in such a case, the joint strength of a conductor and mounting components may not be satisfied.
　このような観点から、導電性組成物全体に対し、熱硬化性樹脂と硬化剤の合計の含有量は、０．１質量％～６質量％であることが好ましい。上記合計の含有量が０．１質量％以上の場合、導電性組成物を焼成してなる導体と基材との密着性をより向上させることができる。上記合計の含有量が６質量％以下の場合、導体中の相対的な金属成分の含有量が増加するため、導体の導電性を向上させることができる。 From such a viewpoint, the total content of the thermosetting resin and the curing agent is preferably 0.1% by mass to 6% by mass with respect to the entire conductive composition. When the total content is 0.1% by mass or more, the adhesion between the conductor formed by firing the conductive composition and the substrate can be further improved. When the total content is 6% by mass or less, the relative metal component content in the conductor increases, so the conductivity of the conductor can be improved.
　また、導電性組成物全体に対し、熱硬化性樹脂と硬化剤の合計の含有量は、０．１質量％～５質量％であることがより好ましく、０．１質量％～４質量％であることがさらに好ましく、０．１質量％～２質量％であることが特に好ましい。熱硬化性樹脂と硬化剤の合計の含有量をこの範囲内にすることにより、得られる導体中の樹脂成分が減少するため、導体に対するはんだの濡れ性を向上させることができる。つまり、導電性組成物全体における樹脂成分を低減することにより、金属ナノ粒子と金属粒子とが接触しやすくなり、焼結が促されることから、空孔が縮小して金属濃度が高い導体を得ることができる。そして、このような導体は、基材への密着性とはんだの濡れ性という背反した特性を満足することを可能にしている。また、このような導体は、焼成後に表面に出てくるフラックスが少ないことから、良好なはんだ濡れ性を可能としている。 The total content of the thermosetting resin and the curing agent is more preferably 0.1% by mass to 5% by mass, and 0.1% by mass to 4% by mass with respect to the entire conductive composition. And more preferably 0.1% by mass to 2% by mass. By setting the total content of the thermosetting resin and the curing agent within this range, the resin component in the obtained conductor is reduced, so that the wettability of the solder to the conductor can be improved. That is, by reducing the resin component in the entire conductive composition, the metal nanoparticles and the metal particles are easily brought into contact with each other, and sintering is promoted, so that the pores are reduced to obtain a conductor having a high metal concentration. be able to. And such a conductor makes it possible to satisfy the contradictory characteristics of the adhesion to the substrate and the wettability of the solder. In addition, such a conductor enables good solder wettability because less flux comes out to the surface after firing.
　以上のように、本実施形態の導電性組成物は、３０ｎｍ～６００ｎｍの平均粒子径を有する金属ナノ粒子と、金属ナノ粒子より大きい平均粒子径を有する金属粒子と、分子内にオキシラン環を有する熱硬化性樹脂と、硬化剤と、セルロース樹脂と、を含有する。そして、導電性組成物を基材に塗布及び焼成して形成された導体の比抵抗が５．０×１０－６Ω・ｃｍ以下であり、かつ、粘着力が３．９Ｎ／１０ｍｍ～３９Ｎ／１０ｍｍのテープを導体に圧着して剥離した際に基材から導体が剥離しない。そのため、銀バルクと同等の比抵抗であり、基材への密着性が良好である導体を得ることができる。したがって、自動車用の配線板に適用することが可能となる。 As described above, the conductive composition of the present embodiment has metal nanoparticles having an average particle size of 30 nm to 600 nm, metal particles having an average particle size larger than the metal nanoparticles, and an oxirane ring in the molecule. It contains a thermosetting resin, a curing agent, and a cellulose resin. And the specific resistance of the conductor formed by apply | coating and baking an electroconductive composition to a base material is 5.0 * 10 < -6 > ohm * cm or less, and the adhesive force is 3.9 N / 10 mm-39 N / When the 10 mm tape is crimped to the conductor and peeled off, the conductor does not peel off from the substrate. Therefore, it is possible to obtain a conductor having a specific resistance equivalent to that of silver bulk and good adhesion to a substrate. Therefore, it becomes possible to apply to the wiring board for cars.
　また、本実施形態の導電性組成物を焼成してなる導体は、はんだ濡れ性が良好である。そのため、はんだを用いて導体に部品を実装した場合、十分な実装強度を得ることができる。 Moreover, the conductor formed by firing the conductive composition of the present embodiment has good solder wettability. Therefore, when a component is mounted on a conductor using solder, sufficient mounting strength can be obtained.
［配線板］
　本実施形態に係る配線板は、上述の導電性組成物より得られる導体を備えている。上述のように、本実施形態の導電性組成物より得られる導体は、比抵抗が５．０×１０－６Ω・ｃｍ以下であり、かつ、粘着力が３．９Ｎ／１０ｍｍ～３９Ｎ／１０ｍｍのテープで良好な密着性を示す。上記配線板は、長期間の使用にも耐えうる密着性を有し、導体を流れる電流量を高めることができるため、自動車用として好適に用いることができる。 [Wiring board]
The wiring board according to the present embodiment includes a conductor obtained from the above-described conductive composition. As described above, the conductor obtained from the conductive composition of the present embodiment has a specific resistance of 5.0 × 10 −6 Ω · cm or less and an adhesive strength of 3.9 N / 10 mm to 39 N / 10 mm. The tape shows good adhesion. The above-mentioned wiring board has adhesiveness which can endure long-term use, and since it can raise the amount of current which flows through a conductor, it can be used suitably for cars.
　本実施形態の配線板は、基材上に導電性組成物を所望の形状に塗布した後、焼成することにより得ることができる。配線板に用いることができる基材は特に限定されず、電気絶縁性のフィルム又は板材を用いることができる。このような基材は屈曲性があり、使用箇所に応じて折り曲げなどに対応することができる。基材の材料は特に限定されず、例えばポリイミド（ＰＩ）、ポリエチレンテレフタラート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリカーボネート（ＰＣ）、ポリプロピレン（ＰＰ）、ポリブチレンテレフタレート（ＰＢＴ）からなる群より選ばれる少なくとも一つを用いることができる。 The wiring board of the present embodiment can be obtained by applying a conductive composition on a base material in a desired shape and then baking it. The base material that can be used for the wiring board is not particularly limited, and an electrically insulating film or plate can be used. Such a base material is flexible and can cope with bending or the like according to the place of use. The material of the substrate is not particularly limited. For example, from the group consisting of polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (PP), polybutylene terephthalate (PBT) At least one selected can be used.
　導電性組成物を基材上に塗布する方法は特に限定されず、フレキソ印刷、グラビア印刷、グラビアオフセット印刷、オフセット印刷、スクリーン印刷、ロータリースクリーン印刷等、従来公知の方法により行うことができる。 The method for applying the conductive composition on a substrate is not particularly limited, and the method can be performed by a conventionally known method such as flexographic printing, gravure printing, gravure offset printing, offset printing, screen printing, rotary screen printing, and the like.
　導電性組成物を基材上に塗布した後の焼成方法も特に限定されない。例えば、導電性組成物を塗布した基材を１４０℃以上の熱風に晒すことが好ましい。これにより、導電性組成物中の有機溶剤などが除去され、金属ナノ粒子及び金属粒子が焼結するため、高導電性の導体を得ることができる。なお、導電性組成物を塗布した基材を２５０℃以上の熱風に晒すことがより好ましい。焼成温度を上げることにより、得られる焼結体がより緻密になるため、更なる低抵抗化を図ることが可能となる。なお、焼成方法は上述の熱風焼成に限定されず、例えばプラズマ焼成、光焼成、パルス波焼成も適用することができる。 The baking method after apply | coating a conductive composition on a base material is not specifically limited, either. For example, the substrate coated with the conductive composition is preferably exposed to hot air of 140 ° C. or higher. Thereby, the organic solvent etc. in a conductive composition are removed, and since a metal nanoparticle and metal particles sinter, a highly conductive conductor can be obtained. In addition, it is more preferable to expose the base material which apply | coated the conductive composition to the hot air 250 degreeC or more. By raising the firing temperature, the resulting sintered body becomes more compact, so that it is possible to further reduce the resistance. In addition, the baking method is not limited to the above-mentioned hot-air baking, For example, plasma baking, light baking, pulse wave baking can also be applied.
　導電性組成物より得られる導体を備えた配線板は、導体の表面を覆って保護するための絶縁カバー材を備えていてもよい。絶縁カバー材としては、絶縁フィルムやレジストを用いることができる。絶縁カバー材は、粘着剤を片面に有するポリエチレンテレフタラート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリカーボネート（ＰＣ）、ポリプロピレン（ＰＰ）、ポリブチレンテレフタレート（ＰＢＴ）、ポリウレタン（ＰＵ）等を用いることが好ましい。また、レジストは、熱硬化性レジスト、ＵＶ硬化性レジストを用いることが好ましく、特にエポキシ系レジスト、ウレタン系レジストを用いることが好ましい。 The wiring board provided with the conductor obtained from the conductive composition may be provided with an insulating cover material for covering and protecting the surface of the conductor. An insulating film or a resist can be used as the insulating cover material. Use polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (PP), polybutylene terephthalate (PBT), polyurethane (PU), etc. that have an adhesive on one side as the insulating cover material Is preferred. The resist is preferably a thermosetting resist or a UV curable resist, and particularly preferably an epoxy resist or a urethane resist.
　以下、本実施形態を実施例及び比較例によりさらに詳細に説明するが、本実施形態はこれら実施例に限定されるものではない。 Hereinafter, the present embodiment will be described in more detail by way of examples and comparative examples, but the present embodiment is not limited to these examples.
［導電性組成物の調製］
　まず、金属ナノ粒子、金属粒子、熱硬化性樹脂、硬化剤、樹脂及び有機溶剤を、自転公転攪拌機を用い、表１～表５に示す配合比で攪拌することにより、各例の導電性組成物を調製した。各例の導電性組成物の原料として用いた材料は以下の通りである。 [Preparation of conductive composition]
First, the conductive composition of each example is obtained by stirring metal nanoparticles, metal particles, thermosetting resin, curing agent, resin and organic solvent using the rotation and revolution stirrer at the compounding ratio shown in Tables 1 to 5. Prepared. The materials used as the raw material of the conductive composition of each example are as follows.
　（金属ナノ粒子）
　平均粒子径がそれぞれ２５ｎｍ、３０ｎｍ、７０ｎｍ、３５０ｎｍ、６００ｎｍ、７００ｎｍである銀ナノ粒子 (Metal nanoparticles)
Silver nanoparticles having an average particle size of 25 nm, 30 nm, 70 nm, 350 nm, 600 nm and 700 nm, respectively
　（金属粒子）
　平均粒子径がそれぞれ１．０μｍ、３．０μｍ、５．０μｍ、６．０μｍである銀粒子 (Metal particles)
Silver particles having an average particle size of 1.0 μm, 3.0 μm, 5.0 μm and 6.0 μm, respectively
　（熱硬化性樹脂）
・ビスフェノールＡ型エポキシ樹脂　三菱ケミカル株式会社製、ｊＥＲ（登録商標）８２８
・ビスフェノールＦ型エポキシ樹脂　ＤＩＣ株式会社製、ＥＰＩＣＬＯＮ（登録商標）８３０
・脂肪族型エポキシ樹脂　新日鉄住金化学株式会社製、ＰＧ－２０７ＧＳ（ポリプロピレングリコールジグリシジルエーテル）
・ノボラック型エポキシ樹脂　新日鉄住金化学株式会社製、ＹＤＰＮ－６３８（フェノールノボラック型エポキシ樹脂）
・フェノール樹脂　群栄化学工業株式会社製、ＰＳ―２６０８
・ウレタン樹脂　荒川化学工業株式会社製、ユリアーノ（登録商標）ＫＬ－４２２ (Thermosetting resin)
-Bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation, jER (registered trademark) 828
-Bisphenol F type epoxy resin DIC Corporation EPICLON (registered trademark) 830
-Aliphatic epoxy resin, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., PG-207GS (polypropylene glycol diglycidyl ether)
・ Novolak type epoxy resin Made by Nippon Steel & Sumikin Chemical Co., Ltd., YDPN-638 (phenol novolac type epoxy resin)
・ Phenolic resin Gunei Chemical Industry Co., Ltd. PS-2608
Urethane resin Arakawa Chemical Industries, Ltd., Uuliano (registered trademark) KL-422
　（硬化剤）
・ジシアンジアミド　三菱ケミカル株式会社製、ＤＩＣＹ７
・イミダゾール　日本曹達株式会社製、ＮＩＳＳＯＣＵＲＥ（登録商標）　ＴＩＣ－１８８
・ヘキサメチレンテトラミン　三菱ガス化学株式会社製
・ポリイソシアネート　ＤＩＣ株式会社製、ＢＵＲＮＯＣＫ（登録商標）　Ｄ－７５０ (Hardening agent)
-Dicyandiamide Mitsubishi Chemical Corporation, DICY7
-Imidazole Nippon Soda Co., Ltd. make, NISSOCURE (registered trademark) TIC-188
Hexamethylenetetramine Mitsubishi Gas Chemical Co. Polyisocyanate DIC Co., Ltd., BURNOCK (registered trademark) D-750
　（樹脂成分）
・ヒドロキシエチルメチルセルロース　信越化学工業株式会社製、メトローズ（登録商標）ＳＥＢ０４Ｔ
・エチルセルロース　ダウ・ケミカル・カンパニー製、エトセル（登録商標）ＳＴＤ４
・エチルセルロースアクリルポリマー　大成ファインケミカル株式会社製、アクリット（登録商標）ＫＷＥ－２５０Ｔ
・ポリアミド　東京インキ株式会社製、Ｆ－９１５
・アクリル樹脂　ＤＩＣ株式会社製、ＡＣＲＹＤＩＣ（登録商標）５２－２０４ (Resin component)
Hydroxyethyl methyl cellulose, manufactured by Shin-Etsu Chemical Co., Ltd., Metrose (registered trademark) SEB 04 T
・ Ethyl cellulose Dow Chemical Company, Ethocel (registered trademark) STD 4
-Ethyl cellulose acrylic polymer manufactured by Taisei Fine Chemical Co., Ltd., Akrit (registered trademark) KWE-250T
・ Polyamide made by Tokyo Ink Co., Ltd., F-915
-Acrylic resin DIC Corporation ACRYDIC (registered trademark) 52-204
　（有機溶剤）
・テルピネオール　東京化成工業株式会社製
・ジエチレングリコールモノエチルエーテルアセテート　東京化成工業株式会社製
・テキサノール（2,2,4-トリメチルペンタン-1,3-ジオールモノイソブチラート）　イーストマンケミカル社製 (Organic solvent)
Terpineol Tokyo Chemical Industry Co., Ltd. Diethylene glycol monoethyl ether acetate Tokyo Chemical Industry Co. Texanol (2,2,4-trimethylpentane-1,3-diol monoisobutyrate) Eastman Chemical Co.
［評価］
　各例の導電性組成物について、以下のように評価をした。これらの結果を表１～表５にそれぞれ示す。 [Evaluation]
The conductive compositions of each example were evaluated as follows. The results are shown in Tables 1 to 5, respectively.
　（導体の比抵抗）
　導体の比抵抗は、ＪＩＳ　Ｋ７１９４を参考に測定を行った。装置は、４探針抵抗測定器（エヌピイエス株式会社製抵抗率測定器Sigma-5+）を用いた。 (Specific resistance of conductor)
The specific resistance of the conductor was measured with reference to JIS K 7194. As a device, a four-point probe resistance measurement device (a resistivity measurement device Sigma-5 + manufactured by NPP Inc.) was used.
　具体的には、まず、焼成後に幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を印刷した。次に、回路を印刷したポリイミドフィルムを３０分間室温で放置した後、１４０℃で３０分間、熱風で焼成することにより、配線板を作製した。 Specifically, first, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so as to be 1 mm wide by 10 cm thick and 30 μm wide after firing. Next, the circuit board-printed polyimide film was allowed to stand at room temperature for 30 minutes and then fired at 140 ° C. for 30 minutes with hot air to produce a wiring board.
　次に、得られた配線板上のＡｇ薄膜に対し、両端から各１ｃｍの部分と中心の５ｃｍの部分の３点で表面抵抗を測定した。なお、表面抵抗は、針を回路に対して平行に置いた状態で測定を行った。 Next, with respect to the obtained Ag thin film on the wiring board, the surface resistance was measured at three points of 1 cm from each end and 5 cm at the center. The surface resistance was measured with the needle placed parallel to the circuit.
　（密着性１）
　ポリイミドフィルムに対する導電性組成物の密着性は、粘着力が３．９Ｎ／１０ｍｍ～５．７Ｎ／１０ｍｍのテープを用いた剥離試験により評価した。 (Adhesion 1)
The adhesion of the conductive composition to the polyimide film was evaluated by a peeling test using a tape having an adhesive strength of 3.9 N / 10 mm to 5.7 N / 10 mm.
　具体的には、まず、焼成後に幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を印刷した。回路を印刷したポリイミドフィルムを３０分間室温で放置した後、１４０℃で３０分間、熱風で焼成することにより、配線板を作製した。 Specifically, first, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so as to be 1 mm wide by 10 cm thick and 30 μm wide after firing. The circuit board-printed circuit board was fabricated by allowing the polyimide film printed with the circuit to stand for 30 minutes at room temperature and then firing at 140 ° C. for 30 minutes with hot air.
　次に、得られた配線板に対し、テープの接着面を気泡が残らないように指で圧着し、約１０秒経過後、印刷面に直角の方向に、素早くテープを引きはがした。なお、テープは、粘着力が５．３０Ｎ／１０ｍｍのニチバン株式会社製アルミテープ　Ｎｏ．９５０を用いた。
・判定基準
　○：印刷剥離が見られない（テープ側において剥離した回路が確認できない場合、及び、配線板側において回路の剥離が目視で確認できない場合）
　×：印刷剥離が見られる（テープ側において剥離した回路が確認できた場合、又は、配線板側において回路の剥離が目視で確認できた場合） Next, the adhesive surface of the tape was pressure-bonded to the obtained wiring board with a finger so as not to leave air bubbles, and after about 10 seconds, the tape was quickly peeled off in the direction perpendicular to the printing surface. The tape used is an aluminum tape No. 5 manufactured by Nichiban Co., Ltd. with an adhesive strength of 5.30 N / 10 mm. 950 was used.
Judgment criteria :: No peeling off of printing observed (when the peeled circuit can not be confirmed on the tape side, and when peeling of the circuit can not be visually confirmed on the wiring board side)
X: Peeling of printing is observed (when the peeled circuit can be confirmed on the tape side, or the peeling of the circuit can be visually confirmed on the wiring board side)
　（かすれ）
　印刷のかすれは、次のようにして評価した。まず、焼成後の大きさが幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を印刷した。次に、回路を印刷したポリイミドフィルムを３０分間室温で放置した後、１４０℃で３０分間、熱風で焼成することにより、配線板を作製した。そして、得られた配線板において、回路の印刷にかすれがないか、目視にて評価した。
・判定基準
　○：かすれなし
　×：かすれあり (Slightly)
The blur of the printing was evaluated as follows. First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that the size after firing was 1 mm in width, 10 cm in length, and 30 μm in thickness. Next, the circuit board-printed polyimide film was allowed to stand at room temperature for 30 minutes and then fired at 140 ° C. for 30 minutes with hot air to produce a wiring board. Then, in the obtained wiring board, it was visually evaluated whether or not the printing of the circuit was blurred.
· Judgment criteria ○: No blur ×: There is blur
　（にじみ）
　印刷のにじみは、次のようにして評価した。まず、焼成後の大きさが幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を印刷した。次に、回路を印刷したポリイミドフィルムを１０分間室温で放置した後、印刷の境界部ににじみがあるかどうかをマイクロスコープで確認し、にじみを評価した。
・判定基準
　○：にじみなし
　×：にじみあり (Bread)
The bleeding of the printing was evaluated as follows. First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that the size after firing was 1 mm in width, 10 cm in length, and 30 μm in thickness. Next, the circuit-printed polyimide film was allowed to stand at room temperature for 10 minutes, and then it was checked with a microscope to see if there is any bleeding at the printing boundary, and the bleeding was evaluated.
· Judgment criteria ○: Niji Minashi ×: There is bleeding
　（ダレ）
　印刷のダレは、次のようにして評価した。まず、焼成後の大きさが幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を印刷した。次に、回路を印刷したポリイミドフィルムを１０分間室温で放置した後、印刷部がスクリーンマスクで設計した転写形状と同等か否かをマイクロスコープで確認し、ダレを評価した。
・判定基準
　○：ダレあり
　×：ダレなし (Dare)
The dripping of the print was evaluated as follows. First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that the size after firing was 1 mm in width, 10 cm in length, and 30 μm in thickness. Next, after allowing the polyimide film printed with the circuit to stand at room temperature for 10 minutes, it was confirmed with a microscope whether the printed part was equivalent to the transfer shape designed by the screen mask, and the sag was evaluated.
· Judgment criteria ○: With dripping ×: Without dripping
　（メッシュ痕）
　印刷のメッシュ痕は、次のようにして評価した。まず、焼成後の大きさが幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を印刷した。次に、回路を印刷したポリイミドフィルムを１０分間室温で放置した後、印刷部の表面にメッシュ痕があるか否かをマイクロスコープで確認し、メッシュ痕を評価した。
・判定基準
　○：メッシュ痕なし
　×：メッシュ痕あり (Mesh mark)
The mesh marks on the print were evaluated as follows. First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that the size after firing was 1 mm in width, 10 cm in length, and 30 μm in thickness. Next, the circuit-printed polyimide film was allowed to stand at room temperature for 10 minutes, and then whether or not there was a mesh mark on the surface of the printed portion was confirmed with a microscope to evaluate the mesh mark.
· Judgment criteria ○: no mesh marks ×: mesh marks
　（貼り付き性）
　印刷時のスキージ貼り付き性は、次のように評価した。まず、焼成後の大きさが幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を３枚印刷した。印刷後にスキージを上げ、スキージに導電性組成物の付着の様子を評価した。
・判定基準
　◎：スキージにまとまった導電性組成物の付着がない場合
　○：スキージにまとまった導電性組成物の付着があるが５秒以内に落ちる場合
　×：スキージにまとまった導電性組成物の付着があり全く落ちてこない場合 (Stickability)
The squeegee stickiness at the time of printing was evaluated as follows. First, using a screen printer, three circuits were printed with the conductive composition obtained in each example on a polyimide film so that the size after firing was 1 mm in width, 10 cm in length, and 30 μm in thickness. After printing, the squeegee was raised and the appearance of the adhesion of the conductive composition to the squeegee was evaluated.
· Evaluation criteria :: no adhesion of the conductive composition collected on the squeegee ○: adhesion of the conductive composition collected on the squeegee but it falls within 5 seconds ×: the conductive composition collected on the squeegee When there is adhesion and it does not fall at all
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
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　表１及び表２に示すように、実施例１－１～実施例１－１０の導電性組成物により形成された配線板では、導体の比抵抗が小さく、基材に対する導体の密着性も良好である。一方、表３～表５に示すように、比較例１－１～比較例１－１３の導電性組成物により形成された配線板では、導体の比抵抗が大きいか、又は、基材に対する導体の密着性が良好ではなかった。 As shown in Tables 1 and 2, in the wiring boards formed of the conductive compositions of Examples 1-1 to 1-10, the specific resistance of the conductor is small, and the adhesion of the conductor to the substrate is also good. It is. On the other hand, as shown in Tables 3 to 5, in the wiring board formed of the conductive composition of Comparative Example 1-1 to Comparative Example 1-13, the specific resistance of the conductor is large or the conductor relative to the base material The adhesion of was not good.
［導電性組成物の調製］
　まず、金属ナノ粒子、金属粒子、熱硬化性樹脂、硬化剤、樹脂及び有機溶剤を、自転公転攪拌機を用い、表６～表１０に示す配合比で攪拌することにより、各例の導電性組成物を調製した。各例の導電性組成物の原料として用いた材料は、実施例１と同じものを使用した。なお、比較例２－２，２－４～２－６及び２－８～２－１３の導電性組成物は、それぞれ比較例１－２，１－４～１－６及び１－８～１－１３の導電性組成物と組成が同じである。 [Preparation of conductive composition]
First, the conductive composition of each example is obtained by stirring metal nanoparticles, metal particles, thermosetting resin, curing agent, resin and organic solvent using the rotation and revolution stirrer at the compounding ratio shown in Tables 6 to 10. Prepared. The same material as that of Example 1 was used as the material of the conductive composition of each example. Note that the conductive compositions of Comparative Examples 2-2, 2-4 to 2-6 and 2-8 to 2-13, respectively, are Comparative Examples 1-2, 1-4 to 1-6 and 1-8 to 1, respectively. The composition is the same as the conductive composition of -13.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
［評価］
　各例の導電性組成物について、実施例１と同じように、「導体の比抵抗」、「密着性１」、「かすれ」、「にじみ」、「ダレ」、「メッシュ痕」、及び「貼り付き性」の評価を行った。さらに、各例の導電性組成物について、次の評価も行った。これらの結果を表６～表１０にそれぞれ示す。 [Evaluation]
About the conductive composition of each example, as in Example 1, “specific resistance of conductor”, “adhesion 1”, “scrub”, “blur”, “shrink”, “mesh scar”, and “paste” The evaluation of "stickiness" was performed. Furthermore, the following evaluation was also performed about the conductive composition of each case. The results are shown in Tables 6 to 10, respectively.
　（密着性２）
　まず、焼成後に幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を印刷した。回路を印刷したポリイミドフィルムを３０分間室温で放置した後、１４０℃で３０分間、熱風で焼成することにより、配線板を作製した。 (Adhesion 2)
First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that after firing, the width was 1 mm, length 10 cm, thickness 30 μm. The circuit board-printed circuit board was fabricated by allowing the polyimide film printed with the circuit to stand for 30 minutes at room temperature and then firing at 140 ° C. for 30 minutes with hot air.
　次に、得られた配線板に対し、テープの接着面を気泡が残らないように指で圧着し、約１０秒経過後、印刷面に直角の方向に、素早くテープを引きはがした。なお、テープは、粘着力が３８Ｎ／１０ｍｍの３Ｍ社製ＶＨＢ超強力両面テープ　低ＶＯＣタイプ　製品番号Y-4825K-08を用いた。
・判定基準
　○：印刷剥離が見られない（テープ側において剥離した回路が確認できない場合、及び、配線板側において回路の剥離が目視で確認できない場合）
　×：印刷剥離が見られる（テープ側において剥離した回路が確認できた場合、又は、配線板側において回路の剥離が目視で確認できた場合） Next, the adhesive surface of the tape was pressure-bonded to the obtained wiring board with a finger so as not to leave air bubbles, and after about 10 seconds, the tape was quickly peeled off in the direction perpendicular to the printing surface. The tape used was a 3M manufactured VHB super-strong double-sided tape with an adhesive strength of 38 N / 10 mm and a low VOC type, product number Y-4825 K-08.
Judgment criteria :: No peeling off of printing observed (when the peeled circuit can not be confirmed on the tape side, and when peeling of the circuit can not be visually confirmed on the wiring board side)
X: Peeling of printing is observed (when the peeled circuit can be confirmed on the tape side, or the peeling of the circuit can be visually confirmed on the wiring board side)
　（はんだ濡れ性）
　まず、焼成後に幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を印刷した。次に、回路を印刷したポリイミドフィルムを３０分間室温で放置した後、１４０℃で３０分間、熱風で焼成することにより、配線板を作製した。 (Solder wettability)
First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that after firing, the width was 1 mm, length 10 cm, thickness 30 μm. Next, the circuit board-printed polyimide film was allowed to stand at room temperature for 30 minutes and then fired at 140 ° C. for 30 minutes with hot air to produce a wiring board.
　次に、得られた配線板上のＡｇ薄膜に対し、Ｓｎ－Ｂｉ系低温はんだを垂らして加熱した後、はんだ濡れ性を評価した。具体的には、Ａｇ薄膜上のはんだの接触角を、接触角計を用いてθ／２法で測定した。接触角計は、協和界面科学株式会社製CONTACT-ANGLE METER FACE TYPE01を用いた。
・判定基準
　○：接触角θ＜９０°
　×：接触角θ≧９０° Next, Sn-Bi-based low temperature solder was dropped on the obtained Ag thin film on the wiring board and heated, and then the solder wettability was evaluated. Specifically, the contact angle of the solder on the Ag thin film was measured by the θ / 2 method using a contact angle meter. As the contact angle meter, CONTACT-ANGLE METER FACE TYPE 01 manufactured by Kyowa Interface Science Co., Ltd. was used.
· Judgment criteria ○: Contact angle θ <90 °
×: contact angle θ ≧ 90 °
　（実装強度）
　まず、焼成後に幅１ｍｍ長さ１０ｃｍ厚さ３０μｍとなるように、ポリイミドフィルム上に、スクリーン印刷機を用い、各例で得られた導電性組成物で回路を印刷した。次に、回路を印刷したポリイミドフィルムを３０分間室温で放置した後、１４０℃で３０分間、熱風で焼成することにより、配線板を作製した。 (Mounting strength)
First, a circuit was printed with a conductive composition obtained in each example on a polyimide film using a screen printer so that after firing, the width was 1 mm, length 10 cm, thickness 30 μm. Next, the circuit board-printed polyimide film was allowed to stand at room temperature for 30 minutes and then fired at 140 ° C. for 30 minutes with hot air to produce a wiring board.
　次に、得られた配線板上のＡｇ薄膜に対し、Ｓｎ－Ｂｉ系低温はんだを用いて、３２１６サイズの０Ω抵抗器をはんだ付けした。そして、得られた回路のシェア強度を、ボンドテスター（Nordson Dage社製、SERIES4000）を用いて測定した。
・判定基準
　◎：シェア強度が５０Ｎ以上
　○：シェア強度が２０Ｎ以上５０Ｎ未満
　×：シェア強度が２０Ｎ未満
　－：シェア強度が測定不能 Next, a 3216 size 0 Ω resistor was soldered to the obtained Ag thin film on the wiring board using Sn—Bi based low temperature solder. And the shear strength of the obtained circuit was measured using a bond tester (manufactured by Nordson Dage, SERIES 4000).
· Judgment criteria ◎: The share strength is 50N or more ○: The share strength is 20N or more and less than 50N ×: The share strength is less than 20N-: The share strength can not be measured
　表６及び表７に示すように、実施例２－１～実施例２－１０の導電性組成物により形成された配線板では、導体の比抵抗が小さく、基材に対する導体の密着性も良好であった。また、これらの実施例の導体は、はんだ濡れ性及び実装強度の評価も良好であり、実装性に優れることが分かる。 As shown in Tables 6 and 7, in the wiring boards formed of the conductive compositions of Examples 2-1 to 2-10, the specific resistance of the conductor is small, and the adhesion of the conductor to the substrate is also good. Met. In addition, it is understood that the conductors of these examples are also good in the evaluation of the solder wettability and the mounting strength, and are excellent in the mounting property.
　一方、表８～表１０に示すように、比較例２－１～比較例２－１３の導電性組成物により形成された配線板では、導体の比抵抗が大きいか、基材に対する導体の密着性が良好ではなかった。特に、比較例２－１及び２－３の導電性組成物は樹脂成分が多いことから、これらにより形成された導体は、はんだ濡れ性及び実装強度が不十分であり、実装性に劣ることが分かる。 On the other hand, as shown in Table 8 to Table 10, in the wiring board formed of the conductive composition of Comparative Example 2-1 to Comparative Example 2-13, it is determined whether the specific resistance of the conductor is large or the adhesion of the conductor to the base material The sex was not good. In particular, since the conductive compositions of Comparative Examples 2-1 and 2-3 have a large amount of resin components, the conductors formed therefrom have insufficient solder wettability and mounting strength and are inferior in mountability. I understand.
　以上、本発明を実施例によって説明したが、本発明はこれらに限定されるものではなく、本発明の要旨の範囲内で種々の変形が可能である。 As mentioned above, although the present invention was explained by the example, the present invention is not limited to these and various modification is possible within the scope of the present invention.
　特願２０１７－１７９９６１号（出願日：２０１７年９月２０日）及び特願２０１８－１１４３７７号（出願日：２０１８年６月１５日）の全内容は、ここに援用される。 The entire contents of Japanese Patent Application No. 2017-179961 (filing date: September 20, 2017) and Japanese Patent Application No. 2018-114377 (filing date: June 15, 2018) are incorporated herein by reference.
　本発明によれば、銀バルクと同等の比抵抗であり、基材への密着性が良好である導体を得ることが可能な導電性組成物及び当該導電性組成物を用いた配線板を提供することができる。 According to the present invention, there is provided a conductive composition capable of obtaining a conductor having the same specific resistance as silver bulk and good adhesion to a substrate and a wiring board using the conductive composition. can do.

Claims (10)

  1. 　３０ｎｍ～６００ｎｍの平均粒子径を有する金属ナノ粒子と、
    　前記金属ナノ粒子より大きい平均粒子径を有する金属粒子と、
    　分子内にオキシラン環を有する熱硬化性樹脂と、
    　硬化剤と、
    　セルロース樹脂と、
    　を含有する導電性組成物であって、
    　前記導電性組成物を基材に塗布及び焼成して形成された導体の比抵抗が５．０×１０－６Ω・ｃｍ以下であり、かつ、粘着力が３．９Ｎ／１０ｍｍ～３９Ｎ／１０ｍｍのテープを前記導体に圧着して剥離した際に前記基材から前記導体が剥離しない、導電性組成物。     Metal nanoparticles having an average particle size of 30 nm to 600 nm,
    Metal particles having an average particle size larger than the metal nanoparticles;
    A thermosetting resin having an oxirane ring in the molecule,
    A curing agent,
    Cellulose resin,
    A conductive composition containing
    The specific resistance of the conductor formed by applying and baking the conductive composition to a substrate is 5.0 × 10 −6 Ω · cm or less, and the adhesive strength is 3.9 N / 10 mm to 39 N / 10 mm The conductive composition in which the said conductor does not peel from the said base material, when the tape of 4 is crimped | bonded to the said conductor and it peels.
  2. 　前記熱硬化性樹脂は、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ノボラック型エポキシ樹脂、グリシジルアミン型エポキシ樹脂及び脂肪族型エポキシ樹脂からなる群より選択される少なくとも一種である、請求項１に記載の導電性組成物。 The thermosetting resin is at least one selected from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, glycidyl amine epoxy resin, and aliphatic epoxy resin. The electroconductive composition as described in-.
  3. 　前記硬化剤は、窒素を含む五員複素環式芳香族化合物である、請求項１又は２に記載の導電性組成物。 The conductive composition according to claim 1, wherein the curing agent is a five-membered heterocyclic aromatic compound containing nitrogen.
  4. 　前記熱硬化性樹脂と前記硬化剤の含有量の比は、質量比で１：１～４：１である、請求項１～３のいずれか一項に記載の導電性組成物。 The conductive composition according to any one of claims 1 to 3, wherein a ratio of the content of the thermosetting resin to the content of the curing agent is 1: 1 to 4: 1 in mass ratio.
  5. 　導電性組成物全体に対し、前記セルロース樹脂の含有量は０．１質量％～４質量％である、請求項１～４のいずれか一項に記載の導電性組成物。 The conductive composition according to any one of claims 1 to 4, wherein the content of the cellulose resin is 0.1% by mass to 4% by mass with respect to the entire conductive composition.
  6. 　導電性組成物全体に対し、前記熱硬化性樹脂と前記硬化剤の合計の含有量は０．１質量％～６質量％である、請求項１～５のいずれか一項に記載の導電性組成物。 The conductivity according to any one of claims 1 to 5, wherein the total content of the thermosetting resin and the curing agent is 0.1% by mass to 6% by mass with respect to the entire conductive composition. Composition.
  7. 　導電性組成物全体に対し、前記熱硬化性樹脂と前記硬化剤の合計の含有量は０．１質量％～５質量％である、請求項１～６のいずれか一項に記載の導電性組成物。 The conductivity according to any one of claims 1 to 6, wherein the total content of the thermosetting resin and the curing agent is 0.1% by mass to 5% by mass with respect to the whole of the conductive composition. Composition.
  8. 　導電性組成物全体に対し、前記熱硬化性樹脂と前記硬化剤の合計の含有量は０．１質量％～２質量％である、請求項１～７のいずれか一項に記載の導電性組成物。 The conductivity according to any one of claims 1 to 7, wherein a total content of the thermosetting resin and the curing agent is 0.1% by mass to 2% by mass with respect to the entire conductive composition. Composition.
  9. 　前記金属粒子の平均粒子径が１μｍ～５μｍである、請求項１～８のいずれか一項に記載の導電性組成物。 The conductive composition according to any one of claims 1 to 8, wherein an average particle size of the metal particles is 1 μm to 5 μm.
  10. 　請求項１～９のいずれか一項に記載の導電性組成物より得られる導体を備える配線板。 A wiring board comprising a conductor obtained from the conductive composition according to any one of claims 1 to 9.
PCT/JP2018/026814 2017-09-20 2018-07-18 Conductive composition and wiring board using same WO2019058727A1 (en)

Priority Applications (3)

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DE112018005323.7T DE112018005323T5 (en) 2017-09-20 2018-07-18 CONDUCTIVE COMPOSITION AND THIS USING BOARD
CN201880055001.2A CN111065684A (en) 2017-09-20 2018-07-18 Conductive composition and wiring board using the same
US16/800,613 US11479686B2 (en) 2017-09-20 2020-02-25 Conductive composition and wiring board using the same

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JP2017179961 2017-09-20
JP2017-179961 2017-09-20
JP2018114377A JP7156831B2 (en) 2017-09-20 2018-06-15 Conductive composition and wiring board using the same
JP2018-114377 2018-06-15

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JP2011076866A (en) * 2009-09-30 2011-04-14 Mitsuboshi Belting Ltd Laminate, conductive base material using this laminate, and its manufacturing method
JP2011238596A (en) * 2010-04-14 2011-11-24 Dowa Holdings Co Ltd Thermosetting conductive paste and wiring board
JP2012084440A (en) * 2010-10-13 2012-04-26 Namics Corp Heat curable conductive paste
JP2013069654A (en) * 2011-09-21 2013-04-18 Samsung Electro-Mechanics Co Ltd Conductive paste composition for low temperature firing
JP2013149596A (en) * 2011-12-21 2013-08-01 Shoei Chem Ind Co Heat-curable conductive paste
JP2016502752A (en) * 2012-10-31 2016-01-28 ドンジン セミケム カンパニー リミテッド Copper paste composition for printed electronics
JP2016192392A (en) * 2015-03-30 2016-11-10 東洋インキＳｃホールディングス株式会社 Conductive paste for laser processing
WO2018055848A1 (en) * 2016-09-21 2018-03-29 矢崎総業株式会社 Electrically conductive paste, and wiring board using same

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011076866A (en) * 2009-09-30 2011-04-14 Mitsuboshi Belting Ltd Laminate, conductive base material using this laminate, and its manufacturing method
JP2011238596A (en) * 2010-04-14 2011-11-24 Dowa Holdings Co Ltd Thermosetting conductive paste and wiring board
JP2012084440A (en) * 2010-10-13 2012-04-26 Namics Corp Heat curable conductive paste
JP2013069654A (en) * 2011-09-21 2013-04-18 Samsung Electro-Mechanics Co Ltd Conductive paste composition for low temperature firing
JP2013149596A (en) * 2011-12-21 2013-08-01 Shoei Chem Ind Co Heat-curable conductive paste
JP2016502752A (en) * 2012-10-31 2016-01-28 ドンジン セミケム カンパニー リミテッド Copper paste composition for printed electronics
JP2016192392A (en) * 2015-03-30 2016-11-10 東洋インキＳｃホールディングス株式会社 Conductive paste for laser processing
WO2018055848A1 (en) * 2016-09-21 2018-03-29 矢崎総業株式会社 Electrically conductive paste, and wiring board using same

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