KR101950516B1 - Particle for insulation coating, insulating coated conductive particle, anisotropic conductive material, and connecting structure - Google Patents

Abstract

The present invention relates to an insulating coating particle for forming insulating coated conductive particles by coating base particles containing a metal having conductivity on a surface and comprising a core shell structure having core particles and a shell layer, and it includes, to a insulating coating particles comprising a silicone compound having a unit of at least one syelcheung the SiO _{4 /} selected from the _second unit, RSiO _3/2 units, and R ₂ a group consisting of SiO _2/2 units . R represents at least one member selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group and a? - (meth) acryloxypropyl group.

Description

TECHNICAL FIELD [0001] The present invention relates to an insulating coating particle, an insulating coating particle, an anisotropic conductive material, and an insulating coating particle, an insulating coated conductive particle, an anisotropic conductive material,

The present invention relates to insulating coating particles, insulating coated conductive particles, anisotropic conductive materials and connection structures.

It is known that it is possible to impart the base particles with heat resistance, abrasion resistance, insulating property, conductivity, water repellency, adhesiveness, dispersibility, gloss and coloration by coating a part of the surface of the base particles with a resin. Such coated particles are used as various fillers or modifiers in films, adhesives, adhesives, paints and the like.

As one of the coated particles, an insulating coated conductive particle in which the surface of conductive particles having a metal surface is coated with an insulating resin is known. In addition, in the anisotropic conductive film and the anisotropic conductive adhesive produced by dispersing the insulating coated conductive particles in the adhesive, since the insulating resin used for covering can prevent the electric conduction between adjacent conductive particles, it is possible to improve the connection reliability .

As such insulating-coated conductive particles, for example, JP-A-7-105716 discloses an insulating-coated conductive particle in which an insulating layer is formed on the surface of conductive particles by hybridization. For example, Japanese Patent Application Laid-Open No. 2003-26813 discloses an insulating coated conductive particle having a particle diameter smaller than that of the conductive particle and coated on the surface of the conductive particle, . When the surface of the conductive particles is covered with insulating coating particles, mainly polymer particles or silica particles are used.

Japanese Unexamined Patent Publication (Kokai) No. 2005-203319 discloses an insulating coated particle by hollow particles. Further, Japanese Patent Application Laid-Open No. 2005-149764 discloses coated conductive particles coated with core shell particles.

When the polymer particles are used as insulating coating particles, even when the polymer particles have a bonding functional group, the particle surfaces are dissolved in the solvent at the time of resin kneading and the insulating coating particles are easily peeled off from the surface of the conductive particles. . Further, since the polymer particles have low heat resistance and a large coefficient of thermal expansion, connection reliability tends to deteriorate.

On the other hand, when the silica particles are used as insulating coating particles, they have high elasticity and are hardly deformed, and thus have good insulating properties. Further, the silica particles are characterized by high solvent resistance. However, when the anisotropic conductive film is low-pressure-mounted, the continuity tends to be lowered. Although silicon particles are considered as a substitute material for silica particles, they are not employed because there is a problem in the monodispersibility of particle diameters.

Further, the insulation-coated particles of Japanese Patent Application Laid-Open No. 2005-203319 are susceptible to conduction inhibition due to the presence of bubbles in the particles, and also adsorb compounds incorporated in solvents and other resins, There is a case.

Further, since the insulating coating particles used in the coated conductive particles of Japanese Patent Application Laid-Open No. 2005-149764 are polymer particles, they have low solvent resistance like the above polymer particles, and when the coated conductive particles are mounted as an anisotropic conductive film, And the insulating property tends to be lowered.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide an anisotropic conductive material which can conductively connect electrodes of oppositely arranged circuit members with high reliability and can reliably prevent the conductive between adjacent electrodes to be insulated It is an object of the present invention to provide useful insulating coating particles and insulating coated conductive particles having the particles. It is still another object of the present invention to provide an anisotropic conductive material including the above-mentioned insulating coated conductive particles and a connecting structure connected to circuit members by using the same.

The present invention has found that insulating covering particles having a structure having a core layer containing an organic polymer and a shell layer containing a silicon-based compound as particles for covering base particles are useful as means for solving the above problems.

That is, the present invention relates to an insulating coating particle for forming insulating coated conductive particles by covering a base particle including a metal having conductivity on its surface, and having a core shell structure having core particles and a shell layer, comprises an organic polymer and, syelcheung the SiO _4/2 units, RSiO _3/2 units and R ₂ is selected from the group consisting of SiO _{2/2 units,} an insulating coating particles comprising a silicone compound having at least one kind of units to provide. Here, R represents at least one member selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group and a? - (meth) acryloxypropyl group. In the present specification, the "silicon compound" is a name including silicon and silica.

The insulating coating particles can be used for covering the surface of conductive particles. This makes it possible to conductively connect the electrodes of the oppositely arranged circuit members with high reliability and to obtain an anisotropic conductive material which can reliably prevent the conductive between adjacent electrodes to be insulated. Further, by forming a silica film or a silicon film as the shell layer, solvent resistance and heat resistance can be imparted.

When the silica film is formed as the shell layer, the shell layer is broken even in the low-pressure mounting, so that the continuity is improved. In addition, since the appearance is elastic in a direction different from the direction of compression when mounted, high insulation can be obtained. Further, since silica can be surface-treated, the dispersibility of the particles can be improved according to the binder resin described later.

When a silicon film is formed as a shell layer, the insulating coating particles are easily deformed even under low compression, so that the conductivity is improved. Further, the dispersibility of the insulating-coated conductive particles in the resin can be improved by the characteristics of silicon, and the hygroscopicity can also be reduced.

The shell layer preferably has a functional group having bonding property to the base particles. By having the shell layer having a bonding functional group, not only the insulating coating particles can uniformly form a covalent bond to the base particles but also the adhesion between the shell layer and the base particles is improved.

Here, when the above-mentioned "functional group having bonding property to the base particle" is an epoxy group or a glycidyl group, it is preferable because the insulating coating particles can easily form a covalent bond to the base particles imparted with an amino group or the like.

Further, it is preferable that the shell layer is treated with a silicone oligomer having an epoxy group or a glycidyl group. The surface treatment of the shell layer using a silicone oligomer having an epoxy group or a glycidyl group makes it possible to improve the ease of adsorption to the base particles and the adhesion. Such a surface treatment is particularly preferable when the shell layer does not have a surface functional group.

The thickness of the shell layer is preferably 1 to 150 nm. In this case, by using the insulating coated conductive particles coated with the insulating coating particles of the present invention, the conduction resistance between the circuits connected becomes better.

In addition, taking, isolated blood of the present invention particles, syelcheung is composed of a silicone compound having only SiO _4/2 units, can be a thickness of syelcheung with 1 to 50 nm. In this case, the characteristics of the core particle can be utilized.

The insulating coating particles of the present invention preferably have an average particle diameter of 1 占 퐉 or less and a variation coefficient (C.V.) of particle diameter of 10% or less. When the average particle diameter is 1 占 퐉 or less, both the conductivity and the insulating property can be achieved at the time of compression of the anisotropic conductive material produced by using the insulating coated conductive particles coated with the insulating covering particles of the present invention. Further, by making the coefficient of variation (C.V.) of the particle size of the conductive particles 10% or less, it is possible to improve the reproducibility of the insulating characteristics.

It is preferable that the insulating coating particles of the present invention have a moisture absorption rate of 5 mass% or less. This makes it possible to suppress the occurrence of short-circuiting due to ion migration or the like.

In the insulating coating particles of the present invention, the concentration of the eluted ammonium ion is preferably 100 ppm or less. This makes it possible to suppress the occurrence of curing inhibition in the anisotropic conductive material produced by using the insulating coated conductive particles coated with the insulating coating particles of the present invention.

Further, it is preferable that the shell layer is formed by a reaction using a tertiary amine or a sulfonic acid compound as a catalyst.

Further, it is preferable that the surface of the core particle has an amino group or a carboxyl group. According to this, the shell layer can be easily formed on the surface of the core particle by the hydrogen bonding of the hydrolyzed silanol group at the time of formation of the shell layer.

Further, it is preferable that the core particle has a functional group having a pionic function. According to this, it is possible to prevent elution of counter ions.

The present invention also provides an insulating coated conductive particle comprising the insulating covering particles and base particles at least a part of which is covered with insulating coating particles. The present invention also provides an anisotropic conductive material comprising an insulating binder resin and the insulating coated conductive particles dispersed in an insulating binder resin. According to such insulating-coated conductive particles or anisotropic conductive materials, it is possible to electrically connect the electrodes of the oppositely arranged circuit members with high reliability, and to sufficiently prevent the conductive between adjacent electrodes to be insulated.

The present invention also relates to a circuit device comprising a pair of oppositely disposed circuit members and a cured product of the anisotropic conductive material, the circuit electrodes of the circuit members being electrically connected to each other via the pair of circuit members, And a connecting portion for bonding the members together. Since the connecting portion of the connecting portion includes the cured product of the anisotropic conductive material of the present invention, it is possible to conductively connect the electrodes of the circuit member with high reliability, and to sufficiently prevent the conductivity between adjacent electrodes to be insulated can do.

According to the present invention, it is possible to electrically connect the electrodes of the oppositely disposed circuit members with each other with high reliability, and to provide an anisotropic conductive material which is useful for obtaining an anisotropic conductive material which can reliably prevent the conductive between adjacent electrodes, It is possible to provide the particles and the insulating coated conductive particles having the particles. Further, the present invention can provide an anisotropic conductive material containing the insulating-coated conductive particles and a connection structure in which circuit members are connected to each other by using the anisotropic conductive material. In other words, according to the present invention, it is possible to conduct the conductive connection with which the conduction resistance, the insulation reliability and the connection reliability between the substrates become good, and the leakage between adjacent particles can be prevented.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a cross-sectional view schematically showing an embodiment of an insulating coated conductive particle. FIG. 2 is a cross-sectional view schematically showing an embodiment of the anisotropic conductive material. 3 is a cross-sectional view schematically showing an example of a connection structure in which circuit electrodes are connected to each other. 4 is a cross-sectional view schematically showing an example of a manufacturing method of a connection structure.

Preferred embodiments of the present invention will be described in detail. As shown in Fig. 1, the insulating coating particles 1 of the present embodiment cover the surface of the base particles 2 and constitute insulating coated conductive particles 10. Fig. Hereinafter, each configuration will be described.

≪ Insulating Coating Particles >

[Core shell structure]

As shown in Fig. 1, the insulating coating particles 1 have a core shell structure composed of core particles 1a and a shell layer 1b formed on the surface of the core particles 1a. As the material of the core particle 1a and the shell layer 1b, the core particle 1a contains an organic polymer, and the shell layer 1b includes a silicone compound. By appropriately selecting the kinds of the materials constituting the core particles 1a and the shell layers 1b, it is possible to adjust the thermal characteristics of the insulating coating particles 1, so that the particles are easily deformed, The continuity is improved. Further, other combinations of the materials of the core particles (1a) and the shell layer (1b) can be appropriately selected on the basis of thermal characteristics, optical characteristics, mechanical properties, and the like as necessary.

[Core particle]

The core particle is an insulating particle containing an organic polymer. The organic polymer is not particularly limited as long as it has an insulating property. For example, a resin used for base particles described later may be used.

Examples of polymerizable monomers that can be used in the production of the core particles include the following non-crosslinkable monomers and crosslinkable monomers.

Specific examples of the non-crosslinkable monomer include: i) at least one monomer selected from the group consisting of styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, -Dimethylstyrene, p-tert-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, , styrene such as p-chlorostyrene and 3,4-dichlorostyrene, (ii) styrene such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, Octyl acrylate, dodecyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl a-chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate , Isobutyl methacrylate, hexyl methacrylate, 2-ethyl methacrylate (Meth) acrylic acid esters such as hexyl, n-octyl methacrylate, decyl methacrylate, lauryl methacrylate, and stearyl methacrylate; (iii) vinyl (meth) acrylates such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate (Iv) N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone, (v) vinylidene fluoride, vinylidene fluoride, tetrafluoroethylene, (Meth) acrylate esters containing fluorinated alkyl groups such as hexafluoropropylene, trifluoroethyl acrylate and tetrafluoropropyl acrylate, and (vi) conjugated dienes such as butadiene and isoprene.

Specific examples of the crosslinkable monomer include divinyl compounds such as divinylbenzene, divinylbiphenyl and divinylnaphthalene; (Meth) acrylates such as (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and (poly) tetramethylene glycol di Rate; (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,8-octanediol di (meth) (Meth) acrylate, 2-methyl-1,5-pentanediol di (meth) acrylate, 2,4-diethyl-1,5-pentanediol di (Meth) acrylate such as ethyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, butyl acrylate, butyl acrylate, butyl acrylate, butyl acrylate, (Meth) acrylate; Acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylol propane tetra (meth) acrylate, pentaerythritol tri (Meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) Acrylate, 1,1,1-trishydroxymethylethanedi (meth) acrylate, 1,1,1-trishydroxymethylethanetri (meth) acrylate, 1,1,1-trishydroxymethylpropane Triacrylate, diallyl phthalate and isomers thereof, and triallyl isocyanurate and derivatives thereof.

Further, a silyl group-containing monomer may also be used as the crosslinkable monomer, and specifically,? -Methacryloxypropyltrimethoxysilane,? -Methacryloxypropyltriethoxysilane,? -Methacryloxypropylmethyldimethoxysilane ,? -methacryloxypropylmethyldiethoxysilane,? -acryloxypropylmethyldimethoxysilane,? -methacryloxypropylbis (trimethoxy) methylsilane, 11-methacryloxyundecamethylenetrimethoxysilane, Vinyltrimethoxysilylstyrene, vinyltriethoxysilane, vinyltriethoxysilane, 4-vinyltetramethylenetrimethoxysilane, 8-vinyloctamethylenetrimethoxysilane, 3-trimethoxysilylpropyl vinyl ether, vinyltriacetoxysilane, p-triethoxysilyl-? -methylstyrene,? -acryloxypropyltrimethoxysilane, vinyltrimethoxysilane, and? -trimethoxysilyl-? -methylstyrene, p- beta (N-vinylbenzylaminoethyl-gamma-amide Propyl), and the silane and hydrochloride.

These monomers may be used singly or in combination of two or more.

The core particles can be produced by a conventional method without any particular limitation, and examples thereof include emulsion polymerization, phase-inversion emulsion polymerization, soap-free emulsion polymerization, micro-suspension polymerization, mini-emulsion polymerization, May be used. Of these, the emulsion polymerization method or the soap-free emulsion polymerization method is preferable because it is easy to control the particle diameter and is suitable for industrial production. Further, commercially available core particles may be used.

In the production of the core particles, the content of the polymerizable monomer in the reaction solution is preferably 1 to 50% by mass, more preferably 2 to 30% by mass, still more preferably 3 to 20% by mass %, And most preferably 3 to 15 mass%. When the cross-linked spherical polymer fine particles are produced, aggregation of the particles is not extremely increased even if the amount of the monomers in the reaction system is increased as in the conventional method. However, if the content of the raw monomer is 50% by mass or less, And it is easy to obtain in a yield. On the other hand, if the content of the raw material monomer is 1% by mass or more, it does not require a long time until the reaction is completed, which is practical from an industrial point of view.

The reaction temperature at the time of polymerization varies depending on the type of the solvent to be used and is generally from 10 to 200 캜, preferably from 30 to 130 캜, more preferably from 40 to 90 캜 to be. The reaction time is not particularly limited as long as it is the time required for the intended reaction to be almost completed, and depends largely on the monomer species and the amount thereof, the kind of the functional group, the viscosity and concentration of the solution, For example, when the reaction temperature is 40 to 90 ° C, the reaction time is preferably 1 to 72 hours, more preferably 2 to 24 hours.

The core particle has a carboxyl group, an amino group, or both on the surface, so that it becomes easy to form a shell layer around the core particle. This is because the silicone compound hydrolyzed to the core particles is easily adsorbed by electrostatic interaction and hydrogen bonding. In this respect, it is particularly preferable that the compound has a pionic functional group. In order to introduce these functional groups into the core particles, it is preferable to use a monomer or an initiator containing a carboxyl group or an amino group. In order to improve the dispersibility of the particles, it is preferable to introduce a functional group containing a sulfonic acid group.

Specific examples of the monomer having a carboxyl group include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, maleic acid and fumaric acid, itaconic acid mono C1 to 8 alkyl esters such as monobutyl itaconate ; Maleic acid mono C1 to 8 alkyl esters such as maleic acid monobutyl, and vinyl group-containing aromatic carboxylic acids such as vinyl benzoic acid, and salts thereof. These compounds may be used singly or in combination of two or more, and they may have counter ions such as Na by neutralization.

Specific examples of the monomer having an amino group include aminoethyl acrylate, N-propylaminoethyl acrylate, (meth) acrylate-N-ethylaminopropyl, (meth) (Meth) acrylic acid alkyl ester derivatives such as cyclohexylaminoethyl, etc., allylamine derivatives such as allylamine and N-methylallylamine, amino group-containing styrene derivatives such as p-aminostyrene, 2-vinyl-4,6 -Diamino-S-triazine, and 1,3-propane sultone adducts of dimethylaminoethyl methacrylate. Among them, a compound having a primary or secondary amino group is preferable. These compounds may be used singly or in combination of two or more.

A quaternary ammonium salt may also be used. Specific examples of the monomer having a quaternary ammonium (salt) group include quaternarized tertiary amines with a quaternizing agent such as C1-12 alkyl chloride, dialkyl sulfuric acid, dialkyl carbonate, benzyl chloride and the like have. Specific examples thereof include 2- (meth) acryloyloxyethyltrimethylammonium chloride, 2- (meth) acryloyloxyethyltrimethylammonium bromide, (meth) acryloyloxyethyltriethylammonium chloride, (meth) acryloyl (Meth) acryloylaminoethyltrimethylammonium chloride, (meth) acryloyloxyethylmethylmorpholinoammonium chloride, alkyl (meth) acrylate quaternary ammonium salts such as (meth) acryloylaminoethyltrimethylammonium chloride, (Meth) acryloylaminoethyltrimethylammonium chloride, and (meth) acryloylaminoethyldimethylbenzylammonium chloride; quaternary ammonium salts such as acryloylaminoethyltrimethylammonium bromide, (meth) acryloylaminoethyltriethylammonium chloride and Allyl ammonium methyl sulfate, trimethylvinylphenyl ammonium chloride, tetrabutylammonium (meth) acrylate, trimethylbenzene (Meth) acrylate, 2- (methacryloyloxy) ethyltrimethylammonium dimethylphosphate, and the like.

As the divalent monomer, acrylate having sulfobetaine or carbobeta popularity can be used. Specific examples thereof include sulfobetaine meta (ac) acrylate, sulphobetaine acrylamide, sulphobetaine vinyl compound, sulphate Carboxybetaine acrylate, carboxybetaine vinyl compound, carboxybetaine epoxide, and the like can be given.

A sulfonic acid group-containing monomer for introducing a sulfonic acid group-containing functional group can be used. (Meth) allylsulfosuccinic acid esters, sulfopropyl (meth) acrylates, and the like; aromatic sulfonic acids such as styrenesulfonic acid and? -Methylstyrenesulfonic acid; (Meth) acryloylamino-2,2-dimethyl (meth) acrylate such as 2-hydroxypropyl (meth) acrylate, (Meth) acryloyloxy-2-methylpropanesulfonic acid, 3- (meth) acryloyloxyethanesulfonic acid, 3- (meth) acryloyloxy- ) Acrylamide-2-hydroxypropanesulfonic acid and unsaturated esters containing sulfonic acid groups, and salts thereof.

These monomers may be used singly or in combination of two or more. These monomers are preferably used in an amount of 0.1 mol% to 5 mol%, more preferably 0.1 mol% to 2.5 mol%, and still more preferably 0.1 to 1 mol%, from the viewpoint of improving monodispersibility Do.

In addition, the following disclosure system can be used. For example, 2'-azobis {2- [N- (2-carboxyethyl) amidinopropane, 2,2'-azobis [2- (phenylamidino) propane] dihydrochloride (VA- Azobis {2- [N- (4-chlorophenyl) amidino] propane} dihydrochloride (VA-546, manufactured by Wako Pure Chemicals), 2,2'-azobis Azobis [2- (N-benzylamidino) propane} dihydrochloride (VA-548, manufactured by Wako Pure Chemicals), 2,2'- (VA-553, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2'-azobis [2- (N-allylamino) propane] dihydrochloride Azobis {2- [N- (4-hydroxyethyl) amidino] propane) 2'-azobis (2-amidinopropane) dihydrochloride (V- } Dihydrochloride (VA-558, manufactured by Wako Pure Chemical Industries, Ltd.) and 2,2-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride (VA-041, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2-azobis [2- (2-imidazolin- Diazepin-2-yl) propane] dihydrochloride (VA-054, manufactured by Wako Pure Chemicals), 2,2- Azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride (VA-058, manufactured by Wako Pure Chemicals), 2,2- 2-yl) propane] dihydrochloride (VA-059, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2-azobis {2- [1- 2- (2-imidazolin-2-yl) propane} dihydrochloride (VA-060, manufactured by Wako Pure Chemicals) Azobis [N- (2-carboxyethyl) -2-methylpropionamidine] (VA-057, manufactured by Wako Pure Chemical Industries, Ltd.) , Potassium peroxydisulfate (manufactured by Wako Pure Chemical Industries, Ltd.) and ammonium peroxidesulfate (Manufactured by Wako Pure Chemical Industries, Ltd.). These may be used singly or in combination of two or more. In the case where a polymerizable monomer having a particle active hydrogen group or a hydrophilic functional group is not used, it is preferable to use a compound having an active hydrogen group or a hydrophilic functional group among the initiators in order to improve the dispersibility of the particles. When a radical polymerization initiator is used, the amount thereof is usually from 0.01 to 1 mol% based on the polymerizable monomer. By producing the core particles by the conventional radical polymerization method, the monodispersibility of the finally obtained insulating coating particles can be improved. An amino group or a carboxyl group may be imparted by adsorbing a polymeric dispersant or a surfactant on the core particles.

An emulsifier may be used in combination to improve the dispersibility of the core particles. In the present embodiment, an anionic emulsifier or a nonionic emulsifier is preferably used. Specific examples of the anionic emulsifier include sodium alkylbenzenesulfonate, sodium laurylsulfonate, potassium oleate, and the like, and sodium dodecylbenzenesulfonate is particularly preferably used. Specific examples of the nonionic emulsifier include, for example, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, and the like.

The glass transition temperature (Tg) of the core particles can be arbitrarily adjusted by selecting a polymerizable monomer to be used and by copolymerizing two or more kinds of polymerizable monomers having different Tg's. For example, examples of the polymerizable monomer having a Tg or a softening point temperature of 60 占 폚 or less include isobutyl methacrylate, glycidyl methacrylate, and the like. The Tg can be lowered to 60 占 폚 or less by copolymerizing styrene, methyl methacrylate or the like having a Tg of 60 占 폚 or more and butyl acrylate or dodecyl methacrylate having a Tg of less than 60 占 폚 at an appropriate ratio. Examples of the resin having a Tg of 80 占 폚 or more include styrene,? -Methylstyrene, methyl methacrylate, and t-butyl methacrylate. These may be used singly or in combination of two or more. Further, in order to prevent elution of the core particles into the solvent, the amount of the crosslinkable monomer to the incompatible monomer is preferably less than 5 mol%.

[Shell layer]

Syelcheung comprises a silicon-based compound, has at least a unit of one member selected from the group consisting of SiO _4/2 units, RSiO _3/2 units and R ₂ SiO _2/2 units. The plural Rs may be the same or different.

SiO _4/2 units, RSiO _3/2 units and R ₂ SiO _2/2 units, to can be represented by the following formula.

As the raw material for SiO _4/2 units in the silicone-based compound includes, for example, silicon tetrachloride, tetraalkoxy silane, one member selected from the group consisting of water glass and a metal silicate or a combination of two or more. Specific examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and condensates thereof. These may be used alone or in combination of two or more.

R in RSiO _3/2 units in the silicone compound is at least one member selected from the group consisting of an aromatic group, a vinyl group, and γ- (meth) acryloxypropyl group of 1 to 4 carbon atoms, 6 to 24 carbon atoms. Depending on the substrate, there may be a case where R is an organic group having a small amount of a vinyl group, a? - (meth) acryloxypropyl group or an SH group, and a large amount of an alkyl group or an aromatic group. RSiO _{3 /} As the raw material of the _second unit, for example, methyl trimethoxysilane, methyl triethoxysilane, methyl trimethoxysilane propoxy silane, ethyl trimethoxysilane, ethyl triethoxysilane, ethyl tree propoxysilane, phenyltrimethoxysilane Methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, 3,3,3-triisopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, Fluoropropyltrimethoxysilane, etc. These can be used alone or in combination of two or more.

Silicon-based compound in the R ₂ SiO _2/2 unit As the raw material of (R is, can be selected from the same group as R in RSiO _3/2 units), for example, dimethyl dimethoxysilane, diphenyl dimethoxysilane, methylphenyl dimethoxysilane Methylphenyldiethoxysilane, diethyldimethoxysilane, ethylphenyldimethoxysilane, diethyldiethoxysilane, ethylphenyldiethoxysilane and the like, hexamethylcyclotrisiloxane ((meth) acryloxypropyltrimethoxysilane, Cyclic compounds such as cyclopentyl cyclopentasiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6) and trimethyltriphenylcyclotrisiloxane, Mercaptopropylmethyldimethoxysilane,? -Mercaptopropylmethyldimethoxysilane,? -Methacryloxypropylmethyldimethoxysilane, vinylmethyldimethoxysilane, 3,3,3-trifluoropropylmethyldimethoxysilane, and the like. These may be used alone or in combination of two or more.

In the present embodiment, a small amount of R ₂ SiO _2/2 units can be mixed in the case where the particles are desired to have flexibility. Isolated silicon compound R ₂ SiO ratio of _2/2 units in a coating on the particles is not more than 50 mole% as preferable, based on the total amount of the silicon-based compound, and more preferably not more than 10 mol%. R ₂ SiO ratio of _2/2 units is 50 mol% or less does not become the final particles is too flexible, thereby improving the shape retention. In addition, the lower limit of the ratio of R ₂ SiO _2/2 units in the silicone-based compound is 0% by mol.

As the silicone compound, a small amount of R ₃ SiO _1/2 unit may be used within the range not to impair the effect of the present embodiment. The ratio of R ₃ SiO _1/2 units in the silicone compound is preferably not more than 50 mol%, more preferably not more than 1 mol%. When the proportion of R ₃ SiO _1/2 units is 5 mol% or less, the heat resistance of the final silicone-based fine particles is more excellent. In addition, the lower limit of the ratio of R ₃ SiO _1/2 units in the silicone-based compound is 0% by mol.

[Method for producing insulating coating particles]

Insulating coating particles, for example, in the case syelcheung the silicon, the core particle and the shell SiO with respect to the solvent containing the formed catalyst _4/2 units of raw materials, RSiO _3/2 units of raw materials, and R ₂ SiO _2/2 units And an emulsion obtained by emulsifying a mixture of water and a mixture with a line mixer or a homogenizer are added collectively or continuously to obtain insulating coated particles coated with silicone. When the stability and the particle size distribution of the latex phase are emphasized, it is preferable to adopt continuous addition. When the acid catalyst is added before the emulsion is added and the continuous addition is carried out under the condition that the hydrolysis and the condensation reaction proceed immediately, the insulating coating particles grow large with time and exhibit a narrow particle size distribution as in the case of ordinary seed polymerization Can be obtained. Further, when continuous addition is performed for a relatively short period of time of 30 minutes to 1 hour, comparatively good productivity and narrow particle size distribution can be achieved at the same time.

Isolated in syelcheung the silica coating particles are prepared, for example, by adding a SiO _4/2 units of the raw material and the uniform mixture of the water / alcohol or an alcohol with respect to the solvent containing the core particles and the shell forming the catalyst in a batch or continuous can do.

When the insulating coating particles of the present embodiment are used as anisotropic conductive materials as described later, the lower limit of the particle diameter of the insulating coating particles is preferably 10 nm and the upper limit thereof is 1 占 퐉, more preferably 30 nm, The upper limit is 500 nm. If the particle size is 5 nm or more, the distance between the adjacent coated conductive particles becomes larger than the hopping distance of electrons, and leakage is less likely to occur. If the particle diameter is 1000 nm or less, pressure and heat required for pressing can be reduced.

In addition, since small particles can enter the gaps covered by the large insulating coating particles to improve the coating density, two or more kinds of insulating coating particles having different particle diameters can be used in combination. At this time, it is preferable that the particle diameter of the small insulating coating particles is 1/2 or less of the particle size of the large particles, and the number of small particles is preferably 1/4 or less of the number of large particles.

[Functional group having bonding property]

In the coated conductive particle of the present embodiment, it is preferable that the shell layer partially covers the surface of the base particle through a functional group having bonding property to the base particle. In this case, the insulating coating particles are chemically bonded to the base particles, so that the bonding force is stronger than that due to the Van der Waals force or the electrostatic force only, and the conductive particles (insulating coated conductive particles) When used for a conductive material, it is possible to prevent the particles for insulating coating from peeling off when kneading to a binder resin or the like, or to prevent leakage of the insulating coating particles due to contact with adjacent insulating coated conductive particles. This chemical bond is formed only between the base particles and the insulating coating particles, and since the insulating coating particles do not bond to each other, the base particles are covered with the insulating coating particles of a single layer. From this, it can be easily made that the diameter of the insulating coated conductive particles is uniform by using those having a uniform particle size as the base particles and the insulating coating particles.

The functional group is not particularly limited as long as it is a covalent bondable group and examples thereof include a silanol group, a carboxyl group, an amino group, an ammonium group, a hydroxyl group, a carbonyl group, a thiol group, a sulfonic acid group, a sulfonium group, an epoxy group and a glycidyl group. It is preferable from the viewpoint of the rate of the reactivity. The functional group may be imparted by mixing the silane compound having the functional group at the time of forming the shell, or by treating the surface of the shell layer with a surfactant or a polymer dispersant. Further, from the viewpoint of improving the adsorptivity to the conductive particles, it is preferable to treat the surface of the shell layer with the oligomerized silane compound having the functional group (silicone oligomer).

[Shell forming catalyst]

The shell-forming catalyst refers to a catalyst used in a sol-gel reaction of a silicon alkoxide, and an acid or an alkali is used. Examples of the acid catalyst include sulfonic acids such as aliphatic sulfonic acids, aliphatic substituted benzenesulfonic acids and aliphatic substituted naphthalenesulfonic acids, and inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid. Of these, aliphatic substituted benzenesulfonic acids are preferable, and n-dodecylbenzenesulfonic acid is particularly preferable from the viewpoint of excellent emulsion stability of the organosiloxane. Specific examples of the alkali catalyst include methylamine, etheramine, ethylamine, trimethylamine, triethylamine, triethanolamine, N, N-diisopropylethylamine, piperidine, piperazine, morpholine, quinuclidine, 1 , 4-diazabicyclo [2.2.2] octane (DABCO), pyridine, 4-dimethylaminopyridine, ethylenediamine, tetramethylethylenediamine (TMEDA), hexamethylenediamine, aniline, catecholamine, -Bis (dimethylamino) naphthalene (proton sponge), amino acid, amantadine, spermidine, spermine and the like. Particularly, it is preferable to use a compound having a tertiary amino group, and it is particularly preferable to use triethylamine.

[Average Particle Size, Coefficient of Variation of Particle Size (C.V.) and Thickness of Shell Layer]

The average particle diameter of the insulating coating particles is an average value obtained by observing 100 particle diameters with a scanning electron microscope (SEM). The average particle diameter of the insulating coating particles varies depending on the particle size of the base particles and the intended use of the insulating coating conductive particles, but is preferably 1 占 퐉 or less. As a result, the physical properties of the base particles are hardly controlled by the physical properties of the insulating coating particles, and the effect of using the base particles is easily obtained. More preferably, the lower limit of the particle diameter of the insulating coating particles is 10 nm, and the upper limit thereof is 1 占 퐉.

The variation coefficient (C.V.) of the particle diameter is calculated using the following equation (1).

&Quot; (1) "

C.V. = {(Standard deviation of particle diameter) / (average particle diameter)} x 100 (%)

The C.V. is preferably 10% or less for improving the characteristics, more preferably 7% or less, and most preferably 5% or less. When the CV is 10% or less, the size of the obtained insulating coated conductive particles becomes uniform, and when the insulating coated conductive particles are used for the anisotropic conductive material, pressure is easily applied uniformly when pressed between the substrates, .

The particle diameter of the core particle and the thickness of the shell layer in the insulating coating particles are not particularly limited, but preferably the thickness of the shell layer is 1/100 or more, more preferably 1/50 or more of the particle diameter of the core particle. Further, when the syelcheung is composed only of SiO _4/2 units, the thickness of the syelcheung preferably ranges from 1 to 50 nm. When the thickness is 50 nm or less, the physical properties of the insulating coating particles are hardly controlled by the physical properties of the shell layer, the insulating coating particles are easily deformed, and the surface of the base particles is easily exposed. Therefore, Thereby making it difficult to cause conduction failure.

[Amount of eluted ammonium ion]

When the ammonium ion is eluted from the insulating coating particles, the curing agent in the anisotropic conductive material produced using the insulating coating conductive particles may be inactivated and curing inhibition may occur. Therefore, the concentration of ammonium ions eluted from the insulating coating particles is preferably 150 ppm or less, and more preferably 100 ppm or less. The eluted ammonium ion concentration can be measured, for example, by dispersing 0.5 g of the particles for insulation coating after drying in 25 g of ion-exchanged water and allowing to stand at 100 캜 for 12 hours in a pressure-resistant vessel, followed by ion chromatography.

[Absorption rate]

The moisture absorption rate of the insulating coating particles is preferably 5 mass% or less. When the moisture absorption rate is 5 mass% or less, it is possible to suppress the occurrence of shot due to ion migration or the like. The moisture absorption rate can be calculated, for example, by measuring the weight of the insulating coating particles in a high-temperature and high-humidity test tank (temperature: 60 ° C, humidity: 90%) for 18 hours and then measuring particle weight again.

≪ Base particles &

The base particles include a metal whose surface has conductivity and function as conductive particles. In this case, as shown in Fig. 1, the base particles 2 may be formed by forming a layer 2b of a conductive metal on the surface of a spherical core particle 2a containing an inorganic compound or an organic compound to be described later And may be metal particles containing only a conductive metal. Among them, the formation of the conductive metal layer on the surface of the spherical core material particles containing the organic compound is preferable from the viewpoint of the connection stability since the bonding area can be increased by deforming at the time of press bonding when the substrates are electrically connected.

Examples of the metal having conductivity include, but not limited to, gold, silver, copper, platinum, zinc, iron, tin, lead, aluminum, palladium, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, Cadmium, and the like, and metal compounds such as ITO and solder.

When the metal layer including the metal having conductivity is formed on the surface of the spherical core material particles containing the organic compound, the metal layer may have a single layer structure or a laminated structure including a plurality of layers. In the case of including a laminated structure, the outermost layer preferably contains gold, palladium or nickel. Since the outermost layer contains palladium or gold, the coated particles obtained are more excellent because of high corrosion resistance and small contact resistance.

The method of forming the conductive metal layer on the surface of the spherical core material particles containing the organic compound is not particularly limited and known methods such as physical metal vapor deposition method and chemical electroless plating method can be mentioned, The electroless plating method is preferable. Examples of the metal layer that can be formed by electroless plating include gold, silver, copper, platinum, palladium, nickel, rhodium, ruthenium, cobalt, tin and alloys thereof. It is preferable that a part or all of the metal layer is formed by electroless nickel plating since a single coating can be formed at a high density.

The method of forming the gold layer on the outermost layer of the metal layer is not particularly limited and examples thereof include known methods such as electroless plating, displacement plating, electroplating, and sputtering.

The thickness of the metal layer is not particularly limited, but the lower limit is preferably 0.005 mu m, and the upper limit is preferably 2 mu m. When the thickness of the metal layer is less than 0.005 mu m, a sufficient effect as a conductive layer may not be obtained. When the thickness exceeds 2 mu m, the specific gravity of the obtained insulating coated conductive particles becomes excessively high, The hardness may not be a hardness that can be sufficiently deformed already. A more preferable lower limit of the thickness of the metal layer is 0.01 mu m, and a more preferable upper limit is 1 mu m.

When the outermost layer of the metal layer is a gold or palladium layer, the preferable lower limit of the thickness of the gold or palladium layer is 0.001 mu m, and the upper limit is preferably 0.5 mu m. If the thickness of the gold or palladium layer is less than 0.001 mu m, it is difficult to uniformly cover the metal layer and the effect of improving the corrosion resistance and the contact resistance value may not be expected. When the thickness is more than 0.5 mu m, A more preferable lower limit of the thickness of the gold or palladium layer is 0.01 mu m, and a more preferable upper limit is 0.3 mu m.

When the base particles have a layer of the conductive metal formed on the surface of the spherical core material particles, the spherical core material particles are not particularly limited, and for example, particles containing a uniform composition, , And the like. Of these, particles having a multilayer structure are preferable when various characteristics such as mechanical properties and electrical characteristics are to be imparted to the base particles.

The material constituting the spherical core particles is not particularly limited, and inorganic compounds such as known silica, organic compounds and the like can be given. Among them, when the insulating coated conductive particles are used for the anisotropic conductive material, it is possible to increase the junction area between the surface of the base particles and the electrodes by deforming at the time of press-bonding when the substrates are electrically connected, desirable.

Examples of the organic compound include, but are not limited to, polyolefins such as polyethylene, polypropylene, polystyrene, polypropylene, polyisobutylene and polybutadiene, acrylic resins such as polymethyl methacrylate and polymethyl acrylate, Phenol resin such as phenol formaldehyde resin, melamine resin such as melamine formaldehyde resin, benzoguanamine resin such as benzoguanamine formaldehyde resin, urea formaldehyde resin, epoxy resin, ) Saturated polyester resin, polyphenylene oxide, polyacetal, polysulfone, polycarbonate, polyamide, polyimide, polyamideimide, polyetheretherketone, polyether sulfone and the like. Among them, it is preferable to use a resin obtained by polymerizing one kind or two or more kinds of various polymerizable monomers having an ethylenic unsaturated group because it is easy to obtain a preferable hardness.

Specific examples of the non-crosslinkable monomer include: i) at least one monomer selected from the group consisting of styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, -Dimethylstyrene, p-tert-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, , styrene such as p-chlorostyrene and 3,4-dichlorostyrene, (ii) styrene such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, Octyl acrylate, dodecyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl a-chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate , Isobutyl methacrylate, hexyl methacrylate, 2-ethyl methacrylate (Meth) acrylic acid esters such as hexyl, n-octyl methacrylate, decyl methacrylate, lauryl methacrylate, and stearyl methacrylate; (iii) vinyl (meth) acrylates such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate (Iv) N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone, (v) vinylidene fluoride, vinylidene fluoride, tetrafluoroethylene, (Meth) acrylate esters containing fluorinated alkyl groups such as hexafluoropropylene, trifluoroethyl acrylate and tetrafluoropropyl acrylate, and (vi) conjugated dienes such as butadiene and isoprene.

Specific examples of the crosslinkable monomer include divinyl compounds such as divinylbenzene, divinylbiphenyl and divinylnaphthalene; (Meth) acrylates such as (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and (poly) tetramethylene glycol di Rate; (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,8-octanediol di (meth) (Meth) acrylate, 2-methyl-1,5-pentanediol di (meth) acrylate, 2,4-diethyl-1,5-pentanediol di (Meth) acrylate such as ethyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, butyl acrylate, butyl acrylate, butyl acrylate, butyl acrylate, (Meth) acrylate; Acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylol propane tetra (meth) acrylate, pentaerythritol tri (Meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) Acrylate, 1,1,1-trishydroxymethylethanedi (meth) acrylate, 1,1,1-trishydroxymethylethanetri (meth) acrylate, 1,1,1-trishydroxymethylpropane Triacrylate, diallyl phthalate and isomers thereof, and triallyl isocyanurate and derivatives thereof.

These monomers and other polymerizable monomers may be used singly or in combination of two or more. As the method for producing such spherical core particles, conventionally known methods can be used and are not particularly limited, and examples thereof include emulsion polymerization, phase emulsion polymerization, suspension polymerization, dispersion polymerization, seed polymerization, Laws and the like. Among them, a seed polymerization method having excellent controllability of particle diameter is preferable. In addition, commercially available spherical core particles may be used.

≪ Insulating Coated Conductive Particles >

The insulating coated conductive particle of the present embodiment is obtained by covering the surface of the base particle with the insulating covering particles. Here, it is preferable that 20% or less of the surface area of the insulating coating particles is in contact with the surface of the base particles. When the surface area of contact is 20% or less, the deformation of the insulating coating particles is small, the size of the coated conductive particles obtained becomes more uniform, and the shell layer tends not to be broken, so that the core shell structure tends to be easily retained. In addition, the lower limit is not particularly limited, and may be substantially 0% when the insulating coating particles and the base particles are connected by, for example, a polymer having a long chain length.

In the insulating-coated conductive particle of the present embodiment, it is preferable that 5% or more of the surface area of the base particles is covered with the insulating-covering particles. If the coated surface area is 5% or more, it becomes difficult to secure the insulating property of the insulating coated conductive particles. When the insulating coated conductive particles are used for the anisotropic conductive material, the preferable lower limit of the covering ratio of the insulating covering particles is 5%, and the preferable upper limit is 60%. When the covering ratio is 5% or more, it is possible to effectively prevent the leakage of the lateral direction due to the contact of the metal surface of the base particles with the adjacent particles. When the covering ratio is 60% or less, sufficient continuity can be ensured. The covering ratio of the surface of the base particle with the insulating coating particles can be controlled depending on the addition amount (concentration) of the insulating coating particles, the amount (density) of the functional group introduced into the base particle surface, the kind of the reaction solvent and the like.

The covering ratio of the surface of the base particle with the insulating coating particles is a value calculated by the following formula (2).

&Quot; (2) "

Coverage (%) = {(area of the portion of the base particle surface covered with insulating coating particles) / (total surface area of base particle)} x 100

The insulating coated conductive particles can be produced by dry hybridization or wet heteroconjugation. From the viewpoint of the covering ratio and the control of the inter-particle distance, it is preferable to use the wet heterojunction. As a method of using wet-type hetero-aggregation, a method of using a covalent bond or electrostatic attraction between particles is used. It is preferable to use a covalent bond in order to prevent the particles for insulation coating from falling off. The covering ratio can be adjusted by appropriately adjusting the ratio of the conductive particles to the insulating coating particles. Further, when the formation of the covalent bond is slow, it is possible to promote the formation of the covalent bond by heating the solvent.

Concretely, a chemical bond is formed by mixing an insulated coating particle (hereinafter occasionally referred to as " daughter particle ") into which a glycidyl group or an epoxy group is introduced and conductive particles imparted with an amino group to form an insulating coated conductive particle It becomes possible to make it.

Methods for introducing an amino group into conductive particles having a metal layer containing gold or palladium include the following methods. A carboxyl group, an alkoxy group or an alkoxy group on the surface by treating a metal layer surface with a mercapto group, a sulfide group or a disulfide group forming a coordination bond to gold or palladium and a compound having a hydroxyl group, a carboxyl group, an alkoxy group or an alkoxycarbonyl group, And an alkoxycarbonyl group can be introduced. Examples of the compound to be used include mercaptoacetic acid, 2-mercaptoethanol, methyl mercaptoacetate, mercaptosuccinic acid, thioglycerin and cysteine.

The method of treating the surface of the metal layer with the above compound is not particularly limited, but a method in which a compound such as mercaptoacetic acid is dispersed in an organic solvent such as methanol or ethanol at a concentration of about 10 to 100 mmol / L, There is a method of dispersing the particles.

The surface potential (zeta potential) of a particle having a functional group such as a hydroxyl group, a carboxyl group, an alkoxy group and an alkoxycarbonyl group on its surface is usually negative when the pH is in a neutral region. On the other hand, the surface potential of the inorganic oxide particle having a hydroxyl group is usually negative. It is often difficult to sufficiently coat the surface of a particle having a negative surface potential with a particle having a negative surface potential. However, by providing a polymer electrolyte layer therebetween, the insulating coating particles can be efficiently adhered to the conductive particles. In addition, since the polymer electrolyte layer is provided, the insulating coating can be uniformly coated on the surface of the conductive particles without defects, so that the insulating property can be ensured even if the circuit electrode interval is narrow and the connection resistance The effect of lowering is more remarkably exhibited.

As the polymer electrolyte forming the polymer electrolyte layer, a polymer having a functional group electrically charged in an aqueous solution and having a charge in its main chain or side chain can be used, and among these, a polycation is preferable. Examples of the polycation include those having a functional group capable of positively charging such as polyamines, for example, polyethyleneimine (PEI), polyallylamine hydrochloride (PAH), polydiallyldimethylammonium chloride (PDDA), polyvinylpyridine (PVP), polylysine, polyacrylamide, and copolymers containing at least one of these. Among them, the polyethyleneimine has a high charge density and a strong bonding force.

[Silicone oligomer treatment of insulating coated conductive particles]

In the case where the insulating coating particles have a silanol group on the surface thereof, the insulating reliability of the insulating coated conductive particles described later can be improved by treating the silanol coupling agent or the silane coupling agent with a oligomerized silicone oligomer. Further, from the viewpoint of easy reaction to the particle surface, it is preferable to use the silane coupling agent in the form of a silicone oligomer. The silicone oligomer is preferably three-dimensionally crosslinked in advance by a condensation reaction. The silicone oligomer preferably has a hydrophobic group and a functional group that reacts with an inorganic material such as silica.

Silicone oligomers are generally composed of siloxane units having a structure represented by the following formulas.

In the formulas, R ¹ and R ² each independently represent a hydrophobic group. R ¹ and R ² are preferably an alkyl group having 1 or 2 carbon atoms such as a methyl group and an ethyl group, an aryl group having 6 to 12 carbon atoms such as a phenyl group, or a vinyl group. More preferably, R ¹ and R ² are each independently a methyl group or a phenyl group. R ¹ and R ² may be the same or different from each other.

The polymerization degree of the silicone oligomer is usually 3 or more, preferably 5 or more, more preferably 6 or more, further preferably 10 or more. The degree of polymerization of the silicone oligomer is usually 90 or less, preferably 80 or less, more preferably 70 or less, further preferably 50 or less. When the degree of polymerization is increased, uneven treatment is less likely to occur during the surface treatment, and reliability can be improved. If the degree of polymerization is small, the silicone oligomer tends to be easily adhered to a sufficient thickness.

The polymerization degree of the silicone oligomer is calculated by the following formula (3) based on the weight average molecular weight in terms of standard polystyrene determined by gel permeation chromatography (GPC) measurement.

&Quot; (3) "

Polymerization degree = weight average molecular weight / molecular weight of siloxane unit

When a plurality of siloxane units are contained in the silicone oligomer, the degree of polymerization is calculated by the average value thereof.

A three-dimensional crosslinked silicone oligomer is generally preferred to include at least one of a tetrafunctional siloxane unit represented by the castle R ¹ SiO _{3/2 3-functional} siloxane units, sex and SiO _4/2 represented by the following. For example, silicone oligomers, R represented by _² SiO ^{_2/2 2} functional Castle siloxane unit represented by and SiO _{4/2 4,} and may contain the siloxane units functionalized Castle, R _² SiO _^2/2 represented by the And a trifunctional siloxane unit represented by R < ¹ > SiO < _{3 &gt}; _{/ 2} .

The siloxane oligomer preferably contains at least 15 mol% of tetrafunctional siloxane units based on the total siloxane units, more preferably 20 to 60 mol%.

The silicone oligomer can be synthesized by, for example, a method of condensing chloro or alkoxysilane corresponding to a desired siloxane unit in the presence of water using an acid catalyst. The condensation reaction is conducted to such an extent that the silicone oligomer does not become a gel phase before being attached to the submicron polymer particles. For this purpose, the reaction temperature, the reaction time, the composition ratio of the oligomer, the kind and amount of the catalyst are adjusted and adjusted. As the catalyst, acetic acid, hydrochloric acid, maleic acid, phosphoric acid and the like are preferably used.

The silicon oligomer adheres to the submicron polymer particles, and a part thereof is often adhered to the conductive particles. The adhesion amount of the silicone oligomer in the entire insulating coated conductive particles is preferably 0.01 to 10% by mass, more preferably 0.05 to 5.00% by mass, based on the mass of the submicron polymer particles. When the amount of the adhesive is 0.01 mass% or more, the effect of improving the interfacial adhesion tends to be obtained. When the amount is 10 mass% or less, deterioration of the heat resistance can be prevented.

Such insulating coated conductive particles can be used as a so-called anisotropic conductive material for electrically connecting small electric parts such as semiconductor elements to a substrate or electrically connecting the substrates.

≪ Anisotropic conductive material &

By dispersing the insulating coated conductive particles in an insulating binder resin, an adhesive composition can be produced. Further, this adhesive composition can be used as an anisotropic conductive material (circuit connecting material). The anisotropic conductive material may be formed into a film and used as an anisotropic conductive film. The anisotropic conductive film 50 shown in Fig. 2 is obtained by molding an adhesive composition in which insulating coated conductive particles 10 are dispersed in an insulating binder resin 20 in the form of a film.

≪ Connection structure >

The connecting structure 100 shown in Fig. 3 has first and second circuit members 30 and 40 facing each other. The first circuit member 30 and the second circuit member 40, A connecting portion 50a for connecting them is provided.

The first circuit member 30 includes a circuit board 31 and circuit electrodes (first circuit electrodes) 32 formed on the main surface 31a of the circuit board 31. [ The second circuit member 40 includes a circuit board 41 and circuit electrodes (second circuit electrodes) 42 formed on the main surface 41a of the circuit board 41.

Specific examples of the circuit member include an IC chip (semiconductor chip), a chip component such as a resistor chip, a capacitor chip, and a driver IC, and a rigid package substrate. These circuit members are generally provided with circuit electrodes and a plurality of circuit electrodes. As the other circuit member to which the circuit member is connected, a wiring substrate such as a flexible tape substrate having a metal wiring, a flexible printed wiring board, a glass substrate deposited with indium tin oxide (ITO), or the like can be given. By using the anisotropic conductive film 50, these circuit members can be connected efficiently with high connection reliability. Therefore, the anisotropic conductive film 50 is preferable for COG packaging and COF packaging over a wiring board of a chip component having a plurality of fine connection terminals (circuit electrodes).

The connecting portion 50a includes a cured product 20a of an insulating binder resin contained in the circuit connecting material and the insulating coated conductive particles 10 dispersed therein. Further, in the connection structure 100, the opposing circuit electrodes 32 and the circuit electrodes 42 are electrically connected through the insulating-coated conductive particles 10. More specifically, as shown in Fig. 3, in the insulating-coated conductive particles 10, the insulating coating particles 1 are deformed by compression to be in direct contact with both the circuit electrodes 32 and 42 . On the other hand, insulating properties are maintained by interposing the insulating coating particles 1 between the base particles 2 in the transverse direction. Therefore, when the anisotropic conductive film 50 is used, it becomes possible to improve insulation reliability at a narrow pitch of 10 mu m level.

As the insulating binder resin 20, a mixture of a heat-reactive resin and a curing agent is used, and specifically, a mixture of an epoxy resin and a latent curing agent is preferable.

Examples of the epoxy resin include bisphenol type epoxy resins derived from epichlorohydrin and bisphenol A, F and AD, epoxy novolac resins derived from epichlorohydrin and phenol novolak or cresol novolak, and skeletons including naphthalene ring Naphthalene-based epoxy resin having two or more glycidyl groups in one molecule such as glycidylamine, glycidyl ether, biphenyl, alicyclic or the like, or a mixture of two or more kinds thereof It is possible.

For these epoxy resins, it is preferable to use a high purity product in which impurity ions (Na ⁺ , Cl ^- etc.) and hydrolyzable chlorine are reduced to 300 ppm or less. This makes it easy to prevent the electromigration.

Examples of the latent curing agent include imidazole-based, hydrazide-based, boron trifluoride-amine complexes, sulfonium salts, amine imides, salts of polyamines, and dicyandiamides. In addition, a mixture of a radical reactive resin and an organic peroxide or an energy radiation curable resin such as ultraviolet ray is used as the adhesive.

The insulating binder resin 20 may be mixed with a butadiene rubber, an acryl rubber, a styrene-butadiene rubber, a silicone rubber or the like in order to reduce the stress after bonding or to improve the adhesiveness.

In order to make the adhesive composition into a film, it is effective to blend a thermoplastic resin such as a phenoxy resin, a polyester resin or a polyamide resin having film-forming properties into the composition. These film-forming polymers are also effective for relaxation of stress during curing of the reactive resin. Particularly, when the film-forming polymer has a functional group such as a hydroxyl group, it is preferable because the adhesion improves. The film is formed by dissolving or dispersing an adhesive composition comprising an epoxy resin, an acrylic rubber, a latent curing agent and a film-forming polymer in an organic solvent, applying it on a peelable base material (separator film) By removing the solvent. As the organic solvent to be used at this time, a mixed solvent of an aromatic hydrocarbon system and an oxygen-containing system is preferable in that the solubility of the material is improved.

The thickness of the anisotropic conductive film 50 is relatively determined in consideration of the particle size of the insulating coated conductive particles and the characteristics of the adhesive composition, but is preferably 1 to 100 占 퐉. When the thickness is less than 1 mu m, sufficient adhesion can not be obtained. When the thickness exceeds 100 mu m, a large amount of insulating coated conductive particles are required to obtain conductivity, which is not realistic. For this reason, it is more preferable that the thickness is 3 to 50 mu m.

≪ Manufacturing Method of Connection Structure >

4 is a process drawing showing a process of manufacturing the connection structure using an anisotropic conductive material by a schematic sectional view. In this embodiment, a connection structure is manufactured by thermally curing an anisotropic conductive material.

First, the first circuit member 30 and the anisotropic conductive film 50 described above are prepared. The anisotropic conductive film 50 includes an adhesive composition containing the insulating coated conductive particles 10 as described above.

Then, the anisotropic conductive film 50 is placed on the surface on which the circuit electrodes 32 of the first circuit member 30 are formed. The anisotropic conductive film 50 is pressed in the directions of arrows A and B in Fig. 4A to temporarily connect the anisotropic conductive film 50 to the first circuit member 30 (Fig. 4B).

The pressure at this time is not particularly limited as long as it does not damage the circuit member, but it is generally preferably 0.1 to 30.0 MPa. The heating temperature may be set to a temperature at which the anisotropic conductive film 50 is not substantially cured. The heating temperature is preferably 50 to 190 캜. These heating and pressurization are preferably performed in the range of 0.5 to 120 seconds.

4 (c), the second circuit member 40 is placed on the anisotropic conductive film 50 with the second circuit electrode 42 facing the first circuit member 30 Leave. Further, while heating the anisotropic conductive film 50, the whole is pressed in the directions of arrows A and B in Fig. 4 (c).

The heating temperature at this time is set to a temperature at which the anisotropic conductive film 50 can be cured. The heating temperature is preferably 60 to 200 占 폚, more preferably 70 to 190 占 폚, and even more preferably 80 to 160 占 폚. If the heating temperature is lower than 60 ° C, the curing rate tends to decrease. If the heating temperature is higher than 200 ° C, unwanted side reactions tend to proceed. The heating time is preferably 0.1 to 180 seconds, more preferably 0.5 to 180 seconds, further preferably 1 to 180 seconds.

The connecting portion 50a is formed by curing the anisotropic conductive film 50 to obtain the connecting structure 100 as shown in Fig. The conditions of the connection are appropriately selected according to the application to be used, the adhesive composition and the circuit member. When an anisotropic conductive film (50) that is cured by light is used as the insulating binder resin (20), the anisotropic conductive film (50) can be irradiated with an actinic ray or an energy ray appropriately. Examples of the active rays include ultraviolet rays, visible rays, and infrared rays. Examples of the energy ray include electron beams, X-rays,? -Rays, and microwaves.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments.

[Example]

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. The present invention is not limited to the following examples.

<Fabrication of Insulating Coating Particles>

(Production of core particle 1)

The following compounds were charged all at once in a 500 ml flask, and dissolved oxygen was replaced with nitrogen for 1 hour, followed by heating and stirring in a water bath at 70 캜 for about 6 hours to obtain Core Particles 1.

Styrene 40.4 g (388 mmol)

1.6 g of divinylbenzene (12 mmol)

Azobis [N- (2-carboxyethyl) -2-methylpropionamidine] (VA-057)

1.4 g (4 mmol)

1,3-propane sultone adduct of dimethylaminoethyl methacrylate (DMAEMAPS)

0.6 g (2 mmol)

Water 400 g

Observation of the core particle 1 by SEM revealed that the average particle diameter was 262 nm and the coefficient of variation (C.V.) of the particle diameter was 4.1%.

(Preparation of core particles 2 to 4)

Core particles 2 to 4 were prepared in the same manner as the core particles 1 except that the materials listed in Table 1 were used. In Table 1, "KBE-503" represents γ-methacryloxypropyltriethoxysilane (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.).

(Preparation of Insulating Coating Particle 1)

The following compounds were charged in a 500 ml flask at a time and the following shell raw material dispersion 1 was added dropwise over 1 hour while stirring in a water bath at 35 占 폚 and heating and stirring were continued for 6 hours after dropping, To obtain a dispersion of particles.

5 mass% Core particle 1 aqueous solution 100 g

100 g ethanol

2 g of triethylamine

[Shell raw material dispersion 1]

12.5 g of tetraethoxysilane

Ethanol 300 g

The resulting dispersion of insulating coating particles was centrifuged and re-dispersion with methanol was repeated several times. Thereafter, the insulating coating particles were observed by SEM. The average particle diameter was 300 nm and the variation coefficient (C.V.) of the particle diameter was 4.2%. Further, 1 g of the obtained insulating coating particles was allowed to stand in a high temperature and high humidity test tank (temperature: 60 DEG C, humidity: 90%) for 18 hours, and then the particle weight was measured again to calculate the moisture absorption rate. The moisture absorption rate was 1.5% by mass. After drying the obtained particles, 0.5 g of the dispersion was dispersed in 25 g of ion-exchanged water and allowed to stand at 100 캜 for 12 hours in a pressure vessel. The concentration of eluted ammonium ion was measured by ion chromatography to find 15 ppm.

Subsequently, 60 g of? -Glycidoxypropyltrimethoxysilane, 3 g of methanol, 14 g of water and hydrochloric acid (1% by mass of total amount) were mixed and stirred at 60 ° C for 4 hours to obtain a silicone oligomer having a glycidyl group 1 was synthesized. This silicone oligomer 1 was added in the same amount as the particle weight to the dispersion of insulating coating particles and stirred for 2 hours to obtain insulating coating particles 1 whose surface was subjected to silicone oligomer treatment. Thereafter, centrifugal separation was performed three times, and the particles were washed and dispersed in methanol.

(Preparation of Insulating Coating Particles 2)

A dispersion of insulating coating particles was prepared in the same manner as in the synthesis of insulating coating particles 1 except that the amount of tetraethoxysilane in the shell raw material dispersion was doubled. As a result of observation by SEM, the average particle diameter was 325 nm and the variation coefficient (C.V.) of the particle diameter was 4.0%. The moisture absorption rate was calculated to be 2.0% by mass. The eluted ammonium ion concentration was measured to be 31 ppm.

The silicone oligomer 1 was added in the same amount as the particle weight to the dispersion of the insulating coating particles and stirred for 2 hours to obtain an insulating coating particle 2 whose surface was subjected to silicone oligomer treatment. Thereafter, centrifugal separation was performed three times, and the particles were washed and dispersed in methanol.

(Preparation of Insulating Coating Particles 3)

A dispersion of insulating coating particles was prepared in the same manner as in the synthesis of insulating coating particles 1 except that the amount of tetraethoxysilane in the shell raw material dispersion was 3 times. As a result of observation by SEM, the average particle diameter was 363 nm and the coefficient of variation (C.V.) of the particle diameter was 4.4%. The moisture absorption rate was calculated to be 3.0% by mass. The eluted ammonium ion concentration was measured to be 19 ppm.

Further, the silicone oligomer 1 was added to the dispersion of the insulating coating particles in an amount equivalent to the particle weight, and the mixture was stirred for 2 hours to obtain an insulating coating particle 3 whose surface was subjected to silicone oligomer treatment. Thereafter, centrifugal separation was performed three times, and the particles were washed and dispersed in methanol.

(Preparation of Insulating Coating Particles 4)

The following compounds were charged in a 500 ml flask at a time, and the following shell raw material dispersion 2 was added dropwise over 1 hour while stirring in a water bath at 80 占 폚. After dropwise addition, heating and stirring were continued for 5 hours, After that, a dispersion of insulating coating particles was obtained.

2.5 mass% Core particle 1 aqueous solution 200 g

2 g of dodecylbenzenesulfonic acid Na

2 g of dodecylbenzenesulfonic acid

[Shell raw material dispersion 2]

15.0 g of methyltrimethoxysilane

Water 20.0 g

0.1 g of dodecylbenzenesulfonic acid Na

The resulting dispersion of the particles was centrifuged and redispersion in methanol was repeated several times and then observed by SEM. The average particle size was 312 nm and the variation coefficient (C.V.) of the particle size was 4.5%. The moisture absorption rate was calculated in the same manner as in Example 1, and found to be 1.2% by mass. The eluted ammonium ion concentration was measured to be 21 ppm.

The silicone oligomer 1 was added to the dispersion of the insulating coating particles in an amount equivalent to the particle weight, and the mixture was stirred for 2 hours to obtain an insulating coating particle 4 having a surface subjected to a silicone oligomer treatment. Thereafter, centrifugal separation was performed three times, and the particles were washed and dispersed in methanol.

(Preparation of Insulating Coating Particles 5)

The following compounds were charged in a 500 ml flask at a time and the following shell raw material dispersion 3 was added dropwise over 1 hour while stirring in a water bath at 80 占 폚. The dropwise addition was continued for 5 hours while stirring was continued for 20 hours After that, a dispersion of insulating coating particles was obtained.

2.5 mass% Core particle 1 aqueous solution 200 g

2 g of dodecylbenzenesulfonic acid Na

2 g of dodecylbenzenesulfonic acid

[Shell raw material dispersion 3]

7.3 g of methyltrimethoxysilane

6.4 g of dimethyldimethoxysilane

1.3 g of tetramethoxysilane

0.1 g of dodecylbenzenesulfonic acid Na

Water 20 g

The resulting dispersion of the particles was centrifuged and redispersion in methanol was repeated several times and then observed by SEM. The average particle diameter was 315 nm and the coefficient of variation (C.V.) of the particle diameter was 5%. The moisture absorption rate was calculated to be 0.7% by mass. The eluted ammonium ion concentration was measured to be 30 ppm.

Further, the silicone oligomer 1 was added to the dispersion of the insulating coating particles in an amount equivalent to the particle weight, and the mixture was stirred for 2 hours to obtain an insulating coating particle 5 whose surface was subjected to silicone oligomer treatment. Thereafter, centrifugal separation was performed three times, and the particles were washed and dispersed in methanol.

(Fabrication of Insulating Coating Particles 6)

A dispersion of insulating coating particles was prepared in the same manner as in Synthesis of Insulating Coating Particles 4 except that the amount of the shell raw material dispersion 2 was 2 times the amount added over 2 hours. As a result of observation by SEM, the average particle diameter was 365 nm and the coefficient of variation (C.V.) of the particle diameter was 4.8%. The moisture absorption rate was calculated to be 1.0% by mass. The eluted ammonium ion concentration was measured to be 40 ppm.

Further, the silicone oligomer 1 was added to the dispersion of the insulating coating particles in an amount equivalent to the particle weight, and the mixture was stirred for 2 hours to obtain an insulating coating particle 6 whose surface was subjected to a silicone oligomer treatment. Thereafter, centrifugal separation was performed three times, and the particles were washed and dispersed in methanol.

(Preparation of Insulating Coating Particles 7)

Except that core particles 2 were used in place of core particles 1 in the synthesis of insulating coating particles 4 and three times the amount of the shell raw material dispersion 2 was added over 3 hours to prepare a dispersion of insulating coating particles Respectively. SEM observation revealed that the average particle diameter was 316 nm and the coefficient of variation (C.V.) of the particle diameter was 3.5%. The moisture absorption rate was calculated to be 1.2% by mass. The eluted ammonium ion concentration was measured to be 20 ppm.

Further, the silicone oligomer 1 was added to the dispersion of the insulating coating particles in an amount equivalent to the particle weight, and the mixture was stirred for 2 hours to obtain an insulating coating particle 7 whose surface was subjected to a silicone oligomer treatment. Thereafter, centrifugal separation was performed three times, and the particles were washed and dispersed in methanol.

(Fabrication of Insulating Coating Particles 8)

A dispersion of insulating coating particles was prepared in the same manner as in the synthesis of insulating coating particles 1 except that core particles 2 were used. As observed by SEM, the average particle diameter was 152 nm and the coefficient of variation (C.V.) of the particle diameter was 4.8%. The moisture absorption rate was calculated to be 1.0% by mass. The eluted ammonium ion concentration was measured to be 18 ppm.

The silicone oligomer 1 was added to the dispersion of the insulating coating particles in an amount equivalent to the particle weight, and the mixture was stirred for 2 hours to obtain an insulating coating particle 8 whose surface was subjected to silicone oligomer treatment. Thereafter, centrifugal separation was performed three times, and the particles were washed and dispersed in methanol.

(Preparation of Insulating Coating Particles 9)

A dispersion of insulating coating particles was prepared in the same manner as in the synthesis of insulating coating particles 1 except that the core particles 4 were used instead of the core particles 1. As observed by SEM, the average particle diameter was 405 nm and the coefficient of variation (C.V.) of the particle diameter was 5.0%. The moisture absorption rate was calculated to be 1.2% by mass. The eluted ammonium ion concentration was measured to be 22 ppm.

Further, the silicone oligomer 1 was added to the dispersion of the insulating coating particles in an amount equivalent to the particle weight, and the mixture was stirred for 2 hours to obtain an insulating coating particle 9 having a surface subjected to a silicone oligomer treatment. Thereafter, centrifugal separation was performed three times, and the particles were washed and dispersed in methanol.

(Preparation of Insulating Coating Particles 10)

Core particle 1 was used as insulating coating particle 10. The moisture absorption rate was calculated to be 0.5% by mass. The eluted ammonium ion concentration was measured to be 30 ppm.

(Production of insulating coating particles 11)

After the core particles 3 were prepared, the mixture of the following compounds was dropped into the dispersion of the core particles 3 obtained above for 1 hour, and the polymerization was further carried out for 4 hours to prepare insulating coating particles 11.

Styrene 40.4 g

1.6 g of divinylbenzene

VA-057 1.4 g

DMAEMAPS 0.6 g

When the particles were observed by SEM, the average particle diameter was 320 nm and the coefficient of variation (C.V.) of the particle diameter was 6%. The moisture absorption rate was calculated to be 1.0% by mass. The eluted ammonium ion concentration was measured to be 40 ppm.

(Preparation of Insulating Coating Particles 12)

A colloidal silica dispersion (concentration 20 mass%, manufactured by Fuso Chemical Co., Ltd., trade name: Quartron PL-13, average particle diameter 130 nm) was used as insulating coating particles 12. The moisture absorption rate was calculated to be 4.0% by mass. The eluted ammonium ion concentration was measured to be 12 ppm.

(Measurement of Thickness of Shell Layer)

The thicknesses of the shell layers were calculated from the average particle size before and after formation of the shells for the insulating covering particles 1 to 12. The results are shown in Table 2.

<Insulation Coating of Conductive Particles and Mounting Test of Anisotropic Conductive Film>

(Conductive particles)

A nickel layer having a thickness of 0.2 占 퐉 was formed by electroless plating on the surface of the crosslinked polystyrene particles having an average particle diameter of 3.0 占 퐉 and a palladium layer having a thickness of 0.04 占 퐉 was further formed on the outside of the nickel to obtain conductive particles.

(Insulation coating of conductive particles)

8 mmol of mercaptoacetic acid was dissolved in 200 mL of methanol to prepare a reaction solution. 10 g of conductive particles were added to the reaction solution, and the mixture was stirred at room temperature for 2 hours using a three-one motor and a stirring blade having a diameter of 45 mm, and the surface of the conductive particles was treated with mercaptoacetic acid. The conductive particles after the treatment were taken out by filtration using a membrane filter (manufactured by Millipore) having a diameter of 3 占 퐉 (pore diameter), and the extracted conductive particles were washed with methanol to obtain 1 g of conductive particles having carboxyl groups on the surface.

A 30% aqueous polyethyleneimine solution (Wako Pure Chemical Industries, Ltd.) having a molecular weight of 70000 was diluted with ultrapure water to obtain a 0.3 mass% aqueous solution of polyethyleneimine. 1 g of conductive particles having a carboxyl group on the surface obtained above was added to the aqueous solution of polyethyleneimine and the mixture was stirred at room temperature for 15 minutes. Subsequently, the conductive particles were taken out by filtration using a membrane filter (manufactured by Millipore Co., Ltd.) having a diameter of 3 μm, and the taken out conductive particles were added to 200 g of ultrapure water and stirred at room temperature for 5 minutes. Thereafter, the conductive particles were taken out by filtration using a 3 탆 membrane filter (manufactured by Millipore), and the conductive particles on the membrane filter were washed twice with 200 g of ultra-pure water to remove unadsorbed polyethyleneimine Respectively. By the above operation, conductive particles adsorbed on the surface of polyethyleneimine were obtained.

Subsequently, the conductive particles treated with polyethyleneimine were immersed in isopropyl alcohol, and the dispersions of the insulating coating particles 1 to 12 were respectively dropped to prepare insulating coated conductive particles having a fine particle coverage of 30%. The covering ratio was adjusted by a dropping amount.

Subsequently, the conductive particles were taken out by filtration using a membrane filter (manufactured by Millipore) having a diameter of 3 mu m, and the taken out conductive particles were placed in 200 g of ultrapure water and stirred at room temperature for 5 minutes. Thereafter, the conductive particles were taken out by filtration using a membrane filter of 3 탆 (manufactured by Millipore), and the conductive particles on the membrane filter were washed with 200 g of ultra-pure water twice, whereby the insulating coating particles were not adsorbed And the remaining conductive particles were removed. Subsequently, the insulating coated conductive particles were dried by heating at 80 DEG C for 30 minutes and then at 120 DEG C for 1 hour.

Subsequently, 10 g of the insulating coated conductive particles were placed in 100 g of the treating solution obtained by dissolving the silicone oligomer 2 (trade name: KR-212, manufactured by Shin-Etsu Chemical Co., Ltd.) in the same amount as the particle weight, . Thereafter, the particles were taken out by filtration, the insulated coated conductive particles taken out were washed with methanol and dried to obtain insulating coated conductive particles 1 to 12 having silicone oligomers 2 adhered on their surfaces.

(Solubility Test of Insulating Coating Particles)

The obtained insulating coated conductive particles were immersed in a solution of toluene / ethyl acetate (mixing ratio: 50 parts by mass / 50 parts by mass) and ultrasonically irradiated (24 kHz) for 5 minutes. Thereafter, insulating coated conductive particles were identified by SEM, And it was confirmed whether or not the dosing particles were peeled off. A is the case where there is no change in the adsorption amount of the insulating coating particles, and C is the case where the insulating coating particles are partially peeled off. The results are shown in Table 3.

(Fabrication of anisotropic conductive film and circuit connection using the same)

100 g of a phenoxy resin (trade name: PKHC, manufactured by Union Carbide Co., Ltd.) and 100 g of an acrylic rubber (40 parts by mass of butyl acrylate, 30 parts by mass of ethyl acrylate, 30 parts by mass of acrylonitrile and 3 parts by mass of glycidyl methacrylate 75 g) was dissolved in 400 g of toluene / ethyl acetate (mixing ratio: 50 parts by mass / 50 parts by mass) to obtain a 30 mass% solution. To this solution, 300 g of a liquid epoxy resin (epoxy equivalent 185, product of Asahi Kasei Epoxy KK, trade name: Novacure HX-3941) containing a microcapsulated latent curing agent was added and stirred to prepare an adhesive solution .

The insulating coated conductive particles having a silicone oligomer adhered on its surface were dispersed in this adhesive solution. Its concentration was 9% by volume based on the amount of the adhesive solution. The resulting dispersion was applied to a separator (polyethylene terephthalate film having a thickness of 40 占 퐉) using a roll coater and dried by heating at 90 占 폚 for 10 minutes to form an anisotropic conductive film having a thickness of 25 占 퐉 as a separator .

Subsequently, using the prepared anisotropic conductive film, a chip (1.7 mm x 1.7 mm, thickness: 0.5 mu m) with gold bumps (area: 30 m x 90 m, space 12 m, height 15 m, Connection of a glass substrate (thickness: 0.7 mm) with an ITO circuit was connected in accordance with the following procedures i) to iii) to prepare connection structure samples (Examples 1 to 9 and Comparative Examples 1 to 3).

i) was stuck to the pressure of the anisotropic conductive adhesive film (2 mm × 19 mm) for 80 ℃ on a glass substrate attached ITO circuit, 0.98 MPa (10 kgf / cm 2).

ii) The separator was peeled off, and the bumps of the chip and the glass substrate with the ITO circuit were aligned.

iii) Heating and pressurization were carried out from the top of the chip under the conditions of 190 占 폚, 40 MPa (low-pressure mounting condition) for 10 seconds, and this connection was performed.

(Insulation resistance test and conduction resistance test)

Insulation resistance test and conduction resistance test were performed on the manufactured connection structure samples. It is important that the anisotropic conductive film has high insulation resistance between the chip electrodes and low conduction resistance between the chip electrode and the glass electrode. The insulation resistance between the chip electrodes of 10 samples was measured. The values after the reliability test (migration test) in which the insulation resistance was allowed to stand at the initial value and 1000 hours at a temperature of 60 占 폚, a humidity of 90%, and a voltage of 20 V were measured. In addition, the yield when the insulation resistance after the reliability test was 10 ⁹ Ω or more was used as a good product was calculated.

An average value of 14 samples was measured for the conduction resistance between the chip electrode and the glass electrode. The value of the continuity resistance was measured after a reliability test (hygroscopic heat resistance test) in which the initial resistance and the temperature were kept at 85 DEG C and 85% humidity for 1000 hours. The measurement results are shown in Table 3.

Table 4 shows the integration of the results of the insulation resistance test and the continuity resistance test in Table 3. As a conduction resistance evaluation, A was defined as a conduction resistance of 1 Ω or less before the reliability test, B was defined as 1 Ω or more and 5 Ω or less, and C was defined as 5 Ω or more. As an evaluation of insulation reliability, A was defined as A when the yield before the reliability test was 80% or more, B was defined as 80% or more, 50% or less, and C as less than 50%. In addition, as the evaluation of the connection reliability, A was defined as a conduction resistance after the reliability test of 0 Ω or more and less than 50 Ω, B was defined as 50 Ω or more and less than 100 Ω, and C was defined as 100 Ω or more.

As shown in Table 3, the connection structure samples of Examples 1 to 9 exhibited good conduction resistance, insulation reliability and connection reliability both before and after the reliability test. This is presumably because heat resistance and solvent resistance can be imparted to the particles by forming a shell layer of a silicone compound on the core particles. In Examples 1 to 9, the yield was maintained at 100% even after the reliability test.

In the case of using polymer particles having no core shell structure or particles containing the same polymer in the shell as insulation coating particles, initial conduction resistance was good, but insulation reliability and connection reliability were deteriorated (Comparative Example 1 And 2). This is because the solvent resistance of the polymer particles deteriorates, so that the insulating coating particles are peeled off during the resin kneading, resulting in low insulation reliability. In addition, since the polymer particles have low heat resistance and high thermal expansion coefficient, it is presumed that they have an influence on the connection reliability. Further, when silica particles were used as the insulating coating particles, the conductive resistance was high (Comparative Example 3). It is presumed that since the elastic modulus of the particles is high, deformation of the particles becomes difficult and conduction becomes difficult.

One… Insulating coating particles, 1a ... Core particles, 1b ... Shell layer, 2 ... Base particles, 2a ... Spherical core particles, 2b ... The layer of metal, 10 ... Insulation coated conductive particles, 20 ... Insulating binder resin, 20a ... Insulating binder resin cured product, 30 ... The first circuit member, 31 ... A circuit board (first circuit board), 31a ... The main surface of the first circuit board, 32 ... Circuit electrodes (first circuit electrodes), 40 ... A second circuit member, 41 ... Circuit board (second circuit board), 41a ... The main surface of the second circuit board, 42 ... Circuit electrodes (second circuit electrodes), 50 ... An anisotropic conductive film, 50a ... Connection, 100 ... Connection structure.

Claims (15)

An insulating coating particle for forming insulating coated conductive particles by coating base particles containing a metal having a conductive surface,
A core shell structure having core particles and a shell layer,
Wherein the core particles comprise an organic polymer,
Wherein the shell layer comprises a silicon compound having at least one unit selected from the group consisting of SiO _4/2 units, RSiO _3/2 units and R ₂ SiO _2/2 units, wherein R is a C 1-4 alkyl group An alkyl group having 6 to 24 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group and a? - (meth) acryloxypropyl group)
Wherein the shell layer has a functional group having bonding property to the base particle,
Wherein the functional group having bonding property to the base particle is an epoxy group or a glycidyl group. The insulating coating particle according to claim 1, wherein the shell layer is treated with a silicone oligomer having an epoxy group or a glycidyl group. The insulating coating particle according to claim 1, wherein the shell layer has a thickness of 1 to 150 nm. The insulating coating particle according to any one of claims 1 to 3, wherein the shell layer is made of a silicon compound having only SiO _4/2 units, and the thickness of the shell layer is 1 to 50 nm. The insulating coating particle according to any one of claims 1 to 3, wherein the average particle diameter is 10 nm or more and 1 占 퐉 or less and the coefficient of variation of particle diameter is 3.5% or more and 10% or less. The insulating coating particle according to any one of claims 1 to 3, wherein the moisture absorption rate is 0.7% by mass or more and 5% by mass or less. The insulating coating particle according to any one of claims 1 to 3, wherein the eluted ammonium ion concentration is 15 ppm or more and 100 ppm or less. The insulating coating particle according to any one of claims 1 to 3, wherein the shell layer is formed by a reaction with a tertiary amine or a sulfonic acid compound as a catalyst. The insulating coating particle according to any one of claims 1 to 3, wherein the surface of the core particle has an amino group or a carboxyl group. The insulating coating particle according to any one of claims 1 to 3, wherein the core particle has a functional group having a pionic function. An insulating coated conductive particle comprising the insulating covering particles according to any one of claims 1 to 3 and base particles at least a part of which is covered with the insulating covering particles. An anisotropic conductive material comprising an insulating binder resin and the insulating coated conductive particle according to claim 11 dispersed in the insulating binder resin. A pair of opposing circuit members,
A connection including a cured product of the anisotropic conductive material according to claim 12 and connecting portions for bonding the circuit members to each other so that the circuit electrodes of the respective circuit members are electrically connected to each other through the pair of circuit members Structure. delete delete

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