TWI591654B - Insulation coating particles, insulating coated conductive particles, anisotropic conductive materials, and connection structures - Google Patents

Description

Insulation coating particles, insulating coated conductive particles, anisotropic conductive materials, and connection structures

The present invention relates to an insulating coating particle, an insulating coated conductive particle, an anisotropic conductive material, and a bonded structure.

It is known that by coating a part of the surface of the substrate particles with a resin, properties such as heat resistance, abrasion resistance, insulation, electrical conductivity, water repellency, adhesion, dispersibility, gloss, and coloring can be imparted to the substrate particles. The particles coated as described above can be used as a film, a binder, an adhesive, a paint, or the like as various fillers or modifiers.

As one type of coated particles, an insulating coated conductive particle in which a surface of a conductive particle having a metal surface is coated with an insulating resin is known. Further, in the anisotropic conductive film and the anisotropic conductive adhesive prepared by dispersing the insulating coated conductive particles in the adhesive, the conduction between the adjacent conductive particles can be prevented by the insulating resin for coating. The improvement in connection reliability is expected.

An insulating coated conductive particle in which an insulating layer is formed on a surface of a conductive particle by hybridization is disclosed in Japanese Laid-Open Patent Publication No. Hei 07-105716. Further, for example, Japanese Laid-Open Patent Publication No. 2003-26813 discloses an insulating coated conductive material in which a surface of a conductive particle is coated with an insulating coating particle having a particle diameter smaller than that of a conductive particle and having a different charge and a conductive particle. particle. When the surface of the conductive particles is coated with the particles for insulating coating, polymer particles or cerium oxide particles are mainly used.

Further, a particle which is insulated and coated with hollow particles is disclosed in Japanese Laid-Open Patent Publication No. 2005-203319. Further, a coated conductive particle coated with core-shell particles is disclosed in Japanese Laid-Open Patent Publication No. 2005-149764.

When polymer particles are used as the particles for insulating coating, even when the surface of the particles has a bonding functional group, the surface of the particles is dissolved in a solvent during resin kneading, and the particles for insulating coating are easily self-contained from the surface of the conductive particles. Peeling, so insulation reliability is likely to decrease. Further, since the polymer particles have low heat resistance and a large thermal expansion coefficient, the connection reliability tends to be unsatisfactory.

On the other hand, when the cerium oxide particles are used as the particles for insulating coating, they become highly elastic and are less likely to be deformed, so that the insulating properties are good. Further, the cerium oxide particles are characterized by high solvent resistance. However, when an anisotropic conductive film is formed and mounted at a low voltage, the conductivity tends to be low. Anthrone particles can be considered as a substitute for the cerium oxide particles, but they are not used because of the problem of monodispersity of the particle diameter.

In addition, the insulating-coated particles of JP-A-2005-203319 are likely to cause conduction inhibition caused by bubbles remaining in the particles, and absorb the solvent and other compounds formulated in the resin, so that hardening sometimes occurs. Obstruction.

In addition, since the particles for insulating coating used in the coated conductive particles of JP-A-2005-149764 are polymer particles, the solvent resistance is low similarly to the above-described polymer particles, and the coated conductive particles are made different. When the conductive film is mounted, there is a tendency that peeling occurs and insulation properties are lowered.

In view of the above, an object of the present invention is to provide an insulating coating particle and an insulating coated conductive particle including the same, which is useful when an anisotropic conductive material is obtained, that is, it can be oriented with high reliability. The electrodes of the disposed circuit members are electrically connected to each other, and can reliably prevent an electrically conductive anisotropic conductive material between adjacent electrodes that should ensure insulation. Further, an object of the present invention is to provide an anisotropic conductive material including the above-described insulating coated conductive particles, and a connection structure in which circuit members are connected to each other using the anisotropic conductive material.

In the present invention, it is found that the particles for insulating coating having the following structure are useful as particles for covering the substrate particles, and the structure includes core particles containing an organic polymer and a shell layer containing an anthrone-based compound.

In other words, the present invention provides an insulating coating particle comprising a substrate particle containing a conductive metal to form an insulating coated conductive particle, and the insulating coating particle has a core-shell structure having a core particle and a shell layer. The core particles contain an organic polymer, and the shell layer contains an anthrone-based compound having a group selected from the group consisting of SiO _4/2 units, RSiO _3/2 units, and R ₂ SiO _2/2 units. At least 1 unit. Here, R represents a group 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 γ-(meth)acryloxypropyl group. At least one of them. In the present specification, the term "anthrone-based compound" means a name including silicone and silica.

The insulating coating particles can be used for coating the surface of the conductive particles. borrow In this case, it is useful to obtain an anisotropic conductive material that can electrically connect the electrodes of the circuit members that are disposed opposite each other with high reliability, and can reliably prevent conduction between adjacent electrodes that should ensure insulation. Anisotropic conductive material. Further, by forming the ceria film or the fluorenone film as a shell layer, solvent resistance and heat resistance can be imparted.

When the ceria film is formed as the shell layer, even when the laminate is mounted at a low pressure, the shell layer is broken, so that the conductivity is improved. Further, in the direction different from the direction of being compressed at the time of mounting, the appearance shows elasticity, so that high insulation can be obtained. Further, since cerium oxide can be surface-treated, it can be blended with a binder resin to be described later to improve the dispersibility of the particles.

When the fluorenone film is formed as the shell layer, the particles for insulating coating are easily deformed even at the time of low compression, and thus the conductivity is improved. Further, by the properties of the anthrone, the dispersibility of the insulating coated conductive particles with respect to the resin is improved, and the hygroscopicity can also be lowered.

The shell layer preferably contains a functional group having a bonding property to the substrate particles. Since the shell layer has a bonding functional group, the insulating coating particles can uniformly form a covalent bond with respect to the substrate particles, and the adhesion between the shell layer and the substrate particles is improved.

When the "functional group having a bonding property to the substrate particles" is an epoxy group or a glycidyl group, the particles for insulating coating can easily form a covalent bond with respect to the substrate particles to which an amine group or the like is imparted. Bonding is preferred.

Further, the shell layer is preferably treated by an anthrone oligosaccharide having an epoxy group or a glycidyl group. By surface-treating the shell layer using an anthrone ketone oligomer having an epoxy group or a glycidyl group, the substrate pellet can be lifted The ease of adsorption and adhesion of the child. Such surface treatment is particularly preferred where the shell layer does not have surface functional groups.

In addition, the thickness of the shell layer is preferably from 1 nm to 150 nm. In this case, the on-resistance between the circuits in which the insulating-coated conductive particles coated with the insulating coating particles of the present invention are connected is further improved.

Further, the insulating coating particles of the present invention may be such that the shell layer contains an anthrone-based compound having only SiO _4/2 units, and the thickness of the shell layer is from 1 nm to 50 nm. In this case, the characteristics of the core particles can be exhibited.

In addition, the particles for insulating coating of the present invention preferably have an average particle diameter of 1 μm or less and a coefficient of variation (C.V.) of the particle diameter of 10% or less. When the average particle diameter is 1 μm or less, when the pressure-contacting of the anisotropic conductive material prepared by using the insulating coated conductive particles coated with the insulating coating particles of the present invention, the electrical conductivity and the insulating property can be coexisted. In addition, by setting the coefficient of variation (C.V.) of the particle diameter of the conductive particles to 10% or less, the reproducibility of the insulating properties can be improved.

Further, the particles for insulating coating of the present invention preferably have a moisture absorption rate of 5% by mass or less. Thereby, it is possible to suppress a short circuit due to ion migration or the like.

Further, the particles for insulating coating of the present invention preferably have a dissolved ammonium ion concentration of 100 ppm or less. Thereby, it is possible to suppress the occurrence of hardening inhibition in the anisotropic conductive material prepared by using the insulating coated conductive particles coated with the insulating coating particles of the present invention.

Further, the shell layer is preferably formed by a reaction in which a tertiary amine or a sulfonic acid compound is used as a catalyst.

Further, it is preferred that the surface of the core particle has an amine group or a carboxyl group. With this, When the shell layer is formed, the shell layer is easily formed on the surface of the core particle by hydrogen bonding by the hydrolyzed sterol group.

Further, the core particle is preferably a functional group having a diionic character. Thereby, elution of counter ions can be prevented.

Moreover, the present invention provides an insulating coated conductive particle comprising: the insulating coating particle and the substrate particle coated with at least a part of the surface by the insulating coating particle. Further, the present invention provides an anisotropic conductive material comprising: an insulating binder resin; and the above-mentioned insulating coated conductive particles dispersed in an insulating binder resin. According to such an insulating coating of the conductive particles or the anisotropic conductive material, the electrodes of the circuit members arranged to face each other can be electrically connected to each other with high reliability, and the conduction between adjacent electrodes to ensure insulation can be sufficiently prevented.

Further, the present invention provides a connection structure including: a pair of circuit members disposed opposite to each other; and a connection portion including a cured product of the anisotropic conductive material and interposed between a pair of circuit members, and The circuit members are connected to each other in such a manner that the circuit electrodes of the respective circuit members are electrically connected to each other. Since the connection structure includes the cured product of the anisotropic conductive material of the present invention in the connection portion, the electrodes of the circuit member can be electrically connected to each other with high reliability, and the adjacent electrodes between the adjacent electrodes to ensure insulation can be sufficiently prevented. Conductive.

According to the present invention, it is possible to provide an insulating coating particle and an insulating coating conductive particle including the same, which is useful when an anisotropic conductive material is obtained, that is, a circuit member which can be disposed to face each other with high reliability The electrodes are electrically connected to each other and can be surely prevented from being ensured Conductive anisotropic conductive material between adjacent electrodes of the edge. Moreover, the present invention can provide an anisotropic conductive material including the above-described insulating coated conductive particles, and a connection structure in which the circuit members are connected to each other using the anisotropic conductive material. In other words, according to the present invention, it is possible to perform an electrically conductive connection in which the on-resistance between the substrates, the insulation reliability, and the connection reliability are good, and it is possible to prevent leakage between adjacent particles.

Suitable 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 substrate particles 2 to constitute the insulating coated conductive particles 10. Hereinafter, each configuration will be described.

<Insulation coating particles> [core shell structure]

As shown in FIG. 1, the insulating coating particle 1 has a core-shell structure including a core particle 1a and a shell layer 1b formed on the surface of the core particle 1a. As a material of the core particle 1a and the shell layer 1b, the core particle 1a contains an organic polymer, and the shell layer 1b contains an anthrone-based compound. Since the thermal characteristics of the insulating coating particles 1 can be adjusted by appropriately selecting the type of the material constituting the core particles 1a and the shell layer 1b, the particles are easily deformed, and the conductivity is improved when the substrates are pressure-bonded. Further, the materials of the core particles 1a and the shell layer 1b may be appropriately selected in accordance with thermal properties, optical properties, mechanical properties, and the like as needed.

[nuclear particle]

The core particles are insulating particles containing an organic polymer. As organic high The molecule is not particularly limited as long as it has insulating properties, and for example, a resin used in the substrate particles described later may be used.

The polymerizable monomer which can be used for the production of the core particles includes the following non-crosslinkable monomer and crosslinkable monomer.

Specific examples of the non-crosslinkable monomer include: i) styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, and o-ethyl styrene. , m-ethyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, p-n-butyl styrene, p-tert-butyl styrene, p-n-hexyl styrene, p-octyl styrene , n-decyl styrene, p-nonyl styrene, p-dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p-chlorostyrene, 3,4-dichlorostyrene, etc. Styrene, (ii) methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, dodecyl acrylate , lauryl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloro acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylic acid N-butyl ester, isobutyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, methyl (meth) acrylates such as n-octyl acrylate, lauryl methacrylate, lauryl methacrylate, stearyl methacrylate, (iii) vinyl acetate, vinyl propionate, vinyl benzoate Vinyl esters such as esters and vinyl butyrate, (iv) N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylfluorene, and N-vinylpyrrolidone, (v Fluorine, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, trifluoroethyl acrylate, tetrafluoropropyl acrylate, etc. containing fluorinated alkyl (meth) 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; (poly)ethylene glycol di(meth)acrylate; (poly)alkylene glycol di(meth)acrylate such as propylene glycol di(meth)acrylate, (poly)-butanediol di(meth)acrylate; 1,6-hexanediol di(a) Acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-nonanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2,4-diethyl-1,5-pentyl Diol (meth) acrylate, butyl ethyl propylene glycol di (meth) acrylate, 3-methyl-1,7-octanediol di(meth) acrylate, 2-methyl-1, An alkanediol di(meth)acrylate such as 8-octanediol di(meth)acrylate; neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, Tetramethylol methane tri(meth)acrylate, tetramethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylation Cyclohexane dimethanol di(meth) acrylate, ethoxylated bisphenol A di(meth) acrylate, tricyclodecane dimethanol di(meth) acrylate, propoxylated ethoxylation Bisphenol A di(meth)acrylate, 1,1,1-trishydroxymethylethane di(meth)acrylate, 1,1,1-trishydroxymethylethane tri(meth)acrylate 1,1,1-trimethylolpropane triacrylate, diallyl phthalate and isomers thereof, and triallyl isocyanurate and derivatives thereof.

Further, a monomer having a mercapto group can also be used as the crosslinkable monomer, and specific examples thereof include γ-methacryloxypropyltrimethoxydecane and γ-methylpropenyloxypropyl group. Triethoxy decane, γ-methyl propylene methoxypropyl Methyldimethoxydecane, γ-methylpropenyloxypropylmethyldiethoxydecane, γ-acryloxypropylmethyldimethoxydecane, γ-methylpropenyloxy Propyl bis(trimethoxy)methylnonane, 11-methylpropenyloxyundecyltrimethoxydecane, vinyltriethoxydecane, 4-vinyltetramethylenetrimethoxydecane , 8-vinyl octamethylene trimethoxy decane, 3-trimethoxydecyl propyl vinyl ether, vinyl triethoxy decyl decane, p-trimethoxydecyl styrene, p-triethoxy Mercaptostyrene, p-trimethoxydecyl-α-methylstyrene, p-triethoxyindolyl-α-methylstyrene, γ-acryloxypropyltrimethoxydecane, vinyl trimethyl Oxydecane and N-β-(N-vinylbenzylaminoethyl-γ-aminopropyl)trimethoxydecane. Hydrochloride.

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

The method for producing the core particles can be a conventionally known method, and is not particularly limited. For example, an emulsion polymerization method, a phase transfer emulsion polymerization, a soap-free emulsion polymerization method, a microsuspension polymerization method, a miniemulsion polymerization method, a dispersion polymerization method, or the like can be used. A well-known method. Among them, from the viewpoint of easy control of the particle diameter and also suitable for industrial production, it is preferably produced by an emulsion polymerization method or a soap-free emulsion polymerization method. Further, the above-mentioned core particles can also be used commercially.

When the core particles are produced, the content of the polymerizable monomer in the reaction solution is preferably from 1% by mass to 50% by mass, more preferably from 2% by mass to 30% by mass, and even more preferably from 3% by mass to 30% by mass, based on the total amount of the reaction solution. The mass %~20% by mass, preferably 3% by mass to 15% by mass. When the crosslinked spherical polymer microparticles are produced, as in the prior method, even if the amount of the monomer in the reaction system is increased, the aggregate of the particles does not increase extremely, but if the content of the raw material monomer is 50% by mass. In the following, it is easy to obtain crosslinked spherical polymer microparticles in a high yield in a state in which the particles are monodispersed. On the other hand, when the content of the raw material monomer is 1% by mass or more, it does not require a long time until completion of the reaction, and it is practical from the viewpoint of industry.

The reaction temperature at the time of polymerization also varies depending on the type of the solvent to be used, and it is not always possible, but it is usually about 10 ° C to 200 ° C, preferably 30 ° C to 130 ° C, more preferably 40 ° C to 90 ° C. In addition, the reaction time is not particularly limited as long as it is a time required for the intended reaction to be substantially completed, and it is affected by the type of the monomer, the amount of the compound, the type of the functional group, the viscosity and concentration of the solution, and the target particle diameter. Big. For example, the reaction time at a reaction temperature of 40 ° C to 90 ° C is preferably from 1 hour to 72 hours, more preferably from 2 hours to 24 hours.

The core particles are easy to form a shell layer around them by having a carboxyl group, an amine group or both on the surface. The reason for this is that the hydrolyzed anthrone compound is easily adsorbed on the core particles by electrostatic interaction and hydrogen bonding. From this point of view, a functional group having a diionic property is particularly preferred. When introducing the functional groups to the core particles, it is preferred to use a monomer or initiator containing a carboxyl group or an amine group. Further, in order to improve the dispersibility of the particles, it is preferred 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. a mono-C1 to C8 alkyl ester of itaconic acid such as monobutyl acrylate; a mono C1 to C8 alkyl maleate such as maleic acid monobutyl ester; a vinyl-containing aromatic carboxylic acid such as vinyl benzoic acid Various kinds of acids a monomer having a carboxyl group, and a salt thereof. In addition, these compounds may be used alone or in combination of two or more, and may have a counter ion such as Na by neutralization.

Specific examples of the monomer having an amine group include aminoethyl acrylate, N-propylaminoethyl acrylate, N-ethylaminopropyl (meth)acrylate, and (meth)acrylic acid. -N-anilinoethyl ester, (meth)acrylic acid-N-cyclohexylaminoethyl ester, etc. Amine group-containing alkyl (meth)acrylate derivative, allylamine, N-methylallyl An allylamine derivative such as an amine, a triazine derivative such as an amino group-containing styrene derivative such as an aminostyrene or a 2-vinyl-4,6-diamino-s-triazine or the like A 1,3-propane sultone adduct of dimethylaminoethyl methacrylate or the like. Among these, a compound having a primary amino group or a secondary amino group is preferred. In addition, these compounds may be used alone or in combination of two or more.

In addition, a quaternary ammonium salt can also be used. Specific examples of the monomer having a quaternary ammonium (salt) group include a tertiary amine such as a C1 to C12 alkyl chloride, a dialkyl sulfuric acid, a dialkyl carbonate, or a chlorotoluene. It is made up of four levels. Specific examples include 2-(meth)acryloxyethyltrimethylammonium chloride, 2-(methyl)acryloxyethyltrimethylammonium bromide, and (meth)acrylic acid.醯oxyethyltriethylammonium chloride, (meth)acryloxyethyl dimethyl benzyl ammonium chloride, (meth) propylene oxiranyl ethyl methyl morpholinyl ammonium chloride, etc. a (meth)acrylic acid alkyl ester quaternary ammonium salt, (meth)acryloylaminoethyltrimethylammonium chloride, (meth)acryloylaminoethyltrimethylammonium bromide, An alkyl group such as (meth)acryloylaminoethyltriethylammonium chloride or (meth)acryloylaminoethyldimethylbenzylammonium chloride Acrylamide quaternary ammonium salt, dimethyl diallyl ammonium methyl sulfate, trimethyl vinyl phenyl ammonium chloride, tetrabutyl ammonium (meth) acrylate, trimethyl benzyl Alkyl ammonium (meth) acrylate, 2-(methacryloxy)ethyl trimethyl ammonium dimethyl phosphate, and the like.

Further, as the diionic monomer, an acrylate having a sulfobetaine or a carboxyl betain base can be used, and specific examples thereof include a sulfobetaine (meth) acrylate and a sulfobetaine acrylamide. A sulfobetaine vinyl compound, a sulfobetaine epoxide, a carboxybetaine acrylate, a carboxybetaine acrylamide, a carboxybetaine vinyl compound, a carboxybetaine epoxide, or the like.

A sulfonic acid group-containing monomer for introducing a functional group having a sulfonic acid group can be used. Examples thereof include an enesulfonic acid such as ethylenesulfonic acid, vinylsulfonic acid or (meth)allylsulfonic acid, an aromatic sulfonic acid such as styrenesulfonic acid or α-methylstyrenesulfonic acid, and a C1 to C10 alkane. (meth)allyl sulfosuccinate, sulfopropyl (meth) acrylate, etc., sulfo C2 to C6 alkyl (meth) acrylate, methyl vinyl sulfonate, 2-hydroxyl -3-(Methyl)acryloxypropyl sulfonic acid, 2-(methyl)propenylamino-2,2-dimethylethanesulfonic acid, 3-(methyl)acryloxyloxy Sulfonic acid, 3-(methyl)propenyloxy-2-hydroxypropanesulfonic acid, 2-(methyl)propenylamine-2-methylpropanesulfonic acid, 3-(methyl)propenylamine-2 a sulfonic acid group-containing unsaturated ester such as hydroxypropanesulfonic acid or the like.

These monomers may be used alone 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 more preferably 0.1 mol% to 1 mol% in terms of improving monodispersity. % of ear to use.

In addition, the following initiators can also be used. For example, 2'-azobis{2-[N-(2-carboxyethyl)methylmercaptopropane, 2,2'-azobis[2-(phenylmercapto)propane] diphosphate Acid salt (VA-545, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2'-azobis{2-[N-(4-chlorophenyl)methylindenyl]propane} dihydrochloride (VA-546, and Manufactured by Wako Pure Chemical Industries, 2,2'-azobis{2-[N-(4-hydroxyphenyl)methanyl)propane} dihydrochloride (VA-548, manufactured by Wako Pure Chemical Industries, 2, 2) '-Azobis[2-(N-benzylformamido)propane]dihydrochloride (VA-552, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2'-azobis[2-(N-allyl (M-methyl)propane]dihydrochloride (VA-553, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2'-azobis(2-methylamidinopropane) dihydrochloride (V50, manufactured by Wako Pure Chemical Industries, Ltd.) , 2,2'-azobis{2-[N-(4-hydroxyethyl)methylindolyl]propane} dihydrochloride (VA-558, manufactured by Wako Pure Chemical Industries, Ltd.), 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-imidazoline) -2-yl)propane]dihydrochloride (VA-044, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2-azobis[2-(4,5,6,7-tetrahydro-1H-1,3- Diazin-2-yl)propane] dihydrochloride (VA-054, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2-azobis[2-(3,4,5,6-four Hydropyrimidin-2-yl)propane]dihydrochloride (VA-058, manufactured by Wako Pure Chemical Industries), 2,2-azobis[2-(5-hydroxy-3,4,5,6-tetrahydropyrimidine) 2-yl)propane]dihydrochloride (VA-059, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2- Propane}dihydrochloride (VA-060, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2-azobis[2-(2-imidazolin-2-yl)propane] (VA-061, manufactured by Wako Pure Chemical Industries, Ltd.) ), 2,2'-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 peroxodisulfate (manufactured by Wako Pure Chemical Industries, Ltd.). These may be used alone or in combination of two or more. Also, when not using When a polymerizable monomer having a particle active hydrogen group or a hydrophilic functional group is used, it is preferred to use a compound having an active hydrogen group or a hydrophilic functional group in the above initiator in terms of improving the dispersibility of the particles. When a radical polymerization initiator is used, the amount thereof is usually 0.01 mol% to 1 mol% based on the polymerizable monomer. The core particles are produced by the conventional radical polymerization method, whereby the monodispersity of the finally obtained insulating coating particles can be improved. The amine group or the carboxyl group can also be imparted by adsorbing the polymer dispersant or the surfactant on the core particles.

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

The glass transition temperature (Tg) of the core particles can be arbitrarily adjusted by selecting the polymerizable monomer to be used, and can be arbitrarily adjusted by copolymerizing two or more kinds of polymerizable monomers having different Tgs. For example, as the polymerizable monomer having a Tg or a softening point temperature of 60 ° C or less when used alone, isobutyl methacrylate or glycidyl methacrylate may, for example, be mentioned. Further, by copolymerizing styrene, methyl methacrylate or the like having a Tg of 60 ° C or higher and butyl acrylate or dicyl methacrylate having a Tg of less than 60 ° C at an appropriate ratio, the Tg can be changed to 60. Below °C. Further, examples of the resin having a Tg of 80 ° C or higher include styrene, α-methylstyrene, methyl methacrylate, and butyl methacrylate. Some of these One type may be used alone or two or more types may be used in combination. Further, in order to prevent elution of the core particles into the solvent, the amount of the crosslinkable monomer relative to the non-crosslinkable monomer is preferably less than 5 mol%.

[shell]

The shell layer contains an anthrone-based compound and has 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. The plurality of Rs may be the same or different from each other.

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

The raw material of the SiO _4/2 unit in the anthrone-based compound may, for example, be one or two selected from the group consisting of ruthenium tetrachloride, tetraalkoxy decane, water glass, and metal ruthenate. the above. Specific examples of the tetraalkoxydecane include tetramethoxynonane, tetraethoxysilane, tetrapropoxydecane, and condensates thereof. These may be used singly or in combination of two or more.

R in the RSiO _3/2 unit in the anthrone-based compound is an alkyl group selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a carbon number of 6 to 24, a vinyl group, and a γ-(meth) acrylonitrile group. At least one of the groups consisting of oxypropyl groups. Depending on the substrate, it is also possible to select a small amount of a vinyl group, a γ-(meth)acryloxypropyl group or an organic group having an SH group, and a large amount of an alkyl group or an aromatic group. Examples of the raw material of the RSiO _3/2 unit include methyltrimethoxydecane, methyltriethoxydecane, methyltripropoxydecane, ethyltrimethoxydecane, and ethyltriethoxydecane. Ethyltripropoxydecane, phenyltrimethoxydecane, phenyltriethoxydecane, phenyltripropoxydecane, γ-mercaptopropyltrimethoxydecane, γ-methylpropenyloxypropane The trimethoxy decane, the vinyltrimethoxy decane, the 3,3,3-trifluoropropyltrimethoxy decane, and the like may be used singly or in combination of two or more.

As a raw material of the R ₂ SiO _2/2 unit (R may be selected from the same group as R in the RSiO _3/2 unit) in the anthrone-based compound, for example, dimethyl dimethoxy decane, diphenyl Dimethoxy decane, methyl phenyl dimethoxy decane, dimethyl diethoxy decane, diphenyl diethoxy decane, methyl phenyl diethoxy decane, diethyl dimethyl Oxydecane, ethyl phenyl dimethoxy decane, diethyl diethoxy decane, ethyl phenyl diethoxy decane, etc., hexamethylcyclotrioxane (D3), octamethyl ring a cyclic compound such as tetraoxane (D4), decamethylcyclopentaoxane (D5), dodecamethylcyclohexaoxane (D6) or trimethyltriphenylcyclotrioxane, Examples thereof include a linear or branched organic oxirane, γ-mercaptopropylmethyldimethoxydecane, γ-methylpropenyloxypropylmethyldimethoxydecane, and a vinylmethyl group. Methoxydecane, 3,3,3-trifluoropropylmethyldimethoxydecane, and the like. These may be used singly or in combination of two or more.

In the present embodiment, when the particles are desired to have flexibility or the like, a small amount of R ₂ SiO _2/2 units may be mixed. The ratio of the R ₂ SiO _2/2 unit in the anthrone-based compound in the insulating coating particles is preferably 50% by mole or less, and more preferably 10% by mole or less based on the total amount of the anthrone-based compound. If the ratio of R ₂ SiO _2/2 units is 50 mole% or less, the final particle does not become too soft, and improve shape retention. Further, the lower limit of the ratio of the R ₂ SiO _2/2 unit in the anthrone-based compound is 0 mol%.

As the anthrone-based compound, a small amount of R ₃ SiO _1/2 unit can be used without departing from the effects of the present embodiment. The proportion of the R ₃ SiO _1/2 unit in the anthrone-based compound is preferably 50 mol% or less, more preferably 1 mol% or less. When the ratio of the R ₃ SiO _1/2 unit is 5 mol% or less, the final fluorenone-based fine particles are more excellent in heat resistance. Further, the lower limit of the ratio of the R ₃ SiO _1/2 unit in the anthrone-based compound is 0 mol%.

[Method for Producing Particles for Insulation Coating]

In the case of the insulating coating particles, for example, when the shell layer is an _anthrone , the raw material of the SiO _4/2 unit and the raw material of the RSiO _3/2 unit are added to the solvent containing the core particle and the shell forming catalyst in a single or continuous manner. Further, an emulsion obtained by emulsifying a mixture of a raw material of R ₂ SiO _2/2 unit and water in a line mixer or a homogenizer can obtain particles for insulating coating coated with an anthrone. Although the time is prolonged, when the stability and particle size distribution of the latex particles are emphasized, it is preferred to use a continuous addition. When the acid catalyst is added before the addition of the emulsion, and the addition is carried out immediately under the conditions of the hydrolysis and the condensation reaction, the particles for insulating coating are greatly grown with time, and the display is narrow as in normal seed polymerization. Particles for insulating coating of particle size distribution. Further, when a relatively short period of time of 30 minutes to 1 hour is continuously added, a relatively good productivity and a narrow particle size distribution can be coexisted.

The insulating coating particles having a shell layer of cerium oxide can be produced, for example, by adding a raw material of SiO _4/2 unit and water/alcohol in a single or continuous manner to a solvent containing a core particle and a shell forming catalyst. Or a homogeneous solution of alcohol.

In addition, when the particles for insulating coating of the present embodiment are used as an anisotropic conductive material, the lower limit of the particle diameter of the insulating coating particles is preferably 10 nm, and the upper limit is 1 μm, and a lower limit is preferable. It is 30 nm and the upper limit is 500 nm. When the particle diameter is 5 nm or more, the distance between the adjacent coated conductive particles is larger than the jumping distance of the electrons, and leakage does not easily occur. When the particle diameter is 1000 nm or less, the required pressure and heat can be reduced at the time of pressure bonding.

In addition, two or more kinds of particles for insulating coating having different particle diameters may be used in combination, because small particles enter the gap covered by the large particles for insulating coating, and the coating density can be increased. In this case, the particle diameter of the small particles for insulating coating is preferably 1/2 or less of the particle diameter of the large particles, and the number of the small particles is preferably 1/4 or less of the number of the large particles.

[bonding functional group]

In the coated conductive particles of the present embodiment, the shell layer is preferably a surface partially covering the substrate particles via a functional group having a bonding property to the substrate particles. In this case, the insulating coating particles are chemically bonded to the substrate particles, and the bonding force is stronger than the bonding using only the van der Waals force or the electrostatic force. When the coated conductive particles (insulating coated conductive particles) are used for an anisotropic conductive material, it is possible to prevent the insulating coating particles from being kneaded in a binder resin or the like. In the case where the particles are peeled off or the particles for insulating coating are peeled off by contact with the adjacent insulating coated conductive particles, leakage may occur. Further, since the chemical bonding is formed only between the substrate particles and the particles for insulating coating, and the particles for insulating coating are not bonded to each other, the substrate particles are covered with a single layer of particles for insulating coating. Therefore, when particles having the same particle diameter are used as the substrate particles and the particles for insulating coating, the particle diameter of the insulating coated conductive particles can be easily made uniform.

The functional group is not particularly limited as long as it is a group capable of covalent bonding, and examples thereof include a decyl group, a carboxyl group, an amine group, an ammonium group, a hydroxyl group, a carbonyl group, a thiol group, a sulfonic acid group, and a decyl group. The epoxy group, the glycidyl group and the like preferably have an epoxy group or a glycidyl group from the viewpoint of the speed of the reactivity. The functional group may be imparted by first mixing a decane compound having the above functional group when forming a shell, or by treating the surface of the shell layer with a surfactant or a polymer dispersant. Moreover, from the viewpoint of improving the adsorptivity to the conductive particles, it is preferred to treat the surface of the shell layer by oligomerizing the decane compound having the above functional group (an fluorenone oligomer).

[shell forming catalyst]

The shell-forming catalyst refers to a catalyst for a sol-gel reaction of a decane oxide, and an acid or a base can be used. Examples of the acid catalyst include sulfonic acids such as aliphatic sulfonic acid, aliphatic substituted benzenesulfonic acid, and aliphatic substituted naphthalenesulfonic acid, and inorganic acids such as sulfuric acid, hydrochloric acid, and nitric acid. Among these, from the viewpoint of excellent emulsion stability of the organosiloxane, an aliphatic substituted benzenesulfonic acid is preferred, and n-dodecylbenzenesulfonic acid is particularly preferred. As a base catalyst, specifically, Listed: methylamine, etheramine, ethylamine, trimethylamine, triethylamine, triethanolamine, N,N-diisopropylethylamine, piperidine, piperazine, morpholine, quinuclidine ring, 1,4-two Nitrobicyclo[2.2.2]octane (1,4-diazabicyclo[2.2.2]octane, DABCO), pyridine, 4-dimethylaminopyridine, ethylenediamine, Tetramethylethylenediamine (TMEDA) , hexamethylenediamine, aniline, catecholamine, phenethylamine, 1,8-bis(dimethylamino)naphthalene (proton sponge), amino acid, amantadine, spermidine , spermine (spermine) and so on. In particular, it is preferred to use a compound having a tertiary amino group, and particularly preferably triethylamine.

[Average particle size, coefficient of variation of particle size (C.V.) and thickness of shell layer]

The average particle diameter of the particles for insulating coating is an average value obtained by observing 100 particle diameters by a scanning electron microscope (SEM). The average particle diameter of the particles for insulating coating differs depending on the particle diameter of the substrate particles and the intended use of the insulating coated conductive particles, but is preferably 1 μm or less. Thereby, the physical properties of the substrate particles are less likely to be governed by the physical properties of the particles for insulating coating, and the effect of using the substrate particles can be easily obtained. More preferably, the lower limit of the particle diameter of the particles for insulating coating is 10 nm, and the upper limit is 1 μm.

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

C.V.={(standard deviation of particle size)/(average particle size)}×100(%)...(1)

C.V. is 10% or less, preferably for improving characteristics, and more preferably 7%. Next, the best is 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, it is easy to uniformly apply pressure when the substrates are pressed together. Can improve the conductive connection.

In the particles for insulating coating, the particle diameter of the core particles and the thickness of the shell layer are not particularly limited, but the thickness of the shell layer is preferably 1/100 or more, more preferably 1/50 or more, of the particle diameter of the core particles. In addition, when the shell layer only contains SiO _4/2 units, the thickness of the shell layer is preferably from 1 nm to 50 nm. When the thickness is 50 nm or less, the physical properties of the particles for insulating coating are less likely to be governed by the physical properties of the shell layer, and the particles for insulating coating are easily deformed, and the surface of the substrate particles is easily exposed. Therefore, when the conductive connection between the substrates is performed, it is difficult to generate between the electrodes. Poor conduction.

[dissolved ammonium ion concentration]

When ammonium ions are eluted from the particles for insulating coating, the curing agent in the anisotropic conductive material produced by insulating-coated conductive particles may be deactivated to cause hardening inhibition. Therefore, the concentration of the ammonium ions eluted from the particles for insulating coating is preferably 150 ppm or less, more preferably 100 ppm or less. The eluted ammonium ion concentration can be measured, for example, by dispersing 0.5 g of the insulating coating particles after drying in 25 g of ion-exchanged water, and placing it in a pressure-resistant container at 100 ° C for 12 hours, followed by ion chromatography. Method to determine.

[hygroscopic rate]

The moisture absorption rate of the particles for insulating coating is preferably 5% by mass or less. When the moisture absorption rate is 5% by mass or less, short-circuiting due to ion migration or the like can be suppressed. 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 is 60 ° C, humidity) After standing for 18 hours in 90%), the particle weight was measured again.

<Substrate particles>

The surface of the substrate particles contains a conductive metal and functions as a conductive particle. In this case, as shown in FIG. 1, the substrate particles 2 may be particles of a layer 2b having a conductive metal formed on the surface of the spherical core material particles 2a containing an inorganic compound or an organic compound to be described later. It is a metal particle containing only a metal having conductivity. In addition, since the particles of the conductive metal layer formed on the surface of the spherical core material particles containing the organic compound are deformed at the time of pressure bonding when the substrates are electrically connected to each other, the joint area is increased, so that the connection stability is obtained. Better words.

The conductive metal is not particularly limited, and examples thereof include gold, silver, copper, platinum, zinc, iron, tin, lead, aluminum, palladium, cobalt, indium, nickel, chromium, titanium, ruthenium, osmium, and iridium. Metals such as cadmium and metal compounds such as indium tin oxide (ITO) and solder.

When the metal layer containing the above-mentioned conductive metal is formed on the surface of the spherical core particle 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 laminate structure, it is preferred that the outermost layer contains gold, palladium or nickel. Since the outermost layer contains palladium or gold, the corrosion resistance is high and the contact resistance is also small, so that the obtained coated particles become more excellent coated particles.

The method of forming a conductive metal layer on the surface of the spherical core material particle containing the organic compound is not particularly limited, and examples thereof include a known method such as a physical metal vapor deposition method or a chemical electroless plating method, but the steps are as follows. In terms of simplicity, electroless plating is suitable. As no electricity Examples of the metal layer formed by the deplating method include gold, silver, copper, platinum, palladium, nickel, rhodium, iridium, cobalt, tin, and alloys thereof. However, as the substrate particles of the present embodiment, In order to form a uniform coating at a high density, it is preferred that a part or all of the metal layer be formed by electroless nickel plating.

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, plating, and sputtering.

The thickness of the metal layer is not particularly limited, but a preferred lower limit is 0.005 μm, and a preferred upper limit is 2 μm. When the thickness of the metal layer is less than 0.005 μm, a sufficient effect as a conductive layer may not be obtained. When the thickness of the metal layer exceeds 2 μm, there is a case where the specific gravity of the obtained insulating coated conductive particles becomes The hardness of the spherical core material particles which are too high or contains an organic compound has become a hardness which is not sufficiently deformable. A more preferable lower limit of the thickness of the metal layer is 0.01 μm, and a more preferable upper limit is 1 μm.

Further, when the outermost layer of the metal layer is a gold layer or a palladium layer, a preferred lower limit of the thickness of the gold layer or the palladium layer is 0.001 μm, and a preferred upper limit is 0.5 μm. When the thickness of the gold layer or the palladium layer is less than 0.001 μm, it is difficult to uniformly coat the metal layer, and the effect of improving the corrosion resistance or the contact resistance value cannot be expected. If the thickness of the gold layer or the palladium layer exceeds 0.5 μm, Although it has its effect, the price becomes higher. A more preferred lower limit of the thickness of the gold layer or the palladium layer is 0.01 μm, and a more preferred upper limit is 0.3 μm.

When the substrate particles are formed with the conductive metal layer on the surface of the spherical core particles, the spherical core particles are not particularly limited, and examples thereof include particles having a uniform composition and various raw materials. Particles of a layered multilayer structure, and the like. Among them, when various properties such as mechanical properties and electrical properties are to be imparted to the substrate particles, particles having a multilayer structure are suitable.

The material constituting the spherical core material particles is not particularly limited, and examples thereof include inorganic compounds such as known cerium oxide, organic compounds, and the like. When the insulating coated conductive particles are used for the anisotropic conductive material, the organic compound is preferable because the surface of the substrate particles and the electrode can be bonded by being deformed during pressure bonding when the substrates are electrically connected to each other. Excellent area and excellent connection stability.

The organic compound is not particularly limited, and examples thereof include polyolefins such as polyethylene, polypropylene, polystyrene, polypropylene, polyisobutylene, and polybutadiene, and acrylic resins such as polymethyl methacrylate and polymethyl acrylate. , polyester resin such as polyalkylene terephthalate, 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, (Non) saturated polyester resin, polyphenylene ether, polyacetal, polyfluorene, polycarbonate, polyamine, polyimine, polyamidimide, polyetheretherketone, polyether oxime, and the like. Among them, a resin obtained by polymerizing one or two or more kinds of polymerizable monomers having an ethylenically unsaturated group is preferred because it is easy to obtain an appropriate hardness.

Specific examples of the non-crosslinkable monomer include: i) styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, and o-ethyl styrene. , m-ethylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, pair N-hexyl styrene, p-octyl styrene, p-n-decyl styrene, p-n-decyl styrene, p-dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p-chlorobenzene Styrene such as ethylene or 3,4-dichlorostyrene, (ii) methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hexyl acrylate, 2-ethyl acrylate Ester, n-octyl acrylate, dodecyl acrylate, lauryl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloro acrylate, methyl methacrylate, methacrylic acid Ester, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, methacrylic acid a (meth) acrylate such as an ester, lauryl methacrylate or stearyl methacrylate; (iii) a vinyl ester such as vinyl acetate, vinyl propionate, vinyl benzoate or vinyl butyrate; (iv) N-vinylpyrrole, N-vinylcarbazole, N-vinyl anthracene, N-B N-vinyl compound such as pyrrolidone, (v) fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, trifluoroethyl acrylate, tetrafluoropropyl acrylate, etc. Acrylates, and (vi) conjugated dienes such as butadiene and isoprene.

Specific examples of the crosslinkable monomer include divinyl compounds such as divinylbenzene, divinylbiphenyl, and divinylnaphthalene; (poly)ethylene glycol di(meth)acrylate; (poly)alkylene glycol di(meth)acrylate such as propylene glycol di(meth)acrylate or (poly)butylene glycol di(meth)acrylate; 1,6-hexanediol di(methyl) Acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1 , 12-dodecanediol di(meth)acrylate, 3-methyl -1,5-pentanediol di(meth)acrylate, 2,4-diethyl-1,5-pentanediol di(meth)acrylate, butyl ethylpropylene glycol di(meth)acrylic acid Alkane diols such as ester, 3-methyl-1,7-octanediol di(meth) acrylate, 2-methyl-1,8-octanediol di(meth) acrylate Acrylate; neopentyl glycol di(meth) acrylate, trimethylolpropane tri(meth) acrylate, tetramethylol methane tri(meth) acrylate, tetramethylolpropane tetra (a) Acrylate, pentaerythritol tri(meth)acrylate, ethoxylated cyclohexanedimethanol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, tricyclodecane Dimethanol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, 1,1,1-trishydroxymethylethane di(meth)acrylate, 1 , 1,1-trimethylolethane tri(meth)acrylate, 1,1,1-trimethylolpropane triacrylate, diallyl phthalate and isomers thereof, and Triallyl cyanurate and its derivatives.

The above-mentioned monomer and other polymerizable monomers may be used singly or in combination of two or more kinds. As a method for producing such spherical core particles, a conventionally known method can be used, and is not particularly limited, and examples thereof include an emulsion polymerization method, a phase transfer emulsion polymerization, a suspension polymerization method, a dispersion polymerization method, and a seed polymerization method. Soap-free precipitation polymerization method, and the like. Among them, a seed polymerization method excellent in the controllability of the particle diameter is suitable. Further, the spherical core material particles may be used commercially.

<Insulation coated conductive particles>

The insulating-coated conductive particles of the present embodiment are obtained by coating the surface of the substrate particles with the particles for insulating coating. Here, the particles for insulating coating are preferably 20% or less of the surface area thereof and are bonded to the surface of the substrate particles. touch. When the surface area to be contacted is 20% or less, there is a tendency that the deformation of the insulating coating particles is small, the size of the obtained coated conductive particles becomes more uniform, and the shell layer is less likely to be broken, and the core shell is easily maintained. structure. In addition, the lower limit is not particularly limited, and when the insulating coating particles and the substrate particles are bonded by, for example, a polymer having a long chain length, they may be substantially 0%.

In the insulating-coated conductive particles of the present embodiment, it is preferable that 5% or more of the surface area of the substrate particles is coated with the insulating coating particles. When the surface area to be coated is 5% or more, it is easy to ensure insulation of the insulating coated conductive particles. Further, when the insulating coated conductive particles are used for the anisotropic conductive material, the preferred lower limit of the coverage of the insulating coating particles is 5%, and the preferred upper limit is 60%. When the coverage is 5% or more, it is possible to effectively prevent the metal surface of the adjacent substrate particles from coming into contact with each other and cause leakage in the lateral direction. When the coverage is 60% or less, it is easy to ensure sufficient conductivity. In addition, the coverage of the particles for insulating coating on the surface of the substrate particle can be increased by the amount (concentration) of the particles for insulating coating, the amount of the functional group (density) introduced to the surface of the substrate particle, and the type of the reaction solvent. Wait to control.

The coverage ratio of the particles for insulating coating on the surface of the substrate particle is a value calculated by the following formula (2).

Coverage ratio (%) = {(area of the portion of the surface of the substrate particle covered by the insulating coating particles) / (total surface area of the substrate particles)} × 100... (2)

The insulating coated conductive particles can be produced by dry mixing or wet heteroaggregation. From the viewpoint of the coverage ratio and the control of the distance between the particles, it is preferred to use wet heteroaggregation. As a method of utilizing wet heteroaggregation, a method of using covalent bonding or electrostatic attraction between particles can be utilized. In order to prevent the particles for insulating coating from falling off, it is preferred to use covalent bonding. The coverage ratio can be adjusted by appropriately adjusting the ratio of the conductive particles to the particles for insulating coating. In addition, when the formation of a covalent bond is slow, the formation of a covalent bond can be promoted by heating the solvent.

Specifically, chemical bonding can be formed by mixing particles for insulating coating (hereinafter sometimes referred to as "subparticles") into which a glycidyl group or an epoxy group is introduced, and conductive particles to which an amine group is added. Thereby, the insulating coated conductive particles are produced.

As a method of introducing an amine group into a conductive particle having a metal layer containing gold or palladium, there is the following method. The surface of the metal layer is treated with a compound having a mercapto group, a thio group or a disulfide group forming a coordination bond for gold or palladium, and a hydroxyl group, a carboxyl group, an alkoxy group or an alkoxycarbonyl group, whereby a hydroxyl group is selected from the group consisting of a hydroxyl group The functional groups in the carboxyl group, the alkoxy group and the alkoxycarbonyl group are introduced to the surface. Examples of the compound to be used include mercaptoacetic acid, 2-mercaptoethanol, methyl thioglycolate, mercapto succinic acid, thioglycerol, and cysteine.

The method for treating the surface of the metal layer by the above compound is not particularly limited, and a method of dispersing a compound such as thioglycolic acid in an organic solvent such as methanol or ethanol at a concentration of about 10 mmol/L to 100 mmol/L, and then Conductive particles having a metal surface are dispersed therein.

An official having a surface such as a hydroxyl group, a carboxyl group, an alkoxy group or an alkoxycarbonyl group The surface potential (zeta potential) of the energy-based particles is usually negative when the pH is in the neutral region. On the other hand, the surface potential of the inorganic oxide particles having a hydroxyl group is usually also negative. In many cases, it is difficult to sufficiently cover the surface of the particles whose surface potential is negative by the particles having a negative surface potential. However, by providing the polymer electrolyte layer therebetween, the particles for insulating coating can be efficiently attached to the conductive particles. on. In addition, since the insulating coating particles can be uniformly coated on the surface of the conductive particles without any defects by providing the polymer electrolyte layer, the insulating properties are ensured even when the circuit electrode spacing is narrow, and the sealing property is more remarkable. The effect of connecting the electrodes between the electrodes for electrical connection is low.

As the polymer electrolyte forming the polymer electrolyte layer, a polymer which is ionized in an aqueous solution and has a functional group having a charge in a main chain or a side chain can be used. Among them, a polycation is preferable. As the polycation, generally, a functional group having a positive charge such as a polyamine, such as Polyethylenimine (PEI), Poly Allylamine Hydrochloride (PAH), and poly 2 can be used. Allyldimethylammonium chloride (PDDA), polyvinylpyridine (PVP), polylysine, polypropylene decylamine, and at least one of these Copolymer. Among them, polyethyleneimine has a high charge density and a strong bonding force.

[Insulating coated fluorenone oligomer treatment of conductive particles]

When the particles for insulating coating have a sterol group on the surface thereof, the fluorenone coupling agent or the fluorenone oligomer obtained by oligomerizing the decane coupling agent is treated, whereby the insulation of the insulating coated conductive particles described later can be improved. reliable Sex. Further, in terms of easiness of reaction with the surface of the particles, it is preferred to use the above decane coupling agent in an oxime oxime oligomerization. The anthrone oligo is preferably subjected to three-dimensional crosslinking in advance by a condensation reaction. Further, the anthrone oligo is preferably a functional group having a hydrophobic group and an inorganic material such as ceria.

The fluorenone oligomer generally contains a siloxane unit having a structure represented by the following chemical formula.

In the formula, 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 or 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. Further, R ¹ and R ² may be the same or different from each other.

The degree of polymerization of the fluorenone oligomer is usually 3 or more, preferably 5 or more, more preferably 6 or more, still more preferably 10 or more. Further, the degree of polymerization of the fluorenone oligomer is usually 90 or less, preferably 80 or less, more preferably 70 or less, still more preferably 50 or less. When the degree of polymerization is increased, processing unevenness is less likely to occur during surface treatment, and reliability can be improved. Further, when the degree of polymerization is small, the fluorenone oligomer tends to adhere to a sufficient thickness.

The degree of polymerization of the fluorenone oligomer is based on gel permeation chromatography (Gel Permeation Chromatography (GPC) The weight average molecular weight in terms of the standard polystyrene obtained by the measurement was measured and calculated by the following formula (3).

Degree of polymerization = weight average molecular weight / molecular weight of a siloxane unit... (3)

Further, when a plurality of oxoxane units are contained in the fluorenone oligomer, the degree of polymerization is calculated from the average values of these.

The three-dimensionally crosslinked fluorenone oligomer is usually preferably a trifunctional fluorinated alkane unit represented by R ¹ SiO _3/2 and a tetrafunctional fluorene oxide represented by SiO _4/2 . At least one of the units. For example, the fluorenone oligomer may contain a difunctional siloxane unit represented by R ² SiO _2/2 and a tetrafunctional siloxane unit represented by SiO _4/2 , and may also contain A difunctional siloxane oxide unit represented by R ² SiO _2/2 and a trifunctional siloxane oxide unit represented by R ¹ SiO _3/2 .

The siloxane oxide oligomer is preferably a tetrafunctional fluorene oxide unit having 15 mol% or more, more preferably 20 mol% to 60 mol% tetrafunctional, based on all of the decane units. Sexual alkane unit.

The fluorenone oligomer can be synthesized, for example, by condensing chlorine or alkoxy decane corresponding to a desired oxoxane unit by an acid catalyst in the presence of water. The condensation reaction is carried out to such an extent that the fluorenone oligomer is not in a gel state until it is attached to the submicron polymer particles. Therefore, the reaction temperature, the reaction time, the composition ratio of the oligomer, and the type and amount of the catalyst were changed to adjust. As the catalyst, acetic acid, hydrochloric acid, maleic acid, phosphoric acid or the like can be preferably used.

The fluorenone oligomer is attached to the submicron polymer particles, and a part thereof is also attached to the conductive particles. The adhesion amount of the fluorenone oligomer in the entire insulating coated conductive particles is preferably 0.01% by mass to 10% by mass, and more preferably 0.05% by mass to 5.00% by mass based on the mass of the submicron polymer particles. When the amount of adhesion is 0.01% by mass or more, the effect of improving the adhesion of the interface tends to be easily obtained. When the amount of adhesion is 10% by mass or less, the deterioration of heat resistance can be prevented.

Such an insulating coated conductive particle can be used as a so-called anisotropic conductive material for electrically connecting a small motor component such as a semiconductor element to a substrate or electrically connecting the substrates to each other.

<Anisotropic conductive material>

The adhesive composition can be prepared by dispersing the insulating coated conductive particles in an insulating binder resin. Moreover, the adhesive composition can be used as an anisotropic conductive material (circuit connecting material). The anisotropic conductive material may also be formed into a film shape to be used as an anisotropic conductive film. The anisotropic conductive film 50 shown in FIG. 2 is formed by molding an adhesive composition into a film shape, and the adhesive composition is obtained by dispersing the insulating coated conductive particles 10 in an insulating adhesive resin 20.

<connection structure>

The connection structure 100 shown in FIG. 3 includes the first circuit member 30 and the second circuit member 40 that face each other, and a connection portion that connects the first circuit member 30 and the second circuit member 40 is provided between the first circuit member 30 and the second circuit member 40. 50a.

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

Specific examples of the circuit member include chip components such as an integrated circuit (IC) wafer (semiconductor wafer), a resistor wafer, a capacitor chip, and a driver IC, and a rigid type package substrate. The circuit components are provided with circuit electrodes and typically have a plurality of circuit electrodes. As another circuit member that connects the above-described circuit member, a wiring board such as a flexible tape substrate having metal wiring, a flexible printed wiring board, or a glass substrate on which indium tin oxide (ITO) is deposited may be used. By using the anisotropic conductive film 50, the circuit members can be connected to each other efficiently and with high connection reliability. Therefore, the anisotropic conductive film 50 is suitable for a chip on glass (COG) package and a chip on film on a wiring substrate of a wafer component including a plurality of fine connection terminals (circuit electrodes). Package.

The connecting portion 50a includes a cured product 20a of an insulating binder resin contained in the circuit connecting material, and 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 to each other via 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 and directly contact both the circuit electrode 32 and the circuit electrode 42. On the other hand, in the lateral direction of the drawing, the insulating coating particles 1 are interposed between the substrate particles 2, and the insulating property is maintained. Therefore, if the anisotropic conductive film 50 is used, a narrow pitch of about 10 μm can be improved. Insulation reliability.

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

As the epoxy resin, a bisphenol type epoxy resin derived from epichlorohydrin, bisphenol A, bisphenol F, bisphenol AD or the like can be used alone, and is derived from epichlorohydrin and phenol novolak or cresol novolac. The epoxy novolak resin, which has a naphthalene epoxy resin having a skeleton of a naphthalene ring, various rings having two or more glycidyl groups in one molecule such as glycidylamine, glycidyl ether, biphenyl or alicyclic An oxygen compound or the like may be used in combination of two or more kinds.

These epoxy resins are preferably high-purity products in which impurity ions (Na ⁺ , Cl ^{- ,} etc.), hydrolyzable chlorine, or the like are reduced to 300 ppm or less. Thereby, it is easy to prevent electromigration.

Examples of the latent curing agent include an imidazole-based, an anthraquinone-based, a boron trifluoride-amine complex, a phosphonium salt, an amine imine, a polyamine salt, and dicyandiamide. Further, a mixture of a radical-reactive resin and an organic peroxide or an energy ray-curable resin such as an ultraviolet ray may be used for the adhesive.

In the insulating binder resin 20, a butadiene rubber, an acrylic rubber, a styrene-butadiene rubber, an anthrone rubber or the like may be mixed in order to lower the stress after the adhesion or to improve the adhesion.

In order to make the adhesive composition into a film form, it is effective to blend a thermoplastic resin such as a phenoxy resin, a polyester resin, or a polyamide resin having film formability into the composition. These film-forming polymers also have an effect on stress relaxation during curing of the reactive resin. Especially for film forming polymer When a functional group such as a hydroxyl group is present, it is preferred because the adhesion is improved. The formation of the film can be carried out by dissolving or dispersing the subsequent composition containing the epoxy resin, the acrylic rubber, the latent curing agent, and the film-forming polymer in an organic solvent to thereby liquefy the film. Then, it is coated on a release substrate (spacer film), and the solvent is removed below the activation temperature of the hardener. The organic solvent to be used in this case is preferably an aromatic hydrocarbon-based or oxygen-containing mixed solvent from the viewpoint of improving the solubility of the material.

The thickness of the anisotropic conductive film 50 is relatively determined in consideration of the particle diameter of the insulating coated conductive particles and the characteristics of the adhesive composition, but is preferably 1 μm to 100 μm. When the thickness is less than 1 μm, sufficient adhesion cannot be obtained. When the thickness exceeds 100 μm, a large amount of insulating coated conductive particles are required in order to obtain conductivity, which is not realistic. For the above reasons, the thickness is preferably from 3 μm to 50 μm.

<Method of Manufacturing Connection Structure>

4(a) to 4(c) are process diagrams showing a procedure of manufacturing the above-described connection structure using an anisotropic conductive material in a schematic cross-sectional view. In the present embodiment, the anisotropic conductive material is thermally cured to produce a bonded structure.

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.

Next, the anisotropic conductive film 50 is placed on the surface of the first circuit member 30 on which the circuit electrode 32 is formed. Then, the anisotropic conductive film 50 is pressurized in the directions of the arrow A and the arrow B in FIG. 4(a), and the anisotropic conductive film 50 is temporarily connected to the first circuit member 30 (FIG. 4(b)). .

The pressure at this time is not particularly limited as long as it does not cause damage to the circuit member, and is usually preferably 0.1 MPa to 30.0 MPa. Further, it is also possible to pressurize while heating, and set the heating temperature to a temperature at which the anisotropic conductive film 50 does not substantially harden. The heating temperature is usually preferably set to 50 ° C to 190 ° C. The above heating and pressurization are preferably carried out in the range of 0.5 second to 120 seconds.

Then, as shown in FIG. 4( c ), the second circuit member 40 is placed on the anisotropic conductive film 50 such that the second circuit electrode 42 faces the side of the first circuit member 30 . Then, as the surface of the anisotropic conductive film 50 is heated, the whole is pressurized in the directions of the arrow A and the arrow B in Fig. 4(c).

The heating temperature at this time is a temperature at which the anisotropic conductive film 50 can be hardened. The heating temperature is preferably from 60 ° C to 200 ° C, more preferably from 70 ° C to 190 ° C, and even more preferably from 80 ° C to 160 ° C. When the heating temperature is less than 60 ° C, the curing rate tends to be slow. When the heating temperature exceeds 200 ° C, undesired side reactions tend to proceed easily. The heating time is preferably from 0.1 second to 180 seconds, more preferably from 0.5 second to 180 seconds, and still more preferably from 1 second to 180 seconds.

The connection portion 50a is formed by the hardening of the anisotropic conductive film 50, whereby the connection structure 100 shown in FIG. 3 is obtained. The conditions of the connection are appropriately selected depending on the intended use, the composition of the adhesive, and the circuit member. In addition, when the insulating adhesive resin 20 in the anisotropic conductive film 50 is cured by light, it is sufficient that the anisotropic conductive film 50 is appropriately irradiated with an actinic ray or an energy ray. Examples of the actinic ray include ultraviolet light, visible light, and infrared light. Examples of the energy rays include an electron beam, X-rays, γ-rays, and microwaves.

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

[Example]

Hereinafter, the contents of the present invention will be more specifically described by way of examples and comparative examples. Furthermore, the present invention is not limited to the following examples.

<Production of particles for insulating coating>

(production of nuclear particle 1)

The following compound was added in one portion to a 500 ml flask, and the dissolved oxygen was replaced with nitrogen for 1 hour, and then heated and stirred in a water bath at 70 ° C for about 6 hours to obtain core particles 1.

When the nuclear particle 1 was observed by SEM, the average particle diameter was 262 nm, and the coefficient of variation (C.V.) of the particle diameter was 4.1%.

(Preparation of nuclear particles 2 to nuclear particles 4)

The core particles 2 to 4 are produced in the same manner as the preparation procedure of the above-described core particle 1 except that the materials described in Table 1 are used. In Table 1, "KBE-503" represents γ-methacryloxypropyltriethoxydecane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name).

(Production of Insulation Coating Particle 1)

The following compound was added in one portion to a 500 ml flask, and the mixture was stirred while stirring in a water bath at a temperature of 35 ° C for 1 hour, and the mixture was stirred for 6 hours. A dispersion of particles for insulating coating.

[Shell raw material dispersion 1]

The dispersion of the obtained particles for insulating coating was centrifuged, and then redispersion in methanol was repeated a plurality of times. Then, the particles for insulating coating were observed by SEM, and as a result, the average particle diameter was 300 nm, and the coefficient of variation (C.V.) of the particle diameter was 4.2%. In addition, the obtained insulation coating After allowing the particles 1 g to stand in a high-temperature and high-humidity test cell (temperature: 60 ° C, humidity: 90%) for 18 hours, the particle weight was measured again to calculate the moisture absorption rate. The moisture absorption rate was 1.5% by mass. Further, after the obtained particles were dried, 0.5 g of the obtained particles were dispersed in 25 g of ion-exchanged water, and the mixture was allowed to stand at 100 ° C for 12 hours in a pressure-resistant container, and then the eluted ammonium was determined by ion chromatography. The ion concentration was 15 ppm.

Then, 60 g of γ-glycidoxypropyltrimethoxydecane, 3 g of methanol, 14 g of water, and hydrochloric acid (1 mass% of the total amount) were mixed, and stirred at 60 ° C for 4 hours, whereby the synthesis was shrunk. Glyceryl fluorenone oligomer 1. The fluorenone oligo polymer 1 having the same weight as the weight of the particles was added to the dispersion liquid of the insulating coating particles and stirred for 2 hours to obtain the insulating coating particles 1 having a surface treated with an fluorenone oligomer. Thereafter, the mixture was centrifuged three times, and after washing the particles, they were dispersed in methanol.

(Production of Insulation Coating Particles 2)

In the synthesis of the particles for the insulating coating, the dispersion of the particles for insulating coating was prepared in the same manner except that the amount of the tetraethoxy decane in the shell raw material dispersion was doubled. Observation by SEM revealed an average particle diameter of 325 nm and a coefficient of variation (C.V.) of the particle diameter of 4.0%. The moisture absorption rate was calculated and found to be 2.0% by mass. The eluted ammonium ion concentration was measured and found to be 31 ppm.

In addition, the fluorenone oligomer 1 having the same weight as the weight of the particles was added to the dispersion liquid of the insulating coating particles and stirred for 2 hours to obtain the insulating coating particles 2 treated with the fluorenone oligomer. Thereafter, the mixture was centrifuged three times, and after washing the particles, they were dispersed in methanol.

(Production of Insulation Coating Particles 3)

In the synthesis of the insulating coating particles 1 , a dispersion liquid of the insulating coating particles was produced in the same manner except that the amount of the tetraethoxy decane in the shell raw material dispersion was changed to three times. Observation by SEM revealed an average particle diameter of 363 nm and a coefficient of variation (C.V.) of the particle diameter of 4.4%. The moisture absorption rate was calculated and found to be 3.0% by mass. The eluted ammonium ion concentration was measured and found to be 19 ppm.

In addition, the fluorenone oligomer 1 having the same weight as the weight of the particles was added to the dispersion liquid of the insulating coating particles and stirred for 2 hours to obtain the insulating coating particles 3 treated with the fluorenone oligomer. Thereafter, the mixture was centrifuged three times, and after washing the particles, they were dispersed in methanol.

(Production of Insulation Coating Particles 4)

The following compound was added in one portion to a 500 ml flask, and the mixture was stirred while stirring in a water bath at a temperature of 80 ° C for 1 hour. After the dropwise addition, the mixture was stirred for 5 hours, and allowed to stand for 5 hours. After 20 hours, a dispersion of particles for insulating coating was obtained.

[Shell raw material dispersion 2]

Centrifuging the obtained particle dispersion and repeating it several times After redispersing in methanol, observation by SEM revealed an average particle diameter of 312 nm and a coefficient of variation (C.V.) of the particle diameter of 4.5%. Further, 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 and found to be 21 ppm.

In addition, the fluorenone oligomer 1 having the same weight as the weight of the particles was added to the dispersion liquid of the insulating coating particles and stirred for 2 hours to obtain the insulating coating particles 4 having a surface treated with an fluorenone oligomer. Thereafter, the mixture was centrifuged three times, and after washing the particles, they were dispersed in methanol.

(Production of Insulation Coating Particles 5)

The following compound was added to a 500 ml flask at a time, and the mixture was stirred while stirring in a water bath at a temperature of 80 ° C for 1 hour, and the mixture was stirred for 5 hours, and then allowed to stand for 5 hours while stirring. After 20 hours, a dispersion of particles for insulating coating was obtained.

[Shell Raw Material Dispersion 3"

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

In addition, the fluorenone oligomer 1 having the same weight as the weight of the particles was added to the dispersion liquid of the insulating coating particles and stirred for 2 hours to obtain the insulating coating particles 5 having a surface treated with an fluorenone oligomer. Thereafter, the mixture was centrifuged three times, and after washing the particles, they were dispersed in methanol.

(Production of Insulation Coating Particles 6)

In the synthesis of the insulating coating particles 4, a dispersion liquid of the insulating coating particles was produced in the same manner except that the shell raw material dispersion liquid 2 was added twice in two hours. Observation by SEM revealed an average particle diameter of 365 nm and a coefficient of variation (C.V.) of the particle diameter of 4.8%. The moisture absorption rate was calculated and found to be 1.0% by mass. The eluted ammonium ion concentration was measured and found to be 40 ppm.

In addition, the fluorenone oligomer 1 having the same weight as the weight of the particles was added to the dispersion liquid of the insulating coating particles and stirred for 2 hours to obtain the insulating coating particles 6 having a surface treated with an fluorenone oligomer. Thereafter, the mixture was centrifuged three times, and after washing the particles, they were dispersed in methanol.

(Production of Insulation Coating Particles 7)

In the synthesis of the insulating coating particles 4, the core particles 2 are used in place of the core particles 1, and the shell material dispersion liquid 2 is added in three times over three hours, and the dispersion of the insulating coating particles is produced in the same manner. liquid. Observation by SEM revealed an average particle diameter of 316 nm and a coefficient of variation (C.V.) of the particle diameter of 3.5%. The moisture absorption rate was calculated and found to be 1.2% by mass. The eluted ammonium ion concentration was measured and found to be 20 ppm.

In addition, the fluorenone oligomer 1 having the same weight as the weight of the particles was added to the dispersion liquid of the insulating coating particles and stirred for 2 hours to obtain the insulating coating particles 7 having a surface treated with an fluorenone oligomer. Thereafter, the mixture was centrifuged three times, and after washing the particles, they were dispersed in methanol.

(Production of Insulation Coating Particles 8)

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

In addition, the fluorenone oligomer 1 having the same weight as the weight of the particles was added to the dispersion liquid of the insulating coating particles and stirred for 2 hours to obtain the insulating coating particles 8 having a surface treated with an fluorenone oligomer. Thereafter, the mixture was centrifuged three times, and after washing the particles, they were dispersed in methanol.

(Production of Insulation Coating Particles 9)

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

In addition, the fluorenone oligomer 1 having the same weight as the weight of the particles was added to the dispersion liquid of the insulating coating particles and stirred for 2 hours to obtain the insulating coating particles 9 having a surface treated with an fluorenone oligomer. Thereafter, The mixture was centrifuged three times, and after washing the particles, they were dispersed in methanol.

(Production of Insulation Coating Particles 10)

The core particles 1 are made of the insulating coating particles 10. The moisture absorption rate was calculated and found to be 0.5% by mass. The eluted ammonium ion concentration was measured and found to be 30 ppm.

(Production of Insulation Coating Particles 11)

After the preparation of the core particles 3, a mixture of the following compounds was added dropwise to the dispersion of the core particles 3 obtained above for 1 hour, and further polymerization was carried out for 4 hours to obtain particles 11 for insulating coating.

The particles were observed by SEM, and 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 and found to be 1.0% by mass. The eluted ammonium ion concentration was measured and found to be 40 ppm.

(Production of Insulation Coating Particles 12)

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

(Measurement of the thickness of the shell layer)

With respect to the insulating coating particles 1 to the insulating coating particles 12, the thickness of the shell layer is calculated from the average particle diameter before and after the shell formation. 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 μm was formed on the surface of the crosslinked polystyrene particles having an average particle diameter of 3.0 μm by electroless plating, and a palladium layer having a thickness of 0.04 μm was formed on the outer side of the nickel to obtain a conductive layer. particle.

(insulation coating of conductive particles)

A reaction liquid was prepared by dissolving 8 mmol of thioglycolic acid in 200 mL of methanol. To the reaction liquid, 10 g of conductive particles were added, and the mixture was stirred at room temperature for 3 hours with a stirring blade having a diameter of 45 mm using a three-one motor (Three-One Motor), and then the surface of the conductive particles was treated with thioglycolic acid. The treated conductive particles were taken out by filtration using a membrane filter (manufactured by Millipore) having a pore diameter of 3 μm, and the taken-out conductive particles were washed with methanol to obtain a conductive layer having a carboxyl group on the surface. Particle 1g.

A 30% aqueous solution of polyethyleneimine (manufactured by Wako Pure Chemical Industries, Ltd.) having a molecular weight of 70,000 was diluted with ultrapure water to obtain a 0.3 mass% aqueous solution of polyethyleneimine. To the polyethyleneimine aqueous solution, 1 g of the conductive particles having a carboxyl group on the surface obtained above was added, and the mixture was stirred at room temperature for 15 minutes. Then, 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, followed by stirring at room temperature for 5 minutes. Thereafter, 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 conductive particles on the membrane filter were washed twice with 200 g of ultrapure water to remove unadsorbed particles. Polyethyleneimine. By the above operation, conductive particles having polyethyleneimine adsorbed on the surface were obtained.

Then, the conductive particles treated with the polyethyleneimine were immersed in isopropyl alcohol, and then the dispersion liquid of the insulating coating particles 1 to the insulating coating particles 12 was dropped, thereby preparing a fine particle coating ratio of 30%. The insulating coated conductive particles. The coverage rate is adjusted by the amount of dripping.

Then, 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, followed by stirring at room temperature for 5 minutes. Then, 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 conductive particles on the membrane filter were washed twice with 200 g of ultrapure water, and the insulating coating was removed. Conductive particles that are not adsorbed by particles. Then, the insulating coated conductive particles were dried by heating at 80 ° C, 30 minutes, and 120 ° C for 1 hour.

Then, 10 g of the insulating coated conductive particles were added to 100 g of a treatment liquid in which an anthrone oligo 2 (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KR-212) having the same weight as the weight of the particles was dissolved, and at room temperature. The one-hour condition was stirred using a Sany motor. Thereafter, the particles are taken out by filtration, and the taken insulating coated conductive particles are washed with methanol and then dried to obtain insulating coated conductive particles 1 to insulating coated conductive particles 12 having fluorenone oligomer 2 adhered on the surface thereof. .

(Solvent resistance test of particles for insulating coating)

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), subjected to ultrasonic irradiation (24 kHz) for 5 minutes, and then confirmed by insulating coating by SEM. The particles were confirmed to have peeled off the particles for insulation coating. The case where the adsorption amount of the particles for insulating coating does not change is A, and the case where the particles for insulating coating are partially peeled off is C. The results will be shown in Table 3.

(Production of an anisotropic conductive film and circuit connection using an anisotropic conductive film)

100 g of phenoxy resin (manufactured by Union Carbide Co., Ltd., trade name: PKHC), and acrylic rubber (40 parts by mass of butyl acrylate, 30 parts by mass of ethyl acrylate, 30 parts by mass of acrylonitrile, methyl group) 3 parts by mass of a copolymer of glycidyl acrylate, weight average molecular weight: 850,000) 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% by mass solution. A liquid epoxy resin containing a microcapsule-type latent hardener was added to the solution (epoxy equivalent weight 185, limited by Asahi Kasei Epoxy) The company manufactured, trade name: Novacure HX-3941) 300 g, and stirred to prepare an adhesive solution.

The above-mentioned insulating coated conductive particles having an fluorenone oligomer attached to the surface are dispersed in the adhesive solution. The concentration thereof was set to 9% by volume based on the amount of the adhesive solution. The obtained dispersion was applied onto a separator (an anthrone-treated polyethylene terephthalate film having a thickness of 40 μm) using a roll coater, and heated at 90 ° C for 10 minutes. It was dried to form an anisotropic conductive film having a thickness of 25 μm on the separator.

Then, using the produced anisotropic conductive film, gold bumps were formed according to the procedures of i) to iii) shown below (area: 30 μm × 90 μm, interval 12 μm, height: 15 μm, convex A wafer of 362) (1.7 mm × 1.7 mm, thickness: 0.5 μm) was connected to a glass substrate (thickness: 0.7 mm) with an ITO circuit to form a connection structure sample (Examples 1 to 9). And Comparative Example 1 to Comparative Example 3).

i) An anisotropic conductive adhesive film (2 mm × 19 mm) was attached to a glass substrate with an ITO circuit at a pressure of 0.98 MPa (10 kgf/cm ² ) at 80 °C.

Ii) Peel the separator to align the bumps of the wafer with the glass substrate with the ITO circuit.

Iii) The above connection was carried out by heating and pressurizing from above the wafer under conditions of 190 ° C and 40 MPa (low-pressure mounting conditions) for 10 seconds.

(Insulation resistance test and on-resistance test)

An insulation resistance test and an on-resistance test were performed on the produced connection structure samples. The anisotropic conductive film is important in that the insulation resistance between the wafer electrodes is high and the on-resistance between the wafer electrodes/glass electrodes is low. The insulation resistance between the wafer electrodes of 10 samples was measured. The insulation resistance is a value obtained by measuring the initial value and a reliability test (migration test) of leaving the temperature at 60 ° C, a humidity of 90%, and applying 20 V for 1000 hours. In addition, the yield when the insulation resistance after the reliability test was 10 ⁹ Ω or more was determined as a good product.

Regarding the on-resistance between the wafer electrode and the glass electrode, the average value of the 14 samples was measured. The on-resistance is a value obtained by measuring the initial value and a reliability test (moisture absorption heat resistance test) for 1000 hours under the conditions of a temperature of 85 ° C and a humidity of 85%. The measurement results are shown in Table 3.

A summary of the results of the insulation resistance test and the on-resistance test in Table 3 is shown in Table 4. As the on-resistance evaluation, the case where the on-resistance before the reliability test is 1 Ω or less is A, and the case where the on-resistance before the reliability test exceeds 1 Ω and is 5 Ω or less is set to B, and the reliability test is performed. The case where the previous on-resistance exceeds 5 Ω is set to C. In the evaluation of the insulation reliability, the case where the yield before the reliability test is 100% or less and 80% or more is A, and the case where the yield before the reliability test is less than 80% and 50% or more is set. For B, the case where the yield before the reliability test is less than 50% is C. Further, as the evaluation of the connection reliability, the on-resistance after the reliability test is 0 Ω or more, the case where the voltage is less than 50 Ω is A, and the on-resistance after the reliability test is 50 Ω or more and less than 100 Ω. The case is B, and the case where the on-resistance after the reliability test is 100 Ω or more is C.

As shown in Table 3, the sample of the connected structure of Examples 1 to 9 is Before and after the reliability test, it showed good on-resistance, insulation reliability and connection reliability. It is presumed that the reason is that heat resistance and solvent resistance can be imparted to the particles by forming the shell layer on the core particles using the anthrone-based compound. In addition, Examples 1 to 9 maintained a yield of 100% even after the reliability test.

When polymer particles having no core-shell structure or particles having the same polymer as the core and the shell are used as the particles for insulating coating, the results are as follows: although the initial on-resistance is good, insulation reliability and connection reliability are poor ( Comparative Example 1 and Comparative Example 2). It is presumed that the reason is that the polymer particles have poor solvent resistance, so that the particles for insulating coating are peeled off during resin kneading, and the insulation reliability is low. Further, it is estimated that the polymer particles have low heat resistance and a high coefficient of thermal expansion, which affects connection reliability. In addition, when cerium oxide particles were used as the particles for insulating coating, the on-resistance was high (Comparative Example 3). It is presumed that the reason is that since the elastic modulus of the particles is high, deformation of the particles becomes difficult, and conduction becomes difficult.

1‧‧‧Insulation coated particles

1a‧‧‧nuclear particles

1b‧‧‧ shell

2‧‧‧Substrate particles

2a‧‧‧Spherical core particles

2b‧‧‧metal layer

10‧‧‧Insulated coated conductive particles

20‧‧‧Insulating adhesive resin

20a‧‧‧Attenuation of insulating adhesive resin

30‧‧‧1st circuit component

31‧‧‧Circuit board (first circuit board)

31a‧‧‧Main surface of the first circuit board

32‧‧‧Circuit electrode (first circuit electrode)

40‧‧‧2nd circuit component

41‧‧‧Circuit board (second circuit board)

41a‧‧‧Main surface of the second circuit board

42‧‧‧Circuit electrode (2nd circuit electrode)

50‧‧‧ anisotropic conductive film

50a‧‧‧Connecting Department

100‧‧‧Connection structure

A, B‧‧ arrows

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 an 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(a) to 4(c) are cross-sectional views schematically showing an example of a method of manufacturing the connection structure.

1‧‧‧Insulation coated particles

1a‧‧‧nuclear particles

1b‧‧‧ shell

2‧‧‧Substrate particles

2a‧‧‧Spherical core particles

2b‧‧‧metal layer

10‧‧‧Insulated coated conductive particles

Claims (15)

An insulating coating particle comprising: a substrate particle containing a conductive metal on a surface thereof to form an insulating coated conductive particle, wherein the insulating coating particle has a core-shell structure having a core particle and a shell layer, and the core particle contains an organic layer In the polymer, the shell layer contains an anthrone-based compound, and the anthrone-based compound has at least one selected from the group consisting of SiO _4/2 units, RSiO _3/2 units, and R ₂ SiO _2/2 units. Unit (herein, R represents a group 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 γ-(meth)acryloxypropyl group. At least one of the groups). The insulating coating particles according to claim 1, wherein the shell layer contains a functional group having a bonding property to the substrate particles. The insulating coating particles according to the second aspect of the invention, wherein the functional group having a bonding property to the substrate particles is an epoxy group or a glycidyl group. The insulating coating particles according to any one of claims 1 to 3, wherein the shell layer is treated with an anthranone oligomer having an epoxy group or a glycidyl group. The insulating coating particles according to any one of the items 1 to 3, wherein the shell layer has a thickness of from 1 nm to 150 nm. The insulating coating particles according to any one of the preceding claims, wherein the shell layer comprises an anthrone-based compound having only SiO _4/2 units, and the shell layer has a thickness of 1 nm. 50nm. The particles for insulating coating according to any one of the items 1 to 3, wherein the particles have an average particle diameter of 1 μm or less and a coefficient of variation of the particle diameter of 10% or less. The particles for insulating coating according to any one of claims 1 to 3, which have a moisture absorption rate of 5% by mass or less. The particles for insulating coating according to any one of claims 1 to 3, wherein the eluted ammonium ion concentration is 100 ppm or less. The insulating coating particles according to any one of claims 1 to 3, wherein the shell layer is formed by a reaction in which a tertiary amine or a sulfonic acid compound is used as a catalyst. The particles for insulating coating according to any one of the above-mentioned claims, wherein the surface of the core particle has an amine group or a carboxyl group. The insulating coating particle according to any one of the above-mentioned claims, wherein the core particle has a diionic functional group. An insulating coated conductive particle, comprising: the insulating coating particle according to any one of claims 1 to 12, and a substrate particle coated with at least a part of the surface by the insulating coating particle. An anisotropic conductive material comprising: an insulating binder resin, and an insulating coated conductive particle according to claim 13 which is dispersed in the above-mentioned insulating binder resin. A connection structure comprising: a pair of circuit members disposed opposite each other; a connecting portion comprising the cured material of the anisotropic conductive material according to claim 14 and interposed between the pair of circuit members, and electrically connecting the circuit electrodes of the respective circuit members to each other The above circuit members are connected to each other.