JP2012140625A - Adhesive heat-conducting member and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive heat-conducting member excellent in both of thermal conductivity and adhesiveness, and to provide a method for producing the member.SOLUTION: The adhesive heat-conducting member comprises an inorganic-polymer composite material where a hydrophilic inorganic compound having a maximum length or a primary particle average diameter of 1 to 1,000 nm is unevenly distributed on the surfaces of the polymer particles having a median diameter of 0.05 to 100 μm on a volume basis. The adhesive heat-conducting member is obtained by the production method of an adhesive heat-conducting member, the method including steps of: dispersing a hydrophilic inorganic compound in water to prepare an aqueous dispersion of the inorganic compound; compounding the aqueous dispersion with an ethylenically unsaturated monomer and emulsifying the ethylenically unsaturated monomer to prepare a monomer emulsion; compounding a surfactant into at least one of water, the aqueous dispersion, the ethylenically unsaturated monomer and the monomer emulsion; and polymerizing the ethylenically unsaturated monomer in the monomer emulsion.

Description

  The present invention relates to an adhesive heat conductive member and a method for manufacturing the same, and more particularly to an adhesive heat conductive member preferably used for a microprocessor and an electronic device and a method for manufacturing the same.

  2. Description of the Related Art Conventionally, in electronic devices such as notebook personal computers, there is a demand for efficiently releasing heat generated from a CPU or the like as performance and size are reduced.

  For example, in a microprocessor including a heat spreader, a heat sink disposed opposite to the heat spreader, and a heat dissipation interface material (TIM2) interposed therebetween, silicone grease containing a heat conductive filler is used as the heat dissipation interface material. (For example, refer nonpatent literature 1). In the microprocessor described in Non-Patent Document 1, heat conducted to the heat spreader is released to the heat sink through the heat dissipation interface material.

Kunihiko Mita, Silicone Review 64 “Advances in Silicone Grease for Heat Dissipation”, [online], April 2004 issue, Internet <URL: http: // www. silicone. jp / j / sil / _news / 97 / images / view_97. pdf>

  However, since the heat dissipation interface material of the microprocessor proposed in Non-Patent Document 1 has insufficient adhesive force, it is easily peeled off from the heat spreader or the heat sink.

  An object of the present invention is to provide an adhesive heat conductive member excellent in both heat conductivity and adhesiveness, and a method for producing the same.

  In order to achieve the above object, the adhesive heat conductive member of the present invention has a maximum length or a primary average particle diameter of 1-1000 nm on the surface of a polymer particle having a volume-based median diameter of 0.05-100 μm. It is characterized by comprising an inorganic-polymer composite material in which the hydrophilic inorganic compound is unevenly distributed.

  In the adhesive heat conductive member of the present invention, it is preferable that the polymer particles are obtained by polymerizing an ethylenically unsaturated monomer.

  Moreover, in the adhesive heat conductive member of this invention, it is suitable for the said ethylenically unsaturated monomer to contain the (meth) acrylic-acid alkylester.

  In the adhesive heat conductive member of the present invention, it is preferable that the ethylenically unsaturated monomer further contains a copolymerizable vinyl monomer copolymerizable with the (meth) acrylic acid alkyl ester.

  In the adhesive heat conductive member of the present invention, it is preferable that the blending ratio of the copolymerizable vinyl monomer is 40 parts by weight or less with respect to 100 parts by weight of the ethylenically unsaturated monomer.

  Moreover, in the adhesive heat conductive member of this invention, it is suitable to form in the film form of thickness 1.0-100 micrometers.

  Moreover, in the adhesive heat conductive member of this invention, it is suitable that the content rate of the said inorganic compound is 4-200 weight part with respect to 100 weight part of said polymer particles.

  In the adhesive heat conductive member of the present invention, it is preferable that the polymer particles are water-dispersed polymer particles.

  In the adhesive heat conductive member of the present invention, it is preferable that the inorganic compound is a hydrophilic inorganic compound having a bulk shape, a needle shape, or a plate shape.

  In the adhesive heat conductive member of the present invention, it is preferable that the inorganic compound is supported in a dispersed state on the surface of the polymer particles.

  The method for producing an adhesive heat conductive member of the present invention includes a step of dispersing a hydrophilic inorganic compound in water to prepare an aqueous dispersion of the inorganic compound, the aqueous dispersion, the ethylenically unsaturated monomer, And a step of emulsifying the ethylenically unsaturated monomer to prepare a monomer emulsion, and adding a surfactant to at least one of water, the aqueous dispersion, the ethylenically unsaturated monomer, and the monomer emulsion And a step of polymerizing the ethylenically unsaturated monomer in the monomer emulsion.

  In the inorganic-polymer composite material that forms the adhesive heat conductive member of the present invention obtained by the method for producing the adhesive heat conductive member of the present invention, hydrophilic inorganic compounds are unevenly distributed on the surface of the polymer particles. Therefore, while maintaining the mechanical properties of the polymer particles in the adhesive heat conducting member, the adhesive heat conducting member is further excellent in both thermal conductivity and adhesiveness.

  Therefore, in the microprocessor and the electronic apparatus including the adhesive heat conducting member, the heat conducted to the heat spreader can be efficiently radiated by releasing the heat to the cooling unit efficiently by the adhesive heat conducting member. .

  In addition, excellent heat dissipation can be ensured by long-term use of the microprocessor and the electronic device.

1 shows a cross-sectional view of a microprocessor including an embodiment of an adhesive heat conducting member of the present invention. The front view for demonstrating arrangement | positioning of the heat conductive member in evaluation of the heat dissipation of an Example is shown. The image processing figure of the SEM photograph of the inorganic-polymer composite material in the heat conductive member of Example 2 is shown. The image processing figure of the SEM photograph of the inorganic-polymer composite material in the heat conductive member of Example 3 is shown. The image processing figure of the SEM photograph of the inorganic-polymer composite material in the heat conductive member of Example 4 is shown. The image processing figure of the SEM photograph of the inorganic-polymer composite material in the heat conductive member of Example 5 is shown. The image processing figure of the SEM photograph of the inorganic-polymer composite material in the heat conductive member of Example 6 is shown. The image processing figure of the TEM photograph of the inorganic-polymer composite material in the heat conductive member of Example 7 is shown. The image processing figure of the TEM photograph of the inorganic-polymer composite material in the heat conductive member of the comparative example 2 is shown.

  The adhesive heat conducting member (heat conducting member) of the present invention is composed of an inorganic-polymer composite material, and in this inorganic-polymer composite material, hydrophilic inorganic compounds are unevenly distributed on the surface of polymer particles. That is, a hydrophilic inorganic compound is supported in a dispersed state on the surface of the polymer particles. Such an inorganic-polymer composite material can be obtained as a polymer latex by the production method described below.

  That is, this inorganic-polymer composite material comprises a step of dispersing a hydrophilic inorganic compound in water to prepare an aqueous dispersion of the inorganic compound (aqueous dispersion preparation step), an aqueous dispersion and an ethylenically unsaturated monomer. And a step of preparing a monomer emulsion by emulsifying an ethylenically unsaturated monomer (monomer emulsion preparation step) and at least one of water, an aqueous dispersion, an ethylenically unsaturated monomer, and a monomer emulsion. It can be obtained as a polymer latex by a production method comprising a step of blending an agent (surfactant blending step) and a step of polymerizing an ethylenically unsaturated monomer in the monomer emulsion (polymerization step).

  In the present invention, the inorganic compound is an inorganic compound that is hydrophilic and has a bulk shape, a needle shape, or a plate shape (excluding a layer shape).

  Examples of the bulk-shaped inorganic compound include a spherical shape, a rectangular parallelepiped shape, or an irregularly shaped inorganic compound thereof. Examples of the bulk inorganic compound include silica, calcium carbonate, titanium oxide, tin oxide (including antimony-doped tin oxide), alumina, magnesium hydroxide, barium titanate, zinc oxide, silicon nitride, and other metal fine particles. Is mentioned.

  Examples of the needle-shaped inorganic compound include potassium titanate, wollastonite, sepiolite, acicular tin oxide, acicular magnesium hydroxide, and the like.

  The plate-shaped inorganic compound is a plate-shaped inorganic compound excluding a layer-shaped inorganic compound such as a layered clay mineral, and examples thereof include boron nitride, plate-like calcium carbonate, and plate-like aluminum hydroxide.

  These inorganic compounds can be used alone or in combination of two or more. Preferably, antimony-doped tin oxide, alumina, titanium oxide, zinc oxide, boron nitride, and silicon nitride are used.

  As such inorganic compounds, general commercial products can be used. For example, more specifically, as antimony-doped tin oxide, for example, SN-100S, SN-100P, SN-100D manufactured by Ishihara Sangyo Co., Ltd. Examples of (water-dispersed product) and titanium oxide include TTO series manufactured by Ishihara Sangyo Co., Ltd., and examples of zinc oxide include SnO-310, SnO-350 and SnO-410 manufactured by Sumitomo Osaka Cement.

  In the case of a bulk-shaped (spherical) inorganic compound, the size of the inorganic compound is, for example, 1 to 1000 nm, preferably 1 to 200 nm, and more preferably 5 to 100 nm as the primary average particle diameter. If it is larger than the above range, oil droplets with the desired particle size may not be obtained.

  In the case of a needle-shaped inorganic compound or a plate-shaped inorganic compound, the maximum length is, for example, 1 to 1000 nm, preferably 1 to 200 nm, and more preferably 5 to 200 nm. If it is larger than the above range, oil droplets with the desired particle size may not be obtained. Furthermore, these aspect ratios are expressed by the major axis length / minor axis length or major axis length / thickness in the case of a needle shape, and the diagonal length in the case of a plate shape. / Thickness or long side length / thickness) is, for example, 5 to 200, preferably 10 to 100.

  In addition, the inorganic compound is present at the interface between water and oil droplets of the ethylenically unsaturated monomer in the monomer emulsion preparation process, and is supported so as to be unevenly distributed on the surface of the water-dispersed resin after the polymerization process. It is necessary to

  Therefore, if the above-mentioned inorganic compound is hydrophobic, it will exist stably in the oil phase in the monomer emulsion preparation process, and cannot exist at the interface between water and oil droplets. Disappear. On the other hand, when the hydrophilicity of the inorganic compound is excessively high, it exists stably in water, and again cannot exist at the interface between water and oil droplets of the ethylenically unsaturated monomer. In some cases, it cannot be emulsified.

  Therefore, when the above-mentioned inorganic compound is excessively hydrophilic and cannot be emulsified, the surface of the inorganic compound is partially surface-treated with a surface treatment agent as necessary.

  Examples of the surface treatment agent include general surface modifiers such as coupling agents and fatty acids.

  Examples of the coupling agent include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent.

  Examples of the silane silane coupling agent include 3-methacryloxypropyl-trimethoxysilane, 3-acryloxypropyl-trimethoxysilane, 3-methacryloxypropyl-triethoxysilane, and 3-acryloxypropyl-triethoxysilane. 3-methacryloxypropylmethyl-dimethoxysilane, 3-acryloxypropylmethyl-dimethoxysilane, 3-methacryloxypropylmethyl-diethoxysilane, 3-acryloxypropylmethyl-diethoxysilane, vinyltrimethoxysilane, vinyltri Ethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-metac Ruoxydecyltrimethoxysilane, 10-acryloxydecyltrimethoxysilane, 10-methacryloxydecyltriethoxysilane, 10-acryloxydecyltriethoxysilane, methyltrimethoxysilane, butyltrimethoxysilane, hexyltrimethoxysilane, decyl Trimethoxysilane, hexadecyltrimethoxysilane, octadecyldimethylmethoxysilane, tetramethoxysilane, tetraethoxysilane, dimethoxydimethylsilane, methoxytrimethylsilane, diethoxydimethylsilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane , Phenyltriethoxysilane, dimethoxydiphenylsilane, diphenylethoxymethylsilane, dimethoxymethylphenylsilane Emissions, such as hexamethyldisilazane and the like.

  Examples of the titanium-based coupling agent include isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctylpyrophosphate) titanate, tetraisopropylbis (dioctylphosphite) titanate, tetraoctylbis (ditridecylphosphite). ) Titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltri (dioctylphosphate) Titanate, isopropyl tricumylphenyl titanate, isopropyl tri (N-amidoethyl acetate) Aminoethyl) such as titanate, and the like.

  Examples of the aluminum coupling agent include acetoalkoxyaluminum diisopropylate.

  Examples of the fatty acid include stearic acid, oleic acid, linoleic acid, linolenic acid, and eleostearic acid.

  As the surface treatment with such a surface treatment agent, for example, the above-described inorganic compound is stirred in a mixer, and a dry method in which an alcohol aqueous solution, an organic solvent solution or an aqueous solution of the surface treatment agent is added, for example, the above-described inorganic Examples include a wet method in which a compound is dispersed in an alcohol aqueous solution or an aqueous solution, and then a surface treatment agent is added, for example, a spray method in which the surface treatment agent is sprayed onto the above-described inorganic compound.

  In addition, the above-mentioned inorganic compound with excessively high hydrophilicity can use the commercial item surface-treated beforehand.

  Examples of the ethylenically unsaturated monomer include (meth) acrylic acid alkyl ester.

  The (meth) acrylic acid alkyl ester is, for example, a (meth) acrylic acid alkyl ester (methacrylic acid alkyl ester and / or acrylic acid alkyl ester) having an alkyl group having 1 to 18 carbon atoms. ) Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, ( T-butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate , (Meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid Sooctyl, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate (Meth) acrylic acid tetradecyl, (meth) acrylic acid pentadecyl, (meth) acrylic acid hexadecyl, (meth) acrylic acid heptadecyl, (meth) acrylic acid octadecyl, (meth) acrylic acid 2-ethylhexadecyl ) Alkyl acrylate (linear or branched alkyl having 1 to 18 carbon atoms) ester. Among these (meth) acrylic acid alkyl esters, butyl acrylate, methyl methacrylate, and 2-ethylhexadecyl (meth) acrylate are preferable. These alkyl (meth) acrylates can be used alone or in combination of two or more.

  Moreover, as an ethylenically unsaturated monomer, the copolymerizable vinyl monomer copolymerizable with (meth) acrylic-acid alkylester can be mentioned.

  Examples of the copolymerizable vinyl monomer include aromatic vinyl monomers such as styrene and vinyl toluene, such as cyclopentyl di (meth) acrylate, cyclohexyl (meth) acrylate, bornyl (meth) acrylate, and (meth) acrylic acid. (Meth) acrylic acid alicyclic hydrocarbon esters such as isobornyl, for example, (meth) acrylic aryl esters such as phenyl (meth) acrylate, such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate Alkoxy group-containing unsaturated monomers such as ethylene, propylene, isoprene, butadiene, isobutylene and other olefinic monomers, vinyl ether-based monomers such as vinyl ether, halogen atom-containing unsaturated monomers such as vinyl chloride, etc. For example, N-vinylpyrrolidone, N- (1-methylvinyl) pyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N -Acrylic ester monomers containing halogen atoms such as fluorine atoms, such as vinyl group-containing heterocyclic compounds such as vinyl oxazole, N-vinyl morpholine, tetrahydrofurfuryl (meth) acrylate, for example, fluorine (meth) acrylate Etc.

  Examples of the copolymerizable vinyl monomer include functional group-containing vinyl monomers, for example, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, crotonic acid, and carboxyethyl (meth) acrylate. Carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate, for example, hydroxyl group-containing vinyl monomers such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-methylol (meta Acrylamide Amide group-containing unsaturated monomers such as N-methylolpropane (meth) acrylamide and N-vinylcarboxylic acid amide, such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, (meth) Amino group-containing unsaturated monomers such as acrylic t-butylaminoethyl, for example, glycidyl group-containing unsaturated monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate, for example, cyano such as acrylonitrile and methacrylonitrile Group-containing unsaturated monomers, for example, isocyanate group-containing unsaturated monomers such as 2-methacryloyloxyethyl isocyanate, such as styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) Acrylamide Pro Sulfonic acid group-containing unsaturated monomers such as sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide, etc. Maleimide monomers such as N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethyl hexylitaconimide, N-cyclohexyl leuconconimide, N-lauryl itaconimide Itaconic imide monomers such as N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-o Succinimide monomers such as cyoctamethylene succinimide, for example, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, (meth) acrylic And glycol-based acrylic ester monomers such as methoxypolyethylene glycol acid and methoxypolypropylene glycol (meth) acrylate.

  Furthermore, a polyfunctional monomer is mentioned as an above-described functional group containing vinyl monomer.

  Examples of the multifunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and tetraethylene glycol di (meth) acrylate. (Mono or poly) alkylene glycol di (meth) such as (mono or poly) ethylene glycol di (meth) acrylate and (mono or poly) propylene glycol di (meth) acrylate such as propylene glycol di (meth) acrylate In addition to acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol Examples include (meth) acrylic acid ester monomers of polyhydric alcohols such as tall tri (meth) acrylate and dipentaerythritol hexa (meth) acrylate, such as divinylbenzene. Examples of the polyfunctional monomer include epoxy acrylate, polyester acrylate, and urethane acrylate.

  Furthermore, examples of the copolymerizable vinyl monomer include alkoxysilyl group-containing vinyl monomers. Examples of the alkoxysilyl group-containing vinyl monomer include silicone-based (meth) acrylate monomers and silicone-based vinyl monomers.

  Examples of the silicone-based (meth) acrylate monomer include (meth) acryloyloxymethyl-trimethoxysilane, (meth) acryloyloxymethyl-triethoxysilane, 2- (meth) acryloyloxyethyl-trimethoxysilane, 2- ( (Meth) acryloyloxyethyl-triethoxysilane, 3- (meth) acryloyloxypropyl-trimethoxysilane, 3- (meth) acryloyloxypropyl-triethoxysilane, 3- (meth) acryloyloxypropyl-tripropoxysilane, 3 -(Meth) acryloyloxypropyl-triisopropoxysilane, (meth) acryloyloxyalkyl-trialkoxysilane such as 3- (meth) acryloyloxypropyl-tributoxysilane, for example, (meth) acryloyloxymethyl-methyl Dimethoxysilane, (meth) acryloyloxymethyl-methyldiethoxysilane, 2- (meth) acryloyloxyethyl-methyldimethoxysilane, 2- (meth) acryloyloxyethyl-methyldiethoxysilane, 3- (meth) acryloyloxypropyl -Methyldimethoxysilane, 3- (meth) acryloyloxypropyl-methyldiethoxysilane, 3- (meth) acryloyloxypropyl-methyldipropoxysilane, 3- (meth) acryloyloxypropyl-methyldiisopropoxysilane, 3- (Meth) acryloyloxypropyl-methyldibutoxysilane, 3- (meth) acryloyloxypropyl-ethyldimethoxysilane, 3- (meth) acryloyloxypropyl-ethyldiethoxysilane, 3- (meth) acryloyloxypropyl Ethyl dipropoxysilane, 3- (meth) acryloyloxypropyl-ethyldiisopropoxysilane, 3- (meth) acryloyloxypropyl-ethyldibutoxysilane, 3- (meth) acryloyloxypropyl-propyldimethoxysilane, 3- ( Examples include (meth) acryloyloxyalkyl-alkyl dialkoxysilanes such as (meth) acryloyloxypropyl-propyldiethoxysilane, and (meth) acryloyloxyalkyl-dialkyl (mono) alkoxysilanes corresponding to these.

  Examples of the silicone-based vinyl monomer include vinyltrialkoxysilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, and vinyl corresponding to these. Alkyldialkoxysilanes and vinyldialkylalkoxysilanes such as vinylmethyltrimethoxysilane, vinylmethyltriethoxysilane, β-vinylethyltrimethoxysilane, β-vinylethyltriethoxysilane, γ-vinylpropyltrimethoxysilane, γ -Vinylalkyl such as vinylpropyltriethoxysilane, γ-vinylpropyltripropoxysilane, γ-vinylpropyltriisopropoxysilane, γ-vinylpropyltributoxysilane Another trialkoxysilane, these correspond and (vinyl) alkyl dialkoxy silanes, and the like (vinyl alkyl) dialkyl (mono) alkoxysilanes.

  These copolymerizable vinyl monomers can be used alone or in combination of two or more.

  Of these copolymerizable vinyl monomers, an alkoxysilyl group-containing vinyl monomer is preferable.

  By using an alkoxysilyl group-containing vinyl monomer as the copolymerizable vinyl monomer, an alkoxysilyl group is introduced into the polymer chain, and a cross-linked structure can be formed by a reaction between them.

  Such a copolymerizable vinyl monomer is optionally used in combination with (meth) acrylic acid alkyl ester as necessary.

  The blending ratio of the copolymerizable vinyl monomer is, for example, 40 parts by weight or less, preferably 30 parts by weight or less, and more preferably 20 parts by weight or less with respect to 100 parts by weight of the ethylenically unsaturated monomer. When the copolymerizable vinyl monomer is an alkoxysilyl group-containing vinyl monomer, the blending ratio is, for example, 0.001 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic acid alkyl ester, preferably 0.01 to 5 parts by weight.

  Examples of the surfactant include known surfactants (surfactants listed in “Surfactant Physical Properties / Performance Manual, Noboru Moriyama, published by the Technical Information Society”), such as liquid and Dispersants that mainly act on the interface between the solids, for example emulsifiers that act mainly on the interface between the liquid and the liquid.

  Examples of the dispersant include a phosphoric acid dispersant and a carboxylic acid dispersant. Examples of the phosphate dispersant include sodium orthophosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium tetraphosphate, sodium hexametaphosphate, and trisodium phosphate. Examples of the carboxylic acid-based dispersant include polymer dispersants such as polyacrylic acid-based, polymethacrylic acid-based, acrylic acid / maleic acid copolymer system, and styrene / maleic acid copolymer system.

  As the polymer dispersant, a general commercial product can be used. For example, Aquaric series (polyacrylic acid type or acrylic acid / maleic acid copolymer system, manufactured by Nippon Shokubai Co., Ltd.), Aron series (polyacrylic acid type). Series, manufactured by Toagosei Co., Ltd., Charol series (polyacrylic acid, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Poise series (acrylic acid / maleic acid copolymer system, manufactured by Kao Corporation), SN Dispersant Series (polycarboxylic acid) Copolymer system, manufactured by San Nopco).

  Examples of the emulsifier include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, polyoxyethylene sodium lauryl sulfate, polyoxyethylene alkyl ether sodium sulfate, polyoxyethylene alkyl phenyl ether ammonium sulfate, and polyoxyethylene alkyl phenyl ether. Anionic emulsifiers such as sodium sulfate and sodium polyoxyethylene alkyl sulfosuccinate, for example, nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene polyoxypropylene block polymer Etc.

  Examples of the emulsifier include radical polymerizable (reactive) emulsifiers in which radical polymerizable functional groups (reactive groups) such as propenyl groups and allyl ether groups are introduced into these anionic emulsifiers and nonionic emulsifiers. .

  These surfactants can be used alone or in combination of two or more.

  And in order to obtain the inorganic-polymer composite material which forms the adhesive heat conductive member of this invention, for example, first, the above-mentioned inorganic compound and water are mix | blended, Then, these are stirred and mixed, hydrophilicity is carried out. An inorganic compound is dispersed in water to prepare an aqueous dispersion of the inorganic compound (aqueous dispersion preparation step).

  The compounding ratio of the inorganic compound is, for example, 0.1 to 50 parts by weight, preferably 0.2 to 40 parts by weight, and more preferably 0.5 to 30 parts by weight with respect to 100 parts by weight of water.

  If the blending ratio of the inorganic compound exceeds the above range, the viscosity of the aqueous dispersion may become excessively high or aggregation may occur in the polymerization step.

  On the other hand, if the blending ratio of the inorganic compound is less than the above range, the content ratio of the inorganic compound in the inorganic-polymer composite material becomes excessively low, and the inorganic compound cannot be uniformly supported on the surface of the water-dispersed resin. There is a case.

  In order to stir and mix the water mixed with the inorganic compound, for example, a known stirrer such as a disper or an ultrasonic homogenizer is used.

  In this stirring and mixing, the surface treatment of the surface of the inorganic compound described above can also be performed.

  Next, for example, an aqueous dispersion and an ethylenically unsaturated monomer are blended, followed by stirring and mixing to emulsify the ethylenically unsaturated monomer to prepare a monomer emulsion (monomer emulsion preparation step).

  In the blending of the aqueous dispersion and the ethylenically unsaturated monomer, the blending ratio of the inorganic compound is 4 to 200 parts by weight, preferably 5 to 150 parts by weight, more preferably 100 parts by weight of the ethylenically unsaturated monomer. Is 8 to 100 parts by weight.

  When the blending ratio of the inorganic compound is less than the above range, a stable emulsion form cannot be obtained in the monomer emulsion preparation step, and the coverage of the inorganic compound in the polymer particles becomes excessively low.

  On the other hand, if the blending ratio of the inorganic compound exceeds the above range, the coverage of the inorganic compound in the polymer particles becomes excessively high, the viscosity increases, and it may be necessary to adjust the viscosity.

  In order to emulsify the ethylenically unsaturated monomer, for example, an aqueous dispersion and an oil phase liquid containing the ethylenically unsaturated monomer are blended, and then, for example, these are emulsified by an emulsifying apparatus.

  The oil phase liquid contains, for example, an ethylenically unsaturated monomer as an essential component, and optionally contains an initiator and a hydrophobic compound as optional components.

  As the initiator, for example, a polymerization initiator usually used for emulsion polymerization is used, and for example, an oil-soluble initiator or a water-soluble initiator is used.

  Examples of the oil-soluble initiator include oil-soluble peroxide-based initiators such as benzoyl peroxide and lauroyl peroxide, such as dimethyl 2,2′-azobis (2-methylpropionate) (commercially available products such as V-601, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyldimethylvaleronitrile), 2,2′-azobis (2-methyl-butyronitrile), 1,1′-azobis (cyclohexane-1-carbononitrile), 2,2′-azobisisobutyronitrile (AIBN), azobis (2-methyl) And oil-soluble azo initiators such as butyronitrile).

  Examples of the water-soluble initiator include 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (2-methylpropionamidine) dihydrochloride, 2,2′-azobis ( 2-Amidinopropane) dihydrochloride, 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2′-azobis (N, N′-dimethyleneisobutyl) Azo initiators (excluding oil-soluble azo initiators) such as amidine), 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, such as potassium persulfate, Persulfate-based initiators such as ammonium persulfate, for example, t-butyl hydroperoxide, peroxide-based initiators such as hydrogen peroxide (excluding oil-soluble peroxide-based initiators), such as phenyl Substituted ethane initiators such as substituted ethanes, for example, carbonyl initiators such as aromatic carbonyl compounds, for example, redox systems such as combinations of persulfate and sodium bisulfite, peroxides and sodium ascorbate An initiator etc. are mentioned.

  These initiators are suitably used alone or in combination. Of the initiators, an oil-soluble initiator is preferably used, and an oil-soluble azo initiator is more preferably used.

  The mixing ratio of the initiator is appropriately selected, and is, for example, 0.005 to 1 part by weight with respect to 100 parts by weight of the ethylenically unsaturated monomer.

  Examples of the hydrophobic compound include higher alkanes having 8 to 30 carbon atoms such as dodecane, hexadecane, and octadecane, for example, higher alcohols having an alkyl group having 8 to 30 carbon atoms such as lauryl alcohol, cetyl alcohol, and stearyl alcohol. For example, alkyl (meth) acrylates having an alkyl group having 8 to 30 carbon atoms such as lauryl (meth) acrylate and stearyl (meth) acrylate, such as lauryl mercaptan, cetyl mercaptan, stearyl mercaptan and the like 8 to 30 carbon atoms. And thiols having an alkyl group of, for example, polymers such as polystyrene and polymethyl (meth) acrylate. These hydrophobic compounds can be used alone or in combination of two or more. Preferably, higher alkanes are used. In addition, when using an alkyl (meth) acrylate having an alkyl group having 8 to 30 carbon atoms as the ethylenically unsaturated monomer, the alkyl (meth) acrylate may function as a hydrophobic compound. , There is a case where it is not necessary to blend.

  The blending ratio of the hydrophobic compound is, for example, 1 to 80 parts by weight, preferably 1 to 60 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated monomer.

  If a hydrophobic compound is added to the oil phase liquid, the oil droplets in the monomer emulsion can be maintained at a median diameter in a specific range.

  In order to include an optional component in the oil phase liquid, an initiator and a hydrophobic compound are added to the ethylenically unsaturated monomer and dissolved.

  In the above description, the optional component is blended in the oil phase liquid, but it can also be added directly to the monomer emulsion, for example.

  Examples of the emulsifier include an ultrasonic homogenizer, a high-pressure homogenizer (PANDA 2K, manufactured by NIRO-SOAVI), a microfluidizer (manufactured by Microfluidics), a nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.), and a TK homomixer (manufactured by Primics). TK film mix (manufactured by Primics) is used.

  In the ultrasonic homogenizer, the frequency of the ultrasonic wave used is not particularly limited, and is, for example, 20 to 40 kHz. In the ultrasonic homogenizer, the oil droplets of the ethylenically unsaturated monomer are refined to the above-mentioned median diameter by the cavitation effect by ultrasonic irradiation.

  In the high-pressure homogenizer, microfluidizer, and nanomizer, the pressure applied is not particularly limited, and is, for example, 10 to 300 MPa. In high-pressure homogenizers, microfluidizers and nanomizers, while the dispersion is pressurized, it is ejected from the micropores, and the oil droplets are refined to the above-mentioned median diameter by the addition of the high shearing force generated in such ejection. The

  The TK homomixer and the TK fill mix are emulsifiers that utilize the high-speed rotation of the rotating body. When the rotating body rotates at a high speed in the mixed solution, a high shear force is added to the mixed solution, and oil droplets are generated. It is miniaturized to the median diameter described above.

  These emulsifiers can be used alone or in combination of two or more.

  Thereby, the volume-based median diameter of the oil droplets of the ethylenically unsaturated monomer to be emulsified is, for example, 100 μm or less, preferably 40 μm or less, more preferably 4 μm or less, and usually 0.05 μm or more.

  If the median diameter of the oil droplets exceeds the above range, aggregates may be generated in the polymerization step.

  The volume-based median diameter of oil droplets in this monomer emulsion is measured with a laser diffraction particle size distribution measuring device. As the laser diffraction type particle size distribution measuring device, a general commercial product is usually used, and specifically, LS13 320 (manufactured by Beckman Coulter, Inc.) or the like is used, and the measurement condition is that the laser light source is a laser diode and a tungsten lamp. And the wavelength is 450 to 900 nm.

  The monomer emulsion is then polymerized, for example, by heating, to polymerize the ethylenically unsaturated monomer in the monomer emulsion.

  The heating temperature (polymerization temperature) is set to, for example, 40 to 90 ° C., and the polymerization time is set to, for example, 1 to 10 hours.

  In addition, the monomer emulsion can be polymerized at a time under the reaction conditions described above, and after the polymerization of a part of the monomer emulsion, the remaining monomer emulsion can be polymerized, for example, dropwise, and further, the reaction It is also possible to charge water in advance in a container and raise the temperature to the above-described temperature, and then add the monomer emulsion dropwise or dividedly.

  Moreover, in this invention, surfactant is mix | blended with surfactant in at least any one of water, an aqueous dispersion, an ethylenically unsaturated monomer, and a monomer emulsion. The compounding ratio of the surfactant is, for example, 0.01 to 20 parts by weight, preferably 0.05 to 15 parts by weight with respect to 100 parts by weight of the inorganic compound.

  When the surfactant is blended with water, in the aqueous dispersion preparation step, the surfactant is added to the water before the inorganic compound is blended or the water before the inorganic compound is blended and dispersed. Added. Preferably, a dispersant is blended. By blending the surfactant with water, the primary particles of the inorganic compound that aggregates can be dispersed.

  In addition, when the surfactant is blended in the aqueous dispersion, the surfactant is added to the prepared aqueous dispersion in the monomer emulsion preparation step (after the aqueous dispersion preparation step). Preferably, a dispersant is added. By adding a surfactant to the aqueous dispersion, the dispersibility of the inorganic compound in the aqueous dispersion is improved, the viscosity of the aqueous dispersion is reduced, and the solid content concentration of the resulting emulsion is easily adjusted within a certain range. can do.

  Moreover, when mix | blending surfactant with an oil phase liquid, in a monomer emulsion preparation process, surfactant is added to the prepared oil phase liquid (specifically ethylenically unsaturated monomer). Preferably, an emulsifier is blended. By blending the surfactant into the oil phase liquid, a stable emulsion form of the monomer emulsion can be obtained.

  Moreover, when mix | blending surfactant with a monomer emulsion, surfactant is added to the prepared monomer emulsion in a superposition | polymerization process. Preferably, an emulsifier is blended. By blending the surfactant into the monomer emulsion, high polymerization stability can be obtained.

  By such polymerization, an inorganic compound can be obtained as an emulsion of an inorganic-polymer composite material supported on the surface of polymer particles (that is, water-dispersed polymer particles).

  In addition, solid content concentration of this emulsion is 5 to 50 weight%, for example, Preferably, it is 6 to 45 weight%, More preferably, it is 8 to 40 weight%. When the solid content concentration of the emulsion exceeds the above range, the viscosity of the emulsion in the polymerization step becomes excessively high, handling properties may be lowered, and control of the polymerization temperature may be difficult. If the solid content concentration of the emulsion is less than the above range, productivity may be reduced.

  The volume-based median diameter of the inorganic-polymer composite material in this emulsion is, for example, 100 μm or less, preferably 40 μm or less, more preferably 4 μm or less, and usually 0.05 μm or more. It is almost the same as the volume-based median diameter.

  Furthermore, the inorganic-polymer composite material includes, for example, a pH adjuster (such as an acetic acid aqueous solution), a crosslinking agent (isocyanate-based, epoxy-based, oxazoline-based, aziridine-based, metal chelate-based), chain transfer agent (as required) Thiols, etc.), viscosity modifiers, release modifiers, plasticizers, softeners, fillers (excluding the above-mentioned hydrophilic inorganic compounds), colorants (pigments, dyes, etc.), anti-aging agents, surfactants Etc. can be added at an appropriate ratio. These additives may be added after the polymerization step, or may be added to each liquid in the aqueous dispersion preparation step, the monomer emulsion preparation step, and the polymerization step.

  In the present invention, an aqueous dispersion is prepared so that a hydrophobizing agent such as a swelling agent (specifically, dodecyltrimethylammonium bromide or the like) is not added to the aqueous dispersion. When the hydrophobizing agent is added, the hydrophilicity of the inorganic compound is lowered and the dispersibility in the aqueous dispersion is lowered, so that the inorganic compound is not uniformly supported on the surface of the polymer particles.

  And, as described above, the inorganic-polymer composite material thus obtained is a hydrophilic inorganic material having a maximum length of 1-1000 nm on the surface of polymer particles having a volume-based median diameter of 0.05-100 μm. Compounds are composited so that they are ubiquitous. That is, in the inorganic-polymer composite material, the polymer particles carry the inorganic compound on the outer surface without encapsulating the inorganic compound.

  Therefore, in the heat conducting member made of an inorganic-polymer composite material of the present invention, a path in which inorganic compounds are continuous can be formed using polymer particles as a matrix. It can be suitably used as a heat conductive material (a material of a heat conduction member) that conducts heat to the path.

  FIG. 1 shows a cross-sectional view of a microprocessor comprising an embodiment of an adhesive heat conducting member of the present invention.

  Next, a microprocessor including an embodiment of the adhesive heat conducting member of the present invention will be described with reference to FIG.

  In FIG. 1, the microprocessor 1 is an LSI (Large Scale Integrated circuit) that houses a CPU 3 on a substrate 2. Specifically, the microprocessor 1 includes a substrate 2, a CPU 3 formed on the substrate 2, a first heat conducting member 4 formed on the CPU 3, and a first heat conducting member 4 on the substrate 2. Formed on the heat spreader 5, the second heat conductive member 6 as the heat conductive member (adhesive heat conductive member) formed on the heat spreader 5, and the second heat conductive member 6 A heat sink 7 is provided as a cooling unit.

  The substrate 2 has a flat plate shape, and is formed, for example, as a ceramic substrate made of glass or the like, for example, a metal substrate made of copper, aluminum, stainless steel, an iron alloy, or the like, for example, a plastic substrate made of polyimide or the like. In addition, a wiring circuit pattern (not shown) having connection terminals (not shown) is provided on the surface (upper surface) of the substrate 2, and the substrate 2 is formed as a wiring circuit board.

  The CPU 3 is a heating element that operates in response to an electrical signal and generates heat. For example, the CPU 3 is formed in a flat plate shape, and is disposed on the upper side of the substrate 2 with an interval provided with a sealing member 9 (described later). . Further, a terminal (not shown) that is electrically connected to a connection terminal (not shown) of the substrate 2 is provided on the back surface (lower surface) of the CPU 3, and this terminal is connected to the connection terminal of the substrate 2. Are electrically connected through solder bumps 8. A sealing member 9 for sealing between the solder bumps 8 is filled between the CPU 3 and the substrate 2.

  The sealing member 9 is made of a known sealing resin such as a phenol resin, an epoxy resin, or a polyimide resin. The sealing member 9 is formed by allowing the resin precursor described above to flow into the gap between the CPU 3 and the substrate 2 after the solder bumps 8 are formed and then curing.

  The 1st heat conductive member 4 is filled so that it may be interposed between CPU3 and the ceiling part 11 (after-mentioned) of the heat spreader 5 in the thickness direction. Specifically, the first heat conducting member 4 is directly laminated in a sheet shape on the upper surface of the CPU 3 and covers the upper surface of the CPU 3.

  The 1st heat conductive member 4 may be formed from the above-mentioned heat conductive member, or may be formed from well-known heat dissipation materials, such as silicone grease, an epoxy resin, and solder. Preferably, it is formed from the above-described heat conducting member.

  In order to provide the 1st heat conductive member 4, for example, above-mentioned material is apply | coated directly to the upper surface of CPU3 with a well-known application | coating method, and it heats at 50-180 degreeC after that, for example, and dries.

  Moreover, the 1st heat conductive member 4 can also be transcribe | transferred to the upper surface of CPU3 from the release sheet in which the 1st heat conductive member 4 was laminated | stacked.

  The thickness (thickness after drying) T1 of the first heat conducting member 4 formed in this way depends on the length (interval) between the upper surface of the CPU 3 and the lower surface of the heat spreader 5, but is, for example, 1.0 to 100 μm. Preferably, it is set in a range of about 3.0 to 50 μm.

  The heat spreader 5 is formed in a substantially U-shaped cross section with the lower part opened, and is disposed opposite to the CPU 3. The heat spreader 5 is made of a metal material having excellent thermal conductivity, such as nickel, copper, or aluminum. The heat spreader 5 is integrally provided with a ceiling portion 11 and leg portions 12 extending downward from the peripheral end portion of the ceiling portion 11.

  The ceiling part 11 is disposed opposite to the CPU 3 on the upper side with an interval at which the first heat conducting member 4 is provided. Moreover, the ceiling part 11 is arrange | positioned so that the 1st heat conductive member 4 may be included in planar view, and the lower surface of the planar view center part of the ceiling part 11 is contacting the upper surface of the 1st heat conductive member 4. FIG.

  The leg 12 is disposed so as to surround the first heat conducting member 4, the CPU 3, and the sealing member 9 in plan view, and the leg 12 is erected on the upper surface of the substrate 2.

  Thereby, a closed space 21 partitioned by the heat spreader 5 and the substrate 2 is formed inside the heat spreader 5, and the first heat conducting member 4, the CPU 3 and the sealing member 9 are accommodated in the closed space 21.

  The second heat conducting member 6 is filled so as to be interposed between the ceiling portion 11 of the heat spreader 5 and a base portion 13 (described later) of the heat sink 7. Specifically, the second heat conducting member 6 is directly laminated in a sheet shape on the upper surface of the ceiling portion 11 of the heat spreader 5 and covers the upper surface of the ceiling portion 11.

  In order to provide the second heat conductive member 6, for example, the above-described emulsion of the inorganic-polymer composite material is applied to the top surface of the ceiling portion 11 of the heat spreader 5 by a known coating method such as roll coating, screen coating, or gravure coating. Directly applied, and then dried by heating at 50 to 180 ° C., for example.

  Moreover, the 2nd heat conductive member 6 can also be transcribe | transferred to CPU3 from the release sheet in which the 2nd heat conductive member 6 was laminated | stacked.

  The release sheet on which the second heat conducting member 6 is laminated is, for example, directly applied to the known release sheet (for example, a polyester film) by the above-described inorganic-polymer composite emulsion by a known application method. Then, this is formed by, for example, drying by heating at 50 to 180 ° C. to form the second heat conductive member 6. In order to transfer the second heat conductive member 6, the upper surface of the ceiling portion 11 of the heat spreader 5 and the second heat conductive member 6 are brought into contact with each other, and then the release sheet is peeled off from the second heat conductive member 6. .

  The thickness (thickness after drying) T2 of the second heat conducting member 6 formed in this way is set to a range of, for example, about 1.0 to 100 μm, preferably about 3.0 to 50 μm.

  The heat sink 7 has a substantially comb shape in cross section, and is formed of a metal material having excellent thermal conductivity, such as nickel, copper, or aluminum. The heat sink 7 is integrally provided with a base 13 and a plurality of protrusions 14 protruding upward from the base 13.

  The base 13 is a sheet-like bottom plate of the heat sink 7, and the lower surface of the base 13 is in contact with the second heat conducting member 6.

  The protrusions 14 are formed in the shape of a bar (needle) that is long in the thickness direction, and are arranged to face each other at intervals in directions orthogonal to the thickness direction (the left-right direction and the depth direction in FIG. 1).

  In the microprocessor 1, the heat generated by the CPU 3 is released to the heat spreader 5 via the first heat conductive member 4, and then the heat released to the heat spreader 5 is released via the second heat conductive member 6. Then, the heat is released to the heat sink 7 and then the heat released to the heat sink 7 is released to the outside of the microprocessor 1.

  In particular, in the inorganic-polymer composite material forming the second heat conducting member 6, hydrophilic inorganic compounds are unevenly distributed on the surface of the polymer particles. Therefore, while maintaining the mechanical property of the polymer particle in the 2nd heat conductive member 6, it is excellent in both the heat conductivity of the 2nd heat conductive member 6, and adhesiveness.

  That is, since the second heat conducting member 6 is excellent in adhesiveness, it can be reliably adhered to the heat spreader 5 and the heat sink 7. Therefore, since they are securely in contact with each other at the interface between the heat spreader 5 and the second heat conducting member 6, the heat of the heat spreader 5 can be reliably conducted to the second heat conducting member 6. Further, since these are securely adhered at the interface between the second heat conducting member 6 and the heat sink 7, the heat conducted to the second heat conducting member 6 can be reliably conducted to the heat sink 7. As a result, the heat conducted to the heat spreader 5 can be efficiently released to the heat sink 7 by the second heat conducting member 6.

  Furthermore, since the second heat conducting member 6 itself is excellent in thermal conductivity, the heat conducted to the heat spreader 5 can be more efficiently released to the heat sink 7 by the second heat conducting member 6. .

  Therefore, it is possible to efficiently dissipate heat in the microprocessor 1.

  And since the 2nd heat conductive member 6 is excellent in adhesiveness, the outstanding heat dissipation can be ensured also by long-term use of the microprocessor 1. FIG.

  The above-described microprocessor 1 is used as an electronic device having excellent heat dissipation and reliability by using it in electronic devices such as notebook personal computers, desktop personal computers, servers, and workstations. can do.

  In order to further improve the thermal conductivity, a heat conductive layer 8 may be provided on the upper surface (front surface) and the lower surface (back surface) of the second heat conductive member 6 as shown by the phantom line in FIG. it can.

  The heat conductive layer 8 is a layer that is particularly excellent in heat conductivity, and is laminated on the entire upper surface and lower surface of the second heat conductive member 6. The heat conduction layer 8 on the upper surface side of the second heat conduction member 6 is interposed between the second heat conduction member 6 and the base 13, and the heat conduction layer 8 on the lower surface side of the second heat conduction member 6 is the second heat conduction member 6. It is interposed between the heat conducting member 6 and the ceiling portion 11.

  Examples of a material for forming the heat conductive layer 8 include potassium titanate, wollastonite, sepiolite, tin oxide (acicular tin oxide), magnesium hydroxide (acicular magnesium hydroxide), antimony-doped tin oxide, and copper oxide. , Nickel oxide, alumina, titanium oxide, zinc oxide, boron nitride, silicon nitride, copper, silver, nickel, gold, aluminum, solder, platinum, diamond, carbon black, carbon tube (carbon nanotube), carbon fiber, or polystyrene Examples thereof include a material mainly composed of composite conductive particles having a conductive layer coated on the surface of plastic particles.

  Examples of the method for forming the heat conductive layer 8 include a sputtering method, a vapor deposition method, a CVD method, and a plating method, in addition to known coating methods such as roll coating, screen coating, and gravure coating.

  The thickness of the heat conductive layer 8 is not specifically limited, Usually, it is 0.01-10 micrometers.

  Then, by providing such a heat conductive layer 8 between the second heat conductive member 6 and the ceiling portion 11 and between the second heat conductive member 6 and the base portion 13, the heat spreader 5 is conducted. Heat can be efficiently conducted to the second heat conducting member 6, and furthermore, the heat conducted to the second heat conducting member 6 can be efficiently released to the heat sink 7.

  In the above description, the heat conductive layer 8 is provided on both the upper surface and the lower surface of the second heat conductive member 6. For example, although not shown, either the upper surface or the lower surface of the second heat conductive member 6 is provided. It can also be provided only.

  Furthermore, although the heat conductive layer 8 is provided on the entire upper surface and lower surface of the second heat conductive member 6, for example, although not shown, only a part of the upper surface and the lower surface of the second heat conductive member 6 are provided. It can also be provided.

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

Example 1
A. Preparation of emulsion of inorganic-polymer composite (aqueous dispersion preparation process)
20 parts by weight of hydrophilic boron nitride particles (primary particle diameter 20 nm) were added to 715 parts by weight of water, and this was treated with an ultrasonic homogenizer for 3 minutes to obtain an aqueous dispersion.

(Monomer emulsion preparation process)
Isostearyl acrylate 100 parts by weight, hexadecane 5 parts by weight, initiator (dimethyl 2,2′-azobis (2-methylpropionate), oil-soluble azo initiator, trade name: V-601, Wako Pure Chemical Industries, Ltd. (Manufactured) 0.25 parts by weight were mixed to prepare an oil phase liquid.

  Subsequently, the oil phase liquid and the aqueous dispersion were mixed, and stirred and forcedly emulsified at 6000 (1 / min) for 1 minute using a TK homomixer (manufactured by Primex) to prepare a monomer pre-emulsion.

  Next, this monomer pre-emulsion was treated with a high-pressure homogenizer (PANDA 2K) for 2 passes at a pressure of 100 MPa, and 20 wt% dispersant liquid (polymer dispersant, trade name: Charol AN-103P, Daiichi 5 parts by weight (manufactured by Kogyo Seiyaku Co., Ltd.) (1 part by weight in solid content) was added to obtain a monomer emulsion.

(Polymerization process)
Charge the prepared monomer emulsion into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, and then purge the reaction vessel with nitrogen, then raise the temperature to 70 ° C. and polymerize for 3 hours to solidify the solid content. An emulsion of an inorganic-polymer composite material having a concentration of 20% was obtained.
B. Preparation of heat conduction member The obtained emulsion of inorganic-polymer composite material was applied on a release film (MRF38, polyester film, manufactured by Toray Industries, Inc.) so that the thickness after drying was 25 μm, and then hot air circulation was performed. By drying at 120 ° C. for 5 minutes in a type oven, and then bonding a release film (MRF38, polyester film, manufactured by Toray Industries, Inc.) to the other side (the side opposite to the one side on which the release film is laminated) A film (sheet) -like heat conducting member was produced.

  It was confirmed with a dial gauge that the thickness of the heat conducting member after drying was 25 μm.

  This heat conducting member was formed from an inorganic-polymer composite material in which boron nitride having a maximum length (primary particle diameter) of 20 nm was unevenly distributed on the surface of the polymer particles.

Example 2
A. Preparation of Inorganic-Polymer Composite Emulsion In the aqueous dispersion preparation step, the same procedure as in Example 1 was carried out except that the blending part of water was changed to 942 parts by weight and the blending part of boron nitride particles was changed to 60 parts by weight. In the monomer emulsion preparation step, Example was used except that 0.03 parts by weight of 3-methacryloyloxypropyl-trimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) was further used. In the same manner as in No. 1, an aqueous dispersion was prepared, and then a monomer emulsion was prepared, followed by polymerization to obtain an inorganic-polymer composite emulsion having a solid content of 30%.
B. Production of Heat Conducting Member A film-like heat conducting member was produced in the same manner as in Example 1.

  This heat conducting member was formed from an inorganic-polymer composite material in which boron nitride having a maximum length (primary particle diameter) of 20 nm was unevenly distributed on the surface of the polymer particles.

Example 3
A. Preparation of emulsion of inorganic-polymer composite (aqueous dispersion preparation process)
84 parts by weight of ATO (antimony-doped tin oxide) aqueous dispersion (SN-100S, solid content concentration 17.9%, manufactured by Ishihara Sangyo Co., Ltd.), 368 parts by weight of water, and 3-methacryloyl 4.5 parts by weight of oxypropyl-trimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and stirred at room temperature for 20 hours. This was adjusted to pH 4.0 with a 5% aqueous acetic acid solution to prepare an aqueous dispersion.

(Monomer emulsion preparation process)
In an aqueous dispersion, 100 parts by weight of methyl methacrylate, 3 parts by weight of hexadecane, 0.2 part by weight of initiator (azobisisobutyronitrile), 20% by weight emulsifier liquid (anionic non-reactive emulsifier, trade name: High Tenol LA-16, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.25 parts by weight (0.05 parts by weight in solids) was added, and 6000 (1 / min) for 1 minute using a TK homomixer (Primics). The mixture was stirred and forcedly emulsified to prepare a monomer pre-emulsion. Subsequently, this monomer pre-emulsion was subjected to one pass treatment at a pressure of 150 MPa using a high-pressure homogenizer (Nanomizer, manufactured by Yoshida Kikai Kogyo Co., Ltd.) to obtain a monomer emulsion.

(Polymerization process)
The prepared monomer emulsion was charged into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirrer, and then the reaction vessel was purged with nitrogen, then heated to 70 ° C. and polymerized for 3 hours to form a solid. An emulsion of an inorganic-polymer composite material having a partial concentration of 20% was obtained.
B. Production of Heat Conducting Member A film-like heat conducting member was produced in the same manner as in Example 1.

  This heat conducting member was formed of an inorganic-polymer composite material in which antimony-doped tin oxide having a maximum length (primary particle diameter) of 20 nm was unevenly distributed on the surface of polymer particles.

Example 4
A. Preparation of Inorganic-Polymer Emulsion Emulsion In the aqueous dispersion preparation step, the number of blended parts of the ATO aqueous dispersion was changed to 50 parts by weight and the blended number of water was changed to 486 parts by weight. -An aqueous dispersion was prepared in the same manner as in Example 3 except that the amount of methacryloyloxypropyl-trimethoxysilane was changed to 9.1 parts by weight, and then a monomer emulsion was prepared. Was polymerized to obtain an inorganic-polymer composite emulsion having a solid content of 18%.
B. Production of Heat Conducting Member A film-like heat conducting member was produced in the same manner as in Example 1.

  This heat conducting member was formed of an inorganic-polymer composite material in which antimony-doped tin oxide having a maximum length (primary particle diameter) of 20 nm was unevenly distributed on the surface of polymer particles.

Example 5
A. Preparation of Inorganic-Polymer Emulsion Emulsion In the aqueous dispersion preparation step, the blending number of the ATO aqueous dispersion was changed to 70 parts by weight and the blending number of water was changed to 486 parts by weight. After adjusting the pH to 4.0 with a 1% aqueous acetic acid solution, 2.2 parts by weight of a dispersant solution (polycarboxylic acid-based dispersant, trade name: Charol AN-103P, solid concentration 45%, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Except for further addition of 1 part by weight of solid content), an aqueous dispersion was prepared in the same manner as in Example 3 and then a monomer emulsion was prepared, followed by polymerization to obtain a solid content concentration. An emulsion of 18% inorganic-polymer composite was obtained.
B. Production of Heat Conducting Member A film-like heat conducting member was produced in the same manner as in Example 1.

  This heat conducting member was formed of an inorganic-polymer composite material in which antimony-doped tin oxide having a maximum length (primary particle diameter) of 20 nm was unevenly distributed on the surface of polymer particles.

Example 6
A. Preparation of Inorganic-Polymer Composite Emulsion In the aqueous dispersion preparation step, after adjusting the pH to 4.0 with a 5% aqueous acetic acid solution, a 20% by weight dispersant liquid (polymer dispersant, trade name: Charol AN-103P, No. 1) A water dispersion was prepared in the same manner as in Example 3 except that 5 parts by weight (manufactured by Ichi Kogyo Seiyaku Co., Ltd.) (1 part by weight as a solid content) was further added. A monomer emulsion was prepared in the same manner as in Example 3 except that butyl acrylate was used instead of methyl, and this was then polymerized to obtain an emulsion of an inorganic-polymer composite material having a solid content concentration of 20%. Got.
B. Production of Heat Conducting Member A film-like heat conducting member was produced in the same manner as in Example 1.

  This heat conducting member was formed of an inorganic-polymer composite material in which antimony-doped tin oxide having a maximum length (primary particle diameter) of 20 nm was unevenly distributed on the surface of polymer particles.

Example 7
A. Preparation of Inorganic-Polymer Composite Emulsion In the aqueous dispersion preparation step, after adjusting to pH 4.0 with 5% acetic acid aqueous solution, the aqueous dispersion was further stirred and mixed for 20 hours in the same manner as in Example 3, An aqueous dispersion was prepared, and subsequently a monomer emulsion was prepared in the same manner as in Example 3 except that butyl acrylate was used instead of methyl methacrylate in the monomer emulsion preparation step. By polymerizing, an inorganic-polymer composite emulsion having a solid concentration of 20% was obtained.
B. Production of Heat Conducting Member A film-like heat conducting member was produced in the same manner as in Example 1.

  This heat conducting member was formed of an inorganic-polymer composite material in which antimony-doped tin oxide having a maximum length (primary particle diameter) of 20 nm was unevenly distributed on the surface of polymer particles.

Comparative Example 1
A. Preparation of polymer emulsion (aqueous dispersion preparation process)
To 106 parts by weight of water, add 20% by weight of an emulsifier solution (anionic non-reactive emulsifier, trade name: Haitenol LA-16, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 15 parts by weight (solid content concentration: 3 parts by weight) An aqueous dispersion was prepared.

(Monomer emulsion preparation process)
100 parts by weight of butyl acrylate, 5 parts by weight of hexadecane, 0.03 part by weight of 3-methacryloyloxypropyl-trimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.), initiator (dimethyl 2,2′-azobis (2- Methyl propionate), oil-soluble azo initiator, trade name: V-601, manufactured by Wako Pure Chemical Industries, Ltd.) 0.25 parts by weight were mixed to prepare an oil phase liquid.

  Next, the oil phase liquid and the aqueous dispersion were mixed, and the mixture was forcibly emulsified by stirring at 6000 (1 / min) for 1 minute using a TK homomixer (manufactured by Primics) to prepare a monomer pre-emulsion. . Next, this monomer pre-emulsion was treated for 2 passes at a pressure of 100 MPa using a high-pressure homogenizer (PANDA 2K) to obtain a monomer emulsion.

(Polymerization process)
Charge the prepared monomer emulsion into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, and then purge the reaction vessel with nitrogen, then raise the temperature to 70 ° C. and polymerize for 3 hours to solidify the solid content. A polymer emulsion with a concentration of 50% was obtained.
B. Production of Heat Conducting Member A film-like heat conducting member was produced in the same manner as in Example 1.

  This heat conducting member was formed from a polymer in which inorganic compounds were not unevenly distributed on the surface of the polymer particles.

Comparative Example 2
A. Preparation of emulsion of inorganic-polymer composite (monomer emulsion preparation process)
100 parts by weight of butyl acrylate, 3 parts by weight of hexadecane, 0.2 part by weight of initiator (azobisisobutyronitrile), 20% by weight emulsifier liquid (anionic non-reactive emulsifier, trade name: Haitenol LA-16, 1 part by weight (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 part by weight (0.2 parts by weight in solids) and 309 parts by weight of water were added, and the mixture was stirred at 6000 (1 / min) for 1 minute using a homogenizer (manufactured by Primix). A monomer pre-emulsion was prepared by forced emulsification. Subsequently, this monomer pre-emulsion was subjected to one pass treatment at a pressure of 150 MPa using a high-pressure homogenizer (Nanomizer, manufactured by Yoshida Kikai Kogyo Co., Ltd.) to obtain a monomer emulsion.

(Polymerization process)
By charging the prepared monomer dispersion in a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, and then substituting the reaction vessel with nitrogen, the temperature was raised to 70 ° C. and polymerization was performed for 3 hours. An emulsion of a water-dispersed resin having a solid content concentration of 23% was obtained.

(Inorganic compound aqueous dispersion blending process)
After the polymerization step, 75 parts by weight of an aqueous dispersion (SN-100S, solid content concentration 17.9%, manufactured by Ishihara Sangyo Co., Ltd.) is added to the emulsion and stirred to obtain an inorganic-polymer composite. An emulsion of the material was obtained.
B. Production of Heat Conducting Member A film-like heat conducting member was produced in the same manner as in Example 1.

  This heat conducting member was formed from an inorganic-polymer composite material in which antimony-doped tin oxide having a maximum length (primary particle diameter) of 20 nm was uniformly present over the entire polymer particles (that is, the surface and the inside).

  Abbreviations of each component in the formulation of Table 1 will be described below.

BA: butyl acrylate
ISTA: isostearyl acrylate MMA: methyl methacrylate KBM-503: 3-methacryloyloxypropyl-trimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd. V-601: dimethyl 2,2′-azobis (2-methylpropionate), sum BN: Boron nitride particles (hydrophilic), primary particle size: 20 nm, manufactured by Kojun Pharmaceutical Co., Ltd.
SN-100S: ATO aqueous dispersion, solid content concentration 17.9%, manufactured by Ishihara Sangyo Co., Ltd. LA-16: Hightenol LA-16 (trade name), 20% by weight emulsifier liquid, anionic non-reactive emulsifier, first Sharol AN-103P manufactured by Kogyo Seiyaku Co., Ltd .: Trade name, polycarboxylic acid-based dispersant solution, solid content concentration 45%, manufactured by Daiichi Kogyo Seiyaku (Evaluation)
1) Median Diameter of Inorganic-Polymer Composite Material Regarding the inorganic-polymer composite materials in Examples 1 to 7 and Comparative Examples 1 and 2, a laser diffraction scattering type particle size distribution system (LS 13 320, laser light source: laser diode and tungsten halogen lamp) The average median diameter was measured using a wavelength of 450 to 900 nm, manufactured by Beckman Coulter. The results are shown in Table 2.

As can be seen from Table 2, the median diameter of the polymer particles of the inorganic-polymer composite materials of Examples 1 to 7 (and Comparative Examples 1 and 2) is in the range of 0.05 to 100 μm.
2) SEM observation The emulsion of the inorganic-polymer composite material obtained in Examples 2 to 6 was diluted with water, dropped onto a sample stage, and then dried at 30 ° C for 30 minutes. Subsequently, after performing Pt-Pd sputtering for 5 seconds, SEM observation was performed using FE-SEM (S-4800 made by HITACHI) having an acceleration voltage of 0.1 to 1 kV.

Image processing diagrams of these SEM photographs are shown in FIGS.
3) TEM observation The emulsion of the inorganic-polymer composite material obtained in Example 7 was diluted with water, one drop was dropped on a TEM sample table with a carbon film, dried, and then a Hitachi transmission electron microscope Hitachi H- Using 7650, observation was performed at an acceleration voltage of 100 kV.

  Further, the emulsion of the inorganic-polymer composite material obtained in Comparative Example 2 was embedded in an epoxy resin, and then dyed by treating in an aqueous 2% ruthenic acid solution for 3 hours, and this was treated with an ultramicrotome (Ultracut). S, manufactured by Leica Co.) to a thickness of about 80 nm, and then a cross section of the ultrathin slice was observed at an acceleration voltage of 100 kV using a Hitachi transmission electron microscope Hitachi H-7650.

Image processing diagrams of these TEM photographs are shown in FIGS. 8 and 9, respectively.
4) Adhesiveness The release film (MRF38) on one side was peeled off from the heat conducting members obtained in Examples 1 to 7 and Comparative Examples 1 and 2, and this heat conducting member was attached to a PET film having a thickness of 38 μm. After matching, this is cut into a size of 25 mm length × 25 mm width, and then a release film (MRF38) on the other side (release film on the opposite side of the one side on which the PET film is bonded). After peeling, this heat conducting member was affixed to the surfaces of the silicon wafer and Ni plating foil (adhered body), respectively. Thereafter, the heat conduction member was pressed against each adherend by reciprocating a 2 kg rubber roller once, and then left in an autoclave at 50 ° C. and 0.5 Mpa for 15 minutes. Then, it cooled to 25 degreeC and evaluated the adhesiveness with respect to each to-be-adhered body of a heat conductive member. The results are shown in Table 3.

In the adhesive evaluation column in Table 3, the case where the heat conducting member was stuck to the adherend was indicated by ◯, and the case where it was not stuck was indicated by ×.
5) Heat dissipation As shown in FIG. 2, the release film (MRF38) on one side was peeled from the heat conducting member (second heat conducting member) 6 obtained in Examples 1 to 7 and Comparative Examples 1 and 2. The heat conducting member 6 is transferred to a bottom surface (8 mm × 12 mm) of a ceramic heating element 23 (rated 2 W, resistance 100 Ω, width 8 mm × length 12 mm × height 20 mm) provided with an electrode 24 on the upper surface. Next, the release film (MRF38) on the other side (the release film on the opposite side of the one side to which the heating element 23 is attached) is peeled off, and then the heat conducting member 6 is coated with 50 mm × 50 mm. A sample for evaluating heat dissipation was prepared by bonding an aluminum plate 22 (thickness 0.2 mm).

  Next, a voltage of 1.7 V (current 17 mA) was applied to the electrode 24 of the heating element 23, and then the temperature inside the heating element 23 was measured after reaching a steady state (after about 20 minutes). The results are shown in Table 3.

  From Table 3, it can be seen that the samples of Examples 1 to 7 have good heat dissipation and the temperature of the heating element 23 is kept low. On the other hand, it can be seen that in the samples of Comparative Examples 1 and 2, the temperature of the heating element 23 is high and the heat dissipation to the aluminum plate 22 is not sufficient.

6 Second heat conduction member (adhesive heat conduction member)

Claims (11)

  It is made of an inorganic-polymer composite material in which hydrophilic inorganic compounds having a maximum length or a primary average particle diameter of 1-1000 nm are unevenly distributed on the surface of polymer particles having a volume-based median diameter of 0.05-100 μm. An adhesive heat conductive member characterized by the above.   The adhesive heat conductive member according to claim 1, wherein the polymer particles are obtained by polymerizing an ethylenically unsaturated monomer.   The adhesive heat conductive member according to claim 2, wherein the ethylenically unsaturated monomer contains a (meth) acrylic acid alkyl ester.   The adhesive heat conductive member according to claim 3, wherein the ethylenically unsaturated monomer further contains a copolymerizable vinyl monomer copolymerizable with the alkyl (meth) acrylate.   The adhesive heat conductive member according to claim 4, wherein a blending ratio of the copolymerizable vinyl monomer is 40 parts by weight or less with respect to 100 parts by weight of the ethylenically unsaturated monomer.   The adhesive heat conductive member according to any one of claims 1 to 5, wherein the adhesive heat conductive member is formed in a film shape having a thickness of 1.0 to 100 µm.   The adhesive heat conductive member according to claim 1, wherein a content ratio of the inorganic compound is 4 to 200 parts by weight with respect to 100 parts by weight of the polymer particles.   The adhesive heat conducting member according to claim 1, wherein the polymer particles are water-dispersed polymer particles.   The adhesive heat conductive member according to any one of claims 1 to 8, wherein the inorganic compound is a hydrophilic inorganic compound having a bulk shape, a needle shape, or a plate shape.   The adhesive heat conductive member according to claim 1, wherein the inorganic compound is supported in a dispersed state on the surface of the polymer particles. A step of dispersing a hydrophilic inorganic compound in water to prepare an aqueous dispersion of the inorganic compound;
Blending the aqueous dispersion and the ethylenically unsaturated monomer, and emulsifying the ethylenically unsaturated monomer to prepare a monomer emulsion;
Adding a surfactant to at least one of water, the aqueous dispersion, the ethylenically unsaturated monomer, and the monomer emulsion;
And a step of polymerizing the ethylenically unsaturated monomer in the monomer emulsion. A method for producing an adhesive heat conductive member.