JPWO2020105215A1 - High withstand voltage heat dissipation insulating resin composition and electronic components using it - Google Patents

Abstract

Provided is a high withstand voltage heat dissipation insulating resin composition which has high thermal conductivity, good heat dissipation, can prevent deterioration of withstand voltage characteristics, and does not require machining such as pressure molding or vacuum pressing. A high withstand voltage heat dissipation insulating resin composition containing (A) high thermal conductive particles and (B) a curable resin, wherein the volume occupancy of the (A) high thermal conductive particles is high withstand voltage heat dissipation. The specific surface area of the (A) high thermal conductive particles measured by the (A-1) BET method is 0.2 to 0.6 m, which is 60% by volume or more based on the total solid content of the insulating resin composition. ^{It contains 2} / g high thermal conductive particles and (A-2) high thermal conductive particles with a specific surface area of 6.0 to 12.5 m 2 / g measured by the BET method, and all of the (A) high thermal conductive particles described above. ^{The high thermal conductive particles having a specific surface area of 6.0 to 12.5 m 2} / g measured by the (A-2) BET method are 5 to 16% by weight based on the weight.

Description

The present invention relates to a heat-dissipating insulating resin composition having excellent withstand voltage, and electronic components using the same. More specifically, the present invention has high withstand-voltage heat-dissipating insulation having excellent withstand voltage characteristics without lowering thermal conductivity. The present invention relates to a sex resin composition and electronic components such as a printed wiring board using the same.

_{In recent years, reduction of CO 2} has been required as a measure against global warming, and the development of vehicles using high-power motors such as electric vehicles and hybrid vehicles has been promoted as a measure against exhaust gas of automobiles. When supplying power from a battery to a motor, power transistors and power diodes used to convert to high voltage and high current have a problem of heat generation during operation, and in particular, conversion to higher voltage is possible. It is expected that this heat generation problem will become more prominent in the next generation of electric vehicles planned. Therefore, there is a demand for further improvement in high thermal conductivity and high heat dissipation.

As a printed wiring board with good heat dissipation, for example, in Patent Document 1, a metal plate such as copper or aluminum is used, and an electrically insulating layer such as a prepreg or a thermosetting resin composition is provided on one or both sides of the metal plate. A metal base substrate that forms a circuit pattern through the invention is disclosed.

Further, for example, Patent Document 2 contains a high thermal conductive resin cured product containing a certain large particle size filler in a certain ratio, and Patent Document 3 contains a high heat containing a certain small particle size filler in a certain ratio. The conductive resin cured product is disclosed.

Japanese Unexamined Patent Publication No. 6-224561 Japanese Unexamined Patent Publication No. 2014-189701 Japanese Unexamined Patent Publication No. 2014-193565

However, in the metal base substrate according to the invention described in Patent Document 1, it is necessary to make the insulating layer thin because the thermal conductivity of the electrically insulating layer is low, and as a result, the withstand voltage characteristic of the electrically insulating layer is deteriorated. There was a problem such as.

Further, in the high thermosetting resin cured product according to the inventions described in Patent Documents 2 and 3, fine bubbles (microbubbles) generated in the voids of the filler also deteriorate the withstand voltage characteristics. Therefore, in order to prevent this and to close-pack the high thermal conductive particles, machining such as pressure molding or vacuum pressing is required, which is troublesome and has a problem of poor workability.

The present invention has been made in view of the above problems, and its main purpose is to have high thermal conductivity, good heat dissipation, prevent deterioration of withstand voltage characteristics, and perform machining such as pressure molding or vacuum pressing. It is an object of the present invention to provide an unnecessary high withstand voltage heat dissipation insulating resin composition.

Another object of the present invention is to provide an electronic component having a cured product obtained by thermosetting and / or photocuring the high withstand voltage heat dissipation insulating resin composition.

The inventor has conducted diligent research toward the realization of the above-mentioned purpose. As a result, together with (B) the curable resin, (A-1) high thermal conductive particles having ^{a specific surface area of 0.2 to 0.6 m 2} / g measured by the BET method as (A) high thermal conductive particles were obtained. Closest packing is performed by blending (A-2) high thermal conductive particles having a specific surface area of 6.0 to 12.5 m ² / g measured by the BET method so that the blending amount of these particles is a constant ratio. It has been found that the withstand voltage characteristics can be improved without lowering the thermal conductivity, and the present invention has been completed.

That is, the high withstand voltage heat dissipation insulating resin composition of the present invention is a high withstand voltage heat dissipation insulating resin composition containing (A) high thermal conductive particles and (B) curable resin. A) The volume occupancy of the high thermal conductive particles is 60% by volume or more with respect to the total solid content of the high withstand voltage heat-dissipating insulating resin composition, and the (A) high thermal conductive particles are (A-1). ) ratio was measured by the BET method surface area and high thermal conductivity particles ^{0.2~0.6m 2 / g (a-2} ) the specific surface area measured by the BET method of 6.0~12.5m ² / g high heat ^{High thermal conductive particles containing conductive particles and having a specific surface area of 6.0 to 12.5 m 2} / g measured by the (A-2) BET method with respect to the total weight of the (A) high thermal conductive particles. Is 5 to 16% by weight. The solid content of the composition refers to the composition obtained by removing the organic solvent.

The high withstand voltage heat-dissipating insulating resin composition of the present invention preferably further contains (C) an organic solvent, and is preferably a coating type.

In the high withstand voltage heat dissipation insulating resin composition of the present invention, it is preferable that the (A) high thermal conductive particles are aluminum oxide particles.

In the high thermal conductivity heat-dissipating insulating resin composition of the present invention, the (A) high thermal conductive particles have a high thermal conductivity of 0.2 to 0.6 m ² / g as measured by the (A-1) BET method. It is preferable that the particles are composed only of the sex particles and the high thermal conductive particles having a specific surface area of 6.0 to 12.5 m ^{2 / g measured by the (A-2) BET method.}

The high withstand voltage heat-dissipating insulating resin composition of the present invention contains at least one of (B-1) a thermosetting resin and (B-2) a photocurable resin as the (B) curable resin. It is preferable to do so.

The high withstand voltage heat-dissipating insulating resin composition of the present invention may contain an epoxy compound and / or an oxetane compound as the (B-1) thermosetting resin, and further contain a curing agent and / or a curing catalyst. preferable.

The high withstand voltage heat-dissipating insulating resin composition of the present invention contains a compound having one or more ethylenically unsaturated bonds in one molecule as the (B-2) photocurable resin, and further starts photopolymerization. It is preferable to contain an agent.

The cured product of the present invention is characterized by being obtained by curing the high withstand voltage heat-dissipating insulating resin composition. The electronic component of the present invention is characterized by having the cured product. The electronic component of the present invention preferably has an insulating layer and / or a solder resist layer formed by a cured product obtained by thermally curing and / or photocuring the high withstand voltage heat-dissipating insulating resin composition. ..

According to the present invention, there is provided a high withstand voltage heat dissipation insulating resin composition which has high thermal conductivity, good heat dissipation, can prevent deterioration of withstand voltage characteristics, and does not require machining such as pressure molding or vacuum pressing. be able to. Further, electronic components such as a printed wiring board in which an insulating layer and / or a solder resist layer is formed by a cured product obtained by thermosetting and / or photocuring the high withstand voltage heat dissipation insulating resin composition. Can be provided. The composition of the present invention can also be provided for filling holes such as via holes and through holes of a printed wiring board.

The high withstand voltage heat dissipation insulating resin composition of the present invention is a high withstand voltage heat dissipation insulating resin composition containing (A) high thermal conductive particles and (B) curable resin, and the above (A). The volume occupancy of the high thermal conductive particles is 60% by volume or more with respect to the total solid content of the high withstand voltage heat-dissipating insulating resin composition, and the (A) high thermal conductive particles are (A-1) BET. specific surface area measured by the law and the high thermal conductivity particles ^{0.2~0.6m 2 / g (a-2} ) high thermal conductivity ratio were measured by the BET method surface area of 6.0~12.5m ² / g ^{5 high thermal conductive particles containing particles and having a specific surface area of 6.0 to 12.5 m 2} / g measured by the (A-2) BET method with respect to the total weight of the (A) high thermal conductive particles. It is characterized in that it is ~ 16% by weight. In the "BET method" for measuring the specific surface area in the present invention, for example, a fully automatic BET specific surface area measuring device Massorb HM-1201 manufactured by Mountech Co., Ltd. is used, and the measurement is performed by the BET one-point method. Yes, but not limited to this.

In the present invention, as (A) highly thermally conductive particles, particles having a specific surface area of 0.2 to 0.6 m ² / g measured by the (A-1) BET method and (A-2) the specific surface area measured by the BET method. By using particles of 6.0 to 12.5 m ² / g in combination and containing 60% by volume or more of the total amount of the particles with respect to the total solid content of the high withstand voltage heat dissipation insulating resin composition, heat conduction The rate is increased and sufficient thermal conductivity as a heat radiating material is obtained.

(A-1) It is possible to increase the thermal conductivity by containing high thermal conductive particles having a specific surface area of 0.2 to 0.6 m ^{2 / g measured by the BET method, but this alone makes it possible to increase the withstand voltage.} Is low and is not suitable for insulating materials under high voltage. ^{Therefore, in the present invention, high thermal conductive particles having a specific surface area of 6.0 to 12.5 m 2} / g measured by the (A-2) BET method are provided at a constant ratio ((A) with respect to the total weight of the high thermal conductive particles. The withstand voltage characteristics are improved by blending the above 5 to 16% by weight). (A-2) The present invention is prepared by blending high thermal conductive particles having a specific surface area of 6.0 to 12.5 m ² / g measured by the BET method in a fixed ratio, and preferably containing (C) an organic solvent. The high withstand voltage heat-dissipating insulating resin composition can be suitably used as a paint, and by applying it thinly as a paint, fine bubbles adhering to the voids of the filler can be removed. Therefore, in the high withstand voltage heat dissipation insulating resin composition of the present invention, high withstand voltage and (A) high heat can be achieved without performing labor-intensive and poor workability machining such as pressure molding and vacuum pressing. By densely filling the conductive particles, it is possible to achieve both high thermal conductivity, that is, high heat dissipation.

If the specific surface area measured by the BET method is between (A-1) and (A-2) ^{and further contains high thermal conductive particles of 1.0 to 1.8 m 2} / g, the withstand voltage does not improve. In addition, the specific surface area measured by the BET method is larger than that of (A-2), and ^{the high thermal conductivity particles of 55 m 2} / g or more have high thermal conductivity, and it is difficult to reduce the voids of the filler. Both withstand voltage characteristics decrease. Therefore, in the present invention, (A) highly thermally conductive particles are measured by the (A-1) BET method with particles having a specific surface area of 0.2 to 0.6 m ² / g measured by the (A-1) BET method. It is preferable that the specific surface area is ^{only 6.0 to 12.5 m 2} / g, while (A) the specific surface area measured by the BET method is 6.0 to 0 as the highly thermally conductive particles. When only 12.5 m ² / g high thermal conductive particles are used, the withstand voltage characteristics are significantly deteriorated as compared with the present invention. Also, (A-1) ratio was measured by the BET method surface area and particle ^{0.2~0.6m 2 / g (A-2} ) ratio was measured by the BET method surface area of 6.0~12.5m ² / When the particles of g are not used at all, the thermal conductivity becomes very low and the heat-dissipating insulating resin composition does not have the characteristics.

Hereinafter, each component of the high withstand voltage heat dissipation insulating resin composition of the present invention will be described in detail.

The (A) high thermal conductive particles of the present invention have a volume occupancy of 60% by volume or more with respect to the total solid content of the high withstand voltage heat dissipation insulating resin composition, and the (A) high thermal conductive particles described above. However, the specific surface area measured by the (A-1) BET method is 0.2 to 0.6 m ² / g, and the specific surface area measured by the (A-2) BET method is 6.0 to 12. It contains 5 m ² / g of high thermal conductive particles, and the specific surface area measured by the (A-2) BET method is 6.0 to 12.5 m ² / with respect to the total weight of the (A) high thermal conductive particles. It is characterized in that the high thermal conductive particles of g are 5 to 16% by weight.

In the present invention, as the material of the (A) high thermal conductive particles, known and commonly used materials can be used as long as they have high thermal conductivity. For example, aluminum oxide _{(Al 2 O} 3), silica _(SiO 2), silicon carbide (SiC), zirconia _(ZrO 2), titanium oxide _(TiO 2), magnesium oxide (MgO), mullite _{(3Al 2} O 3 · 2SiO _2), zircon (especially _ZrO 2 · _SiO 2) of the cordierite _{(2MgO · 2Al 2 O 3 ·} 5SiO 2), silicon nitride _{(Si 3 N} 4), manganese oxide _(MnO 2), iron oxide ( Fe ₂ O ₃ ), cobalt oxide (CoO) and the like can be used.

Among these, aluminum oxide is preferable because it is chemically stable and has excellent insulating properties, and spherical particles can moderate the increase in viscosity at the time of high filling and are suitable for close-packing, so that they are spherically oxidized. It is preferable to use aluminum. As a commercially available product of spherical aluminum oxide particles, DAW-03 (Electrochemical Industry Co., Ltd.) ^{is a highly thermally conductive particle having a specific surface area of 0.2 to 0.6 m 2} / g measured by the (A-1) BET method. Made by BET method, specific surface area 0.5 to 0.6 m ² / g), DAW-05 (manufactured by Denki Kagaku Kogyo Co., Ltd., measured by BET method specific surface area 0.4 to 0.5 m ² / g) ), DAW-07 (manufactured by Electrochemical Industry Co., Ltd., specific surface area measured by BET method 0.4 m ² / g), DAW-45 (manufactured by Electrochemical Industry Co., Ltd., specific surface area measured by BET method 0. 2m ² / g), DAW-70 (manufactured by Denki Kagaku Kogyo Co., Ltd., specific surface area measured by the BET method 0.2m ² / g), but (A-2) specific surface area measured by the BET method is 6.0. As high thermal conductive particles of ~ 12.5 m ² / g, AO-509 (manufactured by Admatech, specific surface area measured by BET method 6.5-9.0 m ² / g), ASFP-20 (Electrochemical Industry Co., Ltd.) ), Specific surface area measured by BET method 10-12 m ² / g), ASUSP-25 (manufactured by Denki Kagaku Kogyo Co., Ltd., specific surface area measured by BET method 8-10 m ² / g), ASFP-40 (Electricity) ^{Specific surface area 6 to 8 m 2} / g) manufactured by Kagaku Kogyo Co., Ltd. and measured by the BET method can be mentioned.

Further, the (A) highly thermally conductive particles of the present invention were measured by the (A-1) BET method and the particles having ^{a specific surface area of 0.2 to 0.6 m 2 / g measured by the (A-1) BET method.} High filling can be achieved by satisfying the condition of particles having a specific surface area of 6.0 to 12.5 m ^{2 / g.}

The highly thermally conductive particles (A) of the present invention are preferably surface-treated with a coupling agent such as a silane coupling agent in terms of improving low water absorption, thermal impact resistance and crack resistance of the cured product. As the coupling agent, a silane-based, titanate-based, aluminate-based, zircoaluminate-based coupling agent, or the like can be used. Of these, a silane-based coupling agent is preferable. Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminomethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) -3-amino. Propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epyl) Cyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned, and these can be used alone or in combination.
In these coupling agents, the surface-untreated (A) high thermal conductive particles and the coupling agent may be separately blended, and the (A) high thermal conductive particles may be surface-treated in the composition. It is preferable that (A) the coupling agent is immobilized on the surface of the highly thermally conductive particles in advance by adsorption or reaction. In this case, the amount of the coupling agent used for the surface treatment and the surface treatment method are not particularly limited.

In the present invention, it is preferable that the (B) curable resin contains at least one of (B-1) a thermosetting resin and (B-2) a photocurable resin.

Examples of the (B-1) thermosetting resin include resins that are cured by heating and exhibit electrical insulation, such as epoxy resin, oxetane resin, melamine resin, and silicon resin. In particular, in the present invention, an epoxy compound. A thermosetting resin of and / or an oxetane compound can be preferably used, in which case a curing agent and / or a curing catalyst is further preferred.

As the epoxy compound, a known and commonly used compound can be used as long as it is a compound having one or more, preferably two or more epoxy groups in one molecule. For example, bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3 -Diglycidyl ether, biphenyl-4,4'-diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol or propylene glycol diglycidyl ether, sorbitol polyglycidyl ether, tris (2,3-epoxypropyl) Examples thereof include compounds having two or more epoxy groups in one molecule, such as isocyanurate and triglycidyltris (2-hydroxyethyl) isocyanurate. Further, a monoepoxy compound such as butyl glycidyl ether, phenyl glycidyl ether, or glycidyl (meth) acrylate may be added as long as the cured coating film characteristics are not deteriorated. Further, these can be used alone or in combination of two or more types according to the demand for improving the characteristics of the coating film.

（式中、Ｒ^１は、水素原子又は炭素数１〜６のアルキル基を示す。）
オキセタン環を含有する化合物であり、具体的な化合物としては、３−エチル−３−ヒドロキシメチルオキセタン（東亞合成（株）製の商品名 ＯＸＴ−１０１）、３−エチル−３−（フェノキシメチル）オキセタン（東亞合成（株）製の商品名 ＯＸＴ−２１１）、３−エチル−３−（２−エチルヘキシロキシメチル）オキセタン（東亞合成社製の商品名 ＯＸＴ−２１２）、１，４−ビス｛［（３−エチル−３−オキセタニル）メトキシ］メチル｝ベンゼン（東亞合成社製の商品名 ＯＸＴ−１２１）、ビス（３−エチル−３−オキセタニルメチル）エーテル（東亞合成社製の商品名 ＯＸＴ−２２１）などが挙げられる。さらに、フェノールノボラックタイプのオキセタン化合物なども挙げられる。In addition, the oxetane compound has the following general formula (I), as shown in the following general formula (I).

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)
It is a compound containing an oxetane ring, and specific compounds include 3-ethyl-3-hydroxymethyloxetane (trade name OXT-101 manufactured by Toa Synthetic Co., Ltd.) and 3-ethyl-3- (phenoxymethyl). Oxetan (trade name OXT-211 manufactured by Toa Synthetic Co., Ltd.), 3-ethyl-3- (2-ethylhexyloxymethyl) oxetan (trade name OXT-212 manufactured by Toa Synthetic Co., Ltd.), 1,4-bis { [(3-Ethyl-3-oxetanyl) methoxy] methyl} benzene (trade name OXT-121 manufactured by Toa Synthetic Co., Ltd.), bis (3-ethyl-3-oxetanylmethyl) ether (trade name OXT-manufactured by Toa Synthetic Co., Ltd.) 221) and the like. Further, a phenol novolac type oxetane compound and the like can also be mentioned.

The oxetane compound can be used in combination with or alone with the epoxy compound, but since it has lower reactivity than the epoxy compound, care must be taken such as raising the curing temperature.

Next, examples of those used as a curing agent include polyfunctional phenol compounds, polycarboxylic acids and their acid anhydrides, aliphatic or aromatic primary or secondary amines, polyamide resins, and polymercapto compounds. Among these, polyfunctional phenol compounds, polycarboxylic acids and their acid anhydrides are preferably used from the viewpoint of workability and insulating properties.

As the polyfunctional phenol compound, a known and commonly used compound can be used as long as it is a compound having two or more phenolic hydroxyl groups in one molecule. Specific examples thereof include phenol novolac resin, cresol novolak resin, bisphenol A, allylated bisphenol A, bisphenol F, bisphenol A novolak resin, vinylphenol copolymer resin, and the like. In particular, phenol novolac resin is reactive. It is preferable because it has a high effect of increasing heat resistance. Such a polyfunctional phenolic compound also undergoes an addition reaction with the epoxy compound and / or the oxetane compound in the presence of a suitable curing catalyst.

The polycarboxylic acid and its acid anhydride are compounds having two or more carboxyl groups in one molecule and their acid anhydrides, for example, a copolymer of (meth) acrylic acid, a copolymer of maleic anhydride, and the like. Examples thereof include a condensate of a dibasic acid. Examples of commercially available products include John Krill (product group name) manufactured by Johnson Polymer Co., Ltd., SMA resin (product group name) manufactured by Arco Chemical Co., Ltd., and polyazelaic acid anhydride manufactured by Shin Nihon Rika Co., Ltd.

As the curing catalyst, an epoxy compound and / or an oxetane compound, a compound that serves as a curing catalyst for the reaction of a polyfunctional phenol compound and / or a polycarboxylic acid and its acid anhydride, or a polymerization catalyst when no curing agent is used. Examples of the compound, for example, a tertiary amine, a tertiary amine salt, a quaternary onium salt, a tertiary phosphine, a crown ether complex, a phosphonium ilide, and the like can be arbitrarily selected from these compounds. Can be used alone or in combination of two or more.

Among these, imidazoles having a trade name of 2E4MZ, C11Z, C17Z, 2PZ, etc., an AZINE compound of imidazole having a trade name of 2MZ-A, 2E4MZ-A, etc., and a trade name of 2MZ-OK, 2PZ-OK are preferable. Isocyanurate of imidazole such as, imidazole hydroxymethyl compound such as trade name 2PHZ, 2P4MHZ (all the trade names are manufactured by Shikoku Kasei Kogyo Co., Ltd.), dicyandiamide and its derivative, melamine and its derivative, diaminomaleonitrile and its Derivatives, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, bis (hexamethylene) triamine, trietanoamine diaminodiphenylmethane, amines such as organic acid dihydrazide, 1,8-diazabicyclo [5,4,0] undecene-7 ( Product name DBU, manufactured by San Apro Co., Ltd., 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane (trade name ATU, manufactured by Ajinomoto Co., Ltd.) ), Or an organic phosphine compound such as triphenylphosphine, tricyclohexylphosphine, tributylphosphine, methyldiphenylphosphine and the like.

The blending amount of these curing catalysts is usually sufficient in a quantitative ratio, and for example, 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the total of the epoxy compound and / or the oxetane compound is suitable.

(B-2) The photocurable resin may be an electrically insulating resin that is cured by irradiation with active energy rays, but a compound having one or more ethylenically unsaturated bonds in one molecule has heat resistance. It has excellent electrical insulation and can be preferably used. In this case, it is preferable to further use a photopolymerization initiator.
As the compound having one or more ethylenically unsaturated bonds in this one molecule, known and commonly used photopolymerizable oligomers, photopolymerizable vinyl monomers and the like are used.

Examples of the photopolymerizable oligomer include unsaturated polyester-based oligomers and (meth) acrylate-based oligomers. Examples of the (meth) acrylate-based oligomer include epoxy (meth) acrylates such as phenol novolac epoxy (meth) acrylate, cresol novolac epoxy (meth) acrylate, and bisphenol type epoxy (meth) acrylate, urethane (meth) acrylate, and epoxy urethane (meth). ) Acrylate, polyester (meth) acrylate, polyether (meth) acrylate, polybutadiene-modified (meth) acrylate and the like. In addition, in this specification, (meth) acrylate is a generic term for acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

Examples of the photopolymerizable vinyl monomer include known and commonly used styrene derivatives such as styrene, chlorostyrene and α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate or vinyl benzoate; vinyl isobutyl ether and vinyl. Vinyl ethers such as -n-butyl ether, vinyl-t-butyl ether, vinyl-n-amyl ether, vinyl isoamyl ether, vinyl-n-octadecyl ether, vinyl cyclohexyl ether, ethylene glycol monobutyl vinyl ether, triethylene glycol monomethyl vinyl ether; acrylamide , Methacrylicamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylate, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide and other (meth) acrylamides; triallyl isocyanurate, diallyl phthalate. , Allyl compounds such as diallyl isophthalate; 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tetrahydrofurfreel (meth) acrylate, isobolonyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate. (Meta) acrylic acid esters such as: hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxyalkyl (meth) acrylates such as pentaerythritol tri (meth) acrylate; methoxyethyl (meth) acrylate, ethoxy Alkoxyalkylene glycol mono (meth) acrylates such as ethyl (meth) acrylate; ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di. Alkylene polyol poly (meth) acrylates such as (meth) acrylates, trimethylolpropantri (meth) acrylates, pentaerythritol tetra (meth) acrylates, dipentaerythritol hexa (meth) acrylates; diethylene glycol di (meth) acrylates, triethylenes. Glycoldi (meth) acrylate, polyethylene glycol 200 di (meth) acrylate, ethoxylated trimethylolpropantriacrylate, propoxylated trimethylolpropanthry (meth) Polyoxyalkylene glycol poly (meth) acrylates such as acrylates; poly (meth) acrylates such as neopentyl glycol ester di (meth) acrylates; tris [(meth) acryloxyethyl] isocyanurates such as isocyanurate. Examples thereof include rate type poly (meth) acrylates. These can be used alone or in combination of two or more, depending on the characteristics of the coating film.

Examples of the photopolymerization initiator include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and benzyl methyl ketone, and alkyl ethers thereof. Acetphenone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, diethoxyacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1- Acetphenones such as dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one; methylanthoraquinone, 2-ethylantholaquinone , 2-Terrary butyl antholaquinone, 1-chloroanthoraquinone, 2-amylanthoraquinone and other anthoraquinones; thioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2 -Thioxanthones such as methylthioxanthone and 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethylketal and benzyldimethylketal; benzophenone, benzophenones such as 4,4-bismethylaminobenzophenone and the like. Be done. These can be used alone or in admixture of two or more, and further, tertiary amines such as trietanolamine and methyldietanolamine; 2-dimethylaminoethylbenzoic acid, ethyl 4-dimethylaminobenzoate and the like. It can be used in combination with a photoinitiator aid such as a benzoic acid derivative of.

When an alkali-developed photocurable resin composition is used as the (B) curable resin, a carboxyl group is added to the compound having an ethylenically unsaturated bond as a component of the (B-2) photocurable resin. In addition to the above-mentioned compound having an ethylenically unsaturated bond, a carboxyl group-containing resin having no ethylenically unsaturated bond can be used.

The high withstand voltage heat dissipation insulating resin composition of the present invention is preferably a coating type containing (C) an organic solvent. (C) The organic solvent is also used for adjusting the composition and adjusting the viscosity. As the organic solvent, any known organic solvent can be used, for example, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve. , Methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether and other glycol ethers; ethyl acetate, butyl acetate , Butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, esters such as propylene carbonate; aliphatic hydrocarbons such as octane and decane; Organic solvents such as petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha can be used. These organic solvents can be used alone or in combination of two or more.

The amount of the organic solvent (C) to be blended is preferably 3 to 10 parts by mass with respect to 100 parts by mass of the (A) high thermal conductive particles. (C) When the blending amount of the organic solvent is within this range, the generation of voids can be satisfactorily suppressed when the solvent is dried.

The high withstand voltage heat-dissipating insulating resin composition of the present invention can be added with a wetting / dispersing agent, if necessary, in order to facilitate high filling. Examples of such a wetting / dispersant include compounds having polar groups such as carboxyl groups, hydroxyl groups and acid esters, polymer compounds, acid-containing compounds such as phosphoric acid esters, copolymers containing acid groups and hydroxyl groups. Containing polycarboxylic acid ester, polysiloxane, long-chain polyaminoamide and acid ester salt and the like can be used.

Commercially available wetting and dispersants that can be particularly preferably used are Disperbyk®-101, -103, -110, -111, -160, -171, -174, -190,-. 300, Bykuman®, BYK-P105, -P104, -P104S, -240 (all manufactured by Big Chemie Japan), EFKA-Polymer 150, EFKA-44, -63, -64, -65, Examples thereof include -66, -71, -764, -766, and N (all manufactured by Fuka).

The high withstand voltage heat dissipation insulating resin composition of the present invention is further known and commonly used as phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black and the like, if necessary. Colorants, hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol, phenothiazine and other known and commonly used thermal polymerization inhibitors, finely divided silica, organic bentonite, montmorillonite and other known and commonly used thickeners, silica, barium sulfate, talc , Clay, hydrotalocyan and other known and customary extender pigments, silicon-based, fluorine-based and polymer-based defoaming agents and / or leveling agents and other known and customary additives can be blended. In the high withstand voltage heat-dissipating insulating resin composition of the present invention, it is preferable to use a silicon-based defoaming agent and a non-silicone-based defoaming agent in combination because bubbles (microbubbles) are removed by application.

It is preferable that the high withstand voltage heat-dissipating insulating resin composition of the present invention is adjusted to a viscosity suitable for the coating method with (C) an organic solvent, and coated on the substrate by a method such as a screen printing method.

When (B-1) a thermosetting resin is contained as the (B) curable resin of the high withstand voltage heat dissipation insulating resin composition, it is heat-cured by heating to a temperature of about 140 ° C. to 180 ° C. after application. Therefore, a cured coating film can be obtained.

When (B-2) a photocurable resin is contained as the (B) curable resin of the high withstand voltage insulating curable resin composition, after coating, ultraviolet rays are irradiated with a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like. And a cured coating can be obtained.

Further, as the (B) curable resin of the high withstand voltage insulating curable resin composition, an alkali-development type photocuring which is a mixture of (B-1) thermosetting resin and (B-2) photocurable resin. When the sex resin composition is contained, after coating, the pattern is exposed with ultraviolet rays such as a high-pressure mercury lamp, a metal halide lamp, and a xenon lamp, developed, and heated to a temperature of about 140 ° C. to 180 ° C. for thermosetting. A patterned cured coating can be obtained.

The present invention will be specifically described with reference to Examples and Comparative Examples of the present invention, but it goes without saying that the present invention is not limited to the following examples. In the following, "parts" and "%" mean "parts by mass" and "% by mass" unless otherwise specified.

(Synthesis of photopolymerizable oligomer (B-2))
900 g of diethylene glycol dimethyl ether and t-butylperoxy2-ethylhexanoate (perbutyl manufactured by Nippon Oil & Fat Co., Ltd.) in a 2-liter separable flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen introduction tube. O) 21.4 g was charged, and after heating to 90 ° C., 309.9 g of methacrylic acid, 116.4 g of methyl methacrylate, and lactone-modified 2-hydroxyethyl methacrylate represented by the general formula (I) (Dycel Chemical Industry Co., Ltd.) ) Praxel FM1) 109.8 g was added dropwise to diethylene glycol dimethyl ether together with 21.4 g of bis (4-t-butylcyclohexyl) peroxydicarbonate (Perloyl TCP manufactured by Nippon Yushi Co., Ltd.) over 3 hours, and further 6 hours. By aging, a carboxyl group-containing copolymer resin solution was obtained. The reaction was carried out in a nitrogen atmosphere.
Next, 363.9 g of 3,4-epoxycyclohexylmethyl acrylate (Cyclomer A200 manufactured by Daicel Chemical Co., Ltd.), 3.6 g of dimethylbenzylamine, and 1.80 g of hydroquinone monomethyl ether were added to the above carboxyl group-containing copolymer resin solution. , The temperature was raised to 100 ° C., and the epoxy was subjected to a ring-opening addition reaction by stirring. After 16 hours, a solution containing 53.8% (nonvolatile content) of a carboxyl group-containing copolymer resin having a solid acid value of 108.9 mgKOH / g and a weight average molecular weight of 25,000 (styrene equivalent) was obtained.

(Examples 1 to 5 and Comparative Examples 1 to 5)
The compounding components of Examples 1 to 5 and Comparative Examples 1 to 5 shown in Table 1 below were kneaded with a three-roll mill to obtain a curable resin composition.

＊１：電気化学工業（株）製 比表面積０．４ｍ^２／ｇの球状酸化アルミニウム
＊２：電気化学工業（株）製 比表面積０．４〜０．５ｍ^２／ｇの球状酸化アルミニウム
＊３：電気化学工業（株）製 比表面積０．５〜０．６ｍ^２／ｇの球状酸化アルミニウム
＊４：Ａｄｍａｔｅｃｈｓ社製 比表面積１．０〜１．８ｍ^２／ｇの球状酸化アルミニウム
＊５：Ａｄｍａｔｅｃｈｓ社製 比表面積６．５〜９．０ｍ^２／ｇの球状酸化アルミニウム
＊６：電気化学工業（株）製 比表面積１０〜１２ｍ^２／ｇの球状酸化アルミニウム
＊７：電気化学工業（株）製 比表面積８〜１０ｍ^２／ｇの球状酸化アルミニウム
＊８：電気化学工業（株）製 比表面積６〜８ｍ^２／ｇの球状酸化アルミニウム
＊９：ＥＶＯＮＩＫ社製 比表面積５５〜７５ｍ^２／ｇの超微粒子酸化アルミニウム
＊１０：信越化学工業（株）製シリコン系消泡剤
＊１１：ビック・ケミー・ジャパン（株）製非シリコン系消泡剤
＊１２：ビック・ケミー・ジャパン（株）製湿潤剤
＊１３：２，４−ジアミノ−６−［２’−メチルイミダゾリル−（１’）］−エチル−ｓ−トリアジン
＊１４：ＢＡＳＦ社製の光重合開始剤
＊１５：トリメチロールプロパントリアクリレート
＊１６：ＤＩＣ（株）製フェノールノボラック型エポキシ樹脂
＊１７：三菱ケミカル（株）製ビスフェノールＡ型エポキシ樹脂
なお、＊１〜＊９に記載の、各酸化アルミニウム粉末の比表面積は、ＢＥＴ法により測定したメーカー値である。

* 1: Denki Kagaku Kogyo Co., Ltd. specific surface area of 0.4 m ² / g of the spherical aluminum oxide * 2: manufactured by Denki Kagaku Kogyo Co., Ltd. specific surface area 0.4~0.5m ² / g of the spherical aluminum oxide * 3 : Spherical aluminum oxide with a specific surface area of 0.5 to 0.6 m ² / g manufactured by Denki Kagaku Kogyo Co., Ltd. * 4: Spherical aluminum oxide with a specific surface area of 1.0 to 1.8 m ² / g manufactured by Admatechs * 5: Admatechs Spherical aluminum oxide with a specific surface area of 6.5 to 9.0 m ² / g * 6: manufactured by Electrochemical Industry Co., Ltd. Spherical aluminum oxide with a specific surface area of 10 to 12 m ² / g * 7: manufactured by Electrochemical Industry Co., Ltd. specific surface area 8~10m ² / g of the spherical aluminum oxide * 8: Denki Kagaku Kogyo Co., Ltd. specific surface area 6-8 m ² / g of the spherical aluminum oxide * 9: ultra EVONIK Inc. specific surface area 55~75m ² / g Fine particle aluminum oxide * 10: Silicon-based defoaming agent manufactured by Shin-Etsu Chemical Industry Co., Ltd. * 11: Non-silicon-based defoaming agent manufactured by BIC Chemie Japan Co., Ltd. * 12: Wetting agent manufactured by BIC Chemie Japan Co., Ltd. * 13: 2,4-Diamino-6- [2'-methylimidazolyl- (1')] -ethyl-s-triazine * 14: Photopolymerization initiator manufactured by BASF * 15: Trimethylol propantriacrylate * 16 : DIC Co., Ltd. phenol novolac type epoxy resin * 17: Mitsubishi Chemical Co., Ltd. bisphenol A type epoxy resin The specific surface area of each aluminum oxide powder described in * 1 to * 9 was measured by the BET method. It is a manufacturer value.

The obtained curable resin composition was evaluated by the following evaluation method. The evaluation results are shown in Table 2.

(Thixotropy evaluation)
The curable resin composition was measured for viscosities at 5 rpm and 50 rpm at 25 ° C. using a cone plate type viscometer TV-30 manufactured by Toki Sangyo Co., Ltd., and the thixotropy of the ratio of the viscosity values of the two rotation speeds. (TI value) was calculated. If the thixo ratio is less than 1, it is called a dilatancy fluid, if it is greater than 1, it is called a thixotropic fluid, and if it is 1, it is called a Newtonian fluid. The property is poor and there is a problem with printability.

(Evaluation of leveling property on the coating film surface)
The curable resin composition was screen-printed, left at room temperature for 5 minutes, and dried in a hot air circulation type drying oven at 80 ° C. for 20 minutes. The smoothness of the coating film surface was observed and evaluated. The evaluation criteria are as follows.
〇: It was good.
X: The trace of the screen mesh was clearly left.

(Evaluation of bubbles in the coating film)
The presence or absence of microbubbles and voids was observed with a scanning electron microscope (SEM) on the cross section of the cured coating film prepared by evaluating the leveling property of the coating film surface. The evaluation criteria are as follows.
〇: There were no microbubbles or voids.
Δ: There were microbubbles or voids.
X: There were many microbubbles and voids.

(Solvent resistance evaluation)
The thermosetting resin compositions of Examples 1 to 4 and Comparative Examples 1 to 5 were pattern-printed on a circuit-formed FR-4 substrate by screen printing so that the dry coating film was about 30 μm, and the temperature was 150 ° C. Was cured for 60 minutes.
Further, the thermosetting and photocurable resin composition of Example 5 was pattern-printed on the circuit-formed FR-4 substrate so that the dry coating film was about 30 μm by screen printing, and 350 nm with a metal halide lamp. ^{After irradiating with an integrated light amount of 2} J / cm 2 at the same wavelength, the mixture was thermoset at 150 ° C. for 60 minutes. The obtained substrate was immersed in propylene glycol monomethyl ether acetate for 30 minutes, dried, and then peel-tested with a cellophane adhesive tape to evaluate peeling and discoloration of the coating film. The evaluation criteria are as follows.
◯: There was no peeling or discoloration.
X: There was peeling or discoloration.

(Heat resistance evaluation)
The thermosetting resin compositions of Examples 1 to 4 and Comparative Examples 1 to 5 and the thermosetting and photocurable resin compositions of Example 5 were used and cured in the same manner as in solvent resistance. A rosin-based flux is applied to the obtained substrate, allowed to flow in a solder bath at 260 ° C. for 10 seconds, washed and dried with propylene glycol monomethyl ether acetate, and then peel-tested with a cellophane adhesive tape to prevent the coating film from peeling off. evaluated. The evaluation criteria are as follows.
◯: There was no peeling.
X: There was peeling.

(Pencil hardness evaluation)
The thermosetting resin compositions of Examples 1 to 4 and Comparative Examples 1 to 5 and the thermosetting and photocurable resin compositions of Example 5 were used and cured in the same manner as in solvent resistance. The core of a pencil from B to 9H was sharpened on the obtained substrate so that the tip was flat, and the pencil was pressed at an angle of about 45 ° to record the hardness of the pencil at which the coating film did not peel off.

(Adhesion (adhesion to the grid) evaluation)
The thermosetting resin compositions of Examples 1 to 4 and Comparative Examples 1 to 5 were screen-printed on the FR-4 substrate on which the circuit was formed so that the dry coating film was about 30 μm, and the temperature was 150 ° C. It was cured for 60 minutes.
Further, the thermosetting and photocurable resin composition of Example 5 was pattern-printed on the circuit-formed FR-4 substrate so that the dry coating film was about 30 μm by screen printing, and 350 nm with a metal halide lamp. ^{After irradiating with an integrated light amount of 2} J / cm 2 at the same wavelength, the mixture was thermoset at 150 ° C. for 60 minutes.
The obtained substrate is made according to JIS K5400, 100 1 mm grids (10 x 10) are made on the film of each sample, and a transparent adhesive tape (manufactured by Nichiban Co., Ltd., width: 18 mm) is completely applied on the grids. After adhering, the tape was immediately pulled apart while keeping one end of the tape at a right angle to the glass substrate, and it was examined whether or not peeling occurred on the grid. The evaluation criteria are as follows.
◯: No peeling occurred on the grid.
X: Peeling occurred on the grid.

(Withstanding voltage measurement and evaluation)
The thermosetting resin compositions of Examples 1 to 4 and Comparative Examples 1 to 5 were printed on a copper-clad laminate by screen printing so that the dry coating film had a thickness of about 40 μm, and cured at 150 ° C. for 60 minutes.
Further, the photocurable and thermosetting resin composition of Example 5 was printed on a copper-clad laminate by screen printing so that the dry coating film was about 40 μm, and a metal halide lamp was used to print 2 J / cm at a wavelength of 350 nm. ^{After irradiating the integrated light amount of 2,} the test substrate was prepared by thermosetting at 150 ° C. for 60 minutes.
Using an AC / DC withstand voltage tester TOS5101 manufactured by Kikusui Electronics Co., Ltd., an electrode having a diameter of 10 mm was used in AC mode, and a value that did not cause dielectric breakdown was read and measured for 60 seconds. The measurement was performed with n = 3, and the average value was calculated. The evaluation criteria are as follows.
◯: The withstand voltage was 3 kV / 100 μm or more.
X: The withstand voltage was less than 3 kV / 100 μm.

(Measurement of thermal conductivity)
The thermosetting resin compositions of Examples 1 to 4 and Comparative Examples 1 to 5 were printed on rolled copper foil by screen printing so that the dry coating film had a thickness of about 50 μm, and cured at 150 ° C. for 60 minutes.
Further, the photocurable and thermosetting resin composition of Example 5 was printed on a rolled copper foil by screen printing so that the dry coating film was about 50 μm, and a metal halide lamp was used to print ^{2 J / cm 2 at a wavelength of 350 nm.} After irradiating the integrated light amount of the above, it was heat-cured at 150 ° C. for 60 minutes.
Then, the film-like cured product obtained by peeling the rolled copper foil was measured for thermal conductivity using QTM500 manufactured by Kyoto Denshi Kogyo Co., Ltd., and the average value of n = 3 was obtained.

比較例の評価結果は以下の通りである。
＊＊１および＊＊３：
比較例１および３については、最密充填できておらず、空隙があるため熱伝導率が若干低く、耐電圧が悪い結果となった。
＊＊２、＊＊４および＊＊５：
比較例２、４および５については、レベリングが悪く、塗膜表面にピンホールが発生した。塗膜中も消泡性が悪いため熱伝導率が低く、耐電圧特性もない、もしくは低いとの結果となった。

The evaluation results of the comparative example are as follows.
** 1 and ** 3:
In Comparative Examples 1 and 3, the close-packing was not possible, the thermal conductivity was slightly low due to the presence of voids, and the withstand voltage was poor.
** 2, ** 4 and ** 5:
In Comparative Examples 2, 4 and 5, the leveling was poor and pinholes were generated on the coating film surface. Since the defoaming property is poor even in the coating film, the thermal conductivity is low, and the withstand voltage characteristic is also poor or low.

As is clear from the results shown in Table 2, according to the present invention, regardless of whether the resin composition is thermosetting or photocurable, the resin composition has high thermal conductivity, good heat dissipation, and bubbles (micro). Since no valve) is generated, it is possible to prevent deterioration of the withstand voltage characteristics, and it is possible to provide a high withstand voltage heat dissipation insulating resin composition that does not require machining such as pressure molding or vacuum pressing.

Claims (8)

A high withstand voltage heat dissipation insulating resin composition containing (A) high thermal conductive particles and (B) curable resin.
The volume occupancy of the (A) high thermal conductive particles is 60% by volume or more with respect to the total solid content of the high withstand voltage heat dissipation insulating resin composition.
The ratio of the (A) high thermal conductive particles to the high thermal conductive particles having a specific surface area of 0.2 to 0.6 m ² / g measured by the (A-1) BET method and the (A-2) BET method. Contains high thermal conductive particles with a surface area of 6.0-12.5 m ^{2 / g,}
With respect to the total weight of the (A) high thermal conductive particles, the high thermal conductive particles having a specific surface area of 6.0 to 12.5 m ² / g measured by the (A-2) BET method were 5 to 16% by weight. A high withstand voltage heat dissipation insulating resin composition characterized by being present. The high withstand voltage heat dissipation insulating resin composition according to claim 1, further comprising (C) an organic solvent. The high withstand voltage heat dissipation insulating resin composition according to claim 1, which is a coating type. The high withstand voltage heat dissipation insulating resin composition according to claim 1, wherein the high thermal conductive particles (A) are aluminum oxide particles. The ratio of the (A) high thermal conductive particles to the high thermal conductive particles having a specific surface area of 0.2 to 0.6 m ² / g measured by the (A-1) BET method and the (A-2) BET method. The high withstand voltage heat dissipation insulating resin composition according to claim 1, which comprises only high thermal conductive particles having a surface area of 6.0 to 12.5 m ^{2 / g.} The high withstand voltage according to claim 1, wherein the (B) curable resin contains at least one of (B-1) a thermosetting resin and (B-2) a photocurable resin. Thermosetting resin composition. A cured product obtained by curing the high withstand voltage heat-dissipating insulating resin composition according to any one of claims 1 to 6. An electronic component having the cured product according to claim 7.