JP2019167425A - Thermosetting resin composition, dry film, cured product, and electronic component - Google Patents

Abstract

To provide a thermosetting resin composition or the like that makes it possible to obtain a cured product that suppresses sedimentation and aggregation of silica and has excellent crack resistance or the like at a low curing temperature.SOLUTION: The present invention provides a thermosetting resin composition or the like that contains (A) an epoxy resin, (B) curing agents, and (C) silica, wherein the (B) curing agents includes at least three selected from a compound having a phenolic hydroxyl group, a compound having an active ester group, a compound having a cyanate ester group, and a compound having a maleimide group. The (C) silica is a mixture of silica with an average particle size of 0.1-6 μm and silica with an average particle size of 0.01-0.5 μm. A peak difference in particle size distribution measurement between the silica with an average particle size of 0.1-6 μm and the silica with an average particle size of 0.01-0.5 μm is 0.05 μm or more.SELECTED DRAWING: None

Description

  The present invention relates to a thermosetting resin composition, a dry film, a cured product, and an electronic component.

  In recent years, attention has been paid to a multilayer printed wiring board manufactured by a build-up method in which a resin insulating layer and a conductor layer are alternately stacked on a conductor layer of an inner circuit board. For example, an epoxy resin composition is applied to an inner circuit board on which a circuit has been formed, heat-cured, then an opening is formed by laser processing, and a roughened surface having an uneven shape is formed on the surface of the resin insulating layer by a desmear liquid, A multilayer printed wiring board in which a conductor layer is formed by plating has been proposed. There has also been proposed a multilayer printed wiring board in which a dry film of an epoxy resin composition is laminated on a circuit-formed inner layer circuit board, heat-cured, and then a conductor layer is formed in the same manner as described above.

  As a composition used for the resin insulation layer of such a multilayer printed wiring board, for example, Patent Document 1 proposes a resin composition containing an epoxy resin, a cyanate ester resin, an active ester curing agent, and a curing accelerator. . In the Example of this patent document 1, it is described that the compounding quantity of a silica is about 60 mass%, and the thermosetting temperature is about 190 degreeC.

JP 2010-285594 A

  According to the prior art related to the proposal of Patent Document 1, the CTE (linear thermal expansion coefficient) of the cured product can be reduced by blending a large amount of silica. However, in a resin composition containing a large amount of silica, when a dry film is produced, if the resin composition is diluted so as to be easily coated on the film, silica contained in the resin composition is likely to settle. For this reason, if it takes time to apply, the silica settles and aggregates, and cracks are likely to occur starting from them. Further, the aggregated silica particles easily fall off during desmearing after the laser processing of the resin insulating layer, and as a result, the surface of the cured product becomes rough, so that it is difficult to reduce the surface of the cured product. It is only necessary to be able to apply the resin composition immediately after preparing the resin composition. However, in practice, it is used on a scale of 500 kg or more, and since it usually takes time to prepare and apply, There was a need for stabilization.

  In addition, when the curing temperature of the epoxy resin composition increases as in the prior art related to the proposal of Patent Document 1, the substrate is burnt, that is, a black oxide film is formed on the copper surface and discolors. It has been. However, when the temperature is low, it is difficult to sufficiently heat cure the epoxy resin composition, and there are problems such as reduced crack resistance of the cured product and increased surface roughness.

  Accordingly, an object of the present invention is to provide a thermosetting resin composition capable of obtaining a cured product that is excellent in crack resistance and the like at a low curing temperature, and in which sedimentation and aggregation of silica are suppressed, and a resin layer obtained from the composition It is providing the dry film which has this, the hardened | cured material of this composition or the resin layer of this dry film, and the electronic component which has this hardened | cured material.

  As a result of intensive studies in view of the above, the present inventors have used two kinds of silicas having different average particle sizes from the specific three kinds of curing agents, and the difference between the peaks in the particle size distribution measurement of the two kinds of silicas. The inventors have found that the above-mentioned problems can be solved by setting the specific value or more, and have completed the present invention.

  That is, the thermosetting resin composition of the present invention is a resin composition containing (A) an epoxy resin, (B) a curing agent, and (C) silica, and as the (B) curing agent, It includes at least any three of a compound having a phenolic hydroxyl group, a compound having an active ester group, a compound having a cyanate ester group, and a compound having a maleimide group, and the silica (C) has an average particle diameter of 0. It is a mixture of silica having 1 to 6 μm and silica having an average particle diameter of 0.01 to 0.5 μm, and silica having an average particle diameter of 0.1 to 6 μm and the average particle diameter of 0.01 to The difference between the peaks in the particle size distribution measurement of 0.5 μm silica is 0.05 μm or more.

  In the thermosetting resin composition of the present invention, the (C) silica is a mixture of silica having an average particle diameter of 0.1 to 3 μm and silica having an average particle diameter of 0.01 to 0.3 μm. And it is preferable that the difference between the peaks in the particle size distribution measurement of silica having an average particle size of 0.1 to 3 μm and silica having an average particle size of 0.01 to 0.3 μm is 0.05 μm or more.

  It is preferable that the thermosetting resin composition of this invention contains the said (C) silica 50 mass% or more with respect to the solid content whole quantity of a composition.

  The dry film of the present invention is characterized in that it has a resin layer obtained by applying the thermosetting resin composition to the film and drying it.

  The cured product of the present invention is obtained by curing the thermosetting resin composition or the resin layer of the dry film.

  The electronic component of the present invention is characterized by having the cured product.

  According to the present invention, there is provided a thermosetting resin composition capable of obtaining a cured product having suppressed cracking and aggregation of silica and having excellent crack resistance at a low curing temperature, and a resin layer obtained from the composition. It is possible to provide a dry film having a cured product, a cured product of the resin layer of the composition or the dry film, and an electronic component having the cured product.

  The thermosetting resin composition of the present invention is a resin composition containing (A) an epoxy resin, (B) a curing agent, and (C) silica, and as the (B) curing agent, phenolic It contains at least any three of a compound having a hydroxyl group, a compound having an active ester group, a compound having a cyanate ester group, and a compound having a maleimide group, and the silica (C) has an average particle size of 0.1 to 0.1. It is a mixture of 6 μm silica and silica having an average particle diameter of 0.01 to 0.5 μm, and silica having an average particle diameter of 0.1 to 6 μm and the average particle diameter of 0.01 to 0.00. The difference between the peaks in the particle size distribution measurement of 5 μm silica is 0.05 μm or more.

  According to the thermosetting resin composition of the present invention, since sedimentation and aggregation of silica are suppressed, even if it takes a long time to apply, the quality is excellent. That is, even if it takes time to prepare the thermosetting resin composition and apply it to the film, a dry film having the same quality as that applied immediately after the preparation can be obtained.

  In addition, since the silica drop-off during desmear due to the aggregation of silica is suppressed, the surface of the cured product can be made rough. In the case of an interlayer insulating layer, if the surface roughness is large, it becomes difficult to form a fine pattern electrode on the surface by plating during the build-up substrate formation, but the thermosetting resin composition of the present invention is a cured product. Since the surface can be made rough, it can be suitably used for forming an interlayer insulating layer.

  In addition, by suppressing the sedimentation and aggregation of the silica, it is possible to obtain an effect that the silica can be prevented from falling off from the wall surface of the cured film during desmearing after laser processing.

  The problem of sedimentation and aggregation of silica is particularly noticeable when the silica content is high, but according to the thermosetting resin composition of the present invention, when the silica content is high, for example, the solid content of the composition Even if it is 50 mass% or more with respect to the total amount, precipitation and aggregation of silica can be suppressed.

  Moreover, according to the thermosetting resin composition of the present invention, since the thermosetting temperature can be lowered, problems caused by the high temperature treatment so far, for example, substrate baking, that is, black oxide film on the surface of the copper foil It is also useful for preventing discoloration due to formation. Further, a cured product having excellent crack resistance and low surface roughness can be obtained.

  Hereinafter, the components contained in the thermosetting resin composition of the present invention will be described in detail.

[(A) Epoxy resin]
The thermosetting resin composition of the present invention contains (A) an epoxy resin. (A) The epoxy resin is a resin having an epoxy group, and any conventionally known one can be used. Examples thereof include a bifunctional epoxy resin having two epoxy groups in the molecule, and a polyfunctional epoxy resin having many epoxy groups in the molecule. A hydrogenated bifunctional epoxy resin may be used. Further, (A) the epoxy resin may be any of a solid epoxy resin, a semi-solid epoxy resin, and a liquid epoxy resin. In this specification, a solid epoxy resin refers to an epoxy resin that is solid at 40 ° C., and a semi-solid epoxy resin refers to an epoxy resin that is solid at 20 ° C. and is liquid at 40 ° C. Means an epoxy resin that is liquid at 20 ° C. Judgment of liquid state shall be made in accordance with the second “Liquid Confirmation Method” of the Ministerial Ordinance on Dangerous Goods Testing and Properties (Ministry of Local Government Ordinance No. 1 of 1989). For example, the method described in paragraphs 23 to 25 of JP-A-2016-079384 is performed. Among epoxy resins, it is preferable to include a semi-solid epoxy resin, and storage stability is improved when a dry film is formed. Moreover, when a semi-solid epoxy resin is included as an epoxy resin, it is more effective in suppressing sedimentation and aggregation than when a liquid epoxy resin is included.

As semi-solid epoxy resin, DIC Corporation Epicron 860, Epicron 900-IM, Epicron EXA-4816, Epicron EXA-4822, Asahi Ciba Araldite AER280, Toto Kasei Epoto YD-134, Mitsubishi Chemical Corporation jER834, jER872, bisphenol A type epoxy resin such as ELA-134 manufactured by Sumitomo Chemical Co., Ltd .; naphthalene type epoxy resin such as Epicron HP-4032 manufactured by DIC; phenol novolac type epoxy resin such as Epicron N-740 manufactured by DIC .
The semisolid epoxy resin preferably contains at least one selected from the group consisting of bisphenol A type epoxy resins, naphthalene type epoxy resins and phenol novolac type epoxy resins. By including a semisolid epoxy resin, the glass transition temperature (Tg) of the cured product is high, the CTE is low, and the crack resistance is excellent. By including a semi-solid epoxy resin, the storage stability of the dry film is excellent, and cracking and peeling can be prevented.

  As the solid epoxy resin, HP-4700 (naphthalene type epoxy resin) manufactured by DIC, EXA4700 (tetrafunctional naphthalene type epoxy resin) manufactured by DIC, NC-7000 (polyfunctional solid epoxy resin containing naphthalene skeleton) manufactured by Nippon Kayaku Co., Ltd. Naphthalene-type epoxy resins such as EPPN-502H (trisphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd. Epoxidized products (trisphenol-type epoxy resins) of condensation products of phenols and aromatic aldehydes having a phenolic hydroxyl group; Dicyclopentadiene aralkyl epoxy resin such as Epiklon HP-7200H (dicyclopentadiene skeleton-containing polyfunctional solid epoxy resin) manufactured by Nippon Kayaku Co., Ltd .; biphenyl aralkyl such as NC-3000H (biphenyl skeleton-containing polyfunctional solid epoxy resin) manufactured by Nippon Kayaku Co., Ltd. Type Epoxy Resin; biphenyl / phenol novolac type epoxy resin such as NC-3000L manufactured by Nippon Kayaku; novolak type epoxy resin such as Epicron N660 and Epicron N690 manufactured by DIC, EOCN-104S manufactured by Nippon Kayaku; YX- manufactured by Mitsubishi Chemical Biphenyl type epoxy resin such as 4000; Phosphorus-containing epoxy resin such as TX0712 manufactured by Nippon Steel & Sumikin Chemical Co .; Tris (2,3-epoxypropyl) isocyanurate such as TEPIC manufactured by Nissan Chemical Industries, Ltd. By including the solid epoxy resin, the glass transition temperature of the cured product is increased and the heat resistance is excellent.

  Liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, glycidylamine type epoxy resin, aminophenol type epoxy resin And alicyclic epoxy resins. By including a liquid epoxy resin, the flexibility of the dry film is excellent.

  (A) An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. (A) It is preferable that the compounding quantity of an epoxy resin is 5-20 mass parts with respect to 100 mass parts of solid content of a composition.

  The thermosetting resin composition of the present invention may contain a thermosetting resin other than the epoxy resin (A) as long as the effects of the present invention are not impaired. For example, an isocyanate compound, a blocked isocyanate compound, an amino resin , Known thermosetting resins such as benzoxazine resin, carbodiimide resin, cyclocarbonate compound, polyfunctional oxetane compound and episulfide resin can be used.

[(B) Curing agent]
The thermosetting resin composition of the present invention is (B) at least one of a compound having a phenolic hydroxyl group, a compound having an active ester group, a compound having a cyanate ester group, and a compound having a maleimide group as the curing agent. Includes 3 types. In the present invention, the thermosetting temperature can be lowered by including such three kinds of curing agents. Of the curing agents, any one is preferably a compound having an active ester group.

  Examples of the compound having a phenolic hydroxyl group include phenol novolac resin, alkylphenol volac resin, bisphenol A novolac resin, dicyclopentadiene type phenol resin, Xylok type phenol resin, terpene modified phenol resin, cresol / naphthol resin, polyvinylphenols, Conventionally known resins such as a phenol / naphthol resin, an α-naphthol skeleton-containing phenol resin, a triazine skeleton-containing cresol novolak resin, a biphenyl aralkyl type phenol resin, and a zylock type phenol novolak resin can be used. The compound which has a phenolic hydroxyl group may be used individually by 1 type, and may be used in combination of 2 or more type. As the compound having a phenolic hydroxyl group, a compound having a phenolic hydroxyl group not containing a triazine ring is preferably used from the viewpoint of storage stability.

  Among the compounds having a phenolic hydroxyl group, the hydroxyl group equivalent is 100 g / eq. The above is preferable. Hydroxyl equivalent weight is 100 g / eq. Examples of the compound having a phenolic hydroxyl group include a dicyclopentadiene skeleton phenol novolak resin (GDP series, manufactured by Gunei Chemical Co., Ltd.), a zylock type phenol novolak resin (MEH-7800, manufactured by Meiwa Kasei Co., Ltd.), and a biphenyl aralkyl type. Novolac resin (MEH-7851, manufactured by Meiwa Kasei Co., Ltd.), naphthol aralkyl type curing agent (SN series, manufactured by Nippon Steel & Sumikin Co., Ltd.), triazine skeleton-containing cresol novolac resin (LA-3018-50P, manufactured by DIC), triazine skeleton-containing phenol A novolac resin (LA-705N, manufactured by DIC) and the like can be mentioned.

  The compound having a cyanate ester group is preferably a compound having two or more cyanate ester groups (—OCN) in one molecule. As the compound having a cyanate ester group, any conventionally known compounds can be used. Examples of the compound having a cyanate ester group include a phenol novolak type cyanate ester resin, an alkylphenol novolak type cyanate ester resin, a dicyclopentadiene type cyanate ester resin, a bisphenol A type cyanate ester resin, a bisphenol F type cyanate ester resin, and a bisphenol S type. Examples include cyanate ester resins. Further, it may be a prepolymer partially triazine. The compound which has a cyanate ester group may be used individually by 1 type, and may be used in combination of 2 or more type. As the compound having a cyanate ester group, those having a novolak structure are preferable from the viewpoints of reactivity and heat resistance.

  Commercially available compounds having a cyanate ester group include a phenol novolak type polyfunctional cyanate ester resin (manufactured by Lonza Japan Co., Ltd., PT30S), and a prepolymer in which a part or all of bisphenol A dicyanate is triazine and becomes a trimer. (Lonza Japan, BA230S75), dicyclopentadiene structure-containing cyanate ester resin (Lonza Japan, DT-4000, DT-7000) and the like.

  The compound having an active ester group is preferably a compound having two or more active ester groups in one molecule. A compound having an active ester group can generally be obtained by a condensation reaction between a carboxylic acid compound and a hydroxy compound. Especially, the compound which has an active ester group obtained using a phenol compound or a naphthol compound as a hydroxy compound is preferable. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol , Dicyclopentadienyl diphenol, phenol novolac and the like. Further, the compound having an active ester group may be naphthalenediol alkyl / benzoic acid type. The compound which has an active ester group may be used individually by 1 type, and may be used in combination of 2 or more type. As the compound having an active ester group, those having any of α-naphthol, β-naphthol and dicyclopentadiene skeleton are preferable.

  Examples of commercially available compounds having an active ester group include cyclopentadiene-type diphenol compounds such as HPC8000-65T (manufactured by DIC), HPC8100-65T (manufactured by DIC), and HPC8150-65T (manufactured by DIC). Can be mentioned.

  The compound having a maleimide group is a compound having a maleimide skeleton, and any conventionally known compound can be used. The compound having a maleimide group preferably has two or more maleimide skeletons, such as N, N′-1,3-phenylene dimaleimide, N, N′-1,4-phenylene dimaleimide, N, N′-4. , 4-diphenylmethane bismaleimide, 1,2-bis (maleimide) ethane, 1,6-bismaleimide hexane, 1,6-bismaleimide- (2,2,4-trimethyl) hexane, 2,2′-bis- [4- (4-Maleimidophenoxy) phenyl] propane, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethane bismaleimide, 4-methyl-1,3-phenylenebismaleimide, bis ( 3-ethyl-5-methyl-4-maleimidophenyl) methane, bisphenol A diphenyl ether bismaleimide, polyphenylmethane Imides, and more preferably at least any one kind of diamine condensates with these oligomers and maleimide skeleton. The said oligomer is an oligomer obtained by condensing the compound which has a maleimide group which is a monomer among the compounds which have the above-mentioned maleimide group. As the compound having a maleimide group, one type may be used alone, or two or more types may be used in combination. As the compound having a maleimide group, those having a novolak structure are preferred.

  Commercially available compounds having a maleimide group include BMI-1000 (4,4′-diphenylmethane bismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-2300 (phenylmethane bismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI- 3000 (m-phenylene bismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-5100 (3,3′-dimethyl-5,5′-dimethyl-4,4′-diphenylmethane bismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI -7000 (4-methyl-1,3-phenylene bismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-TMH ((1,6-bismaleimide-2,2,4-trimethyl) hexane, manufactured by Daiwa Kasei Kogyo Co., Ltd. ) And the like.

  (B) It is preferable that the compounding quantity of a hardening | curing agent is 1-20 mass parts with respect to 100 mass parts of solid content of a composition.

  The thermosetting resin composition of the present invention may contain a curing agent other than the above-mentioned curing agents as long as the effects of the present invention are not impaired. Examples of other curing agents include polycarboxylic acids and acid anhydrides thereof, and alicyclic olefin polymers.

[(C) Silica]
The thermosetting resin composition of the present invention contains (C) silica as an inorganic filler component. Silica suppresses curing shrinkage of the cured product of the thermosetting composition, lowers CTE, and improves properties such as adhesion and hardness. The silica (C) contained in the thermosetting resin composition of the present invention has an average particle diameter of 0.1 to 6 μm (hereinafter, also referred to as “large diameter silica”) and an average particle diameter of 0.01 to 6 μm. Silica having a mixture of 0.5 μm silica (hereinafter also referred to as “small-diameter silica”), the average particle size of 0.1-6 μm, and the average particle size of 0.01-0.5 μm The difference between the peaks in the particle size distribution measurement is 0.05 μm or more. Although the detailed mechanism is not clear, the combination of such large diameter silica and small diameter silica makes it difficult for the large diameter silica to settle. As a result, the dispersion stability is excellent and aggregation is suppressed. Further, it is possible to prevent roughening due to the falling off of silica during desmearing. Two or more types of large-diameter silica and small-diameter silica may be contained. Silica is not particularly limited, and examples thereof include fused silica, spherical silica, amorphous silica, and crystalline silica. Silica is preferably spherical particles. In addition, in this specification, the average particle diameter (median diameter, D50) of silica is an average particle diameter including not only the particle diameter of primary particles but also the particle diameter of secondary particles (aggregates). The average particle diameter and the peak value can be obtained by a laser diffraction particle diameter distribution measuring apparatus. An example of a measuring apparatus using the laser diffraction method is Nanotrac wave manufactured by Nikkiso Co., Ltd. In addition, when 3 or more types of silica are included, the average particle size is 0.01 to 0.5 μm, and the minimum particle size silica is 0.01 to 0.5 μm, and other silicas have an average particle size of 0.1 to 6 μm. Any difference between the peaks in the particle size distribution measurement with the smallest silica in the range of 0.05 μm or more corresponds to the large-diameter silica.

  The average particle diameter of the large-diameter silica is preferably 0.1 to 3 μm, and more preferably 0.2 to 1 μm. The smaller the average particle size, the better the surface roughness of the cured product after desmearing, and the suppression of silica precipitation and aggregation.

  The average particle size of the small-diameter silica is preferably 0.01 to 0.3 μm, more preferably 0.01 to 0.2 μm, and still more preferably 0.01 to 0.1 μm. The smaller the average particle size, the better the surface roughness of the cured product after desmearing, and the suppression of silica precipitation and aggregation.

  The difference between the peaks in the particle size distribution measurement of the large silica and the small silica is preferably 0.05 μm or more. In addition, the maximum value of the difference between the peaks in the particle size distribution measurement of silica is, for example, 5 μm.

  The large diameter silica and the small diameter silica may be surface-treated. As the surface treatment, a surface treatment that does not introduce an organic group such as a surface treatment with a coupling agent or an alumina treatment may be performed. The surface treatment method of silica is not particularly limited, and a known and commonly used method may be used, and the surface of silica is treated with a surface treatment agent having a curable reactive group, for example, a coupling agent having a curable reactive group as an organic group. What is necessary is just to process. Aggregation can be further prevented by surface treatment.

  The surface treatment of silica is preferably a surface treatment with a coupling agent. As the coupling agent, coupling agents such as silane, titanate, aluminate and zircoaluminate can be used. Of these, silane coupling agents are preferred. Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminomethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-amino. Propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxy (Cyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned, and these can be used alone or in combination. These silane coupling agents are preferably immobilized in advance on the surface of silica by adsorption or reaction. Here, the processing amount of the coupling agent with respect to 100 parts by mass of silica is, for example, 0.5 to 10 parts by mass.

  As the curable reactive group, a thermosetting reactive group is preferable. Examples of thermosetting reactive groups include hydroxyl groups, carboxyl groups, isocyanate groups, amino groups, imino groups, epoxy groups, oxetanyl groups, mercapto groups, methoxymethyl groups, methoxyethyl groups, ethoxymethyl groups, ethoxyethyl groups, oxazoline groups, etc. Is mentioned. Among these, at least one of an amino group and an epoxy group is preferable. In addition, the surface-treated silica may have a photocurable reactive group in addition to the thermosetting reactive group.

  In addition, the surface-treated silica should just be contained in the thermosetting resin composition in the surface-treated state, and mix | blends a silica and a surface treating agent separately in a thermosetting resin composition, and is a composition. Although silica may be surface-treated in the product, it is preferable to blend silica that has been surface-treated in advance. By blending silica that has been surface-treated in advance, it is possible to prevent a decrease in crack resistance or the like due to the surface treatment agent that has not been consumed by the surface treatment that may remain when blended separately. When the surface treatment is performed in advance, it is preferable to blend a pre-dispersed liquid in which silica is pre-dispersed in a solvent or a curable component. Whether the pre-dispersed surface-treated silica is pre-dispersed in a solvent and the pre-dispersed liquid is blended in the composition. More preferably, after the surface-untreated silica is sufficiently surface-dispersed in the solvent, the pre-dispersed liquid is blended into the composition.

  Silica may be blended with an epoxy resin or the like in a powder or solid state, or may be blended with an epoxy resin or the like after being mixed with a solvent or a dispersant to form a slurry. By making the slurry, the number of coarse particles is small, and it is possible to prevent the silica from falling off the processing wall surface during the desmear treatment after laser processing.

  The compounding amount of the large-diameter silica is preferably 5 to 80% by mass based on the total solid content of the composition.

  It is preferable that the compounding quantity of the said small diameter silica is 5-15 mass% on the solid content whole quantity basis of a composition.

  The blending mass ratio of the large diameter silica and the small diameter silica is preferably 20: 1 to 5: 1.

  Further, as described above, the problem of sedimentation of the inorganic filler is particularly remarkable when the content of the inorganic filler is high. In the present invention, when the amount of silica is large, for example, the total amount of the large-diameter silica and the small-diameter silica is 50% by mass or more, further 55% by mass or more, or even 70% with respect to the total solid content of the composition. A particularly excellent effect can be obtained in the case of mass% or more. As an upper limit, it is 90 mass% or less with respect to the solid content whole quantity of a composition, for example.

  The thermosetting resin composition of the present invention may contain a filler other than the large-diameter silica and the small-diameter silica as long as the effects of the present invention are not impaired. As fillers other than silica, barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica and other silica, talc, clay, Neuburg silica particles, boehmite, magnesium carbonate, calcium carbonate, titanium oxide , Body pigments such as aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, calcium zirconate, metal powders such as copper, tin, zinc, nickel, silver, palladium, aluminum, iron, cobalt, gold, platinum, etc. Inorganic fillers and organic fillers such as tetrafluoroethylene (PTFE).

(Thermoplastic resin (polymer resin))
The thermosetting resin composition of the present invention can further contain a thermoplastic resin in order to improve the mechanical strength of the resulting cured film. The thermoplastic resin is preferably soluble in a solvent. When it is soluble in a solvent, the flexibility is improved when it is made into a dry film, and the generation of cracks and powder falling can be suppressed. As the thermoplastic resin, use is made of thermoplastic polyhydroxy polyether resin, phenoxy resin that is a condensate of epichlorohydrin and various bifunctional phenolic compounds, or hydroxyl group of hydroxy ether part present in the skeleton of various acid anhydrides and acid chlorides. And esterified phenoxy resin, polyvinyl acetal resin, polyamide resin, polyamideimide resin, block copolymer and the like. A thermoplastic resin can be used individually by 1 type or in combination of 2 or more types. A phenoxy resin is preferable from the viewpoint of heat resistance. From the viewpoint of reducing the roughness of the surface of the cured product after desmearing, a polyvinyl acetal resin is preferable.

  As the polyvinyl acetal resin, for example, it can be obtained by acetalizing a polyvinyl alcohol resin with an aldehyde. The aldehyde is not particularly limited, and for example, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, amylaldehyde, hexylaldehyde, heptylaldehyde, 2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, benzaldehyde, 2-methylbenzaldehyde, 3- Examples include methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpropionaldehyde, and the like, butyraldehyde is preferable.

  Specific examples of the phenoxy resin include FX280 and FX293 manufactured by Toto Kasei Co., Ltd., YX8100, YX6954, YL6954, and YL6974 manufactured by Mitsubishi Chemical Corporation. As specific examples of the polyvinyl acetal resin, the SEREC KS series manufactured by Sekisui Chemical Co., Ltd., as the polyamide resin, the KS5000 series manufactured by Hitachi Chemical Co., Ltd., the BP series manufactured by Nippon Kayaku Co., Ltd., and the polyamideimide resin KS9000 series manufactured by Hitachi Chemical Co., Ltd.

  It is preferable that the compounding quantity of a thermoplastic resin is 0.5-5 mass parts with respect to 100 mass parts of composition solid content whole quantity.

(Rubbery particles)
The thermosetting resin composition of the present invention can contain rubber-like particles as necessary. Examples of such rubber-like particles include polybutadiene rubber, polyisopropylene rubber, urethane-modified polybutadiene rubber, epoxy-modified polybutadiene rubber, acrylonitrile-modified polybutadiene rubber, carboxyl group-modified polybutadiene rubber, acrylonitrile butadiene rubber modified with a carboxyl group or a hydroxyl group, and These crosslinked rubber particles, core-shell type rubber particles, and the like can be mentioned, and one kind can be used alone or two or more kinds can be used in combination. These rubber-like particles are added to improve the flexibility of the resulting cured film, improve crack resistance, enable surface roughening treatment with an oxidizing agent, and improve the adhesion strength with copper foil, etc. Is done.

  The average particle diameter of the rubber-like particles is preferably in the range of 0.005 to 1 μm, and more preferably in the range of 0.2 to 1 μm. The average particle size of the rubber-like particles in the present invention can be determined by a laser diffraction type particle size distribution measuring device. For example, rubber-like particles are uniformly dispersed in an appropriate organic solvent by ultrasonic waves, etc., and a particle size distribution of the rubber-like particles is created on a mass basis using Nanotrac wave manufactured by Nikkiso Co., Ltd. It can be measured by doing.

  The compounding amount of the rubber-like particles is preferably 0.5 to 10% by mass, and more preferably 1 to 5% by mass with respect to the total solid content of the composition. In the case of 0.5% by mass or more, crack resistance is obtained, and the adhesion strength with a conductor pattern or the like can be improved. When the content is 10% by mass or less, the coefficient of thermal expansion (CTE) decreases, the glass transition temperature (Tg) increases, and the curing characteristics are improved.

(Curing accelerator)
The thermosetting resin composition of the present invention can contain a curing accelerator. The curing accelerator is for accelerating the thermosetting reaction, and is used for further improving properties such as adhesion, chemical resistance, and heat resistance. Specific examples of such curing accelerators include imidazole and derivatives thereof; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, Polyamines such as melamine and polybasic hydrazides; organic acid salts and / or epoxy adducts thereof; amine complexes of boron trifluoride; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4- Triazine derivatives such as diamino-6-xylyl-S-triazine; trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa (N-methyl) Amines such as lamin, 2,4,6-tris (dimethylaminophenol), tetramethylguanidine, m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac; tributylphosphine, tri Organic phosphines such as phenylphosphine and tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide and hexadecyltributylphosphonium chloride; benzyltrimethylammonium chloride and phenyltributylammonium chloride Quaternary ammonium salts such as polybasic acid anhydrides; diphenyliodonium tetrafluoroboroate, triphenyl Photocationic polymerization catalyst such as sulfonium hexafluoroantimonate and 2,4,6-triphenylthiopyrylium hexafluorophosphate; styrene-maleic anhydride resin; equimolar reaction product of phenyl isocyanate and dimethylamine, tolylene diisocyanate, Conventionally known curing accelerators such as an equimolar reaction product of an organic polyisocyanate such as isophorone diisocyanate and dimethylamine, and a metal catalyst can be used. Among the curing accelerators, phosphonium salts are preferred because BHAST resistance is obtained. From the viewpoint of compatibility between reactivity and storage stability, an imidazole or imidazole derivative having a DSC reaction peak temperature of 100 ° C. or higher is preferable. In addition, the peak temperature of the reaction by DSC means a peak temperature generated when 10 mg of the thermosetting resin composition of the present invention is placed in an aluminum pan and heated from room temperature to 300 ° C. at 10 ° C./min.

  A hardening accelerator can be used individually by 1 type or in mixture of 2 or more types. The use of a curing accelerator is not essential, but when it is desired to accelerate curing, it can be preferably used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the epoxy resin. In the case of a metal catalyst, 10 to 550 ppm is preferable in terms of metal with respect to 100 parts by mass of the compound having a cyanate ester group, and 25 to 200 ppm is more preferable.

(Organic solvent)
The organic solvent is not particularly limited, and examples thereof include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. it can. More specifically, ketones such as methyl ethyl ketone, cyclohexanone, methyl butyl ketone, and methyl isobutyl ketone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methylcarbitol Glycol ethers such as butyl carbitol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; Ethyl acetate, butyl acetate, isobutyl acetate, ethylene glycol monoethyl ether acetate, di Esters such as propylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate; ethanol, propanol, 2-methoxypropanol, n-butanol, isobutyl alcohol, isopentyl alcohol, ethylene glycol, Alcohols such as propylene glycol; Aliphatic hydrocarbons such as octane and decane; Petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha; N, N-dimethylformamide (DMF), tetrachloroethylene , Turpentine and the like. In addition, Maruzen Petrochemical Co., Ltd. Swazol 1000, Swazol 1500, Standard Petroleum Osaka Sales Co., Ltd. Solvesso 100, Solvesso 150, Sankyo Chemical Co., Ltd. Solvent # 100, Solvent # 150, Shell Chemicals Japan Co., Ltd. Shell Sol A100, Shell Sol A150 Organic solvents such as Ipsol No. 100 and Ipsol No. 150 manufactured by Idemitsu Kosan Co., Ltd. may be used. An organic solvent may be used individually by 1 type and can be used as a mixture of 2 or more types.

  In the case of forming a dry film, the residual solvent amount in the resin layer is preferably 0.5 to 7.0% by mass. When the residual solvent is 7.0% by mass or less, bumping at the time of thermosetting is suppressed, and the flatness of the surface becomes better. Moreover, it can suppress that melt viscosity falls too much and resin flows, and flatness becomes favorable. When the residual solvent is 0.5% by mass or more, the fluidity during lamination is good, and the flatness and embedding are better.

(Other ingredients)
The thermosetting resin composition of the present invention may further comprise a conventionally known colorant such as phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, if necessary. Conventionally known thickeners such as asbestos, olben, benton, fine silica, etc., defoamers and / or leveling agents such as silicones, fluorines and polymers, thiazoles, triazoles, silane coupling agents, etc. Adhesiveness imparting agents, flame retardants, titanate-based and aluminum-based conventionally known additives can be used.

  The thermosetting resin composition of the present invention may be used as a dry film or as a liquid. When used as a liquid, it may be one-component or two-component or more, but it is preferably two-component or more from the viewpoint of storage stability.

[Dry film]
The dry film of the present invention can be produced by applying the thermosetting resin composition of the present invention on a carrier film and drying to form a resin layer as a dry coating film. A protective film can be laminated on the resin layer as necessary.

  A carrier film has a role which supports the resin layer of a dry film, and is a film by which a thermosetting resin composition is apply | coated when forming this resin layer. As the carrier film, for example, a polyester film such as polyethylene terephthalate or polyethylene naphthalate, a polyimide film, a polyamideimide film, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a film made of a thermoplastic resin such as a polystyrene film, and Surface-treated paper or the like can be used. Among these, a polyester film can be preferably used from the viewpoints of heat resistance, mechanical strength, handleability, and the like. The thickness of the carrier film is not particularly limited, but is appropriately selected depending on the application in the range of about 10 to 150 μm. The surface on which the resin layer of the carrier film is provided may be subjected to release treatment. Moreover, the surface which provides the resin layer of a carrier film may form sputter | spatter or ultra-thin copper foil.

  The protective film is provided on the surface opposite to the carrier film of the resin layer for the purpose of preventing dust and the like from adhering to the surface of the resin layer of the dry film and improving the handleability. As the protective film, for example, a film made of a thermoplastic resin exemplified for the carrier film, surface-treated paper, and the like can be used. Among these, a polyester film, a polyethylene film, and a polypropylene film are preferable. The thickness of the protective film is not particularly limited, but is appropriately selected depending on the intended use within a range of about 10 to 150 μm. The surface on which the resin layer of the protective film is provided may be subjected to a mold release treatment.

  As a method for producing a printed wiring board using the thermosetting resin composition of the present invention, a conventionally known method may be used. For example, in the case of a dry film having a three-layer structure in which a resin layer is sandwiched between a carrier film and a protective film, a printed wiring board can be produced by the following method. Either the carrier film or the protective film is peeled off from the dry film, heat laminated to the circuit board on which the circuit pattern is formed, and then thermally cured. The heat curing may be performed in an oven or by a hot plate press. When laminating or hot plate pressing the substrate on which the circuit is formed and the dry film of the present invention, the copper foil or the substrate on which the circuit is formed can be laminated simultaneously. A printed wiring board can be manufactured by forming a pattern or a via hole by laser irradiation or drilling at a position corresponding to a predetermined position on the substrate on which the circuit pattern is formed, and exposing the circuit wiring. At this time, if there is a component (smear) that cannot be completely removed on the circuit wiring in the pattern or via hole, desmear processing is performed. The remaining carrier film or protective film may be peeled off after lamination, after heat curing, after laser processing, or after desmear treatment. Note that the connection method of the interlayer circuit may be a connection using a copper pillar.

  The thermosetting resin composition of the present invention can be preferably used for the formation of a permanent protective film of a printed wiring board, and is preferably used for the formation of a solder resist layer, an interlayer insulating layer, and a cover lay of a flexible printed wiring board. it can. In particular, since it is excellent in reducing the roughness of the cured product surface, it can be particularly preferably used for forming an interlayer insulating layer. Moreover, the thermosetting resin composition of this invention can be preferably used for the use which forms hardened | cured material with much inorganic filler content. It can also be suitably used for permanent hole filling of printed wiring boards, for example, hole filling such as through holes and via holes. It can also be used as a sealing material for semiconductor chips. You may form a wiring board by bonding a wiring together using the dry film of this invention. The electronic component may be an application other than the printed wiring board, for example, a passive component such as an inductor.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples and comparative examples of the present invention. However, the present invention is not limited to the following examples. In the following description, “parts” and “%” are all based on mass unless otherwise specified.

<Preparation of thermosetting resin composition>
The solvents described in the examples and comparative examples in the following table were placed in a container, stirred while heating to 50 ° C., and then all except the filler components in the table were added. After confirming that each component was dissolved, the filler component was added and sufficiently stirred. Thereafter, a thermosetting resin composition was prepared by kneading with a three-roll mill. In addition, the numerical value in a table | surface shows a mass part. Moreover, solid content is shown except a solvent.

<Sedimentation after stirring and standing>
The adjusted thermosetting resin composition was put into a transparent glass screw tube and subjected to storage aging treatment for 24 hours in a constant temperature warehouse set at 30 ° C. The thermosetting resin composition was charged 50 mm from the bottom of the screw tube. Then, the thermosetting resin composition was taken out and visually observed from the side surface to confirm the sedimentation state. The evaluation criteria are as follows.
A: No settling is observed.
◯: A transparent supernatant of less than 1 mm was confirmed from the top of the composition.
(Triangle | delta): The transparent supernatant liquid of about 1 mm or more and less than 10 mm was confirmed from the upper part of the composition.
X: A transparent supernatant liquid of 10 mm or more was confirmed from the upper part of the composition. When the sediment was confirmed with a grindometer, agglomerated particles were confirmed.

<Peak temperature by DSC>
The thermosetting resin composition was packed in an aluminum pan, and the reaction peak temperature was confirmed with DSC-7000 (manufactured by Hitachi High-Tech Science Co., Ltd.). Measurement conditions were from room temperature to 300 ° C. at a temperature rising method of 10 ° C./min. The evaluation criteria are as follows. In addition, when the peak temperature by DSC is low, it is excellent in low-temperature curability. It also serves as an index for preventing substrate burning.
A: The peak temperature of the reaction is less than 185 ° C.
(Triangle | delta): The peak temperature of reaction is 185 degreeC or more and less than 195 degreeC.
X: The peak temperature of reaction is 195 degreeC or more.

<Production of dry film>
Adjust the amount of the solvent so that the viscosity of 0.5 to 20 dPa · s (rotary viscometer 5 rpm, 25 ° C.) of the thermosetting resin composition aged under the above conditions, respectively, using a bar coater, The resin layer was applied to a carrier film (PET film; Lumirror 38R75 manufactured by Toray Industries, Inc., 38 μm thick) so that the film thickness would be 40 μm after drying. Next, it is dried for 5 to 10 minutes at 70 to 120 ° C. (average 100 ° C.) so that the residual solvent of the resin layer is 0.5 to 2.5% by mass in a hot air circulation drying oven, and then on the carrier film. A resin layer was formed.

<Storage stability of DF>
The produced dry film was subjected to storage aging treatment for 24 hours in a constant temperature warehouse set at 23 ° C. Thereafter, in accordance with JISK5600-5-1 (ISO 1519), using a cylindrical mandrel bending tester manufactured by BYK-Gardner, the mandrel starts to crack and peel off from the carrier film of each example and comparative example. The hardness of the dry film was evaluated from the minimum diameter. The evaluation criteria are as follows.
A: The diameter is less than 2 mm and there is no cracking or peeling.
A: The diameter was less than 2 mm, and the resin was slightly cracked.
(Triangle | delta): The diameter of (phi) 2 mm-less than 5 mm, and the crack of the resin and the powder fall were confirmed.
X: Resin cracking and powder falling were confirmed at a diameter of 5 mm or more.

<CTE>
The produced dry film was laminated on a glossy surface of electrolytic copper foil (GTS-MP-18, manufactured by Furukawa Circuit Foil Co., Ltd.) using a vacuum laminator MVLP-500 (manufactured by Meiki Seisakusho Co., Ltd.). The conditions were a temperature of 80 to 110 ° C. and a pressure of 0.5 MPa. Then, after peeling a carrier film, material was hardened in the hot air circulation type drying furnace. The conditions were 100 ° C. × 30 minutes + 180 ° C. × 60 minutes. Subsequently, the obtained cured product was peeled off from the copper foil. Thereafter, a sample was cut out from the cured product into a measurement size (size of 3 mm × 10 mm), and measurement was performed using TMA6100 manufactured by Seiko Instruments Inc. In the TMA measurement, the sample was heated from room temperature at a heating rate of 10 ° C./min at a test load of 5 g and measured twice continuously. The average thermal expansion coefficient (CTE (α1)) from 30 ° C. to 100 ° C. in the second round was evaluated (unit: ppm).

<Roughness after desmear>
A double-sided printed wiring board having a copper thickness of 15 μm and a circuit formed thereon having a thickness of 0.4 mm was prepared, and pre-treatment was performed using CZ-8100 manufactured by MEC. Thereafter, the produced dry film was laminated on a circuit board using a two-chamber vacuum laminator CVP-600 (manufactured by Nichigo Morton). The conditions were laminating and pressing, respectively, at a temperature of 80 to 110 ° C. and a pressure of 0.5 MPa. Subsequently, the carrier film was peeled off, and then the material was cured in a hot air circulation type drying furnace. The conditions were 100 ° C. × 30 min + 180 ° C. × 60 min. About the obtained board | substrate, using the roughening liquid (Swelling dip securigans P (swelling), concentrate compact CP (oxidation), reduction solution securigant P (neutralization)) by Atotech Japan Co., Ltd. The treatment was performed in the order of swelling 60 ° C. × 5 minutes, oxidation 80 ° C. × 20 minutes, and neutralization 40 ° C. × 5 minutes. Then, each surface roughness Ra was measured about the printed wiring board by which the desmear process was carried out with laser microscope VK-8500 (the Keyence company make, measurement magnification 2000 times, Z-axis direction measurement pitch 10nm). The Ra value was an average value of 10 points in the entire measurement range. The evaluation criteria are as follows.
A: Ra is less than 150 nm.
◯: Ra is 150 nm or more and less than 250 nm.
X: Ra is 250 nm or more.

<Laser workability and state after desmear>
A copper-clad substrate with a copper thickness of 15 μm and a plate thickness of 0.4 mm was prepared, and pre-treatment was performed using MEC CZ-8100. Thereafter, the dry film having a thickness of 40 μm of the produced resin layer was bonded onto the copper-clad substrate using a two-chamber vacuum laminator CVP-600 (manufactured by Nichigo Morton). Then, it heated at 100 degreeC * 30min + 180 degreeC * 60min, the cured film was formed on the copper clad board | substrate, and the carrier film was peeled. Next, vias were formed on the cured film using a CO ₂ laser processing machine (manufactured by Hitachi Via Mechanics Co., Ltd.) so as to have a top diameter of 65 μm and a bottom diameter of 50 μm, and laser workability was evaluated according to the following. Next, using a roughening solution (Swelling Dip Securigans P (swelling), Concentrate Compact CP (oxidation), Reduction Solution Securigant P (neutralization)) manufactured by Atotech Japan, 60 ° C. swelling The treatment was performed in the order of × 5 minutes, oxidation 80 ° C. × 20 minutes, neutralization 40 ° C. × 5 minutes. With respect to the obtained substrate, the bottom size of the via was observed with a laser microscope, and the state of the via wall surface was observed with an SEM. The via formation conditions and evaluation criteria are as follows.
Aperture (mask diameter): 3.1 mm / pulse width: 20 μsec / output: 2 W / frequency: 5 kHz / burst mode ○: The difference from the target machining diameter is ± 2 μm or more and less than ± 5 μm in 3 shots. No via bottom smear.
Δ: The difference from the target processing diameter is ± 5 μm or more. After desmearing, the fillers were confirmed to agglomerate and fall off the wall surface.

<Crack resistance>
For the substrate after laser processing, the via bottom was cleaned by the method described in <Roughness after desmear>. Next, the electroless copper plating (Sulcup PEA, manufactured by Uemura Kogyo Co., Ltd.) and the electrolytic copper plating treatment are performed in this order, and the copper plating treatment is performed so that the via thickness is filled on the resin layer on which the laser via is formed. Was given. Next, curing was performed at 190 ° C. for 60 minutes in a hot-air circulating drying furnace to obtain a completely cured copper-plated test substrate. The obtained test substrate was subjected to thermal history with one cycle of −65 ° C. for 30 minutes and 150 ° C. for 30 minutes. After 2000 cycles, in order to observe the state of the via bottom and the wall surface with an optical microscope, the via center was cut and polished with a precision cutting machine, and the cross-sectional state was observed. The evaluation criteria are as follows. The number of observation vias was 100 holes.
A: No cracking occurred.
A: The rate of occurrence of cracks in the material from 1% to less than 5% starting from the via bottom.
◯: From the via bottom, the crack occurrence rate in the material is 5% or more and less than 10%.
(Triangle | delta): From the via | veer bottom, the crack generation rate inside a material is 10% or more and less than 20%.
×: Crack generation rate in the material inside is 20% or more starting from the via bottom.

* 1: jER828 manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent of 189 g / eq, liquid * 2: Epicron N-740 manufactured by DIC, phenol novolac type epoxy resin, epoxy equivalent of 182 g / eq, semi-solid * 3: NC-3000H manufactured by Nippon Kayaku Co., biphenyl novolak type epoxy compound, epoxy equivalent 290 g / eq
* 4: Lonza Japan Primaset PT-30, Novolak-type cyanate resin, cyanate equivalent 124 g / eq, solid * 5: DIC Corporation Epicron HPC-8000, active ester resin, active equivalent 223 g / eq, solid * 6: DIC LA-3018, ATN-containing cresol novolac resin, hydroxyl group equivalent 151 g / eq, solid * 7: Meiwa Kasei HF-1M, phenol novolac resin, hydroxyl group equivalent 104-108 g / eq
* 8: BMI-2300 manufactured by Daiwa Kasei Kogyo, phenylmethane bismaleimide, maleimide equivalent 187 g / eq, solid * 9: FX-293 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., phenoxy resin, weight average molecular weight 40,000 to 50,000, Tg 158 ℃
* 10: Sekisui Chemical Co., Ltd. KS-10 H30, polyvinyl acetal, KS-10 dissolved in cyclohexanone, solid content 30%
* 11: Shikoku Kasei Co., Ltd. 2PHZ, 2-phenyl-4,5-dihydroxymethylimidazole * 12: Tokyo Chemical Industry Co., Ltd. CO (II) cobalt (II) acetylacetonate, powder * 13: Admatex SO- C2, spherical silica, average particle size (D50) = 0.5 μm (same as the peak value in particle size distribution measurement)
* 14: Admatechs SO-C1, spherical silica, average particle size (D50) = 200 nm (the same as the peak value in the particle size distribution measurement)
* 15: Admatex YA050SV2, spherical silica treated with 1% by mass with vinylsilane KBM-1003, average particle size (D50) = 50 nm (same as the peak value in particle size distribution measurement)
* 16: Tatsumori MUF-1BV, spherical silica, average particle size (D50) = 3 μm (same as the peak value in particle size distribution measurement)
* 17: SO-C5 manufactured by Admatechs, spherical silica, average particle size (D50) = 1.5 μm (the same as the peak value in the particle size distribution measurement)
* 18: ASFP-20 manufactured by Denka Co., Alumina, average particle size (D50) = 0.3 μm (same as the peak value in particle size distribution measurement)
* 19: Shin-Etsu Silicone KBM-403, epoxy silane coupling agent * 20: methyl ethyl ketone

From the results shown in the above table, it can be seen that the thermosetting resin compositions of the examples can obtain a cured product in which sedimentation and aggregation of silica are suppressed and excellent in crack resistance and the like at a low curing temperature.

Claims (6)

A resin composition comprising (A) an epoxy resin, (B) a curing agent, and (C) silica,
The (B) curing agent includes at least any three of a compound having a phenolic hydroxyl group, a compound having an active ester group, a compound having a cyanate ester group, and a compound having a maleimide group,
The (C) silica is a mixture of silica having an average particle diameter of 0.1 to 6 μm and silica having an average particle diameter of 0.01 to 0.5 μm, and the average particle diameter is 0.1 to A thermosetting resin composition characterized in that a difference between peaks in a particle size distribution measurement of 6 μm silica and silica having an average particle size of 0.01 to 0.5 μm is 0.05 μm or more.   The (C) silica is a mixture of silica having an average particle diameter of 0.1 to 3 μm and silica having an average particle diameter of 0.01 to 0.3 μm, and the average particle diameter is 0.1 to 3 μm. 2. The thermosetting resin composition according to claim 1, wherein a difference between peaks in a particle size distribution measurement of 3 μm silica and silica having an average particle size of 0.01 to 0.3 μm is 0.05 μm or more. object.   The thermosetting resin composition according to claim 1, wherein the (C) silica is contained in an amount of 50% by mass or more based on the total solid content of the composition.   It has a resin layer obtained by apply | coating and drying the thermosetting resin composition as described in any one of Claims 1-3 to a film, The dry film characterized by the above-mentioned.   A cured product obtained by curing the thermosetting resin composition according to any one of claims 1 to 3 or the resin layer of the dry film according to claim 4. An electronic component comprising the cured product according to claim 5.