JPWO2020066601A1 - Curable resin composition, dry film, cured product, printed wiring board and electronic components - Google Patents

Abstract

While satisfying the performance required for solder resists such as high adhesion, high resolution, high insulation reliability (HAST resistance), and high crack resistance (TCT resistance), the package substrate was subjected to high-temperature and long-term thermal history. Provided is a curable resin composition or the like, which generates less outgas in the case, that is, can suppress weight loss, and has excellent resistance to high temperature standing. A curable resin composition containing (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photopolymerization initiator, and (D) an inorganic filler, wherein the Gardner color number of the (B) epoxy resin is 3 or less, and (B) epoxy resin contains (B-1) or less, an epoxy resin having a structure of the formula (I), and (B-2) a liquid trifunctional epoxy resin having an isocyanul ring. A curable resin composition or the like, which is characterized by the above.

Description

The present invention relates to curable resin compositions, dry films, cured products, printed wiring boards and electronic components.

In recent years, due to the rapid progress of semiconductor parts, electronic devices tend to be lighter, thinner, shorter, smaller, have higher performance, and have more functions. Following this tendency, miniaturization and multi-pinization of semiconductor packages have been put into practical use.
Specifically, instead of IC packages called QFP (quad flat pack package), SOP (small outline package), etc., BGA (ball grid array), CSP (chip scale package), etc. An IC package called is used. In recent years, FC-BGA (flip chip ball grid array) has also been put into practical use as an IC package with a higher density.
In a printed wiring board (also referred to as a package substrate) used for such an IC package, the SRO (Solder Rest Opening) pitch is narrow and formed close to each other, so that short circuits and crosstalk noise occur between the SROs. There is a high risk of crosstalk. Further, the solder resist formed between the SROs is thin and thin, so that cracks are likely to occur. Therefore, a permanent coating such as a solder resist used for a package substrate is required to have high reliability over a long period of time, specifically, high insulation reliability. In particular, as the density of package substrates increases in the future, the demand for reliability is expected to increase further.

Japanese Patent No. 5167113

However, regarding this reliability, the thermosetting resin composition described in Patent Document 1 described above has become insufficient in recent years.
In recent years, in wire bonding package substrates, the number of I / O has increased and the wire material has been changed from gold to copper for the purpose of reducing costs. Such specifications are increasing, and the generation of outgas in the solder resist at that time has become a problem. When outgas is generated in the solder resist, the capillary is contaminated, which leads to shortening of the life of the capillary and accompanying increase in production cost and deterioration of yield.

Therefore, an object of the present invention is to satisfy the performance required for a solder resist such as high adhesion, high resolution, high insulation reliability (HAST resistance), and high crack resistance (TCT resistance), and to provide a package substrate with a high temperature length. A curable resin composition having excellent resistance to high temperature standing, which generates less outgas when a heat history of time is applied, that is, can suppress weight loss, and a dry film having a resin layer obtained from the curable resin composition. It is an object of the present invention to provide a curable resin composition or a cured product of a resin layer of the dry film, a printed wiring board having the cured product, and an electronic component having the printed wiring board.

（Ｂ−２）イソシアヌル環を有する液状３官能エポキシ樹脂と、を含有することを特徴とするものである。As a result of diligent research and development, the present inventors have identified the epoxy resin as the epoxy resin having a high light transmittance of 3 or less Gardner colors and containing trisphenol methane and bisphenol A in the skeleton as the epoxy resin. By using the above epoxy resin in combination, it has been found that a cured product that generates less outgas can be obtained, and the present invention has been completed. That is, the curable resin composition of the present invention is a curable resin composition containing (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photopolymerization initiator, and (D) an inorganic filler. (B) The epoxy resin has a Gardner color number of 3 or less, and (B) the epoxy resin has a structure of the formula (I) of (B-1) or less.

(B-2) It is characterized by containing a liquid trifunctional epoxy resin having an isocyanul ring.

In the curable resin composition of the present invention, the content of the (D) inorganic filler is preferably 30 to 70% by mass, and the (C) photopolymerization initiator is preferably an oxime ester. Further, it is preferable that the liquid trifunctional epoxy resin having the (B-2) isocyanul ring is an epoxy resin having the structure of the following formula (II).

The dry film of the present invention is characterized by having a resin layer obtained by applying the curable resin composition to the film and drying it.
Further, the cured product of the present invention is characterized in that it is obtained by curing the resin layer of the curable resin composition or the dry film.
Further, the printed wiring board of the present invention is characterized by having the above-mentioned cured product.
Furthermore, the electronic component of the present invention is characterized by having the printed wiring board.

According to the present invention, the package substrate is subjected to a high temperature for a long time while satisfying the performance required for a solder resist such as high adhesion, high resolution, high insulation reliability (HAST resistance), and high crack resistance (TCT resistance). A curable resin composition having an excellent resistance to high temperature standing, which generates less outgas when the heat history is applied, that is, can suppress weight loss, a dry film having a resin layer obtained from the curable resin composition, and the like. A curable resin composition or a cured product of the resin layer of the dry film, a printed wiring board having the cured product, and an electronic component having the printed wiring board can be obtained.

The curable resin composition of the present invention is a curable resin composition containing (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photopolymerization initiator, and (D) an inorganic filler. (B) The number of Gardner colors of the epoxy resin is 3 or less, and (B) the epoxy resin has (B-1) an epoxy resin having the structure of the formula (I) and (B-2) an isocyanul ring. It is characterized by containing a liquid trifunctional epoxy resin.

As described above, the curable resin composition of the present invention has a high light transmittance with a Gardner color number of 3 or less and contains trisphenol methane and bisphenol A as the epoxy resin in the skeleton of the (B) epoxy resin (B). -1) An epoxy resin having the structure of the formula (I) and a liquid trifunctional epoxy resin having an isocyanul ring (B-2) are used in combination, whereby outgas is generated less and the weight is reduced. It has the characteristics of being able to suppress the problem and having excellent resistance to high temperature leaving.
Among the characteristics of the (B) epoxy resin of the curable resin composition of the present invention, the number of Gardner colors is as low as 3 or less, that is, the light transmittance is high, so that the deep portion of the coating film coated with the curable resin composition is applied. The light reaches up to. Therefore, the transmitted light can enhance the reactivity of the photoreactive functional group contained in the (A) carboxyl group-containing resin or the like even in the deep part, and the cured product can be sufficiently cured.
Further, the epoxy resin having the structure of the above formula (I) containing trisphenol methane and bisphenol A described in the characteristics of the (B) epoxy resin of the curable resin composition of the present invention in the skeleton is Since it is an aromatic polyfunctional epoxy having a high softening point, it is excellent in toughness and heat resistance, and (B-2) a liquid trifunctional epoxy resin having an isocyanul ring is excellent in reaction completion and cross-linking density improving effect. Therefore, since the curable resin composition of the present invention uses these epoxy resins (B-1) and (B-2) in combination, the reactivity of the epoxy can be enhanced.
As described above, in the present invention, by using the (B) epoxy resin having the above-mentioned characteristics, the reactivity of the (A) carboxyl group-containing resin can be enhanced even in the deep part, and the reactivity of the epoxy can be further improved. Can be enhanced. Therefore, decomposition can be suppressed even during high-temperature heat history, and thus the effective resin composition of the present invention has a feature that generation of outgas is small, that is, weight loss is suppressed, and resistance to high-temperature standing is excellent. ..

Hereinafter, each component of the curable resin composition of the present invention will be described. 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.

[(A) Carboxyl group-containing resin]
As the carboxyl group-containing resin, various conventionally known carboxyl group-containing resins having a carboxyl group in the molecule can be used. In particular, a carboxyl group-containing photosensitive resin having an ethylenically unsaturated double bond in the molecule is preferable from the viewpoint of photocurability and development resistance. The ethylenically unsaturated double bond is preferably derived from acrylic acid or methacrylic acid or a derivative thereof. When only a carboxyl group-containing resin having no ethylenically unsaturated double bond is used, in order to make the composition photocurable, a compound having a plurality of ethylenically unsaturated groups in the molecule described later, that is, light It is necessary to use a reactive monomer together.
Specific examples of the carboxyl group-containing resin include the following compounds (either oligomer or polymer).

(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, or isobutylene.

(2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates, carboxyl group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, polycarbonate-based polyols and polyether-based compounds. A carboxyl group-containing urethane resin obtained by a double addition reaction of a diol compound such as a polyol, a polyester-based polyol, a polyolefin-based polyol, an acrylic-based polyol, a bisphenol A-based alkylene oxide adduct diol, and a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(3) Diisocyanate and bifunctional epoxy resin such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenel type epoxy resin, biphenol type epoxy resin ( Meta) A carboxyl group-containing photosensitive urethane resin obtained by a double addition reaction of an acrylate or a modified partial acid anhydride thereof, a carboxyl group-containing dialcohol compound, and a diol compound.

(4) During the synthesis of the resin according to (2) or (3), a compound having one hydroxyl group and one or more (meth) acryloyl groups in a molecule such as hydroxyalkyl (meth) acrylate is added to the terminal (4). Meta) Acryloylated carboxyl group-containing photosensitive urethane resin.

(5) During the synthesis of the resin according to (2) or (3), one isocyanate group and one or more (meth) acryloyl groups are formed in the molecule, such as an isophorone diisocyanate and pentaerythritol triacrylate isomorphic reaction product. A carboxyl group-containing photosensitive urethane resin that is terminal (meth) acrylicized by adding the compound to be possessed.

(6) A carboxyl group-containing photosensitive resin obtained by reacting a bifunctional or higher polyfunctional (solid) epoxy resin with (meth) acrylic acid and adding a dibasic acid anhydride to a hydroxyl group existing in a side chain.

(7) Carboxyl obtained by reacting (meth) acrylic acid with a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl group of a bifunctional (solid) epoxy resin with epichlorohydrin, and adding dibasic anhydride to the generated hydroxyl group. Group-containing photosensitive resin.

(8) A dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid is reacted with a bifunctional oxetane resin, and the generated primary hydroxyl group is subjected to two bases such as phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. Carboxyl group-containing polyester resin to which acid anhydride is added.

(9) An epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol, and (meth). Reacting with an unsaturated group-containing monocarboxylic acid such as acrylic acid, maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipine with respect to the alcoholic hydroxyl group of the obtained reaction product. A carboxyl group-containing resin obtained by reacting a polybasic anhydride such as an acid.

(10) Reaction production obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide with an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting a substance with a polybasic acid anhydride.

(11) Obtained by reacting an unsaturated group-containing monocarboxylic acid with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate. A carboxyl group-containing photosensitive resin obtained by reacting a reaction product with a polybasic acid anhydride.

(12) A carboxyl group-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth) acryloyl groups in one molecule to the resins (1) to (11).
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.

The carboxyl group-containing resin (A) is not limited to those listed above, and one type may be used alone or a plurality of types may be mixed and used. Among them, the carboxyl group-containing resin synthesized by using a phenol compound such as the carboxyl group-containing resins (10) and (11) as a starting material is suitable for HAST test under high voltage, that is, B-HAST resistance and PCT resistance. Since it is excellent, it can be preferably used.

The acid value of the carboxyl group-containing resin (A) is preferably 20 to 200 mgKOH / g. When the acid value of the carboxyl group-containing resin (A) is 20 to 200 mgKOH / g, the pattern of the cured product can be easily formed. More preferably, it is 50 to 130 mgKOH / g.

The weight average molecular weight of the (A) carboxyl group-containing resin varies depending on the resin skeleton, but is generally preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. When the weight average molecular weight is 2,000 or more, the development resistance of the film in the exposed portion is improved, and the resolution is excellent. On the other hand, when the weight average molecular weight is 150,000 or less, the solubility of the unexposed portion is good, the resolution is excellent, and the storage stability may be improved. The weight average molecular weight can be measured by gel permeation chromatography.

The blending amount of the carboxyl group-containing resin (A) is, for example, 5 to 50% by mass, preferably 10 to 40% by mass, based on the total amount of the curable resin composition excluding the solvent. The coating film strength can be improved by setting the content to 5% by mass or more, preferably 10% by mass or more. Further, by setting it to 50% by mass or less, preferably 40% by mass or less, the viscosity becomes appropriate and the workability is improved.

[(B) Epoxy resin]
[(B-1) Epoxy resin having the structure of formula (I) containing trisphenol methane and bisphenol A in the skeleton]
The curable resin composition of the present invention contains an epoxy resin having the structure of the above formula (I) containing trisphenol methane and bisphenol A in the skeleton, which is, for example, Techmore (registered trademark) manufactured by Mitsui Chemicals, Inc. ) Available as VG3101L or NC-6300H manufactured by Nippon Kayaku Co., Ltd. Techmore VG3101L is a pale yellow solid having a softening point of 60 ° C. and a Gardner color number of 3 or less, and an epoxy equivalent of 210 g / eq. It has characteristics such as high heat resistance, low water absorption and low curing shrinkage at 1000 ppm or less of total chlorine.

[(B-2) Liquid trifunctional epoxy resin having an isocyanul ring]
The curable resin composition of the present invention contains a liquid trifunctional epoxy resin having an isocyanul ring, which can be obtained as, for example, TEPIC-VL and TEPIC-FL manufactured by Nissan Chemical Industries, Ltd., of which TEPIC- VL is preferable because of heat resistance and low curing shrinkage. TEPIC-VL is an epoxy resin having the structure of the following formula (II), is a colorless transparent liquid having Gardner color number 1 or less, has viscosity, and has an epoxy equal amount of 135 g / eq. It is small and has characteristics such as total chlorine of 200 ppm or less, high heat resistance, high light resistance, low water absorption and low curing shrinkage.

The curable resin composition of the present invention, together with the above-mentioned epoxy resins (B-1) and (B-2), satisfies the requirement of the present invention that "the number of Gardner colors of the epoxy resin is 3 or less" and Epoxy resins other than the epoxy resins (B-1) and (B-2) described above can be included as long as the effects peculiar to the present invention are not impaired. The epoxy resins other than the above-mentioned (B-1) and (B-2) epoxy resins are epoxidized vegetable oil; bisphenol A type epoxy resin; hydroquinone type epoxy resin; bisphenol type epoxy resin; thioether type epoxy resin; bromide epoxy. Resin; Novolak type epoxy resin; Biphenol Novolak type epoxy resin; Bisphenol F type epoxy resin; Hydrogenated bisphenol A type epoxy resin; Glycidylamine type epoxy resin; Hydantin type epoxy resin; Alicyclic epoxy resin; Trihydroxyphenylmethane type epoxy Resin; Bixylenel type or biphenol type epoxy resin or a mixture thereof; Bisphenol S type epoxy resin; Bisphenol A novolak type epoxy resin; Tetraphenylol ethane type epoxy resin; Heterocyclic epoxy resin; Diglycidyl phthalate resin; Tetraglycidylxi Lenoyl ethane resin; naphthalene group-containing epoxy resin; epoxy resin having a dicyclopentadiene skeleton; glycidyl methacrylate copolymerized epoxy resin; cyclohexyl maleimide and glycidyl methacrylate copolymerized epoxy resin; epoxy-modified polybutadiene rubber derivative; CTBN-modified Epoxy resin and the like can be mentioned, but the present invention is not limited to these.

The blending amount of the epoxy resin (B) is, for example, 10 to 100 parts by mass, preferably 10 to 80 parts by mass, and more preferably 20 to 60 parts by mass with respect to 100 parts by mass of the (A) carboxyl group-containing resin. When the blending amount of the epoxy resin (B) is 10 parts by mass or more, crack resistance and insulation reliability are further improved, and when it is 100 parts by mass or less, storage stability is improved.

Further, the ratio of the amount of the epoxy resin having the structure of the formula (I) containing (B-1) trisphenol methane and bisphenol A in the skeleton to the amount of the liquid trifunctional epoxy resin having (B-2) isocyanul ring. Is preferably 1: 6 to 6: 1 on a mass basis, and particularly preferably 1: 3 to 3: 1. The ratio of the amount of the epoxy resin having the structure of the formula (I) containing (B-1) trisphenol methane and bisphenol A to the amount of the liquid trifunctional epoxy resin having the (B-2) isocyanul ring is 1 : If it is 6 or more, the heat resistance is improved, and the (B-2) isocyanul ring in the amount of the epoxy resin having the structure of the formula (I) containing (B-1) trisphenol methane and bisphenol A in the skeleton is formed. When the ratio of the liquid trifunctional epoxy resin to the blending amount is 6: 1 or less, the developability and the laminateability are good. Further, the blending amount of the epoxy resin having the structure of the formula (I) containing (B-1) trisphenol methane and bisphenol A in 100 parts by mass of the (B) epoxy resin and the (B-2) isocyanul ring are added. The total amount of the liquid trifunctional epoxy resin to be contained is preferably 50 to 100 parts by mass, more preferably 80 to 100 parts by mass. The total amount of the epoxy resin having the structure of the formula (I) containing (B-1) trisphenol methane and bisphenol A in the skeleton and the amount of the liquid trifunctional epoxy resin having the (B-2) isocyanul ring is 50. When it is more than a mass part, heat resistance and outgas reduction effect can be obtained.

[(C) Photopolymerization Initiator]
As the photopolymerization initiator (C), any photopolymerization initiator known as a photopolymerization initiator or a photoradical generator can be used, and for example, bis- (2,6-dichlorobenzoyl) can be used. ) Phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2) , 6-Dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine Oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (Omnirad manufactured by IGM Resins) 819 ) Etc. bisacylphosphine oxides; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methyl Monoacylphosphine oxides such as benzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO manufactured by IGM Resins); 1- Hydroxy-cyclohexylphenyl ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1- {4- [4- ( 2-Hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one and other hydroxyacetophenones; benzoyl, Benzoyls such as benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers; benzophenone, p-methylbenzophenone, Michler's ketone, methyl benzofe Benzopenes such as non, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1 -Dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholino) Phenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl)] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N, N-dimethylamino Acetphenones such as acetophenone; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; anthraquinone, Anthracinones such as chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylantraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal. Ethyl benzoate esters such as ethyl-4-dimethylaminobenzoate, 2- (dimethylamino) ethyl benzoate, p-dimethylbenzoic acid ethyl ester; 1,2-octanedione, 1- [4- (phenylthio) −, 2 -(O-benzoyloxime)], etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime) and other oxime esters Bis (η5-2,4-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis [ Titanosenes such as 2,6-difluoro-3- (2- (1-pyr-1-yl) ethyl) phenyl] titanium; phenyldisulfide 2-nitrofluorene, butyloin, anisoine ethyl ether, azobisisobutyronitrile , Tetramethylthiuram disulfide and the like. As the photopolymerization initiator, one type may be used alone, or two or more types may be used in combination. Of these, monoacylphosphine oxides and oxime esters are preferable, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3. -Il]-, 1- (O-acetyloxime) is more preferable.

The blending amount of the (C) photopolymerization initiator is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the (A) carboxyl group-containing resin. When it is 0.5 parts by mass or more, the surface curability is good, and when it is 20 parts by mass or less, halation is less likely to occur and good resolution can be obtained.

[(D) Inorganic filler]
The curable resin composition of the present invention contains (D) an inorganic filler. The inorganic filler is not particularly limited, and known and commonly used fillers such as silica, crystalline silica, Neuburg silica soil, aluminum hydroxide, glass powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, and the like. Inorganic fillers such as aluminum hydroxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, mineral wool, aluminum silicate, calcium silicate, and zinc flower can be used. Of these, silica is preferable, and spherical silica is more preferable because it has a small surface area and stress is dispersed throughout, so that it is unlikely to be the starting point of cracks.

The inorganic filler may be subjected to a photoreactive surface treatment so as to have a vinyl group, a styryl group, a methacrylic group, an acrylic group or the like as the photocurable reactive group. In this case, the methacrylic group, the acrylic group or vinyl may be treated. Groups are particularly preferred. Further, as the thermosetting reactive group, a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, an imino group, an epoxy group, an oxetanyl group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group and an oxazoline group. The surface treatment may be thermally reactive so as to have the above, and in this case, an amino group and an epoxy group are particularly preferable. Furthermore, the (D) inorganic filler may have two or more curable reactive groups. As the inorganic filler (D), surface-treated silica is preferable. By including the surface-treated silica, the CTE can be lowered and the glass transition temperature can be raised.

(D) The introduction method when introducing the curable reactive group onto the surface of the inorganic filler is not particularly limited, and it may be introduced by using a known and commonly used method, and a surface treatment agent having a curable reactive group, for example, curing The surface of the inorganic filler may be treated with a coupling agent or the like having a sex reactive group.

As the surface treatment of the inorganic filler (D), a surface treatment with a coupling agent is preferable. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent and the like can be used. Of these, a silane coupling agent is preferable.

As the silane coupling agent, a silane coupling agent capable of introducing a curing reactive group into the (D) inorganic filler is preferable. Examples of the silane coupling agent into which a thermosetting reactive group can be introduced include a silane coupling agent having an epoxy group, a silane coupling agent having an amino group, a silane coupling agent having a mercapto group, and a silane coupling agent having an isocyanate group. Agents are mentioned, and among them, a silane coupling agent having an epoxy group is more preferable. Examples of the silane coupling agent into which a photocurable reactive group can be introduced include a silane coupling agent having a vinyl group, a silane coupling agent having a styryl group, a silane coupling agent having a methacryl group, and a silane coupling agent having an acrylic group. Agents are preferred, with silane coupling agents having a methacryl group being more preferred.

When the (D) inorganic filler is surface-treated, it is sufficient that the inorganic filler is blended in the curable resin composition of the present invention in the surface-treated state, and the surface-untreated (D) inorganic filler and the surface treatment agent are separately separated. Although the (D) inorganic filler may be surface-treated in the composition by blending, it is preferable to blend the (D) inorganic filler which has been surface-treated in advance. By blending the (D) inorganic filler that has been surface-treated in advance, it is possible to prevent deterioration of crack resistance and the like due to the surface treatment agent that may remain when the inorganic filler is blended separately and is not consumed in the surface treatment. In the case of surface treatment in advance, it is preferable to mix a pre-dispersion liquid in which (D) an inorganic filler is pre-dispersed in a solvent or a resin component, and the surface-treated (D) inorganic filler is pre-dispersed in a solvent and the pre-dispersion liquid is prepared. Is sufficiently surface-treated when the surface-untreated inorganic filler (D) is pre-dispersed in a solvent, and then the pre-dispersion liquid is blended into the composition.

In the curable resin composition of the present invention, the inorganic filler (D) preferably has an average particle size of 1 μm or less because it is excellent in crack resistance. More preferably, it is 0.8 μm or less. In the present specification, the average particle size refers to the value of D _50, is a value measured using a Microtrac particle size analyzer manufactured by e.g. NIKKISO Corporation.

Further, the inorganic filler (D) preferably has a maximum particle size of 4.0 μm or less because it reacts efficiently and is excellent in crack resistance and adhesion. More preferably, it is 3.0 μm or less. In the present specification, the maximum particle diameter refers to the value of D _100, is a value measured using a Microtrac particle size analyzer manufactured by e.g. NIKKISO Corporation.

The blending amount of the inorganic filler is preferably 30 to 80% by mass, more preferably 30 to 75% by mass, and preferably 35 to 70% by mass, based on the total solid content of the curable resin composition. More preferred.

(Compound with ethylenically unsaturated bond)
The curable resin composition of the present invention may contain a compound having an ethylenically unsaturated bond, such as a photopolymerizable oligomer or a photopolymerizable vinyl monomer.

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.

As the photopolymerizable vinyl monomer, known and commonly used ones, for example, styrene derivatives such as styrene, chlorostyrene, α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate or vinyl benzoate; vinyl isobutyl ether, 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, (Meta) acrylamides such as methacrylicamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylicamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide; 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, etc. (Meta) acrylic acid esters; hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate; methoxyethyl (meth) acrylate, ethoxyethyl Alkoxyalkylene glycol mono (meth) acrylates such as (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 meta) acrylate, trimethylolpropantri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate; diethylene glycol di (meth) acrylate, triethylene glycol di Polyoxyalkylene glycol poly (meth) acrylates, ethoxylated trimetylolpropan triacrylates, propoxylated trimethylol propantri (meth) acrylates, etc. Ta) Acrylate; Poly (meth) acrylates such as neopentyl glycol hydroxypivalate di (meth) acrylate; Isocyanurate-type poly (meth) acrylates such as tris [(meth) acryloxyethyl] isocyanurate Can be mentioned. These can be used alone or in combination of two or more according to the required characteristics.

The blending amount of the compound having an ethylenically unsaturated bond is preferably 3 to 40 parts by mass with respect to 100 parts by mass of the (A) carboxyl group-containing resin. When it is 3 parts by mass or more, the surface curability is improved, and when it is 40 parts by mass or less, halation is suppressed. More preferably, it is 5 to 30 parts by mass.

(Thermosetting catalyst)
The curable resin composition of the present invention preferably contains a thermosetting catalyst. Examples of such a thermocuring catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. , 1- (2-Cyanoethyl) -2-ethyl-4-methylimidazole and other imidazole derivatives; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N Examples thereof include amine compounds such as -dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipate dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine-isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine-isocyanulic acid adduct can also be used, preferably as these adhesion-imparting agents. A compound that also functions is used in combination with a thermosetting catalyst.

The blending amount of the thermosetting catalyst is preferably 0.05 to 40 parts by mass, and more preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the epoxy resin (B).

(Hardener)
The curable resin composition of the present invention can contain a curing agent. Examples of the curing agent include phenol resins, polycarboxylic acids and their acid anhydrides, cyanate ester resins, active ester resins, maleimide compounds, alicyclic olefin polymers and the like. As the curing agent, one type may be used alone or two or more types may be used in combination.

In the curing agent, the ratio of the functional group capable of a thermosetting reaction such as the epoxy group of the thermosetting resin such as (C) epoxy resin to the functional group in the curing agent that reacts with the functional group is the ratio of the curing agent. It is preferable to blend in a ratio such that the functional group / functional group capable of thermosetting reaction (equivalent ratio) = 0.2 to 3. Within the above range, the balance between storage stability and curability is excellent.

(Colorant)
The curable resin composition of the present invention may contain a colorant. As the colorant, known colorants such as red, blue, green, yellow, black, and white can be used, and any of pigments, dyes, and pigments may be used. However, it is preferable not to contain halogen from the viewpoint of reducing the environmental load and affecting the human body.

The amount of the colorant added is not particularly limited, but is preferably 10 parts by mass or less, particularly preferably 0.1 to 7 parts by mass, with respect to 100 parts by mass of the (A) carboxyl group-containing resin.

(Organic solvent)
The curable resin composition of the present invention may contain an organic solvent for the purpose of preparing the composition, adjusting the viscosity when applied to a substrate or a carrier film, and the like. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethyl benzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol and propylene glycol monomethyl ether. , Dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether and other glycol ethers; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbi Esters such as tall acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, and solvent naphtha are known. Conventional organic solvents can be used. These organic solvents can be used alone or in combination of two or more.

(Other optional ingredients)
Further, the curable resin composition of the present invention may contain other additives known and commonly used in the field of electronic materials. Other additives include thermal polymerization inhibitors, UV absorbers, silane coupling agents, plasticizers, flame retardants, antistatic agents, anti-aging agents, antibacterial / antifungal agents, antifoaming agents, leveling agents, thickening agents. Agents, Adhesion Improving Agents, Tixo Property Improving Agents, Photoinitiating Aids, Sensitizers, Thermoplastic Resins, Organic Fillers, Release Agents, Surface Treatment Agents, Dispersants, Dispersion Aids, Surface Modifiers, Stabilizers , A phosphor and the like.

The curable resin composition of the present invention may contain a thermosetting resin other than the (C) epoxy resin as long as the effects of the present invention are not impaired. The thermosetting resin may be any resin that is cured by heating and exhibits electrical insulation, and examples thereof include epoxy compounds other than (C) epoxy resin, oxetane compounds, melamine resins, and silicone resins. These may be used together.

The curable 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.

Next, the dry film of the present invention has a resin layer obtained by applying and drying the curable resin composition of the present invention on a carrier film. When forming a dry film, first, the curable resin composition of the present invention is diluted with the above organic solvent to adjust the viscosity to an appropriate level, and then a comma coater, a blade coater, a lip coater, a rod coater, and a squeeze coater. , Reverse coater, transfer coater, gravure coater, spray coater, etc., and apply to a uniform thickness on the carrier film. Then, the applied composition is usually dried at a temperature of 40 to 130 ° C. for 1 to 30 minutes to form a resin layer. The coating film thickness is not particularly limited, but is generally selected as appropriate in the range of 3 to 150 μm, preferably 5 to 60 μm after drying.

As the carrier film, a plastic film is used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamide-imide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of the carrier film is not particularly limited, but is generally selected as appropriate in the range of 10 to 150 μm. More preferably, it is in the range of 15 to 130 μm.

After forming the resin layer made of the curable resin composition of the present invention on the carrier film, a peelable cover is further provided on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. It is preferable to laminate the films. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, surface-treated paper, or the like can be used. The cover film may be smaller than the adhesive force between the resin layer and the carrier film when the cover film is peeled off.

In the present invention, the curable resin composition of the present invention may be applied onto the cover film and dried to form a resin layer, and a carrier film may be laminated on the surface thereof. That is, either a carrier film or a cover film may be used as the film to which the curable resin composition of the present invention is applied when producing the dry film in the present invention.

The printed wiring board of the present invention has a cured product obtained from the curable resin composition of the present invention or the resin layer of a dry film. As a method for producing a printed wiring board of the present invention, for example, the curable resin composition of the present invention is adjusted to a viscosity suitable for the coating method using the above organic solvent, and a dip coating method is applied onto the substrate. After coating by a method such as a flow coating method, a roll coating method, a bar coater method, a screen printing method, or a curtain coating method, the organic solvent contained in the composition is volatile-dried (temporarily dried) at a temperature of 60 to 100 ° C. As a result, a tack-free resin layer is formed. Further, in the case of a dry film, a resin layer is formed on the base material by sticking the resin layer on the base material with a laminator or the like so that the resin layer comes into contact with the base material, and then peeling off the carrier film.

The base material includes a printed wiring board and a flexible printed wiring board whose circuit is formed of copper or the like in advance, as well as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, and glass cloth / paper epoxy. , Synthetic fiber epoxy, fluororesin / polyethylene / polyimideene ether, polyphenylene oxide / cyanate, etc. are used for high frequency circuit copper-clad laminates, etc., and all grades (FR-4, etc.) of copper-clad laminates are used. Examples thereof include a plate, a metal substrate, a polyimide film, a PET film, a polyethylene naphthalate (PEN) film, a glass substrate, a ceramic substrate, a wafer plate, and the like.

The volatile drying performed after applying the curable resin composition of the present invention is carried out in a hot air circulation type drying oven, an IR furnace, a hot plate, a convection oven, etc. It can be carried out by using a method of bringing hot air into countercurrent contact and a method of blowing hot air onto a support from a nozzle).

After forming a resin layer on the printed wiring board, it is selectively exposed to active energy rays through a photomask having a predetermined pattern, and the unexposed portion is exposed to a dilute alkaline aqueous solution (for example, 0.3 to 3% by mass sodium carbonate aqueous solution). ) To form a pattern of the cured product. Further, the cured product is adhered by irradiating the cured product with active energy rays and then heat curing (for example, 100 to 220 ° C.), or by irradiating the cured product with active energy rays after heat curing or by performing final finish curing (main curing) only by heat curing. It forms a cured film with excellent properties such as properties and hardness.
When the curable resin composition of the present invention contains a photobase generator, it is preferable to heat it after exposure and before development, and the heating conditions after exposure and before development are, for example, 1 to 1 at 60 to 150 ° C. It is preferable to heat for 60 minutes.

The exposure machine used for the above-mentioned active energy ray irradiation may be a device equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc., and irradiates ultraviolet rays in the range of 350 to 450 nm. Further, a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser based on CAD data from a computer) can also be used. The lamp light source or the laser light source of the direct drawing machine may have a maximum wavelength in the range of 350 to 450 nm. The amount of exposure for image formation varies depending on the film thickness and the like, but is generally 10 to 1000 mJ / cm ² , preferably 20 to 800 mJ / cm ² .

The developing method can be a dipping method, a shower method, a spray method, a brush method, etc., and the developing solution includes potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, etc. Alkaline aqueous solutions such as ammonia and amines can be used.

The curable resin composition of the present invention is suitably used for forming a cured film on a printed wiring board, more preferably used for forming a permanent film, and more preferably a solder resist. It is used to form an interlayer insulating layer and a coverlay. Further, according to the curable resin composition of the present invention, a cured product having excellent crack resistance and insulation reliability can be obtained. Therefore, a printed wiring board having a fine pitch wiring pattern that requires high reliability. For example, it can be suitably used for forming a permanent coating (particularly a solder resist) for a package substrate, particularly FC-BGA.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. In the following, "part" and "%" are all based on mass unless otherwise specified.

[Synthesis of (A) -1 carboxyl group-containing resin]
In an autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device, 119.4 parts of a novolak type cresol resin (Showa Denko Shonor CRG951, OH equivalent: 119.4), potassium hydroxide 1. 19 parts and 119.4 parts of toluene were introduced, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 parts of propylene oxide was gradually added dropwise, and the mixture was reacted at ^{125 to 132 ° C. and 0 to 4.8 kg / cm 2 for 16 hours.} Then, the mixture was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The non-volatile content was 62.1% and the hydroxyl value was 182.2 mgKOH / g (307. A propylene oxide reaction solution of a novolak-type cresol resin at 9 g / eq.) Was obtained. This was an average of 1.08 mol of propylene oxide added per equivalent of phenolic hydroxyl group.
293.0 parts of the propylene oxide reaction solution of the obtained novolak type cresol resin, 43.2 parts of acrylic acid, 11.53 parts of methanesulfonic acid, 0.18 parts of methylhydroquinone and 252.9 parts of toluene were mixed with a stirrer and temperature. It was introduced into a reactor equipped with a meter and an air blowing tube, and air was blown at a rate of 10 ml / min and reacted at 110 ° C. for 12 hours with stirring. As for the water produced by the reaction, 12.6 parts of water was distilled off as an azeotropic mixture with toluene. Then, the mixture was cooled to room temperature, the obtained reaction solution was neutralized with 35.35 parts of a 15% aqueous sodium hydroxide solution, and then washed with water. Then, toluene was distilled off while substituting 118.1 parts of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolak type acrylate resin solution. Next, 332.5 parts of the obtained novolak type acrylate resin solution and 1.22 parts of triphenylphosphine were introduced into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was introduced at a rate of 10 ml / min. With stirring, 60.8 parts of tetrahydrophthalic anhydride was gradually added, reacted at 95 to 101 ° C. for 6 hours, cooled, and then taken out. In this way, a photosensitive (A) -1 carboxyl group-containing resin solution having a solid content of 65% and an acid value of 87.7 mgKOH / g as a solid content was obtained. Hereinafter, this solution of the carboxyl group-containing photosensitive resin is referred to as (A) -1 resin solution.

[Synthesis of (A) -2 carboxyl group-containing resin]
Diethylene glycol monoethyl ether acetate 600 g and orthocresol novolac type epoxy resin (EPICLON N-695 manufactured by DIC, softening point 95 ° C., epoxy equivalent 214, average number of functional groups 7.6) 1070 g (number of glycidyl groups (total number of aromatic rings): 5. 0 mol), 360 g (5.0 mol) of acrylic acid, and 1.5 g of hydroquinone were charged and heated and stirred at 100 ° C. to uniformly dissolve.
Then, 4.3 g of triphenylphosphine was charged, heated to 110 ° C. for 2 hours, then heated to 120 ° C. and further reacted for 12 hours. To the obtained reaction solution, 415 g of aromatic hydrocarbon (Solbesso 150) and 456.0 g (3.0 mol) of tetrahydrophthalic anhydride were charged, and the reaction was carried out at 110 ° C. for 4 hours, and the mixture was cooled and made photosensitive (photosensitive). A) A 2-carboxyl group-containing resin solution was obtained. The solid content of the resin solution thus obtained was 65%, and the acid value of the solid content was 89 mgKOH / g. Hereinafter, this solution of the carboxyl group-containing photosensitive resin is referred to as a resin solution (A) -2.

[Synthesis of (A) -3 carboxyl group-containing resin]
In a flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux cooler, 325.0 parts of dipropylene glycol monomethyl ether as a solvent was heated to 110 ° C., 174.0 parts of methacrylic acid, ε-caprolactone-modified methacrylic acid. (Average molecular weight 314) 174.0 parts, 77.0 parts of methyl methacrylate, 222.0 parts of dipropylene glycol monomethyl ether, and t-butylperoxy2-ethylhexanoate as a polymerization catalyst (Perbutyl O manufactured by Nichiyu Co., Ltd.) ) 12.0 parts of the mixture was added dropwise over 3 hours, and the mixture was further stirred at 110 ° C. for 3 hours to inactivate the polymerization catalyst to obtain a resin solution.
After cooling this resin solution, 289.0 parts of Cyclomer A200 manufactured by Daicel Chemical Industry Co., Ltd., 3.0 parts of triphenylphosphine and 1.3 parts of hydroquinone monomethyl ether are added, the temperature is raised to 100 ° C., and the mixture is stirred. As a result, a ring-opening addition reaction of the epoxy group was carried out to obtain a photosensitive carboxyl group-containing resin solution.
The resin solution thus obtained had a weight average molecular weight (Mw) of 15,000, a solid content of 57%, and an acid value of the solid substance of 79.8 mgKOH / g. Hereinafter, this solution of the carboxyl group-containing photosensitive resin is referred to as a resin solution (A) -3.

(Examples 1 to 17 and Comparative Examples 1 to 3)
Each component shown in Tables 1 to 3 was blended with the carboxyl group-containing resin (mostly 100 parts by mass) of (A) -1 to 3 synthesized above in the ratio shown in Tables 1 to 3, and the examples were prepared. For each comparative example, the curable resin composition was passed through a drying oven at 10 m / min at 60 to 120 ° C. on PET using a die coater, and the solvent was volatilized to obtain a dry film. The blending amounts in Tables 1 to 3 are all numerical values in terms of solids.
The obtained dry film was laminated on a test substrate using a vacuum laminator CVP-300 (manufactured by Nikko Materials Co., Ltd.) to obtain a laminate of curable resin compositions of Examples 1 to 17 and Comparative Examples 1 to 3. .. Here, since the test substrate and the laminating method differ depending on the evaluation items, they are described in the sections of each evaluation item below.
Using DXP-3580 (an ultra-high pressure mercury lamp DI exposure machine manufactured by ORC) on this laminated body, pattern exposure was carried out according to the evaluation items so that the number of curing steps was 10 with a Stuffer 41-step step tablet. Since other exposure conditions differ depending on each evaluation item, they are described in the sections of each evaluation item below.
The PET film was peeled off 10 minutes after the exposure, and development was carried out in a 1 mass% sodium carbonate aqueous solution at 30 ° C. with a development time twice the breakpoint (shortest development time). After that, it was exposed at 2000 mJ on a UV conveyor (Metal halide lamp manufactured by ORC) and cured in a heat circulation type Box furnace at 170 ° C. for 60 minutes to cure the curable resin compositions of Examples 1 to 17 and Comparative Examples 1 to 3. An evaluation substrate for the object was obtained. In addition, developing and curing under the developing and curing conditions described in this paragraph is described as "developing and curing under predetermined conditions" in the section of each evaluation item below.

Regarding the evaluation substrates of the curable resin compositions of Examples 1 to 17 and Comparative Examples 1 to 3 thus prepared, Tg, thermogravimetric reduction, outgas, curing suppression by heat history, adhesion, resolution, HAST Resistance and TCT resistance were evaluated. The results of these evaluations are also shown in Tables 1 to 3.

(Glass transition temperature Tg evaluation)
Each curable resin composition was formed on a copper foil substrate so as to have a film thickness of about 40 μm, and was exposed in a strip-shaped pattern of 50 mm × 3 mm. Then, development and curing were carried out under predetermined conditions.
The cured film of the evaluation substrate obtained as described above was peeled off from the copper foil, and Tg was evaluated. For the measurement, a TMA measuring device (model name: TMA6000 manufactured by Shimadzu Corporation) was used. The evaluation criteria are as follows.
⊚: 180 ° C or higher.
◯: 170 ° C or higher and lower than 180 ° C.
Δ: 160 ° C or higher and lower than 170 ° C.
X: Less than 160 ° C.

(Evaluation of thermogravimetric analysis)
A curable resin composition was formed on a plated copper substrate treated with CZ-8101B under the condition of an etching rate of 1.0 μm / m ² so as to have a film thickness of about 15 μm, and the entire surface was exposed. Then, development and curing were carried out under predetermined conditions.
Approximately 5 mg of the cured coating powder sample of the obtained evaluation substrate was sampled, heated at 140 ° C. for 90 minutes with a TGDTA apparatus manufactured by Rigaku Co., Ltd., and evaluated at a weight loss rate after reaching 140 ° C. The evaluation criteria are as follows.
⊚: Less than 0.025%.
◯: 0.025% or more and less than 0.050%.
Δ: 0.050% or more and less than 0.075%.
X: 0.075% or more.

(Outgas evaluation)
A curable resin composition was formed on a plated copper substrate treated with CZ-8101B under the condition of an etching rate of 1.0 μm / m ² so as to have a film thickness of about 15 μm, and the entire surface was exposed. Then, development and curing were carried out under predetermined conditions.
Approximately 1 mg of the obtained cured film powder sample of the evaluation substrate is sampled and heated under the following thermal extraction conditions. After cold trapping the volatilized component, it was rapidly heated and introduced into GC / MS for evaluation. The following evaluation devices were used, and the extraction conditions and evaluation criteria were as follows.
(1) Evaluation device Heat desorption device: TDU manufactured by Gesuteru Co., Ltd.
GC: Agilent Technologies, Inc. 6890N
MSD: Agilent Technologies Co., Ltd. 5973N
(2) Extraction conditions Thermal extraction conditions: 220 ° C., 10 minutes.
(3) Evaluation criteria ◎: Less than 0.020%.
◯: 0.020% or more and less than 0.040%.
Δ: 0.040% or more and less than 0.060%.
X: 0.060% or more.

(Evaluation of hardening suppression by heat history)
Each curable resin composition was formed on a copper foil substrate so as to have a film thickness of about 40 μm, and was exposed in a strip-shaped pattern of 50 mm × 5 mm. Then, development and curing were carried out under predetermined conditions.
The result of peeling the cured film of the evaluation substrate obtained as described above from the copper foil and measuring Tg using DMA (RSA-G2 manufactured by TA) was defined as (1), and the evaluation obtained as described above was also made. The substrate was cured again under the condition of 150 ° C. for 24 hours, and then the cured film of the evaluation substrate was peeled off from the copper foil in the same manner, and the Tg was measured using DMA (RSA-G2 manufactured by TA). ), And the evaluation was carried out based on the numerical difference between (1) and (2). The evaluation criteria are as follows.
⊚: Less than 15 ° C.
◯: 15 ° C or higher and lower than 30 ° C.
Δ: 30 ° C. or higher and lower than 45 ° C.
X: 45 ° C. or higher.

(Adhesion evaluation)
A curable resin composition was formed on a copper foil treated with CZ-8201B under a condition of an etching rate of 0.5 μm / m ² so as to have a film thickness of about 20 μm, and the entire surface was exposed. Then, development and curing were carried out under predetermined conditions. Then, a thermosetting adhesive Araldite (manufactured by Nichiban Co., Ltd.) was formed on the surface of the curable resin composition, adhered to a FR-4 substrate, and cured under the condition of 80 ° C. for 6 hours. Then, the evaluation substrate was cut at intervals of 20 mm, and both sides were peeled off so that the Cu foil width became 10 mm width to prepare an evaluation strip. This evaluation strip was subjected to a 90 ° peel test using a tensile tester (model name: AGS-G 100N manufactured by Shimadzu Corporation) to evaluate the adhesion. The evaluation criteria are as follows.
⊚: 6.0 N / cm or more.
◯: 5.0 or more and less than 6.0 N / cm.
Δ: 4.0 or more and less than 5.0 N / cm.
X: Less than 4.0 N / cm.

(Resolution evaluation)
A curable resin composition was formed on a plated copper substrate treated with CZ-8101B under a condition of an etching rate of 1.0 μm / m ² so as to have a film thickness of about 15 μm, and exposure was performed with various aperture patterns. After that, development was carried out under predetermined conditions and curing was carried out under evaluation conditions.
The opening diameter of the evaluation substrate obtained as described above was observed, and it was confirmed that no halation or undercut occurred and the evaluation was performed. The evaluation criteria are as follows.
⊚: Good opening diameter at 60 μm.
◯: Good opening diameter at 70 μm.
Δ: Good opening diameter at 80 μm.
X: A good opening diameter cannot be obtained at 80 μm. Or development is not possible.

(HAST resistance evaluation)
The curable resin composition was applied to a substrate on which a comb-shaped pattern of L / S = 20/15 μm was formed, which was treated with CZ-8101B under the condition of an etching rate of 1.0 μm / m ^{2, so that the film thickness on Cu was about 15 μm.} It was formed and exposed to the entire surface. Then, development and curing were carried out under predetermined conditions.
After that, the electrodes were connected and the HAST test was carried out under the conditions of 130 ° C., 85% and 5V. The evaluation criteria are as follows.
◎: Pass in 400 hours.
◯: Pass in 350 hours.
Δ: Pass in 300 hours.
X: NG within 250 hours.

(TCT resistance)
A curable resin composition was formed on a package substrate treated with CZ-8101B under a condition of an etching rate of 1.0 μm / m ² so that the thickness on Cu was about 15 μm, and SRO 80 μm was exposed on a copper pad. rice field. Then, development and curing were carried out under predetermined conditions. Then, Au plating treatment, solder bump formation, and Si chip were mounted to obtain an evaluation substrate.
The evaluation substrate obtained as described above was placed in a thermal cycle machine in which a temperature cycle was performed between −65 ° C. and 150 ° C., and TCT (Thermal Cycle Test) was performed. Then, the surface of the cured film at 600 cycles, 800 cycles and 1000 cycles was observed. The judgment criteria were as follows.
⊚: No abnormality in 1000 cycles.
◯: No abnormality in 800 cycles. Cracks occur in 1000 cycles.
Δ: No abnormality in 600 cycles. Cracks occur in 800 cycles.
X: Cracks occur in 600 cycles.

The components used in each of the examples and comparative examples shown in Tables 1 to 3 are as follows.
(* 1): The above-mentioned (A) -1 carboxyl group-containing resin (carboxylic acid equivalent 640)
(* 2): The above-mentioned (A) -2 carboxyl group-containing resin (carboxylic acid equivalent 630)
(* 3): The above-mentioned (A) -3 carboxyl group-containing resin (carboxylic acid equivalent 703)
(* 4): Techmore VG3101L manufactured by Mitsui Chemicals, Inc. (an epoxy resin having the structure of the above formula (I), epoxy equivalent 210, Gardner color number 2).
(* 5): NC-6300H manufactured by Nippon Kayaku Co., Ltd. (Epoxy resin having the structure of the above formula (I), epoxy equivalent 232, Gardner color number 2)
(* 6): TEPIC-VL manufactured by Nissan Chemical Industries, Ltd. (a liquid trifunctional epoxy resin having an isocyanul ring, epoxy equivalent 135, Gardner color number 1)
(* 7): TEPIC-FL manufactured by Nissan Chemical Industries, Ltd. (a liquid trifunctional epoxy resin having an isocyanul ring, epoxy equivalent 170, Gardner color number 1).
(* 8): NC-7000L manufactured by Nippon Kayaku Co., Ltd. (polyfunctional epoxy resin containing aromatic (naphthalene) skeleton, epoxy equivalent 230, Gardner color number> 12)
(* 9): N-730-A manufactured by DIC Co., Ltd. (2.5 functional epoxy resin containing aromatic (phenol novolac type) skeleton, epoxy equivalent 176, Gardner color number 1)
(* 10): HP-4032 manufactured by DIC Co., Ltd. (bifunctional epoxy resin containing aromatic (naphthalene) skeleton, epoxy equivalent 142, Gardner color number> 12)
(* 11): Omnirad TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) manufactured by IGM Resins.
(* 12): Omnirad 907 (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one) manufactured by IGM Resins.
(* 13): Irgacure OXE02 manufactured by BASF Japan Ltd. (Etanon, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] -1- (o-acetyloxime)
(* 14): TOE-04-A3 (oxime ester type) manufactured by Nippon Kagaku Kogyo Co., Ltd.
(* 15): A silica-dispersed product obtained by the following production method. 50 g of spherical silica particles (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm), 48 g of PMA as a solvent, and 2 g of a dispersant (BYK-111) were uniformly dispersed.
(* 16): Barium sulfate dispersed product obtained by the following production method. A water slurry of 50 g of barium sulfate particles (precipitating barium 100 manufactured by Sakai Chemical Industry Co., Ltd.) was heated to 70 ° C., and then 1% of a 10% sodium silicate aqueous solution was added to the silica particles in terms of silica particles. Hydrochloric acid was added to this slurry to adjust the pH to 4, and the mixture was aged for 30 minutes. Further, while maintaining the pH at 7 ± 1 with hydrochloric acid, a 20% _{aqueous solution of sodium aluminate (NaAlO 2} ) was added to the silica particles with alumina (alumina (NaAlO 2). Al ₂ O ₃ ) 5% was added in terms of conversion. After that, a 20% sodium hydroxide water bath solution was added to adjust the pH to 7, and the mixture was aged for 30 minutes. Then, the slurry was washed with filtered water using a filter press and vacuum dried to obtain a solid substance of barium sulfate particles coated with a hydrated oxide of silicon and a hydrated oxide of aluminum. 50 g of barium sulfate particles coated with a hydrated oxide of silicon obtained in the same manner as above, 48 g of PMA as a solvent, and 2 g of a dispersant (BYK-111) were uniformly dispersed.
(* 17): Alumina-dispersed product obtained by the following manufacturing method. 50 g of spherical alumina particles (ASFP-20 manufactured by Denka Co., Ltd., average particle size: 300 nm), 48 g of PMA as a solvent, and 2 g of a dispersant (BYK-111) were uniformly dispersed.
(* 18): A silica-dispersed product obtained by the following production method. 50 g of spherical silica particles (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm), 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) are uniformly dispersed. I let you.
(* 19): A silica-dispersed product obtained by the following production method. After raising the temperature of 50 g of water slurry of spherical silica particles (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm) to 70 ° C., 1% of a 10% sodium silicate aqueous solution is added to the silica particles in terms of silica particles. Added. Hydrochloric acid was added to this slurry to adjust the pH to 4, and the mixture was aged for 30 minutes. Further, while maintaining the pH at 7 ± 1 with hydrochloric acid, a 20% _{aqueous solution of sodium aluminate (NaAlO 2} ) was added to the silica particles with alumina (alumina (NaAlO 2). Al ₂ O ₃ ) 5% was added in terms of conversion. After that, a 20% sodium hydroxide water bath solution was added to adjust the pH to 7, and the mixture was aged for 30 minutes. Then, the slurry was washed with filtered water using a filter press and vacuum dried to obtain a solid material of silica particles coated with a hydrated oxide of silicon and a hydrated oxide of aluminum. 50 g of silica particles coated with a hydrated oxide of silicon obtained in the same manner as above, 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) are uniformly dispersed. Distributed.
(* 20): DPHA (dipentaerythritol hexaacrylate) manufactured by Nippon Kayaku Co., Ltd.
(* 21): Phthalocyanine blue
(* 22): Chromophthal yellow
(* 23): Melamine (* 24): DICY (dicyandiamide)

From the results shown in Tables 1 to 3, according to the curable resin composition of the present invention, a solder resist having high adhesion, high resolution, high insulation reliability (HAST resistance), and high crack resistance (TCT resistance) can be obtained. Obtained from the curable resin composition having excellent resistance to high-temperature standing, which generates less outgas when a package substrate is subjected to a high-temperature and long-term heat history while satisfying the required performance, that is, can suppress weight loss. It can be seen that a cured product having a resin layer to be obtained can be obtained.

Claims (8)

(A) Carboxyl group-containing resin,
(B) Epoxy resin,
A curable resin composition containing (C) a photopolymerization initiator and (D) an inorganic filler.
The number of Gardner colors of (B) epoxy resin is 3 or less, and (B) epoxy resin is
(B-1) An epoxy resin having the structure of the following formula (I) and

(B-2) A liquid trifunctional epoxy resin having an isocyanul ring and
A curable resin composition comprising. The curable resin composition according to claim 1, wherein the content of the inorganic filler (D) is 30 to 70% by mass. The curable resin composition according to claim 1, wherein the (C) photopolymerization initiator is an oxime ester. The curable resin composition according to claim 1, wherein the liquid trifunctional epoxy resin having the (B-2) isocyanul ring is an epoxy resin having the structure of the following formula (II).

A dry film having a resin layer obtained by applying the curable resin composition according to claim 1 to a film and drying the film. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 4 or the resin layer of the dry film according to claim 5. A printed wiring board comprising the cured product according to claim 6. An electronic component comprising the printed wiring board according to claim 7.