WO2020202656A1

WO2020202656A1 - Curable resin composition, dry film, cured product, and electronic component

Info

Publication number: WO2020202656A1
Application number: PCT/JP2019/049159
Authority: WO
Inventors: 千穂植田; 岡田　和也; 知哉工藤; 沙和子嶋田; 将太郎種
Original assignee: 太陽インキ製造株式会社
Priority date: 2019-03-29
Filing date: 2019-12-16
Publication date: 2020-10-08
Also published as: KR20210148177A; JP2020164760A; TWI814970B; TW202035595A; CN113631603A

Abstract

Provided are: a curable resin composition from which a cured product having excellent resolution and embedding properties of high-density wiring patterns is obtained; a dry film having a resin layer obtained from the composition; a cured product of the composition or the resin layer of the dry film; and an electronic component having the cured product. The curable resin composition is characterized by including (A) a photocurable resin, (B) a photopolymerization initiator, and (C) silica, wherein (A) the photocurable resin has a refractive index of 1.50-1.65 on a D line as measured at 25 ˚C, and (C) the silica is covered with an organic alkoxysilane having a refractive index of 1.50-1.65 on a D line as measured at 25 ˚C.

Description

Curable resin compositions, dry films, cured products, and electronic components

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

For curable resin compositions used for solder resists and the like of semiconductor packages, there is an increasing demand for resolution accuracy due to fine pitch (Fine Pitch). On the other hand, since it is necessary to have resistance to thermal stress, the coefficient of linear thermal expansion is controlled by adding a highly heat-resistant resin or an inorganic material. As the inorganic material used there, silica has been conventionally used not only in terms of physical properties such as low CTE and crack resistance, but also in terms of ease of use such as cost and specific gravity.
For example, Patent Document 1 discloses a photosensitive resin composition in which two kinds of inorganic fillers having a specific refractive index and organic fillers having a specific particle size are combined to give high resolution and a low coefficient of linear expansion. There is.

Japanese Patent No. 621060

However, even with the photosensitive resin composition described in Patent Document 1, it has been difficult to obtain sufficiently high resolution to meet the demand for high resolution accuracy due to fine pitching.
Further, by blending silica, the viscosity of the composition is increased, the embedding accuracy of the high-density wiring pattern is inferior, and there is a problem that the insulation reliability is lowered.
Therefore, an object of the present invention is a curable resin composition capable of obtaining a cured product having excellent resolution and embedding property of a high-density wiring pattern, a dry film having a resin layer obtained from the composition, the composition or the present invention. An object of the present invention is to provide a cured product of a resin layer of a dry film and an electronic component having the cured product.

The present inventors have diligently studied the surface treatment of silica in order to realize the above object. As a result, the present inventors have a refractive index of 1.50 to 1.65 at the D line (25 ° C) as opposed to a photocurable resin having a refractive index of 1.50 to 1.65 at the D line (25 ° C). It has been found that the above-mentioned problems can be solved by blending silica coated with 65 organic alkoxysilanes, 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 photocurable resin, (B) a photopolymerization initiator, and (C) silica, and the above-mentioned (A) light. The refractive index of the curable resin in the D line measured at 25 ° C. is 1.50 to 1.65, and the refractive index of the silica (C) in the D line measured at 25 ° C. is 1.50 to 1.65. It is characterized in that it is coated with the organic alkoxysilane.

In the curable resin composition of the present invention, it is preferable that the organic alkoxysilane has a cardo structure.

In the curable resin composition of the present invention, the silica (C) is coated with at least two kinds of the organic alkoxysilanes, or is coated with the organic alkoxysilanes and organic alkoxysilanes other than the organic alkoxysilanes. Is preferable.

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.

The cured product of the present invention is characterized by being obtained by curing the curable 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, a curable resin composition capable of obtaining a cured product having excellent resolution and embedding property of a high-density wiring pattern, a dry film having a resin layer obtained from the composition, the composition or the dry product. A cured product of the resin layer of the film and an electronic component having the cured product can be provided.

The curable resin composition of the present invention is a curable resin composition containing (A) a photocurable resin, (B) a photopolymerization initiator, and (C) silica, and the (A) photocurable resin composition. The refractive index of the resin in the D line measured at 25 ° C. is 1.50 to 1.65, and the refractive index of the (C) silica in the D line measured at 25 ° C. is 1.50 to 1.65. It is characterized in that it is coated with an organic alkoxysilane.
Conventionally, the refractive index of silica at D line (25 ° C.) is 1.42, and the higher the filling, the more scattered light at the interface, and it is difficult to obtain a small-diameter aperture.
On the other hand, the present invention has a photocurable resin having a refractive index of 1.50 to 1.65 at the D line (25 ° C.) and a refractive index of 1.50 to 1.65 at the D line (25 ° C.). By using silica coated with a certain organic alkoxysilane in combination, the resolvability and the embedding property of a high-density wiring pattern can be improved.
That is, in the present invention, (A) the difference in refractive index between the photocurable resin having the refractive index and the silica surface coated with the specific organic alkoxysilane having the refractive index is relatively close, so that the active energy It is possible to prevent line scattering (Rayleigh scattering and Mie scattering). As a result, theoretically, the transmittance of the active energy ray is maximized, and in the present invention, good deep curability can be obtained. Therefore, a cured product having excellent resolution can be obtained even when highly filled with silica.

In the present invention, the difference between the refractive index of (A) the photocurable resin and the refractive index of (B) the organic alkoxysilane coating silica is preferably 0.10 or less, and preferably 0.08 or less. It is more preferably 0.06 or less, further preferably 0.03 or less, and particularly preferably 0.03 or less. Here, when there are a plurality of (A) photocurable resin and (C) organic alkoxysilanes that coat silica, the refractive index of either (A) photocurable resin and (B) organic that coats silica The difference from the refractive index of alkoxysilane may be 0.10 or less. However, when there are a plurality of (A) photocurable resins, the refractive index of (A) the photocurable resin contained most in the (A) photocurable resin in terms of mass% and (C) silica are coated. It is preferable that the difference from the refractive index of the organic alkoxysilane is 0.10 or less.

Further, in the present invention, the organic alkoxysilane preferably has a cardo structure such as a fluorene skeleton. By blending silica coated with an organic alkoxysilane having a cardo structure, a cured product having more excellent heat resistance can be obtained, and a roughened-less substrate or a silicon substrate (that is, a substrate having a small anchor effect) can be obtained. It also has excellent adhesion.

In the present invention, (A) a photocurable resin using a phenol resin described later as a photocurable resin as a starting material, a photocurable copolymer resin having a maleimide structure, and (C) a specific organic alkoxysilane are coated. By using the above-mentioned silica together, it was confirmed that the heat resistance and the thermal stability were improved in addition to the improvement of the resolution and the further flowability.

The curable resin composition of the present invention is exposed to ultraviolet rays (around 400 nm), and the refractive index is controlled by using the widely generally shown refractive index of D line. The curable resin composition of the present invention has a (A) photocurable resin having a refractive index of 1.50 to 1.65 on the D line and a refractive index of 1.50 to 1.65 on the D line. Since excellent resolution could be obtained by using (C) silica coated with organic alkoxysilane in combination, the object of the present invention could be obtained by adjusting the refractive index at the D line. It turns out that it can be fully achieved.

The components of the curable resin composition of the present invention will be described below.

[(A) Photocurable resin]
The photocurable resin (A) is a photocurable resin having a refractive index of 1.50 to 1.65 at the D line (25 ° C.), and is a compound having one or more ethylenically unsaturated groups in the molecule. Is preferably used. As the compound having an ethylenically unsaturated group, a known and commonly used compound may be used, and a polymer such as an alkali-soluble resin having an ethylenically unsaturated group, a photopolymerizable oligomer which is a photosensitive monomer, or a photopolymerizable vinyl monomer may be used. Etc., and may be a radically polymerizable monomer or a cationically polymerizable monomer. Examples of the ethylenically unsaturated group include a vinyl group and a (meth) acryloyl group. As used herein, the term (meth) acryloyl group is a general term for acryloyl groups, methacryloyl groups, and mixtures thereof, and the same applies to other similar expressions.

When the composition of the present invention is an alkali-developed type, the (A) photocurable resin is preferably an alkali-soluble resin. When the photocurable resin (A) is an alkali-soluble resin, a cured product having particularly excellent resolution can be obtained. The alkali-soluble resin may be any resin having an alkali-soluble group, and the alkali-soluble group is, for example, any one of a phenolic hydroxyl group, a thiol group and a carboxyl group. Examples of the alkali-soluble resin include compounds having two or more phenolic hydroxyl groups, carboxyl group-containing resins, compounds having phenolic hydroxyl groups and carboxyl groups, and compounds having two or more thiol groups, and among them, excellent developability. Therefore, a carboxyl group-containing resin is preferable. Among the carboxyl group-containing resins, a photocurable resin using a phenol resin as a starting material, a photocurable copolymer resin having a maleimide structure, and a photocurable resin having an epoxy acrylate structure are preferable. As the photocurable resin (A), one type may be used alone, or two or more types may be used in combination.

Specific examples of the (A) photocurable resin include, but are not limited to, 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 or α-methylstyrene, and glycidyl (meth) acrylate or α- A carboxyl group-containing photosensitive resin having a copolymerization structure, obtained by adding a compound having one epoxy group and one or more (meth) acryloyl groups to a molecule such as methylglycidyl (meth) acrylate.

(2) Obtained by reacting a diisocyanate such as an aromatic diisocyanate, a carboxyl group-containing dialcohol compound, a diol compound, and a compound having one isocyanate group and one or more (meth) acryloyl groups in the molecule. A carboxyl group-containing photosensitive resin having a urethane structure.

(3-1) Contains a carboxyl group having a urethane structure by a double addition reaction of a diisocyanate, a (meth) acrylate of a bifunctional epoxy resin or a partially acid anhydride modified product thereof, a carboxyl group-containing dialcohol compound, and a diol compound. Photosensitive resin.
(3-2) Carboxylic acid having a urethane structure formed by adding a compound having one epoxy group and one or more (meth) acryloyl groups in the molecule to the carboxyl group-containing photosensitive resin of (3-1). Group-containing photosensitive resin.
(3-3) Diisocyanate, (meth) acrylate of bifunctional epoxy resin or partially acid anhydride modified product thereof, carboxyl group-containing dialcohol compound, diol compound, one hydroxyl group in the molecule and one or more (Meta) A carboxyl group-containing photosensitive resin having a urethane structure obtained by reacting with a compound having an acryloyl group.
(3-4) Diisocyanate, (meth) acrylate of bifunctional epoxy resin or partially acid anhydride modified product thereof, carboxyl group-containing dialcohol compound, diol compound, one isocyanate group in the molecule and one or more. A carboxyl group-containing photosensitive resin having a urethane structure obtained by reacting with a compound having a (meth) acryloyl group.

(4) An unsaturated monocarboxylic acid such as (meth) acrylic acid is reacted with a polyfunctional epoxy resin, and dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride is added to the hydroxyl group existing in the side chain. Carboxylic anhydride-containing photosensitive resin with an added substance.

(5) A carboxyl group obtained by reacting a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl group of a bifunctional epoxy resin with epichlorohydrin with an unsaturated group-containing monocarboxylic acid, and adding a dibasic acid anhydride to the generated hydroxyl group. Containing photosensitive resin.

(6) 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 an unsaturated mono Polybasic acid anhydrides such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and adipic anhydride with respect to the alcoholic hydroxyl group of the reaction product obtained by reacting with a carboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting with.

(7) Reaction production obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with alkylene oxide such as ethylene oxide and 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.

(8) 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.

(9) Maleimide or maleimide derivatives such as N-phenylmaleimide and N-benzylmaleimide, unsaturated carboxylic acids such as (meth) acrylic acid, and unsaturated group-containing compounds having a hydroxyl group such as hydroxyalkyl (meth) acrylate. , Styrene, α-methylstyrene, α-chlorostyrene, vinyltoluene and other unsaturated group-containing compounds having an aromatic ring as monomers in a carboxyl group-containing copolymer resin, glycidyl (meth) acrylate, α-methyl Carboxylic group-containing photosensitive having a copolymerization structure, which is formed by adding a compound having one epoxy group and one or more (meth) acryloyl groups to a molecule such as glycidyl (meth) acrylate or epoxycyclohexylmethyl (meth) acrylate. Sex resin.

(10) One epoxy in a molecule such as glycidyl (meth) acrylate, α-methylglycidyl (meth) acrylate, and epoxycyclohexylmethyl (meth) acrylate in the carboxyl group-containing photosensitive resin of (2) to (8). A carboxyl group-containing photosensitive resin obtained by adding a compound having a group and one or more (meth) acryloyl groups.

(A) When the photocurable resin is an alkali-soluble resin, the acid value thereof is appropriately in the range of 40 to 200 mgKOH / g, and more preferably in the range of 45 to 120 mgKOH / g. When the acid value of the photocurable resin (A) is 40 mgKOH / g or more, alkaline development becomes easy, while drawing a normal cured product pattern of 200 mgKOH / g or less becomes easy, which is preferable.

Examples of the photopolymerizable oligomer include epoxy (meth) acrylates such as phenol novolac epoxy (meth) acrylate, cresol novolac epoxy (meth) acrylate, and bisphenol type epoxy (meth) acrylate, epoxy urethane (meth) acrylate, and polyester (meth) acrylate. And so on.

Examples of the photopolymerizable vinyl monomer include known and commonly used styrene derivatives such as styrene, chlorostyrene and α-methylstyrene, allyl compounds such as triallyl isocyanurate, diallyl phthalate and diallyl isophthalate, and phenyl (meth). Examples thereof include esters of (meth) acrylic acid such as acrylate and phenoxyethyl (meth) acrylate, and isocyanurate-type poly (meth) acrylates such as tris [(meth) acryloxyethyl] isocyanurate.

(A) The refractive index of the photocurable resin at the D line (25 ° C.) is preferably 1.52 or more, and more preferably 1.54 or more.

The blending amount of the (A) photocurable resin is, for example, 10 to 50% by mass with respect to the total solid content of the curable resin composition. The curable resin composition of the present invention may contain a photocurable compound having a refractive index of less than 1.50 at the D line (25 ° C.). For example, the blending amount of the photocurable compound having a refractive index of less than 1.50 is a combination of a photocurable compound having a refractive index of less than 1.50 and a photocurable resin having a refractive index of 1.50 to 1.65. It may be less than 50% by mass with respect to the total amount. Examples of the photocurable compound having a refractive index of less than 1.50 include hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and pentaerythritol tri (meth) acrylate; methoxyethyl. Alkoxyalkylene glycol mono (meth) acrylates such as (meth) acrylate and ethoxyethyl (meth) acrylate; ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1 , 6-Hexanediol di (meth) acrylate, trimethylolpropantri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate and other alkylene polyol poly (meth) acrylate; diethylene glycol di (meth) acrylate. ) Polyoxyalkylene glycol poly (meth) acrylates such as acrylates, triethylene glycol di (meth) acrylates, ethoxylated trimetylolpropan triacrylates, propoxylated trimethylol propantri (meth) acrylates; neopentyl glycol hydroxybivariate Examples thereof include poly (meth) acrylates such as ester di (meth) acrylate.

[(B) Photopolymerization Initiator]
As the photopolymerization initiator (B), any photopolymerization initiator known as a photopolymerization initiator or a photoradical generator can be used.

Examples of the photopolymerization initiator (B) include bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, and 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) -bisacylphosphine oxides such as phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyl Monoacylphosphine oxides such as phenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 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-propane-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one and other hydroxyacetophenones; benzoyl, benzyl , Benzoyl methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether and other benzoins; benzoin alkyl ethers; benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'- Benzoyls such as 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-morpholinophenyl) ) -Butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N, N-dimethylaminoacetophenone, etc. Acetphenones; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone , 2-Methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylantraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone and other anthraquinones; acetphenone dimethyl ketal, benzyl dimethyl ketal and other ketals; ethyl Orthoperic acid esters such as -4-dimethylaminobenzoate, 2- (dimethylamino) ethylbenzoate, 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; (eta ^{5-2,4-cyclopentadiene-1-yl)} - bis (2,6-difluoro-3-(1H-pyrrol-1-yl) phenyl) titanium, bis (cyclopentadienyl) - bis [2 , 6-Difluoro-3- (2- (1-pyr-1-yl) ethyl) phenyl] Titanocenes such as titanium; phenyldisulfide 2-nitrofluorene, butyroine, anisoine ethyl ether, azobisisobutyronitrile, Examples thereof include tetramethylthiuram disulfide. As the photopolymerization initiator, one type may be used alone, or two or more types may be used in combination.

The blending amount of the (B) photopolymerization initiator is, for example, 0.1 to 30% by mass with respect to the total solid content of the curable resin composition.

[(C) Silica]
In the present invention, (C) silica is coated with an organic alkoxysilane having a refractive index of 1.50 to 1.65 at the D line (25 ° C.). Examples of silica include fused silica, spherical silica, amorphous silica, crystalline silica, sol silica and the like, but spherical silica is preferable.

The organic alkoxysilane having a refractive index of 1.50 to 1.65 on the D line (25 ° C.) is not particularly limited, and a known and commonly used organic alkoxysilane may be used. For example (hereinafter, the refractive index is the refractive index in the measurement of D line (25 ° C., also referred to as sodium D line)), KBM-202SS (dimethoxydiphenylsilane: refractive index 1.54) manufactured by Shinetsu Chemical Industry Co., Ltd., X-12. 1156 (organosilane containing methoxy group and mercapto group: refractive index 1.52), X-12-1154 (organosilane containing methoxy group and mercapto group :: refractive index: 1.51), KR-511 (methoxy group and vinyl) Group-containing siloxane: Refractive index 1.51), X-12-1159L (Methoxy group and isocyanate group-containing organosilane: Refractive index 1.50), KBM-573 (Amino group-containing N-phenyl-3-aminopropyltrimethoxysilane) : Refractive index 1.50), KBM-1403 (Styryltrimethoxysilane: Refractive index 1.50), Osaka Gas Chemical Co., Ltd. SC-001 (Fluolene-containing silane: Refractive index 1.56), SC-003 (Fluorene-containing Silane: Refractive index 1.53) and the like. Of these, an alkoxysilane having an aromatic ring is preferable, and an organic alkoxysilane having a cardo structure is particularly preferable. Further, as described above, from the viewpoint of heat resistance, an organic alkoxysilane having a fluorene skeleton such as SC-001 or SC-003 is preferable, and an organic alkoxysilane having a fluorene skeleton having a cardo structure is more preferable. The alkoxy group of the organic alkoxysilane is, for example, an alkoxy group having 1 to 5 carbon atoms. The organic alkoxysilane may be used alone or in combination of two or more depending on the refractive index of the (A) photocurable resin.

Examples of the organic alkoxysilane having a fluorene skeleton having a cardo structure include organic alkoxysilanes represented by the following formulas (1-1) and (1-2).

(In the equation, n and m each independently indicate an integer of 1 to 6.)

Examples of commercially available products of the organic alkoxysilane represented by the above formula (1-1) include Ogsol SC-001 manufactured by Osaka Gas Chemical Co., Ltd. Examples of commercially available products of the organic alkoxysilane represented by the above formula (1-2) include Ogsol SC-003 manufactured by Osaka Gas Chemical Co., Ltd.

The organic alkoxysilane may have a curable reactive group. The curable reactive group is not particularly limited as long as it is a group that cures with a component (for example, a photocurable resin or a thermosetting resin) blended in the curable resin composition, and even a photocurable reactive group is thermosetting. It may be a sexual reactive group.

The coating method is not particularly limited, and for example, a known and commonly used method such as a method of treating silica using the organic alkoxysilane as a silane coupling agent may be used.

The coating with an organic alkoxysilane having a refractive index of 1.50 to 1.65 on the D line (25 ° C.) is, for example, 1 to 50 parts by mass with respect to 100 parts by mass of silica.

The silica (C) is preferably coated with at least two kinds of the organic alkoxysilanes, or with an organic alkoxysilane other than the organic alkoxysilanes and the organic alkoxysilanes. By blending the silica coated in this way, a cured product having low CTE and excellent cold resistance can be obtained. Such coating treatment may be performed before, after, or at the same time as the coating treatment with the organic alkoxysilane.

The organic alkoxysilane having a refractive index of 1.50 to 1.65 at the D line (25 ° C.) may or may not have a curable reactive group. When the organic alkoxysilane having a refractive index of 1.50 to 1.65 at the D line (25 ° C.) does not have a curable reactive group, it is preferable to use it in combination with an organic alkoxysilane having a curable reactive group. When used in this way, heat resistance, thermal stability and crack resistance during a cold cycle are improved.

Examples of the organic silane other than the organic alkoxysilane include KBM-502 (refractive index: 1.43), KBM-503 (refractive index: 1.43), KBE-502 (refractive index: 1.43), and KBE-503. (Refractive index: 1.43), KBM-5803 (refractive index: 1.44), methacrylsilane such as KR-503 (refractive index: 1.45), KBM-5103 (refractive index: 1.43), X 12-1048 (refractive index: 1.45), X-12-1050 (refractive index: 1.48), KR-513 (refractive index: 1.45), KBM-1003 (refractive index: 1.39) Examples thereof include silane having an equal refractive index of less than 1.50. The organic silane other than the organic alkoxysilane is preferably a silane having a reactive group with the component (A). Of these, methacrylic silane is preferable from the viewpoint of physical properties such as tensile strength. In addition, epoxy silane such as KBM-403 (refractive index: 1.43) may be mixed and added to control the refractive index.

When further coating with an organic silane other than the organic alkoxysilane, the coating with an organic silane other than the organic alkoxysilane is 1 to 50 parts by mass with respect to 100 parts by mass of silica.

Note that (C) silica may be further coated with an inorganic substance. The inorganic substance is not particularly limited, and examples thereof include silicon hydrated oxide, aluminum hydrated oxide, zirconium hydrated oxide, zinc hydrated oxide, and titanium hydrated oxide.

When further coating with an inorganic substance, the coating with the inorganic substance is, for example, 1 to 40 parts by mass with respect to 100 parts by mass of silica.

The average particle size of (C) silica is, for example, 0.01 to 0.8 μm. Here, in the present specification, the average particle size of (C) silica is the average particle size (D50) including not only the particle size of the primary particles but also the particle size of the secondary particles (aggregates), and is a laser. It is a value of D50 measured by a diffraction method. Examples of the measuring device by the laser diffraction method include Microtrac MT3300EXII manufactured by Microtrac Bell.

The average particle size of (C) silica may be adjusted, and for example, it is preferable to pre-disperse it with a bead mill or a jet mill. Further, the inorganic filler is preferably blended in a slurry state, and by blending in a slurry state, high dispersion is facilitated, aggregation is prevented, and handling is facilitated.

(C) Silica may be used alone or in combination of two or more. The blending amount of silica (C) may be, for example, 10% by mass or more, further 20% by mass or more, or even 30% by mass or more, based on the total solid content of the curable resin composition. The upper limit of the amount of silica blended is, for example, 80% by mass or less.

The curable resin composition of the present invention may contain a known and commonly used inorganic filler other than (C) silica as long as the effects of the present invention are not impaired. Examples of such an inorganic filler include silica other than silica coated with organic alkoxysilane having a refractive index of 1.50 to 1.65 at D line (25 ° C.), Neuburg silica clay, aluminum hydroxide, and glass. Powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, aluminum hydroxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, mineral wool, aluminum silicate, calcium silicate, Examples include inorganic fillers such as zinc flower.

(Thermosetting resin)
The curable resin composition of the present invention can contain a thermosetting resin. The thermosetting resin improves the heat resistance of the cured product and also improves the adhesion to the substrate. As the thermosetting resin, known and commonly used thermosetting resins such as isocyanate compounds, blocked isocyanate compounds, amino resins, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, polyfunctional oxetane compounds, and episulfide resins can be used. .. Among these, epoxy compounds, polyfunctional oxetane compounds, and compounds having two or more thioether groups in the molecule, that is, episulfide resins are preferable, and epoxy compounds are more preferable. One type of thermosetting resin may be used alone, or two or more types may be used in combination.

The above-mentioned epoxy compound is a compound having an epoxy group, and any conventionally known compound can be used. Examples thereof include polyfunctional epoxy compounds having a plurality of epoxy groups in the molecule. It may be a hydrogenated epoxy compound.

Examples of the polyfunctional epoxy compound include epoxidized vegetable oil; bisphenol A type epoxy resin; hydroquinone type epoxy resin; bisphenol type epoxy resin; thioether type epoxy resin; brominated epoxy resin; novolac type epoxy resin; biphenol novolac type epoxy resin; bisphenol F. Type epoxy resin; hydrogenated bisphenol A type epoxy resin; glycidylamine type epoxy resin; hydrantin type epoxy resin; alicyclic epoxy resin; trihydroxyphenylmethane type epoxy resin; bixyleneol 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; Tetraglycidyl xylenoyl ethane resin; Naphthalene group-containing epoxy resin; Dicyclopentadiene skeleton Epoxy resin with glycidyl methacrylate copolymer; epoxy resin copolymerized with cyclohexyl maleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivative; CTBN-modified epoxy resin and the like, but are not limited thereto. .. These epoxy resins may be used alone or in combination of two or more. Among these, novolak type epoxy resin, bisphenol type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin, biphenol novolac type epoxy resin, naphthalene type epoxy resin or a mixture thereof is particularly preferable.

Examples of the polyfunctional oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, and 1,4-bis [(3-3-oxythylmethoxy) methyl] ether. Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-3) Oxetane) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and polyfunctional oxetane such as their oligomers or copolymers, as well as oxetane alcohol and novolak resin , Poly (p-hydroxystyrene), cardo-type bisphenols, calix arrayes, calix resorcinarenes, etherified products with a resin having a hydroxyl group such as silsesquioxane, and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate can also be mentioned.

Examples of the compound having a plurality of cyclic thioether groups in the molecule include bisphenol A type episulfide resin and the like. Further, using the same synthesis method, an episulfide resin in which the oxygen atom of the epoxy group of the novolak type epoxy resin is replaced with a sulfur atom can also be used.

Examples of amino resins such as melamine derivatives and benzoguanamine derivatives include methylol melamine compounds, methylol benzoguanamine compounds, methylol glycol uryl compounds and methylol urea compounds.

A polyisocyanate compound can be blended as the isocyanate compound. Examples of the polyisocyanate compound include 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate and Aromatic polyisocyanates such as 2,4-tolyrene isocyanate dimer; aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis (cyclohexylisocyanate) and isophorone diisocyanate; Alicyclic polyisocyanates such as bicycloheptanetriisocyanate; and adducts, burettes, and isocyanurates of the isocyanate compounds mentioned above can be mentioned.

As the blocked isocyanate compound, an addition reaction product of the isocyanate compound and the isocyanate blocking agent can be used. Examples of the isocyanate compound capable of reacting with the isocyanate blocking agent include the above-mentioned polyisocyanate compound and the like. Examples of isocyanate blocking agents include phenol-based blocking agents; lactam-based blocking agents; active methylene-based blocking agents; alcohol-based blocking agents; oxime-based blocking agents; mercaptan-based blocking agents; acid amide-based blocking agents; imide-based blocking agents; Amine-based blocking agents; imidazole-based blocking agents; imine-based blocking agents and the like can be mentioned.

The blending amount of the thermosetting resin is, for example, 1 to 50% by mass based on the total solid content of the composition.

(Curing accelerator)
The curable resin composition of the present invention can contain a curing accelerator. Examples of the curing accelerator include imidazole, 2-methylimidazole, 2-ethyl imidazole, 2-ethyl-4-methyl imidazole, 2-phenyl imidazole, 4-phenyl imidazole, 1-cyanoethyl-2-phenyl imidazole, 1-. Imidazole derivatives such as (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzyl Examples include amine compounds such as amines, 4-methyl-N, N-dimethylbenzylamine and 4-dimethylaminopyridine, hydrazine compounds such as adipic acid 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-isocyanuric acid adduct can also be used. As the curing accelerator, one type may be used alone, or two or more types may be used in combination.

The blending amount of the curing accelerator is, for example, 0.01 to 30% by mass in the total solid content of the composition.

(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 that it does not contain halogen from the viewpoint of reducing the environmental load and affecting the human body. As the colorant, one type may be used alone, or two or more types may be used in combination.

The blending amount of the colorant is, for example, 0.01 to 10% by mass based on the total solid content of the composition.

(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 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. One of these organic solvents may be used alone, or two or more thereof may be used in combination.

(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, antioxidants, antibacterial / antifungal agents, antifoaming agents, leveling. Agents, thickeners, adhesion imparting agents, thixoness imparting agents, photoinitiator aids, sensitizers, organic fillers, elastomers, thermoplastic resins, mold release agents, surface treatment agents, dispersants, dispersion aids, surfaces Examples include modifiers, stabilizers, and phosphors.

Further, the curable resin composition of the present invention may contain (A) an alkali-soluble resin or a solvent-soluble resin that is not a photocurable resin as long as the effects of the present invention are not impaired.

The curable resin composition of the present invention is not particularly limited, and may be, for example, a photocurable thermosetting resin composition or a non-thermosetting photocurable resin composition. Further, it may be an alkali-developed type or a solvent-developed type. That is, when the composition of the present invention is an alkali-developable type containing an alkali-soluble resin, a negative-type pattern cured film can be obtained by irradiation with active energy rays and an alkali developer, and when the composition does not contain the alkali-soluble resin. Can obtain a negative pattern cured film by irradiation with active energy rays and a developing solution composed of an organic solvent.

As the optional component contained in the curable resin composition of the present invention, a known and commonly used component may be selected according to the curability and application.

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.

The dry film of the present invention has a resin layer obtained by applying the curable resin composition of the present invention on a carrier film and drying it. 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 polyamideimide 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 applied to 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 stack 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.

As a method for producing a printed wiring board using the curable resin composition of the present invention, a conventionally known method may be used. Taking the case of an alkali-developed photocurable thermosetting resin composition as an example, 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 the substrate is used. After applying by a method such as a dip coating method, a flow coating method, a roll coating method, a bar coater method, a screen printing method, a curtain coating method, etc., the organic solvent contained in the composition is applied at a temperature of 60 to 100 ° C. A tack-free resin layer is formed by volatile drying (temporary drying). Further, in the case of a dry film, a resin layer is formed on the substrate by sticking the resin layer on the substrate with a laminator or the like so as to be in contact with the substrate and then peeling off the carrier film.

The above-mentioned substrates include printed wiring boards and flexible printed wiring boards whose circuits are formed in advance with copper or the like, as well as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, and glass cloth / paper epoxy. It is made of materials such as copper-clad laminates for high-frequency circuits using synthetic fiber epoxy, fluororesin / polyethylene / polyimideene ether, polyphenylene oxide / cyanate, etc., and all grades (FR-4, etc.) of copper-clad laminates. In addition, metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like can be mentioned. The circuit may be pretreated. For example, GliCAP manufactured by Shikoku Chemicals Corporation, New Organic AP (Adhesion promoter) manufactured by MEC, Nova Bond manufactured by Atotech Japan, etc. are used for pretreatment and solder. Adhesion to a cured film such as a resist may be improved, or pretreatment may be performed with a rust preventive.

Volatile drying performed after applying the curable resin composition of the present invention is carried out in a hot air circulation type drying oven, IR furnace, hot plate, convection oven, etc. (using a steam-based air heating type heat source in the dryer). 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.

As the exposure machine used for the above-mentioned active energy ray irradiation, if it is 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 the active energy ray in the range of 350 to 450 nm. Often, a projection exposure machine using a projection lens or a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser from CAD data from a computer) can also be used as a maskless exposure that does not contact the substrate. .. 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 exposure amount for image formation varies depending on the film thickness and the like, but can be generally in the range of 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 an electronic component, particularly for forming a cured film on a printed wiring board, and more preferably for forming a permanent film. And more preferably used to form solder resists, interlayer insulating layers, coverslays, encapsulants. Further, it is suitable for forming a permanent coating (particularly solder resist) for a printed wiring board, for example, a package substrate, particularly FC-BGA, which requires a high degree of reliability. Further, the curable resin composition of the present invention can be suitably used for a printed wiring board having a wiring pattern even if the roughness of the circuit surface is small, for example, a printed wiring board for high frequency. For example, even if the surface roughness Ra is 0.05 μm or less, particularly 0.03 μm or less, it can be preferably used. It can also be suitably used when a cured film is formed on a low-polarity base material, for example, a base material containing an active ester. Further, it is suitably used for forming a cured film on a roughening-free wafer or a glass substrate.

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 photocurable resin]
(Photocurable Resin A-1)
A flask equipped with a cooling tube and a stirrer was charged with 456 parts of bisphenol A, 228 parts of water, and 649 parts of 37% formalin, kept at a temperature of 40 ° C. or lower, and added 228 parts of a 25% sodium hydroxide aqueous solution. The reaction was carried out at ° C. for 10 hours. After completion of the reaction, the mixture was cooled to 40 ° C. and neutralized to pH 4 with a 37.5% aqueous phosphoric acid solution while maintaining 40 ° C. or lower. After that, it was allowed to stand and the aqueous layer was separated. After separation, 300 parts of methyl isobutyl ketone was added to uniformly dissolve the mixture, followed by washing with 500 parts of distilled water three times, and the water, solvent and the like were removed under reduced pressure at a temperature of 50 ° C. or lower. The obtained polymethylol compound was dissolved in 550 parts of methanol to obtain 1230 parts of a methanol solution of the polymethylol compound.
When a part of the obtained methanol solution of the polymethylol compound was dried in a vacuum dryer at room temperature, the solid content was 55.2%.
In a flask equipped with a cooling tube and a stirrer, 500 parts of a methanol solution of the obtained polymethylol compound and 440 parts of 2,6-xylenol were charged and dissolved uniformly at 50 ° C. After uniformly dissolving, methanol was removed under reduced pressure at a temperature of 50 ° C. or lower. Then, 8 parts of oxalic acid was added, and the reaction was carried out at 100 ° C. for 10 hours. After completion of the reaction, the distillate was removed at 180 ° C. under a reduced pressure of 50 mmHg to obtain 550 parts of novolak resin A.
In an autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirrer, 130 parts of Novolak resin A, 2.6 parts of a 50% sodium hydroxide aqueous solution, and toluene / methyl isobutyl ketone (mass ratio = 2/1). 100 parts were charged, the inside of the system was replaced with toluene while stirring, then the temperature was raised by heating, and 60 parts of propylene oxide was gradually introduced at 150 ° C. and 8 kg / cm ² to react. The reaction was continued for about 4 hours until the gauge pressure reached 0.0 kg / cm ^2, and then cooled to room temperature. 3.3 parts of a 36% aqueous hydrochloric acid solution was added to and mixed with this reaction solution to neutralize sodium hydroxide. The neutralization reaction product was diluted with toluene, washed with water three times, and desolvated with an evaporator to have a hydroxyl value of 189 g / eq. A propylene oxide adduct of novolak resin A was obtained. This was an average addition of 1 mol of propylene oxide per equivalent of phenolic hydroxyl group.
189 parts of propylene oxide adduct of the obtained novolak resin A, 36 parts of acrylic acid, 3.0 parts of p-toluenesulfonic acid, 0.1 part of hydroquinone monomethyl ether and 140 parts of toluene were mixed with a stirrer, a thermometer and an air blowing tube. The mixture was charged into a reactor equipped with the above, stirred while blowing air, heated to 115 ° C., and the water produced by the reaction was distilled off as an azeotropic mixture with toluene to react for another 4 hours, and then to room temperature. Cooled. The obtained reaction solution was washed with water using a 5% NaCl aqueous solution, toluene was removed by distillation under reduced pressure, and then diethylene glycol monoethyl ether acetate was added to obtain an acrylate resin solution having a solid content of 67%.
Next, 322 parts of the obtained acrylate resin solution, 0.1 part of hydroquinone monomethyl ether, and 0.3 part of triphenylphosphine were charged into a four-necked flask equipped with a stirrer and a reflux condenser, and the mixture was charged at 110 ° C. To, 60 parts of tetrahydrophthalic anhydride was added, the mixture was reacted for 4 hours, cooled, and then taken out. The photosensitive carboxyl group-containing resin solution A-1 thus obtained had a solid content of 70% and a solid content acid value of 81 mgKOH / g. The values shown in Table 1 are parts by mass of the solid content that does not contain a solvent.

(Photocurable resin A-2)
81.5 parts of carbitol acetate was placed in a separable flask with a cooling tube as a reaction vessel, replaced with nitrogen, and then the temperature was raised to 80 ° C. On the other hand, 30 parts of N-phenylmaleimide and 120 parts of carbitol acetate were mixed in the dropping tank 1, 29 parts of styrene and 20 parts of 2-hydroxyethyl methacrylate were mixed in the dropping tank 2, and the dropping tank 3 21 parts of acrylic acid and 10.6 parts of hydrocarbon acetate are mixed, and the dropping tank 4 contains 70% of t-butylperoxypivalate as a polymerization initiator, Luperox 11 (trade name: manufactured by Alchema Yoshitomi Co., Ltd.). A mixture of 10 parts (hydrocarbon solution) and 21.2 parts of carbitol acetate was charged. While maintaining the reaction temperature at 80 ° C., the dropping was carried out from the dropping tanks 1, 2, 4 to 3 hours and from the dropping tank 3 for 2.5 hours. After the completion of the dropping, the reaction was continued at 80 ° C. for 30 minutes. Then, the reaction temperature was raised to 95 ° C., and the reaction was continued for 1.5 hours to obtain a polymer solution before the radical polymerizable double bond introduction reaction.
Next, 9.9 parts of glycidyl methacrylate, 7.4 parts of carbitol acetate as a reaction catalyst, 0.7 parts of triphenylphosphine as a reaction catalyst, and Antage W-400 (manufactured by Kawaguchi Chemical Industry Co., Ltd.) as a polymerization inhibitor in this polymer solution. ) Was added and reacted at 115 ° C. while bubbling a mixed gas of nitrogen and oxygen (oxygen concentration 7%) to obtain a photosensitive carboxyl group-containing radical polymerizable polymer solution A-2. .. This photosensitive carboxyl group-containing copolymer resin had a solid content of 32% and a solid content acid value of 120 mgKOH / g. The values shown in Table 1 are parts by mass of the solid content that does not contain a solvent.

(Photocurable resin A-3)
700 g of diethylene glycol monoethyl ether acetate and orthocresol novolac type epoxy resin [manufactured by DIC Corporation, EPICLON N-695, 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. Next, 4.3 g of triphenylphosphine was charged, heated to 110 ° C. for 2 hours, then 1.6 g of triphenylphosphine was further added, the temperature was raised to 120 ° C., and the reaction was carried out for another 12 hours. 562 g of aromatic hydrocarbon (Solbesso 150) and 684 g (4.5 mol) of tetrahydrophthalic anhydride were charged into the obtained reaction solution, and the reaction was carried out at 110 ° C. for 4 hours. Further, 142.0 g (1.0 mol) of glycidyl methacrylate was charged into the obtained reaction solution, and the reaction was carried out at 115 ° C. for 4 hours to obtain a carboxyl group-containing resin solution. The photosensitive carboxyl group-containing resin solution A-3 thus obtained had a solid content of 65% and an acid value of the solid content of 87 mgKOH / g. The values shown in Table 1 are parts by mass of the solid content that does not contain a solvent.

[Preparation of inorganic filler]
C-1:
Spherical silica (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm) 60 g, MEK (methyl ethyl ketone) 40 g as a solvent, and a silane coupling agent having a methoxy group (KBM-202SS manufactured by Shin-Etsu Chemical Co., Ltd .: D line (25) A silica solvent-dispersed product C-1 was obtained by uniformly dispersing 1.54) and 2 g of a refractive index at (° C.).

C-2:
Spherical silica (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm) 60 g, MEK (methyl ethyl ketone) 40 g as a solvent, a methoxy group, and a silane coupling agent having a fluorene skeleton having a cardo structure (manufactured by Osaka Gas Chemical Co., Ltd.) A silica solvent-dispersed product C-2 was obtained by uniformly dispersing 2 g of a refractive index of 1.56) in SC-001: D line (25 ° C.).

C-3:
Spherical silica (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm) 60 g, MEK (methyl ethyl ketone) 40 g as a solvent, a methoxy group, and a silane coupling agent having a fluorene skeleton having a cardo structure (manufactured by Osaka Gas Chemical Co., Ltd.) SC-003: Refractive index 1.53) 2 g on D line (25 ° C.) was uniformly dispersed to obtain a silica solvent-dispersed product C-3.

C-4:
Spherical silica (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm) 60 g, MEK (methyl ethyl ketone) 40 g as a solvent, methoxy group, and a silane coupling agent having a fluorene skeleton having a cardo structure (manufactured by Osaka Gas Chemical Co., Ltd.) SC-001: Refractive index at D line (25 ° C.) 1.56) After 2 g is uniformly dispersed, a silane coupling agent further having a methoxy group and a methacryl group (KBM-503: D line (manufactured by Shinetsu Chemical Industry Co., Ltd.) The refractive index of 1.43) at 25 ° C.) was uniformly dispersed with 1 g to obtain a silica solvent-dispersed product C-4.

C-5:
Spherical silica (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm) 60 g, MEK (methyl ethyl ketone) 40 g as a solvent, a silane coupling agent having a fluorene skeleton having a methoxy group and a cardo structure (manufactured by Osaka Gas Chemical Co., Ltd.) SC-001: Refractive index at D line (25 ° C.) 1.56) After 2 g is uniformly dispersed, a silane coupling agent further having a methoxy group and an amino group (KBM-573: D line (manufactured by Shinetsu Chemical Industry Co., Ltd.) The refractive index of 1.43) at 25 ° C.) was uniformly dispersed with 1 g to obtain a silica solvent-dispersed product C-5.

R-1:
Spherical silica (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm) 60 g, MEK (methyl ethyl ketone) 40 g as a solvent, and a silane coupling agent having a methoxy group and a methacrylic group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.): A silica solvent-dispersed product R-1 was obtained by uniformly dispersing 2 g of a refractive index of 1.43) on the D line (25 ° C.).

R-2:
60 g of spherical silica (SFP-20M manufactured by Denka, average particle size: 400 nm, refractive index at D line (25 ° C.) 1.42) and 40 g of MEK (methyl ethyl ketone) as a solvent are uniformly dispersed, and the silica solvent-dispersed product R I got -2.

R-3:
60 g of barium sulfate (B-30NC (unsurface treated product) manufactured by Sakai Chemical Industry Co., Ltd., average particle size: 300 nm, refractive index at D line (25 ° C.) 1.65) and 40 g of MEK (methyl ethyl ketone) as a solvent are uniformly dispersed. The barium solvent-dispersed product R-3 was obtained.
These were blended so as to have the solid content of the numerical values of Examples and Comparative Examples.

<Refractive index measurement method>
The refractive index of the photocurable resin, the organic alkoxysilane and the inorganic filler adjusted above was measured by applying each sample on glass using a refractive index meter ER-7MW manufactured by ERMA, and drying the sample at 25 ° C. Measured under conditions.

[Examples 1 to 6, Comparative Examples 1 and 2]
The above resin solution (varnish) is mixed with the various components shown in the table at the indicated ratios (parts by mass), premixed with a stirrer, and then kneaded with a three-roll mill to prepare a curable resin composition. did.

<Making dry film>
300 g of methyl ethyl ketone was added to the curable resin composition prepared as described above to dilute it, and the mixture was stirred with a stirrer for 15 minutes to obtain a coating liquid. The coating liquid was applied onto a polyethylene terephthalate film having a thickness of 38 μm (carrier film: Embret PTH-25 manufactured by Unitika Ltd.) and dried at a temperature of 80 ° C. for 15 minutes to form a resin layer having a thickness of 20 μm. .. Next, a biaxially stretched polypropylene film (cover film: OPP-FOA manufactured by Futamura Co., Ltd.) was laminated on the resin layer to prepare a dry film.

<Resolution>
Vacuum pressure 3 hPa, vacuum in the first chamber at 100 ° C. using a vacuum laminator (CVP-600: manufactured by Nikko Material Co., Ltd.) on the copper of the copper-clad laminate in which the dry films of each example and the comparative example were acid-treated. After laminating under the condition of a time of 30 seconds, pressing was performed under the conditions of a press pressure of 0.5 MPa and a press time of 30 seconds to obtain an evaluation substrate. Then, after exposing an aperture pattern of φ30 μm with a DI exposure machine (light source: mercury short arc lamp) with an exposure amount of 10 steps with a step tablet (41 steps), the PET film is peeled off and developed (1 mass% Na _2). CO ₃ , 30 ° C., 0.2 MPa) was carried out in 60 seconds to form a pattern of the resin layer. Subsequently, the resin layer is irradiated with an exposure amount of 1 J / cm ^{2 in} a UV conveyor furnace equipped with a high-pressure mercury lamp, and then heated at 160 ° C. for 60 minutes to completely cure the resin layer to have an evaluation substrate having a pattern cured film. Was prepared, and the length of the photosensitive cured coating film was measured.
⊚: Top 30 μm, Bottom opening 95-100%
〇: Top 30 μm, Bottom opening 85% or more, less than 95% Δ: Both Top and Bottom have an opening accuracy of 80 to 90% ×: Halation and undercut occur

<Implantability and BHAST resistance>
After acid-treating the substrate on which the circuit pattern of conductor thickness 10 μm L / S = 8 μm / 8 μm is formed, the dry film is laminated, exposed, developed, and cured in the same manner as in the above <resolution> evaluation, and the embedding property is confirmed. After that, BHAST was performed at 130 ° C., 85%, and 3 V to evaluate the insulation reliability.
⊚: Embedded without voids, achieving insulation reliability of BHAST 300 hrs or more 〇: Embedding without voids, achieving insulation reliability of BHAST 200 or more and less than 300 hrs Δ: Voids of about 1 to 2 μm were confirmed, and dielectric strength was less than 200 hrs ×: 5 μm The above omissions were confirmed.

<High temperature standing test>
Vacuum in the first chamber at 100 ° C. using a vacuum laminator (CVP-600: manufactured by Nikko Material Co., Ltd.) on the copper of the copper-clad laminate in which the dry films of each example and the comparative example were treated with CZ8101 manufactured by MEC. After laminating under the conditions of a pressure of 3 hPa and a vacuum time of 30 seconds, pressing was performed under the conditions of a press pressure of 0.5 MPa and a press time of 30 seconds to obtain an evaluation substrate. Then, after exposure with a DI exposure machine so as to form a punching pattern of φ200 μm with an exposure amount of 10 steps with a step tablet (41 steps), the PET film is peeled off and developed (1 mass% Na ₂ CO ₃ , 30). ℃, 0.2 MPa) was carried out in 60 seconds to form a pattern of the resin layer. Subsequently, the resin layer is irradiated with an exposure amount of 1 J / cm ^{2 in} a UV conveyor furnace equipped with a high-pressure mercury lamp, and then heated at 160 ° C. for 60 minutes to completely cure the resin layer to have an evaluation substrate having a pattern cured film. Was produced.
The substrate was placed in a constant temperature bath having an oxygen atmosphere at 175 ° C., and the time during which peeling with the cellophane tape peel did not occur was confirmed.
⊚: No peeling of 2000 hrs or more 〇: Some peeling occurs at 1500 hrs or more and less than 2000 hrs Δ: Peeling occurs at 1000 hrs or more and less than 1500 hrs ×: Peeling occurs within 1000 hrs

<CTE>
A cured film was formed on the low profile copper foil under the same conditions as the above <high temperature standing test>. The obtained cured film was peeled off from the copper foil, a sample was cut out so that a measurement size (3 mm × 10 mm size) could be obtained, and CTE was measured with TMA6100 manufactured by Hitachi High-Tech. The measurement conditions were that the test load was 5 g and the sample was heated above room temperature at a rate of temperature rise of 10 ° C./min twice, and a linear expansion coefficient (CTE (α2)) of Tg or less was obtained in the second time. It can be seen that the smaller the CTE, the better the thermal stability.
⊚: 30 ppm or less 〇: 30 ppm or more, 40 ppm or less Δ: 40 ppm or more, 50 ppm or less ×: 50 ppm or less

<Cold heat resistance evaluation>
Each dry film was laminated on a BT substrate on which a 2 mm copper line pattern was formed in the same manner as in the above <high temperature standing test> and <resolution> evaluation, and was heat-cured by exposure, development, and UV. However, the pattern at the time of exposure was changed so as to be a 3 mm square cured film pattern, and an evaluation substrate in which a 3 mm square cured film pattern was formed on a copper line was produced. This substrate was placed in a thermal cycle machine in which a temperature cycle was performed between −50 ° C. and 150 ° C., and TCT (Thermal Cycle Test) was performed. Then, cracks were confirmed when evaluated up to 1000 cycles.
⊚: No cracks occurred up to 1000 cycles.
〇: A crack occurred in 500 to 750 cycles.
Δ: Cracks occurred at 250 cycles or more and less than 500 cycles.
X: Cracks occurred below 250 cycles.

* The difference in the refractive index of the (A) photocurable resin and the organic alkoxysilane in the D line (25 ° C.) in Example 2 is the difference from the * 2 photocurable resin.

* 1: Solution A-1 of the photocurable resin synthesized above (refractive index 1.56 at D line (25 ° C))
* 2: Solution A-2 of the photocurable resin synthesized above (refractive index 1.55 at D line (25 ° C))
* 3: Solution A-3 of the photocurable resin synthesized above (refractive index 1.56 at D line (25 ° C))
* 4: Omnirad TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) manufactured by IGM Resins.
* 5: Omnirad 907 manufactured by IGM Resins (2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one)
* 6: DPHA manufactured by Nippon Kayaku Co., Ltd. (dipentaerythritol hexaacrylate, refractive index 1.48 at D line (25 ° C))
* 7: Mitsubishi Chemical's jER828 (bisphenol A type epoxy resin)
* 8: NC-6000 manufactured by Nippon Kayaku Co., Ltd. (2- (4-hydroxyphenyl) -2- [4- [1,1-bis (4-hydroxyphenyl) ethyl] phenyl] propane glycidyl ether compound)
* 9: NC-3000H (biphenol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.
* 10: Phthalocyanine blue * 11: Dicyandiamide * 12: Melamine C-1: Silica coated with a silane coupling agent having a methoxy group (refractive index at D line (25 ° C.) 1.54) adjusted above. Solvent dispersion product C-1
C-2: A solvent-dispersed product of silica coated with a silane coupling agent having a fluorene skeleton having a methoxy group and a cardo structure (refractive index at D line (25 ° C.) of 1.56) prepared above. 2
C-3: Solvent-dispersed product of silica coated with a silane coupling agent having a fluorene skeleton having a methoxy group and a cardo structure (refractive index at D line (25 ° C.) of 1.53) prepared above. 3
C-4: A silane coupling agent having a methoxy group and a fluorene skeleton having a cardo structure (refractive index at D line (25 ° C.) of 1.56) prepared above, and a silane cup having a methoxy group and a methacryl group. Silane solvent-dispersed product C-4 coated with a ring agent (refractive index at D-ray (25 ° C.) 1.43)
C-5: A silane coupling agent having a methoxy group and a fluorene skeleton having a cardo structure (refractive index at D line (25 ° C.) of 1.56) prepared above, and a silane cup having a methoxy group and an amino group. Solvent-dispersed product C-5 of silica coated with a ring agent (refractive index at D line (25 ° C.) 1.43)
R-1: Solvent-dispersed product of silica coated with a silane coupling agent having a methoxy group and a methacrylic group (refractive index 1.43 at D line (25 ° C.)) adjusted above.
R-2: Solvent-dispersed product of silica (refractive index 1.42 at D line (25 ° C)) adjusted above R-2
R-3: Solvent-dispersed product of barium (refractive index 1.65 at D line (25 ° C.)) adjusted above R-3

From the results shown in the above table, it can be seen that the curable resin compositions of Examples 1 to 6 of the present invention can be obtained as a cured product having excellent resolution and embedding property of a high-density wiring pattern.

Claims

(A) Photocurable resin,
(B) Photopolymerization initiator and
(C) A curable resin composition containing silica.
The refractive index of the (A) photocurable resin in the D line measured at 25 ° C. is 1.50 to 1.65.
A curable resin composition, wherein the silica (C) is coated with an organic alkoxysilane having a refractive index of 1.50 to 1.65 in the D line measured at 25 ° C.
The curable resin composition according to claim 1, wherein the organic alkoxysilane has a cardo structure.
Claim 1 is characterized in that the silica (C) is coated with at least two kinds of the organic alkoxysilanes, or is coated with an organic alkoxysilane other than the organic alkoxysilane and the organic alkoxysilane. Alternatively, the curable resin composition according to 2.
A dry film characterized by having a resin layer obtained by applying the curable resin composition according to any one of claims 1 to 3 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 3 or the resin layer of the dry film according to claim 4.
An electronic component having the cured product according to claim 5.