阅读说明：本技术 固化性树脂组合物、干膜、固化物和电子部件 (Curable resin composition, dry film, cured product, and electronic component ) 是由 植田千穗 冈田和也 工藤知哉 岛田沙和子 种将太郎 于 2019-12-16 设计创作，主要内容包括：提供：可以得到分辨率和高密度布线图案的埋入性优异的固化物的固化性树脂组合物、具有由该组合物得到的树脂层的干膜、该组合物或该干膜的树脂层的固化物、和具有该固化物的电子部件。为固化性树脂组合物等,所述固化性树脂组合物的特征在于,包含：(A)光固化性树脂、(B)光聚合引发剂、和(C)二氧化硅,前述(A)光固化性树脂的在25℃下测得的D射线下的折射率为1.50～1.65,前述(C)二氧化硅被在25℃下测得的D射线下的折射率为1.50～1.65的有机烷氧基硅烷所覆盖。(Providing: a curable resin composition which can give a cured product excellent in resolution and embeddability in a high-density wiring pattern, 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 comprising: (A) a photocurable resin, (B) a photopolymerization initiator, and (C) silica, wherein the refractive index of the photocurable resin (A) under D rays measured at 25 ℃ is 1.50-1.65, and the silica (C) is covered with an organoalkoxysilane having a refractive index of the silica (C) under D rays measured at 25 ℃ of 1.50-1.65.)

1. A curable resin composition characterized by comprising:

(A) a photocurable resin,

(B) A photopolymerization initiator, and

(C) the amount of silicon dioxide,

the refractive index of the photocurable resin (A) under a D ray measured at 25 ℃ is 1.50-1.65,

the silica (C) is covered with an organoalkoxysilane having a refractive index of 1.50 to 1.65 measured at 25 ℃ under D-ray.

2. The curable resin composition according to claim 1, wherein the organoalkoxysilane has a Cardo structure.

3. The curable resin composition according to claim 1 or 2, wherein the (C) silica is covered with at least 2 kinds of the organoalkoxysilanes, or the organoalkoxysilane other than the organoalkoxysilane and the organoalkoxysilane.

4. A dry film comprising 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 applied film.

5. 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.

6. An electronic component comprising the cured product according to claim 5.

Technical Field

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

Background

In a curable resin composition used for a solder resist of a semiconductor package, etc., there is an increasing demand for resolution accuracy with a Fine Pitch (Fine Pitch). On the other hand, since it is necessary to have resistance to thermal stress, an operation of controlling the thermal expansion coefficient by adding a resin or an inorganic material having high heat resistance is performed. Therefore, the inorganic materials used have been dependent on the use of silica not only for physical properties such as lowering the CTE and crack resistance but also for ease of cost, specific gravity, and the like.

For example, patent document 1 discloses a photosensitive resin composition which combines 2 kinds of inorganic fillers having a specific refractive index and organic fillers having a specific particle diameter and provides a low linear expansion coefficient together with a high resolution.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 6210060

Disclosure of Invention

Problems to be solved by the invention

However, even the photosensitive resin composition described in patent document 1 can obtain a sufficiently high resolution in response to a demand for high resolution accuracy accompanied by fine pitch.

Further, there is a problem that the viscosity of the composition increases due to the compounding of silica, the embedding accuracy of a high-density wiring pattern is poor, and the insulation reliability is lowered.

Accordingly, an object of the present invention is to provide: a curable resin composition which can give a cured product excellent in resolution and embeddability in a high-density wiring pattern, 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.

Means for solving the problems

The present inventors have made intensive studies with a view to achieving the above object, focusing on the surface treatment of silica. As a result, the present inventors have found that: the present inventors have completed the present invention by solving the above problems by compounding silica coated with an organoalkoxysilane having a refractive index of 1.50 to 1.65 at a D-ray (25 ℃) to a photocurable resin having a refractive index of 1.50 to 1.65 at a D-ray (25 ℃).

That is, the curable resin composition of the present invention is characterized by comprising: (A) a photocurable resin, (B) a photopolymerization initiator, and (C) silica, wherein the refractive index of the photocurable resin (A) under D rays measured at 25 ℃ is 1.50-1.65, and the silica (C) is covered with an organoalkoxysilane having a refractive index of the silica (C) under D rays measured at 25 ℃ of 1.50-1.65.

In the curable resin composition of the present invention, the organoalkoxysilane preferably has a Cardo structure.

In the curable resin composition of the present invention, the silica (C) is preferably covered with at least 2 kinds of the organoalkoxysilanes, or with the organoalkoxysilane other than the organoalkoxysilane and the organoalkoxysilane.

The dry film of the present invention is characterized by comprising a resin layer obtained by applying the curable resin composition to a film and drying the applied resin layer.

The cured product of the present invention is 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.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided: a curable resin composition which can give a cured product excellent in resolution and embeddability in a high-density wiring pattern, 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.

Detailed Description

The curable resin composition of the present invention is characterized by comprising: (A) a photocurable resin, (B) a photopolymerization initiator, and (C) silica, wherein the refractive index of the photocurable resin (A) under D rays measured at 25 ℃ is 1.50-1.65, and the silica (C) is covered with an organoalkoxysilane having a refractive index of the silica (C) under D rays measured at 25 ℃ of 1.50-1.65.

Conventionally, the refractive index of silica at D-ray (25 ℃) is 1.42, and the higher the filling, the more the scattered light at the interface increases, and the smaller-diameter aperture is hardly obtained.

On the other hand, the present invention combines the use of a photocurable resin having a refractive index of 1.50 to 1.65 under D-ray (25 ℃) with silica coated with an organoalkoxysilane having a refractive index of 1.50 to 1.65 under D-ray (25 ℃), thereby providing excellent resolution and embeddability of high-density wiring patterns.

That is, in the present invention, since the refractive index difference between the (a) photocurable resin having the refractive index and the silica surface covered with the specific organoalkoxysilane having the refractive index is relatively close, scattering of the active energy ray (rayleigh scattering and Mie scattering) can be prevented. This theoretically maximizes the transmittance of the active energy ray, and in the present invention, a good deep-curing property can be obtained. Thus, even when silica is highly filled, a cured product having excellent resolution can be obtained.

In the present invention, the difference between the refractive index of the photocurable resin (a) and the refractive index of the organoalkoxysilane covering the silica (B) is preferably 0.10 or less, more preferably 0.08 or less, still more preferably 0.06 or less, and particularly preferably 0.03 or less. Here, when a plurality of (a) photocurable resins and (C) silica-coated organoalkoxysilanes are present, the difference between the refractive index of any (a) photocurable resin and the refractive index of (B) silica-coated organoalkoxysilane may be 0.10 or less. When the number of the (a) photocurable resins is plural, the difference between the refractive index of the (a) photocurable resin, which is contained the most in the (a) photocurable resins, and the refractive index of the (C) silica-coated organoalkoxysilane, is preferably 0.10 or less in terms of mass%.

In the present invention, the organoalkoxysilane preferably has a Cardo structure such as a fluorene skeleton. By blending silica coated with organoalkoxysilane having a Cardo structure, a cured product having more excellent heat resistance can be obtained, and the cured product has excellent adhesion to a non-roughened substrate or a silicon substrate (i.e., a substrate having a small anchoring effect).

In the present invention, by using a photocurable resin (a) which is a photocurable resin and is a starting material of a phenol resin described later, a photocurable copolymer resin having a maleimide structure, and (C) silica coated with a specific organoalkoxysilane, not only improvement in resolution and further improvement in fluidity but also improvement in heat resistance and thermal stability can be confirmed.

The curable resin composition of the present invention is exposed to ultraviolet light (about 400nm), but the refractive index is controlled by the refractive index under D-rays, which is widely used. The curable resin composition of the present invention can obtain excellent resolution by using a combination of (a) a photocurable resin having a refractive index of 1.50 to 1.65 under D-ray and (C) silica coated with an organoalkoxysilane having a refractive index of 1.50 to 1.65 under D-ray, and thus it is understood that the object of the present invention can be sufficiently achieved by a combination in which the refractive index under D-ray is adjusted.

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

[ (A) Photocurable resin ]

(A) The photocurable resin has a refractive index of 1.50 to 1.65 under D-ray (25 ℃), and a compound having 1 or more ethylenically unsaturated groups in the molecule is preferably used. As the compound having an ethylenically unsaturated group, any 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 as a photosensitive monomer, a photopolymerizable vinyl monomer, or the like may be used, and a radical polymerizable monomer or a cation polymerizable monomer may be used. Examples of the ethylenically unsaturated group include a vinyl group and a (meth) acryloyl group. In the present specification, (meth) acryloyl is a term generically referring to acryloyl, methacryloyl and mixtures thereof, and the same applies to other similar expressions.

When the composition of the present invention is an alkali-developable composition, the photocurable resin (a) is preferably an alkali-soluble resin. (A) When the photocurable resin is an alkali-soluble resin, a cured product having particularly excellent resolution can be obtained. As the alkali-soluble resin, any resin having an alkali-soluble group, for example, 1 of phenolic hydroxyl group, mercapto group, and carboxyl group, may be used. Examples of the alkali-soluble resin include: a compound having 2 or more phenolic hydroxyl groups, a carboxyl group-containing resin, a compound having a phenolic hydroxyl group and a carboxyl group, a compound having 2 or more mercapto groups, and among these, a carboxyl group-containing resin is preferable because of its excellent developability. 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. (A) The photocurable resin may be used alone in 1 kind, or in combination with 2 or more kinds.

Specific examples of the photocurable resin (a) include the following compounds (both oligomers and polymers), but are not limited thereto.

(1) A carboxyl group-containing photosensitive resin having a copolymerized structure, which is obtained by adding a compound having 1 epoxy group and 1 or more (meth) acryloyl groups in the molecule, such as glycidyl (meth) acrylate or α -methylglycidyl (meth) acrylate, to 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.

(2) A carboxyl group-containing photosensitive resin having a urethane structure obtained by reacting a diisocyanate such as an aromatic diisocyanate with a carboxyl group-containing diol compound, with a diol compound, and with a compound having 1 isocyanate group and 1 or more (meth) acryloyl groups in the molecule.

(3-1) a carboxyl group-containing photosensitive resin having a urethane structure obtained by addition polymerization of a diisocyanate, a (meth) acrylate ester of a 2-functional epoxy resin or a modified product of a partial anhydride thereof, a carboxyl group-containing diol compound, and a diol compound.

(3-2) a carboxyl group-containing photosensitive resin having a urethane structure obtained by further adding a compound having 1 epoxy group and 1 or more (meth) acryloyl groups in the molecule to the carboxyl group-containing photosensitive resin of (3-1).

(3-3) a carboxyl group-containing photosensitive resin having a urethane structure obtained by reacting a diisocyanate, a (meth) acrylate of a 2-functional epoxy resin or a partial acid anhydride-modified product thereof, a carboxyl group-containing diol compound, a diol compound, and a compound having 1 hydroxyl group and 1 or more (meth) acryloyl groups in the molecule.

(3-4) a carboxyl group-containing photosensitive resin having a urethane structure obtained by reacting a diisocyanate, a (meth) acrylate of a 2-functional epoxy resin or a partial acid anhydride-modified product thereof, a carboxyl group-containing diol compound, a diol compound, and a compound having 1 isocyanate group and 1 or more (meth) acryloyl groups in the molecule.

(4) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy resin with an unsaturated monocarboxylic acid such as (meth) acrylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride or hexahydrophthalic anhydride to a hydroxyl group present in a side chain.

(5) And a carboxyl group-containing photosensitive resin obtained by further epoxidizing the hydroxyl group of the 2-functional epoxy resin with epichlorohydrin to obtain a polyfunctional epoxy resin and reacting the polyfunctional epoxy resin with an unsaturated group-containing monocarboxylic acid to add a dibasic acid anhydride to the resulting hydroxyl group.

(6) The carboxyl group-containing photosensitive resin is obtained by reacting an epoxy compound having a plurality of epoxy groups in 1 molecule, a compound having at least 1 alcoholic hydroxyl group and 1 phenolic hydroxyl group in 1 molecule such as p-hydroxyphenylethanol, and an unsaturated monocarboxylic acid, and reacting the alcoholic hydroxyl group of the obtained reaction product with a polybasic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and adipic anhydride.

(7) A carboxyl group-containing photosensitive resin obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in 1 molecule with an alkylene oxide such as ethylene oxide or propylene oxide with an unsaturated group-containing monocarboxylic acid and reacting the obtained reaction product with a polybasic acid anhydride.

(8) A carboxyl group-containing photosensitive resin obtained by reacting a compound having a plurality of phenolic hydroxyl groups in 1 molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate to obtain a reaction product, reacting the reaction product with an unsaturated group-containing monocarboxylic acid, and reacting the obtained reaction product with a polybasic acid anhydride.

(9) A carboxyl group-containing photosensitive resin having a copolymerized structure, which is obtained by adding a compound having 1 epoxy group and 1 or more (meth) acryloyl groups in a molecule, such as glycidyl (meth) acrylate, alpha-methylglycidyl (meth) acrylate, epoxycyclohexylmethyl (meth) acrylate, to a carboxyl group-containing copolymerized resin obtained by using as monomers a maleimide or maleimide derivative such as N-phenylmaleimide or N-benzylmaleimide, an unsaturated group-containing compound having a hydroxyl group such as (meth) acrylic acid, an unsaturated group-containing compound having an aromatic ring such as hydroxyalkyl (meth) acrylate, or an unsaturated group-containing compound having an aromatic ring such as styrene, alpha-methylstyrene, alpha-chlorostyrene, or vinyltoluene.

(10) A carboxyl group-containing photosensitive resin obtained by adding a compound having 1 epoxy group and 1 or more (meth) acryloyl groups in the molecule, such as glycidyl (meth) acrylate,. alpha. -methylglycidyl (meth) acrylate, epoxycyclohexylmethyl (meth) acrylate, to the carboxyl group-containing photosensitive resin of (2) to (8).

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

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

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

(A) The refractive index of the photocurable resin at D-ray (25 ℃) is preferably 1.52 or more, more preferably 1.54 or more.

(A) The amount of the photocurable resin is, for example, 10 to 50% by mass based on 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 under D-ray (25 ℃). For example, the amount of the photocurable compound having a refractive index of less than 1.50 may be less than 50% by mass based on the total amount of the photocurable compound having a refractive index of less than 1.50 and the photocurable resin having a refractive index of 1.50 to 1.65. 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; alkoxyalkylene glycol mono (meth) acrylates such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate; alkylene polyol poly (meth) acrylates such as ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like; polyoxyalkylene glycol poly (meth) acrylates such as diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane tri (meth) acrylate; poly (meth) acrylates such as hydroxypivalyl hydroxypivalate di (meth) acrylate, and the like.

[ (B) photopolymerization initiator ]

As the photopolymerization initiator (B), any photopolymerization initiator known as a photopolymerization initiator or photo radical 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, bis- (2, 6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -1-naphthylphosphine oxide, bisacylphosphine oxides such as bis- (2, 6-dimethoxybenzoyl) phenylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2,4, 4-trimethylpentylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2, 5-dimethylphenylphosphine oxide, and bis- (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide; monoacyl phosphine oxides such as 2, 6-dimethoxybenzoyldiphenylphosphine oxide, 2, 6-dichlorobenzoyldiphenylphosphine oxide, methyl 2,4, 6-trimethylbenzoylphenylphosphinate, 2-methylbenzoyldiphenylphosphine oxide, isopropyl pivaloylphenylphosphine oxide and 2,4, 6-trimethylbenzoyldiphenylphosphine oxide; hydroxyacetophenones such as 1-hydroxy-cyclohexylphenyl ketone, 1- [4- (2-hydroxyethoxy) -phenyl ] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl ] phenyl } -2-methyl-propan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoins such as benzoin, dibenzoyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; benzoin alkyl ethers; benzophenones such as benzophenone, p-methylbenzophenone, michelson, methylbenzophenone, 4 '-dichlorobenzophenone, 4' -bisdiethylaminobenzophenone and the like; acetophenones such as acetophenone, 2-dimethoxy-2-phenylacetophenone, 2-diethoxy-2-phenylacetophenone, 1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 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-morpholino) phenyl ] -1-butanone, and N, N-dimethylaminoacetophenone; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-chlorothioxanthone and 2, 4-diisopropylthioxanthone; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzil dimethyl ketal; benzoic acid esters such as ethyl-4-dimethyl urethane benzoate, 2- (dimethylamino) ethyl benzoate, and ethyl p-dimethylbenzoate; oxime esters such as {1- [4- (phenylthio) -2- (O-benzoyloxime) ] }1, 2-octanedione, 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -1- (O-acetyloxime) ethanone, and the like; titanium such as bis (. eta.5-2, 4-cyclopentadien-1-yl) -bis (2, 6-difluoro-3- (1H-pyrrol-1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis [2, 6-difluoro-3- (2- (1-pyrrol-1-yl) ethyl) phenyl ] titanium, etc.; phenyl-2-nitrofluorene disulfide, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide, and the like. The photopolymerization initiator may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

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

[ (C) silica ]

In the present invention, the silica (C) is covered with an organoalkoxysilane having a refractive index of 1.50 to 1.65 under D-ray (25 ℃). Examples of the silica include fused silica, spherical silica, amorphous silica, crystalline silica, and sol silica, and spherical silica is preferable.

The organoalkoxysilane having a refractive index of 1.50 to 1.65 under D-ray (25 ℃) is not particularly limited, and any known and commonly used organoalkoxysilane may be used. Examples thereof include (hereinafter, refractive index in measurement of refractive index D-ray (25 ℃ C., also referred to as sodium D-ray)), KBM-202SS (Dimethoxydiphenylsilane: refractive index 1.54), X-12-1156 (methoxy-and mercapto-containing organosilane: refractive index 1.52), X-12-1154 (methoxy-and mercapto-containing organosilane: refractive index 1.51), KR-511 (methoxy-and vinyl-containing siloxane: refractive index 1.51), X-12-1159L (methoxy-and isocyanate-containing organosilane: refractive index 1.50), KBM-573 (amino-containing N-phenyl-3-aminopropyltrimethoxysilane: refractive index 1.50), KBM-1403 (styryltrimethoxysilane: refractive index 1.50), Osaka Chemicals Co., Ltd., ltd., SC-001 (containing fluorenylsilane: refractive index: 1.56), SC-003 (containing fluorenylsilane: refractive index: 1.53), and the like. Among them, alkoxysilanes having an aromatic ring are preferable, and organoalkoxysilanes having a Cardo structure are particularly preferable. As described above, from the viewpoint of heat resistance, organoalkoxysilanes having a fluorene skeleton such as SC-001 and SC-003 are preferable, and organoalkoxysilanes having a fluorene skeleton with a Cardo structure are more preferable. The alkoxy group of the organoalkoxysilane is, for example, an alkoxy group having 1 to 5 carbon atoms. The organoalkoxysilane may be combined with 1 or 2 or more species depending on the refractive index of the photocurable resin (a).

Examples of the organoalkoxysilane having a fluorene skeleton having a Cardo structure include organoalkoxysilanes represented by the following formulae (1-1) and (1-2).

(wherein n and m each independently represent an integer of 1 to 6.)

Examples of commercially available organoalkoxysilanes of formula (1-1) include OGSOL SC-001 available from Osaka Gas Chemicals Co., Ltd. Further, examples of commercially available organoalkoxysilanes represented by the above formula (1-2) include OGSOL SC-003 manufactured by Osaka Gas Chemicals Co., Ltd.

The organoalkoxysilane may have a curable reactive group. The curable reactive group is not particularly limited as long as it is a group that undergoes a curing reaction with a component (for example, a photocurable resin or a thermosetting resin) blended in the curable resin composition, and may be a photocurable reactive group or a thermosetting reactive group.

The coating method is not particularly limited, and may be carried out by a known and commonly used method such as a method of treating silica with the organoalkoxysilane as the silane coupling agent.

The coating with the organoalkoxysilane having a refractive index of 1.50 to 1.65 based on D-ray (25 ℃) is, for example, 1 to 50 parts by mass with respect to 100 parts by mass of silica.

(C) The silica is preferably covered with at least 2 kinds of the organoalkoxysilanes, or with the organoalkoxysilane other than the organoalkoxysilane and the organoalkoxysilane. By blending the silica thus coated, a cured product having a low CTE and excellent cold and heat resistance can be obtained. This covering treatment may be performed before, after, or simultaneously with the aforementioned covering treatment with the organoalkoxysilane.

The organoalkoxysilane having a refractive index of 1.50 to 1.65 at D-ray (25 ℃) may or may not have a curable reactive group. When the organoalkoxysilane having a refractive index of 1.50 to 1.65 at D-ray (25 ℃) does not have a curable reactive group, it is preferable to use the organoalkoxysilane having a curable reactive group in combination. Thus, the heat resistance, thermal stability and crack resistance during cold and hot cycles are improved.

Examples of the organic silane other than the organoalkoxysilane include methacrylic silanes such as KBM-502 (refractive index: 1.43), KBM-503 (refractive index: 1.43), KBE-502 (refractive index: 1.43), KBE-503 (refractive index: 1.43), KBM-5803 (refractive index: 1.44) and KR-503 (refractive index: 1.45), and silanes having a refractive index of less than 1.50 such as 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) and KBM-1003 (refractive index: 1.39). The organic silane other than the organoalkoxysilane is preferably a silane having a reactive group with the component (a). Among them, methacrylic silane is preferable from the viewpoint of physical properties such as tensile strength. Further, epoxy silane such as KBM-403 (refractive index: 1.43) may be added to control the refractive index.

When the silica is further covered with an organic silane other than the organoalkoxysilane, the covering with the organic silane other than the organoalkoxysilane is 1 to 50 parts by mass per 100 parts by mass of the silica.

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

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

(C) The average particle diameter of the silica is, for example, 0.01 to 0.8. mu.m. In the present specification, the average particle size of (C) the silica is not only the particle size of the primary particles but also the average particle size (D50) including the particle size of the secondary particles (aggregates), and is the value of D50 measured by a laser diffraction method. An example of a measuring apparatus by the laser diffraction method is Microtrac MT3300EXII manufactured by MicrotracBEL.

The average particle diameter of the (C) silica may be adjusted, and for example, it is preferable to perform pre-dispersion in a bead mill or a jet mill. Further, it is preferable that the inorganic filler is blended in a slurry state, and the blending in a slurry state facilitates high dispersion, prevents aggregation, and facilitates handling.

(C) The silica may be used alone in 1 kind, or may be used in combination with 2 or more kinds. (C) The amount of silica may be, for example, 10 mass% or more, further 20 mass% or more, and further 30 mass% or more, based on the total solid content of the curable resin composition. The upper limit of the amount of silica is, for example, 80 mass% or less.

The curable resin composition of the present invention may contain (C) a known and commonly used inorganic filler other than silica, within a range not to impair the effects of the present invention. Examples of such inorganic fillers include: inorganic fillers other than silica, such as Nojenberg silica, aluminum hydroxide, glass powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, aluminum hydroxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, slag wool, aluminum silicate, calcium silicate, and zinc white, which are covered with an organoalkoxysilane having a refractive index of 1.50 to 1.65 under D-ray (25 ℃).

(thermosetting resin)

The curable resin composition of the present invention may contain a thermosetting resin. The thermosetting resin improves the heat resistance of the cured product and improves the adhesion to the substrate. As the thermosetting resin, a known and commonly used thermosetting resin such as an isocyanate compound, a blocked isocyanate compound, an amino resin, a benzoxazine resin, a carbodiimide resin, a cyclic carbonate compound, an epoxy compound, a polyfunctional oxetane compound, an episulfide resin, or the like can be used. Among these, epoxy compounds, polyfunctional oxetane compounds, and episulfide resins which are compounds having 2 or more sulfide groups in the molecule are preferable, and epoxy compounds are more preferable. The thermosetting resin may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

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

Examples of the polyfunctional epoxy compound include: epoxidizing a vegetable oil; bisphenol a type epoxy resin; hydroquinone type epoxy resins; bisphenol type epoxy resins; thioether type epoxy resins; brominated epoxy resins; a novolac type epoxy resin; a diphenol novolak-type epoxy resin; bisphenol F type epoxy resins; hydrogenated bisphenol a type epoxy resin; glycidyl amine type epoxy resins; hydantoin type epoxy resins; an alicyclic epoxy resin; trihydroxyphenyl methane type epoxy resin; a bixylenol-type or biphenol-type epoxy resin or a mixture thereof; bisphenol S type epoxy resin; bisphenol a novolac type epoxy resin; tetrahydroxyphenylethane-type epoxy resins; a heterocyclic epoxy resin; diglycidyl phthalate resin; tetraglycidyl toloyl ethane resin; a naphthyl-containing epoxy resin; an epoxy resin having a dicyclopentadiene skeleton; glycidyl methacrylate copolymer epoxy resin; a copolymerized epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivatives; CTBN-modified epoxy resins, etc., but are not limited thereto. These epoxy resins may be used alone in 1 kind, or in combination of 2 or more kinds. Among them, particularly preferred are novolak type epoxy resins, bisphenol type epoxy resins, bixylenol type epoxy resins, biphenol novolak type epoxy resins, naphthalene type epoxy resins, or mixtures thereof.

Examples of the polyfunctional oxetane compound include bis [ (3-methyl-3-oxetanylmethoxy) methyl ] ether, bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] ether, 1, 4-bis [ (3-methyl-3-oxetanylmethoxy) methyl ] benzene, 1, 4-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate, methyl (3-methyl-3-oxetanyl) methacrylate, methyl (3-ethyl-3-oxetanyl) methacrylate, methyl (3-oxetanyl) acrylate, and the like, In addition to polyfunctional oxetanes such as oligomers and copolymers thereof, there may be mentioned etherates of oxetanol and hydroxyl group-containing resins such as novolak resins, poly (p-hydroxystyrene), Cardo-type bisphenols, calixarenes, and silsesquioxanes. Further, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate, and the like can be mentioned.

Examples of the compound having a plurality of cyclic thioether groups in the molecule include bisphenol a type episulfide resins and the like. Alternatively, an episulfide resin or the like in which an oxygen atom of an epoxy group of a novolac epoxy resin is replaced by a sulfur atom by the same synthesis method can be used.

Examples of the amino resin such as a melamine derivative and a benzoguanamine derivative include methylolmelamine compounds, methylolbenzoguanamine compounds, methylolglycoluril compounds, methylolurea compounds, and the like.

As the isocyanate compound, a polyisocyanate compound may be compounded. Examples of the polyisocyanate compound include aromatic polyisocyanates such as 4, 4' -diphenylmethane diisocyanate, 2, 4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, naphthalene-1, 5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, and 2, 4-tolylene diisocyanate dimer; aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate; alicyclic polyisocyanates such as bicycloheptane triisocyanate; and adducts, biurets, isocyanurates and the like of the above-exemplified isocyanate compounds.

As the blocked isocyanate compound, an addition reaction product of an isocyanate compound and an isocyanate blocking agent may be used. Examples of the isocyanate compound capable of reacting with the isocyanate blocking agent include the polyisocyanate compounds described above. Examples of the isocyanate blocking agent include phenol blocking agents; a lactam-based blocking agent; an active methylene-based blocking agent; an alcohol-based blocking agent; an oxime-based blocking agent; a thiol-based blocking agent; an amide-based blocking agent; an imide-based end-capping agent; an amine-based blocking agent; an imidazole-based capping agent; and an imine-based blocking agent.

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

(curing accelerators)

The curable resin composition of the present invention may contain a curing accelerator. Examples of the curing accelerator include imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, and 4-dimethylaminopyridine, and hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; phosphorus compounds such as triphenylphosphine, and the like. In addition, s-triazine derivatives such as 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/isocyanuric acid adduct, and 2, 4-diamino-6-methacryloyloxyethyl-s-triazine/isocyanuric acid adduct can also be used. The curing accelerator may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

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

(coloring agent)

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 may be used, and any of pigments, dyes, and pigments may be used. Among them, it is preferable not to contain halogen from the viewpoint of reducing environmental load and influence on human body. The colorant may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

The 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. As organic solvents, it is possible to use: ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; and known and commonly used organic solvents such as petroleum solvents including petroleum ether, petroleum naphtha, solvent naphtha, and the like. These organic solvents may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

(other optional ingredients)

Further, other additives commonly used in the field of electronic materials may be added to the curable resin composition of the present invention. Examples of the other additives include a thermal polymerization inhibitor, an ultraviolet absorber, a silane coupling agent, a plasticizer, a flame retardant, an antistatic agent, an anti-aging agent, an antioxidant, an antibacterial/antifungal agent, a defoaming agent, a leveling agent, a thickener, an adhesion imparting agent, a thixotropy imparting agent, a photoinitiating auxiliary agent, a sensitizer, an organic filler, an elastomer, a thermoplastic resin, a mold release agent, a surface treating agent, a dispersant, a dispersing auxiliary agent, a surface modifier, a stabilizer, and a phosphor.

The curable resin composition of the present invention may contain an alkali-soluble resin other than the photocurable resin (a) and a solvent-soluble resin within a range not to impair the effects of the present invention.

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

Any component contained in the curable resin composition of the present invention may be selected from known and commonly used components depending on the curability and the application.

The curable resin composition of the present invention may be used in the form of a dry film or in the form of a liquid. When the liquid is used, the liquid may be 1-liquid or 2-liquid 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 the same. In forming a dry film, the curable resin composition of the present invention is first diluted with the organic solvent to adjust the viscosity to an appropriate value, and then coated on a carrier film in a uniform thickness by means of a comma coater, a knife coater, a lip coater, a bar coater, an extrusion coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater, or the like. Thereafter, the coated composition is dried at a temperature of 40 to 130 ℃ for 1 to 30 minutes to form a resin layer. The coating film thickness is not particularly limited, and is usually selected appropriately within a range of 3 to 150 μm, preferably 5 to 60 μm, in terms of the film thickness after drying.

As the carrier film, a plastic film may be 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 may be used. The thickness of the carrier film is not particularly limited, and is generally appropriately selected within a range of 10 to 150 μm. More preferably 15 to 130 μm.

After forming the resin layer formed of the curable resin composition of the present invention on the carrier film, a releasable cover film is preferably further laminated on the surface of the resin layer in order to prevent adhesion of dust and the like to the surface of the resin layer. Examples of the peelable cover film include a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, and surface-treated paper. The cover film may be smaller than the adhesion between the resin layer and the carrier film when the cover film is peeled.

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

As a method for producing a printed wiring board using the curable resin composition of the present invention, a conventionally known method can be used. In the case of an alkali development type photocurable and thermosetting resin composition, for example, the curable resin composition of the present invention is adjusted to a viscosity suitable for a coating method using the above organic solvent, and coated on a substrate by a method such as dip coating, flow coating, roll coating, bar coating, screen printing, or curtain coating, and then the organic solvent contained in the composition is evaporated and dried (temporary drying) at a temperature of 60 to 100 ℃. In the case of a dry film, the resin layer is formed on the substrate by laminating the resin layer on the substrate in contact with the substrate using a laminator or the like, and then peeling off the carrier film.

Examples of the substrate include a printed wiring board and a flexible printed wiring board on which a circuit is formed in advance using copper or the like, and further include: copper-clad laminates of all grades (FR-4 and the like) using materials such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth/nonwoven fabric epoxy, glass cloth/paper epoxy, synthetic fiber epoxy, and high-frequency circuit copper-clad laminates using fluorine resin, polyethylene, polyphenylene oxide (polyphenylene oxide), cyanate ester, and metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates, and the like. The circuit may be subjected to a pretreatment, for example, a pretreatment such as a pretreatment of GliCAP manufactured by four kingdom chemical company, New Organic AP (additive promoter) manufactured by MEC corporation, Nova Bond manufactured by Atotech Japan corporation, or the like, to improve Adhesion between a solder resist or the like and a cured coating film, or a pretreatment of a rust preventive agent.

The volatilization drying after the application of the curable resin composition of the present invention can be carried out by a hot air circulation type drying oven, an IR oven, a hot plate, a convection oven, or the like (a method of bringing hot air in a drying machine into convection contact by using a device having a heat source of an air heating system using steam and a method of blowing the hot air onto a support by using a nozzle).

After a resin layer is formed on a printed wiring board, the resin layer is selectively exposed to active energy rays through a photomask having a predetermined pattern formed thereon, and the unexposed portion is developed with a dilute aqueous alkali solution (for example, a 0.3 to 3 mass% aqueous sodium carbonate solution) to form a pattern of a cured product. Furthermore, the cured product is irradiated with an active energy ray and then cured by heating (for example, 100 to 220 ℃), or is irradiated with an active energy ray after being cured by heating, or is finally cured by only curing by heating (main curing), whereby a cured film having excellent properties such as adhesiveness and hardness is formed.

The exposure machine used for the irradiation with the active energy ray may be a device that is equipped with a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, or the like and irradiates the active energy ray within a range of 350 to 450nm, and a projection exposure machine or a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser beam using CAD data from a computer) that uses a projection lens as a maskless exposure that does not contact the substrate may be used. As a lamp light source or a laser light source of the line drawing machine, the maximum wavelength can be in the range of 350-450 nm. The exposure amount for image formation varies depending on the film thickness, and generally 10 to 1000mJ/cm²Preferably 20 to 800mJ/cm²Within the range of (1).

The developing method may be a dipping method, a spraying method, a brush coating method, or the like, and the developing solution may be an aqueous alkali solution such as potassium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, or amines.

The curable resin composition of the present invention is suitably used for forming a cured film on an electronic component, particularly a cured film on a printed wiring board, more preferably a permanent coating film, and further preferably a solder resist layer, an interlayer insulating layer, a cover layer, or a sealing material. Further, the method is suitable for forming a permanent coating (particularly, a solder resist) for a printed wiring board, for example, a package substrate, particularly FC-BGA, which requires high reliability. The curable resin composition of the present invention can also be suitably used for printed wiring boards having wiring patterns even when the circuit surface roughness is small, for example, printed wiring boards for high frequency applications. For example, the surface roughness Ra is 0.05 μm or less, particularly 0.03 μm or less, and can be suitably used. In addition, a cured film can be suitably used when formed on a substrate having low polarity, for example, a substrate containing an active ester. Further, the method is also suitable for forming a cured film on a wafer or a glass substrate without roughening.

Examples

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the following, all of the terms "part(s)" and "%" are based on mass unless otherwise specified.

[ Synthesis of Photocurable resin ]

(Photocurable resin A-1)

Into a flask equipped with a condenser and a stirrer, 456 parts of bisphenol A, 228 parts of water and 649 parts of 37% formalin were charged, and while maintaining the temperature at 40 ℃ or lower, 228 parts of a 25% aqueous sodium hydroxide solution was added, followed by reaction at 50 ℃ for 10 hours after the completion of the addition. After completion of the reaction, the reaction mixture was cooled to 40 ℃ and kept at 40 ℃ to neutralize the reaction mixture with 37.5% phosphoric acid aqueous solution until the pH was 4. Then, the mixture was allowed to stand, and the aqueous layer was separated. After separation, 300 parts of methyl isobutyl ketone was added and uniformly dissolved, and then the mixture was washed 3 times with 500 parts of distilled water, and water, a solvent and the like were removed at a temperature of 50 ℃ or lower under reduced pressure. The obtained polymethylol compound was dissolved in 550 parts of methanol to obtain 1230 parts of a methanol solution of the polymethylol compound.

A part of the obtained methanol solution of the polymethylol compound was dried in a vacuum drier at room temperature, and the solid content was 55.2%.

Into a flask equipped with a condenser and a stirrer, 500 parts of the obtained methanol solution of the polymethylol compound and 440 parts of 2, 6-xylenol were charged and uniformly dissolved at 50 ℃. After the homogeneous dissolution, methanol was removed under reduced pressure at a temperature of 50 ℃ or lower. Then, 8 parts of oxalic acid was added thereto, and the mixture was reacted at 100 ℃ for 10 hours. After the completion of the reaction, the distillate was removed at 180 ℃ under a reduced pressure of 50mmHg to obtain 550 parts of a novolak resin A.

130 parts of novolak resin a, 2.6 parts of a 50% aqueous sodium hydroxide solution, and 100 parts of toluene/methyl isobutyl ketone (mass ratio: 2/1) were charged into an autoclave equipped with a thermometer, a nitrogen gas introducing device and an alkylene oxide introducing device, and a stirring device, and the inside of the system was replaced with nitrogen gas while stirring, and then heated to raise the temperature, at 150 ℃²Then, 60 parts of propylene oxide was gradually introduced to carry out the reaction. The reaction was continued for about 4 hours until the gauge pressure became 0.0kg/cm²After that, it was cooled to room temperature. To the reaction solution, 3.3 parts of a 36% aqueous hydrochloric acid solution was added and mixed to neutralize sodium hydroxide. The neutralized reaction product was diluted with toluene, washed with water 3 times, and desolventized in an evaporator to obtain a propylene oxide adduct of novolak a resin having a hydroxyl value of 189g/eq. Which is obtained by adding 1 mole of propylene oxide on average to 1 equivalent of phenolic hydroxyl group.

189 parts of the obtained propylene oxide adduct of novolak a resin, 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 charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, stirred while blowing air, heated to 115 ℃ while distilling off the water produced by the reaction and toluene as an azeotropic mixture, reacted for a further 4 hours, and then cooled to room temperature. The obtained reaction solution was washed with 5% NaCl aqueous solution, toluene was removed by reduced pressure distillation, and then diethylene glycol monoethyl ether acetate was added to obtain an acrylate resin solution having a solid content of 67%.

Then, 322 parts of the obtained acrylic resin solution, 0.1 part of hydroquinone monomethyl ether, and 0.3 part of triphenylphosphine were put into a four-necked flask equipped with a stirrer and a reflux condenser, and the mixture was heated to 110 ℃, 60 parts of tetrahydrophthalic anhydride was added thereto, reacted for 4 hours, cooled, and taken out. The photosensitive carboxyl group-containing resin solution A-1 thus obtained had a solid content of 70% and a solid acid value of 81 mgKOH/g. The numerical values shown in table 1 represent parts by mass of the solid content not containing a solvent.

(Photocurable resin A-2)

To a separable flask equipped with a condenser as a reaction vessel, 81.5 parts of carbitol acetate was charged, and after nitrogen substitution, the temperature was raised to 80 ℃. 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, 21 parts of acrylic acid and 10.6 parts of carbitol acetate were mixed in the dropping tank 3, and 10 parts of LUPEROX 11 (trade name; hydrocarbon solution containing 70% t-butyl peroxypivalate, manufactured by ARKEMA Yoshitomi) and 21.2 parts of carbitol acetate were mixed in the dropping tank 4. While the reaction temperature was maintained at 80 ℃, the reaction solution was dropwise added from the dropwise addition tanks 1,2, and 4 over 3 hours, and from the dropwise addition tank 3 over 2.5 hours. After the completion of the dropwise addition, the reaction was continued at 80 ℃ for further 30 minutes. Thereafter, the reaction temperature was raised to 95 ℃ and the reaction was continued for 1.5 hours to obtain a polymer solution before the reaction of introducing a radical polymerizable double bond.

Then, 9.9 parts of glycidyl methacrylate, 7.4 parts of carbitol acetate, 0.7 part of triphenylphosphine as a reaction catalyst, and 0.2 part of ANTAGE W-400 (manufactured by Kayokoku chemical Co., Ltd.) as a polymerization inhibitor were added to the polymer solution, and the mixture was reacted at 115 ℃ 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. The photosensitive carboxyl group-containing copolymer resin had a solid content of 32% and a solid acid value of 120 mgKOH/g. The numerical values shown in table 1 represent parts by mass of the solid content not containing a solvent.

(Photocurable resin A-3)

To 700g of diethylene glycol monoethyl ether acetate, 1070g of o-cresol novolak type epoxy resin [ available from DIC, EPICLON N-695, softening point 95 ℃, epoxy equivalent 214, average functional group number 7.6 ], 1070g (number of glycidyl groups (total number of aromatic rings): 5.0 mol), 360g (5.0 mol) of acrylic acid, and 1.5g of hydroquinone were charged, and the mixture was heated to 100 ℃ and stirred to dissolve uniformly. Subsequently, 4.3g of triphenylphosphine was charged, the mixture was heated to 110 ℃ and reacted for 2 hours, and then 1.6g of triphenylphosphine was added thereto, and the temperature was raised to 120 ℃ and the reaction was further carried out for 12 hours. 562g of aromatic hydrocarbon (SOLVESSO 150) and 684g (4.5 moles) of tetrahydrophthalic anhydride were charged into the obtained reaction solution, and the reaction was carried out at 110 ℃ for 4 hours. Further, 142.0g (1.0 mol) of glycidyl methacrylate was added to the obtained reaction solution, and the reaction was carried out at 115 ℃ 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 numerical values shown in table 1 represent parts by mass of the solid content not containing a solvent.

[ preparation of inorganic Filler ]

C-1：

A silica solvent dispersion C-1 was obtained by uniformly dispersing 60g of spherical silica (SFP-20M manufactured by Denka Company Limited, average particle diameter: 400nm), 40g of MEK (methyl ethyl ketone) as a solvent, and 2g of a silane coupling agent having a methoxy group (KBM-202 SS manufactured by shin-Etsu chemical Co., Ltd.: refractive index under D ray (25 ℃ C.)) in this order.

C-2：

A silica solvent dispersion C-2 was obtained by uniformly dispersing 60g of spherical silica (SFP-20M manufactured by Denka Company Limited, average particle diameter: 400nm), 40g of MEK (methyl ethyl ketone) as a solvent, and 2g of a silane coupling agent (Osaka Gas Chemicals Co., Ltd., SC-001 manufactured by Ltd.: refractive index 1.56 under D-ray (25 ℃)) having a methoxy group and a fluorene skeleton having a Cardo structure.

C-3：

A silica solvent dispersion C-3 was obtained by uniformly dispersing 60g of spherical silica (SFP-20M manufactured by Denka Company Limited, average particle diameter: 400nm), 40g of MEK (methyl ethyl ketone) as a solvent, and 2g of a silane coupling agent (Osaka Gas Chemicals Co., Ltd., SC-003 manufactured by Ltd.: refractive index under D-ray (25 ℃) of 1.53) having a methoxy group and a fluorene skeleton having a Cardo structure.

C-4：

After 60g of spherical silica (SFP-20M manufactured by Denka Company Limited, average particle diameter: 400nm), 40g of MEK (methyl ethyl ketone) as a solvent, and 2g of a silane coupling agent having a methoxy group and a fluorene skeleton having a Cardo structure (refractive index 1.56 under D-ray (25 ℃) of Osaka Gas Chemicals Co., Ltd., SC-001 manufactured by Ltd.), 1g of a silane coupling agent having a methoxy group and a methacryloyl group (refractive index 1.43 under D-ray (25 ℃) was uniformly dispersed, a silica solvent dispersion C-4 was obtained.

C-5：

After 60g of spherical silica (SFP-20M manufactured by Denka Company Limited, average particle diameter: 400nm), 40g of MEK (methyl ethyl ketone) as a solvent, and 2g of a silane coupling agent having a methoxy group and a fluorene skeleton having a Cardo structure (refractive index 1.56 under D-ray (25 ℃) of Osaka Gas Chemicals Co., Ltd., SC-001 manufactured by Ltd.), 1g of a silane coupling agent having a methoxy group and an amino group (refractive index 1.43 under D-ray (25 ℃) of KBM-573 manufactured by shin-Etsu chemical Co., Ltd.) were uniformly dispersed, a silica solvent dispersion C-5 was obtained.

R-1：

A silica solvent dispersion R-1 was obtained by uniformly dispersing 60g of spherical silica (SFP-20M manufactured by Denka Company Limited, average particle diameter: 400nm), 40g of MEK (methyl ethyl ketone) as a solvent, and 2g of a silane coupling agent having a methoxy group and a methacryloyl group (KBM-503 manufactured by shin-Etsu chemical Co., Ltd.: refractive index under D-ray (25 ℃ C.)) was obtained.

R-2：

A silica solvent-dispersed product R-2 was obtained by uniformly dispersing 60g of spherical silica (SFP-20M manufactured by Denka Company Limited, average particle diameter: 400nm, refractive index at 25 ℃ C. of D-ray: 1.42) and 40g of MEK (methyl ethyl ketone) as a solvent.

R-3：

Barium sulfate (made by Sakai chemical industry Co., Ltd., B-30NC (surface-untreated product), average particle diameter: 300nm, refractive index at 25 ℃ C. of D-ray of 1.65)60g, and MEK (methyl ethyl ketone) 40g as a solvent were uniformly dispersed to obtain a barium solvent dispersion R-3.

These were compounded so as to be solid contents of numerical values of examples and comparative examples.

< method for measuring refractive index >

The refractive indices of the photocurable resin, the organoalkoxysilane, and the inorganic filler adjusted as described above were measured as follows: each sample was coated on a glass with a refractometer ER-7MW manufactured by ERMA, dried, and measured under the conditions of D-ray and 25 ℃.

Examples 1 to 6 and comparative examples 1 and 2

The resin solution (varnish) was mixed with each component shown in the table at the ratio (parts by mass) shown, premixed in a mixer, and kneaded by a three-roll mill to prepare a curable resin composition.

< preparation of Dry film >

To the curable resin composition prepared as described above, 300g of methyl ethyl ketone was added and diluted, and the mixture was stirred in a stirrer for 15 minutes to obtain a coating liquid. The coating liquid was applied to a polyethylene terephthalate film (carrier film: Emblet PTH-25 manufactured by UNITIKA) having a thickness of 38 μm, and dried at a temperature of 80 ℃ for 15 minutes to form a resin layer having a thickness of 20 μm. Then, a biaxially stretched polypropylene film (cover film: OPP-FOA manufactured by FUTAMURA) was bonded to the resin layer to prepare a dry film.

< resolution >

The copper clad laminates were prepared by laminating copper of the acid-treated copper clad laminates of the dry films of examples and comparative examples in a vacuum laminator (CVP-600: Nikko-Materials Co., Ltd.) in a first chamber at 100 ℃ under a vacuum pressure of 3hPa for a vacuum time of 30 seconds, and then pressing the laminate under a pressing pressure of 0.5MPa for a pressing time of 30 seconds to obtain an evaluation substrate. Then, the exposure was performed by a DI exposure machine (light source: mercury short arc lamp) to obtain an exposure of 10 stages in a stepwise exposure table (41 stages) to form an aperture pattern of phi 30 μmAfter that, the PET film was peeled off and developed for 60 seconds (1 mass% Na)₂CO₃30 ℃ and 0.2MPa) to form a pattern of the resin layer. Then, the mixture was heated in a UV conveyor furnace equipped with a high-pressure mercury lamp at a rate of 1J/cm²After the resin layer was irradiated with the exposure amount of (2), the resin layer was completely cured by heating at 160 ℃ for 60 minutes to prepare an evaluation substrate having a patterned cured film, and the length of the photosensitive cured film was measured.

Very good: top30 μm, Bottom opening 95-100%

Good: top30 μm, Bottom opening 85% above and below 95%

And (delta): top and Bottom both have opening precision of 80-90%

X: halation and undercut

< embeddability and BHAST resistance >

After the substrate having a circuit pattern formed thereon and having a conductor thickness of 10 μm L/S of 8 μm/8 μm was subjected to acid treatment, the dry film was laminated, exposed, developed, and cured in the same manner as in the above < resolution > evaluation, and after the embeddability was confirmed, BHAST was performed at 130 ℃, 85%, and 3V to evaluate the insulation reliability.

Very good: buried without a gap to achieve insulation reliability of BHAST over 300hrs

Good: buried without a gap, and achieves insulation reliability of BHAST200 or more and less than 300hrs

And (delta): voids of about 1 to 2 μm were observed, and the insulation resistance was less than 200hrs

X: a hollow of 5 μm or more was observed (Japanese: pulled け).

< high temperature Placement test >

The copper of the copper-clad laminate treated with CZ8101 (manufactured by MEC corporation) for the dry films of the examples and comparative examples was laminated in a vacuum laminator (CVP-600: manufactured by Nikko-Materials corporation) in a first chamber at 100 ℃ under a vacuum pressure of 3hPa for 30 seconds, and then pressed under a pressing pressure of 0.5MPa for 30 seconds to obtain an evaluation substrate. Then, in the DI exposure machine, the exposure was performed so as to form a hollow pattern of 200 μm in diameter by obtaining 10 exposure amounts in a stepwise exposure table (41 stages),the PET film was peeled off and developed for 60 seconds (1% by mass of Na)₂CO₃30 ℃ and 0.2MPa) to form a pattern of the resin layer. Then, the mixture was heated in a UV conveyor furnace equipped with a high-pressure mercury lamp at a rate of 1J/cm²After the resin layer was irradiated with the exposure amount of (2), the resin layer was completely cured by heating at 160 ℃ for 60 minutes, thereby producing an evaluation substrate having a patterned cured film.

The substrate was placed in a thermostatic bath at 175 ℃ in an oxygen atmosphere, and it was confirmed that the peeling of the transparent adhesive tape did not occur.

Very good: no peeling after 2000hrs

Good: some peeling occurred above 1500hrs and below 2000hrs

And (delta): peeling occurs at 1000hrs or more and less than 1500hrs

X: peeling occurs within 1000hrs

＜CTE＞

A cured film was formed on the low profile copper foil under the same conditions as in the above-mentioned high temperature standing test. The cured film thus obtained was peeled from the copper foil, and a sample was cut out so as to have a measurement size (3 mm. times.10 mm size), and the CTE was measured by TMA6100 manufactured by Hitachi High-Tech Co. The measurement conditions were as follows: the sample was heated from room temperature at a temperature rise rate of 10 ℃/min 2 times at a test load of 5g, and the coefficient of linear expansion (CTE (α 2)) of Tg or less was obtained for the 2 nd time. The smaller the CTE, the more excellent the thermal stability.

Very good: less than 30ppm

Good: more than 30ppm and not more than 40ppm

And (delta): more than 40ppm and not more than 50ppm

X: over 50ppm

< evaluation of Cold Heat resistance >

On the BT substrate on which the copper line pattern of 2mm was formed, dry films were laminated in the same manner as in the above evaluation of < high temperature standing test > and < resolution > and exposure, development, UV and heat curing were performed. The pattern during exposure was changed to a 3mm square cured film pattern, and an evaluation substrate having a 3mm square cured film pattern formed on a copper wire was produced. The substrate was put into a Thermal cycler for temperature cycling between-50 ℃ and 150 ℃ to perform TCT (Thermal Cycle Test). Then, cracks were confirmed when the evaluation was performed up to 1000 cycles.

Very good: no cracking occurred until 1000 cycles.

Good: cracks occur at 500-750 cycles.

And (delta): cracking occurred above 250 cycles and below 500 cycles.

X: cracking occurred at less than 250 cycles.

[ Table 1]

In example 2, the difference between the refractive index of the photocurable resin (a) and that of the organoalkoxysilane at D-ray (25 ℃) is 2

*1: solution A-1 (refractive index at D ray (25 ℃) of 1.56) of the photocurable resin synthesized above

*2: solution A-2 (refractive index at D ray (25 ℃) of the photocurable resin synthesized in the above: 1.55)

*3: solution A-3 (refractive index under D ray (25 ℃) of 1.56) of the photocurable resin synthesized in the above

*4: omnirad TPO (2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide) manufactured by IGM Resins Co., Ltd

*5: omnirad907 (2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinopropan-1-one, manufactured by IGM Resins Co., Ltd.)

*6: DPHA manufactured by Nippon chemical Co., Ltd. (dipentaerythritol hexaacrylate, refractive index at D ray (25 ℃ C.). 1.48)

*7: JeR828 (bisphenol A epoxy resin) manufactured by Mitsubishi Chemical company

*8: NC-6000 (glycidyl ether compound of 2- (4-hydroxyphenyl) -2- [4- [1, 1-bis (4-hydroxyphenyl) ethyl ] phenyl ] propane, manufactured by Nippon Chemicals Co., Ltd.)

*9: NC-3000H (bisphenol novolac type epoxy resin) manufactured by Nippon Chemicals Co., Ltd

*10: phthalocyanine blue

*11: dicyandiamide

*12: melamine

C-1: the solvent dispersion C-1 of silica prepared as described above and covered with a silane coupling agent having a methoxy group (refractive index at D ray (25 ℃ C.) of 1.54)

C-2: the solvent dispersion C-2 of silica prepared as described above and covered with a silane coupling agent (refractive index 1.56 under D-ray (25 ℃ C.)) having a methoxy group and a fluorene skeleton having a Cardo structure

C-3: the solvent dispersion C-3 of silica prepared as described above and covered with a silane coupling agent (refractive index 1.53 under D-ray (25 ℃ C.)) having a methoxy group and a fluorene skeleton having a Cardo structure

C-4: the solvent dispersion C-4 of silica prepared as described above and covered with a silane coupling agent having a methoxy group and a fluorene skeleton having a Cardo structure (refractive index 1.56 under D-ray (25 ℃) and a silane coupling agent having a methoxy group and a methacryloyl group (refractive index 1.43 under D-ray (25 ℃))

C-5: the solvent dispersion C-5 of silica prepared as described above and covered with a silane coupling agent having a methoxy group and a fluorene skeleton having a Cardo structure (refractive index 1.56 under D-ray (25 ℃) and a silane coupling agent having a methoxy group and an amino group (refractive index 1.43 under D-ray (25 ℃))

R-1: the solvent dispersion R-1 of silica prepared as described above and covered with a silane coupling agent having a methoxy group and a methacryloyl group (refractive index at 25 ℃ C. of 1.43) having a D-ray index of refraction

R-2: the solvent dispersion R-2 of silica (refractive index at 25 ℃ C.) adjusted as described above

R-3: the solvent dispersion R-3 of barium (refractive index at 25 ℃ C. of 1.65) adjusted as described above

From the results shown in the above tables, it is understood that the curable resin compositions of examples 1 to 6 of the present invention can give cured products excellent in resolution and embeddability of high-density wiring patterns.