CN117908328A - Photosensitive resin composition, dry film, cured product, and printed wiring board - Google Patents

Abstract

The invention provides a photosensitive resin composition which suppresses the reduction of film physical properties such as elastic modulus and has excellent storage stability. A photosensitive resin composition comprising at least (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) silica, and (D) a photopolymerizable monomer, wherein the (C) silica is a surface-treated silica obtained by subjecting both of a silane coupling agent having no reactive functional group and a silane coupling agent having at least one reactive functional group selected from the group consisting of a vinyl group, (meth) acryl group and a styryl group.

Description

Photosensitive resin composition, dry film, cured product, and printed wiring board

Technical Field

The present invention relates to a photosensitive resin composition, and more particularly, to a photosensitive resin composition which can be suitably used for forming an insulating layer such as a solder resist, a dry film using the photosensitive resin composition, a cured product of the photosensitive resin composition or the dry film, and a printed wiring board using the cured product.

Background

In general, in a printed wiring board used for an electronic device or the like, a solder resist layer is formed in a region other than a connection hole on a substrate on which a circuit pattern is formed, so as to prevent solder from adhering to an unnecessary portion of the printed wiring board in a step of solder reflow or the like when an electronic component is mounted on the printed wiring board. The main flow of the solder resist layer is a so-called photoresist layer formed of a photoresist, which is a layer of a photosensitive resin composition applied to a substrate and dried, exposed to light, developed to form a pattern, and then cured by heating or light irradiation. In addition, it has been proposed to form a solder resist layer using a photosensitive dry film without using the liquid photosensitive resin composition described above.

These photosensitive resin compositions and photosensitive dry films contain an alkali-soluble photosensitive resin component so as to be able to be exposed and developed, and if necessary, contain other photopolymerizable monomers, or contain a thermosetting component such as epoxy in view of heat resistance, substrate adhesion, and the like. In addition, an inorganic filler may be blended in the photosensitive resin composition to reduce the linear expansion coefficient, thereby suppressing peeling of the solder resist layer and warpage of the substrate (japanese patent application laid-open No. 2001-72834, etc.).

Among inorganic fillers, spherical silica has excellent filling properties and a low coefficient of thermal expansion, and is therefore widely used for improving the characteristics of solder resists. However, as the amount of the inorganic filler blended increases, the interface between the inorganic filler and the resin increases, and thus there is a tendency that the physical properties of the coating film such as elastic modulus and tensile strength are lowered. Therefore, even in the case of silica having high filling properties, the reduction of the physical properties of the coating film is suppressed by surface treatment with a silane coupling agent having a reactive functional group such as an amino group or a (meth) acryloyl group (japanese patent application laid-open No. 2018-165795).

Disclosure of Invention

The surface treatment of silica is performed by adding a silane coupling agent to silica to react the silica, and the silica is blended in the photosensitive resin composition in the form of a silica slurry containing the silane coupling agent. Therefore, there are cases where free silane coupling agents contained in the silica slurry undergo condensation reaction with each other and react with the resin component in the photosensitive resin composition, and there are cases where not only the storage stability is lowered but also the crosslinking density of the resin component is affected and the sensitivity of the photosensitive resin composition is lowered. In addition, when the photosensitive resin composition is stored for a long period of time, components in the photosensitive resin composition react with a free silane coupling agent, and the sensitivity of the photosensitive resin composition may be abnormally increased.

Accordingly, an object of the present invention is to provide a photosensitive resin composition which suppresses a decrease in physical properties of a coating film such as an elastic modulus and is excellent in storage stability.

The present inventors have studied the above problems and as a result, have obtained the following knowledge: by using silica surface-treated with two silane coupling agents, i.e., a silane coupling agent having a reactive functional group and a silane coupling agent having no reactive functional group, a photosensitive resin composition having excellent storage stability can be obtained while suppressing the deterioration of the physical properties of a coating film. The present invention has been completed based on this knowledge. Namely, the gist of the present invention is as follows.

[1] A photosensitive resin composition comprising at least (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) silica, and (D) a photopolymerizable monomer, wherein the (C) silica is a surface-treated silica obtained by subjecting both of a silane coupling agent having no reactive functional group and a silane coupling agent having at least one reactive functional group selected from the group consisting of a vinyl group, (meth) acryl group and a styryl group.

[2] The photosensitive resin composition according to [1], wherein the amount of the silica coated with the silane coupling agent having the reactive functional group is larger than the amount of the silica coated with the silane coupling agent having no reactive functional group.

[3] The photosensitive resin composition according to [2], wherein in the (C) silica, a ratio of an amount coated by the silane coupling agent having the reactive functional group to an amount coated by the silane coupling agent having no reactive functional group is 2 on a mass basis: 1 to 10:1.

[4] The photosensitive resin composition according to [1], wherein the photosensitive resin composition contains the (C) silica in a proportion of 50 to 90 mass% relative to the total solid content in the photosensitive resin composition.

[5] The photosensitive resin composition according to [1], wherein the photosensitive resin composition further comprises (E) a thermosetting component.

[6] A dry film, wherein the dry film has: a first film; and a resin layer formed by coating the photosensitive resin composition of [1] on one surface of the first film and drying the coated film.

[7] A cured product obtained by curing the photosensitive resin composition according to any one of [1] to [5] or the resin layer of the dry film according to [6 ].

[8] A printed wiring board having a coating film composed of the cured product of [7 ].

According to the present invention, a photosensitive resin composition having excellent storage stability can be obtained by using silica surface-treated with two specific silane coupling agents, while suppressing a decrease in physical properties of a coating film such as elastic modulus.

Detailed Description

[ Photosensitive resin composition ]

The photosensitive resin composition of the present invention comprises at least (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) silica, and (D) a photopolymerizable monomer. The following describes the components constituting the photosensitive resin composition. In the present specification, (meth) acrylic group means a term used to collectively refer to both acrylic group and methacrylic group. In addition, (meth) acryl means that it is used as a term that refers to both acryl and methacryl. Further, (meth) acrylate refers to the use of the term collectively referring to acrylate, methacrylate, and mixtures thereof.

Alkali-soluble resin (A)

The alkali-soluble resin (a) contained in the photosensitive resin composition of the present invention may be any alkali-soluble resin, and any known and customary resin can be used. The alkali-soluble resin can be used singly or in combination of two or more. Examples thereof include water-soluble resins such as carboxyl group-containing resins and phenolic hydroxyl group-containing resins. Among them, the carboxyl group-containing resin and the phenolic hydroxyl group-containing resin are preferable, and the carboxyl group-containing resin is more preferable because of excellent developability. Since the alkali-soluble resin contains a carboxyl group, it can be made alkali developable. In addition, from the viewpoint of photosensitivity, it is preferable to have an ethylenically unsaturated double bond in the molecule in addition to the carboxyl group, and only a carboxyl group-containing resin having no ethylenically unsaturated double bond may be used. In the case where the carboxyl group-containing resin does not have an ethylenically unsaturated double bond, it is necessary to use a photopolymerizable monomer in combination to make the composition photocurable. As the ethylenically unsaturated double bond, ethylenically unsaturated double bonds derived from acrylic acid or methacrylic acid or derivatives thereof are preferred.

Specific examples of the carboxyl group-containing resin include the following compounds (which may be any of oligomers and polymers). In the present specification, (meth) acrylate refers to a term generically referring to acrylate, methacrylate, and a mixture thereof, and other similar expressions are also the same.

(1) Carboxyl group-containing resins obtained by copolymerizing unsaturated carboxylic acids such as (meth) acrylic acid with unsaturated group-containing compounds such as styrene, α -methylstyrene, lower alkyl (meth) acrylate, isobutylene and the like.

(2) Carboxyl group-containing urethane resins produced by the polyaddition reaction of a diisocyanate such as aliphatic diisocyanate, branched aliphatic diisocyanate, alicyclic diisocyanate, or aromatic diisocyanate with a carboxyl group-containing diol compound such as dimethylolpropionic acid or dimethylolbutyric acid, a polycarbonate polyol, a polyether polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, a bisphenol a alkylene oxide adduct glycol, or a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(3) A carboxyl group-containing photosensitive urethane resin produced by the polyaddition reaction of a diisocyanate with a reaction product of a difunctional epoxy resin such as a bisphenol A type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a bisxylenol type epoxy resin, a bisphenol type epoxy resin and a monocarboxylic acid compound having an ethylenically unsaturated double bond such as (meth) acrylic acid, a carboxyl group-containing diol compound and a dihydroxy compound.

(4) In the synthesis of the resin of (2) or (3), a compound having one hydroxyl group and one or more (meth) acryloyl groups is added to a molecule such as hydroxyalkyl (meth) acrylate, and a carboxyl group-containing photosensitive urethane resin obtained by terminal (meth) acrylic acid formation is added.

(5) In the synthesis of the resin of (2) or (3), a carboxyl group-containing photosensitive urethane resin obtained by terminal (meth) acrylic acid formation is carried out by adding a compound having one isocyanate group and one or more (meth) acryloyl groups in the molecule, such as an equimolar reactant of isophorone diisocyanate and pentaerythritol triacrylate.

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

(7) A carboxyl group-containing photosensitive resin is obtained by reacting a (meth) acrylic acid with a polyfunctional epoxy resin obtained by epoxidizing a hydroxyl group of a difunctional (solid) epoxy resin with epichlorohydrin, and adding a dibasic acid anhydride to the hydroxyl group thus formed.

(8) A carboxyl group-containing polyester resin obtained by reacting a difunctional oxetane resin with a dicarboxylic acid such as adipic acid, phthalic acid or hexahydrophthalic acid, and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride or hexahydrophthalic anhydride to the primary hydroxyl group formed.

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

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

(11) A carboxyl group-containing photosensitive resin is 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, reacting the resultant with an unsaturated group-containing monocarboxylic acid, and reacting the resultant with a polybasic acid anhydride.

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

These carboxyl group-containing resins can be used not only as exemplified above but also as 1 kind of resin alone or as a mixture of plural kinds. Among the above, carboxyl group-containing resins synthesized from compounds having phenolic hydroxyl groups such as the carboxyl group-containing resins (10) and (11) as starting materials are preferably used because they are excellent in HAST resistance (high accelerated stress test resistance) and PCT resistance (autoclaving test resistance).

The acid value of the carboxyl group-containing resin is preferably 40 to 150mgKOH/g. The acid value of the carboxyl group-containing resin is set to 40mgKOH/g or more, whereby alkali development is excellent. In addition, by setting the acid value to 150mgKOH/g or less, a good resist pattern can be easily drawn. More preferably 50 to 130mgKOH/g.

The weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, and is usually preferably 2000 to 150000. By setting the weight average molecular weight to 2000 or more, the surface drying performance and resolution can be improved. In addition, when the weight average molecular weight is 150000 or less, the developability and storage stability can be improved. More preferably 5000 to 15000. The weight average molecular weight can be measured by Gel Permeation Chromatography (GPC).

In the photosensitive resin composition, the blending amount of the alkali-soluble resin (a) is preferably 10 to 50% by mass in terms of solid content. By setting the content to 10 mass% or more, the coating film strength can be further improved. Further, by setting the content to 50 mass% or less, the tackiness becomes appropriate, and the printability improves. More preferably 10 to 30 mass%.

(B) photopolymerization initiator

The photosensitive resin composition of the present invention contains (B) a photopolymerization initiator to photopolymerization the alkali-soluble resin (a) and the photopolymerizable monomer (D) described later. As the photopolymerization initiator, a known photopolymerization initiator can be used, and examples thereof include α -aminoacetophenone photopolymerization initiators such as 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2- (dimethylamino) -2- [ (4-methylphenyl) methyl ] -1- [4- (4-morpholino) phenyl ] -1-butanone, and N, N-dimethylaminoacetophenone: hydroxyacetophenone-based photopolymerization initiators 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, 2-hydroxy-2-methyl-1-phenylpropane-1-one, and the like; photo polymerization initiators such as bis- (2, 6-dichlorobenzoyl) phenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -2, 5-xylylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) phenylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2, 4-trimethylpentylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2, 5-xylylphosphine oxide, bis- (2, 4, 6-trimethylbenzoyl) -phenylphosphine oxide, 2, 6-dimethoxybenzoyl diphenylphosphine oxide, 2, 6-dichlorobenzoyl diphenylphosphine oxide, methyl 2,4, 6-trimethylbenzoyl phenylphosphinate, 2-methylbenzoyl diphenylphosphine oxide, pivaloyl phenylphosphinate isopropyl ester, 2,4, 6-trimethylbenzoyl diphenylphosphine oxide and the like; benzoin photopolymerization initiators such as benzoin, benzil, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; a benzoylalkyl ether photopolymerization initiator; benzophenone-based photopolymerization initiators such as benzophenone, p-methylbenzophenone, michler's ketone, methylbenzophenone, 4' -dichlorobenzophenone, and 4,4' -bis-diethylaminobenzophenone; acetophenone photopolymerization initiators of acetophenone, 2-dimethoxy-2-phenylacetophenone, 2-diethoxy-2-phenylacetophenone, 1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholin-1-one; thioxanthone photopolymerization initiators such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-chlorothioxanthone, and 2, 4-diisopropylthioxanthone; anthraquinone photopolymerization initiators such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone, 2-pentynthraquinone, and 2-aminoanthraquinone; ketal photopolymerization initiators such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoate photopolymerization initiators such as ethyl-4-dimethylaminobenzoate, 2- (dimethylamino) ethylbenzoate, and ethyl p-dimethylbenzoate; oxime ester photopolymerization initiators such as 1, 2-octanedione, 1- [4- (phenylthio) phenyl ] -,2- (O-benzoyl oxime) ], ethanone, 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -, and 1- (O-acetyl oxime); 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 and the like; etc. These photopolymerization initiators may be used alone or in combination of two or more.

Examples of commercially available α -aminoacetophenone photopolymerization initiators include Omnirad 907, 369E, 379, and the like manufactured by Ai Jianmeng resins (IGM RESINS b.v.).

As a commercially available acylphosphine oxide-based photopolymerization initiator, omnirad 819, manufactured by Ai Jianmeng resin Co., ltd. (IGM RESINS B.V.), and the like are exemplified.

As commercially available titanocene photopolymerization initiators, JMT-784 manufactured by Yueyang Jin Maotai technology Co., ltd (Yueyang kimoutain Sci Tech Co., ltd.) and GR-FMT manufactured by Hubei solid state technology Co., ltd.) can be mentioned.

In addition, a photopolymerization initiator having 2 oxime ester groups in the molecule can be preferably used, and specifically, oxime ester compounds having a carbazole structure represented by the following general formula (I) can be used.

In the above formula, X represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms or a dialkylamino group), a naphthyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms or a dialkylamino group), Y, Z represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a halogen group, a phenyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having 1 to 8 carbon atoms or a dialkylamino group), a naphthyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having 1 to 8 carbon atoms or a dialkylamino group), an anthryl group, a pyridyl group, a benzofuranyl group or a benzothienyl group, ar represents an alkylene group having 1 to 10 carbon atoms, a vinylidene group, a phenylene group, a biphenylene group, a pyridylene group, a naphthylene group, a thiophene, an anthrylene group, a thienylene group, a2, 5-pyrrole-diyl group, a 4,4 '-stilbene-diyl group, a 4,2' -styrene-diyl group, and n is an integer of 0 or 1.

In particular, in the above formula, X ₁、Y₁ is preferably methyl or ethyl, Z is methyl or phenyl, n is 0, and Ar is phenylene, naphthylene, thiophene or an oxime ester-based photopolymerization initiator of thienyl group, respectively.

In addition to the above photopolymerization initiator, a benzoin compound, an acetophenone compound, an anthraquinone compound, a thioxanthone compound, a ketal compound, a benzophenone compound, a tertiary amine compound, a xanthone compound, or the like can be used as the photopolymerization initiator.

However, it is preferable to use the photopolymerization initiator in combination with the above photopolymerization initiator as a photopolymerization initiator auxiliary or sensitizer, as compared with the case where they are used alone as photopolymerization initiators.

Among them, from the viewpoint of deep curability, thioxanthone compounds and tertiary amine compounds are preferable, and thioxanthone compounds are more preferable. In addition, two or more of the above compounds may be used in combination.

The amount of the photopolymerization initiator (B) to be blended in the photosensitive resin composition is preferably 1 to 50 parts by mass, more preferably 1 to 20 parts by mass, in terms of solid content, per 100 parts by mass of the alkali-soluble resin (a). This can improve the deep curability.

When the photosensitive resin composition contains the benzoin compound or the like as a photopolymerization initiator auxiliary agent, the blending amount thereof is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass in terms of solid content, per 100 parts by mass of the alkali-soluble resin (a). This can improve the deep curability.

Silicon dioxide < (C)

The photosensitive resin composition of the present invention comprises (C) silica. The silica (C) used in the present invention is a silica surface-treated with two silane coupling agents, that is, a silane coupling agent having no reactive functional group and a silane coupling agent having at least one reactive functional group selected from the group consisting of vinyl group, (meth) acryl group and styryl group. In this way, by using silica surface-treated with both a silane coupling agent having no reactive functional group and a silane coupling agent having a specific reactive functional group, a photosensitive resin composition having excellent storage stability can be obtained while suppressing a decrease in physical properties of a coating film such as an elastic modulus. The reason for this is not clear, but can be presumed as follows.

That is, from the viewpoint of improving the physical properties of a coating film such as elastic modulus, it is preferable that the surface of the silica to be blended has a predetermined reactive functional group, and as described above, if the silane coupling agent having a reactive functional group is present as a free silane coupling agent in the photosensitive resin composition, the silane coupling agents may react with each other or react with other components in the photosensitive resin composition, and the storage stability may be deteriorated. Therefore, it is considered that when the amount of the silane coupling agent having a reactive functional group used in the surface treatment of silica is reduced, the storage stability is improved, but the hydrophilicity of the surface-treated silica is enhanced, and problems such as aggregation occur. In the present invention, it is presumed that the silane coupling agent having a reactive functional group among the silane coupling agents coating silica is used to improve the physical properties of the coating film, and the silane coupling agent having no reactive functional group is used to impart hydrophobicity to silica, whereby a photosensitive resin composition having excellent storage stability with suppressed aggregation or the like can be obtained.

Examples of the silane coupling agent having no reactive functional group include Si-containing compounds having an alkoxysilyl group or silanol group, and examples thereof include methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isopropyltrimethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, n-pentyltrimethoxysilane, cyclopentyltrimethoxysilane, n-hexyltrimethoxysilane, cyclohexyltrimethoxysilane, n-octyltrimethoxysilane, isooctyltrimethoxysilane, n-decyltrimethoxysilane, n-dodecyltrimethoxysilane, n-tetradecyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, 7-octyltrimethoxysilane, phenyltrimethoxysilane, benzyltrimethoxysilane, 1-naphthyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, n-propyltriethoxysilane, isopropyltriethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, n-pentyltriethoxysilane, cyclopentyltriethoxysilane, n-hexyltriethoxysilane, cyclohexyltriethoxysilane, n-octyltriethoxysilane, n-decyltrialkylsilane, n-decyltriaethoxysilane, n-triethoxysilane, n-decyltriaethoxysilane. These silane coupling agents having no reactive functional group may be used singly or in combination of two or more. Among them, methyltrimethoxysilane and ethyltrimethoxysilane can be preferably used.

Examples of the silane coupling agent having a reactive functional group include a vinyl-containing silane coupling agent, a (meth) acryl-containing silane coupling agent, and a styryl-containing silane coupling agent. These may be used alone or in combination of two or more.

Examples of the vinyl-containing silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltris (2-methoxyethoxy) silane, vinylmethyldimethoxysilane, octenyltrimethoxysilane, and allyltrimethoxysilane.

In addition, as the silane coupling agent containing a (meth) acryloyl group, examples thereof include 1, 3-bis (acryloyloxymethyl) -1, 3-tetramethyldisilazane, 1, 3-bis (methacryloyloxymethyl) -1, 3-tetramethyldisilazane, 1, 3-bis (gamma-acryloyloxypropyl) -1, 3-tetramethyldisilazane, 1, 3-bis (gamma-methacryloyloxypropyl) -1, 3-tetramethyldisilazane acryloxymethyl methyl trisilazane, methacryloxymethyl trisilazane, acryloxymethyl tetrasilazane, methacryloxymethyl tetrasilazane, acryloxymethyl polysilazane methacryloxymethyl polysilazane, 3-acryloxypropyl methyltrisilazane, 3-methacryloxypropyl methyltrisilazane, 3-acryloxypropyl methyltetrasilazane, 3-methacryloxypropyl methyltetrasilazane, 3-acryloxypropyl methylpolysilazane, 3-methacryloxypropyl methylpolysilazane, acryloxymethyl polysilazane, methacryloxymethyl polysilazane, 3-acryloxypropyl polysilazane, 3-methacryloxypropyl polysilazane, and the like.

Further, as a styrene-group-containing silane coupling agent, p-styryl trimethoxysilane and the like can be mentioned.

Among the above-mentioned silane coupling agents having a reactive functional group, a (meth) acryloyl group-containing silane coupling agent can be used, and for example, methacryloxypropyl trimethoxysilane can be preferably used.

The surface treatment of the silica (C) is preferably performed by adding the silane coupling agent in a proportion of 0.5 to 10 parts by mass, more preferably in a proportion of 0.5 to 2.0 parts by mass, to 100 parts by mass of the silica. The surface treatment of silica can be carried out by preparing a dispersion of silica in an appropriate solvent, adding a predetermined amount of a silane coupling agent to the silica dispersion, and stirring the mixture. Stirring may be performed in a heating environment at a temperature of 50 to 100 ℃ to promote the reaction of the surface treatment.

Preferably, in the silica of (C), the amount of coating by the silane coupling agent having the reactive functional group is larger than the amount of coating by the silane coupling agent having no reactive functional group among the silane coupling agents coated on the surface of the silica. The silane having the coating ratio described above can be obtained, for example, by adjusting the blending amount of the silane coupling agent and the silica dispersion liquid, and performing surface treatment of silica so that the silane coupling agent having a reactive functional group is more than the silane coupling agent having no reactive functional group. In particular, the ratio of the amount coated by the silane coupling agent having a reactive functional group to the amount coated by the silane coupling agent having no reactive functional group is preferably 2 on a mass basis: 1 to 10:1. The silica having the coating ratio as described above can be used, for example, by using a mass ratio of 2:1 to 10:1 and a silane coupling agent having a reactive functional group and a silane coupling agent having no reactive functional group. The presence or absence of the surface treatment can be confirmed by quantifying the free unreacted coupling agent in the silica slurry using LC-MS. The silane coupling agent added was coated approximately 60% -90%.

In addition, when compared with the case where silica and the silane coupling agent are added separately at the same time, a higher effect can be obtained by using the surface-treated silica.

The silica to be surface-treated may be any conventionally known silica, but may be amorphous or crystalline, or may be a mixture of these. Amorphous (fused) silica is particularly preferred.

The average particle diameter (D50) of the silica is preferably 0.1 to 1.0. Mu.m, more preferably 0.4 to 0.8. Mu.m, from the viewpoint of dispersibility and the like. The average particle diameter is a particle diameter obtained by a laser diffraction scattering particle size distribution measurement method under a condition that 50% of the volume is accumulated. The average particle diameter of the silica is a value measured as described above for the silica before the photosensitive resin composition is prepared (preliminary stirring and kneading).

From the viewpoint of film physical properties and the like, the amount of silica blended in the photosensitive resin composition is preferably 50 to 90 mass%, more preferably 60 to 90 mass%, relative to the total solid content in the photosensitive resin composition.

< Inorganic filler >)

The photosensitive resin composition of the present invention may contain other inorganic filler in addition to the silica (C) described above. As the inorganic filler, known inorganic fillers can be used, and examples thereof include talc, mica, alumina, calcium oxide, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, fly ash, dehydrated sludge, kaolin, clay, calcium hydroxide, aluminum hydroxide, magnesium hydroxide, hydrotalcite, aluminum silicate, magnesium silicate, calcium silicate, wollastonite, potassium titanate, magnesium sulfate, calcium sulfate, magnesium phosphate, sepiolite, jin Zhidan, boron nitride, aluminum borate, silica hollow spheres, glass flakes, glass hollow spheres, iron-making slag, copper, iron oxide, sendust (Sendust), alnico magnet (Alnico Magnets), various magnetic powders such as ferrite, cement, glass powder, noiburg silica (Neuburg Siliceous Earth), diatomaceous earth, antimony trioxide, basic magnesium sulfate, water and aluminum, water and gypsum, alum, barium sulfate, and the like. These inorganic fillers may be used alone or in combination of two or more. The inorganic filler other than the silica (C) may be subjected to a surface treatment in the same manner as the silica.

The average particle diameter (D50) of the inorganic filler other than the silica (C) is preferably 0.1 to 100. Mu.m, more preferably 0.1 to 50. Mu.m, from the viewpoint of dispersibility and the like. The average particle diameter is the same as defined above.

The amount of the inorganic filler other than the silica (C) in the photosensitive resin composition can be appropriately adjusted in relation to the amount of the silica (C), and is usually adjusted in the range of 0 to 20 mass%.

< Photopolymerizable monomer >)

The photosensitive resin composition of the present invention comprises (D) a photopolymerizable monomer. The photopolymerizable monomer is a monomer having an ethylenically unsaturated double bond. Examples of the photopolymerizable monomers include conventionally known polyester (meth) acrylates, polyether (meth) acrylates, urethane (meth) acrylates, carbonate (meth) acrylates, epoxy (meth) acrylates, and the like. Specifically, alkyl acrylates such as 2-ethylhexyl acrylate and cyclohexyl acrylate; hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; mono-or diacrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and the like; acrylamides such as N, N-dimethylacrylamide, N-methylolacrylamide, N-dimethylaminopropyl acrylamide, and the like; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate; polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, di (trimethylolpropane), dipentaerythritol and triethylisocyanurate, and polyhydric acrylic esters such as alkylene oxide adducts or epsilon-caprolactone adducts; phenols such as phenoxy acrylate and bisphenol a diacrylate, or polyvalent acrylates such as these alkylene oxide adducts; acrylic esters of glycidyl ethers such as diglycidyl ether, trimethylolpropane triglycidyl ether and triglycidyl isocyanurate; not limited to the foregoing description of the preferred embodiments, the urethane-modified polyester resin composition can be used by appropriately selecting at least one of an acrylic ester and a melamine acrylic ester obtained by directly acrylating a polyol such as a polyether polyol, a polycarbonate diol, a hydroxyl-terminated polybutadiene, or a polyester polyol, or by urethanizing the polyol via a diisocyanate, and each of the methacrylic esters corresponding to the acrylic ester. The photopolymerizable monomers described above can also be used as reactive diluents.

(D) The photopolymerizable monomers may be used singly or in combination of two or more. The amount of the photopolymerizable monomer to be blended is preferably 0.5 to 30 parts by mass in terms of solid content per 100 parts by mass of the alkali-soluble resin (A). When the amount is 0.5 parts by mass or more, the photo-curability is good, and a pattern is easily formed in alkali development after irradiation with active energy rays. When the amount is 30 parts by mass or less, halation is less likely to occur, and good sharpness can be obtained.

(E) thermosetting component

The photosensitive resin composition of the present invention may contain (E) a thermosetting component in addition to the above components. Examples of the thermosetting component include known conventionally used compounds such as isocyanate compounds, blocked isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclic carbonate compounds, epoxy compounds, oxetane compounds, and episulfide resins. Among them, the preferable thermosetting component is an epoxy resin.

Examples of the epoxy resin include bisphenol a type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol a type epoxy resin, brominated bisphenol a type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol a novolac type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, triphenylmethane type epoxy resin, and the like, and they may be used singly or in combination of two or more.

Examples of the commercially available epoxy resins include jER 828, 806, 807, YX8000, YX8034, 834, YD-128, YDF-170, ZX-1059, ST-3000, EPICLON, 835, 840, 850, N-730A, N-695, and RE-306, etc., which are manufactured by Mitsubishi chemical Co., ltd (Mitsubishi Chemical Group Corporation), nippon STEEL CHEMICAL & Material Co., ltd.).

The equivalent of the epoxy group of the epoxy resin in the photosensitive resin composition is preferably 0.5 to 2.5 in terms of solid content relative to 1 equivalent of the carboxyl group-containing resin. By setting the equivalent weight to 0.5 or more, the residue of carboxyl groups in the cured product can be prevented, and good heat resistance, alkali resistance, electrical insulation, and the like can be obtained. Further, by setting the amount of the above-mentioned compound to 2.5 equivalents or less, it is possible to prevent cyclic (thio) ether groups having a low molecular weight from remaining in the dried coating film, and it is possible to satisfactorily secure the strength and the like of the cured product.

When the photosensitive resin composition of the present invention contains a thermosetting component, a thermosetting catalyst for promoting the curing of the thermosetting component may be further contained. Examples of the heat curing catalyst 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, and 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; phosphorus compounds such as triphenylphosphine. Examples of the commercially available compounds include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ and 2P4MHZ (both trade names of imidazole-based compounds) manufactured by Kabushiki Kaisha, san-Apro Ltd., U-CAT 3513N (trade names of dimethylamine-based compounds) manufactured by Apollo Co., ltd., DBU, DBN, U-CAT SA 102 (both trade names of bicyclic amidine compounds) and salts thereof.

The compound is not limited to the above, and may be used alone or in combination of 2 or more, as long as it is a compound that promotes the reaction between at least any 1 of an epoxy group and an oxetane group and a carboxyl group, or a thermosetting catalyst for an epoxy resin and an oxetane compound. In addition, can also use guanamine, acetyl guanamine, benzoguanamine, melamine, 2, 4-two amino-6-methyl acrylamide oxygen ethyl three, 2-vinyl-2, 4-two amino-S three triazine, 2-vinyl-4, 6-two amino-S three triazine isocyanuric acid adduct, 2, 4-two amino-6-methyl acrylamide oxygen ethyl-S three triazine isocyanuric acid adduct and other S three triazine derivatives, preferably used as adhesion agent also function as a compound and a heat curing catalyst.

The heat curing catalyst can be used singly or in combination of two or more. The amount of the thermosetting catalyst to be blended is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass in terms of solid content, per 100 parts by mass of the alkali-soluble resin (a) from the viewpoints of storage stability of the resin composition and heat resistance of the cured coating film.

< Other Components >)

In addition to the above components, the photosensitive resin composition of the present invention may contain, if necessary, at least 1 component selected from the group consisting of a colorant, an elastomer, a mercapto compound, a urethane catalyst, a thixotropic agent, an adhesion promoter, a block copolymer, a chain transfer agent, a polymerization inhibitor, a copper toxicity inhibitor, an antioxidant, an anticorrosive agent, a thickener such as organobentonite and montmorillonite, an antifoaming agent such as a silicone, fluorine and polymer, and a leveling agent, and a flame retardant such as a phosphonate, a phosphate derivative, a phosphazene compound and the like. These can be substances well known in the field of electronic materials.

From the viewpoint of ease of preparation and coatability, an organic solvent may be blended in the photosensitive resin composition of the present invention. As the organic solvent, ketones such as methyl ethyl ketone and cyclohexanone can be used; 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; known conventionally used organic solvents such as petroleum solvents, e.g., petroleum ether, petroleum naphtha, and solvent naphtha. These organic solvents can be used singly or in combination of 1 or more than 2.

The amount of the organic solvent to be blended in the photosensitive resin composition may be appropriately changed depending on the material constituting the photosensitive resin composition, and may be, for example, 30 to 300 parts by mass in terms of solid content relative to 100 parts by mass of the alkali-soluble resin (a).

The photosensitive resin composition of the present invention can be used as a dry film or a liquid. In the case of using the liquid composition as a liquid, the liquid composition may be one-component or two-component or more.

< Dry film >

The photosensitive resin composition of the present invention may be in the form of a dry film having a first film and a resin layer formed on the first film. The first film in the dry film of the present invention is a film that is bonded to at least a resin layer formed of a photosensitive resin composition formed on the dry film when laminated and integrally molded by heating or the like so that the resin layer side contacts a substrate such as a substrate. The first film may be peeled from the resin layer in a process after lamination. In particular, in the present invention, in the step after exposure, it is preferable to peel from the resin layer.

In order to produce a dry film, the photosensitive resin composition of the present invention is diluted with an organic solvent and adjusted to an appropriate viscosity, and the film is coated on a first film to a uniform thickness by a comma coater, a blade coater, a lip coater, a bar coater, a squeeze coater, a reverse coating method, a transfer roll coater, a gravure coater, a spray coater, or the like, and is dried at a temperature of usually 50 to 130 ℃ for 1 to 30 minutes, whereby a film can be obtained. The thickness of the coating film is not particularly limited, and is usually appropriately selected in the range of 1 to 150 μm, preferably 5 to 60 μm, in terms of the film thickness after drying.

The first film may be any known film, and for example, a polyester film such as polyethylene terephthalate or polyethylene naphthalate, a polyimide film, a polyamide imide film, a polypropylene film, a polystyrene film, or a film made of a thermoplastic resin may be preferably used. Among them, polyester films are preferable from the viewpoints of heat resistance, mechanical strength, handleability, and the like. Further, a laminate of these films can be used as the first film.

In addition, from the viewpoint of improving mechanical strength, the thermoplastic resin film as described above is preferably a film extending in a uniaxial direction or a biaxial direction.

The thickness of the first film is not particularly limited, and may be, for example, 10 μm to 150 μm.

After forming the resin layer of the photosensitive resin composition of the present invention on the first film, a second film that can be peeled off is preferably laminated on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer or the like. The second film in the dry film of the present invention is a film that is peeled from the resin layer before lamination when laminated and integrally molded by heating or the like so that the resin layer side of the dry film contacts a substrate such as a substrate.

As the second film that can be peeled off from the resin layer, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used as long as the adhesive force between the resin layer and the second film is smaller than the adhesive force between the resin layer and the first film when the second film is peeled off.

The thickness of the second film is not particularly limited, and may be, for example, 10 μm to 150 μm.

< Cured object >)

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

< Printing Wiring Board >)

The printed wiring board of the present invention has a cured product obtained from the photosensitive resin composition of the present invention or the resin layer of the dry film. As a method for producing a printed wiring board of the present invention, for example, the photosensitive resin composition of the present invention is adjusted to a viscosity suitable for a coating method by using the above-mentioned organic solvent, and is coated on a substrate by a method such as a dip coating method, a flow coating method, a roll coating method, a bar coating method, a screen printing method, or a curtain coating method, and then the organic solvent contained in the composition is volatilized and dried (pre-dried) at a temperature of 60 to 100 ℃. In the case of the dry film, the resin layer is formed on the substrate by bonding the dry film to the substrate in such a manner that the resin layer contacts the substrate by a laminator or the like and then peeling the first film.

As the base material, a base material using a paper phenol resin, a paper epoxy resin, a glass cloth epoxy resin, a glass polyimide, a glass cloth/nonwoven fabric epoxy resin, a glass cloth/paper epoxy resin, a synthetic fiber epoxy resin, a fluororesin-polyethylene-polyphenylene ether, a polyphenylene ether-cyanate ester, or other materials such as a copper-clad laminate for a high frequency circuit, a copper-clad laminate of all grades (FR-4, etc.), a metal substrate, a polyimide film, a polyethylene terephthalate film, a polyethylene naphthalate (PEN) film, a glass substrate, a ceramic substrate, a wafer sheet, or the like is used in addition to a printed wiring board or a flexible printed wiring board in which a circuit is formed in advance of copper, etc.

In the case of the dry film form, it is preferable to attach the dry film to the substrate under pressure and heat using a vacuum laminator or the like. When a circuit-forming substrate is used by using such a vacuum laminator, the dry film adheres to the circuit substrate even if there are irregularities on the surface of the circuit substrate, and therefore, no air bubbles are mixed, and the hole filling property of the concave portion on the surface of the substrate is improved. The pressurizing condition is preferably about 0.1 to 2.0MPa, and the heating condition is preferably 40 to 120 ℃.

When the photosensitive resin composition of the present invention contains an organic solvent, it is preferable that the photosensitive resin composition is applied to the surface of the substrate and then dried by evaporation. The volatilization drying can be performed using a hot air circulation type drying furnace, an IR furnace, a hot plate, a convection oven, or the like (a device using a heat source of an air heating system of standby steam, a method of bringing hot air in a dryer into convection contact, or a method of spraying the hot air from a nozzle onto a substrate).

After forming a resin layer on a substrate, a photomask having a predetermined pattern is formed, and the resin layer is selectively exposed to active energy rays, and the unexposed portion is developed with a dilute aqueous alkali solution (for example, 0.3 to 3 mass% aqueous sodium carbonate solution) to form a pattern of a cured product. In the case of a dry film, after exposure, the first film is peeled from the dry film and developed, thereby forming a patterned cured product on the substrate. In the case of the dry film form, the first film may be peeled from the dry film before exposure, and the exposed resin layer may be exposed and developed as long as the characteristics are not impaired. Further, the cured product is heated and cured (for example, 100 to 220 ℃) after irradiation with active energy rays, or heated and cured after irradiation with active energy rays, or cured by heating only (main curing) to thereby form a cured coating film excellent in various properties such as adhesion and hardness.

As the exposure device for irradiation of active energy rays, any device may be used as long as it is 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 ultraviolet rays in the range of 350 to 450nm, and further, a direct drawing device (for example, a laser direct imaging device that directly draws an image with laser light using CAD data from a computer) may be used. The light source or the laser source of the direct-scanning machine may be a light source having a maximum wavelength of 350 to 450 nm. The exposure amount for forming an image varies depending on the film thickness and the like, and can be generally 10 to 1000mJ/cm ², preferably 20 to 800mJ/cm ².

As the developing method, a dipping method, a spraying method, a brushing method, or the like can be used, and as the developing solution, an aqueous alkali solution of potassium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, or the like can be used.

After forming the cured coating film on the base material as described above, components such as electronic components are mounted on the base material by solder reflow treatment. The solder reflow process can be performed by a currently known method. The solder reflow is usually performed at 245 to 260 ℃ for 5 to 10 seconds, for example.

The photosensitive resin composition or dry film of the present invention is suitably used for manufacturing electronic components such as printed wiring boards, and more preferably for forming permanent coatings. In this case, a cured product is formed by the above method or the like using the photosensitive resin composition or the dry film of the present invention. When the resin layer of the photosensitive resin composition or dry film of the present invention is insulating, it is preferably used for forming a solder resist, a coverlay or an interlayer insulating layer. In particular, the composition can be suitably used for the purpose of forming a permanent coating film such as a solder resist used for a package substrate. The photosensitive resin composition of the present invention can also be used for forming a solder dam.

Examples

The present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples. In the following, unless otherwise specified, "parts" and "%" are both based on mass.

Synthesis example 1 (Synthesis of alkali-soluble resin A) >)

A novolak-type cresol resin (trade name: shonol CRG951, manufactured by Aike Co., ltd.) (OH equivalent: 119.4) 119.4 parts by mass, potassium hydroxide 1.19 parts by mass, and toluene 119.4 parts by mass were introduced into an autoclave equipped with a thermometer, a nitrogen introducing device, an alkylene oxide introducing device, and a stirring device, and nitrogen substitution was performed in the system while stirring, and the temperature was raised. Then, 63.8 parts by mass of propylene oxide was gradually dropped, and the mixture was reacted at 125 to 132℃for 16 hours under conditions of 0 to 4.8kg/cm ². Then, the reaction solution was cooled to room temperature, and 1.56 parts by mass of 89% phosphoric acid was added to the reaction solution and mixed with potassium hydroxide to obtain a propylene oxide reaction solution [ solid component ] of a novolak-type cresol resin: 62.1%; hydroxyl value: 182.2mgKOH/g (307.9 g/eq.) ]. The propylene oxide reaction solution was obtained by adding 1.08 moles of propylene oxide to 1 equivalent of phenolic hydroxyl groups on average.

The propylene oxide reaction solution 293.0 parts by mass, acrylic acid 43.2 parts by mass, methanesulfonic acid 11.53 parts by mass, methyl hydroquinone 0.18 parts by mass, and toluene 252.9 parts by mass of the obtained novolak-type cresol resin were introduced into a reactor having a stirrer, a thermometer, and an air blowing tube, and reacted at 110℃for 12 hours while blowing air at a rate of 10 mL/min and stirring. 12.6 parts by mass of water produced by the reaction was distilled off as an azeotropic mixture with toluene. Then, the reaction solution was cooled to room temperature, and 35.35 parts by mass of a 15% aqueous sodium hydroxide solution was used to neutralize the reaction solution, followed by washing with water. Next, the resultant was distilled off using 118.1 parts by mass of diethylene glycol monoethyl ether acetate in place of toluene by an evaporator to obtain a novolak-type acrylic resin solution.

Then, to a reactor having a stirrer, a thermometer and an air blowing tube, 332.5 parts by mass of the obtained novolak-type acrylic resin solution and 1.22 parts by mass of triphenylphosphine were introduced, and 60.8 parts by mass of tetrahydrophthalic anhydride was gradually added while blowing air at a rate of 10 mL/min and stirring, reacted at 95 to 101℃for 6 hours, cooled, and taken out.

In the manner described above, a solution of the alkali-soluble resin A (solid content: 65% by mass, acid value of the solid content: 87.7 mgKOH/g) was obtained.

< Formulation of silica >

[ Silica 1]

To 30g of propylene glycol monomethyl ether acetate (PMA) as a solvent, 70g of spherical silica (SFP-30M, manufactured by Denka Company Limited) having an average particle diameter of 0.6 μm was added and stirred to prepare a pre-dispersion. Next, 0.8g of methacryloxypropyl trimethoxysilane (KBM-503, manufactured by Xinyue chemical Co., ltd.) and 0.1g of methyltrimethoxysilane (KBM-13, manufactured by Xinyue chemical Co., ltd.) were added to the pre-dispersion, and the mixture was stirred at 50℃to obtain a silica slurry (solid content of silica: 70 mass%) surface-treated with the two silane coupling agents.

[ Silica 2]

To 30g of propylene glycol monomethyl ether acetate (PMA) as a solvent, 70g of spherical silica (SFP-30M, manufactured by Denka Company Limited) having an average particle diameter of 0.6 μm was added and stirred to prepare a pre-dispersion. Next, 0.1g of methacryloxypropyl trimethoxysilane (KBM-503, manufactured by Xinyue chemical Co., ltd.) and 0.8g of methyltrimethoxysilane (KBM-13, manufactured by Xinyue chemical Co., ltd.) were added to the pre-dispersion, and the mixture was stirred at 50℃to obtain a silica slurry (solid content of silica: 70 mass%) surface-treated with the two silane coupling agents.

[ Silica 3]

To 30g of propylene glycol monomethyl ether acetate (PMA) as a solvent, 70g of spherical silica (SFP-30M, manufactured by Denka Company Limited) having an average particle diameter of 0.6 μm was added and stirred to prepare a pre-dispersion. Next, 3.0g of methacryloxypropyl trimethoxysilane (KBM-503, manufactured by Xinyue chemical industries Co., ltd.) was added to the pre-dispersion, and the mixture was stirred at 50℃to obtain a silica slurry (solid content of silica: 70 mass%) surface-treated with only 1 silane coupling agent.

[ Silica 4]

To 30g of propylene glycol monomethyl ether acetate (PMA) as a solvent, 70g of spherical silica (SFP-30M, manufactured by Denka Company Limited) having an average particle diameter of 0.6 μm was added and stirred to obtain a silica slurry (solid content of silica: 70 mass%) which was not subjected to surface treatment.

Preparation of photosensitive resin composition

The components described in table 1 below were mixed at room temperature using a three-roll mill, and each photosensitive resin composition described in the table was obtained. The numerical values in the table represent parts by mass (including the mass of the solvent).

The components 1 to 6 in table 1 below are as follows.

*1: An acylphosphine oxide-based photopolymerization initiator (2, 4, 6-trimethylbenzoyl diphenyl phosphine oxide).

*2: Dipentaerythritol hexaacrylate.

*3: Dicyandiamide.

*4: Phenol novolac type epoxy resin (DIC corporation).

*5: Phenol novolac type epoxy resin (diethylene glycol monoethyl ether acetate diluted solution, solid content 75 mass%) manufactured by DIC corporation.

*6: Biphenyl/phenol novolac type epoxy resin (manufactured by japan chemical company, ltd.).

< Evaluation of storage stability >

After each photosensitive resin composition was prepared as described above, it was immediately coated on the surface of a polyethylene terephthalate film (T-60, manufactured by Toli Co., ltd., thickness: 38 μm) using a coater, and dried at 80℃for 10 minutes to prepare a dry film.

After each of the prepared photosensitive resin compositions was left for one week in a room temperature environment, a dry film was produced in the same manner as described above.

Next, a dry film was bonded to a printed wiring board pretreated with CZ-8100 (MEC composite ltd.) manufactured by mek corporation) using a vacuum laminator (CVP-600, manufactured by Nikko materials co., ltd.), to form a resin layer on the board. The resin layer side of the substrate was subjected to pattern exposure with an optimal exposure amount using an exposure apparatus equipped with a high-pressure mercury lamp (short arc lamp) via a step exposure meter, and developed with a 1 mass% sodium carbonate aqueous solution at 30 ℃ for 60 seconds under a jet pressure of 0.2 MPa. The obtained substrate was irradiated with ultraviolet rays under a cumulative exposure of 1000mJ/cm ² by a UV conveyor oven, and then heated at 170℃for 60 minutes to cure the resin layer, thereby producing an evaluation substrate.

The gloss of the pattern of the step exposure table of the evaluation substrate obtained as described above was compared, and the storage stability was evaluated based on the following evaluation criteria.

O: the sensitivity variation is within +1.

X: the sensitivity is raised by more than 2 levels.

The evaluation results are shown in table 1 below.

Evaluation of film Properties (elastic modulus)

The dry films produced as described above were bonded to a copper-filled substrate with the glossy side of the copper foil facing upward, and a resin layer was produced on the copper foil by using a vacuum laminator so that the resin layer was in contact with the substrate.

After the resin layer was exposed to light at the optimum exposure amount using an exposure apparatus equipped with a silver short arc lamp, the resin layer was cured by ultraviolet irradiation with a UV conveyor oven under a cumulative exposure amount of 1000mJ/cm ², and then heated at 170 ℃ for 60 minutes, thereby forming a cured film. Then, the cured film was peeled off from the copper foil, and then the sample was cut out according to the measurement size. The sample was supplied to a universal tester (autograph) (AG-X, manufactured by Shimadzu corporation) to measure the elastic modulus. The evaluation criteria are as follows.

And (3) the following materials: the elastic modulus is 8GPa or more under the condition of room temperature.

And (2) the following steps: the elastic modulus is 6 to 8Gpa under the condition of room temperature.

X: the modulus of elasticity is less than 6GPa at room temperature.

The evaluation results are shown in table 1 below.

TABLE 1

As is clear from table 1, the photosensitive resin compositions (examples 1 to 3) containing silica, which was surface-treated with both the silane coupling agent having no reactive functional group and the silane coupling agent having a specific reactive functional group, had good film physical properties such as elastic modulus and also had excellent storage stability.

In addition, it was found that, among the photosensitive resin compositions (examples 1 to 3) containing silica surface-treated with two kinds of coupling agents, the photosensitive resin composition (example 1) containing silica having a larger amount of coating with the silane coupling agent having a reactive functional group than the amount of coating with the silane coupling agent having no reactive functional group has a more excellent elastic modulus than the photosensitive resin composition (example 2) containing silica having a smaller amount of coating with the silane coupling agent having a reactive functional group than the amount of coating with the silane coupling agent having no reactive functional group. Further, it was found that the photosensitive resin composition (example 1) containing the silica surface-treated with the two coupling agents at a ratio of 50 mass% or more had a more excellent elastic modulus than the photosensitive resin composition (example 3) containing the silica surface-treated with the two coupling agents at a ratio of less than 50 mass%.

On the other hand, it was found that the photosensitive resin composition containing silica surface-treated with only the silane coupling agent having a specific reactive functional group as silica (comparative example 1) and the photosensitive resin composition containing silica surface-untreated (comparative example 2) were not capable of achieving both coating film physical properties and storage stability.

Claims (8)

1. A photosensitive resin composition comprising at least (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) silica, and (D) a photopolymerizable monomer, characterized in that,

The silica (C) is a silica surface-treated with two silane coupling agents, a silane coupling agent having no reactive functional group and a silane coupling agent having at least one reactive functional group selected from the group consisting of vinyl, (meth) acryl and styryl.

2. The photosensitive resin composition according to claim 1, wherein,

The amount of the silica coated with the silane coupling agent having the reactive functional group is larger than the amount of the silica coated with the silane coupling agent having no reactive functional group.

3. The photosensitive resin composition according to claim 2, wherein,

In the (C) silica, the ratio of the amount coated by the silane coupling agent having the reactive functional group to the amount coated by the silane coupling agent having no reactive functional group is 2 on a mass basis: 1 to 10:1.

4. The photosensitive resin composition according to claim 1, wherein,

The photosensitive resin composition contains the (C) silica in a proportion of 50 to 90 mass% relative to the total solid content in the photosensitive resin composition.

5. The photosensitive resin composition according to claim 1, wherein,

The photosensitive resin composition further comprises (E) a thermosetting component.

6. A dry film, wherein,

The dry film has:

a first film; and

A resin layer obtained by applying the photosensitive resin composition according to claim 1 to one surface of the first film and drying the applied film.

7. A cured product of the above-mentioned composition, wherein,

The cured product is obtained by curing the photosensitive resin composition according to any one of claims 1 to 5 or the resin layer of the dry film according to claim 6.

8. A printed wiring board, wherein,

The printed wiring board having a coating film comprising the cured product according to claim 7.