KR20240054181A - Photosensitive resin composition, dry film, cured product, and printed wiring board - Google Patents

Abstract

A photosensitive resin composition is provided that suppresses the decline in coating film 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 silane having no reactive functional group. Characterized by surface treatment with two types of silane coupling agents: a coupling agent and a silane coupling agent having at least one reactive functional group selected from the group consisting of vinyl group, (meth)acryloyl group, and styryl group. do.

Description

Photosensitive resin composition, dry film, cured product, and printed wiring board {PHOTOSENSITIVE RESIN COMPOSITION, DRY FILM, CURED PRODUCT, AND PRINTED WIRING BOARD}

The present invention relates to a photosensitive resin composition, and more specifically, to a photosensitive resin composition that can be suitably used for forming an insulating layer such as solder resist, a dry film using the photosensitive resin composition, a cured product of the photosensitive resin composition or dry film, and It relates to printed wiring boards using these hardened materials.

Generally, in printed wiring boards used in electronic devices, etc., a circuit pattern is formed to prevent solder from adhering to unnecessary parts of the printed wiring board during processes such as solder reflow when mounting electronic components on the printed wiring board. A solder resist layer is formed in areas excluding connection holes on the substrate. The solder resist layer is mainly formed by so-called photo solder resist, which involves applying a photosensitive resin composition to a substrate, drying it, forming a pattern through exposure and development, and then curing the patterned resin by heating or irradiating light. It is written as . In addition, it has been proposed to form a solder resist layer using a photosensitive dry film instead of using the liquid photosensitive resin composition as described above.

These photosensitive resin compositions and photosensitive dry films contain an alkali-soluble photosensitive resin component to enable exposure and development, and, if necessary, other photopolymerizable monomers or thermosetting components such as epoxy in consideration of heat resistance and substrate adhesion. This is included. Additionally, in order to reduce the coefficient of linear expansion and suppress peeling of the solder resist layer or warping of the substrate, an inorganic filler may be blended in the photosensitive resin composition (Japanese Patent Application Laid-Open No. 2001-72834, etc.).

Among inorganic fillers, spherical silica is especially excellent in fillability and has a low thermal expansion coefficient, so it is widely used to improve the properties of solder resist. However, as the mixing amount of the inorganic filler increases, the interface between the inorganic filler and the resin increases, so there is a tendency for coating film physical properties such as elastic modulus and tensile strength to decrease. Therefore, even if it is silica, which is considered to have high filling properties, it is practiced to suppress the decline in the physical properties of the coating film by surface treating it with a silane coupling agent having a reactive functional group such as an amino group or a (meth)acryloyl group (Japanese Patent Application Publication No. Gazette No. 2018-165795, etc.).

Surface treatment of silica is performed by adding and reacting a silane coupling agent to silica, and is blended into the photosensitive resin composition as a silica slurry containing a silane coupling agent. Therefore, the silane coupling agents of the glass contained in the silica slurry cause a condensation reaction, which may react with the resin component in the photosensitive resin composition, which not only reduces storage stability but also affects the crosslinking density of the resin component. In some cases, the sensitivity of the photosensitive resin composition also decreased. Additionally, when the photosensitive resin composition is stored for a long period of time, there are cases where the components in the photosensitive resin composition react with the silane coupling agent in the glass, causing the sensitivity of the photosensitive resin composition to abnormally increase.

Therefore, the purpose of the present invention is to provide a photosensitive resin composition that suppresses the decline in coating film properties such as elastic modulus and has excellent storage stability.

The present inventors studied the above problem and found that the use of silica surface-treated with two types of silane coupling agents, one having a reactive functional group and the other silane coupling agent not having a reactive functional group, resulted in a decrease in the physical properties of the coating film. It was discovered that a photosensitive resin composition with excellent storage stability can be obtained while suppressing . The present invention is based on this knowledge. That is, 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,

The (C) silica is two types: 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)acryloyl group, and styryl group. A photosensitive resin composition, characterized in that the surface has been treated with a silane coupling agent.

[2] Among the silane coupling agents coated on the surface of the (C) silica, the amount covered by the silane coupling agent having the above-mentioned reactive functional group is greater than the amount covered by the silane coupling agent not having the above-mentioned reactive functional group. Many of the photosensitive resin compositions described in [1].

[3] In the silica (C), 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 not having the reactive functional group is 2:1 to 10 on a mass basis. :1 person, the photosensitive resin composition described in [2].

[4] The photosensitive resin composition according to [1], wherein the (C) silica is contained in a ratio of 50 to 90% by mass based on the total solid content in the photosensitive resin composition.

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

[6] A dry film comprising a first film and a resin layer obtained by applying and drying the photosensitive resin composition according to [1] on one side of the first 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 provided with a film made of the cured material described in [7].

According to the present invention, by using silica surface-treated with two specific types of silane coupling agents, it is possible to realize a photosensitive resin composition that suppresses the decline in coating film properties such as elastic modulus and has excellent storage stability.

[Photosensitive resin composition]

The photosensitive resin composition according to the present invention contains at least (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) silica, and (D) a photopolymerizable monomer. Hereinafter, each component constituting the photosensitive resin composition is explained. In addition, in this specification, (meth)acrylic is used as a general term for both acrylic and methacrylic. In addition, (meth)acryloyl shall be used as a general term for both acryloyl and methacryloyl. In addition, (meth)acrylate is used as a general term for acrylates, methacrylates, and mixtures thereof.

<(A) Alkali soluble resin>

(A) alkali-soluble resin contained in the photosensitive resin composition according to the present invention may be any alkali-soluble resin, and a known and commonly used resin may be used. Alkali-soluble resin can be used individually or in combination of two or more types. Examples include water-soluble resins such as carboxyl group-containing resins and phenolic hydroxyl group-containing resins. Among these, since they are excellent in developability, carboxyl group-containing resins and phenolic hydroxyl group-containing resins are preferable, and carboxyl group-containing resins are more preferable. By containing a carboxyl group, the alkali-soluble resin can be made alkali-developable. Furthermore, from the viewpoint of photosensitivity, it is preferable to have an ethylenically unsaturated double bond in the molecule in addition to the carboxyl group, but only a carboxyl group-containing resin that does not have an ethylenically unsaturated double bond may be used. When the carboxyl group-containing resin does not have an ethylenically unsaturated double bond, it is necessary to use a photopolymerizable monomer together to make the composition photocurable. As the ethylenically unsaturated double bond, those derived from acrylic acid or methacrylic acid or derivatives thereof are preferable.

Specific examples of the carboxyl group-containing resin include the following compounds (which may be either oligomers or polymers). In addition, in this specification, (meth)acrylate is a general term for acrylates, methacrylates, and mixtures thereof, and the same applies to other similar expressions.

(1) Carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid such as (meth)acrylic acid and an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth)acrylate, and isobutylene.

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

(3) Diisocyanate and bifunctional epoxy resins such as bisphenol A-type epoxy resin, hydrogenated bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, bixylenol-type epoxy resin, and biphenol-type epoxy resin. Photosensitive urethane resin containing a carboxyl group by polyaddition reaction of a partial acid anhydride modification of the reaction product of a monocarboxylic acid compound having an ethylenically unsaturated double bond such as (meth)acrylic acid, a dialcohol compound containing a carboxyl group, and a diol compound.

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

(5) During the synthesis of the resin of (2) or (3) above, an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate, etc., has one isocyanate group and one or more (meth)acryloyl groups in the molecule. A photosensitive urethane resin containing a carboxyl group whose ends are (meth)acrylated by adding a compound.

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

(7) A photosensitive resin containing a carboxyl group obtained by reacting (meth)acrylic acid with a polyfunctional epoxy resin in which the hydroxyl group of the difunctional (solid) epoxy resin is further epoxidized with epichlorohydrin, and adding a dibasic acid anhydride to the resulting hydroxyl group.

(8) Dicarboxylic acids such as adipic acid, phthalic acid, and hexahydrophthalic acid are reacted with difunctional oxetane resin, and the primary hydroxyl group generated is replaced with dibasic acids such as phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. A polyester resin containing a carboxyl group to which an acid anhydride has been added.

(9) Epoxy compounds having multiple epoxy groups in one molecule, compounds having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol, and unsaturated compounds such as (meth)acrylic acid. Contains a carboxyl group obtained by reacting a group-containing monocarboxylic acid and reacting the alcoholic hydroxyl group of the resulting reaction product with a polybasic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and adipic acid. Photosensitive resin.

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

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

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

These carboxyl group-containing resins can be used without being limited to those listed above. One type may be used individually, or multiple types may be mixed and used. Among the above, carboxyl group-containing resins synthesized using a compound having a phenolic hydroxyl group, such as carboxyl group-containing resins (10) and (11), as starting materials, can be suitably used because they have excellent HAST resistance and PCT resistance.

The acid value of the carboxyl group-containing resin is preferably 40 to 150 mgKOH/g. When the acid value of the carboxyl group-containing resin is 40 mgKOH/g or more, the alkaline phenomenon becomes good. Additionally, by setting the acid value to 150 mgKOH/g or less, it is possible to easily draw a good resist pattern. More preferably, it is 50 to 130 mgKOH/g.

The weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, but is generally preferably 2,000 to 150,000. By setting the weight average molecular weight to 2,000 or more, tack-free performance and resolution can be improved. Additionally, by setting the weight average molecular weight to 150,000 or less, developability and storage stability can be improved. More preferably, it is 5,000 to 15,000. Additionally, the weight average molecular weight can be measured by gel permeation chromatography (GPC).

The compounding amount of the above-mentioned (A) alkali-soluble resin is preferably 10 to 50% by mass in terms of solid content in the photosensitive resin composition. The coating film strength can be improved by setting it to 10% by mass or more. Additionally, by setting it to 50% by mass or less, the viscosity becomes appropriate and printability improves. More preferably, it is 10 to 30 mass%.

<(B) Photopolymerization initiator>

The photosensitive resin composition according to the present invention contains a photopolymerization initiator (B) in order to photopolymerize the alkali-soluble resin (A) described above and the photopolymerizable monomer (D) described later. As the photopolymerization initiator, known ones can be used, for example, 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-morpholinyl)phenyl]- α-aminoacetophenone-based photopolymerization initiators such as 1-butanone and N,N-dimethylaminoacetophenone: 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}- Hydroxyacetophenone-based photopolymerization initiators such as 2-methyl-propan-1-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one; Bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propyl Phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl) )-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)-phenyl Phosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine Acylphosphine oxide-based photopolymerization initiators such as pin oxide, pivaloylphenylphosphinic acid isopropyl ester, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; Benzoin-based photopolymerization initiators such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; Benzoin alkyl ether-based photopolymerization initiator; Benzophenone photopolymerization initiators such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bisdiethylaminobenzophenone; Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl- Acetophenone-based photopolymerization initiator of 1-[4-(methylthio)phenyl]-2-morpholino-1-phmorpholino; Thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-di Thioxanthone-based photopolymerization initiators such as isopropylthioxanthone; Anthraquinone-based photopolymerization such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone initiator; Ketal-based photopolymerization initiators such as acetophenone dimethyl ketal and benzyl dimethyl ketal; Benzoic acid ester-based photopolymerization initiators such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethylbenzoate, and p-dimethylbenzoic acid ethyl ester; 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H -carbazol-3-yl]-, 1-(O-acetyloxime), and other oxime ester photopolymerization initiators; Bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)- Titanocene-based photopolymerization initiators such as bis[2,6-difluoro-3-(2-(1-phil-1-yl)ethyl)phenyl]titanium; etc. can be mentioned. These photopolymerization initiators may be used individually by 1 type, or may be used in combination of 2 or more types.

Commercially available α-aminoacetophenone photopolymerization initiators include Omnirad 907, 369, 369E, and 379 manufactured by IGM Resins.

Commercially available acylphosphine oxide photopolymerization initiators include Omnirad 819 manufactured by IGM Resins.

Commercially available titanocene-based photopolymerization initiators include JMT-784 manufactured by Yueyang Kimoutain Sci-tech Co., Ltd. and GR-FMT manufactured by Hubei Guren Science and Technology Co., Ltd.

Additionally, a photopolymerization initiator having two oxime ester groups in the molecule can also be suitably used, and specifically, an oxime ester compound having a carbazole structure represented by the following general formula (I) can be mentioned.

In the above formula, is substituted by an alkylamino or dialkylamino group having an alkyl group), a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group or dialkyl having an alkyl group having 1 to 8 carbon atoms) is substituted by an amino group), and Y and Z are each a hydrogen atom, an alkyl group with 1 to 17 carbon atoms, an alkoxy group with 1 to 8 carbon atoms, a halogen group, a phenyl group, and a phenyl group (an alkyl group with 1 to 17 carbon atoms, 1 carbon atom) Substituted by an alkylamino or dialkylamino group having an alkyl group having 1 to 8 carbon atoms, an amino group, an alkyl group having 1 to 8 carbon atoms), a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, a carbon number is substituted by an alkylamino group or dialkylamino group having 1 to 8 alkyl groups), anthryl group, pyridyl group, benzofuryl group, benzothienyl group, and Ar is alkylene or vinylene having 1 to 10 carbon atoms. , phenylene, biphenylene, pyridylene, naphthylene, thiophene, anthrylene, thienylene, furylene, 2,5-pyrrole-diyl, 4,4'-stilbene-diyl, 4,2'- Represents styrene-diyl, and n is an integer of 0 or 1.

In _particular , in the _above formula, is desirable.

In addition to the photopolymerization initiators described above, benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds and xanthone compounds can be used as photopolymerization initiators.

However, it is preferable to use them as a photopolymerization initiation auxiliary or sensitizer in combination with the above-described photopolymerization initiator rather than using them alone as a photopolymerization initiator.

Among the above, from the viewpoint of deep hardenability, thioxanthone compounds and tertiary amine compounds are preferable, and thioxanthone compounds are more preferable. Additionally, two or more types of the above compounds may be used in combination.

The compounding amount of the photopolymerization initiator (B) 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, with respect to 100 parts by mass of the alkali-soluble resin (A). Thereby, the hardenability of the core part can be improved.

In addition, when the photosensitive resin composition contains the above-described benzoin compound or the like as a photopolymerization initiation auxiliary agent or the like, the compounding amount is preferably 0.01 to 10 parts by mass, in terms of solid content, with respect to 100 parts by mass of the alkali-soluble resin (A). , it is more preferable that it is 0.1 to 5 parts by mass. Thereby, the hardenability of the core part can be improved.

<(C) Silica>

The photosensitive resin composition according to the present invention contains (C) silica. (C) Silica used in the present invention is a silane coupling agent having no reactive functional group, and a silane couple having at least one type of reactive functional group selected from the group consisting of a vinyl group, (meth)acryloyl group, and styryl group. It is surface treated with two types of silane coupling agents. In this way, by using silica surface-treated with two types of silane coupling agents, a silane coupling agent without a reactive functional group and a silane coupling agent with a specific reactive functional group, a decrease in the physical properties of the coating film such as elastic modulus is suppressed, A photosensitive resin composition with excellent storage stability can be used. Although the reason for this is not clear, it can be estimated as follows.

That is, from the viewpoint of improving coating film properties such as elastic modulus, it is preferable that the surface of the silica to be blended has a predetermined reactive functional group. However, as described above, the silane coupling agent having a reactive functional group is a silane coupling agent of the glass. When it exists as a ring agent in the photosensitive resin composition, silane coupling agents may react with each other or the silane coupling agent may react with other components in the photosensitive resin composition, and storage stability deteriorates. Therefore, if the amount of the silane coupling agent having a reactive functional group used when surface treating silica is reduced, the storage stability is improved, but the hydrophilicity of the surface-treated silica becomes stronger, causing problems such as aggregation. In the present invention, among the silane coupling agents that cover silica, a silane coupling agent having a reactive functional group is used to improve the physical properties of the coating film, and by using a silane coupling agent without a reactive functional group in combination, hydrophobicity is imparted to the silica to prevent aggregation, etc. It can be assumed that by suppressing this, a photosensitive resin composition with excellent storage stability can be obtained.

Silane coupling agents that do not have a reactive functional group include compounds containing a Si element having an alkoxysilyl group or a silanol group, for example, methyltrimethoxysilane, ethyltrimethoxysilane, and n-propyltrimethoxy. Silane, isopropyltrimethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, n-pentyltrimethoxysilane, cyclopentyltrimethoxysilane, n-hexyltrimethoxysilane, cyclohexyltri Methoxysilane, n-octyltrimethoxysilane, isooctyltrimethoxysilane, n-decyltrimethoxysilane, n-dodecyltrimethoxysilane, n-tetradecyltrimethoxysilane, n-hexadecyltrime Toxysilane, n-octadecyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, 7-octenyltrimethoxysilane, phenyltrimethoxysilane, benzyltrimethoxysilane, 1-naphthyltrime Toxysilane, methyltriethoxysilane, ethyltriethoxysilane, n-propyltriethoxysilane, isopropyltriethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, n-pentyltriethoxy Silane, cyclopentyltriethoxysilane, n-hexyltriethoxysilane, cyclohexyltriethoxysilane, n-octyltriethoxysilane, isooctyltriethoxysilane, n-decyltriethoxysilane, n-dodecyl Triethoxysilane, n-tetradecyltriethoxysilane, n-hexadecyltriethoxysilane, n-octadecyltriethoxysilane, etc. are mentioned. These silane coupling agents that do not have a reactive functional group may be used individually, or may be used in combination of two or more types. Among these, methyltrimethoxysilane and ethyltrimethoxysilane can be preferably used.

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

As vinyl group-containing silane coupling agents, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltris(2-methoxyethoxy)silane, vinylmethyldimethoxysilane, and octenyltrimethoxysilane. , allyltrimethoxysilane, etc.

In addition, as a (meth)acryloyl group-containing silane coupling agent, 1,3-bis(acryloyloxymethyl)-1,1,3,3-tetramethyldisilazane, 1,3-bis(methacryloyloxymethyl)-1,1,3,3-tetramethyldisilazane, 1oxymethyl)-1,1,3,3-tetramethyldisilazane, 1,3-bis(γ-acryloyloxypropyl)-1,1,3,3-tetramethyldisilazane, 1, 3-bis(γ-methacryloyloxypropyl)-1,1,3,3-tetramethyldisilazane, acryloyloxymethylmethyltrisilazane, methacryloyloxymethylmethyltrisilazane, acrylic Loyloxymethylmethyltetrasilazane, methacryloyloxymethylmethyltetrasilazane, acryloyloxymethylmethylpolysilazane, methacryloyloxymethylmethylpolysilazane, 3-acryloyloxypropylmethyltri Silazane, 3-methacryloyloxypropylmethyltrisilazane, 3-acryloyloxypropylmethyltetrasilazane, 3-methacryloyloxypropylmethyltetrasilazane, 3-acryloyloxypropylmethylpoly Silazane, 3-methacryloyloxypropylmethylpolysilazane, acryloyloxymethylpolysilazane, methacryloyloxymethylpolysilazane, 3-acryloyloxypropylpolysilazane, 3-methacryl Royloxypropyl polysilazane, etc. can be mentioned.

Additionally, examples of the styryl group-containing silane coupling agent include p-styryltrimethoxysilane.

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

(C) Surface treatment of silica is preferably performed by adding a silane coupling agent at a ratio of 0.5 to 10 parts by mass, more preferably 0.5 to 2.0 parts by mass, based on 100 parts by mass of silica. Surface treatment of silica can be performed by preparing a dispersion in which silica is dispersed in an appropriate solvent, adding a predetermined amount of a silane coupling agent to the silica dispersion, and stirring. In order to promote the surface treatment reaction, stirring may be performed in a heating environment at a temperature of 50 to 100°C.

(C) Among the silane coupling agents coated on the silica surface, the amount of silica coated with the silane coupling agent having the reactive functional group is preferably greater than the amount coated with the silane coupling agent not having the reactive functional group. . As for the silane having the above coverage ratio, for example, by adjusting the proton mixing amount when adding the silane coupling agent to the silica dispersion, the silane coupling agent having a reactive functional group is more common than the silane coupling agent having no reactive functional group. It can be obtained by performing surface treatment of silica so that it becomes clear. In particular, it is preferable that the silica has a ratio of the amount coated by the silane coupling agent having a reactive functional group to the amount coated by the silane coupling agent not having a reactive functional group of 2:1 to 10:1 on a mass basis. Silica having such a coverage ratio is, for example, prepared by using a silane coupling agent containing a silane coupling agent having a reactive functional group and a silane coupling agent not having a reactive functional group in a mass ratio of 2:1 to 10:1. It can be obtained through surface treatment. The presence or absence of surface treatment can be confirmed by quantifying the unreacted coupling agent in the silica slurry by LC-MS. Additionally, approximately 60 to 90% of the added silane coupling agent is covered.

In addition, compared to the case where silica and silane coupling agent are added individually at the same time, a higher effect is obtained when surface-treated silica is used.

As silica to be surface treated, conventionally known silica can be used without limitation, and may be amorphous, crystalline, or a mixture thereof. In particular, amorphous (fused) silica is preferred.

From the viewpoint of dispersibility and the like, silica preferably has an average particle diameter (D50) of 0.1 to 1.0 μm, and more preferably 0.4 to 0.8 μm. In addition, the average particle size means the particle size at 50% of volume accumulation obtained using a laser diffraction scattering type particle size distribution measurement method. In addition, the average particle diameter of silica shall refer to the value measured as above for silica before preparing the photosensitive resin composition (preliminary stirring, kneading).

The compounding amount of silica in the photosensitive resin composition is preferably 50 to 90% by mass, more preferably 60 to 90% by mass, based on the total solid content in the photosensitive resin composition from the viewpoint of coating film physical properties and the like.

<Inorganic filler>

The photosensitive resin composition according to the present invention may contain other inorganic fillers in addition to the (C) silica described above. Known inorganic fillers can be used, including talc, mica, aluminum oxide, calcium oxide, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, fly ash, dehydrated sludge, kaolin, clay, calcium hydroxide, aluminum hydroxide, and magnesium hydroxide. , hydrotalcite, aluminum silicate, magnesium silicate, calcium silicate, wollastonite, potassium titanate, magnesium sulfate, calcium sulfate, magnesium phosphate, sepiolite, zonolite, boron nitride, aluminum borate, silica balloon, glass flake, Glass balloon, steel slag, copper, iron, iron oxide, sendust, alnico magnet, various ferrite and other magnetic components, cement, glass powder, Neuburg silica, diatomaceous earth, antimony trioxide, magnesium oxysulfate, hydrated aluminum, hydrated gypsum, Alum and barium sulfate can be mentioned. These inorganic fillers may be used individually or in combination of two or more types. Additionally, (C) inorganic fillers other than silica may also be surface treated similarly to silica.

From the viewpoint of dispersibility, etc., the inorganic filler other than (C) silica described above preferably has an average particle diameter (D50) of 0.1 to 100 μm, and more preferably 0.1 to 50 μm. Additionally, average particle size has the same meaning as the above definition.

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

<Photopolymerizable monomer>

The photosensitive resin composition of the present invention contains (D) a photopolymerizable monomer. A photopolymerizable monomer is a monomer having an ethylenically unsaturated double bond. Examples of such photopolymerizable monomers include commonly known polyester (meth)acrylate, polyether (meth)acrylate, urethane (meth)acrylate, carbonate (meth)acrylate, epoxy (meth)acrylate, etc. I can hear it. 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, and dipropylene glycol; Acrylamides such as N,N-dimethylacrylamide, N-methylolacrylamide, and N,N-dimethylaminopropylacrylamide; Aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate and N,N-dimethylaminopropyl acrylate; Polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, and trishydroxyethyl isocyanurate, or their alkylene oxide adducts or ε-caprolactone adducts, etc. polyacrylates; polyacrylates such as phenols such as phenoxyacrylate and bisphenol A diacrylate or alkylene oxide adducts thereof; Acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; Not limited to the above, acrylates and melamine acrylates obtained by directly acrylating polyols such as polyether polyol, polycarbonate diol, hydroxyl-terminated polybutadiene, and polyester polyol, or converting them into urethane acrylates through diisocyanate. and at least one type of methacrylate corresponding to the acrylate described above. This photopolymerizable monomer can also be used as a reactive diluent.

(D) Photopolymerizable monomers can be used individually or in combination of two or more types. The compounding amount of the photopolymerizable monomer is preferably 0.5 to 30 parts by mass in terms of solid content, based on 100 parts by mass of the alkali-soluble resin (A). When the compounding amount is 0.5 parts by mass or more, photocurability is good and pattern formation is easy to achieve in alkali development after irradiation with active energy rays. Additionally, if the mixing amount is 30 parts by mass or less, halation is unlikely to occur and good resolution is 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 thermosetting components include well-known and commonly used ones such as isocyanate compounds, blocked isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, oxetane compounds, and episulfide resins. You can. Among these, a 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 novolak-type epoxy resin, and cresol novolak. 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, etc., and these can be used alone. You may use it, or you may use it in combination of two or more types.

Commercially available epoxy resins include, for example, jER 828, 806, 807, YX8000, YX8034, and 834 manufactured by Mitsubishi Chemical Corporation, and YD-128, YDF-170, and ZX-1059 manufactured by Nittetsu Chemical & Materials Corporation. , ST-3000, EPICLON 830, 835, 840, 850, N-730A, N-695 manufactured by DIC Corporation, and RE-306 manufactured by Nippon Kayaku Corporation.

The equivalent weight 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, with respect to 1 equivalent of the carboxyl group of the carboxyl group-containing resin. By setting it to 0.5 equivalent or more, residual carboxyl groups in the cured product can be prevented, and good heat resistance, alkali resistance, electrical insulation, etc. can be obtained. In addition, by setting the above compounding amount to 2.5 equivalents or less, low molecular weight cyclic (thio)ether groups can be prevented from remaining in the dried coating film, and the strength, etc. of the cured product can be ensured.

When the photosensitive resin composition of the present invention contains a thermosetting component, it may contain a thermosetting catalyst for promoting curing of the thermosetting component. As a thermosetting catalyst, for example, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, Imidazole derivatives such as 1-cyanoethyl-2-phenylimidazole and 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; Amines such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, and 4-methyl-N,N-dimethylbenzylamine. compounds, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; Phosphorus compounds, such as triphenylphosphine, etc. are mentioned. Additionally, commercially available products include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (all brand names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Corporation, and San Afro Corporation. Examples include U-CAT 3513N (a brand name for a dimethylamine compound), DBU, DBN, and U-CAT SA 102 (all bicyclic amidine compounds and salts thereof).

It is not limited to the above-mentioned compounds, and can be any heat curing catalyst for an epoxy resin or oxetane compound, or anything that promotes the reaction between at least one type of epoxy group and oxetanyl group and a carboxyl group, either alone or in a mixture of two or more types. You may use it. Additionally, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine Azine, 2-vinyl-4,6-diamino-S-triazine·isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S-triazine·isocyanuric acid S-triazine derivatives such as adducts may be used, and preferably, these compounds that also function as adhesion imparting agents are used in combination with a thermosetting catalyst.

The thermosetting catalyst can be used individually or in combination of two or more types. From the viewpoint of the storage stability of the resin composition and the heat resistance of the cured film, the amount of the thermosetting catalyst is preferably 0.01 to 30 parts by mass, and 0.1 to 20 parts by mass in terms of solid content, per 100 parts by mass of the alkali-soluble resin (A). It is more desirable.

<Other ingredients>

In addition to the above-mentioned components, the photosensitive resin composition according to the present invention may optionally contain a colorant, an elastomer, a mercapto compound, a urethanization catalyst, a thixotropic agent, an adhesion promoter, a block copolymer, a chain transfer agent, a polymerization inhibitor, an anti-freezing agent, Antioxidants, rust inhibitors, thickeners such as organic bentonite and montmorillonite, at least one type of defoamer and leveling agent such as silicone-based, fluorine-based, and polymer-based, flame retardants such as phosphorus compounds such as phosphinate, phosphate ester derivatives, and phosphazene compounds, etc. The ingredients can be combined. These can be those known in the field of electronic materials.

You may mix|blend an organic solvent with the photosensitive resin composition of this invention from the viewpoint of ease of preparation and applicability. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; Aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; Cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether. Glycol ethers such as acetate and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl 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 and commonly used organic solvents such as petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha can be used. These organic solvents can be used individually or in combination of two or more types.

The mixing amount of the organic solvent in the photosensitive resin composition can be appropriately changed depending on the materials constituting the photosensitive resin composition, for example, it can be 30 to 300 parts by mass in terms of solid content with respect to 100 parts by mass of the alkali-soluble resin (A). there is.

The photosensitive resin composition of the present invention may be used in the form of a dry film or may be used in liquid form. In addition, when using it as a liquid, it may be one-liquid or two-liquid or more.

<Dry film>

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

In order to produce a dry film, the photosensitive resin composition of the present invention is diluted with an organic solvent to adjust the viscosity to an appropriate viscosity, and a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, gravure coater, A film can be obtained by applying it to a uniform thickness on the first film using a spray coater or the like and drying it for 1 to 30 minutes, usually at a temperature of 50 to 130°C. There is no particular limitation on the coating film thickness, but generally, the film thickness after drying is appropriately selected from the range of 1 to 150 ㎛, preferably 5 to 60 ㎛.

As the first film, any known film can be used without particular limitation, for example, polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamideimide films, polypropylene films, and thermoplastic resins such as polystyrene films. A film consisting of can be suitably used. Among these, polyester films are preferable from the viewpoint of heat resistance, mechanical strength, handleability, etc. Additionally, a laminate of these films can also be used as the first film.

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

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

After forming a resin layer of the photosensitive resin composition of the present invention on the first film, a second peelable film is laminated on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. It is desirable to do so. The second film in the dry film according to the present invention refers to 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 is in contact with a base material such as a substrate.

As the second film that can be peeled from the resin layer, for example, polyethylene film, polytetrafluoroethylene film, polypropylene film, surface-treated paper, etc. can be used. When peeling the second film, the resin layer and the first film can be used. The adhesive force between the resin layer and the second film may be smaller than the adhesive force of .

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

<Hardened product>

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

<Printed 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 the application method using the above-mentioned organic solvent, and applied to the substrate by dip coating, flow coating, or roll coating. After application by a method such as a coating method, a bar coating method, a screen printing method, or a curtain coating method, the organic solvent contained in the composition is volatilized to dryness (tentative drying) at a temperature of 60 to 100 ° C. to form a tack-free resin layer. form Additionally, in the case of a dry film, a resin layer is formed on the substrate by bonding the resin layer onto the substrate using a laminator or the like so that it contacts the substrate, and then peeling off the first film.

As the substrate, in addition to printed wiring boards and flexible printed wiring boards with circuits formed in advance of copper or the like, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth/nonwoven epoxy, glass cloth/paper epoxy, synthetic fiber epoxy, and fluorine resin. · Materials such as copper-clad laminates for high-frequency circuits using polyethylene, polyphenylene ether, polyphenylene oxide, cyanate, etc. are used, including copper-clad laminates of all grades (FR-4, etc.), metal substrates, and polyimide films. , polyethylene terephthalate film, polyethylene naphthalate (PEN) film, glass substrate, ceramic substrate, wafer plate, etc.

When it is in the form of a dry film, bonding onto the substrate is preferably performed under pressure and heating using a vacuum laminator or the like. By using such a vacuum laminator, when using a circuit board, even if the surface of the circuit board has irregularities, the dry film adheres closely to the circuit board, so there is no mixing of air bubbles, and the hole filling ability of the concave part of the board surface is also improved. do. Pressurizing conditions are preferably about 0.1 to 2.0 MPa, and heating conditions are preferably 40 to 120°C.

When the photosensitive resin composition of the present invention contains an organic solvent, it is preferable to apply volatilization and drying after applying the photosensitive resin composition to the surface of the substrate. Volatilization drying is performed using a hot air circulation drying furnace, IR furnace, hot plate, convection oven, etc. (a method of countercurrent contact with hot air in a dryer using a heat source of steam-based air heating type, and spraying onto the substrate from a nozzle). method) can be used.

After forming a resin layer on the substrate, it is selectively exposed to active energy rays through a photomask with a predetermined pattern, and the unexposed portion is diluted in a dilute alkaline aqueous solution (for example, 0.3 to 3% by mass aqueous sodium carbonate solution). developed to form a pattern of the 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 addition, in the case of a dry film form, as long as the properties are not impaired, the first film may be peeled from the dry film before exposure, and the exposed resin layer may be exposed and developed. In addition, by irradiating the cured product with active energy rays and then heat curing (for example, 100 to 220°C), heat curing followed by irradiation with active energy rays, or final curing (main curing) only by heat curing, adhesion, A cured film with excellent properties such as hardness can be formed.

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

The developing method may be a dipping method, a shower method, a spray method, a brush method, etc., and the developing solution may be an aqueous alkaline solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, or amines. You can use it.

After forming the cured film on the substrate as described above, components such as electronic elements are mounted on the substrate by solder reflow processing. Solder reflow processing can be performed by a conventionally known method. Additionally, solder reflow is generally performed under processing conditions of, for example, 245 to 260°C for 5 to 10 seconds.

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 suitably is used to form a permanent film. At that time, the photosensitive resin composition or dry film of the present invention is used to form a cured product by the method described above. When the resin layer of the photosensitive resin composition or dry film of the present invention is insulating, it is suitably used to form a solder resist, a cover lay, or an interlayer insulating layer. In particular, it can be suitably used for forming permanent coating films such as solder resist used in package substrates. Additionally, the photosensitive resin composition according to the present invention may be used to form a solder dam.

[Example]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. In addition, in the following, “part” and “%” are all based on mass unless otherwise specified.

<Synthesis Example 1 (Synthesis of Alkali-Soluble Resin A)>

In an autoclave equipped with a thermometer, a nitrogen introduction device, an alkylene oxide introduction device, and a stirring device, 119.4 parts by mass of novolak-type cresol resin (product name "Shonol CRG951", manufactured by Aika Kogyo Co., Ltd., OH equivalent: 119.4), hydroxyl 1.19 parts by mass of potassium and 119.4 parts by mass of toluene were introduced, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised. Next, 63.8 parts by mass of propylene oxide was gradually added dropwise, and reaction was performed at 125 to 132°C and 0 to 4.8 kg/cm 2 for 16 hours. Thereafter, it was cooled to room temperature, and potassium hydroxide was neutralized while adding and mixing 1.56 parts by mass of 89% phosphoric acid to this reaction solution to form a propylene oxide reaction solution of novolak-type cresol resin [solid content: 62.1%; Hydroxyl value: 182.2mgKOH/g (307.9g/eq.)] was obtained. This propylene oxide reaction solution had an average of 1.08 moles of propylene oxide added per equivalent of phenolic hydroxyl group.

293.0 parts by mass of the obtained novolak-type cresol resin propylene oxide reaction solution, 43.2 parts by mass of acrylic acid, 11.53 parts by mass of methanesulfonic acid, 0.18 parts by mass of methylhydroquinone, and 252.9 parts by mass of toluene were introduced into a reactor equipped with a stirrer, thermometer, and air intake tube. Then, air was blown in at a rate of 10 ml/min, and the mixture was reacted at 110°C for 12 hours while stirring. 12.6 parts by mass of water produced by the reaction was distilled as an azeotropic mixture with toluene. After that, it was cooled to room temperature, and the obtained reaction solution was neutralized with 35.35 parts by mass of 15% aqueous sodium hydroxide solution and then washed with water. Thereafter, the toluene was distilled off in an evaporator while being replaced with 118.1 parts by mass of diethylene glycol monoethyl ether acetate, and a novolak-type acrylate resin solution was obtained.

Next, 332.5 parts by mass of the obtained novolak-type acrylate resin solution and 1.22 parts by mass of triphenylphosphine were introduced into a reactor equipped with a stirrer, a thermometer, and an air blowing tube, and air was blown in at a rate of 10 ml/min while stirring. , 60.8 parts by mass of tetrahydrophthalic anhydride was gradually added, reacted at 95 to 101°C for 6 hours, cooled, and then taken out.

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

<Preparation of silica>

[Silica 1]

As a solvent, 70 g of spherical silica (SFP-30M, Denka Co., Ltd., average particle size 0.6 μm) was added to 30 g of propylene glycol monomethyl ether acetate (PMA) and stirred to prepare a preliminary dispersion. Next, to this preliminary dispersion, 0.8 g of methacryloxypropyltrimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) and methyltrimethoxysilane (KBM-13, manufactured by Shin-Etsu Chemical Co., Ltd.) By adding 0.1 g (manufactured by Kogyo Co., Ltd.) and stirring at 50°C, a silica slurry (silica solid content: 70% by mass) surface-treated with two types of silane coupling agents was obtained.

[Silica 2]

As a solvent, 70 g of spherical silica (SFP-30M, Denka Co., Ltd., average particle size 0.6 μm) was added to 30 g of propylene glycol monomethyl ether acetate (PMA) and stirred to prepare a preliminary dispersion. Next, 0.1 g of methacryloxypropyltrimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) and methyltrimethoxysilane (KBM-13, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to this preliminary dispersion. 0.8 g (manufactured by Kogyo Co., Ltd.) was added and stirred at 50°C to obtain a silica slurry (silica solid content: 70% by mass) surface-treated with two types of silane coupling agents.

[Silica 3]

As a solvent, 70 g of spherical silica (SFP-30M, Denka Co., Ltd., average particle size 0.6 μm) was added to 30 g of propylene glycol monomethyl ether acetate (PMA) and stirred to prepare a preliminary dispersion. Next, 3.0 g of methacryloxypropyltrimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to this preliminary dispersion and stirred at 50°C to form a mixture using only one type of silane coupling agent. A surface-treated silica slurry (silica solid content: 70% by mass) was obtained.

[Silica 4]

As a solvent, 70 g of spherical silica (SFP-30M, Denka Co., Ltd., average particle diameter 0.6 μm) was added to 30 g of propylene glycol monomethyl ether acetate (PMA) and stirred to prepare a silica slurry without surface treatment (silica solid content: 70 mass%) was obtained.

<Preparation of photosensitive resin composition>

Each of the components shown in Table 1 below was mixed and mixed at room temperature using a three-roll mill to obtain each photosensitive resin composition shown in the same table. In addition, each numerical value in the table represents a mass part (mass including the solvent).

In addition, each component *1 to *6 in Table 1 below is as follows.

＊1: Acylphosphine oxide-based photopolymerization initiator (2,4,6-trimethylbenzoyldiphenylphosphine oxide)

＊2: Dipentaerythritol hexaacrylate

＊3: Dicyandiamide

*4: Phenol novolac type epoxy resin (manufactured by DIC Corporation)

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

*6: Biphenyl/phenol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.)

<Evaluation of storage stability>

Immediately after preparing each photosensitive resin composition as described above, apply it to the surface of a polyethylene terephthalate film (T-60, Toray Co., Ltd., thickness 38㎛) using an applicator, and dry at 80°C for 10 minutes. A film was produced.

Additionally, after each prepared photosensitive resin composition was left in a room temperature environment for one week, a dry film was produced in the same manner as above.

Subsequently, the dry film was pasted onto the printed wiring board pretreated using CZ-8100 manufactured by Mack Co., Ltd. using a vacuum laminator (CVP-600, manufactured by Nikko Materials Co., Ltd.) to form water on the substrate. A stratum was formed. On the resin layer side of the substrate, using an exposure device equipped with a high-pressure mercury lamp (short arc lamp), pattern exposure is performed at the optimal exposure amount through a step tablet, and a 1% by mass aqueous sodium carbonate solution at 30°C is sprayed under the condition of a spray pressure of 0.2MPa. Development was performed for 60 seconds. The obtained substrate was irradiated with ultraviolet rays in a UV conveyor furnace under the conditions of an integrated exposure dose of 1000 mJ/cm2, and then heated at 170°C for 60 minutes to cure the resin layer, thereby forming an evaluation substrate.

The pattern gloss of the step tablet of the evaluation substrate obtained as described above was compared, and storage stability was evaluated according to the following evaluation criteria.

○: The change in sensitivity was within +1 step.

×: Sensitivity was increasing by 2 steps or more.

The evaluation results were as shown in Table 1 below.

<Evaluation of coating film physical properties (elastic modulus)>

A resin layer was produced on the copper foil by attaching the copper foil with the glossy side facing up on a solid copper substrate, and attaching each of the dry films produced above using a vacuum laminator so that the resin layer was in contact with the substrate. .

The resin layer is exposed to the optimal exposure amount described above using an exposure device equipped with a silver short arc lamp, etc., then irradiated with ultraviolet rays in a UV conveyor furnace under the condition of an integrated exposure amount of 1000 mJ/cm2, and then heated at 170°C for 60 minutes to heat the resin layer. was cured to form a cured film. Subsequently, after peeling the cured film from the copper foil, a sample was cut to the measurement size. The sample was provided to Autograph (AG-X, manufactured by Shimazu Seisakusho Co., Ltd.), and the elastic modulus was measured. The evaluation criteria were as follows.

◎: Elasticity modulus is 8GPa or more at room temperature

○: Elastic modulus is 6 to 8 GPa at room temperature

×: Elastic modulus is less than 6GPa at room temperature

The evaluation results were as shown in Table 1 below.

As is clear from Table 1, a photosensitive resin composition containing silica surface-treated with two types of silane coupling agents, a silane coupling agent having no reactive functional group and a silane coupling agent having a specific reactive functional group (Example It can be seen that 1 to 3) have good coating film physical properties such as elastic modulus, and are also excellent in storage stability.

Additionally, in the photosensitive resin composition containing silica surface-treated with two types of coupling agents (Examples 1 to 3), the amount coated with the silane coupling agent having a reactive functional group is a silane couple having no reactive functional group. In the photosensitive resin composition (Example 1) containing more silica than the amount coated with the ring agent, the amount coated with the silane coupling agent having a reactive functional group is greater than the amount coated with the silane coupling agent without a reactive functional group. It can be seen that it has an elastic modulus superior to that of the photosensitive resin composition containing less silica (Example 2). In addition, the photosensitive resin composition (Example 1) containing silica surface-treated with two types of coupling agents in a proportion of 50% by mass or more has a proportion of silica surface-treated with two types of coupling agents of less than 50% by mass. It can be seen that it has an elastic modulus superior to that of the photosensitive resin composition (Example 3) contained in .

On the other hand, a photosensitive resin composition containing silica surface-treated only with a silane coupling agent having a specific reactive functional group (Comparative Example 1), or a photosensitive resin composition using silica without surface treatment (Comparative Example 2), is a coating film. It can be seen that physical properties and storage stability cannot be reconciled.

Claims (8)

A photosensitive resin composition comprising at least (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) silica, and (D) a photopolymerizable monomer,
The (C) silica is two types: 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)acryloyl group, and styryl group. A photosensitive resin composition, characterized in that the surface is treated with a silane coupling agent. According to paragraph 1,
The (C) silica is photosensitive, wherein, among the silane coupling agents coated on its surface, the amount covered by the silane coupling agent having the reactive functional group is greater than the amount coated by the silane coupling agent not having the reactive functional group. Resin composition. According to paragraph 2,
In the silica (C), 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 not having the reactive functional group is 2:1 to 10:1 on a mass basis. , photosensitive resin composition. According to paragraph 1,
A photosensitive resin composition in which the (C) silica is contained in a ratio of 50 to 90% by mass based on the total solid content in the photosensitive resin composition. According to paragraph 1,
(E) A photosensitive resin composition further comprising a thermosetting component. A dry film comprising a first film and a resin layer obtained by applying and drying the photosensitive resin composition according to claim 1 on one side of the first film. A cured product 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. A printed wiring board provided with a film made of the cured material according to claim 7.