JP2016177174A - Curable resin composition, dry film, cured product and printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable resin composition which makes it possible to obtain a cured product having excellent resolution and crack resistance with high sensitivity.SOLUTION: A curable resin composition comprises (A) an alkali-developable resin, (B) an epoxy resin, (C) a photoreaction initiator, (D) a photopolymerizable monomer and (E) a surface-treated inorganic filler, where a content of the (D) photopolymerizable monomer is 10 mass% or less in an organic solid content contained in the curable resin composition, and the (E) surface-treated inorganic filler has a reactive group which can react with at least one of the (A) alkali-developable resin, the (B) epoxy resin and the (D) photopolymerizable monomer.SELECTED DRAWING: None

Description

  The present invention relates to a curable resin composition, a dry film, a cured product, and a printed wiring board used for forming, for example, a solder resist of a printed wiring board.

In recent years, for example, solder resists have been required to have higher performance in response to the increase in the density of printed wiring boards accompanying the reduction in the size of electronic devices. Above all, the solder resist used for semiconductor package substrates is shifting to the flip chip method for connecting semiconductor chips and package substrates for high-density mounting, and the connection pitch is becoming narrower. In particular, it is required that a fine opening pattern can be formed with high sensitivity and high productivity.
Furthermore, insulation reliability is impaired due to the occurrence of cracks due to the difference in expansion coefficient between solder resist and solder resist peripheral members such as semiconductor chips and package substrates, etc. There is also a need to ensure that there is no such thing. For example, high crack resistance to TCT (temperature cycle test) and TST (thermal shock test) is required from the viewpoint of high reliability.
In addition, printed wiring boards mounted on automobile electronic devices are often mounted in places with high environmental temperatures, such as the engine room and its surroundings, while electric control of the drive unit of the automobile is progressing. Therefore, crack resistance is essential for the solder resist in the same manner as described above.

  About the improvement of crack resistance at the time of a thermal cycle, it contains a photosensitive resin having an epoxy group and a carboxyl group, an epoxy curing agent and a photopolymerization initiator, and the molar ratio of epoxy group / carboxyl group is 1.1 to 1.5. A photosensitive resin composition blended in such a manner has been proposed (see, for example, Patent Document 1).

JP 2003-280188 A

However, with such a technique, it has been difficult to obtain a cured product with high sensitivity and excellent balance between resolution and crack resistance.
In addition, in a curable resin composition containing a conventional alkali-developable resin, epoxy resin, photoinitiator, photopolymerizable monomer and inorganic filler, the amount of the photopolymerizable monomer is increased to achieve high sensitivity and high resolution. When trying to obtain image quality, curing shrinkage and cooling shrinkage after curing are large, so that a cured film is cracked or warped during high-temperature processing, which may have an adverse effect when mounting a semiconductor chip, for example.
In other words, by adjusting the epoxy resin / carboxyl molar ratio of the photosensitive resin or adjusting the blending amount of the photopolymerizable monomer, a cured product having an excellent balance of sensitivity, resolution and crack resistance can be obtained. I could not.
The object of the present invention is to advantageously solve the above-mentioned problems, a curable resin composition capable of obtaining a cured product having high sensitivity and excellent resolution and crack resistance, and applying the composition to a film. It is providing the dry film which has the resin layer obtained.
Another object of the present invention is to provide a cured product excellent in resolution and crack resistance using the curable resin composition, and a printed wiring board comprising the cured product.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have been difficult to obtain good sensitivity and crack resistance only by setting the content of the photopolymerizable monomer to 10% by mass or less. It has been found that by using together an inorganic filler that reacts with an alkali-developable resin or the like, a cured product having high sensitivity and high resolution and excellent crack resistance can be obtained.
Accordingly, the curable resin composition of one embodiment of the present invention includes (A) an alkali-developable resin, (B) an epoxy resin, (C) a photoreaction initiator, (D) a photopolymerizable monomer, and (E) a surface treatment. A curable resin composition containing an inorganic filler, wherein the content of the (D) photopolymerizable monomer is 10% by mass or less in an organic solid content contained in the curable resin composition; The (E) surface-treated inorganic filler has a reactive group capable of reacting with at least one of the (A) alkali developable resin, the (B) epoxy resin, and the (D) photopolymerizable monomer. It is characterized by that.

In another aspect of the curable resin composition of the present invention, in the curable resin composition, the (B) epoxy resin includes (b) a polyfunctional epoxy resin having a softening point of 60 ° C. or less and (b ′) softening. It is a mixture with a polyfunctional epoxy resin having a point exceeding 60 ° C., and (b) an epoxy group (b1) of a polyfunctional epoxy resin having a softening point of 60 ° C. or less and a polyfunctional epoxy having a softening point exceeding 60 ° C. The total with the epoxy group (b′1) of the resin is 1.2 equivalents or more and 2.5 equivalents or less with respect to 1 equivalent of the alkali developable group of the (A) alkali developable resin.
Another aspect of the curable resin composition of the present invention is characterized in that, in the curable resin composition, the (E) surface-treated inorganic filler is surface-treated silica.
In another aspect of the curable resin composition of the present invention, in the curable resin composition, the (b) epoxy group (b1) of the polyfunctional epoxy resin having a softening point of 60 ° C. or less and the (b ′) The ratio of the polyfunctional epoxy resin having a softening point exceeding 60 ° C. to the epoxy group (b′1) is 1: 0.1 to 1: 9.

Moreover, the dry film of another aspect of the present invention is characterized by having a resin layer obtained by applying and drying the curable resin composition on a film.
Moreover, the hardened | cured material of the other aspect of this invention is made by hardening the resin layer of the said curable resin composition or the said dry film, It is characterized by the above-mentioned.
Moreover, the printed wiring board of the other aspect of this invention comprises the said hardened | cured material, It is characterized by the above-mentioned.

  According to the present invention, a curable resin composition capable of obtaining a cured product with high sensitivity and excellent resolution and crack resistance of the cured product, and a dry resin having a resin layer obtained by applying the composition to a film. A cured product obtained by curing a resin layer of a film, the composition or the dry film, and a printed wiring board provided with the cured product can be provided.

Hereinafter, the present invention will be described in detail.
The curable resin composition of the present invention comprises (A) an alkali-developable resin, (B) an epoxy resin, (C) a photoreaction initiator, (D) a photopolymerizable monomer, and (E) a surface-treated inorganic filler. It is curable resin composition to contain, Comprising: Content of the said (D) photopolymerizable monomer is 10 mass% or less in the organic solid content contained in the said curable resin composition, Said (E) surface The treated inorganic filler has a reactive group capable of reacting with at least one of (A) alkali-developable resin, (B) epoxy resin, and (D) photopolymerizable monomer. Is. Here, when the curable resin composition contains an organic component, an inorganic filler, and an organic solvent, the organic solid content means only an organic component obtained by removing the inorganic filler and the organic solvent from the curable resin composition. .

First, each component contained in the curable resin composition of the present invention will be described.
<(A) Alkali developable resin>
The alkali developable resin has an alkali developable group that is soluble in an alkaline aqueous solution. The alkali-developable group is, for example, any one of a phenolic hydroxyl group, a thiol group, and a carboxyl group. Examples of the alkali-developing resin include compounds having two or more phenolic hydroxyl groups, carboxyl group-containing resins, compounds having phenolic hydroxyl groups and carboxyl groups, and compounds having two or more thiol groups.

  When the alkali-developable resin is a carboxyl group-containing resin or a phenol resin, the adhesion to the base is improved. In particular, when the alkali developable resin is a carboxyl group-containing resin, the developability is excellent. The carboxyl group-containing resin is preferably a carboxyl group-containing photosensitive resin having an ethylenically unsaturated double bond, but may be a carboxyl group-containing resin having no ethylenically unsaturated double bond.

Examples of the carboxyl group-containing resin include the following resins. However, it is not restricted to the following resins.
(1) Carboxyl group-containing photosensitivity in which (meth) acrylic acid is reacted with an epoxy resin, and a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride or hexahydrophthalic anhydride is added to the hydroxyl group present in the side chain Resin.
(2) Carboxy group-containing photosensitivity obtained by reacting (meth) acrylic acid with a polyfunctional epoxy resin obtained by epoxidizing the hydroxyl group of the epoxy resin with epichlorohydrin and adding a dibasic acid anhydride to the resulting hydroxyl group. Resin.
(3) Obtained by reacting an epoxy compound with a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule and an unsaturated group-containing monocarboxylic acid such as (meth) acrylic acid. Containing carboxyl groups obtained by reacting polyhydric acid anhydrides such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid with the alcoholic hydroxyl groups of the reaction products obtained Photosensitive resin.
(4) Two or more per molecule such as bisphenol A, bisphenol F, bisphenol S, novolac type phenol resin, poly-p-hydroxystyrene, condensate of naphthol and aldehydes, condensate of dihydroxynaphthalene and aldehydes Reaction obtained by reacting an unsaturated group-containing monocarboxylic acid such as (meth) acrylic acid with a reaction product obtained by reacting a compound having a phenolic hydroxyl group with an alkylene oxide such as ethylene oxide or propylene oxide A carboxyl group-containing photosensitive resin obtained by reacting a product with a polybasic acid anhydride.
(5) A reaction product obtained by reacting a compound having two or more phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate is reacted with an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting the resulting reaction product with a polybasic acid anhydride.
(6) Diisocyanate compounds such as aliphatic diisocyanate, branched aliphatic diisocyanate, alicyclic diisocyanate, aromatic diisocyanate, polycarbonate polyol, polyether polyol, polyester polyol, polyolefin polyol, acrylic polyol, bisphenol A type A terminal carboxyl group-containing urethane resin obtained by reacting an acid anhydride with a terminal of a urethane resin by a polyaddition reaction of a diol compound such as an alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.
(7) During synthesis of a carboxyl group-containing urethane resin by a polyaddition reaction between a diisocyanate, a carboxyl group-containing dialcohol compound such as dimethylolpropionic acid or dimethylolbutyric acid, and a diol compound, a molecule such as hydroxyalkyl (meth) acrylate A carboxyl group-containing urethane resin in which a compound having one hydroxyl group and one or more (meth) acryloyl groups is added and terminally (meth) acrylated.
(8) During synthesis of a carboxyl group-containing urethane resin by polyaddition reaction of a diisocyanate, a carboxyl group-containing dialcohol compound, and a diol compound, an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate, etc. A carboxyl group-containing urethane resin obtained by adding a compound having two isocyanate groups and one or more (meth) acryloyl groups, and then terminally (meth) acrylating.
(9) A 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.
(10) A carboxyl group-containing polyester resin obtained by reacting an oxetane resin with a dicarboxylic acid such as adipic acid, phthalic acid or hexahydrophthalic acid, and adding a dibasic acid anhydride to the resulting primary hydroxyl group, 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, such as glycidyl (meth) acrylate and α-methylglycidyl (meth) acrylate.
(11) A carboxyl group-containing photosensitive resin obtained by adding a compound having a cyclic ether group and a (meth) acryloyl group in one molecule to the carboxyl group-containing resins of (1) to (10) described above.

  Examples of the compound having a phenolic hydroxyl group include a compound having a biphenyl skeleton or a phenylene skeleton or both of them, phenol, orthocresol, paracresol, metacresol, 2,3-xylenol, 2,4-xylenol, 2 , 5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, catechol, resorcinol, hydroquinone, methylhydroquinone, 2,6-dimethylhydroquinone, trimethylhydroquinone, pyrogallol, phloroglucinol, etc. And phenol resins having various skeletons synthesized.

  Examples of the compound having a phenolic hydroxyl group include a phenol novolac resin, an alkylphenol volac resin, a bisphenol A novolac resin, a dicyclopentadiene type phenol resin, an Xylok type phenol resin, a terpene modified phenol resin, a polyvinylphenol, and bisphenol F. Bisphenol S-type phenol resin, poly-p-hydroxystyrene, condensates of naphthol and aldehydes, and condensates of dihydroxynaphthalene and aldehydes.

  Examples of commercially available phenol resins include HF1H60 (Maywa Kasei Co., Ltd.), Phenolite TD-2090, Phenolite TD-2131 (Dai Nippon Printing Co., Ltd.), Vesmol CZ-256-A (Dic Corporation), Siyonor BRG-555, Siyonor BRG-556 (manufactured by Showa Denko KK), CGR-951 (manufactured by Maruzen Petroleum Co., Ltd.), polyvinylphenol CST70, CST90, S-1P and S-2P (manufactured by Maruzen Petroleum Co., Ltd.) can be mentioned.

  (A) As alkali developable resin, the carboxyl group-containing resin of said (1)-(9) is preferable, and the carboxyl group-containing resin of said (4), (5) is more preferable from a viewpoint of HAST tolerance.

  (A) The acid value of the alkali-developable resin is suitably in the range of 40 to 200 mgKOH / g, more preferably in the range of 45 to 120 mgKOH / g. When the acid value of the alkali-developable resin is 40 mgKOH / g or more, alkali development is easy, and on the other hand, it is preferable to draw a normal resist pattern of 200 mgKOH / g or less.

  (A) Although the weight average molecular weight of alkali developable resin changes with resin frame | skeletons, the range of 1,500-150,000, Furthermore, 1,500-100,000 is preferable. When the weight average molecular weight is 1,500 or more, the tack-free performance is good, the moisture resistance of the coated film after exposure is good, the film loss during development can be suppressed, and the resolution can be suppressed from decreasing. On the other hand, when the weight average molecular weight is 150,000 or less, the developability is good and the storage stability is also excellent.

(A) The compounding quantity of alkali developable resin becomes like this. Preferably it is 5-50 mass% in all the compositions, More preferably, it is 10-50 mass%. In the case of 5 to 50% by mass, the coating film strength is good, the viscosity of the composition is moderate, and coatability and the like are improved.
(A) Alkali developable resin can be used individually by 1 type or in combination of 2 or more types.

<(B) Epoxy resin>
(B) The epoxy resin is a resin having an epoxy group in the molecule. The (B) epoxy resin is preferably a mixture of (b) a polyfunctional epoxy resin having a softening point of 60 ° C. or lower and (b ′) a polyfunctional epoxy resin having a softening point exceeding 60 ° C. (B) By including a polyfunctional epoxy resin having a softening point of 60 ° C. or lower, the reactivity is improved, and the shrinkage force in the thermal cycle test can be alleviated, so that the crack resistance is improved. On the other hand, (b ′) by including a polyfunctional epoxy resin having a softening point exceeding 60 ° C., the resolution can be improved and the glass transition temperature (Tg) of the entire curable resin composition can be increased. As a result, heat resistance such as PCT resistance and reliability such as crack resistance in the package substrate can be improved. Here, the softening point means a value measured according to the method described in JIS K 7234.

Moreover, the sum total of (b) the epoxy group (b1) of the polyfunctional epoxy resin having a softening point of 60 ° C. or lower and (b ′) the epoxy group (b′1) of the polyfunctional epoxy resin having a softening point exceeding 60 ° C. (A) It contains (b) epoxy resin and (b ') epoxy resin in the range which becomes 1.2 equivalent or more and 2.5 equivalent or less with respect to 1 equivalent of alkali developable groups of alkali developable resin. Is preferred.
For example, when (A) the alkali-developable resin is at least two selected from phenolic hydroxyl group-containing resins, carboxyl group-containing resins and thiol group-containing resins, the phenolic hydroxyl groups, carboxyl groups and thiols of these resins It is set as the range used as 1.2 equivalent or more and 2.5 equivalent or less with respect to the equivalent which combined group. This provides a good balance between sensitivity and resolution.
More preferably, the total of the epoxy group (B1) and the epoxy group (B′1) is 1.5 equivalents or more and 2.2 equivalents or less with respect to 1 equivalent of the alkali developable group of the (A) alkali developable resin. is there.

  (B) The polyfunctional epoxy resin having a softening point of 60 ° C. or lower may be a known resin, but is preferably liquid at room temperature of 20 to 30 ° C., for example. (B) As a polyfunctional epoxy resin having a softening point of 60 ° C. or less, for example, Epicoat 834, 828 (manufactured by Japan Epoxy Resin), YD-128 (manufactured by Toto Kasei), 840, 850 (manufactured by Japan Epoxy Resin) Bisphenol A type epoxy resin such as DIC (made by DIC), 806, 807 (made by Japan Epoxy Resin Co., Ltd.), YDF-170 (made by Tohto Kasei Co., Ltd.), 830, 835, N-730A (made by DIC), etc. Epoxy resin, mixture of bisphenol A and bisphenol F such as ZX-1059 (manufactured by Toto Kasei), hydrogenated bisphenol A type such as YX-8000, 8034 (manufactured by Japan Epoxy Resin) ST-3000 (manufactured by Toto Kasei) Epoxy resin, Nippon Kayaku's RE-306CA90, Dow Chemical's DEN4 1, novolac-type epoxy resins such as DEN438 like.

  (B) The molecular weight of the polyfunctional epoxy resin having a softening point of 60 ° C. or less is preferably 1000 or less, more preferably 800 or less, and even more preferably 600 or less, from the viewpoint of developability. preferable.

  (B) The content of the polyfunctional epoxy resin having a softening point of 60 ° C. or lower is preferably 0.2 to 1 for the epoxy group (b1) with respect to 1 equivalent of the alkali developable group of the (A) alkali developable resin. .8 equivalent range. (B) The softening point of the polyfunctional epoxy resin having a softening point of 60 ° C. or lower is preferably −80 ° C. or higher and 55 ° C. or lower, and more preferably −70 ° C. or higher and 50 ° C. or lower.

  (B ′) Examples of polyfunctional epoxy resins having a softening point exceeding 60 ° C. include ICTEP-S (softening point: 110 ° C.) manufactured by Nissan Chemical Co., Ltd., TEPIC-H, N870, JER1001 manufactured by Japan Epoxy Resin Co., Ltd. Bisphenol A type epoxy resin (softening point: 64 ° C.)).

  (B ′) The softening point of the polyfunctional epoxy resin having a softening point exceeding 60 ° C. is preferably 65 ° C. or higher, and more preferably 70 ° C. or higher. In addition, although the upper limit of the softening point in the (b ′) epoxy resin is not particularly limited, it is about 400 ° C. or less.

  The blending ratio of (b) a polyfunctional epoxy resin having a softening point of 60 ° C. or less and (b ′) an epoxy resin having a softening point of more than 60 ° C. is (b) an epoxy group of a polyfunctional epoxy resin having a softening point of 60 ° C. or less. (B1) and (b ′) The equivalent ratio (b1: b′1) to the epoxy group (b′1) of the polyfunctional epoxy resin having a softening point exceeding 60 ° C. is 1: 0.1 to 1: 9. It is preferable that the ratio is 1: 0.5 to 1: 5. By setting the ratio within the range, the balance of sensitivity, resolution, and crack resistance is improved.

  (B) A polyfunctional epoxy resin having a softening point of 60 ° C. or lower and (b ′) a polyfunctional epoxy resin having a softening point of 60 ° C. or higher can be used alone or in combination of two or more.

<(C) Photoreaction initiator>
(C) Photoinitiator should just be a thing which can harden a composition by light irradiation, (C1) The photoinitiator which generate | occur | produces a radical by light irradiation, and (C2) The photobase which generates a base by light irradiation Any one of the generators is preferred. The (C) photoreaction initiator may of course be a compound that generates both radicals and bases upon light irradiation. Light irradiation refers to irradiation with ultraviolet rays having a wavelength in the range of 350 to 450 nm.
(C1) As the photopolymerization initiator, for example, benzophenone-based, acetophenone-based, aminoacetophenone-based, benzoin ether-based, benzyl ketal-based, acylphosphine oxide-based, oxime ether-based, oxime ester-based, titanocene-based, etc. Compounds.

Among them, as the (C1) photopolymerization initiator, an oxime ester type containing a structural part represented by the general formula (I), an α-aminoacetophenone type containing a structural part represented by the general formula (II), a general formula ( It is preferable to contain one or more selected from the group consisting of acylphosphine oxides containing a structural moiety represented by III) and titanocenes represented by general formula (IV). In particular, the oxime ester photopolymerization initiator can obtain high reliability.

In general formula (I), R ¹ represents a hydrogen atom, a phenyl group, an alkyl group, a cycloalkyl group, an alkanoyl group or a benzoyl group. R ² represents a phenyl group, an alkyl group, a cycloalkyl group, an alkanoyl group or a benzoyl group.

The phenyl group represented by R ¹ and R ² may have a substituent, and examples of the substituent include an alkyl group having 1 to 6 carbon atoms, a phenyl group, and a halogen atom.

The alkyl group represented by R ¹ and R ² is preferably an alkyl group having 1 to 20 carbon atoms, and may contain one or more oxygen atoms in the alkyl chain. Further, it may be substituted with one or more hydroxyl groups.
The cycloalkyl group represented by R ¹ and R ² is preferably a cycloalkyl group having 5 to 8 carbon atoms.
The alkanoyl group represented by R ¹ and R ² is preferably an alkanoyl group having 2 to 20 carbon atoms.
The benzoyl group represented by R ¹ and R ² may have a substituent, and examples of the substituent include an alkyl group having 1 to 6 carbon atoms and a phenyl group.

In the general formula (II), R ³ and R ⁴ each independently represent an alkyl group having 1 to 12 carbon atoms or an arylalkyl group, and R ⁵ and R ⁶ each independently represent a hydrogen atom or a carbon number 1 to 6 alkyl groups may be represented, or two may be bonded to form a cyclic alkyl ether group.

In general formula (III), R ⁷ and R ⁸ are each independently an alkyl group having 1 to 10 carbon atoms, a cyclohexyl group, a cyclopentyl group, an aryl group, or an aryl substituted with a halogen atom, an alkyl group or an alkoxy group. Group or a carbonyl group having 1 to 20 carbon atoms (except when both are carbonyl groups having 1 to 20 carbon atoms).

In general formula (IV), R ⁹ and R ¹⁰ each independently represent a halogen atom, an aryl group, a halogenated aryl group, or a heterocycle-containing halogenated aryl group.

Examples of the oxime ester-based photopolymerization initiator containing the structural portion represented by the general formula (I) include 1,2-octanedione-1- [4- (phenylthio) -2- (O-benzoyloxime)], ethanone , 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime), a compound represented by the following formula (I-1), 2 Examples include-(acetyloxyiminomethyl) thioxanthen-9-one and compounds represented by the following general formula (I-2).

In formula (I-2), R ¹¹ has the same meaning as R ¹ in general formula (I), and R ¹² and R ¹⁴ each independently have the same meaning as R ² in general formula (I). R ¹³ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclohexyl group, a phenyl group, a benzyl group, a benzoyl group, an alkanoyl group having 2 to 12 carbon atoms, or an alkoxy having 2 to 12 carbon atoms. A carbonyl group (when the alkyl group constituting the alkoxyl group has 2 or more carbon atoms, the alkyl group may be substituted with one or more hydroxyl groups, and has one or more oxygen atoms in the middle of the alkyl chain) Or a phenoxycarboxylic group.

  Of the oxime ester photopolymerization initiators, compounds represented by the above formula (I-2) are preferred. The oxime ester photopolymerization initiator may be a compound having a plurality of oxime ester groups.

  As the α-aminoacetophenone photopolymerization initiator containing a structural moiety represented by the general formula (II), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 2- Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) ) Phenyl] -1-butanone, N, N-dimethylaminoacetophenone and the like.

Examples of the acylphosphine oxide-based photopolymerization initiator containing a structural portion represented by the general formula (III) include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine. Fin oxide, bis (2,6
-Dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide.

Examples of the titanocene photopolymerization initiator represented by the general formula (IV) include bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) 1-yl) -phenyl) titanium and the like.

  When the wavelength of exposure light is h-line (405 nm) or i-line (365 nm), the absorbance at 405 nm or 365 nm is 0.4 to 1.5 at a film thickness of 10 to 20 μm in the dry coating film of the curable resin composition. Thus, it is preferable from the viewpoint of resolution to adjust the content of (C) the photoreaction initiator.

(C2) The photobase generator functions as a catalyst for the polymerization reaction of the above (B) epoxy resin when the molecular structure is changed by light irradiation such as ultraviolet light or visible light, or when the molecule is cleaved. And a compound that produces one or more basic substances that can function as a catalyst for the addition reaction between the alkali-developable resin and the (B) epoxy resin. Examples of basic substances include secondary amines and tertiary amines.
Examples of the photobase generator include the α-aminoacetophenone compound, the oxime ester compound, an acyloxyimino group, an N-formylated aromatic amino group, an N-acylated aromatic amino group, a nitrobenzyl carbamate group, an alcohol, and the like. Examples thereof include compounds having a substituent such as an oxybenzyl carbamate group. Of these, oxime ester compounds are preferred.

  Examples of the compound having an acyloxyimino group include O, O′-diacetphenone oxime succinate, O, O′-dinaphthophenone oxime succinate, and a benzophenone oxime acrylate-styrene copolymer.

  Examples of the compound having an N-formylated aromatic amino group and an N-acylated aromatic amino group include di-N- (p-formylamino) diphenylmethane, di-N (p-aceethylamino) diphenylmelane, Di-N- (p-benzoamido) diphenylmethane, 4-formylaminotoluylene, 4-acetylaminotoluylene, 2,4-diformylaminotoluylene, 1-formylaminonaphthalene, 1-acetylaminonaphthalene, 1,5 -Diformylaminonaphthalene, 1-formylaminoanthracene, 1,4-diformylaminoanthracene, 1-acetylaminoanthracene, 1,4-diformylaminoanthraquinone, 1,5-diformylaminoanthraquinone, 3,3'- Dimethyl-4,4′-diformylaminobiphenyl, 4, '- di formylamino benzophenones.

  Examples of the compound having a nitrobenzyl carbamate group and an alkoxybenzyl carbamate group include bis {{(2-nitrobenzyl) oxy} carbonyl} diaminodiphenylmethane, 2,4-di {{(2-nitrobenzyl) oxy} toluylene. Bis {{(2-nitrobenzyloxy) carbonyl} hexane-1,6-diamine, m-xylidine {{(2-nitro-4-chlorobenzyl) oxy} amide}.

  The photobase generator is preferably at least one of an oxime ester compound and an α-aminoacetophenone compound, and more preferably an oxime ester compound. As the α-aminoacetophenone compound, those having two or more nitrogen atoms are particularly preferable.

As other photobase generators,
WPBG-018 (Product name: 9-anthrylmethyl N, N'-diethylcarbamate), WPBG-027 (Product name: (E) -1- [3- (2-hydroxyphenyl) -2-propenoyl] piperidine), WPBG-082 A photobase generator such as (trade name: guanidinium 2- (3-benzoylphenyl) propionate), WPBG-140 (trade name: 1- (anthraquinon-2-yl) ethyl imidazolecarboxylate) can also be used.

  (C) It is preferable that content of a photoinitiator is 0.1 to 30 mass parts with respect to 100 mass parts of alkali developable resin.

<(D) Photopolymerizable monomer>
(D) The photopolymerizable monomer is a compound having an ethylenically unsaturated double bond. (D) Examples of the photopolymerizable monomer include alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) Hydroxyalkyl (meth) acrylates such as acrylates; Mono- or di (meth) acrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol; hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane Polyhydric alcohols such as dipentaerythritol and trishydroxyethyl isocyanurate, or ethylene oxide or propylene oxide adducts thereof. (Meth) acrylates; (meth) acrylates of ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth) acrylate and polyethoxydi (meth) acrylate of bisphenol A; glycerin diglycidyl ether, trimethylolpropane triglycidyl (Meth) acrylates of glycidyl ethers such as ether and triglycidyl isocyanurate; and melamine (meth) acrylates.

  (D) Content of a photopolymerizable monomer is 10 mass% or less in solid content of an organic composition. By containing the photopolymerizable monomer at a ratio of 10% by mass or less, excellent crack resistance and resolution with high sensitivity can be secured. (D) It is preferable that content of a photopolymerizable monomer is 1 mass% or more and 8 mass% or less in solid content of an organic composition from the balance of a sensitivity, crack tolerance, and resolution.

<(E) Surface-treated inorganic filler>
(E) The surface-treated inorganic filler has a reactive group capable of reacting with at least one of (A) an alkali-developable resin, (B) an epoxy resin, and (D) a photopolymerizable monomer. .
Examples of the reactive group of the (E) surface-treated inorganic filler include a (meth) acryloyl group, a vinyl group, a cyclic (thio) ether group, an acidic group, and a basic group.
Examples of the cyclic (thio) ether group include an epoxy group, an oxetanyl group, and an episulfide group.
Examples of the acidic group include a carboxyl group, a phenolic hydroxyl group, an alcoholic hydroxyl group, a thiol group, a sulfone group, and a phosphate group.
Examples of the basic group include an amino group, an amide group, and an ammonium group.
(E) It is preferable that the reactive group of the surface-treated inorganic filler is any one of a (meth) acryloyl group, a vinyl group, and a cyclic (thio) ether group. (E) When the reactive group of the surface-treated inorganic filler is a cyclic (thio) ether group, the crack resistance is excellent, and when it is a (meth) acryloyl group or a vinyl group, sensitivity and resolution are excellent.

(E) It is preferable that the average particle diameter of the surface-treated inorganic filler is 0.5 μm or less. When the thickness is 0.5 μm or less, a decrease in resolution can be suppressed.
(E) The content of the surface-treated inorganic filler is, for example, 10 to 80% by mass based on the total solid content of the curable resin composition. (E) When the content of the surface-treated inorganic filler is 10 to 80% by mass, the coatability is good, and a cured product having excellent characteristics as a solder resist for IC packages is obtained. In particular, when the content of the (E) surface-treated inorganic filler is 30 to 80% by mass based on the total solid content of the curable resin composition, sensitivity and crack resistance are improved.

(E) The surface-treated inorganic filler is preferably silica that has been surface-treated, and more preferably silica that has been surface-treated with a coupling agent.
Examples of the coupling agent include silane-based, titanate-based, aluminate-based, and zircoaluminate-based coupling agents. Of these, silane coupling agents are preferred. Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminomethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) -3-amino. Propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxy (Cyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like. These can be used alone or in combination. These silane coupling agents are preferably immobilized in advance on the surface of the inorganic filler by adsorption or reaction.
In the present invention, (E) the surface-treated inorganic filler may be an inorganic filler other than silica. For example, barium sulfate, barium titanate, Neuburg silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide , Titanium oxide, aluminum hydroxide, silicon nitride, and aluminum nitride may be used.
(D) A filler can be used individually by 1 type or in combination of 2 or more types.

<Colorant>
The curable resin composition of the present invention may contain a colorant. As the colorant, conventionally known colorants such as red, blue, green, yellow, white, and black can be used, and any of pigments, dyes, and pigments may be used.

  Specific examples include those with the following color index numbers (CI: issued by The Society of Dyer's and Colorists).

Examples of the red colorant include monoazo series, diazo series, azo lake series, benzimidazolone series, perylene series, diketopyrrolopyrrole series, condensed azo series, anthraquinone series, and quinacridone series. Examples of the blue colorant include phthalocyanine-based and anthraquinone-based compounds, and pigment-based compounds that can be used are pigments. In addition to these, metal-substituted or unsubstituted phthalocyanine compounds can also be used. Similarly, the green colorant includes phthalocyanine, anthraquinone and perylene. In addition to these, metal-substituted or unsubstituted phthalocyanine compounds can also be used. Examples of the yellow colorant include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone. Examples of the white colorant include rutile type or anatase type titanium oxide. Black colorants include carbon black, graphite, iron oxide, titanium black, iron oxide, anthraquinone, cobalt oxide, copper oxide, manganese, antimony oxide, nickel oxide, perylene, and aniline. System, molybdenum sulfide, bismuth sulfide and the like.
In addition, a colorant such as purple, orange or brown may be added for the purpose of adjusting the color tone.

  The content of the colorant is, for example, preferably 0.01 to 70% by mass, more preferably 0.05 to 60% by mass, based on the total amount of the composition. When the content of the colorant is 70% by mass or less, the printability of the composition is good. On the other hand, when the content is 0.01% by mass or more, patterning can be performed satisfactorily. In this invention, a coloring agent may be used individually by 1 type, and may be used in combination of 2 or more type.

<Thermosetting catalyst>
The curable resin composition of the present invention may contain a thermosetting catalyst. Examples of the thermosetting catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- ( Imidazole derivatives such as 2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine Amine compounds such as 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic hydrazide and sebacic acid hydrazide; and phosphorus compounds such as triphenylphosphine. Commercially available thermosetting catalysts include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd., U-CAT3503N, U -CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof), and the like. In addition, it is not restricted to these, What is necessary is just to be the thing which accelerates | stimulates the reaction of the epoxy resin thermosetting catalyst or an epoxy group, and a carboxyl group, and it may be used individually or in mixture of 2 or more types. . Guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2 S-triazine derivatives such as -vinyl-4,6-diamino-S-triazine / isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct can also be used, Preferably, a compound that also functions as an adhesion promoter is used in combination with the thermosetting catalyst.

  The content of the thermosetting catalyst may be a ratio usually used, for example, (A) 0.1 to 20 parts by mass, preferably 0.5 to 15.0 parts by mass with respect to 100 parts by mass of the alkali-developable resin. The ratio can be used.

<Organic solvent>
The curable resin composition of the present invention may contain an organic solvent. The organic solvent is used for adjusting the viscosity of the curable resin composition of the present invention to improve workability, and a known and commonly used organic solvent can be used. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methylcellosolve, butylcellosolve, carbitol, methylcarbitol, butylcarbitol, propylene glycol monomethyl Glycol ethers such as ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether; 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, Esters such as acid propylene; octane, aliphatic hydrocarbons decane; petroleum ether, petroleum naphtha, and petroleum solvents such as solvent naphtha, or an organic solvent conventionally known. These organic solvents can be used alone or in combination of two or more.

  The content of the organic solvent varies depending on the coating method and the boiling point of the organic solvent to be used, and is not particularly limited. However, in general, the total composition is preferably 80% by mass or less, more preferably 60% by mass. % Or less, and more preferably 50% by mass or less. When a high-boiling organic solvent is contained in a large amount, the dryness to the touch is lowered, and sagging or the like occurs after the coating until it is temporarily dried.

<Other ingredients>
The curable resin composition of the present invention may contain an elastomer and a block copolymer in order to improve crack resistance. Further, if necessary, known and conventional thermal polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol and phenothiazine, known and conventional thickeners such as fine silica, organic bentonite and montmorillonite, silicone type Fluorine-based and polymer-based antifoaming agents and leveling agents, imidazole-based, thiazole-based, triazole-based silane coupling agents, and the like can be added.

<Dry film>
The curable resin composition of this invention can also be made into the form of the dry film which has the resin layer formed with the said curable resin composition on the film generally called a support film or a carrier film. When forming a dry film, the curable resin composition of the present invention is diluted with the above-mentioned organic solvent to adjust to an appropriate viscosity, and a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater A resin layer is obtained by applying a uniform thickness on a carrier film with a gravure coater, spray coater or the like, and drying usually at a temperature of 50 to 130 ° C. for 1 to 30 minutes. Although there is no restriction | limiting in particular about the thickness to which a curable resin composition is apply | coated, Generally, the resin layer after drying is suitably selected so that it may become the range of 1-150 micrometers, Preferably it is 10-60 micrometers in thickness.

  A plastic film is used as the film, and a plastic film such as a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, or a polystyrene film is preferably used. Although there is no restriction | limiting in particular about the thickness of a carrier film, Generally, it selects suitably in the range of 10-150 micrometers.

  After the resin layer of the curable resin composition of the present invention is formed on the carrier film, a peelable cover 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 preferable. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper or the like can be used. From the adhesive force between the resin layer and the carrier film when peeling the cover film As long as the adhesive force between the resin layer and the cover film is smaller.

<Printed wiring board>
A printed wiring board has the hardened | cured material which consists of a curable resin composition on the base material which has a circuit pattern. The printed wiring board of the present invention can be produced by the following method.

  First, the curable resin composition of the present invention is adjusted to a viscosity suitable for the coating method with an organic solvent, for example, on a circuit-formed substrate, a dip coating method, a flow coating method, a spin coating method, a roll coating method, Coating by bar coater method, screen printing method, curtain coating method, etc., and forming a dry coating film by volatile drying (temporary drying) the organic solvent contained in the composition at a temperature of about 60-100 ° C. To do. Then, it selectively exposes with an ultraviolet-ray through a photomask, The unexposed part is developed with dilute alkaline aqueous solution (for example, 0.3-3% sodium carbonate aqueous solution), and the hardened | cured material which has a pattern is formed. Here, when the curable resin composition of this invention contains a photobase generator, it is preferable to heat a dry coating film after image development before exposure. The heating temperature is, for example, 70 to 140 ° C.

  For high-frequency circuits using paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, fluorine / polyethylene / PPO / cyanate ester, etc. A material using a material such as a copper-clad laminate and a copper-clad laminate of all grades (such as FR-4), other polyimide films, PET films, glass substrates, ceramic substrates, wafer plates and the like can be mentioned.

  Volatile drying performed after the curable resin composition is applied may be performed by using a hot air circulation drying furnace, an IR furnace, a hot plate, a convection oven, etc. And a method of spraying on a support from a nozzle). The exposure apparatus used for the ultraviolet irradiation may be an exposure apparatus that generates ultraviolet rays. For example, the apparatus which irradiates a laser beam, a lamp light, and LED light is mentioned.

  As the light source, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp or the like is preferable. Examples of the exposure apparatus include HMW-680GW manufactured by Oak Manufacturing Co., Ltd. and ADEX 600P manufactured by Adtech Engineering Co., Ltd., which can be used in the present invention. In addition, as an exposure apparatus for direct imaging that performs exposure at a single wavelength, a direct drawing apparatus (for example, a laser direct imaging apparatus that directly draws an image with a laser using CAD data from a computer), an ultraviolet lamp such as a (super) high pressure mercury lamp, and the like. The direct drawing apparatus used can be used. As such a direct drawing apparatus, for example, those made by Nippon Orbotech, Oak, etc. can be used.

  Development methods include dipping, showering, spraying, brushing, etc. Developers include potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, tetra An alkaline aqueous solution such as methylammonium hydroxide can be used.

  Moreover, a printed wiring board can also be manufactured using the dry film of this invention. For example, after the dry film of the present invention is bonded onto a base material on which a circuit pattern is formed, a printed wiring board can be produced through the same exposure and development steps as described above.

  The curable resin composition of the present invention is suitable as a material for forming a cured film of a printed wiring board, but is particularly suitable as a material for forming a permanent film of a printed wiring board, and particularly for forming a permanent insulating film such as a solder resist. Suitable as a material. The curable resin composition of the present invention can also be used as a coverlay forming material and an interlayer insulating layer forming material.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, it cannot be overemphasized that this invention is not what is limited to the following. In the following, “parts” and “%” indicate “parts by mass” and “% by mass” unless otherwise specified.

(Synthesis Example 1)
A flask equipped with a condenser and a stirrer was charged with 456 parts of bisphenol A, 228 parts of water, and 649 parts of 37% formalin, kept at a temperature of 40 ° C. or less, and 228 parts of 25% aqueous sodium hydroxide solution was added. The reaction was carried out at 50 ° C. for 10 hours. After completion of the reaction, the reaction mixture was cooled to 40 ° C. and neutralized to pH 4 with a 37.5% phosphoric acid aqueous solution while maintaining the temperature at 40 ° C. or lower. Thereafter, the mixture was allowed to stand to separate the aqueous layer. After separation, 300 parts of methyl isobutyl ketone was added and dissolved uniformly, and then washed three times with 500 parts of distilled water, and water, solvent, and the like were removed under reduced pressure at a temperature of 50 ° C. or lower. The obtained polymethylol compound was dissolved in 550 parts of methanol to obtain 1230 parts of a methanol solution of the polymethylol compound.
When a part of the methanol solution of the obtained polymethylol compound was dried at room temperature in a vacuum dryer, the solid content was 55.2%.

A flask equipped with a condenser and a stirrer was charged with 500 parts of a methanol solution of the obtained polymethylol compound and 440 parts of 2,6-xylenol, and uniformly dissolved at 50 ° C. After dissolving uniformly, methanol was removed under reduced pressure at a temperature of 50 ° C. or lower. Thereafter, 8 parts of oxalic acid was added and reacted at 100 ° C. for 10 hours. After completion of the reaction, the distillate was removed under reduced pressure at 180 ° C. and 50 mmHg to obtain 550 parts of novolak resin A.
In an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device, and a stirring device, 130 parts of novolak resin A, 2.6 parts of 50% aqueous sodium hydroxide, toluene / methyl isobutyl ketone (mass ratio = 2/1) 100 parts were charged, and the system was purged with nitrogen while stirring. Next, the temperature was raised by heating, and 60 parts of propylene oxide was gradually introduced and reacted at 150 ° C. and 8 kg / cm ² . The reaction was continued for about 4 hours until the gauge pressure reached 0.0 kg / cm ^2, and then cooled to room temperature. To this reaction solution, 3.3 parts of 36% aqueous hydrochloric acid was added and mixed to neutralize sodium hydroxide. The neutralized reaction product was diluted with toluene, washed with water three times, and the solvent was removed with an evaporator. The hydroxyl value was 189 g / eq. A propylene oxide adduct of novolak resin A was obtained. This was an average of 1 mole of propylene oxide added per equivalent of phenolic hydroxyl group.

Propylene oxide adduct 189 parts of the obtained novolak resin A, 36 parts of acrylic acid, 3.0 parts of p-toluenesulfonic acid, 0.1 part of hydroquinone monomethyl ether and 140 parts of toluene were stirred, a thermometer, an air blowing tube Was stirred while blowing air, heated to 115 ° C., reacted for an additional 4 hours while distilling off the water produced by the reaction as an azeotrope with toluene, and then brought to room temperature. Cooled down. The obtained reaction solution was washed with 5% NaCl aqueous solution and toluene was removed by distillation under reduced pressure. Diethylene glycol monoethyl ether acetate was added to obtain an acrylate resin solution having a nonvolatile content of 67%.
Next, in a four-necked flask equipped with a stirrer and a reflux condenser, 322 parts of the obtained acrylate resin solution, 0.1 part of hydroquinone monomethyl ether, and 0.3 part of triphenylphosphine were charged. Then, 60 parts of tetrahydrophthalic anhydride was added, reacted for 4 hours, cooled and taken out. The carboxyl group-containing photosensitive resin thus obtained had a nonvolatile content of 70% and a solid content acid value of 86 mgKOH / g. Hereinafter, this carboxyl group-containing photosensitive resin is referred to as A-1.

(Synthesis Example 2)
700 g of diethylene glycol monoethyl ether acetate and 1070 g of orthocresol novolak type epoxy resin (manufactured by DIC, EPICLON N-695, softening point 95 ° C., epoxy equivalent 214, average functional group number 7.6) (number of glycidyl groups (total number of aromatic rings)) ): 5.0 mol), 360 g (5.0 mol) of acrylic acid, and 1.5 g of hydroquinone were charged, heated and stirred at 100 ° C., and uniformly dissolved.
Next, 4.3 g of triphenylphosphine was charged, heated to 110 ° C. and reacted for 2 hours, and further 1.6 g of triphenylphosphine was added, and the temperature was raised to 120 ° C. and reacted for another 12 hours. To the obtained reaction liquid, 562 g of aromatic hydrocarbon (Sorvesso 150) and 684 g (4.5 mol) of tetrahydrophthalic anhydride were charged and reacted at 110 ° C. for 4 hours. Furthermore, 142.0 g (1.0 mol) of glycidyl methacrylate was added to the obtained reaction solution and reacted at 115 ° C. for 4 hours to obtain a photosensitive carboxyl group-containing resin solution. The resin solution thus obtained had a solid content of 65% and an acid value of the solid content of 87 mgKOH / g. Hereinafter, this carboxyl group-containing photosensitive resin is referred to as A-2.

[Preparation of curable resin composition]
Each component shown in Tables 1 to 3 was appropriately dispersed by adding an organic solvent, and kneaded with a three-roll mill to obtain a curable resin composition. In Tables 1 to 3, the content of each component of (A), (B) and the colorant is a solid content excluding the solvent.

<(A) Alkali developable resin>
(A) (A-1) to (A-3) were used as alkali developable resins.
A-1: Carboxyl group-containing resin of Synthesis Example 1 A-2: Carboxyl group-containing resin of Synthesis Example 2 A-3: P7-532 (carboxyl group-containing photosensitive urethane resin, manufactured by Kyoeisha Chemical Co., Ltd., solid content 54%, Acid value: 25mgKOH / g)

<(B) Epoxy resin>
828: bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, softening point 30 ° C. or less)
RE306: Polyglycidyl ether of phenol novolac (Nippon Kayaku Co., Ltd., epoxy equivalent 196, softening point 50 ° C., molecular weight 400)
N-730A: Novolac epoxy resin (manufactured by DIC, softening point of 30 ° C. or less)
N-870: Bisphenol A novolac type epoxy resin (manufactured by DIC, epoxy equivalent 205, softening point 70 ° C.)
YX4000: Boxylenol type epoxy resin (manufactured by Mitsubishi Chemical Corporation, softening point exceeding 60 ° C)

<(C) Photoreaction initiator>
OXE02: Oxime ester photopolymerization initiator (BASF Japan)
TPO: acylphosphine oxide photopolymerization initiator (BASF Japan)
ITX: 2-isopropyl-9H-thioxanthen-9-one

<(D) Photopolymerizable monomer>
DPHA: dipentaerythritol hexaacrylate, hexafunctional photoreactive monomer (Nippon Kayaku Co., Ltd.)
LR8863: Trifunctional acrylate monomer, manufactured by BASF Japan

<(E) Surface-treated inorganic filler>
Silica with a primary particle size (average particle size) of 0.5 μm treated with silane coupling <Other: Filler>
Surface untreated silica: E-22 (manufactured by CIK Nanotech)
<Thermosetting catalyst>
Melamine DICY: Dicyandiamide <Colorant>
Blue: Pigment Blue Yellow: Pigment Yellow

[Evaluation methods of Examples 1-21 and Comparative Examples 1-3]
The evaluation results of Examples 1-21 and Comparative Examples 1-3 are shown in Tables 4-6. In addition, the evaluation method of each evaluation is as follows.

[Examples 1 to 21 and Comparative Examples 1 to 3]
(Production of dry film)
Using the curable resin compositions of Examples 1 to 21 and Comparative Examples 1 to 3, dry films each having a resin layer were prepared. The dry film was prepared by applying a curable resin composition onto a film using an applicator using a polyester film having a thickness of 38 μm as a film and drying at 80 ° C. for 10 minutes.

<Optimal exposure>
A single-sided printed wiring board (also referred to as a substrate) having a copper thickness of 15 μm was prepared and pretreated using CZ8100 manufactured by MEC. The dry film according to each of the examples and comparative examples was bonded to this substrate using a vacuum laminator so that the resin layer was in contact with the substrate, thereby forming a resin layer on the substrate. This substrate is exposed through a step tablet (Stuffer 41 stage) using a projection exposure apparatus and developed (30 ° C., 0.2 MPa, 1% by mass Na ₂ CO ₃ aqueous solution) in 60 seconds. The optimal exposure amount was determined when the tablet pattern was 8 steps. The thickness of this resin layer was 15 μm. However, in Examples 17 to 21, the same development was performed after drying at 80 ° C. for 20 minutes after exposure.
The high sensitivity is desirably 500 mJ / cm ² or less. More preferably, it is 300 mJ / cm ² or less.

<Resolution>
A substrate having a resin layer was prepared in the same manner as in the case of measuring the optimum exposure amount, and the resin layer was exposed to the optimum exposure amount, followed by development (1% by mass Na ₂ CO ₃ aqueous solution, 30 ° C., 0.2 MPa). After 60 seconds, the 50 μm opening of the cured film was measured. The design value of the opening diameter was 50 μm.
A: The aperture ratio is 80% or more with respect to the design value, and the ratio of the aperture diameter between the top and bottom of the aperture is within 0.9 to 1.1.
A: The aperture ratio is 80% or more with respect to the design value, and the ratio of the aperture diameter between the top and bottom of the aperture exceeds the range of 0.9 to 1.1.
Δ: The opening ratio is 50% or more and less than 80%, and the ratio of the opening diameter between the top and bottom of the opening exceeds the range of 0.9 to 1.1.
X: An opening pattern was not obtained.

<Crack resistance>
Evaluation that a 3 mm square resist pattern was formed on a copper line after applying a curable resin composition to a substrate on which a 2 mm copper line pattern was formed, exposing and developing in the same manner as described above, and thermosetting. A substrate was produced. This evaluation board | substrate was put into the thermal cycle machine with which a temperature cycle is performed between -65 degreeC and 150 degreeC, and TCT (Thermal Cycle Test) was performed. The appearance at 600 cycles, 800 cycles and 1000 cycles was observed.
A: No abnormality at 1000 cycles.
○: Cracks occurred after 1000 cycles.
Δ: Cracks occurred in 800 cycles.
X: Cracks occurred at 600 cycles.

Since the curable resin composition of Comparative Example 1 did not contain (D) a photopolymerizable monomer, sensitivity and resolution were insufficient. The curable resin composition of Comparative Example 2 had insufficient crack resistance because the content of the photopolymerizable monomer (D) exceeded 10%. Since the curable resin composition of Comparative Example 3 contained silica that was not surface-treated, the sensitivity and crack resistance were insufficient.
On the other hand, in the curable resin compositions of Examples 1 to 21, it was possible to obtain a cured product with high sensitivity and excellent resolution and crack resistance of the cured product.

Claims (7)

A curable resin composition comprising (A) an alkali-developable resin, (B) an epoxy resin, (C) a photoreaction initiator, (D) a photopolymerizable monomer, and (E) a surface-treated inorganic filler. ,
Content of the said (D) photopolymerizable monomer is 10 mass% or less in the organic solid content contained in the said curable resin composition,
The (E) surface-treated inorganic filler has a reactive group capable of reacting with at least one of the (A) alkali developable resin, the (B) epoxy resin, and the (D) photopolymerizable monomer. A curable resin composition characterized by that. The (B) epoxy resin is a mixture of (b) a polyfunctional epoxy resin having a softening point of 60 ° C. or lower and (b ′) a polyfunctional epoxy resin having a softening point exceeding 60 ° C.
The sum of (b) the epoxy group (b1) of the polyfunctional epoxy resin having a softening point of 60 ° C. or lower and the epoxy group (b′1) of the polyfunctional epoxy resin having a softening point exceeding 60 ° C. A) The curable resin composition according to claim 1, which is 1.2 equivalents or more and 2.5 equivalents or less with respect to 1 equivalent of the alkali developable group of the alkali developable resin.   The curable resin composition according to claim 1 or 2, wherein the (E) surface-treated inorganic filler is surface-treated silica.   The ratio of the (b) epoxy group (b1) of the polyfunctional epoxy resin having a softening point of 60 ° C. or lower and the epoxy group (b′1) of the polyfunctional epoxy resin having a softening point of more than 60 ° C. is 1: The curable resin composition according to claim 2 or 3, which is 0.1 to 1: 9.   It has a resin layer obtained by apply | coating and drying the curable resin composition of any one of Claims 1-4 on a film, The dry film characterized by the above-mentioned.   Hardened | cured material formed by hardening the resin layer of the curable resin composition of any one of Claims 1-4, or the dry film of Claim 5.   A printed wiring board comprising the cured product according to claim 6.