JP2014199415A - Photocurable resin composition, dry film and cured product thereof, and printed wiring board having cured coating film formed by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocurable resin composition which excels in adhesiveness to a substrate and flexibility, which has a low generation rate of cracks or warpage in a cured product and excellent resolution, and which is developable with an alkali aqueous solution, and to provide a photocurable dry film and a cured product of the composition, and a printed wiring board including these components.SOLUTION: The photocurable resin composition comprises (A) an alkali-soluble resin, (B) a photopolymerization initiator, and (C) a spherical silica filler having an average particle diameter of 300 nm or less, in which the (C) spherical silica filler having an average particle diameter of 300 nm or less is compounded by 60 mass% or more with respect to the total amount of the photocurable resin composition; and the composition is developable with an alkali aqueous solution. A photocurable dry film and a cured product of the composition, and a printed wiring board including these components are also obtained.

Description

  The present invention relates to a photocurable resin composition that can be developed with an aqueous alkali solution, in particular, a photocurable resin composition for a solder resist that is photocured by ultraviolet exposure or laser exposure, a dry film and a cured product thereof, and using them. The present invention relates to a printed wiring board having a formed cured film.

  Currently, solder resists for some consumer printed wiring boards and most industrial printed wiring boards are imaged by developing after UV irradiation from the viewpoint of high accuracy and high density, A liquid development type solder resist that is finish-cured (mainly cured) at least one of them is used.

  Among these, in consideration of environmental problems, an alkali development type photo solder resist using an alkaline aqueous solution as a developing solution has become the mainstream, and is used in large quantities in the actual production of printed wiring boards.

  In such a conventional alkali development type photo solder resist, a carboxyl group-containing resin, particularly an epoxy acrylate-modified resin is generally used.

  For example, Patent Document 1 discloses a solder resist composition comprising a photosensitive resin obtained by adding an acid anhydride to a reaction product of a novolak-type epoxy compound and an unsaturated monobasic acid, a photopolymerization initiator, a diluent, and an epoxy compound. It has been reported.

  Patent Document 2 discloses that (meth) acrylic acid is added to an epoxy resin obtained by reacting a reaction product of salicylaldehyde with a monohydric phenol with epichlorohydrin, and a polybasic carboxylic acid or A solder resist composition comprising a photosensitive resin obtained by reacting the anhydride, a photopolymerization initiator, an organic solvent and the like is disclosed.

  Further, Patent Document 3 discloses a polyurethane compound obtained by reacting an epoxy acrylate compound having an ethylenically unsaturated group and two or more hydroxyl groups, a diisocyanate compound, and a diol compound having a carboxyl group, an ethylenically unsaturated group. A photosensitive resin composition containing a photopolymerizable monomer having a saturated group, a photopolymerization initiator, an epoxy compound, and a silica filler having an average particle diameter of 3 to 300 nm is disclosed.

JP 61-243869 (Claims) Japanese Patent Laid-Open No. 3-250012 (Claims) JP 2011-013622 A (Claims)

  However, conventional alkali-developable photo solder resist inks have a coating film durability, especially chemical resistance (for example, alkali resistance), water resistance, heat resistance and There is still room for improvement in terms of adhesion to the substrate.

  This is considered to be due to the influence of the main component hydrophilic group-containing component used to enable alkali development. That is, the hydrophilic group-containing component allows easy penetration of chemicals, water, water vapor, and the like. Thereby, there exists a tendency for the chemical resistance of a resist and the adhesiveness of a resist membrane | film | coat and copper to fall.

  In addition, conventional alkali-development type photo solder resist inks have a large shrinkage due to curing and cooling shrinkage after curing. May have an effect. In particular, when a filler is filled in the solder resist ink, the coating film may be cracked regardless of the type or particle size. In particular, when the filling was high, the occurrence of cracks in the coating film was significant.

  In the future, printed wiring boards, especially interposer substrates, are expected to become even thinner and coreless, so solder resists for PKG will need to have very good resolution.

  However, the object of the present invention is to overcome the above-mentioned problems, and to provide a photocurable resin composition that can be developed with an aqueous alkaline solution that has excellent resolution, excellent thermal shock resistance of the cured product, and excellent HAST resistance, and is less warped. It is in providing the photocurable dry film, hardened | cured material, and a printed wiring board containing them.

The above purpose is (A) alkali-soluble resin,
(B) a photopolymerization initiator, and (C) a spherical silica filler having an average particle size of 300 nm or less,
And (C) the amount of the spherical silica filler having an average particle diameter of 300 nm or less is 60% by mass or more based on the total amount of the photocurable resin composition. It has been found to be achieved with a photocurable resin composition that is developable with the aqueous alkaline solution characterized.

  In the photocurable resin composition of the present invention, the (A) alkali-soluble resin is preferably (A-1) a carboxyl group-containing resin having no photosensitive group.

  It is preferable that the photocurable resin composition of the present invention further includes (A-2) a carboxyl group-containing resin having a photosensitive group as the (A) alkali-soluble resin.

  It is preferable that the photocurable resin composition of the present invention further contains (D) an epoxy resin.

  In the photocurable resin composition of the present invention, the (D) epoxy resin is preferably an epoxy resin having a (D-1) naphthalene structure.

  In the photocurable resin composition of the present invention, (A-1) a polybasic acid anhydride is reacted with a polyalcohol resin obtained by modifying a polyphenol compound with an alkylene oxide as a carboxyl group-containing resin having no photosensitivity. It is preferable to use a carboxyl group-containing resin obtained by the above.

  In the photocurable resin composition of the present invention, (A-2) a photosensitive carboxyl group-containing resin is reacted with (meth) acrylic acid on a polyalcohol resin in which a polyphenol compound is alkyleneoside-modified, and further polybasic acid anhydride. It is preferable to use a carboxyl group-containing resin obtained by reacting.

  In addition, the object of the present invention is to provide a photocurable dry film obtained by applying and drying the photocurable resin composition of the present invention to a carrier film, or the photocurable resin composition or dry film as a carrier film. It solves with the hardened | cured material obtained by carrying out and photocuring, or a printed wiring board which has this hardened | cured material.

  According to the present invention, a photocurable resin that can be developed with an aqueous alkaline solution that has excellent thermal shock resistance and HAST resistance of a dry film and a cured product, has a low rate of warping of the cured product, and provides excellent resolution. A composition, a photocurable dry film obtained thereby, a cured product, and a printed wiring board including these are provided.

  In particular, in the present invention, since the silica filler has an average particle size of 300 nm and the silica filler is spherical, resolution is improved and warpage is reduced while suppressing cracks in the cured product. Moreover, the photocurable resin composition of the present invention can be cured even with a small exposure amount, and is excellent in energy efficiency.

The photocurable resin composition of the present invention can be developed with an aqueous alkaline solution,
(A) an alkali-soluble resin,
(B) a photopolymerization initiator, and (C) a spherical silica filler having an average particle size of 300 nm or less,
The amount of the spherical silica filler (C) having an average particle diameter of 300 nm or less is 60% by mass or more based on the total amount of the photocurable resin composition.

  Hereinafter, each component will be described.

[Component (A): Alkali-soluble resin]
The present invention uses an alkali-soluble resin. As the alkali-soluble resin, a carboxyl group-containing resin or a phenol resin is preferably used. In particular, use of a carboxyl group-containing resin is more preferable from the viewpoint of developability.

  As a carboxyl group-containing resin, various conventionally known carboxyl groups having a carboxyl group in the molecule and further having no ethylenically unsaturated double bond (non-photosensitive) or having (photosensitive) this Containing resins can be used.

  In particular, a non-photosensitive carboxyl group-containing resin having no ethylenically unsaturated double bond in the molecule is preferable from the viewpoint of improving flexibility, reducing warpage (low warpage), and improving crack resistance.

  Specific examples of the non-photosensitive carboxyl group-containing resin include the following compounds (any of oligomers and polymers).

  (1) Dialcohol compounds, polycarbonate-based polyols containing diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, and carboxyl groups such as dimethylolpropionic acid and dimethylolbutanoic acid, A carboxyl group-containing urethane resin by a polyaddition reaction of a diol compound such as a polyether polyol, polyester polyol, polyolefin polyol, bisphenol A alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

  (2) A carboxyl group-containing urethane resin by a polyaddition reaction of diisocyanate and a carboxyl group-containing dialcohol compound.

  (3) 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.

  (4) A dicarboxylic acid such as adipic acid, phthalic acid or hexahydrophthalic acid is reacted with a bifunctional epoxy resin or a bifunctional oxetane resin, and the resulting hydroxyl groups such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, etc. A carboxyl group-containing polyester resin to which a dibasic acid anhydride is added.

  (5) A carboxyl group-containing resin obtained by ring-opening an epoxy resin or an oxetane resin and reacting the generated hydroxyl group with a polybasic acid anhydride.

(6) A polybasic acid anhydride is added to a reaction product such as a polyalcohol resin obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule, that is, a polyphenol compound with an alkylene oxide such as ethylene oxide or propylene oxide. A carboxyl group-containing resin obtained by reacting.
In the present specification, (meth) acrylate means acrylate, methacrylate, and a mixture thereof.

  Among these, as the non-photosensitive carboxyl group-containing resin, it is preferable to use the above (1), (2), and (6) because they do not contain chlorine. Among them, it is preferable to use the above (6) that has an aromatic ring and is excellent in cold shock resistance and PCT resistance, and is well-balanced in all properties in combination with low warpage.

  Furthermore, it is preferable to add photosensitive carboxyl group-containing resin as an alkali-soluble resin to the resin composition of the present invention. Specific examples of the photosensitive carboxyl group-containing resin include the following compounds (any of oligomers and polymers). The ethylenically unsaturated double bond in the carboxyl group-containing resin is preferably derived from acrylic acid, methacrylic acid or derivatives thereof.

  (7) Dialcohol compounds, polycarbonate-based polyols containing diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, and carboxyl groups such as dimethylolpropionic acid and dimethylolbutanoic acid, Containing a carboxyl group by polyaddition reaction of a diol compound such as a polyether polyol, polyester polyol, polyolefin polyol, acrylic polyol, bisphenol A alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group Photosensitive urethane resin.

  (8) Diisocyanate and bifunctional epoxy resin 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, biphenol type epoxy resin ( A carboxyl group-containing photosensitive urethane resin obtained by a polyaddition reaction of (meth) acrylate or a partially acid anhydride modified product thereof with a carboxyl group-containing dialcohol compound.

  (9) During the synthesis of the resin described in (7) or (8) above, a compound having one hydroxyl group and one or more (meth) acryloyl groups in the molecule such as hydroxyalkyl (meth) acrylate is added, (Meth) acrylic carboxyl group-containing photosensitive urethane resin.

  (10) During the synthesis of the resin described in (8) or (9) above, one isocyanate group and one or more (meth) acryloyl groups in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate A carboxyl group-containing photosensitive urethane resin obtained by adding a compound having a terminal and being terminally (meth) acrylated.

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

  (12) A carboxyl obtained by reacting a polyfunctional epoxy resin obtained by epoxidizing a hydroxyl group of a bifunctional (solid) epoxy resin with epichlorohydrin with (meth) acrylic acid and adding a dibasic acid anhydride to the resulting hydroxyl group Group-containing photosensitive resin.

  (13) Two bases such as phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride are reacted with a difunctional acid such as adipic acid, phthalic acid, and hexahydrophthalic acid by reacting the bifunctional oxetane resin. A carboxyl group-containing polyester photosensitive resin to which an acid anhydride is added.

  (14) A compound having a plurality of phenolic hydroxyl groups in one molecule, that is, a reaction product such as a polyalcohol resin obtained by reacting a polyphenol compound with an alkylene oxide such as ethylene oxide or propylene oxide, and (meth) acrylic acid. A carboxyl group-containing photosensitive resin obtained by reacting an unsaturated group-containing monocarboxylic acid such as a polybasic acid anhydride with the resulting reaction product.

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

  (16) 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 (7) to (15) described above.

  As these photosensitive carboxyl group-containing resins, those other than those described as (7) to (16) can be used, and the types thereof may be used alone, or a plurality of types may be used in combination. In particular, a resin having an aromatic ring among the carboxyl group-containing resins is preferable because it not only has excellent resolution but also has excellent PCT and crack resistance.

  Among them, since carboxyl group-containing resins synthesized using a phenol compound as a starting material, such as carboxyl group-containing resins (14) and (15), do not contain chlorine, they have insulation properties such as HAST resistance and PCT resistance. In the present invention, it is excellent in toughness and, as a result, excellent in crack resistance.

  The above-mentioned carboxyl group-containing resin is the following regardless of whether it is photosensitive or non-photosensitive.

  That is, since it has many carboxyl groups in the side chain of the backbone polymer, development with a dilute alkaline aqueous solution becomes possible.

  The acid value of the carboxyl group-containing 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 carboxyl group-containing resin is less than 40 mgKOH / g, alkali development becomes difficult. On the other hand, when the acid value exceeds 200 mgKOH / g, dissolution of the exposed area by the developer proceeds and the line becomes thinner than necessary. Depending on the case, the exposed portion and the unexposed portion are not distinguished from each other by dissolution and peeling with a developer, which makes it difficult to draw a normal resist pattern.

  Moreover, although the weight average molecular weight of the above-mentioned carboxyl group-containing resin varies depending on the resin skeleton, it is generally preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. When the weight average molecular weight is less than 2,000, the tack-free performance may be inferior, the development resistance of the coated film after exposure may not be obtained, and the resolution may be greatly inferior. On the other hand, when the weight average molecular weight exceeds 150,000, developability may be remarkably deteriorated.

  The blending amount (solid content) of such a carboxyl group-containing resin is 10 to 60% by mass, preferably 20 to 50% by mass in the photocurable resin composition. When the blending amount of the carboxyl group-containing resin is less than 10% by mass, the film strength may be lowered, which is not preferable. On the other hand, when the amount is more than 60% by mass, the viscosity of the photocurable resin composition is increased, and applicability to a carrier film is decreased, which is not preferable.

  Further, when both a photosensitive carboxyl group-containing resin and a carboxyl group-containing resin having no photosensitivity are used, the content ratio of these is (photosensitive carboxyl group-containing resin: carboxyl group-containing resin having no photosensitivity) ), Based on the mass of the solid content, (1: 9) to (9: 1), preferably (2: 8) to (8: 2), more preferably (5: 5) to (7: 3) Scope. In this range, it is possible to obtain a cured product of a resin composition excellent in both resolution and low warpage and a printed wiring having the same while avoiding an increase in exposure amount.

  As the photosensitive carboxyl group-containing resin and the non-photosensitive carboxyl group-containing resin, those other than those described above can be used, and one kind of each may be used alone, or a plurality of kinds may be mixed and used. Also good. Among the carboxyl group-containing resins, in particular, a resin having an aromatic ring is preferable because it has a high refractive index and is excellent in resolution, and a resin having a novolak structure is further preferable in terms of resolution, PCT resistance, and It is excellent in terms of crack resistance and is preferable.

  Examples of the phenol resin include a compound having a phenolic hydroxyl group, such as a compound having a biphenyl skeleton or a phenylene skeleton, or both, or a phenolic hydroxyl group-containing compound such as 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 Further, phenol resins having various skeletons synthesized using trimethylhydroquinone, pyrogallol, phloroglucinol, or the like may be used.

  For example, phenol novolac resin, alkylphenol volac resin, bisphenol A novolac resin, dicyclopentadiene type phenol resin, Xylok type phenol resin, terpene modified phenol resin, polyvinylphenols, bisphenol F, bisphenol S type phenol resin, poly-p-hydroxy Known and commonly used phenol resins such as a condensate of styrene, naphthol and aldehydes, or a condensate of dihydroxynaphthalene and aldehydes can be used.

  These can be used alone or in combination of two or more.

  Commercially available products of such phenol resins include HF1H60 (Maywa Kasei Co., Ltd.) Phenolite TD-2090, Phenolite TD-2131 (Dai Nippon Printing Co., Ltd.), Vesmol CZ-256-A (Dic Co., Ltd.), Siyonor BRG- 555, Shionool BRG-556 (manufactured by Showa Denko), CGR-951 (manufactured by Maruzen Petroleum), or polyvinylphenol CST70, CST90, S-1P, S-2P (manufactured by Maruzen Petroleum) . These phenol resins can be used alone or in appropriate combination of two or more.

  In the present invention, any one of a carboxyl group-containing resin and a phenol resin, or a mixture thereof may be used as the alkali-soluble resin.

  In the photocurable resin composition of the present invention, when a material that does not contain an ethylenically unsaturated group is used as the alkali-soluble resin (component A), one or more, preferably two or more ethylene in the molecule. It is necessary to use a compound having a polymerizable unsaturated group, that is, a photopolymerizable monomer. The photopolymerizable monomer is photocured by active energy ray irradiation and promotes dissolution of the alkali-soluble resin in the aqueous alkali solution. In addition, when a carboxyl group-containing resin is used, a photopolymerizable monomer can be used in combination for the purpose of further promoting photocuring.

  In any case, one or more kinds of photopolymerizable monomers described later can be used.

[Component (B): Photopolymerization initiator]
In order to make the resin composition of this invention into a photocurable resin composition, a photoinitiator is mix | blended. The photopolymerization initiator includes at least one selected from the group consisting of an oxime ester photopolymerization initiator having an oxime ester group, an α-aminoacetophenone photopolymerization initiator, and an acylphosphine oxide photopolymerization initiator. Photoinitiators are preferred.

  Examples of the oxime ester photopolymerization initiator include CGI-325, Irgacure OXE01, Irgacure OXE02, ADEKA N-1919, and Adeka Arcles NCI-831 manufactured by BASF Japan. Moreover, the photoinitiator which has two oxime ester groups in a molecule | numerator can also be used suitably, Specifically, the oxime ester compound which has a carbazole structure represented with the following general formula is mentioned.

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

  In particular, in the above formula, X and Y are each a methyl group or an ethyl group, Z is methyl or phenyl, n is 0, and Ar is preferably phenylene, naphthylene, thiophene or thienylene.

  It is preferable that the compounding quantity of an oxime ester system photoinitiator shall be 0.01-5 mass parts with respect to 100 mass parts of carboxyl group-containing resin (solid content). When the amount is less than 0.01 parts by mass, the photocurability of the resin composition is insufficient, the coating film peels off, and the coating properties such as chemical resistance may deteriorate. On the other hand, when it exceeds 5 parts by mass, light absorption on the surface of the solder resist coating film becomes violent, and the deep curability tends to decrease. More preferably, it is 0.5-3 mass parts.

  As the α-aminoacetophenone photopolymerization initiator, specifically, 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 commercially available products include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by BASF Japan.

  Specific examples of the acylphosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and bis (2,6-dimethoxy). And benzoyl) -2,4,4-trimethyl-pentylphosphine oxide. Examples of commercially available products include Lucilin TPO and Irgacure 819 manufactured by BASF Japan.

  The blending amount of the α-aminoacetophenone photopolymerization initiator and the acylphosphine oxide photopolymerization initiator is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin (solid content). . If it is less than 0.1 parts by mass, the photocurability of the resin composition will be insufficient, and the coating film may be peeled off, and the coating properties such as chemical resistance may be deteriorated. On the other hand, when it exceeds 30 parts by mass, the effect of reducing the outgas cannot be obtained, the light absorption on the surface of the solder resist coating film becomes intense, and the deep curability tends to be lowered. More preferably, it is 0.5-15 mass parts.

  The resin composition of the present invention preferably uses an oxime ester photopolymerization initiator. By using an oxime ester photopolymerization initiator, sufficient sensitivity can be obtained even in a small amount, and since the photopolymerization initiator is less volatilized in the post-heating process at the time of thermal curing and mounting, Since shrinkage of the film can be suppressed, warping can be greatly reduced.

  It is also preferable to use an acylphosphine oxide photopolymerization initiator. Use of acylphosphine oxide improves the deep curability during photoreactions, and further incorporates an initiator-derived phosphorus-containing compound component cleaved by light irradiation into the cured product network, thereby improving the phosphorus concentration in the cured coating. It is possible to improve the flame retardancy further.

  In the resin composition of the present invention, it is effective to use either an oxime ester photopolymerization initiator or an acylphosphine oxide photopolymerization initiator. From the standpoints of improving accuracy and further improving low warpage, bendability, and flame retardancy, the combined use of an oxime ester photopolymerization initiator and an acylphosphine oxide photopolymerization initiator is more preferable.

  Further, as a photopolymerization initiator, Irgacure 389 and Irgacure 784 manufactured by BASF Japan can also be suitably used.

  In addition to the above-described photopolymerization initiator, a photoinitiator aid or a sensitizer can be used in the present invention.

[Photopolymerization initiation aid and sensitizer]
In addition, photoinitiators and sensitizers that can be suitably used in the resin composition of the present invention include benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, and xanthones. A compound etc. can be mentioned.

  Specific examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

  Specific examples of the acetophenone compound include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, and the like.

  Specific examples of the anthraquinone compound include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone, and the like.

  Specific examples of the thioxanthone compound include 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone.

  Specific examples of the ketal compound include acetophenone dimethyl ketal and benzyl dimethyl ketal.

  Specific examples of the benzophenone compound include benzophenone, 4-benzoyldiphenyl sulfide, 4-benzoyl-4′-methyldiphenyl sulfide, 4-benzoyl-4′-ethyldiphenyl sulfide, and 4-benzoyl-4′-propyldiphenyl. And sulfides.

  Specifically, as the tertiary amine compound, for example, an ethanolamine compound, a compound having a dialkylaminobenzene structure, for example, 4,4′-dimethylaminobenzophenone (Nisso Cure MABP manufactured by Nippon Soda Co., Ltd.), Dialkylaminobenzophenone such as 4,4′-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co., Ltd.), 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one (7- (diethylamino) -4- Dialkylamino group-containing coumarin compounds such as methylcoumarin), ethyl 4-dimethylaminobenzoate (Kayacure EPA manufactured by Nippon Kayaku Co., Ltd.), ethyl 2-dimethylaminobenzoate (Quantacure DMB manufactured by International Bio-Synthetics), 4- Methylaminobenzoic acid (n-butoxy) ethyl (Quantacure BEA manufactured by International Bio-Synthetics), p-dimethylaminobenzoic acid isoamylethyl ester (Nippon Kayaku Co., Ltd. Kayacure DMBI), 4-dimethylaminobenzoic acid 2 -Ethylhexyl (Esolol 507 manufactured by Van Dyk), 4,4'-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co., Ltd.) and the like.

  As the tertiary amine compound, a compound having a dialkylaminobenzene structure is preferable, and among them, a dialkylaminobenzophenone compound, a dialkylamino group-containing coumarin compound having a maximum absorption wavelength of 350 to 450 nm, and ketocoumarins are particularly preferable.

  As the dialkylaminobenzophenone compound, 4,4'-diethylaminobenzophenone is preferable because of its low toxicity. Dialkylamino group-containing coumarin compounds have a maximum absorption wavelength in the ultraviolet region of 350 to 410 nm, so they are less colored, and use colored pigments as well as colorless and transparent photosensitive compositions, and colors that reflect the color of the colored pigments themselves It becomes possible to provide a solder resist film. In particular, 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one is preferable because it exhibits an excellent sensitizing effect on laser light having a wavelength of 400 to 410 nm.

  As a compounding quantity of such a tertiary amine compound, it is preferable that it is 0.1-20 mass parts with respect to 100 mass parts (solid content) of carboxyl group-containing resin.

  When the amount of the tertiary amine compound is less than 0.1 parts by mass, a sufficient sensitizing effect tends not to be obtained. On the other hand, when the amount exceeds 20 parts by mass, light absorption on the surface of the dry solder resist coating film by the tertiary amine compound becomes intense, and the deep curability tends to decrease. More preferably, it is 0.1-10 mass parts.

  Of the above-described photoinitiators and sensitizers, thioxanthone compounds and tertiary amine compounds are preferred. In particular, it is preferable that a thioxanthone compound is contained from the viewpoint of deep part curability of the resin composition. Among them, it is preferable to include a thioxanthone compound such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone.

  As a compounding quantity of such a thioxanthone compound, it is preferable that it is 20 mass parts or less with respect to 100 mass parts of carboxyl group-containing resin (solid content). If the blending amount of the thioxanthone compound exceeds 20 parts by mass, the thick film curability may be lowered and the cost of the product may be increased. More preferably, it is 10 parts by mass or less.

  These photoinitiation assistants and sensitizers may be used alone or as a mixture of two or more.

  The total amount of the above-mentioned photopolymerization initiator, photoinitiator assistant, and sensitizer is 35 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing resin in the photosensitive resin composition for printed wiring boards capable of alkali development. Preferably there is. When it exceeds 35 parts by mass, the deep curability of the resin composition tends to decrease due to these light absorptions.

  In addition, since the above-mentioned photoinitiator, photoinitiator assistant, and sensitizer absorb a specific wavelength, in some cases, the sensitivity is lowered, and the photoinitiator, the photoinitiator, and the sensitizer may function as an ultraviolet absorber. However, they are not used only for the purpose of improving the sensitivity of the composition. Absorbs light of a specific wavelength as necessary to enhance the photoreactivity of the surface, and changes the resist line shape and opening to vertical, tapered, and inversely tapered, and processing accuracy of line width and opening diameter Can be improved.

[Component C: Spherical silica filler having an average particle size of 300 nm or less]
In the resin composition of the present invention, a spherical silica filler having an average particle size of 300 nm or less (hereinafter also referred to as spherical nano silica) is used. Preferably it is 200 nm or less, and 3 nm or more is preferable as a minimum. The average particle diameter is measured by a laser diffraction method.

  The spherical nanosilica used in the present invention is preferably one whose surface is treated with a silane coupling agent. This can prevent precipitation and aggregation after being dispersed in the liquid, and as a result, the storage stability is excellent. In addition, the composition can be stably fed without agglomeration. Furthermore, the wettability between the resin and filler of the obtained cured product can be improved.

  Examples of the organic group contained in the silane coupling agent include a vinyl group, an epoxy group, a styryl group, a methacryloxy group, an acryloxy group, an amino group, a ureido group, a chloropropyl group, a mercapto group, a polysulfide group, and an isocyanate group. Is mentioned.

  Examples of commercially available silane coupling agents include KA-1003, KBM-1003, KBE-1003, KBM-303, KBM-403, KBE-402, KBE-403, KBM-1403, KBM-502, KBM. -503, KBE-502, KBE-503, KBM-5103, KBM-602, KBM-603, KBE-603, KBM-903, KBE-903, KBE-9103, KBM-9103, KBM-573, KBM-575 , KBM-6123, KBE-585, KBM-703, KBM-802, KBM-803, KBE-846, KBE-9007 (all trade names; manufactured by Shin-Etsu Silicone). These may be used alone or in combination of two or more.

The spherical nano silica of the present invention may be used alone or in combination of two or more, and may be used in combination with other fillers as described later.
In the present invention, the resolution of the resin composition can be greatly improved by using spherical nano silica.

  The spherical nanosilica component in the photocurable resin composition can be a starting point for scattering light, and the light scattering greatly affects the resolution. It can be inferred that the light scattering phenomenon depends on the particle diameter of the nano silica particles from theories such as Rayleigh scattering and Mie scattering. This is because, in the Mie scattering formula, the light scattering intensity increases as the size parameter of the scatterer increases. Further, when the size parameter is sufficiently small with respect to the wavelength of light, the scattering intensity becomes small.

  Therefore, light scattering can be suppressed by making the size of the spherical nanosilica smaller than the wavelength of light used for exposure, and in the present invention, a photocurable resin composition having excellent resolution can be obtained.

  The spherical nanosilica of the present invention has good dispersibility in the resin, and since it is spherical, the occurrence of cracks in the cured film is reduced well. Furthermore, even if the filling is high, the occurrence of warpage can be reduced, and the effect of improving the bending resistance can be expected.

  Examples of other types of fillers that can be used in combination with spherical nanosilica include spherical silica fillers with an average particle size exceeding 300 nm, and other conventional inorganic or organic fillers, especially alumina, barium sulfate, talc, and Neuburg silica particles. is there. Furthermore, aluminum hydroxide, magnesium hydroxide, boehmite, or the like can be used as a filler capable of imparting flame retardancy.

Moreover, the spherical nano silica used in the present invention may be spherical and is not limited to a true sphere. Examples of suitable component (C) include those having a sphericity measured as follows of 0.8 or more.
The sphericity is measured as follows. A photograph is taken with an SEM, and is calculated as a value calculated by (sphericity) = {4π × (area) ÷ (perimeter) 2} from the area and perimeter of the observed particle. Specifically, an average value measured for 100 particles using an image processing apparatus is employed.

  The method for producing the spherical silica particles is not particularly limited, and methods known to those skilled in the art can be applied. For example, it can be manufactured by burning silicon powder by a VMC (Vap-erized Metal Combustion) method. In the VMC method, a chemical flame is formed by a burner in an oxygen-containing atmosphere, and metal powder that constitutes part of the target oxide particles is introduced into the chemical flame in such an amount that a dust cloud is formed. In this method, deflagration is caused to obtain oxide particles.

  The blending amount of the spherical nano silica in the resin composition of the present invention is preferably 60% by mass or more, more preferably more than 70% by mass, particularly preferably 70% by mass in the entire composition (the alkali availability resin is converted as a solid content). % Over 85% by mass. When the amount of the spherical nano silica is less than 60% by mass, the viscosity of the curable resin composition is lowered, and there is a possibility that the printability may be lowered or the curability of the cured product may be reduced.

  Other fillers can be added so that the spherical silica filler (component B) of the present invention accounts for 50% by mass or more, preferably 80% by mass or more based on the total amount of the filler.

  The amount of nanosilica blended can be clarified by measuring the amount of residue after combustion. Specifically, it can be measured by TG-DTA (manufactured by Hitachi High-Tech Science Co., Ltd.) in which the combustion conditions are set to 800 to 1000 ° C.

  Furthermore, NANOCRYL (trade names) XP 0396, XP 0596, XP 0733, XP 0746, XP 0765, manufactured by Hanse-Chemie, in which nano silica is dispersed in a compound having one or more ethylenically unsaturated groups or a polyfunctional epoxy resin, XP 0768, XP 0953, XP 0954, XP 1045 (all product grade names) and NANOPOX (trade name) XP 0516, XP 0525, XP 0314 (all product grade names) manufactured by Hanse-Chemie can also be used. In this case as well, the total amount of the nanosilica compounded amount and the other compounded filler is the same as described above.

[Photopolymerizable monomer]
The photocurable resin composition of the present invention may contain a known and commonly used photoreactive monomer. The photopolymerizable monomer is a compound having one or more ethylenically unsaturated groups in the molecule. The photoreactive monomer assists photocuring of the carboxyl group-containing resin by irradiation with active energy rays.

  Examples of the compound used as the photopolymerizable monomer include conventionally known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, and epoxy (meth) acrylate. It is done. Specifically, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; N, N-dimethylacrylamide Acrylamides such as N-methylol acrylamide and N, N-dimethylaminopropyl acrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate; hexanediol, trimethylolpropane, Polyhydric alcohols such as pentaerythritol, dipentaerythritol, tris-hydroxyethyl isocyanurate or the like; Multivalent acrylates such as a peroxide adduct, a propylene oxide adduct, or an ε-caprolactone adduct; a polyvalent such as phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adduct or propylene oxide adduct of these phenols Acrylates; glyceryl diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyglycerides of glycidyl ether such as triglycidyl isocyanurate; not limited to the above, polyether polyol, polycarbonate diol, hydroxyl-terminated polybutadiene, Polyacrylate polyol and other polyols are directly acrylated or urethane acrylated via diisocyanate Acrylates and melamine acrylates, and at least one of each methacrylate corresponding to the acrylate.

  Among these, the use of a photopolymerizable monomer having an aromatic ring is preferable in terms of reduction in warpage.

  Further, an epoxy acrylate resin obtained by reacting acrylic acid with a polyfunctional epoxy resin such as a cresol novolac type epoxy resin, or a hydroxy acrylate such as pentaerythritol triacrylate and a diisocyanate such as isophorone diisocyanate on the hydroxyl group of the epoxy acrylate resin. An epoxy urethane acrylate compound obtained by reacting a half urethane compound may be used as a photoreactive monomer. Such an epoxy acrylate resin can improve photocurability without deteriorating the touch drying property.

  The blending amount of the photopolymerizable monomer is 5 to 100 parts by mass, more preferably 5 to 100 parts by mass (solid content) of the photosensitive carboxyl group-containing resin and the non-photosensitive carboxyl-containing resin. The ratio is 70 parts by mass.

  When the blending amount is less than 5 parts by mass, the photocurability is lowered, and pattern development may be difficult due to alkali development after irradiation with active energy rays. On the other hand, when the amount exceeds 100 parts by mass, the solubility in an aqueous alkali solution is lowered, and the coating film may become brittle.

[Thermosetting component]
In addition to photocuring, the photocurable resin composition of the present invention can be further thermally cured.

  By further thermosetting the resin composition after photocuring, it is possible to improve properties such as heat resistance and insulation reliability of the cured product.

  As thermosetting components, known and commonly used thermosetting resins such as isocyanate compounds, blocked isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, polyfunctional oxetane compounds, episulfide resins, etc. Can be used.

  In the present invention, epoxy resin (D) is particularly preferably used.

  As the epoxy resin, a known and commonly used polyfunctional epoxy resin having at least two epoxy groups in one molecule can be used. The epoxy resin may be liquid, and may be solid or semi-solid.

  As the epoxy resin, for example, jER828, jER834, jER1001, jER1004 manufactured by Mitsubishi Chemical Corporation, Epicron 840, Epicron 850, Epicron 1050, Epicron 2055, Epoto YD-011, YD-013 manufactured by Tohto Kasei Co., Ltd. YD-127, YD-128, D.C. E. R. 317, D.E. E. R. 331, D.D. E. R. 661, D.D. E. R. 664, Sumitomo Epoxy ESA-011, ESA-014, ELA-115, ELA-128, manufactured by Sumitomo Chemical Co., Ltd., A.A. E. R. 330, A.I. E. R. 331, A.I. E. R. 661, A.I. E. R. Bisphenol A type epoxy resin such as 664 (all trade names); jERYL903 manufactured by Mitsubishi Chemical, Epicron 152, Epicron 165 manufactured by DIC, Epototo YDB-400, YDB-500 manufactured by Tohto Kasei Co., Ltd., manufactured by Dow Chemical Of D. E. R. 542, Sumitomo Epoxy ESB-400, ESB-700 manufactured by Sumitomo Chemical Co., Ltd., A.A. E. R. 711, A.I. E. R. Brominated epoxy resins such as 714 (both trade names); jER152 and jER154 manufactured by Mitsubishi Chemical Corporation, and D.C. E. N. 431, D.D. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865 manufactured by DIC, Epototo YDCN-701, YDCN-704 manufactured by Tohto Kasei Co., Ltd., EPPN-201, EOCN-1025, EOCN manufactured by Nippon Kayaku Co., Ltd. -1020, EOCN-104S, RE-306, NC-3000, Sumitomo Epoxy ESCN-195X, ESCN-220, manufactured by Sumitomo Chemical Co., Ltd., A.C. E. R. ECN-235, ECN-299, YDCN-700-2, YDCN-700-3, YDCN-700-5, YDCN-700-7, YDCN-700-10, YDCN-704 YDCN- manufactured by Nippon Steel Chemical Co., Ltd. Novolak type epoxy resins such as 704A, Epicron N-680, N-690, N-695 (all trade names) manufactured by DIC; Epicron 830 manufactured by DIC, jER807 manufactured by Mitsubishi Chemical Co., Ltd. Bisphenol F type epoxy resin such as YDF-170, YDF-175, YDF-2004, etc. (all trade names); Hydrogenation of Epototo ST-2004, ST-2007, ST-3000 (trade names) manufactured by Toto Kasei Co., Ltd. Bisphenol A type epoxy resin; jER604 manufactured by Mitsubishi Chemical Corporation, Epototo YH-434 manufactured by Toto Kasei Co., Ltd. Glycidylamine type epoxy resin such as Sumi-epoxy ELM-120 manufactured by Sumitomo Chemical Co., Ltd. (all trade names); Hydantoin type epoxy resin; Celoxide 2021 manufactured by Daicel Chemical Industries Ltd. Epoxy resin: YL-933 manufactured by Mitsubishi Chemical Co., Ltd. E. N. , EPPN-501, EPPN-502, etc. (all trade names) trihydroxyphenylmethane type epoxy resin; Mitsubishi Chemical Corporation YL-6056, YX-4000, YL-6121 (all trade names) Type or biphenol type epoxy resin or a mixture thereof; Nippon Kayaku EBPS-200, ADEKA EPX-30, DIC EXA-1514 (trade name) and other bisphenol S type epoxy resins; Bisphenol A novolac type epoxy resin such as jER157S (trade name); tetraphenylolethane type epoxy resin such as jERYL-931 (all trade name) made by Mitsubishi Chemical; TEPIC made by Nissan Chemical Industries (all) Product name) heterocyclic epoxy resin; Niguri such as Bremer DGT manufactured by NOF Corporation Zylphthalate resin; Tetraglycidylxylenoylethane resin such as ZX-1063 manufactured by Tohto Kasei; ESN-190, ESN-360 manufactured by Nippon Steel Chemical Co., Ltd., HP-4032, EXA-4750, EXA-4700 manufactured by DIC Naphthalene group-containing epoxy resin; epoxy resin having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by DIC; glycidyl methacrylate copolymer epoxy resin such as CP-50S and CP-50M manufactured by NOF Corporation; Further, a copolymerized epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; a CTBN-modified epoxy resin (for example, YR-102, YR-450, etc., manufactured by Tohto Kasei Co., Ltd.), and the like, are not limited thereto.

  These epoxy resins may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the present invention, an epoxy resin (component D-1) having a naphthalene structure is particularly preferably used among the epoxy resins. By using an epoxy resin having a naphthalene structure, the low warpage and flame retardancy of the cured product are improved.

  Specific examples of commercially available materials include ESN-190, ESN-360 (manufactured by Nippon Steel Chemical Co., Ltd.), HP-4032, EXA-4750, and EXA-4700 (manufactured by DIC).

  These curable resins may be used alone or in combination of two or more. By using an epoxy resin having a naphthalene structure, the flexibility of the cured coating film and the linear expansion coefficient can be reduced.

  The compounding amount of the thermosetting component is 5 to 50 parts by mass, preferably 10 to 30 parts per 100 parts by mass (solid content) of the photosensitive carboxyl group-containing resin and the non-photosensitive carboxyl-containing resin. It is a ratio of parts by mass.

  Furthermore, the photocurable resin composition of the present invention uses an additive such as a colorant, a predetermined copolymer, a binder polymer, an elastomer, an adhesion promoter, an antioxidant, and an ultraviolet absorber, and an organic solvent. Can be configured. These components will be described below.

[Colorant]
A coloring agent can be mix | blended with the curable resin composition of this invention.

  As the colorant, conventionally known colorants such as red, blue, green and yellow can be used, and any of pigments, dyes and dyes may be used. Specific examples include those with the following color index numbers (CI: issued by The Society of Dyer's and Colorists). However, it is preferable that the colorant does not contain a halogen from the viewpoint of reducing environmental burden and affecting the human body.

Red colorant:
Examples of red colorants include monoazo, diazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone. It is done.

  Monoazo: Pigment Red 1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31,32, 112, 114, 146, 147, 151 , 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267,268, 269.

  Disazo: Pigment Red 37, 38, 41.

  Monoazo lakes: Pigment Red 48: 1, 48: 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2,53: 1, 53: 2, 57 : 1, 58: 4, 63: 1, 63: 2, 64: 1,68.

  Benzimidazolone series: Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185, Pigment Red 208.

  Perylene series: Solvent Red 135, Solvent Red 179, Pigment Red 123, Pigment Red 149, Pigment Red 166, Pigment Red 178, Pigment Red 179, Pigment Red 190, Pigment Red 194, Pigment Red 224.

  Diketopyrrolopyrrole series: Pigment Red 254, Pigment Red 255, Pigment Red 264, Pigment Red 270, Pigment Red 272.

  Condensed azo series: Pigment Red 220, Pigment Red 144, Pigment Red 166, Pigment Red 214, Pigment Red 220, Pigment Red 221 and Pigment Red 242.

  Anthraquinone series: Pigment Red 168, Pigment Red 177, Pigment Red 216, Solvent Red 149, Solvent Red 150, Solvent Red 52, Solvent Red 207.

Kinacridone series: Pigment Red 122, Pigment Red 202, Pigment Red 206, Pigment Red
207, Pigment Red 209.

Blue colorant:
Blue colorants include phthalocyanine and anthraquinone, and pigments are compounds classified as Pigment, specifically: Pigment Blue 15, Pigment Blue 15: 1, Pigment Blue 15: 2, Pigment Blue 15: 3, Pigment Blue 15: 4, Pigment Blue 15: 6, Pigment Blue 16, Pigment Blue 60.

  The dye systems include Solvent Blue 35, Solvent Blue 63, Solvent Blue 68, Solvent Blue 70, Solvent Blue 83, Solvent Blue 87, Solvent Blue 94, Solvent Blue 97, Solvent Blue 122, Solvent Blue 136, Solvent Blue 67, Solvent Blue 70 etc. can be used. In addition to the above, a metal-substituted or unsubstituted phthalocyanine compound can also be used.

Green colorant:
Similarly, green colorants include phthalocyanine, anthraquinone, and perylene. Specifically, Pigment Green 7, Pigment Green 36, Solvent Green 3, Solvent Green 5, Solvent Green 20, Solvent Green 28, etc. are used. be able to. In addition to the above, a metal-substituted or unsubstituted phthalocyanine compound can also be used.

Yellow colorant:
Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, anthraquinone, and the like.

  Anthraquinone series: Solvent Yellow 163, Pigment Yellow 24, Pigment Yellow 108, Pigment Yellow 193, Pigment Yellow 147, Pigment Yellow 199, Pigment Yellow 202.

  Isoindolinone type: Pigment Yellow 110, Pigment Yellow 109, Pigment Yellow 139, Pigment Yellow 179, Pigment Yellow 185.

  Condensed azo series: Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 95, Pigment Yellow 128, Pigment Yellow 155, Pigment Yellow 166, Pigment Yellow 180.

  Benzimidazolone series: Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 156, Pigment Yellow 175, Pigment Yellow 181.

  Monoazo: Pigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62: 1, 65, 73, 74,75, 97, 100, 104, 105, 111, 116 , 167, 168, 169, 182, 183.

  Disazo type: Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152,170, 172, 174, 176, 188, 198.

  In addition, a colorant such as purple, orange, brown, or black may be added for the purpose of adjusting the color tone.

  For example, Pigment Violet 19, 23, 29, 32, 36, 38, 42, Solvent Violet 13, 36, CI Pigment Orange 1, CI Pigment Orange 5, CI Pigment Orange 13, CI Pigment Orange 14, CI Pigment Orange 16, CI Pigment Orange 17, CI Pigment Orange 24, CI Pigment Orange 34, CI Pigment Orange 36, CI Pigment Orange 38, CI Pigment Orange 40, CI Pigment Orange 43, CI Pigment Orange 46, CI Pigment Orange 49, CI Pigment Orange 51, CI Pigment Orange 61, CI Pigment Orange 63, CI Pigment Orange 64, CI Pigment Orange 71, CI Pigment Orange 73, CI Pigment Brown 23, CI Pigment Brown 25, CI Pigment Blue Rack 1, C.I. Pigment Black 7, etc.

  Although there is no restriction | limiting in particular in the mixture ratio of a coloring agent, Preferably it is 0-10 mass parts with respect to a total of 100 mass parts (solid content) of photosensitive carboxyl group-containing resin and non-photosensitive carboxyl-containing resin, Preferably Is used at a ratio of 0.1 to 5 parts by mass.

[Binder polymer]
For the resin composition of the present invention, conventionally known binder polymers can be used for the purpose of improving the flexibility and dryness of the touch of the resulting cured product.
As the binder polymer, a cellulose-based, polyester-based, or phenoxy resin-based polymer is preferably used.

As cellulose polymer, Eastman cellulose acetate butyrate (CAB), cellulose acetate propionate (CAP) series,
Byron series manufactured by Toyobo Co., Ltd.
As the phenoxy resin polymer, bisphenol A, bisphenol F, and phenoxy resins of hydrogenated compounds thereof are preferable.

  The addition amount of the binder polymer is preferably 50 parts by mass or less, more preferably 1 to 30 parts by mass, particularly preferably relative to 100 parts by mass in total of the photosensitive carboxyl group-containing resin and the non-photosensitive carboxyl-containing resin. Is 5-30 parts by mass. When the amount of the binder polymer exceeds 50 parts by mass, the alkali developability of the curable resin composition is inferior, and the usable potable time for development may be shortened.

[Y-X-Y type block copolymer]
The photocurable resin composition of this invention can use a block copolymer together. The block copolymer generally means a copolymer having a molecular structure in which two or more kinds of polymer units having different properties are connected by a covalent bond to form a long chain.

  By using a YXY block copolymer in combination with a spherical silica filler having an average particle size of 300 nm or less, the cured product obtained from the photocurable resin composition of the present invention can be used while suppressing cracks. The image quality is further improved and the warp property is further reduced.

The block copolymer used in the present invention has the following formula (I),
Y-X-Y (I)
(In the formula, Y is a polymer unit having a glass transition point Tg of 0 ° C. or more, preferably 50 ° C. or more, and X is a polymer unit having a glass transition point Tg of less than 0 ° C., preferably −20 ° C. or less.) It is preferable that it is a block copolymer represented by these, Furthermore, it is preferable that it is a solid at 20 degreeC or more and 30 degrees C or less.

  Thus, it is considered that a specific structure in the matrix can be easily shown by using a block copolymer in which the blocks at both ends are compatible with the matrix and the central block is incompatible with the matrix.

  The polymer unit Y is preferably polymethyl methacrylate (PMMA), polystyrene (PS) or the like, and the polymer unit X is preferably poly n-butyl acrylate (PBA) or polybutadiene (PB). Moreover, hydrophilicity excellent in compatibility with the above-described carboxyl group-containing resins represented by the styrene unit, hydroxyl group-containing unit, carboxyl group-containing unit, epoxy-containing unit, N-substituted acrylamide unit, etc. as part of the polymer unit Y When the unit is introduced, the compatibility can be further improved.

  Examples of the method for producing the block copolymer include the methods described in Japanese Patent Application Nos. 2005-515281 and 2007-516326.

Specifically, in formula (I),
Y is polystyrene, polyglycidyl methacrylate, N-substituted polyacrylamide, polymethyl (meth) acrylate, carboxylic acid modified product or hydrophilic group modified product thereof, and X is poly n-butyl (meth) acrylate or polybutadiene, etc. Is preferred.

  As a commercial item of a YXY type block copolymer, the acryl-type triblock copolymer manufactured using the living polymerization made from Arkema is mentioned. Specific examples include MAM types represented by polymethyl methacrylate-polybutyl acrylate-polymethyl methacrylate (for example, M51, M52, M53, M22, etc.), MAM A type modified with carboxylic acid (for example, SM4032XM10, etc.) And MAM N type (for example, 52N, 22N, etc.) subjected to hydrophilic group modification treatment.

  Moreover, the mass average molecular weight (Mw) of a block copolymer is 20000 or more and 400,000 or less, and the thing in the range of 30,000-300,000 is preferable. The molecular weight distribution (Mw / Mn) is preferably 3 or less.

  When the mass average molecular weight is less than 20,000, the effects of toughness and flexibility cannot be obtained, and the tackiness is also inferior. On the other hand, when the mass average molecular weight exceeds 400,000, the viscosity of the curable resin composition increases, and the printability, developability, and the like are significantly deteriorated.

  The blending amount of the block copolymer is preferably in the range of 1 to 50 parts by mass, more preferably 5 to 35 parts by mass with respect to 100 parts by mass (solid content) of the (A) carboxyl group-containing resin.

  If it is less than 1 part by mass, the effect is not expected, and if it is 50 parts by mass or more, the photocurable resin composition is unfavorable because developability and applicability may be deteriorated.

[Elastomer]
The resin composition of the present invention can be blended with an elastomer for the purpose of imparting flexibility to the resulting cured product and improving the brittleness of the cured product.

  Examples of the elastomer include polyester elastomers, polyurethane elastomers, polyester urethane elastomers, polyamide elastomers, polyesteramide elastomers, acrylic elastomers, and olefin elastomers.

  In addition, a resin in which a part or all of epoxy groups of epoxy resins having various skeletons are modified with a carboxylic acid-modified butadiene-acrylonitrile rubber at both ends can be used.

  Furthermore, epoxy-containing polybutadiene elastomers, acrylic-containing polybutadiene elastomers, hydroxyl group-containing polybutadiene elastomers, hydroxyl group-containing isoprene elastomers and the like can also be used.

  One type of elastomer may be used alone, or a mixture of two or more types may be used.

[Adhesion promoter]
In the resin composition of the present invention, an adhesion promoter can be used in order to improve adhesion between layers or adhesion between the photosensitive resin layer and the substrate.

  Examples of the adhesion promoter include benzimidazole, benzoxazole, benzthiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzthiazole, 3-morpholinomethyl-1-phenyl-triazole-2-thione, List 5-amino-3-morpholinomethyl-thiazole-2-thione, 2-mercapto-5-methylthio-thiadiazole, triazole, tetrazole, benzotriazole, carboxybenzotriazole, amino group-containing benzotriazole, silane coupling agent, etc. Can do.

[Antioxidant]
In many polymer materials, once oxidation starts, oxidative degradation occurs one after another in a chain, resulting in a decrease in the function of the polymer material. In the resin composition of the present invention, (1) a radical scavenger that invalidates the generated radical and (2) the generated peroxide is decomposed into a harmless substance so that no new radical is generated. At least one of antioxidants such as a peroxide decomposing agent can be added.

  Specific examples of the radical scavenger include hydroquinone, 4-tert-butylcatechol, 2-t-butylhydroquinone, hydroquinone monomethyl ether, 2,6-di-t-butyl-p-cresol, 2,2-methylene-bis- (4-methyl- 6-t-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3 5-di-t-butyl-4-hydroxybenzyl) benzene, 1,3,5-tris (3 ′, 5′di-t-butyl-4-hydroxybenzyl) -S-triazine-2,4,6- Phenolic compounds such as (1H, 3H, 5H) trione, quinone compounds such as metaquinone and benzoquinone, bis (2,2,6,6-tetramethyl-4-piperidyl - sebacate, and the like amine compounds such as phenothiazine.

  The radical scavenger may be commercially available, for example, ADK STAB AO-30, ADK STAB AO-330, ADK STAB AO-20, ADK STAB LA-77, ADK STAB LA-57, ADK STAB LA-67, ADK STAB LA-68, ADK STAB LA-87 (above, manufactured by Asahi Denka Co., Ltd., trade name), IRGANOX 1010, IRGANOX 1035, IRGANOX 1076, IRGANOX 1135, TINUVIN 111FDL, TINUVIN 123, TINUVIN 144, TINUVIN 152, TINUVIN 292, TINUVS 5100 Japan, TINUVIN 5F Japan, Name).

  Specific examples of the antioxidant that acts as a peroxide decomposer include phosphorus compounds such as triphenyl phosphite, pentaerythritol tetralauryl thiopropionate, dilauryl thiodipropionate, distearyl 3,3 ′. -Sulfur compounds such as thiodipropionate.

  The peroxide decomposing agent may be a commercially available one. For example, ADK STAB TPP (manufactured by Asahi Denka Co., Ltd., trade name), Mark AO-412S (manufactured by Adeka Argus Chemical Co., trade name), Sumilyzer TPS (manufactured by Sumitomo Chemical) , Product name).

  An antioxidant may be used individually by 1 type and may be used in combination of 2 or more type.

[Ultraviolet absorber]
Since the polymer material absorbs light and thereby decomposes and deteriorates, the resin composition of the present invention uses an ultraviolet absorber in addition to the antioxidant in order to take a countermeasure against stabilization against ultraviolet rays. Can do.

  Examples of the ultraviolet absorber include benzophenone derivatives, benzoate derivatives, benzotriazole derivatives, triazine derivatives, benzothiazole derivatives, cinnamate derivatives, anthranilate derivatives, dibenzoylmethane derivatives, and the like.

Specific examples of benzophenone derivatives include 2-hydroxy-4-methoxy-benzophenone 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone and 2,4-dihydroxybenzophenone, etc.
Specific examples of benzoate derivatives include 2-ethylhexyl salicylate, phenyl salicylate, pt-butylphenyl salicylate, 2,4-di-t-butylphenyl-3,5-di-t-butyl. -4-hydroxybenzoate and hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate,
Specific examples of the benzotriazole derivative include 2- (2′-hydroxy-5′-t-butylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) enzotriazole, 2- (2 ′ -Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-amylphenyl) benzotriazole, and the like,
Specific examples of the triazine derivative include hydroxyphenyl triazine, bisethylhexyloxyphenol methoxyphenyl triazine, and the like.

  Ultraviolet absorbers may be commercially available, for example, TINUVIN PS, TINUVIN 99-2, TINUVIN 109, TINUVIN 384-2, TINUVIN 900, TINUVIN 928, TINUVIN 1130, TINUVIN 400, TINUVIN 405, TINUVIN 460, TINUVIN 479 (above, manufactured by BASF Japan Ltd., trade name).

  An ultraviolet absorber may be used individually by 1 type, and can also be used in combination of 2 or more type. By using in combination with an antioxidant, the molded product obtained from the curable resin composition of the present invention can be stabilized.

[Other additives]
In the resin composition of the present invention, additives such as a thermal polymerization inhibitor, a thickener, an antifoaming agent, a leveling agent, a silane coupling agent, and a rust preventive can be used as necessary.

Among these, as thermal polymerization inhibitors, hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol, phenothiazine, etc.
As a thickener, fine silica, organic bentonite, montmorillonite, etc.
As at least one of the antifoaming agent and the leveling agent, silicone-based, fluorine-based, polymer-based, etc.
As the silane coupling agent, imidazole, thiazole, triazole and the like can be used. Additives can be blended.

  The thermal polymerization inhibitor can be used to prevent unintentional thermal polymerization or temporal polymerization of the resin composition.

  Examples of the thermal polymerization inhibitor include 4-methoxyphenol, hydroquinone, alkyl or aryl-substituted hydroquinone, t-butylcatechol, pyrogallol, 2-hydroxybenzophenone, 4-methoxy-2-hydroxybenzophenone, cuprous chloride, phenothiazine, Chloranil, naphthylamine, β-naphthol, 2,6-di-tert-butyl-4-cresol, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), pyridine, nitrobenzene, dinitrobenzene, picric acid, 4-Toluidine, methylene blue, copper and organic chelating agent reactant, methyl salicylate, and phenothiazine, nitroso compound, chelate of nitroso compound and Al, and the like.

[Organic solvent]
Furthermore, an organic solvent can be used in the present invention. The organic solvent is a synthesis of a carboxyl group-containing resin, components A to C, optionally components D, E, F, and necessary additives, and the obtained photosensitive resin composition is applied to a substrate or a carrier film. It is used for viscosity adjustment.

  Examples of the organic solvent include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like.

More specifically, ketones such as methyl ethyl ketone and cyclohexanone,
Aromatic hydrocarbons such as toluene, xylene, tetramethylbenzene,
Cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, glycol ethers such as propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether,
Esters such as ethyl acetate, butyl acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate,
Alcohols such as ethanol, propanol, ethylene glycol, propylene glycol,
Aliphatic hydrocarbons such as octane and decane,
Examples thereof include petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

  Such an organic solvent may be used individually by 1 type, and may be used as a 2 or more types of mixture.

  The curable resin composition of this invention can also be made into the form of the dry film provided with the layer which consists of a carrier film (support body) and the curable resin composition formed on this carrier film.

  In forming a dry film, the curable resin composition of the present invention is diluted with an organic solvent to adjust to an appropriate viscosity, a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, a transfer roll coater, A film can be obtained by applying a uniform thickness on a carrier film with a gravure coater, spray coater or the like, and usually drying at a temperature of 50 to 130 ° C. for 1 to 30 minutes. Although there is no restriction | limiting in particular about a coating film thickness, Generally, it is 10-150 micrometers by the film thickness after drying, Preferably it selects suitably in the range of 20-60 micrometers.

  As the carrier film, a plastic film is used, 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 composition of the present invention is formed on the carrier film, it is preferable to laminate a peelable cover film on the surface of the film for the purpose of preventing dust from adhering to the surface of the film.

  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. In consideration of peeling of the cover film, the adhesive force between the membrane and the cover film is made smaller than the adhesive force between the membrane and the carrier film.

  The resin composition of the present invention is adjusted to a viscosity suitable for a coating method using, for example, an organic solvent, and on a substrate, a dip coating method, a flow coating method, a roll coating method, a bar coater method, a screen printing method, a curtain coating method. A tack-free coating film can be formed by applying the organic solvent contained in the composition at a temperature of about 60 to 100 ° C. and performing volatile drying (temporary drying). In the case of a dry film obtained by applying the composition on a carrier film and drying and winding it as a film, after laminating the photocurable resin composition layer on the base material so as to contact the base material The resin insulating layer can be formed by peeling off the carrier film.

  In addition to printed circuit boards and flexible printed circuit boards that are pre-formed on the circuit board, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, glass cloth / paper epoxy, synthetic fiber epoxy , Copper-clad laminates of all grades (FR-4 etc.) and other polyimide films using materials such as copper-clad laminates for high-frequency circuits using fluorine, polyethylene, polyphenylene ether, polyphenylene oxide, cyanate esters, etc. , PET film, glass substrate, ceramic substrate, wafer plate and the like.

  Volatile drying performed after applying the photo-curable resin composition of the present invention is performed in a dryer using a hot air circulation drying furnace, an IR furnace, a hot plate, a convection oven or the like (equipped with an air heating heat source using steam). It is possible to use a method in which hot air is brought into countercurrent contact and a method in which a hot air is blown onto a support.

  In this invention, the solvent of a photocurable resin composition or a dry film is volatilized and dried, and exposure (irradiation of active energy rays) is performed on the coating film obtained thereby, thereby exposing parts (by active energy rays). The irradiated part is cured.

  For example, the photocurable resin composition or dry film after drying can be exposed with an active energy ray through a photomask having a pattern formed by a contact method or a non-contact method. In addition, the exposed part can be photocured by directly pattern-exposing the photocurable resin composition or the dry film with a laser direct exposure machine.

  In any of the above methods, a resist pattern can be formed by developing an unexposed portion with a dilute alkaline aqueous solution (for example, a 0.3 to 3 wt% sodium carbonate aqueous solution).

  As an exposure machine used for active energy ray irradiation, a high-pressure mercury lamp lamp, an ultra-high pressure mercury lamp lamp, a metal halide lamp, a mercury short arc lamp, or the like may be used as long as it irradiates ultraviolet rays in the range of 350 to 450 nm.

  Furthermore, 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) can also be used. As a laser light source of the direct drawing machine, either a gas laser or a solid laser may be used as long as laser light having a maximum wavelength in the range of 350 to 410 nm is used.

The amount of exposure for image formation varies depending on the film thickness and the like, but is generally 20 to 800 mJ / cm ² , preferably 20 to 600 mJ / cm ² .

  The developing method can be a dipping method, a shower method, a spray method, a brush method or the like, and as a developer, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, Alkaline aqueous solutions such as ammonia and amines can be used.

  Furthermore, when the flame retardant curable resin composition of the present invention includes a thermosetting component, for example, by heating to a temperature of about 140 to 180 ° C. and thermosetting, the carboxyl group of the carboxyl group-containing resin, A thermosetting component reacts to form a cured coating film excellent in various properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical characteristics.

  The following examples illustrate the invention in more detail. The present invention is not limited to the following examples. In the examples, “parts” and “%” of the material usage fee are based on mass unless otherwise specified.

  The photocurable resin composition of the present invention is suitable as a permanent film for a printed wiring board, and particularly suitable as a solder resist or an interlayer insulating material.

[Examples 1 to 9 and Comparative Examples 1 to 4]
Each material was blended with the composition described in Table 1 described later, premixed with a stirrer, and then kneaded with a three-roll mill to prepare a thermosetting resin composition.

  The photosensitive carboxyl group-containing resin solution, the non-photosensitive carboxyl group-containing resin solution, and silica (slurry) were produced by the following procedure.

[Synthesis of photosensitive carboxyl group-containing resin solution A-1]
In an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device and a stirring device, 119.4 g of a novolac type cresol resin (manufactured by Showa Denko KK, Shonor (registered trademark) CRG951, OH equivalent: 119.4) Then, 1.19 g of potassium hydroxide and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was increased by heating.

Next, 63.8 g of propylene oxide was gradually dropped from the above alkylene oxide introduction apparatus, and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. Thereafter, the reaction solution was cooled to room temperature, and 1.56 g of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The nonvolatile content was 62.1% and the hydroxyl value was 182.2 g / eq. A novolak-type cresol resin propylene oxide reaction solution was obtained. This was an average of 1.08 moles of alkylene oxide added per equivalent of phenolic hydroxyl group.

  293.0 g of the resulting novolac-type cresol resin alkylene oxide reaction solution, 43.2 g of acrylic acid, 11.53 g of methanesulfonic acid, 0.18 g of methylhydroquinone and 252.9 g of toluene were mixed with a stirrer, thermometer and air blowing tube. The reaction vessel was charged with air at a rate of 10 ml / min and reacted at 110 ° C. for 12 hours while stirring. As the water produced by the reaction, 12.6 g of water was distilled as an azeotrope with toluene.

  Thereafter, the resulting reaction solution was cooled to room temperature, neutralized with 35.35 g of a 15% aqueous sodium hydroxide solution, and then washed with water. Then, the toluene was distilled off while substituting 118.1 g of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolak acrylate resin solution. Further, 332.5 g of the obtained novolak acrylate resin solution and 1.22 g of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer, and an air blowing tube, and air was blown at a rate of 10 ml / min for stirring. Then, 60.8 g of tetrahydrophthalic anhydride was gradually added and reacted at 95 to 101 ° C. for 6 hours.

  Thus, a resin solution of a carboxyl group-containing photosensitive resin having a solid acid value of 88 mgKOH / g and a nonvolatile content of 71% was obtained. Hereinafter, this is referred to as varnish A-1.

[Synthesis of photosensitive carboxyl group-containing resin solution A-2]
Orthoethylene glycol novolak type epoxy resin (DIC Corporation, EPICLON (registered trademark) N-695, softening point 95 ° C., epoxy equivalent 214, average functional group number 7.6) 1070 g (number of glycidyl groups) Total number of aromatic rings): 5.0 mol), 360 g of acrylic acid (5.0 mol), and 1.5 g of hydroquinone were charged, and the mixture was heated and stirred at 100 ° C. to uniformly dissolve.

  Next, 4.3 g of triphenylphosphine was charged, heated to 110 ° C. and reacted for 2 hours, then heated to 120 ° C. and reacted for further 12 hours. To the obtained reaction liquid, 415 g of aromatic hydrocarbon (Sorvesso 150) and 456.0 g (3.0 mol) of tetrahydrophthalic anhydride were charged, reacted at 110 ° C. for 4 hours, and cooled.

  Thus, a resin solution having a solid content acid value of 89 mgKOH / g and a solid content of 65% was obtained. Hereinafter, this is referred to as varnish A-2.

[Synthesis of carboxyl group-containing resin solution B-1 having no photosensitivity]
In an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device and a stirring device, 119.4 g of a novolac type cresol resin (manufactured by Showa Denko KK, Shonor (registered trademark) CRG951, OH equivalent: 119.4) Then, 1.19 g of potassium hydroxide and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was increased by heating.

Next, 63.8 g of propylene oxide was gradually added dropwise and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. Thereafter, the reaction solution was cooled to room temperature, and 1.56 g of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The nonvolatile content was 62.1% and the hydroxyl value was 182.2 g / eq. A novolak-type cresol resin propylene oxide reaction solution was obtained. This was an average of 1.08 moles of alkylene oxide added per equivalent of phenolic hydroxyl group.

  Further, 293 g of the above product and 1.22 g of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was blown at a rate of 10 ml / min. While stirring, tetrahydrophthalic anhydride ( 152 g of molecular weight 152) was gradually added and reacted at 95 to 101 ° C. for 6 hours.

  Thus, a resin solution of a carboxyl group-containing resin having a solid acid value of 100 mgKOH (56) / g and a nonvolatile content of 75% was obtained. Hereinafter, this is referred to as Varnish B-1.

[Synthesis of carboxyl group-containing resin solution B-2 having no photosensitivity]
A polycarbonate diol derived from 1,5-pentanediol and 1,6-hexanediol as a compound having two or more alcoholic hydroxyl groups in a reaction vessel equipped with a stirrer, a thermometer, and a condenser (Asahi Kasei Chemicals Corporation) ), TJ5650J, number average molecular weight 800) 3600 g (4.5 mol), dimethylolbutanoic acid 814 g (5.5 mol), and n-butanol 118 g (1. 6 mol) was charged. Next, 2009 g (10.8 mol) of trimethylhexamethylene diisocyanate was added as an isocyanate compound having no aromatic ring, and the mixture was heated to 60 ° C. with stirring and stopped, and when the temperature in the reaction vessel began to decrease. The mixture was heated again and stirred at 80 ° C., and the reaction was terminated after confirming that the absorption spectrum (2280 cm −1) of the isocyanate group had disappeared in the infrared absorption spectrum. Subsequently, carbitol acetate was added so that a solid content might be 60 wt%, and the viscous liquid carboxyl group-containing resin containing a diluent was obtained. The acid value of the solid content of the obtained carboxyl group-containing polyurethane was 49.8 mgKOH / g. Hereinafter, this is referred to as Varnish B-2.

[Preparation of spherical silica slurry]
500 g of true spherical silica, 495 g of diethylene glycol monoethyl ether acetate (carbitol acetate) as a solvent, and 5 g of vinyl silane coupling agent as a silane coupling agent were mixed and stirred, and dispersion treatment was performed using 0.5 μm zirconia beads in a bead mill. . This was repeated three times and filtered through a 3 μm filter to prepare silica slurries with average particle sizes of 150 nm, 200 nm, 300 nm, 450 nm, and 770 nm.

＊1： ２，４，６−トリメチルベンゾイル−ジフェニル−フォスフィンオキサイド（ルシリンＴＰＯ： ＢＡＳＦジャパン社製）
＊2： エタノン，１−［９−エチル−６−（２−メチルベンゾイル）−９Ｈ−カルバゾール−３−イル］−，１，１−（Ｏ−アセチルオキシム）（イルガキュア ＯＸＥ ０２：ＢＡＳＦジャパン社製）
＊3： (株)アドマテックス製球状シリカスラリー
＊4： Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｂｌｕｅ １５：３
＊5： Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｙｅｌｌｏｗ１４７
＊6： 2-メルカプトベンゾチアゾール
＊7： ジエチレングリコールモノエチルエーテールアセテート
＊8： ナフタレン型エポキシ樹脂（ＥＳＮ―３５５：新日鐵化学製）
＊9： ビスフェノール型エポキシ樹脂（ＹＳＬＶ−８０ＸＹ：東都化成社製）
＊10： ジペンタエリスリトールペンタアクリレート
＊11： トリシクロデカンジメタノールジアクリレート
*12： FUSELEX WX（龍森製）

* 1: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Lucirin TPO: manufactured by BASF Japan)
* 2: Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1,1- (O-acetyloxime) (Irgacure OXE 02: manufactured by BASF Japan Ltd. )
* 3: Spherical silica slurry manufactured by Admatechs Co., Ltd. * 4: C.I. I. Pigment Blue 15: 3
* 5: C.I. I. Pigment Yellow147
* 6: 2-mercaptobenzothiazole * 7: Diethylene glycol monoethyl ether acetate * 8: Naphthalene type epoxy resin (ESN-355: manufactured by Nippon Steel Chemical Co., Ltd.)
* 9: Bisphenol type epoxy resin (YSLV-80XY: manufactured by Tohto Kasei Co., Ltd.)
* 10: Dipentaerythritol pentaacrylate * 11: Tricyclodecane dimethanol diacrylate
* 12: FUSELEX WX (manufactured by Tatsumori)

  Using the photocurable resin compositions (varnishes) produced in Examples 1 to 9 and Comparative Examples 1 to 4, evaluation samples were prepared by the following operation.

<1-1. Preparation of optimum exposure dose evaluation sample>
A circuit pattern substrate having a copper thickness of 18 μm was subjected to a surface roughening treatment using a copper surface roughening agent (MEC Etch Bond (registered trademark) CZ-8100 manufactured by MEC Co., Ltd.), then washed with water and dried. .

  And the photocurable resin composition of Example 1-9 and Comparative Example 1-4 was apply | coated to the whole board | substrate surface by the screen-printing method, and it was made to dry for 30 minutes with an 80 degreeC hot-air circulation type drying furnace. The film thickness of the dried resin composition was 20 μm. This was used as a sample for the following optimum exposure measurement evaluation.

<1-2. Optimal exposure measurement>
Using an exposure apparatus equipped with a high-pressure mercury lamp, each evaluation sample was exposed in a state where a step tablet (Kodak No. 2) was arranged between the exposure apparatus and the evaluation sample. A step tablet is a film having a density gradient. By interposing this film between a sample and an exposure apparatus, the gradient is such that the exposure amount increases in 21 steps for each sample in one exposure. Exposure is performed.

The sample for evaluation after exposure was developed using 0.2 MPa, 1 wt% aqueous sodium carbonate solution at 30 ° C. for 90 seconds. The amount of light of the exposure apparatus was adjusted so that the resin from the side of the step tablet where the film density was high (low light transmission amount) to the section corresponding to the eighth stage was uncured and removed by development. The amount of light used to cure the resin was evaluated according to the following criteria.

○: Exposure amount is less than 300 mJ / cm ² Δ: Exposure amount is 300 mJ / cm ² or more and less than 500 mJ / cm ² ×: Exposure amount is 500 mJ / cm ² or more

<2-1. Preparation of samples for evaluating thermal shock resistance>
A solution obtained by appropriately diluting the photocurable resin compositions of Example 1-9 and Comparative Example 1-4 with ml of methyl ethyl ketone, respectively, was applied to a PET carrier film (Toray Industries, FB-50: 16 μm) as an applicator. And dried at 80 ° C. for 30 minutes. The film thickness of the dried film was 20 μm.

  The obtained dry film was laminated on a circuit pattern substrate having a copper thickness of 18 μm using a vacuum laminator so that the curable resin layer was in contact with the substrate. After exposing the solder resist pattern to the base material with the above optimum exposure amount using an exposure apparatus equipped with a high-pressure mercury short arc lamp (□ extraction, ○ extraction), the PET carrier film was peeled off.

Development was performed with a 1 mass% sodium carbonate aqueous solution at 30 ° C. under a spray pressure of 0.2 MPa for 60 seconds to obtain a solder resist pattern. This base material was irradiated with ultraviolet rays under a condition of an integrated exposure amount of 1000 mJ / cm ^{2 in} a UV conveyor furnace, and then cured by heating at 160 ° C. for 60 minutes. The obtained printed wiring board was used as the following sample for evaluating thermal shock resistance.

<2-2. Thermal shock resistance evaluation>
Using a thermal shock tester (manufactured by ETAC Co., Ltd.), the thermal shock resistance evaluation sample was held at −55 ° C. for 30 minutes, then heated to 125 ° C. and maintained for 30 minutes. With this as one cycle, a resistance test of 500 cycles was performed.

After the test, the cured product pattern after the treatment was visually observed to evaluate the occurrence of cracks. The judgment criteria are as follows.
◯: Crack occurrence rate of less than 20% Δ: Crack occurrence rate of 30% to less than 50% ×: Crack occurrence rate of 50% or more

<3-1. Preparation of sample for resolution evaluation>
A sample for evaluation of resolution was prepared in the same manner as the preparation of the sample for evaluation of thermal shock resistance. However, for this test, pattern exposure was performed so as to provide an opening of 80 μm in the dry film instead of □ and ◯. This was used as a sample for the following resolution evaluation.

<3-2. Evaluation of resolution>
An opening having an opening diameter of 80 μm was observed with an SEM (scanning electron microscope) and evaluated according to the following criteria.
○: Good shape in which Cu at the bottom of the opening is confirmed ×: Poor shape of opening in which Cu at the bottom of the opening is not confirmed

<4-1. Preparation of sample for warpage evaluation>
The photocurable resin compositions of Example 1-9 and Comparative Example 1-4 were applied to a 35 μm copper foil. This was used as the following warpage evaluation sample.

<4-2. Warpage evaluation>
The sample for warpage evaluation was cured under the same conditions as in 2-1, to form a cured product. The cured product was cut into a 50 mm × 50 mm square with a copper foil, measured for four corners, and averaged, and evaluated according to the following criteria.
○: Warpage is less than 10 mm.
Δ: Warpage is 10 mm or more and less than 15 mm.
X: The warp is 15 mm or more.

<5-1. Preparation of HAST resistance evaluation sample>
A sample for HAST resistance evaluation was prepared in the same manner as the preparation of the sample for evaluation of thermal shock resistance. However, for this test, the dry film was replaced with an electrolytic gold-plated copper 18 μm thick circuit pattern substrate on a BT substrate on which comb-shaped electrodes (line / space = 15 microns / 15 microns) were formed. I gave it. This was used as the following HAST resistance evaluation sample.

<5-2. HAST resistance evaluation>
This HAST resistance evaluation sample was placed in a high-temperature and high-humidity tank under an atmosphere of 130 ° C. and 85% humidity, charged with a voltage of 5.5 V, and subjected to an in-chamber HAST test for 168 hours.

  The insulation resistance value in the tank at the time of 168 hours passed was measured, and HAST tolerance was evaluated. The judgment criteria are as follows.

○: More than 10 ⁸ Ω Δ: 10 ⁶ to 10 ⁸ Ω
×: Less than 10 ⁶ Ω or short circuit occurred

  The silica compounding amount (residue amount) was measured using the resin compositions of Examples 1 to 15 and Comparative Examples 1 to 4 at a temperature condition of 800 to 1000 ° C. using TG / DTA6200 manufactured by Hitachi High-Tech Science Co., Ltd.

The test results are shown in Table 2 below.

  Considering the results of the above tests, the photocurable resin composition of the present invention shows satisfactory results in all of the exposure amount, resolution, warpage, thermal shock resistance and HAST resistance.

  On the other hand, in the comparative examples, none of the silica particles having a particle size of 300 nm or less is used, or the photosensitive carboxyl group-containing resin and the non-photosensitive carboxyl group-containing resin are not used, and the obtained curing In the product, the well-balanced characteristic improvement as in the present invention was not performed. The resolution of Comparative Example 4 was not sufficiently evaluated because undercut was confirmed and a good cured product was not obtained.

  The present invention is not limited to the configurations and examples of the above-described embodiment, and various modifications are possible within the scope of the gist of the invention.

The above purpose
(A-1) a carboxyl group-containing resin having no photosensitive group ,
(B) a photopolymerization initiator, and (C) a spherical silica filler having an average particle size of 300 nm or less,
And (C) the amount of the spherical silica filler having an average particle diameter of 300 nm or less is 60% by mass or more based on the total amount of the photocurable resin composition. It has been found to be achieved with a photocurable resin composition that is developable with the aqueous alkaline solution characterized.

The photocurable resin composition of the present invention, et al in (A-2) is preferably contains a carboxyl group-containing resin having a photosensitive group.

[Examples 1 to 9 and Comparative Examples 1 to 4]
At compositions shown in Table 1 below, compounding the materials respectively, were premixed using a stirrer and then kneaded with a three-roll mill, and the photo-curable resin composition was prepared.

[Synthesis of photosensitive carboxyl group-containing resin solution A-2 (1) ]
In an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device and a stirring device, 119.4 g of a novolac type cresol resin (manufactured by Showa Denko KK, Shonor (registered trademark) CRG951, OH equivalent: 119.4) Then, 1.19 g of potassium hydroxide and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was increased by heating.

Thus, a resin solution of a carboxyl group-containing photosensitive resin having a solid acid value of 88 mgKOH / g and a nonvolatile content of 71% was obtained. Hereinafter, this is referred to as varnish A-2 (1) .

[Synthesis of photosensitive carboxyl group-containing resin solution A-2 (2) ]
Orthoethylene glycol novolak type epoxy resin (DIC Corporation, EPICLON (registered trademark) N-695, softening point 95 ° C., epoxy equivalent 214, average functional group number 7.6) 1070 g (number of glycidyl groups) Total number of aromatic rings): 5.0 mol), 360 g of acrylic acid (5.0 mol), and 1.5 g of hydroquinone were charged, and the mixture was heated and stirred at 100 ° C. to uniformly dissolve.

Thus, a resin solution having a solid content acid value of 89 mgKOH / g and a solid content of 65% was obtained. Hereinafter, this is referred to as varnish A-2 (2) .

[Synthesis of carboxyl group-containing resin solution A-1 (1) having no photosensitivity]
In an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device and a stirring device, 119.4 g of a novolac type cresol resin (manufactured by Showa Denko KK, Shonor (registered trademark) CRG951, OH equivalent: 119.4) Then, 1.19 g of potassium hydroxide and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was increased by heating.

Thus, a resin solution of a carboxyl group-containing resin having a solid acid value of 100 mgKOH (56) / g and a nonvolatile content of 75% was obtained. Hereinafter, this is referred to as varnish A-1 (1) .

[Synthesis of carboxyl group-containing resin solution A-1 (2) having no photosensitivity]
A polycarbonate diol derived from 1,5-pentanediol and 1,6-hexanediol as a compound having two or more alcoholic hydroxyl groups in a reaction vessel equipped with a stirrer, a thermometer and a condenser (Asahi Kasei Chemicals Corporation) ), TJ5650J, number average molecular weight 800) 3600 g (4.5 mol), dimethylolbutanoic acid 814 g (5.5 mol), and n-butanol 118 g (1. 6 mol) was charged. Next, 2009 g (10.8 mol) of trimethylhexamethylene diisocyanate was added as an isocyanate compound having no aromatic ring, and the mixture was heated to 60 ° C. with stirring and stopped, and when the temperature in the reaction vessel began to decrease. The mixture was heated again and stirred at 80 ° C., and the reaction was terminated after confirming that the absorption spectrum (2280 cm −1) of the isocyanate group had disappeared in the infrared absorption spectrum. Subsequently, carbitol acetate was added so that a solid content might be 60 wt%, and the viscous liquid carboxyl group-containing resin containing a diluent was obtained. The acid value of the solid content of the obtained carboxyl group-containing polyurethane was 49.8 mgKOH / g. Hereinafter, this is referred to as varnish A-1 (2) .

Claims (10)

(A) an alkali-soluble resin,
(B) a photopolymerization initiator, and (C) a spherical silica filler having an average particle size of 300 nm or less,
A photocurable resin composition comprising:
(C) The amount of spherical silica filler having an average particle size of 300 nm or less is 60% by mass or more based on the total amount of the photocurable resin composition, and is developable with an aqueous alkali solution. Resin composition.   The photocurable resin composition developable with an alkaline aqueous solution according to claim 1, wherein the (A) alkali-soluble resin is (A-1) a carboxyl group-containing resin having no photosensitive group. .   The photocurable resin composition developable with an aqueous alkali solution according to claim 2, further comprising (A-2) a carboxyl group-containing resin having a photosensitive group as the (A) alkali-soluble resin.   Furthermore, (D) epoxy resin is contained, The photocurable resin composition of any one of Claims 1-3 characterized by the above-mentioned.   The photocurable resin composition according to any one of claims 1 to 4, wherein the (D) epoxy resin is (D-1) an epoxy resin having a naphthalene structure.   (A-1) The carboxyl group-containing resin not having photosensitivity is a carboxyl group-containing resin obtained by reacting a polybasic acid anhydride with a polyalcohol resin obtained by modifying a polyphenol compound with an alkylene oxide. The photocurable resin composition which can be developed with the aqueous alkali solution of any one of Claims 1-5.   The carboxyl group-containing resin (A-2) having photosensitivity is obtained by reacting (meth) acrylic acid with a polyalcohol resin obtained by modifying a polyphenol compound with an alkyleneoside and further reacting with polybasic acid anhydride. It is group-containing resin, The photocurable resin composition which can be developed with the aqueous alkali solution of any one of Claims 1-6 characterized by the above-mentioned.   The photocurable dry film obtained by apply | coating and drying the photocurable resin composition of any one of Claims 1-7 on a carrier film.   A photocurable resin composition according to any one of claims 1 to 7, or a photocurable dry film obtained by applying and drying the photocurable resin composition on a film, and obtained by photocuring. Cured product.   A photocurable resin composition according to any one of claims 1 to 7, or a photocurable dry film obtained by applying and drying the photocurable resin composition on a film, is applied onto a substrate. A printed wiring board having a cured coating obtained by thermally curing after the coating of the photocurable resin composition is provided and the coating is photocured by irradiation with active energy rays.