TWI878519B - Curable resin composition, dry film, cured product and printed wiring board - Google Patents

Abstract

A curable resin composition comprising (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a thermosetting resin, and (D) a coloring agent, wherein the curable resin composition is formed on a copper surface subjected to a CZ treatment, wherein the transmittance of a dry coating film (film thickness 20 μm) of the curable resin composition formed on a glass substrate having a thickness of 2 mm is 30 to 50% at a wavelength of 430 nm and 28 to 45% at a wavelength of 530 nm.

Description

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

The present invention relates to a curable resin composition, a dry film, a cured product and a printed wiring board.

For example, in the manufacture of printed wiring boards, a curable resin composition is generally used to form a permanent film such as a solder resist, and dry film type compositions and liquid compositions have been developed as such curable resin compositions. Among these, alkaline developing type curable resin compositions using a dilute alkaline aqueous solution as a developer are the mainstream due to environmental concerns, and several composition systems have been proposed in the past (e.g., Patent Document 1).

In recent years, due to the rapid progress of semiconductor components, electronic devices have tended to be thinner, shorter, more powerful, and more multifunctional. Following this trend, the miniaturization and multi-sales of semiconductor packages have become practical. Specifically, IC packages such as BGA (ball grid array) and CSP (chip scale package) are used instead of IC packages such as QFP (quad flat pack package) and SOP (small outline package). In addition, in recent years, FC-BGA (flipchip ball grid array) has also become practical as a further high-density IC package. There is a demand for further thinning of permanent films such as solder resists formed on printed wiring boards (also called package substrates) used for such IC packaging. In addition, solder resists are sometimes required to be black from the perspective of concealment and design. Therefore, regarding the curable resin composition used for solder resists, there are those containing carbon black that displays black as a colorant, or those that display black by combining pigments containing multiple colors other than black. [Prior art literature] [Patent literature]

Patent document 1: Japanese Patent Application No. 61-243869 (patent application scope)

[Problems to be solved by the invention]

Most current solder resists are photocured to form an image, and then heat-cured. The heat-curing process may cause the copper circuit to discolor due to oxidation. When marking ink is applied to the substrate, the solder resist is cured and then the marking is printed and heat-cured, which may accelerate the discoloration of the copper circuit. Furthermore, in order to correct the substrate warping caused by the heat curing of the solder resist, pressure and heat are applied, which may also cause the circuit to discolor. This discoloration cannot be concealed by the previous black curing resin composition, and the appearance of the substrate is deteriorated. Furthermore, even the conventional curable resin composition containing a blue colorant in a manner that displays black by combining with the copper color of the copper circuit has insufficient concealment, and there is still room for improvement in the concealment of the copper circuit that has been subjected to the CZ treatment for roughening the copper surface to improve adhesion. In addition, the solder resist must avoid the reduction of resolution due to the formulation of the colorant as much as possible, and requires both concealment and resolution at a high level. In the past, it was necessary to change the components other than the color tone, and in the case of attaching importance to resolution, it was necessary to reduce the amount of black pigment added to ensure concealment. In this case, depending on the curing conditions, the color tone will change due to the oxidation of the copper circuit.

Therefore, the purpose of the present invention is to provide a hardening resin composition that can be developed by alkali, which has excellent hiding power, little color change after heating, and excellent resolution, and a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and a printed wiring board having the cured product. [Means for solving the problem]

The inventors of the present invention have actively studied the above results and found that under specific test conditions, a hardening resin composition with a transmittance within a specific range can form a coating on copper treated with CZ with excellent concealment, less color change after heating, and excellent resolution, thereby completing the present invention.

That is, the characteristic of the curable resin composition of the present invention is that it contains (A) alkali-soluble resin, (B) photopolymerization initiator, (C) thermosetting resin and (D) coloring agent, and is a curable resin composition formed on copper with a CZ-treated surface, wherein the transmittance of the dry coating film (film thickness 20μm) of the aforementioned curable resin composition formed on a glass substrate with a thickness of 2mm is 30-50% at a wavelength of 430nm and 28-45% at a wavelength of 530nm.

The curable resin composition of the present invention preferably has a transmittance of the dried coating of less than 12% at a wavelength of 720 nm.

The curable resin composition of the present invention preferably has a transmittance of the dried coating of 5% or more at a wavelength of 365 nm.

The dry film of the present invention is characterized by having a resin layer obtained from the aforementioned hardening resin composition.

The characteristic of the hardened material of the present invention is that it is obtained by hardening the aforementioned hardening resin composition or the resin layer of the aforementioned dry film.

The printed wiring of the present invention is characterized by having the aforementioned hardened material. [Effect of the invention]

According to the present invention, there can be provided a hardening resin composition capable of alkali developability, in which a coating formed on copper after CZ treatment has excellent hiding power, little color change after heating and excellent resolution, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and a printed wiring board having the cured product.

The characteristic of the curable resin composition of the present invention is that it contains (A) alkali-soluble resin, (B) photopolymerization initiator, (C) thermosetting resin and (D) coloring agent, and is a curable resin composition formed on copper with a CZ-treated surface. The transmittance of the dry coating film (film thickness 20μm) of the aforementioned curable resin composition formed on a glass substrate with a thickness of 2mm is 30-50% at a wavelength of 430nm and 28-45% at a wavelength of 530nm. In one example, the red colorant, yellow colorant, blue colorant and black colorant in the curable resin composition are adjusted so that the transmittance of the coating film tested on a 2 mm thick glass substrate is 30-50% at a wavelength of 430 nm and 28-45% at a wavelength of 530 nm. The hardening resin composition with this transmittance is not the conventional black hardening resin composition, nor is it the conventional blue hardening resin composition, but is a novel hardening resin composition. It is difficult to specify the coloring agent in a specific mixing ratio, but the transmittance of the dry coating film (film thickness 20μm) of the aforementioned hardening resin composition formed on a glass substrate with a thickness of 2mm is 30-50% at a wavelength of 430nm and 28-45% at a wavelength of 530nm, which has both the concealment and resolution expected by the present invention. Therefore, the hardening resin composition of the present invention is specified by the transmittance falling within a specific range under specific test conditions. The transmittance is measured by using an applicator to form a dry coating on a 2mm thick glass substrate in a manner that the curable resin composition becomes 20μm thick after drying at 80℃ for 30 minutes, or by pressing a 20μm thick dry film layer on a 2mm thick glass substrate and peeling off the carrier film. It is measured using a UV-Vis-IR spectrophotometer V-670 (manufactured by JASCO Corporation). The transmittance of the preferably dry coating is less than 12% at a wavelength of 720nm, thereby greatly suppressing the color change after heat treatment. The transmittance of the preferably dry coating is more than 5% at a wavelength of 365nm, thereby improving the resolution.

The following is a description of the components of the curable resin composition of the present invention. In addition, in this specification, the term "(meth)acrylate" is a general term for acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

[(A) Alkali-soluble resin] Examples of (A) alkali-soluble resins include compounds having two or more phenolic hydroxyl groups, carboxyl-containing resins, compounds having phenolic hydroxyl groups and carboxyl groups, and compounds having two or more thiol groups. Among them, if the alkali-soluble resin is a carboxyl-containing resin or a phenolic resin, it is preferred because the adhesion to the substrate is improved. In particular, the alkali-soluble resin is more preferably a carboxyl-containing resin because of its excellent developing properties. The carboxyl-containing resin is preferably a carboxyl-containing photosensitive resin having an ethylenically unsaturated double bond, but may also be a carboxyl-containing resin without an ethylenically unsaturated double bond.

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

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

(2) A carboxyl-containing urethane resin obtained by subjecting a diisocyanate such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate, an aromatic diisocyanate, a carboxyl-containing diol compound such as dihydroxymethylpropionic acid and dihydroxymethylbutyric acid, and a diol compound such as a polycarbonate polyol, a polyether polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, a bisphenol A-based epoxyalkyl adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group to a polyaddition reaction.

(3) Urethane resins containing carboxyl groups at the end obtained by reacting the terminal of a urethane resin obtained by the polyaddition reaction of a diisocyanate such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, alicyclic diisocyanate, or an aromatic diisocyanate with a diol compound such as a polycarbonate polyol, a polyether polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, a bisphenol A-based epoxide adduct diol, or a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group with an acid anhydride.

(4) A carboxyl-containing urethane resin obtained by subjecting a diisocyanate to a polyaddition reaction with a (meth)acrylate of a bifunctional epoxy resin such as bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, dimethylol epoxy resin, biphenol epoxy resin or a partially anhydride-modified product thereof, a carboxyl-containing diol compound and a diol compound.

(5) In the synthesis of the resin of (2) or (4) above, a compound having one hydroxyl group and one or more (meth)acryl groups in the molecule, such as (meth)acrylate hydroxyalkyl ester, is added to prepare a carboxyl-containing urethane resin which is terminally (meth)acrylated.

(6) In the resin synthesis of (2) or (4) above, a terminally (meth)acrylated carboxyl-containing urethane resin having 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, is added.

(7) A polyfunctional epoxy resin is reacted with (meth) acrylic acid to obtain a carboxyl-containing resin having a dibasic acid anhydride such as isophthalic anhydride, tetrahydroisophthalic anhydride, or hexahydrophthalic anhydride, by adding a hydroxyl group to the side chain.

(8) The hydroxyl group of a bifunctional epoxy resin is further epoxidized with epichlorohydrin to produce a polyfunctional epoxy resin which reacts with (meth)acrylic acid, and a carboxyl-containing resin is added to the produced hydroxyl group to produce a dibasic acid anhydride.

(9) A carboxyl-containing polyester resin is prepared by reacting a polyfunctional cyclohexane resin with a dicarboxylic acid and adding a dibasic acid anhydride to the generated primary hydroxyl group.

(10) A carboxyl-containing resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one part with an alkylene oxide such as ethylene oxide or propylene oxide, and then reacting the resulting reaction product with a monocarboxylic acid containing an unsaturated group and reacting the resulting reaction product with a polyacid anhydride.

(11) A carboxyl-containing resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one part with a cyclic carbonate compound such as ethyl carbonate or propylene carbonate, the resulting reaction product with a monocarboxylic acid containing an unsaturated group, and reacting the resulting reaction product with a polyacid anhydride.

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

(13) A carboxyl-containing resin obtained by further adding a compound having one epoxy group and one or more (meth)acryloyl groups in the molecule such as (meth)acrylate glycidyl, (meth)acrylate α-methylglycidyl, etc. to the carboxyl-containing resin described in (1) to (12) above.

Among the above carboxyl-containing resins, the carboxyl-containing resins described in (1), (7), (8), (10) to (13) are preferred.

Examples of the compound having a phenolic hydroxyl group include compounds having a biphenyl skeleton or a phenylene skeleton or both skeletons, or phenol resins having various skeletons synthesized using phenol, o-cresol, p-cresol, m-cresol, 2,3-dimethylphenol, 2,4-dimethylphenol, 2,5-dimethylphenol, 2,6-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, catechol, resorcinol, hydroquinone, methylhydroquinone, 2,6-dimethylhydroquinone, trimethylhydroquinone, pyrogallol, phloroglucinol, and the like.

Examples of the compound having a phenolic hydroxyl group include well-known and commonly used phenolic resins such as phenol novolac resins, alkylphenol novolac resins, bisphenol A novolac resins, dicyclopentadiene-type phenolic resins, Xylok-type phenolic resins, terpene-modified phenolic resins, polyvinylphenols, bisphenol F, bisphenol S-type phenolic resins, poly-p-hydroxystyrene, condensates of naphthol and aldehydes, and condensates of dihydroxynaphthalene and aldehydes.

Commercially available products of phenolic resins include, for example, HF1H60 (manufactured by Meiwa Chemicals Co., Ltd.), Phenolite TD-2090, Phenolite TD-2131 (manufactured by DIC Corporation), Besmol CZ-256-A (manufactured by DIC Corporation), Shonol BRG-555, Shonol BRG-556 (manufactured by AICA Corporation), and polyvinyl phenol CST70, CST90, S-1P, S-2P (manufactured by Maruzen Oil Company).

(A) The acid value of the alkali-soluble resin is preferably in the range of 40 to 200 mgKOH/g, and more preferably in the range of 45 to 120 mgKOH/g. When the acid value of the alkali-soluble resin is 40 mgKOH/g or more, alkali development becomes easier. On the other hand, when the acid value is 200 mgKOH/g or less, normal resist patterns can be easily drawn, which is preferred.

(A) The weight average molecular weight of the alkali-soluble resin varies depending on the resin skeleton, but is preferably in the range of 1,500 to 150,000, and more preferably in the range of 1,500 to 100,000. If the weight average molecular weight is 1,500 or more, the non-stick performance is good, the moisture resistance of the coating after exposure is good, the film deterioration during development can be suppressed, and the reduction in resolution can be suppressed. On the other hand, if the weight average molecular weight is 150,000 or less, the developing property is good and the storage stability is also excellent.

(A) The alkali-soluble resin may be used alone or in combination of two or more.

[(B) Photopolymerization initiator] In the curable resin composition of the present invention, as the (B) photopolymerization initiator, any photopolymerization initiator known as a photopolymerization initiator or a photoradical generator can be used. Examples of the photopolymerization initiator (B) include bis-(2,6-dichlorobenzyl)phenylphosphine oxide, bis-(2,6-dichlorobenzyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzyl)phenylphosphine oxide (Omnirad manufactured by IGM Resins Co., Ltd.) 819) and the like; 2,6-dimethoxybenzyldiphenylphosphine oxide, 2,6-dichlorobenzyldiphenylphosphine oxide, methyl 2,4,6-trimethylbenzylphenylphosphine oxide, 2-methylbenzyldiphenylphosphine oxide, isopropyl tert-butylphenylphosphine oxide, 2,4,6-trimethylbenzyldiphenylphosphine oxide (Omnirad TPO manufactured by IGM Resins Co., Ltd.) H) and the like; hydroxyacetophenones such as 1-hydroxy-cyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methyl-propane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, etc.; benzoin, biphenyl acyl, benzoin methyl ether, benzoin ethyl ether, benzoin Benzoins such as n-propyl ether, isopropyl ether, and n-butyl ether; benzoin alkyl ethers; benzophenones such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bis(diethylamino)benzophenone; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-( Acetophenones such as 2-(4-methylthio)phenyl]-2-pyroline-1-propanone, 2-benzyl-2-dimethylamino-1-(4-pyrolinephenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-pyroline)phenyl]-1-butanone, N,N-dimethylaminoacetophenone, etc.; thiothione, 2-ethylthiothione, 2-isopropylthiothione, 2,4-dimethylthiothione, 2,4-diethylthiothione, 2-chlorothiothione , 2,4-diisopropylthioxanthene, etc.; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone, etc.; acetals such as acetophenone dimethyl acetal, benzyl dimethyl acetal, etc.; benzoic acid esters such as ethyl 4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, ethyl p-dimethylbenzoate, etc.; 1,2-octanedione, 1-[4-(phenylthio)-, Oxime esters such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium and bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyridin-yl)ethyl)phenyl]titanium; phenyl disulfide, 2-nitrofluorene, butyroin, anisole ether, azobisisobutyronitrile, tetramethylthiuram disulfide, etc. The photopolymerization initiator may be used alone or in combination of two or more. Among them, oxime esters (hereinafter also referred to as "oxime ester photopolymerization initiators") are preferred, and acetone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-, 1-(O-acetyl oxime) is more preferred. The amount of the (B) photopolymerization initiator is, for example, 0.01 to 30 parts by mass relative to 100 parts by mass of the alkali-soluble resin (A). The amount of the oxime ester photopolymerization initiator is preferably 8% by mass or more, and more preferably 12% by mass or more, per the total amount of the photopolymerization initiator, in terms of solid content. When the amount is 8% by mass or more, high sensitivity can be easily achieved. The oxime ester-based photopolymerization initiator may be used alone or in combination of two or more.

As the oxime ester photopolymerization initiator, any known oxime ester photopolymerization initiator may be used. Examples of commercially available products include Irgacure OXE01 (1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyl oxime)]) and Irgacure OXE02 (ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-, 1-(O-acetyl oxime)) manufactured by BASF Japan, N-1919 and NCI-831 manufactured by ADEKA, and TR-PBG-304 manufactured by Changzhou Qiangli Electronic New Materials Co., Ltd.

In addition, an initiator having two oxime ester groups in the molecule can also be preferably used, and a specific example is an oxime ester compound having a carbazole structure represented by the following general formula. (wherein, X represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group, a phenyl group (substituted by an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms, or a dialkylamino group), a naphthyl group (substituted by an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms, or a dialkylamino group), Y and Z each independently represent a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a halogen group, a phenyl group, a phenyl group (substituted by an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms, or a dialkylamino group) substituted with an alkyl radical having 1 to 8 carbon atoms, an alkylamino radical or a dialkylamino radical having an alkyl radical having 1 to 8 carbon atoms), naphthyl (substituted with an alkyl radical having 1 to 17 carbon atoms, an alkoxy radical having 1 to 8 carbon atoms, an amino radical, an alkylamino radical or a dialkylamino radical having an alkyl radical having 1 to 8 carbon atoms), anthracenyl, pyridyl, benzofuranyl, benzothienyl, Ar represents a single bond, or an alkylene radical having 1 to 10 carbon atoms, vinylene radical, phenylene radical, biphenylene radical, pyridylene radical, naphthylene radical, thienyl, anthracene radical, thienylene radical, furanyl, 2,5-pyrrolediyl, 4,4'-diphenylethylenediyl, 4,2'-phenylenediyl, and n represents an integer from 0 to 1).

In particular, in the above general formula, preferably X and Y are methyl or ethyl, respectively, Z is methyl or phenyl, n is 0, Ar is a single bond, or phenylene, naphthylene, thienyl or thienylene.

Furthermore, as preferred carbazole oxime ester compounds, compounds represented by the following general formula can also be exemplified. (In the formula, ^R1 represents an alkyl group having 1 to 4 carbon atoms or a phenyl group which may be substituted by a nitro group, a halogen atom or an alkyl group having 1 to 4 carbon atoms, ^R2 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a phenyl group which may be substituted by an alkyl group or an alkoxy group having 1 to 4 carbon atoms, ^R3 represents a benzyl group which may be linked via an oxygen atom or a sulfur atom and may be substituted by an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 4 carbon atoms which may be substituted by a phenyl group, ^R4 represents a nitro group or a cyano group represented by XC(=O), and X represents an aryl group which may be substituted by an alkyl group having 1 to 4 carbon atoms, a thienyl group, a morpholinyl group, a thiophenyl group or a structure represented by the following formula)

In addition, examples include carbazole oxime ester compounds described in Japanese Patent Application Publication Nos. 2004-359639, 2005-097141, 2005-220097, 2006-160634, 2008-094770, 2008-509967, 2009-040762, and 2011-80036.

[(C) Thermosetting resin] The curable resin composition of the present invention can be expected to have improved heat resistance by containing a thermosetting resin. The thermosetting resin can be used alone or in combination of two or more. Any known thermosetting resin can be used. For example, known thermosetting components such as melamine resin, benzoguanamine resin, melamine derivative, benzoguanamine derivative, etc., amino resin, isocyanate compound, blocked isocyanate compound, cyclocarbonate compound, epoxy compound, oxycyclobutane compound, cyclosulfide resin, dimaleimide, carbodiimide resin, etc. can be used. Particularly preferred are thermosetting resins having a plurality of cyclic ether groups or cyclic thioether groups (hereinafter referred to as cyclic (thio)ether groups) in the molecule.

The thermosetting resin having a plurality of cyclic (thio)ether groups in the above-mentioned molecule is preferably a compound having a plurality of 3-, 4- or 5-membered cyclic (thio)ether groups in the molecule, for example, a compound having a plurality of epoxy groups in the molecule, i.e., a polyfunctional epoxy compound, a compound having a plurality of oxycyclobutyl groups in the molecule, i.e., a polyfunctional oxycyclobutane compound, a compound having a plurality of thioether groups in the molecule, i.e., an epoxide resin, etc.

Examples of the polyfunctional epoxy compound include epoxidized vegetable oil; bisphenol A type epoxy resin; hydroquinone type epoxy resin; bisphenol type epoxy resin; thioether type epoxy resin; brominated epoxy resin; novolac type epoxy resin; biphenol novolac type epoxy resin; bisphenol F-type epoxy resin; hydrogenated bisphenol A-type epoxy resin; glycidylamine-type epoxy resin; hydantoin-type epoxy resin; alicyclic epoxy resin; trihydroxyphenylmethane-type epoxy resin; dimethylphenol-type or diphenol-type epoxy resin or mixtures thereof; bisphenol S-type epoxy resin Epoxy resin; bisphenol A novolac type epoxy resin; tetrahydroxyphenylethane type epoxy resin; heterocyclic epoxy resin; diglycidyl phthalate resin; tetraglycidyl dimethylbenzene ethyl resin; naphthyl-containing epoxy resin; epoxy resin having a dicyclopentadiene skeleton; methacrylate glycidyl ester copolymerized epoxy resin; epoxy resin copolymerized with cyclohexylmaleimide and methacrylate glycidyl ester; epoxy-modified polybutadiene rubber derivative; CTBN-modified epoxy resin, etc., but not limited to the above. The epoxy compounds may be used alone or in combination of two or more. Particularly preferred among these are novolac type epoxy resins, bisphenol type epoxy resins, dimethylol type epoxy resins, biphenol type epoxy resins, biphenol novolac type epoxy resins, naphthalene type epoxy resins or mixtures thereof.

Examples of the cyclohexane compound include bis[(3-methyl-3-cyclohexanebutylmethoxy)methyl]ether, bis[(3-ethyl-3-cyclohexanebutylmethoxy)methyl]ether, 1,4-bis[(3-methyl-3-cyclohexanebutylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-3-cyclohexanebutylmethoxy)methyl]benzene, (3-methyl-3-cyclohexanebutyl)methyl acrylate, and (3-methyl-3-cyclohexanebutyl)methyl acrylate. Examples include polyfunctional cyclobutanes such as (3-ethyl-3-cyclooxobutyl)methyl ester, (3-methyl-3-cyclooxobutyl)methyl methacrylate, (3-ethyl-3-cyclooxobutyl)methyl methacrylate, or oligomers or copolymers thereof, and ethers of cyclobutanes with novolac resins, poly(p-hydroxystyrene), cardo-type bisphenols, calixarene, calix resorcinarene, or silsesquioxane resins having hydroxyl groups. Examples include copolymers of unsaturated monomers having cyclooxobutyl rings and (meth) alkyl acrylates.

Examples of compounds having multiple cyclic sulfide groups in the molecule include bisphenol A type epoxide sulfide resins. In addition, epoxide sulfide resins in which the oxygen atom of the epoxy group of a novolac type epoxy resin is replaced with a sulfur atom using the same synthesis method may also be used. The amount of the thermosetting resin having multiple cyclic (sulfide) ether groups in the molecule is preferably 0.6 to 2.5 equivalents of the cyclic (sulfide) ether group, more preferably 0.8 to 2.0 equivalents, relative to 1 equivalent of the alkali-soluble group such as the carboxyl group or phenolic hydroxyl group of the alkali-soluble resin (A).

Examples of the amino resin of melamine derivatives, benzoguanamine derivatives, etc. include hydroxymethylmelamine compounds, hydroxymethylbenzoguanamine compounds, hydroxymethylglycoluril compounds, and hydroxymethylurea compounds.

As the isocyanate compound, a polyisocyanate compound can be prepared. Examples of the polyisocyanate compound include aromatic polyisocyanates such as 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, naphthalene-1,5-diisocyanate, o-xylene diisocyanate, m-xylene diisocyanate, and 2,4-toluene dimer; tetramethylene diisocyanate, hexamethylene diisocyanate, Aliphatic polyisocyanates such as methyl diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate) and isophorone diisocyanate; alicyclic polyisocyanates such as dicycloheptane triisocyanate; and adducts, biuret forms and isocyanurate forms of the isocyanate compounds listed above.

As the blocked isocyanate compound, an addition reaction product of an isocyanate compound and an isocyanate blocking agent can be used. Examples of isocyanate compounds that can react with an isocyanate blocking agent include the above-mentioned polyisocyanate compounds. Examples of isocyanate blocking agents include phenol-based blocking agents, lactam-based blocking agents, active methylene-based blocking agents, alcohol-based blocking agents, oxime-based blocking agents, thiol-based blocking agents, amide-based blocking agents, imide-based blocking agents, amine-based blocking agents, imidazole-based blocking agents, and imine-based blocking agents.

Thermosetting resins may be used alone or in combination of two or more. The amount of the thermosetting resin to be added is preferably 20 to 60 parts by mass, more preferably 30 to 50 parts by mass, relative to 100 parts by mass of the solid content of the alkali-soluble resin (A). When the amount is 20 parts by mass or more, the heat resistance is excellent. When the amount is 60 parts by mass or less, the storage stability is improved.

[(D) Colorants] Colorants may include one or a suitable combination of two or more of red colorants, green colorants, blue colorants, yellow colorants, white colorants, black colorants, or colorants of other colors. Pigments, dyes, and pigments are all acceptable. Specifically, a colorant with a color index (C.I.; issued by The Society of Dyers and Colourists) number may be used. However, from the perspective of reducing environmental impact and impact on the human body, a halogen-free colorant is preferred.

Examples of red colorants include monoazo, disazo, azochrome, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone. Green colorants include phthalocyanine, anthraquinone, and perylene, which are similarly substituted with or without metal. Blue colorants may be any of pigments, dyes, and pigments, preferably those that do not contain halogen atoms. Blue colorants include phthalocyanine and anthraquinone. Pigments are compounds classified as pigments, and specific examples include: Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, and 60. As dyes, solvent blue 35, 63, 68, 70, 83, 87, 94, 97, 122, 136, 67, 70, etc. can be used. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used. Blue colorants can be used alone or in combination of two or more. Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, anthraquinone, etc. Examples of white colorants include rutile-type, rutile-type, etc. titanium oxides, etc. Examples of black coloring agents include titanium black, carbon black, graphite, iron oxide, anthraquinone, cobalt oxide, copper oxide, manganese, antimony oxide, nickel oxide, perylene, aniline pigments, molybdenum sulfide, bismuth sulfide, etc. In addition, for the purpose of adjusting the color tone, purple, orange, brown, etc. coloring agents may also be added. When forming a hardening resin composition that can be developed by alkali and has excellent hiding power and little color change after heating and excellent resolution of the coating formed on copper after CZ treatment, the coloring agent is preferably a combination of red coloring agent, yellow coloring agent, blue coloring agent, and black coloring agent. In this case, the amount of the colorant (D) is preferably 0.01-0.04 mass parts for black colorant, 1.10-2.45 mass parts for blue colorant, 0.01-0.08 mass parts for yellow colorant, and 0.60-2.00 mass parts for red colorant, and more preferably 0.02-0.03 mass parts for black colorant, 1.40-2.20 mass parts for blue colorant, 0.03-0.06 mass parts for yellow colorant, and 0.75-1.20 mass parts for red colorant, relative to 100 mass parts of the solid content of the alkali-soluble resin (A).

[Inorganic filler] The curable resin composition of the present invention preferably contains an inorganic filler. The inorganic filler is not particularly limited, and conventionally used inorganic fillers can be used, such as silicon oxide, crystalline silicon oxide, Newberg silica, aluminum hydroxide, glass powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, aluminum hydroxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, slag wool, aluminum silicate, calcium silicate, zinc white, etc., or a combination of two or more inorganic fillers. Silicon oxide is preferred, as it accumulates on the surface with a small area, and the stress is dispersed throughout the body, and it is not easy to become the starting point of turtle cracks. Spherical silicon oxide is more preferred.

The inorganic filler may also be surface treated. Here, the surface treatment of the inorganic filler refers to a treatment for improving the compatibility with the resin component. The surface treatment of the inorganic filler may be a surface treatment for introducing a curing reactive group into the surface of the inorganic filler, or a surface treatment for not introducing a curing reactive group. Here, the curing group is not particularly limited if it is a group that undergoes a curing reaction with a curing compound such as (A) an alkali-soluble resin or (C) a thermosetting resin, and may be a curing reactive group or a thermosetting reactive group. Examples of curable reactive groups include methacrylic acid, acrylic acid, vinyl, styrene, etc., and examples of thermosetting reactive groups include epoxy, amino, hydroxyl, carboxyl, isocyanate, imino, cyclobutyl, oxadiazole, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, oxazoline, etc. The method of introducing the curable reactive group on the surface of the inorganic filler is not particularly limited, and the method can be introduced by a conventional method, such as treating the surface of the inorganic filler with a surface treatment agent having a curable reactive group, such as a coupling agent having a curable reactive group as an organic group. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent, etc. can be used. Examples of the surface-treated inorganic filler having no curable reactive group include inorganic fillers surface-treated with silica-alumina, treated with a titanium ester coupling agent, treated with an aluminate coupling agent, or treated with an organic agent.

The inorganic filler may be used alone or in combination of two or more. The amount of the inorganic filler is preferably 80 to 450 parts by mass, more preferably 100 to 200 parts by mass, relative to 100 parts by mass of the solid content of the alkali-soluble resin (A). When the amount is 80 parts by mass or more, the heat resistance is excellent. When the amount is 450 parts by mass or less, the resolution is more excellent.

(Compounds with ethylenically unsaturated groups) The curable resin composition of the present invention may contain a compound having ethylenically unsaturated groups, which functions as a reactive diluent, unlike the alkali-soluble resin (A). As the compound having ethylenically unsaturated groups, photopolymerizable oligomers of conventionally used photocurable monomers, photopolymerizable vinyl monomers, etc. may be used.

Examples of the photopolymerizable oligomer include unsaturated polyester oligomers and (meth)acrylate oligomers. Examples of the (meth)acrylate oligomer include epoxy (meth)acrylates such as phenol novolac epoxy (meth)acrylate, cresol novolac epoxy (meth)acrylate, and bisphenol epoxy (meth)acrylate, urethane (meth)acrylate, epoxyurethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, and polybutadiene modified (meth)acrylate.

As the photopolymerizable vinyl monomer, those commonly used can be used, for example, styrene derivatives such as styrene, chlorostyrene, α-methylstyrene, etc.; vinyl esters such as vinyl acetate, vinyl butyrate, or vinyl benzoate, etc.; vinyl ethers such as vinyl isobutyl ether, vinyl n-butyl ether, vinyl tert-butyl ether, vinyl n-pentyl ether, vinyl isopentyl ether, vinyl n-octadecyl ether, vinyl cyclohexyl ether, ethylene glycol monobutyl vinyl ether, triethylene glycol monomethyl vinyl ether, etc.; acrylamide, methacrylamide, N-hydroxymethyl vinyl ether, etc. (Meth)acrylamides such as 1,2-dimethacrylamide, N-hydroxymethyl methacrylamide, N-methoxy methacrylamide, N-ethoxy methacrylamide, N-butoxy methacrylamide, etc.; allyl compounds such as triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, etc.; (meth)acrylic acids such as 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, etc. Esters; hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and pentaerythritol tri(meth)acrylate; alkoxyalkylene glycol mono(meth)acrylates such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trihydroxymethylpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate; ester, dipentaerythritol hexa(meth)acrylate and the like; polyoxyalkylene glycol poly(meth)acrylates such as diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, ethoxylated trihydroxymethylpropane triacrylate, propoxylated trihydroxymethylpropane tri(meth)acrylate and the like; poly(meth)acrylates such as hydroxypivalic acid neopentyl glycol ester di(meth)acrylate and the like; isocyanurate type poly(meth)acrylates such as tri[(meth)acryloyloxyethyl] isocyanurate and the like. These may be used alone or in combination of two or more depending on the required properties.

The compound having an ethylenically unsaturated group may be used alone or in combination of two or more. The amount of the compound having an ethylenically unsaturated group is preferably 3 to 25 parts by mass, more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the solid content of the alkali-soluble resin (A). When it is 3 parts by mass or more, it contributes to high sensitivity. When it is 25 parts by mass or less, the resolution is good.

(Thermosetting catalyst) The curable resin composition of the present invention may contain a thermosetting catalyst. Examples of such thermosetting catalysts include imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, etc.; amine compounds such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzylamine, etc.; hydrazide compounds such as dihydrazide of adipic acid and dihydrazide of sebacic acid; phosphorus compounds such as triphenylphosphine, etc. In addition, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine•isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S-triazine•isocyanuric acid adduct, and other S-triazine derivatives can also be used, preferably in combination with a thermosetting catalyst. These compounds can also function as adhesion imparting agents. And if it can be used as a thermosetting catalyst, it can also be an organic filler.

The heat curing catalyst is preferably an organic filler having an amino group, and more specifically, at least one of melamine and dicyandiamide (DICY) is preferred.

The heat-curing catalyst can be used alone or in combination of two or more. The amount of the heat-curing catalyst is preferably 0.5 to 10 parts by mass, more preferably 1 to 8 parts by mass, relative to 100 parts by mass of the solid content of the alkali-soluble resin (A). When the amount is 0.5 parts by mass or more, the heat resistance is excellent. When the amount is 10 parts by mass or less, the storage stability is improved.

(Organic solvent) The curable resin composition of the present invention may contain an organic solvent for the purpose of preparing the composition or adjusting the viscosity when coating on a substrate or a carrier film. As the organic solvent, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellulose, methyl cellulose, butyl cellulose, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl acetate, butyl lactate, cellulose acetate, butyl cellulose acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha, etc., which are known and commonly used organic solvents. These organic solvents may be used alone or in combination of two or more.

(Other optional components) Other curing components or other additives commonly used in the field of electronic materials may also be formulated into the curable resin composition of the present invention. Examples of other curing components include cyanate resins, active ester resins, maleimide compounds, and alicyclic olefin polymers. Examples of other additives include thermal polymerization inhibitors, ultraviolet absorbers, silane coupling agents, plasticizers, flame retardants, antistatic agents, antioxidants, antibacterial and antimold agents, defoaming agents, leveling agents, thickeners, adhesion enhancers, thixotropic enhancers, photoinitiators, sensitizers, thermoplastic resins, organic fillers, release agents, surface treatment agents, dispersants, dispersing aids, surface modifiers, stabilizers, and fluorescent materials.

The curable resin composition of the present invention can be used in the form of a dry film or in a liquid form. When used in a liquid form, it can be a single component or a two-component or more component.

The hardening resin composition of the present invention has a resin layer obtained by coating the hardening resin composition of the present invention on a carrier film and drying it. When forming a dry film, the hardening resin composition of the present invention is first diluted with the above-mentioned organic solvent to adjust to an appropriate viscosity, and then coated on the carrier film with a uniform thickness by a notch wheel coater, a scraper coater, a lip die coater, a rod coater, a rubber roller coater, a reverse roller coater, a conveyor roller coater, a gravure coater, a spray coater, etc. Afterwards, the applied composition is dried at a temperature of 40-130°C for 1-30 minutes to form a resin layer. There is no particular restriction on the thickness of the applied film, but the thickness of the film after drying is generally in the range of 3-150μm, preferably 5-60μm.

As the carrier film, a plastic film can be used, for example, polyester film such as polyethylene terephthalate (PET), polyimide film, polyamide imide film, polypropylene film, polystyrene film, etc. The thickness of the carrier film is not particularly limited, but is generally selected in the range of 10 to 150 μm. More preferably, it is in the range of 15 to 130 μm.

After forming a resin layer made of the curable resin composition of the present invention on the carrier film, it is preferable to further deposit a peelable cover film on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. As the peelable cover film, for example, polyethylene film, polytetrafluoroethylene film, polypropylene film, surface-treated paper, etc. can be used. As the cover film, it is sufficient as long as the adhesion force of the cover film is smaller than the adhesion force between the resin layer and the carrier film when the cover film is peeled off.

In the present invention, the curable resin composition of the present invention may be applied on the above-mentioned cover film and dried to form a resin layer, and a carrier film may be laminated on the surface thereof. That is, in the present invention, when preparing a dry film, the thin film on which the curable resin composition of the present invention is applied may be either a carrier film or a cover film.

The printed wiring board of the present invention is a hardened product obtained from the hardening resin composition of the present invention or the resin layer of the dry film. As a method for manufacturing the printed wiring board of the present invention, for example, the hardening resin composition of the present invention is adjusted to a viscosity suitable for the coating method using the above-mentioned organic solvent, and after coating on the substrate by a method such as immersion coating, flow coating, roll coating, rod coating, screen printing, curtain coating, etc., the organic solvent contained in the composition is volatilized and dried (temporarily dried) at a temperature of 60-100°C to form a non-tack resin layer. In the case of a dry film, after the resin layer is brought into contact with the substrate and bonded to the substrate by a laminating press or the like, the carrier film is peeled off to form the resin layer on the substrate.

As the above-mentioned substrate, in addition to printed wiring boards or flexible printed wiring boards in which circuits are pre-formed with copper or the like, materials such as copper-clad laminates for high-frequency circuits using paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth/non-woven epoxy, glass cloth/paper epoxy, synthetic fiber epoxy, fluororesin, polyethylene, polyphenylene ether, polyphenylene oxide, cyanate, etc. can be used, copper-clad laminates of all grades (FR-4, etc.), as well as metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer boards, etc.

After applying the curable resin composition of the present invention, the volatile drying can be performed using a hot air circulation drying furnace, an IR furnace, a heating plate, a forced oven, etc. (a method of using a heat source with a steam-based air heating method to allow the hot air in the dryer to contact by convection and a method of using a nozzle to blow the support body).

After forming a resin layer on a substrate, it is selectively exposed using active energy rays through a mask formed with a specific pattern, and the unexposed part is developed by a dilute alkaline aqueous solution (e.g., a 0.3-3 mass% sodium carbonate aqueous solution) to form a pattern of a cured product. The cured product is then irradiated with active energy rays and then heat-cured (e.g., 100-220°C), or irradiated with active energy rays after heat-curing, or only heat-cured, and finally cured (formal curing) to form a cured film with excellent properties such as adhesion and hardness. In addition, when the curable resin composition of the present invention contains a photoalkali generator, it is preferably heated before development after exposure. As a heating condition before development after exposure, it is preferably heated at 60-150°C for 1-60 minutes.

As the exposure machine used for the above-mentioned active energy ray irradiation, any device that irradiates ultraviolet rays in the range of 350~450nm equipped with a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halogen lamp, a mercury arc lamp, etc. can be used. Furthermore, a direct drawing device (for example, a laser direct imaging device that directly draws images with a laser using CAD data from a computer) can also be used. As a light source or a laser light source of a direct drawing machine, it is preferably one with a maximum wavelength in the range of 350~450nm. The exposure amount used for image formation varies depending on the film thickness, etc., but is generally in the range of 10~1000 mJ/ ^cm2 , preferably in the range of 20~800mJ/ ^cm2 .

As the above-mentioned developing method, an immersion method, a rinsing method, a spray method, a brush coating method, etc. can be used, and as a developer, an alkaline aqueous solution of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc. can be used.

The curable resin composition of the present invention can be preferably used to form a cured film on a printed wiring board, and is particularly suitable for forming a permanent film, and is further suitable for forming a solder resist, an interlayer insulating film, and a cover layer. In addition, according to the thermosetting resin composition of the present invention, a cured product with excellent appearance and surface smoothness can be obtained even in the form of a thin film. Due to its excellent sensitivity and resolution, it can be applied to forming a thin film and requiring a high degree of reliability for a printed wiring board such as a packaging substrate, especially a permanent film (especially a solder resist) for FC-BGA.

In particular, the curable resin composition of the present invention can be used to form a thin film, preferably a cured film of 3 to 40 μm, more preferably 5 to 30 μm. [Example]

The following examples and comparative examples are provided to specifically illustrate the present invention, but the present invention is not limited to the following examples. In addition, the following "parts" and "%" are all based on mass unless otherwise specified.

(Synthesis of Alkaline Soluble Resin A-1) Into an autoclave equipped with a thermometer, a nitrogen and alkylene oxide inlet device, and a stirring device, 119.4 parts of cresol novolac resin (Shonol CRG951 manufactured by AICA Industries, OH equivalent: 119.4), 1.19 parts of potassium hydroxide, and 119.4 parts of toluene were introduced, and the nitrogen was replaced in the system while stirring, and the temperature was raised. Next, 63.8 parts of propylene oxide was slowly added dropwise, and the reaction was carried out at 125~132℃ and 0~4.8kg/ ^cm2 for 16 hours. Then, the mixture was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to the reaction solution to neutralize potassium hydroxide, thereby obtaining a phenolic lacquer type cresol resin propylene oxide reaction solution with a non-volatile content of 62.1% and a hydroxyl value of 182.2 mgKOH/g (307.9 g/eq.). This is a solution in which an average of 1.08 mol of phenolic hydroxyl groups are added per 1 equivalent of propylene oxide. 293.0 parts of the obtained propylene oxide reaction solution of the novolac type cresol resin, 43.2 parts of acrylic acid, 11.53 parts of methanesulfonic acid, 0.18 parts of methyl hydroquinone and 252.9 parts of toluene were introduced into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was blown in at a rate of 10 ml/min. The mixture was stirred and reacted at 110°C for 12 hours. The water generated by the reaction was an azeotropic mixture with toluene, and 12.6 parts of water were distilled out. The mixture was then cooled to room temperature, and the obtained reaction solution was neutralized with 35.35 parts of a 15% sodium hydroxide aqueous solution, followed by water washing. Subsequently, 118.1 parts of diethylene glycol monoethyl ether acetate were used to replace toluene in an evaporator and distilled off to obtain a novolac type acrylate resin solution. Next, 332.5 parts of the obtained novolac type acrylate resin solution and 1.22 parts of triphenylphosphine were introduced into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was blown in at a rate of 10 ml/min. While stirring, 60.8 parts of tetrahydrophthalic anhydride were slowly added, and the mixture was reacted at 95-101°C for 6 hours, and then taken out after cooling. In this way, a solution of acrylate resin A-1 with a solid content of 65% and a solid acid value of 87.7 mgKOH/g was obtained.

(Synthesis of Alkaline Soluble Resin A-2) In a flask equipped with a cooling tube and a stirrer, add 456 parts of bisphenol A, 228 parts of water, and 649 parts of 37% formaldehyde, keep the temperature below 40°C, add 228 parts of 25% sodium hydroxide aqueous solution, and react at 50°C for 10 hours after the addition. After the reaction is completed, cool to 40°C, keep it below 40°C and neutralize it to pH 4 with 37.5% phosphoric acid aqueous solution. Then stand and separate the water layer. After separation, add 300 parts of methyl isobutyl ketone and dissolve it uniformly, then wash it with 500 parts of distilled water 3 times, and remove water, solvent, etc. under reduced pressure at a temperature below 50°C. The obtained polyhydroxymethyl compound was dissolved in 550 parts of methanol to obtain 1230 parts of a methanol solution of the polyhydroxymethyl compound. A portion of the obtained methanol solution of the polyhydroxymethyl compound was dried in a vacuum dryer at room temperature, and the solid content was 55.2%. 500 parts of the obtained methanol solution of the polyhydroxymethyl compound and 440 parts of 2,6-xylenol were fed and uniformly dissolved at 50°C. After uniform dissolution, methanol was removed under reduced pressure at a temperature below 50°C. Subsequently, 8 parts of oxalic acid were added and reacted at 100°C for 10 hours. After the reaction was completed, the distilled portion was removed under reduced pressure at 180°C and 50 mmHg to obtain 550 parts of phenolic varnish resin A. Then, 130 parts of the above-mentioned phenolic varnish resin A, 2.6 parts of a 50% sodium hydroxide aqueous solution, and 100 parts of toluene/methyl isobutyl ketone (mass ratio = 2/1) were fed into a high pressure autoclave equipped with a thermometer, a nitrogen gas introduction device and an ethylene oxide introduction device, and a stirring device. The nitrogen gas was replaced in the system while stirring, and then the temperature was raised, and 45 parts of ethylene oxide were slowly introduced at 150°C and 8kg/ ^cm2 for reaction. The reaction lasted for about 4 hours until the gauge pressure reached 0.0kg.cm2, and ^then cooled to room temperature. 3.3 parts of a 36% hydrochloric acid aqueous solution were added and mixed into the reaction solution to neutralize the sodium hydroxide. The neutralization reaction product was diluted with toluene, washed with water three times, and the solvent was removed by evaporation to obtain an ethylene oxide adduct of novolac resin A with a hydroxyl value of 175 g/eq. This is a product in which an average of 1 mol of phenolic hydroxyl group is added to 1 equivalent of ethylene oxide. 175 parts of the ethylene oxide adduct of novolac resin A obtained in this way, 50 parts of acrylic acid, 3.0 parts of p-toluenesulfonic acid, 0.1 parts of hydroquinone monomethyl ether, and 130 parts of toluene were fed into a reactor equipped with a stirrer, a thermometer, and an air blowing tube. The reactor was stirred while blowing air in, and the temperature was raised to 115°C. The water generated by the reaction was distilled off as an azeotropic mixture with toluene. After further reaction for 4 hours, the reactor was cooled to room temperature. The obtained reaction solution was washed with 5% NaCl aqueous solution, and after toluene was distilled off under reduced pressure, diethylene glycol monoethyl ether acetate was added to obtain an acrylate resin solution with a solid content of 68%. Next, 312 parts of the obtained acrylate resin solution, 0.1 parts of hydroquinone monomethyl ether, and 0.3 parts of triphenylphosphine were added to a 4-neck flask equipped with a stirrer and a reflux cooler. The mixture was heated to 110°C, 45 parts of tetrahydrophthalic anhydride were added, and the mixture was reacted for 4 hours and removed after cooling. The carboxyl-containing photosensitive resin obtained in this way has a non-volatile content of 72% and a solid acid value of 65 mgKOH/g. The carboxyl-containing photosensitive resin is hereinafter referred to as A-2 varnish.

(Synthesis of Alkaline Soluble Photosensitive Resin A-3) In a flask equipped with a cooling tube and a stirrer, add 456 parts of bisphenol A, 228 parts of water, and 649 parts of 37% formaldehyde, keep the temperature below 40°C, add 228 parts of 25% sodium hydroxide aqueous solution, and react at 50°C for 10 hours after the addition. After the reaction is completed, cool to 40°C, keep it below 40°C and neutralize it to pH 4 with 37.5% phosphoric acid aqueous solution. Then stand it to separate the water layer. After separation, add 300 parts of methyl isobutyl ketone and dissolve it uniformly, then wash it with 500 parts of distilled water 3 times, and remove water, solvent, etc. under reduced pressure at a temperature below 50°C. The obtained polyhydroxymethyl compound was dissolved in 550 parts of methanol to obtain 1230 parts of a methanol solution of the polyhydroxymethyl compound. A portion of the obtained methanol solution of the polyhydroxymethyl compound was dried in a vacuum dryer at room temperature, and the solid content was 55.2%. 500 parts of the obtained methanol solution of the polyhydroxymethyl compound and 440 parts of 2,6-xylenol were fed and uniformly dissolved at 50°C. After uniform dissolution, methanol was removed under reduced pressure at a temperature below 50°C. Subsequently, 8 parts of oxalic acid were added and reacted at 100°C for 10 hours. After the reaction was completed, the distilled portion was removed under reduced pressure at 180°C and 50 mmHg to obtain 550 parts of phenolic varnish resin A. Then, 130 parts of the above-mentioned phenolic varnish resin A, 2.6 parts of a 50% sodium hydroxide aqueous solution, and 100 parts of toluene/methyl isobutyl ketone (mass ratio = 2/1) were fed into a high pressure autoclave equipped with a thermometer, a nitrogen gas introduction device and an ethylene oxide introduction device, and a stirring device. The nitrogen gas was replaced in the system while stirring, and then the temperature was raised, and 45 parts of ethylene oxide were slowly introduced at 150°C and 8kg/ ^cm2 for reaction. The reaction lasted for about 4 hours until the gauge pressure reached 0.0kg.cm2, and ^then cooled to room temperature. 3.3 parts of a 36% hydrochloric acid aqueous solution were added and mixed into the reaction solution to neutralize the sodium hydroxide. The neutralization reaction product was diluted with toluene, washed with water three times, and the solvent was removed by evaporation to obtain an ethylene oxide adduct of novolac resin A with a hydroxyl value of 175 g/eq. This is a product in which an average of 1 mol of phenolic hydroxyl group is added to 1 equivalent of ethylene oxide. 175 parts of the ethylene oxide adduct of novolac resin A obtained in this way, 75 parts of methacrylic acid, 3.0 parts of p-toluenesulfonic acid, 0.1 parts of hydroquinone monomethyl ether, and 130 parts of toluene were fed into a reactor equipped with a stirrer, a thermometer, and an air blowing tube, and stirred while blowing air in. The temperature was raised to 115°C, and the water generated by the reaction was distilled off as an azeotropic mixture with toluene. After further reaction for 4 hours, the reaction was cooled to room temperature. The obtained reaction solution was washed with a 5% NaCl aqueous solution, and after toluene was distilled off under reduced pressure, diethylene glycol monoethyl ether acetate was added to obtain an acrylic resin solution with a solid content of 68%. Hereinafter, the acrylic resin solution is referred to as resin solution A-3.

(Synthesis of spherical silica) 70 g of spherical silica (SFP-30M manufactured by DENKA) and 30 g of PMA (propylene glycol monomethyl ether acetate) as a solvent were mixed and dispersed to obtain an inorganic filler.

[Example and Comparative Example] According to the formula shown in Table 1, each component is mixed in the proportion (mass parts) shown in Table 1, pre-mixed with a stirrer, and then kneaded with a bead mill to prepare a hardening resin composition. In addition, the mixing amount in the table represents the solid content (non-volatile matter).

(Preparation of dry film) The hardening resin composition prepared above was applied on a PET film using an applicator in such a way that the thickness of the resin layer after drying became a specific film thickness, and dried at 80°C for 30 minutes to obtain a dry film.

(Transmittance) According to the method described in (Preparation of dry film) above, a dry film with a resin layer thickness of 20 μm was prepared after drying. The above-mentioned dry film with a resin layer thickness of 20 μm was laminated on a 2 mm thick glass substrate, and the PET film was peeled off. Then, the absorbance was measured using a spectrophotometer V-670.

(Concealment) According to the method described in (Preparation of dry film) above, dry films with a resin layer thickness of 20μm and 25μm after drying were prepared. Next, 18μm copper foil was subjected to CZ treatment (roughening treatment) at an etching rate of 1μm using MECetchBOND CZ-8101 manufactured by MERCK, and then rust-proofed using MECetchBOND CL-8300 manufactured by MERCK, forming a printed wiring board with a comb-shaped pattern with a Cu thickness of 17μm and L/S=12μm/13μm. The dry films were fully exposed using HMW680G (metal halogen lamp, scattered light) manufactured by OAK with an optimal exposure dose of 800mJ. After peeling off the PET film, the film was further irradiated with UV light at a cumulative exposure of 1000mJ, and then cured (post-cured) by heating at 160°C for 60 minutes in a heat cycle box furnace. The printed wiring board with the obtained cured film was visually evaluated for the concealment of the circuit. ◎: The Cu circuit was not visible at all in the 20μm and 25μm cured films. ○: The Cu circuit was visible in the 20μm cured film, and the Cu circuit was not visible in the 25μm cured film. ×: The Cu circuit was visible in the 20μm and 25μm cured films.

(Resolution) According to the method described in (Preparation of dry film) above, a dry film with a resin layer thickness of 20μm after drying was prepared. A 35μm copper foil was subjected to CZ treatment (roughening treatment) at an etching rate of 1μm using MECetchBOND CZ-8101 manufactured by MERCK, and then the above-mentioned dry film with a resin layer thickness of 20μm was laminated on a substrate with a 34μm copper foil subjected to rustproof treatment using MECetchBOND CL-8300 manufactured by MERCK, and exposed using a projection exposure machine UFX-2223M-APU01 that cuts off the wavelength side longer than the i-line to form an opening pattern with a diameter of 40~350nm. The peeled PET film was developed with a 1.0wt% sodium carbonate aqueous solution, and the minimum opening diameter that could be formed was confirmed by SEM. ○: The minimum diameter is less than 40μm. ×: The minimum diameter exceeds 40μm.

(Confirmation test of color tone change) According to the method described in the above (Preparation of dry film), a dry film with a resin layer thickness of 20μm after drying was prepared. A 35μm copper foil was subjected to CZ treatment (roughening treatment) at an etching rate of 1μm using MECetchBOND CZ-8101 manufactured by MERCK, and then the above-mentioned dry film with a resin layer thickness of 20μm was laminated on a substrate with a 34μm copper foil that was subjected to rustproof treatment using MECetchBOND CL-8300 manufactured by MERCK. It was fully exposed using HMW680G (metal halogen lamp, scattered light) manufactured by OAK with an optimal exposure amount of 800mJ. After peeling off the PET film, the substrate was further irradiated with UV light at a cumulative exposure of 1000 mJ. The color tone change confirmation test was conducted on the substrate after irradiation with UV light in a heat cycle box furnace under two conditions: post-curing at 150°C for 60 minutes and post-curing at 170°C for 60 minutes. The colorimeter CM-2600d manufactured by Konica Minolta was used to measure the CIE L*a*b* method in the SCI mode.

The notes in the headings of Table 1 are as follows. *1: Solution A-1 of the above-mentioned alkali-soluble resin *2: Solution A-2 of the above-mentioned alkali-soluble resin *3: Solution A-3 of the above-mentioned alkali-soluble resin *4: Neomer DA-600 manufactured by Sanyo Chemical Industries, Ltd. *5: Laromer LR8863 manufactured by BASF Japan *6: N-870-75EA manufactured by DIC Corporation *7: NC-3000H manufactured by Nippon Kayaku Co., Ltd. *8: HP-7200L manufactured by DIC Corporation *9: C.I. Pigment Red 149 *10: C.I. Pigment Yellow 147 *11: Phthalocyanine (C.I. Pigment Blue 15) *12: Carbon black *13: B-30 manufactured by Sakai Chemical Industry Co., Ltd. *14: Spherical silica synthesized above *15: IGM Omnirad TPO H manufactured by Resins, acylphosphine oxide-based photopolymerization initiator *16: JMT-784 manufactured by DSKH Co., Ltd., Japan, titaniumocene-based photopolymerization initiator *17: Melamine *18: DICY (dicyanamide) *19: QUINO POWER QS-30 manufactured by Kawasaki Chemical Co., Ltd.

From the results shown in the above table, it can be seen that the curable resin composition of the present invention has excellent concealment and resolution. In contrast, the concealment evaluation result of Comparative Example 1 is poor. The resolution evaluation results of Comparative Examples 2 and 3 are poor. The concealment evaluation result of Comparative Example 4 is poor. The resolution evaluation results of Comparative Examples 5, 6, and 7 are poor. Moreover, color tone changes were seen before and after heating in Examples 1 to 4 and Comparative Example 3. Moreover, the concealment evaluation results of Comparative Examples 1 and 4 are poor, and the resolution evaluation results of Comparative Examples 2, 5, 6, and 7 are poor, so the color tone change was not confirmed. As a result, the color tone of Examples 1 to 4 before and after heating changes less. In contrast, the color tone of Comparative Example 3 changes more when compared with Examples 1 to 4. Although not shown in the table, as Comparative Example 8, the components other than the pigment are prepared in the same amount as Comparative Example 2, and the pigment does not contain black, yellow and red, but only 1.89 parts by mass of blue. Regarding Comparative Example 8, although the result of evaluating the resolution is improved to 30μm, the evaluation result of the concealment is ×, so no other evaluation is performed.

Claims (4)

A curable resin composition comprising (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a thermosetting resin, and (D) a coloring agent, wherein the curable resin composition is formed on copper having a surface subjected to a CZ treatment, wherein the transmittance of a dry coating film (film thickness 20 μm) of the curable resin composition formed on a glass substrate having a thickness of 2 mm is 30 to 50% at a wavelength of 430 nm, 28 to 45% at a wavelength of 530 nm, 5% or more at a wavelength of 365 nm, and 12% or less at a wavelength of 720 nm. A dry film comprises a resin layer obtained from the curable resin composition described in claim 1. A hardened product obtained by hardening the hardening resin composition described in claim 1 or the resin layer of the dry film described in claim 2. A printed wiring board comprises the cured article as recited in claim 3.