Melamine-free alkaline developable resin composition, dry film, cured product, and electronic component having cured product

Abstract

Provided are: a melamine-free alkaline developable resin composition which has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance in a cured product thereof, and which has excellent drying management range, sensitivity, and resolution; a dry film; a cured product; and an electronic component having the cured product. The composition contains an epoxy resin, a carboxyl-containing vinyl ester resin, a photopolymerization initiator, a photosensitive monomer, an inorganic filler and a hydroxyl-containing compound component, and the carboxyl-containing vinyl ester resin and the inorganic filler, and the epoxy resin and the photosensitive monomer are respectively contained in different resin compositions. The hydroxyl group-containing compound component has a pH value of 4.0 or more and 5.5 or less, the hydroxyl group-containing compound component contains a hydroxyl group-containing compound having at least one hydroxyl group in the molecule, and the content of the hydroxyl group-containing compound component is 1.2-7.8 parts by mass per 100 parts by mass of the carboxyl group-containing vinyl ester resin in terms of solid content.

Description

Technical Field

[0001] The present invention relates to a melamine-free alkaline developing resin composition, a dry film, a cured product, and an electronic component having the cured product. In particular, the present invention relates to a melamine-free alkaline developing resin composition, a cured product thereof suitable for a printed circuit board, such as a solder resist, and an electronic component having the cured product. Background Art

[0002] In the formation of permanent coatings such as solder mask in the manufacture of printed circuit boards, curable resin compositions are usually used. As such curable resin compositions, dry film type compositions, liquid compositions, etc. have been developed. Furthermore, in order to be used for miniaturization of electronic components, high-precision design structures, and complex manufacturing methods, it is also expected that the curable resin composition can be patterned by applying the principle of photography (photolithography), so that fine processing can be performed. In recent years, from the perspective of environmental countermeasures, alkaline developing types that can be developed in dilute weak alkaline aqueous solutions have become mainstream.

[0003] Solder resist (also called solder resist ink) has been used as a protective material for circuit boards on printed circuit boards. Alkaline-developable photosensitive compositions are now widely used as solder resists in the actual manufacture of printed circuit boards. As a method for forming a solder resist using the solder resist, a solder resist layer is applied to a substrate with a circuit formed thereon and dried, and then a photomask is vacuum-sealed for exposure, which has become the mainstream.

[0004] Currently, the solder mask inks on the market usually contain melamine, which acts as a thermosetting agent and antioxidant to improve the ink's acid and alkali resistance, metal plating resistance, adhesion and hardness. However, there are many problems with melamine in the ink. It will volatilize during the soldering process (260°C), and based on the EU REACH regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals), melamine belongs to the SVHC (Substances of Very High Concern) category of environmentally controlled substances.

[0005] Patent Document 1 produces a highly sensitive epoxy solder resist acrylic oligomer containing a hydroxyl group, a carboxyl group and a double bond and having an acid value and epoxy equivalent in a specific range, thereby improving the sensitivity of solder resist ink. However, when the epoxy solder resist acrylic oligomer is used to manufacture ink, a conventional curing agent is still used.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent document 1: CN114262424A Summary of the invention

[0009] Technical Problems to be Solved by the Invention

[0010] In the past, solder resist inks usually contained melamine as a thermosetting agent and antioxidant. As environmental protection requirements become increasingly stringent, it is hoped that an alkaline-developable resin composition with excellent drying control range, sensitivity, and resolution can be prepared without using melamine, and its cured product has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance.

[0011] Therefore, an object of the present invention is to provide an alkali-developable resin composition whose cured product has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance and solvent resistance and is excellent in drying control range, sensitivity and resolution.

[0012] Another object of the present invention is to provide a dry film and a cured product having excellent properties as described above obtained by using such an alkaline developing solder resist composition, and a printed wiring board having a cured film such as a solder resist formed from the dry film and the cured product.

[0013] Solutions for solving problems

[0014] The present inventors have conducted intensive research and found that the above-mentioned problems can be solved by the following alkaline-developable resin composition. The alkaline-developable resin composition is composed of at least a two-component system resin composition, characterized in that the alkaline-developable resin composition contains: an epoxy resin, a carboxyl group-containing vinyl ester resin, a photopolymerization initiator, a photosensitive monomer, an inorganic filler and a hydroxyl-containing compound component.

[0015] The carboxyl vinyl ester resin and the inorganic filler are contained in different resin compositions from the epoxy resin and the photosensitive monomer.

[0016] The pH value of the hydroxyl-containing compound component is greater than or equal to 4.0 and less than or equal to 5.5. The hydroxyl-containing compound component includes a hydroxyl-containing compound having at least one hydroxyl group in the molecule. The content of the hydroxyl-containing compound component is 1.2 to 7.8 parts by mass relative to 100 parts by mass of the carboxyl-containing vinyl ester resin calculated as a solid content.

[0017] Among them, a preferred embodiment of the present invention relates to an alkaline-developable resin composition, characterized in that the hydroxyl-containing compound having at least one hydroxyl group in the molecule is at least one or more selected from the group consisting of alcohols, phenols, ethers, esters or polymers.

[0018] Furthermore, a preferred embodiment of the present invention relates to an alkali-developable resin composition, wherein the hydroxyl-containing compound having at least one hydroxyl group in a molecule is a propylene glycol compound and / or a propylene glycol ether compound.

[0019] Furthermore, a more preferred embodiment of the present invention relates to an alkali-developable resin composition, wherein the hydroxyl group-containing compound component having at least one hydroxyl group in a molecule has an acid value of 10 to 100 mgKOH / g.

[0020] Furthermore, a more preferred embodiment of the present invention relates to an alkali-developable resin composition, wherein the molecular weight of the hydroxyl group-containing compound having at least one hydroxyl group in the molecule is within a range of 500 to 5,000.

[0021] Furthermore, a further preferred embodiment of the present invention relates to an alkaline-developable resin composition, characterized in that the carboxyl vinyl ester resin, the photopolymerization initiator, the inorganic filler and the hydroxyl-containing compound component are contained in different resin compositions from the epoxy resin and the photosensitive monomer.

[0022] Moreover, another aspect of the present invention relates to a dry film obtained by applying the above-mentioned alkali-developable resin composition on a carrier film and drying the resulting film.

[0023] Still another aspect of the present invention relates to the above-mentioned alkali-developable resin composition, characterized in that the composition is used as a material for a solder resist.

[0024] Still another aspect of the present invention relates to: a cured product characterized in that it is obtained by curing an alkaline-developable resin composition; a cured product characterized in that it is obtained by curing a resin layer of a dry film; and an electronic component characterized in that it has these cured products.

[0025] Effects of the Invention

[0026] According to the present invention, there can be provided an alkali-developable resin composition whose cured product has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance and solvent resistance and which is excellent in drying control range, sensitivity and resolution.

[0027] Furthermore, the present invention can provide a dry film and a cured product having excellent properties as described above obtained by using such an alkaline-developable resin composition, and an electronic component such as a printed wiring board in which a cured film such as a solder resist is formed from the dry film or the cured product. DETAILED DESCRIPTION

[0028] The alkaline developing resin composition of the present invention is preferably composed of at least a two-component system resin composition. For example, a two-component system can be cited in which one resin composition is used as a main agent composition and the other resin composition is used as a curing agent composition. In this case, for example, the carboxyl vinyl ester resin and the inorganic filler are contained in different resin compositions from the epoxy resin and the photosensitive monomer. Preferably, the main agent composition is composed of at least a carboxyl vinyl ester resin, a photopolymerization initiator, an inorganic filler and a hydroxyl-containing compound component, and the curing agent composition is composed of at least an epoxy resin and a photosensitive monomer.

[0029] Here, from the viewpoint of preventing chemical reactions during storage, it is preferred that the epoxy resin and the carboxyl group-containing vinyl ester resin are directly contained in different compositions, and the photosensitive monomer and the photopolymerization initiator are directly contained in different compositions.

[0030] Hereinafter, each component constituting the alkali-developable resin composition of the present invention will be described.

[0031] Epoxy resin

[0032] The epoxy resin functions as a thermosetting component in the alkaline-developable resin composition to form a cured product.

[0033] As such an epoxy resin, a known and commonly used multifunctional epoxy resin having at least two epoxy groups in one molecule can be used.

[0034] Epoxy resin can be liquid at room temperature, or solid or even semi-solid.

[0035] As the multifunctional epoxy resin, preferably bisphenol A type epoxy resin; brominated epoxy resin; 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; bixylenol type or biphenol type epoxy resin or a mixture thereof; bisphenol S type epoxy resin; bisphenol A novolac type epoxy resin; tetrahydroxyphenylethane type epoxy resin; Resin; heterocyclic epoxy resin; diglycidyl phthalate resin; tetraglycidyl ditoluoyl ethane resin; naphthyl-containing epoxy resin; epoxy resin having a dicyclopentadiene skeleton; glycidyl methacrylate copolymer epoxy resin; copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivative; CTBN-modified epoxy resin, epoxy resin having an isocyanurate ring, etc., but of course not limited to these.

[0036] These epoxy resins can be used alone or in combination of two or more.

[0037] The epoxy resin that is solid or semi-solid at room temperature can also be a known and commonly used one. For example, as the epoxy resin that is solid at room temperature, bisphenol A type epoxy resin (jER1001 manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resin (jER4004P manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resin (HP-4700 manufactured by DIC Corporation), multifunctional solid epoxy resin containing naphthalene skeleton (NC-7000 manufactured by Nippon Kayaku Co., Ltd.), trisphenol epoxy resin (EPPN-502H manufactured by Nippon Kayaku Co., Ltd.), multifunctional solid epoxy resin containing dicyclopentadiene skeleton (Epiclon manufactured by DIC Corporation) HP-7200), phosphorus-containing epoxy resin (TX0712 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), tris(2,3-epoxypropyl)isocyanurate (TEPIC manufactured by Nissan Chemical Industries, Ltd.), and epoxy resins that are semi-solid at room temperature include bisphenol A type epoxy resin (jER834 manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resin (HP-4032 manufactured by DIC Corporation), etc.

[0038] Here, in the present invention, being solid or semisolid at room temperature means being solid or semisolid at 15° C. Determination of solid or semisolid can be made according to Annex 2 “Method for Confirming Liquid State” of the Ministerial Ordinance on Tests and Properties of Dangerous Substances (Ministerial Ordinance No. 1, 1991).

[0039] As the biphenyl type epoxy resin, a known and commonly used multifunctional epoxy resin having a biphenyl skeleton can be used, for example, a multifunctional solid epoxy resin containing a biphenyl skeleton (NC-3000H and NC-3000 manufactured by Nippon Kayaku Co., Ltd.), a biphenyl type epoxy resin (YX-4000 and YL-6121HA manufactured by Mitsubishi Chemical Corporation), etc. can be mentioned.

[0040] Examples of the novolac epoxy resin include cresol novolac epoxy resin (Epiclon N-690 manufactured by DIC Corporation), phenol novolac epoxy resin (Epiclon N-770 manufactured by DIC Corporation, jER152 manufactured by Mitsubishi Chemical Corporation), and the like.

[0041] The content of the epoxy resin described above is preferably in the range of about 30 to 100 parts by mass, more preferably 40 to 90 parts by mass, and even more preferably 50 to 85 parts by mass, relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin in terms of solid content.

[0042] Carboxylic vinyl ester resin

[0043] As the carboxyl group-containing vinyl ester resin used in the present invention, a carboxyl group-containing vinyl ester resin having an ethylenically unsaturated double bond in the molecule is particularly preferred from the viewpoint of being able to impart alkali developability, photocurability, and development resistance. For example, a resin using an epoxy resin as a starting material, a polyurethane resin having a carbamate skeleton, a copolymer resin having a copolymer structure of an unsaturated carboxylic acid, and a resin using a phenol compound as a starting material. Specific examples of the carboxyl group-containing vinyl ester resin are shown below.

[0044] (1) a carboxyl group-containing vinyl ester resin obtained by reacting a reaction product of a polyfunctional epoxy compound and an unsaturated monocarboxylic acid with a compound having at least one alcoholic hydroxyl group and one reactive group other than the alcoholic hydroxyl group that reacts with an epoxy group in one molecule, with a saturated or unsaturated polybasic acid anhydride;

[0045] (2) a carboxyl-containing vinyl ester resin obtained by reacting an unsaturated monocarboxylic acid with a polyfunctional epoxy resin and then reacting the unsaturated monocarboxylic acid with a polyacid anhydride to obtain a carboxyl-containing resin, and then reacting the unsaturated monocarboxylic acid with a polyfunctional epoxy resin to obtain a carboxyl-containing vinyl ester resin;

[0046] (3) a carboxyl group-containing vinyl ester resin obtained by reacting a polyfunctional epoxy resin such as a phenol novolac epoxy resin, a cresol novolac epoxy resin, a bisphenol A cresol novolac epoxy resin, or a dicyclopentadiene cresol novolac epoxy resin with (meth)acrylic acid, and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to a hydroxyl group present in a side chain;

[0047] (4) reacting the multifunctional epoxy resin obtained by further epoxidizing the hydroxyl groups of the multifunctional epoxy resin in (3) with epichlorohydrin with (meth)acrylic acid, and adding a polybasic acid anhydride to the generated hydroxyl groups to obtain a carboxyl group-containing vinyl ester resin;

[0048] (5) Carboxyl-containing vinyl ester resins obtained by adding cyclic ethers such as ethylene oxide or cyclic carbonates such as propylene carbonate to polyfunctional phenol compounds such as novolac resins, partially esterifying the resulting hydroxyl groups with (meth)acrylic acid, and reacting the remaining hydroxyl groups with polyacid anhydrides;

[0049] (6) Carboxyl group-containing vinyl ester resins obtained by further adding a compound having one epoxy group and one or more (meth)acryloyl groups in the molecule such as glycidyl (meth)acrylate or a-methylglycidyl (meth)acrylate to any of the resins described in (3) to (5).

[0050] Among these examples, particularly preferred are cresol novolac type and phenol novolac type carboxyl group-containing vinyl ester resins, namely, the carboxyl group-containing vinyl ester resins of (3), (4), (5) and (6) above.

[0051] It should be noted that, in the present specification, (meth)acrylate is a term collectively referring to acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

[0052] Since the carboxyl group-containing vinyl ester resin described above has a plurality of free carboxyl groups on the side chains of the main chain polymer, it can be developed using a dilute alkaline aqueous solution.

[0053] The acid value of the carboxyl group-containing vinyl ester 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 is less than 40 mgKOH / g, alkali development is difficult, while when it exceeds 200 mgKOH / g, dissolution of the exposed portion by the developer is promoted, so that the line becomes thinner than necessary, and sometimes the exposed portion and the unexposed portion are dissolved and peeled by the developer indiscriminately, making it difficult to draw a normal resist pattern, which is not preferred.

[0054] In addition, the weight average molecular weight of the above-mentioned carboxyl group-containing vinyl ester resin varies depending on the resin skeleton, and is generally preferably in the range of 2000 to 150000, and more preferably in the range of 5000 to 100000. When the weight average molecular weight is less than 2000, the coating on the substrate and the non-tackiness (dry to touch) after drying may be deteriorated, and the moisture resistance of the coating film after exposure may deteriorate, the film may be reduced during development, and the resolution may be greatly deteriorated. On the other hand, when the weight average molecular weight exceeds 150000, the developability may be significantly deteriorated and the storage stability may be deteriorated.

[0055] Photopolymerization initiator

[0056] Examples of the photopolymerization initiator include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bisacylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide; Phosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, methyl 2,4,6-trimethylbenzoylphenylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, isopropyl pivaloylphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and other monoacylphosphine oxides; 1-hydroxy-cyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one and other hydroxyacetophenones; benzoin, benzyl, benzoin methyl ether , benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether and other benzoins; benzoin alkyl ethers; benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis(diethylamino)benzophenone and other benzophenones; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methyl Acetophenones such as 1-[4-(4-morpholinyl)phenyl)methyl)-1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone, etc.; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, etc.; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone, etc.; ketals such as acetophenone dimethyl ketal, benzil dimethyl ketal, etc.; benzoic acid esters such as ethyl 4-dimethylamino benzoate, 2-(dimethylamino)ethyl benzoate, and ethyl p-dimethylbenzoate;Oxime esters such as 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyloxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-ethanone 1-(O-acetyloxime); titanocenes 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-pyrrol-1-yl)ethyl)phenyl]titanium; 2-nitrofluorene phenyl disulfide, butyroquinone, anisoquinone ether, azobisisobutyronitrile, tetramethylthiuram disulfide, etc. The photopolymerization initiator may be used alone or in combination of two or more. ;

[0057] The content of the photopolymerization initiator is preferably 5 to 25 parts by mass, more preferably 8 to 20 parts by mass, relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin in terms of solid content. When the content is 5 parts by mass or more, the surface curability becomes good, and when the content is 25 parts by mass or less, halation is less likely to occur, resulting in good resolution.

[0058] Photosensitive monomer

[0059] The alkaline developing resin composition capable of forming the cured product of the present invention may contain a known and commonly used photosensitive monomer. The photosensitive monomer may be, for example, a compound having one or more ethylenically unsaturated groups in the molecule. Such a photosensitive monomer contributes to the photocuring of the carboxyl vinyl ester resin based on active energy ray irradiation (when containing an ethylenically unsaturated group), thereby curing the alkaline developing resin composition.

[0060] The photosensitive monomer preferably used in the present invention includes, for example, methyl α-(allyloxymethyl)acrylate, or diol diacrylates such as 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, and 1,10-decanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, etc. Diol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, diol diacrylate obtained by adding at least one of ethylene oxide and propylene oxide to neopentyl glycol, diol diacrylate such as caprolactone-modified hydroxypivalic acid neopentyl glycol diacrylate, bisphenol A EO adduct diacrylate, bisphenol A PO adduct diacrylate, tricyclodecane dimethanol diacrylate, hydrogenated dicyclopentadienyl diacrylate, cyclohexyl diacrylate, etc. Diacrylates having a cyclic structure, or bifunctional (meth)acrylates such as methacrylate monomers corresponding thereto, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolmethane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, epichlorohydrin-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, tetramethylolmethane tetraacrylate, ethylene oxide-modified phosphoric acid triacrylate, epichlorohydrin-modified glycerol triacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, or polyfunctional acrylates represented by silsesquioxane-modified products thereof, or methacrylate monomers corresponding thereto, trifunctional methacrylates, polyfunctional (meth)acrylates such as ε-caprolactone-modified tris(acryloyloxyethyl)isocyanurate, or combinations of two or more thereof.

[0061] The content of the photosensitive monomer is preferably in the range of 5 to 50 parts by mass, more preferably 10 to 45 parts by mass, and even more preferably 15 to 40 parts by mass, based on 100 parts by mass of the carboxyl group-containing vinyl ester resin in terms of solid content.

[0062] When the content of the photosensitive monomer is within such a range, the alkali-developable resin composition has sufficient photocurability, patterning is further improved during development, and dryness to touch is also improved.

[0063] Inorganic fillers

[0064] In the present invention, the inorganic filler may be used alone or in combination of two or more.

[0065] The amount of the inorganic filler is preferably in the range of 10 to 100 parts by mass, more preferably in the range of 15 to 80 parts by mass, and further preferably in the range of 20 to 60 parts by mass, relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin in terms of solid content. When the amount of the inorganic filler is 10 parts by mass or more, there is a tendency to obtain a cured film having better resistance to soldering heat, insulation reliability, reflectivity, and heat discoloration resistance. When the amount of the inorganic filler is 80 parts by mass or less, there is a tendency to obtain an alkaline developing resin composition having better degassing properties, resolution, and deep curing properties.

[0066] Examples of the inorganic filler include titanium oxide, silicon dioxide, barium sulfate, barium titanate, Neuburg silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, etc. Among them, it is preferred to contain at least any one of talc, silicon dioxide, and barium sulfate, which can suppress the curing shrinkage of the cured product of the alkaline developing type resin composition and improve the properties such as adhesion, hardness, and reflectivity.

[0067] From the viewpoint of improving the mechanical properties, heat resistance, processability and chemical resistance of the cured product, an inorganic filler is preferably contained in the main agent. As the inorganic filler, at least one of silicon dioxide and barium sulfate is preferred.

[0068] The inorganic filler may be surface-treated and used. More preferably, the surface of the inorganic filler is surface-treated to introduce a curable reactive group.

[0069] Here, the curing reactive group refers to a group that undergoes a curing reaction with an epoxy resin or a carboxyl group-containing vinyl ester resin, and may be a photocuring reactive group or a thermosetting reactive group. Examples of the photocuring reactive group include methacryloyl, acryloyl, vinyl, and styryl groups, and examples of the thermosetting reactive group include epoxy, amino, hydroxyl, carboxyl, isocyanate, imino, oxetanyl, mercapto, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, and oxazoline groups.

[0070] The method for introducing curable reactive groups into the surface of the inorganic filler is not particularly limited, and the introduction can be carried out using a known and commonly used method, and the surface of the inorganic filler can be treated with a surface treatment agent having a curable reactive group, for example, a coupling agent having a curable reactive group as an organic group. As coupling agents, silane coupling agents, titanium coupling agents, zirconium coupling agents, aluminum coupling agents, etc. can be used. It should be noted that, as inorganic fillers treated with surfaces without curable reactive groups, for example, silica-alumina surface treatment, titanate coupling agent treatment, aluminate coupling agent treatment, organically treated inorganic fillers, etc. can be cited.

[0071] The average particle size (D50) of the inorganic filler is 2000 nm or less, more preferably 1200 nm or less. The lower limit thereof is preferably 0.1 nm or more in terms of the average particle size (D50).

[0072] The smaller the average particle size of the inorganic filler, the more diffuse reflection during light irradiation is suppressed, and the micro-processing of the cured product pattern can be facilitated. The average particle size (D50) can be obtained using a laser diffraction particle size distribution measuring device and a measuring device based on a dynamic light scattering method. As a measuring device based on a laser diffraction method, MicrotracMT3300EXII made by MicrotracBEL Inc. can be cited, and as a measuring device based on a dynamic light scattering method, Nanotrac Wave II UT151 made by MicrotracBEL Inc. can be cited.

[0073] Hydroxyl compound components

[0074] The alkaline-developable resin composition of the present invention achieves the above-mentioned object of the present invention by using a hydroxyl-containing compound component having a specific pH value range in the main agent component.

[0075] In detail, the inventors have found through active research that melamine has the ability to donate electrons, absorb free radicals, and play a certain role in inhibiting polymerization in the process of photoinitiated polymerization, thereby reducing the sensitivity. By replacing melamine with a hydroxyl-containing compound component with a pH value in a specific range, it is possible to slightly reduce its acid resistance and metal plating resistance while ensuring that the drying management range, resolution, alkali resistance, solvent resistance, etc. remain unchanged, but at the same time improve the sensitivity. On this basis, unexpectedly, adding a hydroxyl-containing compound component in a specific pH range at a specific content can further improve acid resistance and metal plating resistance.

[0076] From the perspective of achieving the above object of the present invention, the pH range of the hydroxyl compound component is 4.0 to 5.5, preferably 4.0 to 5.2, more preferably 4.0 to 5.0. The pH value is measured according to DIN 19268. In addition, the acid value of the hydroxyl compound is 10 to 100 mgKOH / g, preferably 20 to 80 mgKOH / g, more preferably 25 to 60 mgKOH / g.

[0077] As long as the pH value of the hydroxyl-containing compound component is within the above range, any hydroxyl-containing compound having at least one hydroxyl group in the molecule (hereinafter sometimes referred to as "hydroxyl-containing compound") can be used. For example, a substance having one or more alcoholic hydroxyl groups and / or phenolic hydroxyl groups in the molecule. More specifically, for example, it can be selected from alcohols (including monohydric alcohols and / or polyhydric alcohols), phenols (including monohydric phenols and / or polyhydric phenols), ethers (including ethers formed by monohydric alcohols and / or polyhydric alcohols, ethers formed by monohydric phenols or polyhydric phenols), esters (including esters formed by monohydric alcohols and / or polyhydric alcohols, esters formed by monohydric phenols or polyhydric phenols), polymers having hydroxyl groups on the side chains and / or ends, etc. These hydroxyl-containing compounds can be used alone or in combination of two or more. The hydroxyl-containing compound is preferably a polymer having hydroxyl groups on the side chains and / or ends, and more preferably a polymer having hydroxyl groups and carboxyl groups on the side chains and / or ends.

[0078] Without affecting the purpose of the present invention, the main chain and / or side chain of the hydroxyl-containing compound may optionally contain other substituents, for example, alkyl (preferably carbon number 1-8, more preferably carbon number 1-4), alkoxy (preferably carbon number 1-8, more preferably carbon number 1-4), alkenyl (preferably carbon number 1-8, more preferably carbon number 1-4), alkynyl (preferably carbon number 1-8, more preferably carbon number 1-4), amino, halogen atom, amine (N atom is preferably substituted by alkyl group with carbon number 1-8, more preferably substituted by alkyl group with carbon number 1-4), carboxyl, etc.

[0079] The hydroxyl compound component may also contain other ingredients, such as solvents, without affecting the purpose of the present invention.

[0080] The content of the hydroxyl compound component in the specific pH range is 1.2 to 7.8 parts by mass, and more preferably 1.5 to 6 parts by mass, relative to 100 parts by mass of the carboxyl vinyl ester resin in terms of solid content. If the content is too low, there is still room for improvement in acid resistance and metal plating resistance. If the content is too high, there is a tendency for acid resistance and pencil hardness to become poor. By adding a hydroxyl compound component in a specific pH range within the above-mentioned content range, the alkaline developing resin composition has excellent drying management range, sensitivity, and resolution, and the cured product has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance. In particular, unexpectedly, acid resistance and metal plating resistance are further improved compared to when melamine is used.

[0081] From the perspective of further facilitating the purpose of the present invention, the molecular weight of the hydroxyl-containing compound is preferably 500 to 5000, more preferably 1000 to 4000, and further preferably 1500 to 3000 in terms of number average molecular weight. It is preferably 1000 to 6000, more preferably 2000 to 5000, and further preferably 3000 to 4000 in terms of weight average molecular weight.

[0082] Examples of commercially available products of the hydroxyl compound component within the specific pH range include TECH-7200 (Shanghai Tiger Polymer Technology Co., Ltd.).

[0083] Solvents

[0084] In the present invention, for general purposes, such as for preparing each component system of the alkali-developable resin composition and adjusting the viscosity thereof, a solvent may be used in at least one component system.

[0085] As mentioned above, conventional organic solvents can be used, and examples thereof include: ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoether (DPM), dipropylene glycol diethyl ether, and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate (CA), butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, solvent naphtha, and heavy aromatic solvent naphtha, etc.

[0086] These solvents can be used alone or in combination of two or more.

[0087] The content of the solvent in the main agent composition of the alkali-developable resin composition of the present invention is preferably in the range of 25 to 110 parts by mass relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin in terms of solid content.

[0088] Other Ingredients

[0089] It is a matter of course that further additives may be blended as other components in the alkali-developable resin composition of the present invention as necessary within the scope not departing from the purpose of the present invention.

[0090] Examples of such components include colorants such as pigments and dyes, thermal inhibitors, ultraviolet absorbers, plasticizers, flame retardants, antistatic agents, antioxidants, antibacterial / antifungal agents, defoaming agents, leveling agents, anti-sag agents, thickeners, adhesion-imparting agents, thixotropy-imparting agents, photoinitiator aids, sensitizers, photobase generators, thermoplastic resins, elastomers, organic fillers, release agents, surface treatment agents, dispersants, dispersing aids, surface modifiers, stabilizers, phosphors, cellulose resins, and the like.

[0091] The base composition and the curing agent composition of the alkali-developable resin composition of the present invention can be prepared by mixing and dispersing the respective components in predetermined amounts, for example, using a three-roll mill or the like.

[0092] Dry film

[0093] A dry film can be prepared from the alkali-developable resin composition of the present invention.

[0094] The dry film of the present invention has a resin layer, and the resin layer is obtained by coating the alkaline developing resin composition of the present invention on a carrier film and drying. When forming a dry film, first, in the case of a two-component system, the main agent composition and the curing agent composition are fully mixed with each other to obtain the alkaline developing resin composition of the present invention, and then the composition is diluted directly or as needed with a high boiling point solvent to adjust to an appropriate viscosity, and then coated on the carrier film to a uniform thickness using a comma coater, a knife coater, a lip coater, a rod coater, an extrusion coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater, etc. Thereafter, the coated composition is dried usually at a temperature of 50 to 130° C. for 1 to 30 minutes to form a resin layer. There is no particular restriction on the coating film thickness, and it is usually appropriately selected in the range of 10 to 150 μm, preferably 20 to 60 μm, based on the film thickness after drying.

[0095] As the carrier film, a plastic film is 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, and is usually appropriately selected within the range of 10 to 150 μm.

[0096] After forming the resin layer formed of the alkaline developing resin composition of the present invention on the carrier film, it is preferred to further laminate a peelable cover film on the surface of the resin layer in order to prevent dust from adhering to the surface of the resin layer. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, etc. can be used. As the cover film, any film can be used as long as it is smaller than the adhesion between the resin layer and the carrier film when the cover film is peeled off.

[0097] It should be noted that in the present invention, the alkaline developing resin composition of the present invention may be applied to 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, when preparing a dry film in the present invention, as a thin film to which the curable composition of the present invention is applied, either a carrier film or a cover film may be used.

[0098] Here, the alkaline developing resin composition of the present invention is adjusted to a viscosity suitable for the coating method using a high boiling point solvent, for example, and applied to a substrate by a dip coating method, flow coating method, roll coating method, rod coating method, screen printing method, curtain coating method, etc., and then the high boiling point solvent contained in the composition is volatilized and dried (temporary drying) at a temperature of about 60 to 100° C., thereby forming a non-sticky resin layer. In addition, in the case of a dry film formed by applying the above composition on a carrier film or a cover film and drying and winding it in the form of a film, the resin layer can be formed by laminating the composition layer on the substrate in a manner that the layer of the present invention is in contact with the substrate using a laminator, etc., and then peeling off the carrier film.

[0099] As the above-mentioned substrate, in addition to printed circuit boards and flexible printed circuit boards with circuits pre-formed with copper or the like, there can also be cited: 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 plates, etc. The copper-clad laminates use materials such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven fabric epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, and copper-clad laminates for high-frequency circuits using fluorine, polyethylene, polyphenylene ether (polyphenylene oxide), cyanate, etc.

[0100] Cured material

[0101] When the alkaline developing resin composition of the present invention is used to form a cured product, the composition is applied to a substrate, the solvent is evaporated and dried, and a resin layer is obtained. The obtained resin layer is exposed (light irradiated), so that the exposed part (the part irradiated with light) is cured. Specifically, by contact or non-contact method, active energy rays are selectively used for exposure through a photomask with a pattern, or a laser direct exposure machine is used for direct pattern exposure, and an alkaline aqueous solution (for example, a 0.3-3 mass % sodium carbonate aqueous solution) is used to develop the unexposed part, thereby forming an anti-etching pattern. Further heating to a temperature of about 100-180° C. and heat curing (post-curing) is performed, so that a cured film (cured product) with excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical properties can be formed.

[0102] The volatilization drying or thermal curing when forming the above-mentioned cured product can be carried out, for example, using a hot air circulation drying furnace, IR furnace, hot plate, convection oven, etc. (using a device with a heat source that uses steam to heat the air, a method of making the hot air in the dryer contact by convection, and a method of blowing it onto the support using a nozzle).

[0103] In addition, as an exposure machine used in the above-mentioned active energy ray irradiation, any device that irradiates ultraviolet rays in the range of 350 to 450 nm and is equipped with a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc., can be used. Furthermore, a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser using CAD data from a computer) can also be used. As a lamp light source or a laser light source of a direct drawing machine, the maximum wavelength can be in the range of 350 to 410 nm. The exposure amount used for image formation varies depending on the film thickness, etc., and can usually be set to 20 to 1000 mJ / cm 2 , preferably can be set to 20 to 800 mJ / cm 2 within the range.

[0104] Next, as a development step, the dried coating film after the exposure step is treated with a developer, thereby removing the unexposed portion of the coating film and forming a pattern film of the curable composition of the present invention.

[0105] Here, as the method used in the developing step, an immersion method, a shower method, a spray method, a brushing method, etc. can be used. As a developer, a sodium carbonate aqueous solution with a mass concentration of 0.5 to 5% can be used, and other alkaline aqueous solutions can also be used, for example: alkaline aqueous solutions of potassium hydroxide, sodium hydroxide, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc.

[0106] In this development step, the temperature of the developer is 20 to 40° C. and the development time is within 180 seconds.

[0107] In the development step, the obtained pattern film is washed with a rinse liquid as required. As the rinse liquid, distilled water, methanol, ethanol, isopropyl alcohol, etc. can be used alone or in combination.

[0108] Electronic components

[0109] The present invention can also provide an electronic component comprising the above-mentioned cured product.

[0110] The alkaline-developable resin composition or dry film of the present invention can be used for protective films, electrical insulating layers, sealing materials for built-in electronic components, component embedding layers, adhesive layers for fixing electronic components, etc. of printed circuit boards, semiconductor elements, etc., and is particularly suitable for high-density wiring requiring low dielectric constant and low dielectric loss tangent, electronic components for processing high-frequency signals, and electronic components for vehicles and robots requiring high temperature and long-term reliability.

[0111] It should be noted that the electronic components in the present invention refer to components used in electronic circuits, including active components such as printed circuit boards, transistors, light-emitting diodes, laser diodes, etc., as well as passive components such as resistors, capacitors, inductors, connectors, etc.

[0112] Hereinafter, one embodiment of the present invention will be specifically described based on the examples, but it is of course not intended to limit the scope of the invention according to the claims of the present invention.

[0113] In addition, unless otherwise specified, "parts" and "%" shown are based on mass.

[0114] Example

[0115] [Synthesis Example: Synthesis of Carboxyl Group-Containing Vinyl Ester Resin]

[0116] Into an autoclave equipped with a thermometer, a nitrogen gas introduction device and an alkylene oxide introduction device, 119.4 parts of cresol novolac resin (Shonol CRG-951 manufactured by Aica Kogyo Co.. Ltd., OH equivalent: 119.4), 1.19 parts of potassium hydroxide, and 119.4 parts of toluene were introduced, and the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Then, 63.8 parts of propylene oxide was slowly added dropwise at 125 to 132°C and 0 to 4.8 kg / cm 2 The reaction was carried out for 16 hours. Afterwards, the mixture was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added and mixed to the reaction solution to neutralize potassium hydroxide, thereby obtaining a propylene oxide reaction solution of a novolac type cresol resin having a nonvolatile content of 62.1% and a hydroxyl value of 182.2 mgKOH / g (307.9 g / eq.). On average, 1.08 mol of propylene oxide was added per 1 equivalent of phenolic hydroxyl groups.

[0117] Into a reactor equipped with a stirrer, a thermometer, and an air blowing tube, 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 methylhydroquinone, and 252.9 parts of toluene were introduced, and air was blown in at a rate of 10 ml / min, and the mixture was reacted at 110°C for 12 hours while stirring. 12.6 parts of water generated by the reaction were distilled out as an azeotropic mixture with toluene. After that, the reaction solution was cooled to room temperature, neutralized with 35.35 parts of a 15% sodium hydroxide aqueous solution, and then washed with water. After that, toluene was replaced with 118.1 parts of diethylene glycol monoethyl ether acetate in an evaporator, and distilled off to obtain a novolac type acrylate resin solution.

[0118] 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. 60.8 parts of tetrahydrophthalic anhydride were slowly added while stirring, and the mixture was reacted at 95-101° C. for 6 hours, and then cooled and taken out. In this way, a carboxyl group-containing vinyl ester resin having a solid content of 65% and an acid value of 87.7 mgKOH / g of the solid content was obtained.

[0119] [Examples 1 to 3 and Comparative Examples 1 to 8]

[0120] The components shown in Table 1 were pre-mixed in a stirrer in various amounts and then kneaded using a three-roll mill to prepare alkaline-developable resin compositions (two-component systems consisting of a main agent composition and a curing agent composition) of Examples 1 to 6 and Comparative Examples 1 to 5, respectively.

[0121] [Table 1]

[0122]

[0123]

[0124] The components described in Table 1 are as follows.

[0125] *1: The same carboxyl vinyl ester resin obtained in Synthesis Example, solid content 65%, solvent 35%

[0126] *2: Black toner: MA100 (carbon black) manufactured by Mitsubishi Chemical Corporation, JY-140P (carbon black) manufactured by Hangzhou Junyi New Materials Technology Co., Ltd.

[0127] *3: Defoaming agent: KS-66, manufactured by Shin-Etsu Chemical Co., Ltd.

[0128] *4: Leveling agent: BYK-1790, manufactured by BYK Additives (Shanghai) Co., Ltd.

[0129] *5: Photopolymerization initiator: ITX, #369E manufactured by Tianjin Jiuri New Materials Co., Ltd.

[0130] *6: Silica, A-8, manufactured by Sibelco

[0131] *7: Barium sulfate: B-30, manufactured by Sakai Chemical Industry Co., Ltd.

[0132] *8: Solvent: DPM: Made by Taiwan Leander Co., Ltd.

[0133] *9: Epoxy resin: N-770-75EA, manufactured by DIC Corporation, novolac type multifunctional epoxy resin, solid content 75%

[0134] *10: Photosensitive monomer: DPHA, dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.

[0135] *11: Melamine: MELAMINE-JC, manufactured by Jiangsu Jinxiang Sairui Chemical Technology Co., Ltd.

[0136] *12: Hydroxyl compound component: TECH-7200, manufactured by Shanghai Tiger Polymer Technology Co., Ltd., pH: 4.0-5.0, hydroxyl-containing polyester compound, acid value: 30 mgKOH / g, number average molecular weight: 2037, weight average molecular weight: 3115

[0137] *13: Hydroxyl compound component: BYK-102, pH: 2.8, manufactured by BYK Japan Co., Ltd.

[0138] *14: Hydroxyl compound component: BYK-220SN, pH: 3.5, manufactured by BYK Japan Co., Ltd.

[0139] *15: Hydroxyl compound component: BYK-174, pH: 6.0, manufactured by BYK Japan Co., Ltd.

[0140] The following tests were performed on the obtained main agent compositions, curing agent compositions and alkali-developable resin compositions obtained by mixing the obtained main agent compositions and curing agent compositions of Examples and Comparative Examples.

[0141] <Drying management range (time from drying to exposure and development)>

[0142] The alkaline developing resin composition described in Table 1 was applied to the entire surface of the copper foil substrate with the pattern formed thereon by screen printing, and dried in a hot air circulation drying oven at 80°C. After the start of drying, the substrate was taken out every 10 minutes from 20 minutes to 70 minutes, and slowly cooled to room temperature. The substrate was developed for 60 seconds using a 1wt% sodium carbonate aqueous solution at 30°C at a spray pressure of 0.2MPa, and the maximum allowable drying time without leaving residue was used as the drying management range.

[0143] ○: The maximum allowable drying time without leaving residue is more than 50 minutes

[0144] ×: The maximum allowable drying time without leaving residue is less than 50 minutes

[0145] <Sensitivity>

[0146] The copper-free substrate was polished with a jet scrubber, washed with water, dried, and coated with the alkaline developing resin composition listed in Table 1 by screen printing, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After drying, the substrate was exposed to light at 300 mJ / cm2 using a step tablet (Kodak No. 2). 2 The film was exposed to an exposure amount of 1 wt % sodium carbonate aqueous solution at 30° C. and developed for 60 seconds at a spray pressure of 0.2 MPa. The number of stages remaining on the step exposure meter was used to evaluate the sensitivity.

[0147] <Resolution>

[0148] The alkaline developing resin composition described in Table 1 was applied to a copper-free substrate (FR4) by screen printing or spraying so that the film thickness after drying was 42±2 μm. After drying (80°C, 30 minutes), a predetermined photomask was placed in close contact with the coating film and exposed (exposure on the masking material was 300 mJ / cm 2 ), and then developed (1 wt% Na2CO3, 30°C, 0.2 MPa, 60 seconds) to prepare a test piece. The thinnest residual line in the test piece was visually confirmed.

[0149] <Pencil hardness>

[0150] The pencil hardness of the resin surface of the substrate A was measured and evaluated in accordance with JIS K 5600-5-4. The evaluation criteria are as follows.

[0151] ◎: Pencil hardness 6H or above

[0152] ○: Pencil hardness 4H or higher and lower than 6H

[0153] △: Pencil hardness is less than 4H

[0154] <Acid resistance>

[0155] The evaluation substrate was immersed in a 10 vol % H 2 SO 4 aqueous solution at room temperature for 20 minutes. This was repeated 5 times in total, and the penetration and dissolution of the coating film were visually confirmed, and further the peeling due to tape peeling was confirmed.

[0156] ○: No change observed

[0157] △: Only slightly changed

[0158] ×: The coating film is bulging or swelling and falling off

[0159] <Metal plating resistance>

[0160] Plating was performed using commercially available chemical nickel plating baths and chemical gold plating baths at 0.5 μm for nickel and 0.03 μm for gold, and the presence or absence of plating penetration was evaluated. The presence or absence of peeling of the resist layer was then evaluated by tape peeling. The judgment criteria were as follows.

[0161] ○: No penetration or peeling is observed

[0162] △: Slight penetration can be seen after plating, and peeling can be seen after stripping

[0163] ×: Peeling after plating

[0164] <Alkali resistance>

[0165] The evaluation substrate was immersed in a 10 vol % NaOH aqueous solution at room temperature for 20 minutes, and the penetration and dissolution of the coating film were visually confirmed, and further, the peeling due to tape peeling was confirmed.

[0166] ○: No change observed

[0167] △: Only slightly changed

[0168] ×: The coating film is bulging or swelling and falling off

[0169] <Solvent resistance>

[0170] The evaluation substrate was immersed in propylene glycol monomethyl ether at room temperature for 30 minutes, and the penetration and dissolution of the coating film were visually confirmed, and further, the peeling due to tape peeling was confirmed.

[0171] ○: No change observed

[0172] △: Only slightly changed

[0173] ×: The coating film is bulging or swelling and falling off

[0174] The results shown in Table 1 show that the alkali-developable resin composition of the present invention has excellent drying control range, sensitivity, and resolution, and the formed cured product has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance.

[0175] On the other hand, the curing agent components of Comparative Examples 1 and 2 contain melamine and do not contain a hydroxyl compound component, and the sensitivity decreases by 1-2 levels, and as the amount of melamine used decreases, the acid resistance and metal plating resistance tend to decrease. The curing agent component of Comparative Example 3 does not contain both melamine and a hydroxyl compound component, and the acid resistance and metal plating resistance are poor. The curing agent components of Comparative Examples 4 to 6 do not contain melamine, contain a hydroxyl compound component whose pH is outside a specific range, and have poor acid resistance and metal plating resistance. Although Comparative Examples 7 and 8 contain a hydroxyl compound component whose pH value is within a specific range, the content is insufficient or excessive, and there is still room for improvement in acid resistance and metal plating resistance (basically the same level as Comparative Examples 1 and 2), and Comparative Example 8 tends to have a reduced pencil hardness.

[0176] In contrast, the alkaline-developable resin composition of each example has excellent drying control range, sensitivity, and resolution by containing a hydroxyl compound component having a pH value within a specific range in a specific content in the main agent, and the cured product has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance. In particular, unexpectedly, the acid resistance and metal plating resistance are further improved compared to the case of using melamine. Therefore, the melamine-free alkaline-developable resin composition of the present invention is particularly suitable for a cured product of a printed circuit board using a photolithography method, such as a solder resist, and an electronic component having the cured product.

Claims

1. A melamine-free alkaline developing resin composition, which is composed of a resin composition of at least a two-component system, characterized in that: The alkaline developing resin composition contains: epoxy resin, carboxyl vinyl ester resin, photopolymerization initiator, photosensitive monomer, inorganic filler and hydroxyl compound component. The carboxyl vinyl ester resin and the inorganic filler are contained in different resin compositions from the epoxy resin and the photosensitive monomer. The pH value of the hydroxyl compound component is 4.0 or more and 5.5 or less, and the hydroxyl compound component comprises a hydroxyl compound having at least one hydroxyl group in the molecule. The content of the hydroxyl group-containing compound component is 1.2 to 7.8 parts by mass based on 100 parts by mass of the carboxyl group-containing vinyl ester resin in terms of solid content.

2. The melamine-free alkaline developing resin composition according to claim 1, characterized in that: The hydroxyl group-containing compound having at least one hydroxyl group in the molecule is at least one or more selected from the group consisting of alcohols, phenols, ethers, esters and polymers.

3. The melamine-free alkaline developing resin composition according to claim 1 or 2, characterized in that: The hydroxyl-containing compound having at least one hydroxyl group in the molecule is a polymer having a hydroxyl group on a side chain and / or at a terminal.

4. The melamine-free alkaline-developable resin composition according to claim 1 or 2, characterized in that: The acid value of the hydroxyl-containing compound component having at least one hydroxyl group in the molecule is 10 to 100 mgKOH / g.

5. The melamine-free alkaline-developable resin composition according to claim 1 or 2, characterized in that: The molecular weight of the hydroxyl-containing compound having at least one hydroxyl group in the molecule is in the range of 500 to 5000 in terms of number average molecular weight.

6. The melamine-free alkaline-developable resin composition according to claim 1 or 2, characterized in that: The carboxyl group-containing vinyl ester resin, the photopolymerization initiator, the inorganic filler and the hydroxyl group-containing compound component are contained in different resin compositions from the epoxy resin and the photosensitive monomer. 7 . A dry film obtained by applying the melamine-free alkaline-developable resin composition according to claim 1 to a carrier film and drying the resulting film.

8. A solidified product, characterized in that: This is obtained by curing the melamine-free alkaline-developable resin composition according to any one of claims 1 to 6.

9. A solidified product, characterized in that: This is obtained by curing the resin layer of the dry film according to claim 7.

10. An electronic component, characterized in that: A cured product according to claim 8 or 9.

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