Alkali-formable resin products that do not contain melamine, dry films, solidified products, and electronic components containing such solidified products.

Abstract

Proposed invention: Alkali-deformable resin compositions free of melamine whose solidified products exhibit excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance and solvent resistance, and excellent drying control range, sensitivity and resolution; dry films; solidified products; and electronic components of such solidified products.This composition includes: epoxy resin, carboxyl-containing vinyl ester resin, photopolymerization initiator, photosensitive monomer, inorganic filler, and hydroxyl-containing compound components. The carboxyl-containing vinyl ester resin and inorganic filler are contained within resin components other than the epoxy resin and corresponding photosensitive monomer. The pH value of the hydroxyl-containing compound component is equal to or greater than 4.0 and equal to or less than 5.5. The hydroxyl-containing compound component includes compounds containing at least one hydroxyl group in the molecule, and the content of the hydroxyl-containing compound component is from 1.2 to 7.8 parts by weight, compared to 100 parts by weight of the carboxyl-containing vinyl ester resin based on solid content.

Description

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

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

[0002] Curable resin compositions are commonly used to form permanent coatings such as solder masks in the manufacture of printed circuit boards. Dry film-type compositions and liquid compositions have been developed as such. Furthermore, to enable miniaturization of electronic components, high-precision design structures, and complex manufacturing methods, curable resin compositions are also expected to be capable of patterning using the principles of photography (photolithography), thereby enabling microfabrication. In recent years, alkaline-developable resins that can be developed in dilute weak alkaline aqueous solutions have become mainstream due to environmental concerns.

[0003] Solder resist (also known as solder resist ink) has long been used as a protective material for printed circuit boards (PCBs). Alkaline-developable photosensitive compositions are currently widely used as solder resists in the actual manufacture of printed circuit boards. The mainstream method for forming solder resist layers using these compositions is contact exposure, which involves applying the solder resist composition to a substrate with a circuit formed thereon, drying it, and then applying a vacuum seal with a photomask for exposure.

[0004] Currently available solder mask inks often 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, melamine in the ink also has many problems. It will volatilize during the soldering process (260°C), and according to the EU REACH regulation (Registration, Evaluation, Authorization and Restriction of Chemicals), melamine is classified as an SVHC (Substances of Very High Concern) environmentally controlled substance.

[0005] Patent Document 1 describes a highly sensitive epoxy solder resist acrylic oligomer containing hydroxyl groups, carboxyl groups, and double bonds, with an acid value and epoxy equivalent within a specific range, improving the sensitivity of solder resist inks. However, the inks produced using this epoxy solder resist acrylic oligomer still use a conventional curing agent.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: CN114262424A

[0009] Summary of the Invention

[0010] Technical Problems to be Solved by the Invention

[0011] Traditionally, solder mask inks have typically contained melamine as a thermosetting agent and antioxidant. However, with increasingly stringent environmental requirements, there is a desire to develop alkaline-developable resin compositions that exhibit excellent drying range, sensitivity, and resolution without the use of melamine. Furthermore, the resulting cured products exhibit excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance.

[0012] 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.

[0013] A further 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-developable solder resist composition, and a printed wiring board having a cured film of a solder resist or the like formed thereon as the cured product.

[0014] Solutions for solving problems

[0015] The present inventors have conducted extensive research and have discovered that the above-mentioned problems can be solved by an alkaline-developable resin composition. The alkaline-developable resin composition comprises at least a two-component 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.

[0016] The carboxyl vinyl ester resin and the inorganic filler are contained in different resin compositions from the epoxy resin and the photosensitive monomer.

[0017] The pH value of the hydroxyl compound component is greater than or equal to 4.0 and less than or equal to 5.5. The hydroxyl compound component includes a hydroxyl compound having at least one hydroxyl group in the molecule. The content of the hydroxyl compound component is 1.2 to 7.8 parts by mass relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin calculated as a solid content.

[0018] 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.

[0019] Furthermore, 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 a polymer having hydroxyl groups in the side chain and / or at the terminal, such as a propylene glycol compound and / or a propylene glycol ether compound.

[0020] 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.

[0021] Furthermore, a more preferred embodiment of the present invention relates to an alkali-developable resin composition, wherein the number average 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.

[0022] Furthermore, a more 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.

[0023] Moreover, another aspect of the present invention relates to a dry film having a resin layer obtained by applying the above-mentioned alkali-developable resin composition on a carrier film and drying the resultant.

[0024] Still another embodiment of the present invention relates to the alkali-developable resin composition, characterized in that the composition is used as a material for a solder resist.

[0025] Still another embodiment of the present invention relates to: a cured product obtained by curing an alkaline-developable resin composition; a cured product obtained by curing a resin layer of a dry film; and an electronic component comprising these cured products.

[0026] Effects of the Invention

[0027] According to the present invention, an alkali-developable resin composition can be provided, the cured product of which has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance, and is also excellent in drying control range, sensitivity, and resolution.

[0028] Furthermore, the present invention can provide a dry film and cured product having excellent properties as described above obtained by using such an alkali-developable resin composition, and an electronic component such as a printed wiring board having a cured film such as a solder resist formed on the cured product. DETAILED DESCRIPTION

[0029] The alkaline-developable resin composition of the present invention is preferably composed of at least a two-component resin composition. For example, a two-component system can be employed, wherein one resin composition serves as a base composition and another resin composition serves as a curing agent composition. In this case, for example, the carboxyl vinyl ester resin and inorganic filler are contained in separate resin compositions from the epoxy resin and photosensitive monomer. Preferably, the base composition comprises at least a carboxyl vinyl ester resin, a photopolymerization initiator, an inorganic filler, and a hydroxyl-containing compound component, while the curing agent composition comprises at least an epoxy resin and a photosensitive monomer.

[0030] 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 be contained directly in separate compositions, and the photosensitive monomer and the photopolymerization initiator be contained directly in separate compositions.

[0031] Hereinafter, each component constituting the alkali-developable resin composition of the present invention will be described.

[0032] epoxy resin

[0033] The epoxy resin functions as a thermosetting component in the alkaline-developable resin composition to form a cured product.

[0034] As such an epoxy resin, a well-known and commonly used multifunctional epoxy resin having at least two epoxy groups in one molecule can be used.

[0035] Epoxy resin can be liquid at room temperature, or solid or even semi-solid.

[0036] 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; trishydroxyphenylmethane 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; copolymerized 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.

[0037] These epoxy resins can be used alone or in combination of two or more.

[0038] The epoxy resins that are solid or semi-solid at room temperature can also be known and commonly used. For example, as epoxy resins that are solid at room temperature, bisphenol A epoxy resin (jER1001 manufactured by Mitsubishi Chemical Corporation), bisphenol F epoxy resin (jER4004P manufactured by Mitsubishi Chemical Corporation), naphthalene epoxy resin (HP-4700 manufactured by DIC Corporation), polyfunctional solid epoxy resin containing a naphthalene skeleton (NC-7000 manufactured by Nippon Kayaku Co., Ltd.), trisphenol epoxy resin (EPPN-502H manufactured by Nippon Kayaku Co., Ltd.), polyfunctional solid epoxy resin containing a dicyclopentadiene skeleton (Epiclon manufactured by DIC Corporation), HP-7200), phosphorus-containing epoxy resin (TX0712 manufactured by Nippon Steel & Sumikin Chemicals Corporation), tris(2,3-epoxypropyl)isocyanurate (TEPIC manufactured by Nissan Chemical Industries, Ltd.); as epoxy resins that are semi-solid at room temperature, bisphenol A type epoxy resin (jER834 manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resin (HP-4032 manufactured by DIC Corporation), etc. can be cited.

[0039] Here, in the present invention, being solid or semi-solid at room temperature means being solid or semi-solid at 15° C. Determination of solid or semi-solid can be made in accordance with Annex 2, "Method for Confirming Liquid State," of the Ministerial Ordinance concerning the Test and Properties of Dangerous Substances (Ministry of Home Affairs Ordinance No. 1 of 1991).

[0040] As the biphenyl-type epoxy resin, a well-known and commonly used multifunctional epoxy resin having a biphenyl skeleton can be used. Examples thereof include multifunctional solid epoxy resins containing a biphenyl skeleton (NC-3000H and NC-3000 manufactured by Nippon Kayaku Co., Ltd.) and biphenyl-type epoxy resins (YX-4000 and YL-6121HA manufactured by Mitsubishi Chemical Corporation).

[0041] 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.

[0042] The content of the epoxy resin described above is preferably approximately 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.

[0043] Carboxyl vinyl ester resin

[0044] As the carboxyl vinyl ester resin used in the present invention, those having ethylenically unsaturated double bonds in the molecule are particularly preferred because they can impart alkali developability, photocurability, and development resistance. Examples include resins starting from epoxy resins, polyurethane resins having a urethane backbone, copolymeric resins having a copolymeric structure of unsaturated carboxylic acids, and resins starting from phenolic compounds. Specific examples of carboxyl vinyl ester resins are shown below.

[0045] (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;

[0046] (2) a carboxyl-containing vinyl ester resin obtained by reacting an unsaturated monocarboxylic acid with a polyfunctional epoxy resin and then reacting it with a polyacid anhydride, and further reacting the resultant carboxyl-containing resin with a compound having one oxirane ring and one or more ethylenically unsaturated groups in the molecule;

[0047] (3) Carboxyl group-containing vinyl ester resins 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 the hydroxyl groups present in the side chains;

[0048] (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;

[0049] (5) Carboxyl group-containing vinyl ester resins obtained by adding cyclic ethers such as ethylene oxide or cyclic carbonates such as propylene carbonate to polyfunctional phenolic compounds such as novolac resins, partially esterifying the resulting hydroxyl groups with (meth)acrylic acid, and reacting the remaining hydroxyl groups with polyacid anhydrides;

[0050] (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 α-methylglycidyl (meth)acrylate, to any of the resins described in (3) to (5).

[0051] Particularly preferred among these examples are cresol novolac type and phenol novolac type carboxyl group-containing vinyl ester resins, namely the carboxyl group-containing vinyl ester resins (3), (4), (5), and (6) described above.

[0052] It should be noted that, in this specification, (meth)acrylate is a term that collectively refers to acrylate, methacrylate, and a mixture thereof, and the same applies to other similar expressions.

[0053] 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 with a dilute alkaline aqueous solution.

[0054] The acid value of the carboxyl group-containing vinyl ester resin is preferably in the range of 40 to 200 mgKOH / g, more preferably in the range of 45 to 120 mgKOH / g. An acid value of less than 40 mgKOH / g makes alkali development difficult, while an acid value exceeding 200 mgKOH / g promotes dissolution of the exposed portion by the developer, resulting in thinner lines than desired. The exposed and unexposed portions may also be dissolved and peeled off indiscriminately by the developer, making it difficult to form a normal resist pattern. This is undesirable.

[0055] The weight-average molecular weight of the carboxyl group-containing vinyl ester resin varies depending on the resin backbone, but is generally preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. A weight-average molecular weight of less than 2,000 may result in poor application to a substrate and poor tackiness (dry to touch) after drying. Furthermore, the moisture resistance of the coating film after exposure may deteriorate, film loss may occur during development, and resolution may be significantly reduced. On the other hand, a weight-average molecular weight exceeding 150,000 may significantly deteriorate developability and reduce storage stability.

[0056] Photopolymerization initiator

[0057] Examples of the photopolymerization initiator include bisacylphosphine oxides such as 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, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; and bis(2,6-dimethoxybenzoyl)phenylphosphine oxide. Phosphine oxides such as phosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, methyl 2,4,6-trimethylbenzoylphenylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, isopropyl pivaloylphenylphosphine oxide, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; hydroxyacetophenones such as 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, and 2-hydroxy-2-methyl-1-phenylpropane-1-one; benzoin, benzyl, and 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'-bisdiethylaminobenzophenone 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-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methylthio)phenyl]- Acetophenones such as 1-[4-(4-morpholinyl)phenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone, etc.; thioxanthones such as 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) and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethanone 1-(O-acetooxime); 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, butyroin, anisoin ethyl ether, azobisisobutyronitrile, and tetramethylthiuram disulfide. Photopolymerization initiators may be used alone or in combination of two or more.

[0058] 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 (based on solid content). When the content is 5 parts by mass or greater, surface curability improves, while when it is 25 parts by mass or less, halation is less likely to occur, resulting in good resolution.

[0059] Photosensitive monomer

[0060] The alkaline-developable resin composition capable of forming a cured product of the present invention may contain a known and commonly used photosensitive monomer. For example, the photosensitive monomer may be 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 upon irradiation with active energy rays (if it contains an ethylenically unsaturated group), thereby curing the alkaline-developable resin composition.

[0061] Preferred photosensitive monomers used in the present invention include, 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, and the like. Diol diacrylates such as diol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, diol diacrylates obtained by adding at least one of ethylene oxide and propylene oxide to neopentyl glycol, caprolactone-modified hydroxypivalate neopentyl glycol diacrylate, bisphenol A EO adduct diacrylate, bisphenol A PO adduct diacrylate, tricyclodecane dimethanol diacrylate, hydrogenated dicyclopentadienyl diacrylate, and cyclohexyl diacrylate. 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 such as 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.

[0062] The content of the photosensitive monomer is preferably 5 to 50 parts by mass, more preferably 10 to 45 parts by mass, and even more preferably 15 to 40 parts by mass, relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin in terms of solid content.

[0063] When the content of the photosensitive monomer is within such a range, the alkali-developable resin composition has sufficient photocurability, patterning during development becomes more favorable, and dryness to touch also becomes favorable.

[0064] Inorganic fillers

[0065] In the present invention, the inorganic filler may be used alone or in combination of two or more.

[0066] The amount of inorganic filler added is preferably in the range of 10 to 100 parts by mass, more preferably 15 to 80 parts by mass, and even more preferably 20 to 60 parts by mass, relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin (based on solid content). When the inorganic filler is added in an amount of 10 parts by mass or greater, a cured film with improved solder heat resistance, insulation reliability, reflectivity, and heat discoloration resistance tends to be obtained. When the inorganic filler is added in an amount of 80 parts by mass or less, an alkaline-developable resin composition with improved degassing properties, resolution, and deep-part curing properties tends to be obtained.

[0067] 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, and aluminum nitride. Among these, the inclusion of at least one of talc, silicon dioxide, and barium sulfate is preferred, as it can suppress the cure shrinkage of the cured product of the alkaline-developable resin composition and improve properties such as adhesion, hardness, and reflectivity.

[0068] From the perspective of improving the mechanical properties, heat resistance, processability, and chemical resistance of the cured product, an inorganic filler is preferably included in the main agent. As the inorganic filler, at least one of silica and barium sulfate is preferred.

[0069] The inorganic fillers may be surface-treated ones, and more preferably, the surfaces thereof are surface-treated to introduce curable reactive groups.

[0070] Here, the term "curable reactive group" refers to a group that undergoes a curing reaction with epoxy resins, carboxyl group-containing vinyl ester resins, etc., and may be a photocurable reactive group or a thermosetting reactive group. Examples of photocurable reactive groups include methacryloyl, acryloyl, vinyl, and styryl groups, while examples of thermosetting reactive groups include epoxy, amino, hydroxyl, carboxyl, isocyanate, imino, oxetanyl, mercapto, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, and oxazoline groups.

[0071] The method for introducing curable reactive groups into the surface of the inorganic filler is not particularly limited, and can be introduced using a known conventional method. 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 without a surface treatment having a curable reactive group, for example, silica-alumina surface treatment, titanate coupling agent treatment, aluminate coupling agent treatment, organically treated inorganic fillers, etc. can be cited.

[0072] 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).

[0073] 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 manufactured by MicrotracBEL Inc. can be cited, and as a measuring device based on a dynamic light scattering method, Nanotrac Wave II UT151 manufactured by MicrotracBEL Inc. can be cited.

[0074] Hydroxyl compound components

[0075] The alkaline-developable resin composition of the present invention achieves the above-mentioned object of the present invention by using a hydroxyl compound component having a specific pH value range in the main component.

[0076] Specifically, through intensive research, the inventors discovered that melamine, with its electron-donating capacity, absorbs free radicals, inhibiting photopolymerization to a certain extent, thereby reducing sensitivity. By replacing melamine with a hydroxyl-containing compound component within a specific pH range, it is possible to slightly reduce acid resistance and metal plating resistance while simultaneously improving sensitivity, while maintaining the same drying control range, resolution, alkali resistance, and solvent resistance. Furthermore, surprisingly, adding a hydroxyl-containing compound component within a specific pH range at a specific content further improved acid resistance and metal plating resistance.

[0077] To achieve the above objectives of the present invention, the pH of the hydroxyl-containing compound component is in the range of 4.0 to 5.5, preferably 4.0 to 5.2, and more preferably 4.0 to 5.0. The pH value is measured in accordance with DIN 19268. Furthermore, the acid value of the hydroxyl-containing compound is in the range of 10 to 100 mgKOH / g, preferably 20 to 80 mgKOH / g, and more preferably 25 to 60 mgKOH / g.

[0078] 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 in the side chains and / or at the 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 a hydroxyl group in the side chain and / or at the end, more preferably a polymer having a hydroxyl group and a carboxyl group in the side chain and / or at the end.

[0079] Without prejudice to 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 groups (preferably having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms), alkoxy groups (preferably having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms), alkenyl groups (preferably having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms), alkynyl groups (preferably having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms), amino groups, halogen atoms, amine groups (N atoms are preferably substituted by alkyl groups having 1 to 8 carbon atoms, more preferably substituted by alkyl groups having 1 to 4 carbon atoms), carboxyl groups, and the like.

[0080] Without affecting the purpose of the present invention, the hydroxyl compound component may also contain other ingredients, such as solvents, etc.

[0081] The content of the hydroxyl compound component in the specific pH range is 1.2 to 7.8 parts by mass, 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 the hydroxyl compound component in the specific pH range within the above-mentioned content range, the alkaline-developable resin composition has excellent drying control range, sensitivity, and resolution, and the cured product has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance. Particularly unexpectedly, the acid resistance and metal plating resistance are further improved compared to when melamine is used.

[0082] To further facilitate 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 even more preferably 1500 to 3000, in terms of number average molecular weight. It is preferably 1000 to 6000, more preferably 2000 to 5000, and even more preferably 3000 to 4000, in terms of weight average molecular weight.

[0083] Examples of commercially available products of the hydroxyl compound component within the specific pH range include TECH-7200 (Shanghai Tiger Polymer Technology Co., Ltd.).

[0084] solvent

[0085] In the present invention, for general purposes, such as preparing the various component systems of the alkali-developable resin composition and adjusting the viscosity thereof, a solvent may be used in at least one component system.

[0086] As the 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 monomethyl ether (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.

[0087] These solvents can be used alone or in combination of two or more.

[0088] The content of the solvent in the main 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.

[0089] Other ingredients

[0090] The alkali-developable resin composition of the present invention may, of course, contain further additives as other components as needed within the scope of the object of the present invention.

[0091] Examples of such components include colorants such as pigments and dyes, thermal polymerization 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, and cellulose resins.

[0092] The base composition and curing agent composition of the alkali-developable resin composition of the present invention can be prepared by mixing and dispersing these components in predetermined amounts, for example, using a three-roll mill.

[0093] dry film

[0094] A dry film can be produced from the alkali-developable resin composition of the present invention.

[0095] The dry film of the present invention comprises a resin layer obtained by coating the alkaline-developable resin composition of the present invention on a carrier film and drying the resin layer. To form the dry film, first, in the case of a two-component system, the base composition and the curing agent composition are thoroughly mixed to obtain the alkaline-developable resin composition of the present invention. The composition is then diluted to an appropriate viscosity, either directly or as needed, with a high-boiling-point solvent. The composition is then applied to a uniform thickness on the carrier film using a comma coater, knife coater, lip coater, rod coater, extrusion coater, reverse coater, transfer roll coater, gravure coater, spray coater, or the like. The applied composition is then dried, typically at a temperature of 50 to 130°C for 1 to 30 minutes, to form the resin layer. The coating film thickness is not particularly limited, but is generally selected within the range of 10 to 150 μm, preferably 20 to 60 μm, based on the dried film thickness.

[0096] 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, but is generally selected within the range of 10 to 150 μm.

[0097] After forming a resin layer formed from the alkaline-developable resin composition of the present invention on a carrier film, it is preferable to further laminate a removable cover film on the surface of the resin layer to prevent dust and the like from adhering to the surface of the resin layer. Examples of the removable cover film include polyethylene film, polytetrafluoroethylene film, polypropylene film, and surface-treated paper. The cover film may be any film as long as it is smaller than the adhesion between the resin layer and the carrier film when the cover film is peeled off.

[0098] It should be noted that in the present invention, the alkaline-developable resin composition of the present invention may be applied to the aforementioned cover film and dried to form a resin layer, and a carrier film may be laminated on the surface of the resin layer. In other words, in the present invention, when producing a dry film, either a carrier film or a cover film may be used as the thin film to which the curable composition of the present invention is applied.

[0099] Here, a tack-free resin layer can also be formed by adjusting the alkaline-developable resin composition of the present invention to a viscosity suitable for the coating method using, for example, a high-boiling-point solvent, and applying it to a substrate by dip coating, flow coating, roll coating, bar coating, screen printing, curtain coating, or the like, followed by volatilization and drying of the high-boiling-point solvent contained in the composition at a temperature of approximately 60 to 100° C. (temporary drying). Alternatively, when the composition is applied to a carrier film, dried, and wound as a thin film, the resin layer can be bonded to the substrate using a laminator or the like so that the resin layer of the present invention is in contact with the substrate, and then the carrier film is peeled off to form a resin layer on the surface of the substrate.

[0100] As the above-mentioned substrate, in addition to printed circuit boards and flexible printed circuit boards with circuits pre-formed from copper or the like, there can also be mentioned: 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 ester, etc.

[0101] Cured material

[0102] When forming a cured product using the alkaline developing resin composition of the present invention, 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 portion (the portion irradiated with light) is cured. Specifically, by contact or non-contact method, active energy rays are selectively exposed through a photomask having a pattern, or a laser direct exposure machine is used to directly expose the pattern, and an alkaline aqueous solution (for example, a 0.3-3% by mass sodium carbonate aqueous solution) is used to develop the unexposed portion to form an etching resist pattern. The product is further heated to a temperature of about 100-180° C. and thermally cured (post-cured), thereby forming a cured film (cured product) having excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical properties.

[0103] 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 body using a nozzle).

[0104] In addition, as an exposure machine used in the above-mentioned active energy ray irradiation, any device that is equipped with a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc. and irradiates ultraviolet rays in the range of 350 to 450 nm 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.

[0105] Next, in a development step, the resin layer after the exposure step is treated with a developer to remove the unexposed portion of the coating film, thereby forming a pattern film of the alkali-developable resin composition of the present invention.

[0106] Here, as the method used in the development step, an immersion method, a shower method, a spray method, a brush method, etc. can be used. As the developer, a sodium carbonate aqueous solution with a mass concentration of 0.5 to 5% can generally be used. Other alkaline aqueous solutions can also be used, such as alkaline aqueous solutions of potassium hydroxide, sodium hydroxide, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc.

[0107] In this development step, the temperature of the developer is 20 to 40° C. and the development time is within 180 seconds.

[0108] In the development step, the obtained pattern film may be washed with a rinse solution as needed. As the rinse solution, distilled water, methanol, ethanol, isopropyl alcohol, etc. may be used alone or in combination.

[0109] electronic components

[0110] Furthermore, the present invention can provide an electronic component comprising the cured product.

[0111] The alkaline-developable resin composition or dry film of the present invention can be used as protective films for printed circuit boards, semiconductor elements, etc., electrical insulating layers, sealing materials for sealing or embedding electronic components, component embedding layers, adhesive layers for fixing electronic components, etc., and is particularly suitable for high-density wiring requiring low dielectric constant and low dielectric loss tangent, electronic components that process high-frequency signals, and electronic components for vehicles and robots that require high-temperature and long-term reliability.

[0112] 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.

[0113] 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.

[0114] In addition, unless otherwise specified, the "parts" and "%" shown are based on mass.

[0115] Example

[0116] [Synthesis Example: Synthesis of Carboxyl Group-Containing Vinyl Ester Resin]

[0117] Into an autoclave equipped with a thermometer, a nitrogen inlet device that also serves as an alkylene oxide inlet device, and a stirring 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. While stirring, the system was purged with nitrogen and heated to a high temperature. Subsequently, 63.8 parts of propylene oxide was slowly added dropwise at a temperature of 125-132°C and a pressure of 0-4.8 kg / cm 2 The reaction was allowed to proceed for 16 hours. After cooling to room temperature, 1.56 parts of 89% phosphoric acid was added and mixed to the reaction solution to neutralize the potassium hydroxide, yielding 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.). The average amount of propylene oxide added per equivalent of phenolic hydroxyl groups was 1.08 mol.

[0118] Into a reactor equipped with a stirrer, a thermometer, and an air inlet, 293.0 parts of the 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. Air was blown in at a rate of 10 ml / minute, and the mixture was stirred at 110°C for 12 hours. 12.6 parts of water generated by the reaction were distilled off as an azeotropic mixture with toluene. The reaction solution was then cooled to room temperature, neutralized with 35.35 parts of a 15% aqueous sodium hydroxide solution, and then washed with water. The toluene was then replaced with 118.1 parts of diethylene glycol monoethyl ether acetate in an evaporator and removed by distillation to obtain a novolac-type acrylate resin solution.

[0119] 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. Air was blown in at a rate of 10 ml / minute, and 60.8 parts of tetrahydrophthalic anhydride was slowly added while stirring. The mixture was reacted at 95-101°C for 6 hours, cooled, and then removed. This yielded a carboxyl group-containing vinyl ester resin having a solids content of 65% and an acid value of 87.7 mgKOH / g.

[0120] [Examples 1 to 3 and Comparative Examples 1 to 8]

[0121] The components shown in Table 1 were pre-mixed in a blender at various blending amounts and then kneaded using a three-roll mill to prepare alkaline-developable resin compositions (two-component systems consisting of a base composition and a curing agent composition) of Examples 1 to 3 and Comparative Examples 1 to 8, respectively.

[0122] [Table 1]

[0123] The components described in Table 1 are as follows.

[0124] *1: The same carboxyl vinyl ester resin obtained in the synthesis example, solid content 65%, solvent 35%

[0125] *2: Black toner: MA100 (carbon black) manufactured by Mitsubishi Chemical Corporation, JY-140P (carbon black) manufactured by Hangzhou Junyi New Material Technology Co., Ltd.

[0126] *3: Defoaming agent: KS-66, manufactured by Shin-Etsu Chemical Co., Ltd.

[0127] *4: Leveling agent: BYK-1790, manufactured by BYK Additives (Shanghai) Co., Ltd.

[0128] *5: Photopolymerization initiator: ITX, #369E manufactured by Tianjin Jiuri New Materials Co., Ltd.

[0129] *6: Silica, A-8, manufactured by Sibelco

[0130] *7: Barium sulfate: B-30, manufactured by Sakai Chemical Industry Co., Ltd.

[0131] *8: Solvent: DPM: Made by Taiwan Leondell Corporation

[0132] *9: Epoxy resin: N-770-75EA, manufactured by DIC Corporation, a novolac-type multifunctional epoxy resin, solid content 75%

[0133] *10: Photosensitive monomer: DPHA, dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.

[0134] *11: Melamine: MELAMINE-JC, manufactured by Jiangsu Jinxiang Sairui Chemical Technology Co., Ltd.

[0135] *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

[0136] *13: Hydroxyl compound component: BYK-102, pH: 2.8, manufactured by BYK Japan Co., Ltd.

[0137] *14: Hydroxyl compound component: BYK-220SN, pH: 3.5, manufactured by BYK Japan Co., Ltd.

[0138] *15: Hydroxyl compound component: BYK-174, pH: 6.0, manufactured by BYK Japan Co., Ltd.

[0139] The following tests were performed on the obtained base composition, curing agent composition, and alkali-developable resin composition obtained by mixing these in Examples and Comparative Examples.

[0140] <Drying Management Scope (Time from Drying to Exposure and Development)>

[0141] Each alkaline-developable resin composition listed in Table 1 was screen-printed onto the entire surface of a patterned copper foil substrate and dried in a hot air circulation drying oven at 80°C. After drying began, the substrate was removed every 10 minutes from 20 to 70 minutes and slowly cooled to room temperature. The substrate was then developed using a 1 wt% sodium carbonate aqueous solution at 30°C at a spray pressure of 0.2 MPa for 60 seconds. The maximum allowable drying time without residue was used as the drying control range.

[0142] ○: The maximum allowable drying time without leaving residue is more than 50 minutes

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

[0144] Sensitivity

[0145] The copper-free substrate was polished with a jet scrubber, washed with water, and dried. The alkaline-developable resin compositions listed in Table 1 were then applied 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 / cm using a step tablet (Kodak No. 2). 2 The film was exposed to an exposure dose of 1 wt % sodium carbonate aqueous solution at 30° C. and developed at a spray pressure of 0.2 MPa for 60 seconds. The sensitivity was evaluated by the number of steps remaining on the step exposure meter.

[0146] Resolution

[0147] The alkaline-developable resin composition described in Table 1 was applied to a copper-free substrate (FR4) by screen printing or spraying to a film thickness of 42±2 μm after drying. After drying (80°C, 30 minutes), a predetermined photomask was brought into close contact with the film and exposed (exposure dose 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.

[0148] Pencil hardness

[0149] The substrate production process is as follows:

[0150] The alkaline-developable resin compositions of Examples and Comparative Examples were applied to the entire surface of the copper foil laminate by screen printing to a thickness of 20 μm, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, the exposed film was exposed to light at 300 mJ / cm using an exposure device equipped with a high-pressure mercury lamp. 2 Next, the film was developed in a 1 wt % sodium carbonate aqueous solution at a pressure of 0.2 MPa and a liquid temperature of 30° C. for 60 seconds and then cured in a hot air circulation drying oven at 150° C. for 60 minutes to produce an evaluation substrate A having a cured film.

[0151] 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.

[0152] ◎: Pencil hardness 6H or above

[0153] ○: Pencil hardness 4H or higher and lower than 6H

[0154] △: Pencil hardness is less than 4H

[0155] <Acid resistance>

[0156] The substrate production process is as follows:

[0157] The alkaline-developable resin compositions of Examples and Comparative Examples were applied to the entire surface of the copper foil laminate by screen printing to a thickness of 20 μm, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, the exposed film was exposed to light at 300 mJ / cm using an exposure device equipped with a high-pressure mercury lamp. 2 Next, the substrate was developed in a 1 wt % aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30° C. for 60 seconds, and then cured in a hot air circulation drying oven at 150° C. for 60 minutes to produce an evaluation substrate B having a cured film.

[0158] The evaluation substrate B was immersed in a 10 vol % H 2 SO 4 aqueous solution at room temperature for 20 minutes, which was repeated 5 times in total. The impregnation and dissolution of the coating film were visually confirmed, and further, the peeling due to tape peeling was confirmed.

[0159] ○: No change observed

[0160] △: Only slight change

[0161] ×: The coating film is bulging or swelling and falling off

[0162] <Metal plating resistance>

[0163] The substrate production process is as follows:

[0164] The alkaline-developable resin compositions of Examples and Comparative Examples were applied to the entire surface of the copper foil laminate by screen printing to a thickness of 20 μm, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, the exposed film was exposed to light at 300 mJ / cm using an exposure device equipped with a high-pressure mercury lamp. 2 Next, the substrate was developed in a 1 wt % aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30° C. for 60 seconds, and then cured in a hot air circulation drying oven at 150° C. for 60 minutes to produce an evaluation substrate B having a cured film.

[0165] Commercially available electroless nickel and gold plating baths were used to perform plating at 0.5 μm nickel and 0.03 μm gold, and the presence of plating penetration was evaluated. The presence of peeling of the cured film on substrate B was then evaluated by tape peeling. The evaluation criteria were as follows.

[0166] ○: No penetration or peeling is observed

[0167] △: Slight penetration is observed after plating, and peeling is also observed after stripping.

[0168] ×: Peeling occurs after plating

[0169] <Alkali resistance>

[0170] The substrate production process is as follows:

[0171] The alkaline-developable resin compositions of Examples and Comparative Examples were applied to the entire surface of the copper foil laminate by screen printing to a thickness of 20 μm, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, the exposed film was exposed to light at 300 mJ / cm using an exposure device equipped with a high-pressure mercury lamp. 2 Next, the substrate was developed in a 1 wt % aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30° C. for 60 seconds, and then cured in a hot air circulation drying oven at 150° C. for 60 minutes to produce an evaluation substrate B having a cured film.

[0172] The evaluation substrate B 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.

[0173] ○: No change observed

[0174] △: Only slight change

[0175] ×: The coating film is bulging or swelling and falling off

[0176] Solvent resistance

[0177] The substrate production process is as follows:

[0178] The alkaline-developable resin compositions of Examples and Comparative Examples were applied to the entire surface of the copper foil laminate by screen printing to a thickness of 20 μm, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, the exposed film was exposed to light at 300 mJ / cm using an exposure device equipped with a high-pressure mercury lamp. 2 Next, the substrate was developed in a 1 wt % sodium carbonate aqueous solution at a pressure of 0.2 MPa and a liquid temperature of 30° C. for 60 seconds, and then cured in a hot air circulation drying oven at 150° C. for 60 minutes to produce an evaluation substrate B having a cured film.

[0179] The evaluation substrate B 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.

[0180] ○: No change observed

[0181] △: Only slight change

[0182] ×: The coating film is bulging or swelling and falling off

[0183] 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 cured product thereof has excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance.

[0184] On the other hand, the curing agent components of Comparative Examples 1 and 2 contain melamine and do not contain a hydroxyl compound component, resulting in a decrease in sensitivity by 1-2 steps, 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 has poor acid resistance and metal plating resistance. The curing agent components of Comparative Examples 4 to 6 do not contain melamine and contain a hydroxyl compound component with a pH outside the specific range, and have poor acid resistance and metal plating resistance. Although Comparative Examples 7 and 8 contain a hydroxyl compound component with a pH value within the specific range, the content is insufficient or excessive, and the acid resistance and metal plating resistance still have room for improvement (basically the same level as Comparative Examples 1 and 2), and Comparative Example 8 has a tendency to decrease in pencil hardness.

[0185] In contrast, the alkaline-developable resin compositions of the Examples, by including a hydroxyl compound component at a specific content within a specific pH range in the main agent, exhibit excellent drying control range, sensitivity, and resolution, and the cured products exhibit excellent pencil hardness, acid resistance, metal plating resistance, alkali resistance, and solvent resistance. Particularly and unexpectedly, the acid resistance and metal plating resistance are further improved compared to those using melamine. Therefore, the melamine-free alkaline-developable resin compositions of the present invention are particularly suitable for use in cured products for printed circuit boards (PCBs) using photolithography, such as solder resists, and in electronic components containing the cured products.

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-developable 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 comprising a resin layer obtained by applying the melamine-free alkaline-developable resin composition according to claim 1 to a carrier film and drying the coating.

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.