Alkaline developable resin composition, dry film, cured product, and electronic component having cured product

Abstract

The invention provides an alkaline developing resin composition, a dry film, a cured product and an electronic component with the cured product, wherein the cured product is excellent in appearance, character adhesion, adherence and cracking resistance, low in volatility and excellent in ink performance. The alkaline developing resin composition is composed of a resin composition of at least a two-component system, and the alkaline developing resin composition comprises (A) epoxy resin, (B) carboxyl-containing vinyl ester resin, (C) photopolymerization initiator, (D) photosensitive monomer, (E) inorganic filler and (F) high-boiling-point solvent, the (B) carboxyl-containing vinyl ester resin, the (C) photopolymerization initiator, the (E) inorganic filler, and the (F) high-boiling-point solvent are contained in a different resin composition from the (A) epoxy resin and the (D) photosensitive monomer, and the boiling point of the high-boiling-point solvent is more than 250 DEG C and 280 DEG C or less.

Description

Technical Field

[0001] The present invention relates to an 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 low-volatile 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 development types that can be developed in dilute weak alkaline aqueous solutions have become mainstream.

[0003] Solder resist (also called solder resist ink) has long been used as a protective material for printed circuit boards. Conventional solder resist uses a highly volatile low-boiling point solvent, and defects such as bubbles and pinholes often occur during application. At the same time, due to its high volatility, it also increases the environmental load.

[0004] As the demand for environmental protection continues to increase, for printed circuit boards that use a large amount of chemicals in the manufacturing process, the relevant standards and regulations aimed at reducing volatile organic compounds (VOCs) are becoming increasingly stringent. Volatile organic compounds refer to any organic compound with an initial boiling point less than or equal to 250°C at a standard pressure of 101.3kPa (see GB / T 38608-2020). VOCs can usually be divided into 8 categories: alkanes, aromatic hydrocarbons, olefins, halogenated hydrocarbons, esters, aldehydes, ketones and other compounds. Common VOCs include benzene, toluene, xylene, styrene, trichloroethylene, trichloromethane, trichloroethane, diisocyanates, diisocyanatolyl esters, etc.

[0005] Patent document 1 uses water to replace high boiling point solvents to reduce VOCs emissions. However, its solder mask ink has the disadvantages of poor storage stability (the carboxyl groups of acrylic resins that can participate in the development reaction in the ink are wrapped by water molecules after being hydrophilic, and the water molecules wrap the carboxyl groups and the sodium carbonate developer acid-base reaction weakened, thereby reducing the developability of the ink, and in severe cases, the development is not clean), complex use process, and insufficient ink properties, and limited application range. Patent document 2 uses environmentally friendly solvents (such as ethylene glycol butyl ether (boiling point 171°C), dibasic acid esters (boiling point 196-225°C), diethylene glycol monobutyl ether (boiling point 230.5°C), ethylene glycol acetate (boiling point 83°C), propylene glycol methyl ether (boiling point 120°C) one or more), but the VOCs content is greater than 20%.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent document 1: CN 108219585A

[0009] Patent document 2: CN 113604103A Summary of the invention

[0010] Technical Problems to be Solved by the Invention

[0011] In the past, conventional developing solder resists usually used aromatic solvents (such as heavy aromatic solvent naphtha S-150), and low-boiling ester or ether solvents (such as dipropylene glycol monomethyl ether, diethylene glycol ethyl ether acetate). The main problem is that the volatile organic compound (VOCs) content is greater than 20%, which is relatively harmful to the environment. And because such solvents evaporate quickly, when printing on thick copper plates (for example, copper thickness of 2oz (70μm) or more), or when the printed film thickness is thick, bubbles are easily generated, resulting in orange peel (bumps and wrinkles on the painted surface), pinholes (traces after de-bubbling, like the surface state of being pierced by a needle) and other undesirable conditions in the coating.

[0012] Therefore, it is hoped that under the premise of ensuring the performance of the ink, an alkaline developing resin composition with low volatility (VOCs detection value is less than 10%) and excellent photosensitivity can be prepared. Furthermore, its cured product (paint film) has excellent hardness, and further improves the text adhesion, close adhesion and thermal cycle cracking resistance.

[0013] In addition, from the perspective of ink performance, it is expected to obtain an alkaline-developable resin composition that is less likely to have bubbles when printing thick copper plates, has excellent coating appearance, has better leveling properties, reduces the occurrence of undesirable conditions such as orange peel and pinholes in the paint film, and has better adhesion.

[0014] Therefore, an object of the present invention is to provide an alkali-developable resin composition having excellent coating film dryness to touch, excellent appearance, letter adhesion, adhesion and crack resistance of its cured product, low volatility and excellent ink performance.

[0015] The coating has excellent dryness to touch, and there is no film indentation on the coating surface when exposed. On the contrary, if the dryness to touch is poor, the coating surface is more sticky, and film indentation is easily generated on the coating surface during exposure. After the coating is cured, the surface of the cured coating is also more likely to have indentation marks, and the appearance will deteriorate.

[0016] 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 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.

[0017] Solutions for solving problems

[0018] 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 a resin composition of at least a two-component system, characterized in that the alkaline-developable resin composition contains: (A) an epoxy resin, (B) a carboxyl group-containing vinyl ester resin, (C) a photopolymerization initiator, (D) a photosensitive monomer, (E) an inorganic filler, and (F) a high boiling point solvent.

[0019] The (B) carboxyl group-containing vinyl ester resin, the (C) photopolymerization initiator, the (E) inorganic filler and the (F) high boiling point solvent are contained in different resin compositions from the (A) epoxy resin and the (D) photosensitive monomer.

[0020] The present invention has been completed by the fact that the boiling point of the high boiling point solvent (F) is more than 250°C and less than 280°C.

[0021] Among them, a preferred embodiment of the present invention relates to an alkaline-developable resin composition, characterized in that the (F) high boiling point solvent is at least one or more selected from the group consisting of polyol ethers, polyol esters, organic acid alkyl esters and aliphatic hydrocarbons.

[0022] Furthermore, a preferred embodiment of the present invention relates to an alkaline-developable resin composition, characterized in that the (F) high boiling point solvent is at least one or two or more selected from the group consisting of diethylene glycol dibutyl ether, tripropylene glycol n-butyl ether, tetraethylene glycol dimethyl ether, and tripropylene glycol dibutyl ether.

[0023] Furthermore, a more preferred embodiment of the present invention relates to an alkali-developable resin composition characterized in that the content of the (F) high boiling point solvent is 40 to 80 parts by mass based on 100 parts by mass of the (B) carboxyl group-containing vinyl ester resin in terms of solid content.

[0024] Furthermore, a more preferred embodiment of the present invention relates to an alkali-developable resin composition, wherein at least one component in the at least two-component system further contains a solvent other than the (F) high-boiling-point solvent.

[0025] Furthermore, a more preferred embodiment of the present invention relates to an alkaline-developable resin composition, wherein the content of the volatile organic compound is 10% or less by mass.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] Effects of the Invention

[0030] According to the present invention, it is possible to provide an alkaline-developable resin composition having excellent coating film dryness to touch, excellent appearance, letter adhesion, close adhesion and crack resistance of a cured product obtained by curing the alkaline-developable resin composition, low volatility and excellent photosensitivity and ink performance.

[0031] 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 These are photographs showing cracks in solder resist films used for evaluating thermal shock resistance in Examples.

[0033] Figure 2 This is a photograph showing that the solder resist film used for evaluating thermal shock resistance in Examples was not cracked. DETAILED DESCRIPTION

[0034] 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, it is preferred that the main agent composition is composed of at least (B) a carboxyl group-containing vinyl ester resin, (C) a photopolymerization initiator, (E) an inorganic filler and (F) a high boiling point solvent, and the curing agent composition is composed of at least (A) an epoxy resin and (D) a photosensitive monomer.

[0035] Here, from the viewpoint of preventing chemical reactions during storage, it is preferred that (A) the epoxy resin and (B) the carboxyl group-containing vinyl ester resin are directly contained in different compositions, and (D) the photosensitive monomer and (C) the photopolymerization initiator are directly contained in different compositions.

[0036] In addition, if (B) carboxyl vinyl ester resin and (C) photopolymerization initiator are in the same composition, the detailed mechanism is unclear, but sometimes the composition has poor appearance and coarse particles. The inventors of the present invention have found through research that by using a main agent containing at least (B) carboxyl vinyl ester resin, (C) photopolymerization initiator and (F) high boiling point solvent in a specific boiling point range, this problem can be improved while reducing the VOCs content.

[0037] Hereinafter, each component constituting the alkali-developable resin composition of the present invention will be described.

[0038] (A) Epoxy resin

[0039] (A) The epoxy resin functions as a thermosetting component in the alkaline developing resin composition to form a cured product.

[0040] As such (A) epoxy resin, a known and commonly used multifunctional epoxy resin having at least two epoxy groups in one molecule can be used.

[0041] (A) The epoxy resin may be in a liquid state, a solid state, or even a semi-solid state.

[0042] 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.

[0043] These epoxy resins can be used alone or in combination of two or more.

[0044] The "solid or semi-solid epoxy resin at room temperature" in the component (A) can also use a known 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, 128E manufactured by Nan Ya Plastics Co., Ltd.), 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) can be cited. 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.

[0045] 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).

[0046] As the biphenyl type epoxy resin in the component (A), 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.

[0047] Examples of the novolac epoxy resin in the component (A) 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 bisphenol A novolac epoxy resin (BNE200D75 manufactured by Shanghai Hongze Chemical).

[0048] As the epoxy resin having an isocyanurate ring in the component (A), there can be mentioned isocyanurate triglycidyl epoxy resin (TGIC-G manufactured by Shanghai Xindi Chemical Co., Ltd.) and the like.

[0049] The content of the epoxy resin (A) described above is preferably in the range of about 30 to 90 parts by mass, more preferably 40 to 80 parts by mass, based on 100 parts by mass of the carboxyl group-containing vinyl ester resin (B) in terms of solid content.

[0050] (B) Carboxyl vinyl ester resin

[0051] As the carboxyl group-containing vinyl ester resin (B) used in the present invention, a known resin containing an ethylenically unsaturated double bond in the molecule for imparting alkali developability can be used. From the aspects of photocurability and development resistance, a carboxyl group-containing resin having an ethylenically unsaturated double bond in the molecule is particularly preferred. In addition, it is more preferred that the unsaturated double bond is derived from acrylic acid or methacrylic acid or a derivative thereof. Specific examples of the carboxyl group-containing vinyl ester resin (B) are shown below.

[0052] (1) Vinyl ester resins obtained by copolymerizing unsaturated carboxylic acids such as (meth)acrylic acid with one or more other compounds having unsaturated double bonds;

[0053] (2) Photosensitive vinyl ester resins obtained by adding an ethylenically unsaturated group as a pendant group to a copolymer of an unsaturated carboxylic acid such as (meth)acrylic acid and one or more other compounds having an unsaturated double bond, using a compound having an epoxy group and an unsaturated double bond such as glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, or (meth)acryloyl chloride;

[0054] (3) A photosensitive vinyl ester resin obtained by reacting a copolymer of a compound having an epoxy group and an unsaturated double bond such as glycidyl (meth)acrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate, and another compound having an unsaturated double bond with an unsaturated carboxylic acid such as (meth)acrylic acid, and reacting a polyacid anhydride with the generated secondary hydroxyl group;

[0055] (4) a photosensitive vinyl ester resin obtained by reacting a copolymer of an acid anhydride having an unsaturated double bond such as maleic anhydride and another compound having an unsaturated double bond with a compound having a hydroxyl group and an unsaturated double bond such as 2-hydroxyethyl (meth)acrylate;

[0056] (5) Vinyl ester resins obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a saturated or unsaturated polyacid anhydride with the resulting hydroxyl group;

[0057] (6) A vinyl ester resin containing hydroxyl groups and carboxyl groups obtained by reacting a hydroxyl-containing polymer such as a polyvinyl alcohol derivative with a saturated or unsaturated polybasic acid anhydride, and then reacting a compound having an epoxy group and an unsaturated double bond in one molecule with the resulting carboxylic acid;

[0058] (7) a 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;

[0059] (8) a vinyl ester resin obtained by reacting an unsaturated monocarboxylic acid with a polyfunctional oxetane compound having at least two oxetane rings in one molecule and reacting a saturated or unsaturated polybasic acid anhydride with a primary hydroxyl group in the resulting modified oxetane resin; and

[0060] (9) a 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 group-containing resin, ...;

[0061] (10) A vinyl ester resin obtained by reacting a bifunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a saturated or unsaturated polybasic acid anhydride with the generated hydroxyl group.

[0062] (11) A carboxyl group-containing photosensitive 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;

[0063] (12) a carboxyl group-containing photosensitive resin obtained by reacting a multifunctional epoxy resin obtained by further epoxidizing the hydroxyl groups of the multifunctional epoxy resin in the above-mentioned (11) with (meth)acrylic acid and adding a polybasic acid anhydride to the generated hydroxyl groups;

[0064] (13) A carboxyl-containing photosensitive resin obtained by adding a cyclic ether such as ethylene oxide or a cyclic carbonate such as propylene carbonate to a polyfunctional phenol compound such as a novolac resin, partially esterifying the resulting hydroxyl groups with (meth)acrylic acid, and reacting the remaining hydroxyl groups with a polyacid anhydride;

[0065] (14) A carboxyl group-containing photosensitive resin 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 monomethylglycidyl (meth)acrylate to any of the resins described in (11) to (13);

[0066] Particularly preferred among these examples are cresol novolac type and phenol novolac type, and the carboxyl group-containing vinyl ester resins of (5), (11), (12), (13) and (14) above.

[0067] 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.

[0068] Since the carboxyl group-containing vinyl ester resin (B) 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.

[0069] In addition, the acid value of the carboxyl group-containing vinyl ester resin (B) is preferably in the range of 40 to 200 mgKOH / g, and more preferably in the range of 45 to 120 mgKOH / g. When the acid value of the carboxyl group-containing resin 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 off by the developer without distinction, making it difficult to draw a normal resist pattern, which is not preferred.

[0070] In addition, the weight average molecular weight of the carboxyl group-containing vinyl ester resin (B) varies depending on the resin skeleton, and is generally preferably in the range of 2,000 to 150,000, and more preferably in the range of 5,000 to 100,000. When the weight average molecular weight is less than 2,000, the coating on the substrate and the non-tackiness (dry to touch) after drying may be deteriorated. In addition, 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 150,000, the developability may be significantly deteriorated and the storage stability may be deteriorated.

[0071] (C) Photopolymerization initiator

[0072] (C) The photopolymerization initiator may be, for example, 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 the like; bisacylphosphine oxides such as 2,6-dimethoxybenzoyldiphenylphosphine oxide; Monoacylphosphine oxides such as phenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, methyl 2,4,6-trimethylbenzoylphenylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, isopropyl pivaloylphenylphosphine oxide, 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, 2-hydroxy-2-methyl-1-phenylpropane-1-one; 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- Acetophenones such as 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), 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. ;

[0073] The content of the photopolymerization initiator (C) is preferably 5 to 25 parts by mass based on 100 parts by mass of the carboxyl group-containing vinyl ester resin (B) 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.

[0074] (D) Photosensitive monomer

[0075] 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 (D) photosensitive monomer may be, for example, a compound having one or more ethylenically unsaturated groups in the molecule. Such (D) photosensitive monomer contributes to the photocuring of the (B) carboxyl vinyl ester resin (when containing an ethylenically unsaturated group) based on active energy ray irradiation, thereby curing the alkaline developing resin composition.

[0076] The (D) 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, 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 hydroxypivalic acid neopentyl glycol diacrylate and other diol diacrylates, EO adduct diacrylate of bisphenol A, PO adduct diacrylate of bisphenol A, tricyclodecane dimethanol diacrylate, hydrogenated dicyclopentadienyl diacrylate, cyclohexyl diacrylate ester, or a difunctional (meth)acrylate such as a methacrylate monomer corresponding to them, 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 a polyfunctional acrylate represented by a silsesquioxane-modified product thereof, or a methacrylate monomer corresponding to them, a trifunctional methacrylate, a polyfunctional (meth)acrylate such as ε-caprolactone-modified tris(acryloyloxyethyl)isocyanurate, or a combination of two or more thereof.

[0077] The content of the photosensitive monomer (D) is preferably in the range of 2 to 20 parts by mass, more preferably in the range of 4 to 15 parts by mass, based on 100 parts by mass of the carboxyl group-containing vinyl ester resin (B) in terms of solid content.

[0078] When the content of the photosensitive monomer (D) 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.

[0079] (E) Inorganic filler

[0080] In the present invention, the (E) inorganic filler may be used alone or in combination of two or more.

[0081] The amount of the inorganic filler (E) is preferably in the range of 35 to 200 parts by mass, more preferably in the range of 50 to 150 parts by mass, relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin (B) in terms of solid content. When the amount of the inorganic filler (E) is 35 parts by mass or more, a cured film having better resistance to soldering heat, insulation reliability, and heat discoloration resistance tends to be obtained. When the amount of the inorganic filler (E) is 200 parts by mass or less, an alkaline developing resin composition having better degassing properties, resolution, and deep curing properties tends to be obtained.

[0082] (E) Inorganic fillers include, for example, 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, from the perspective of improving mechanical properties, heat resistance, processability, etc., at least one of talc, silicon dioxide, and barium sulfate is preferred. It is preferred that the inorganic filler is included in the main agent. As the inorganic filler, barium sulfate is preferably used, which can suppress the curing shrinkage of the cured product of the alkaline developing type resin composition and improve the properties such as adhesion and hardness.

[0083] (E) The inorganic filler may be a surface-treated one, and more preferably, the surface of the inorganic filler is subjected to a surface treatment capable of introducing a curable reactive group.

[0084] Here, the curable reactive group refers to a group that undergoes a curing reaction with (A) an epoxy resin or the like, or (B) a carboxyl group-containing vinyl ester resin, and may be a photocurable reactive group or a thermosetting reactive group. Examples of the photocurable 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.

[0085] The method for introducing curable reactive groups into the surface of (E) inorganic filler is not particularly limited, and can be introduced 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, such as 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 that have been treated on the surface 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.

[0086] The average particle size (D50) of the (E) 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).

[0087] (E) 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.

[0088] (F) High boiling point solvent

[0089] The alkaline-developable resin composition of the present invention achieves the above-mentioned object of the present invention by using a high-boiling-point solvent having a higher boiling point than conventional solvents in the main agent component.

[0090] In detail, the inventors have found through active research that if a main resin with a low VOCs content is directly used in an alkaline developing resin composition to reduce the VOCs content to less than 20%, the ink viscosity is high and bubbles are easily generated, resulting in poor printing appearance. If the boiling point of the solvent is too high (over 280°C), it is not easy to volatilize, a large amount of residue is left during pre-baking, and the resin layer has poor touch drying properties.

[0091] By using a high boiling point solvent in a specific boiling point range, i.e., above 250-280°C, the alkaline developing resin composition reduces bubbles during printing and improves the appearance defects such as orange peel and pinholes of the coating film. The ink performance of the alkaline developing resin composition is guaranteed, and due to its low volatility, the environmental load is greatly reduced. On this basis, unexpectedly, the adhesion and thermal cycle crack resistance are further improved.

[0092] As such a high boiling point solvent, it can be, for example, any one or two or more selected from polyol ethers, polyol esters, organic acid alkyl esters (esters obtained by the reaction of organic acids and monohydric alcohols), aliphatic hydrocarbons, etc. Among them, polyol ethers and polyol esters are preferred, and polyol ethers are more preferred from the perspective of further facilitating the realization of the object of the present invention. These high boiling point solvents can be used alone or in combination of two or more.

[0093] Specific examples of the high boiling point solvent include diethylene glycol dibutyl ether (boiling point 254° C.), tripropylene glycol n-butyl ether (boiling point 254° C.), tetraethylene glycol dimethyl ether (boiling point 275° C.), and tripropylene glycol dibutyl ether (boiling point 275° C.).

[0094] The content of the high boiling point solvent is 40 to 80 parts by mass, more preferably 45 to 75 parts by mass, further preferably 50 to 70 parts by mass, and most preferably 60 to 70 parts by mass, relative to 100 parts by mass of (B) carboxyl vinyl ester resin in terms of solid content. If the content is too low, the ink performance is poor, and the adhesion of the cured film is low, and the resistance to cracking in hot and cold cycles is also poor. If the content is too high, there may be a tendency for the dryness to touch to deteriorate. By using a high boiling point solvent in the above content range, the alkaline developing resin composition has excellent ink performance while reducing the VOCs content. Bubbles are not easy to appear when printing thick copper plates, and it has better leveling properties. The cured product has an excellent appearance, and further improves adhesion and cracking resistance.

[0095] Other solvents

[0096] In the present invention, for general purposes, such as preparing each component system of the alkali-developable resin composition and adjusting its viscosity, a solvent other than the above-mentioned high boiling point solvent may be used in at least one component system.

[0097] Solvents other than the high boiling point solvent may be conventional organic solvents, 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.

[0098] These conventional organic solvents can be used alone or in combination of two or more.

[0099] The content of the conventional solvent in the main agent composition of the alkaline developing resin composition of the present invention is preferably in the range of 1 to 40 parts by mass, more preferably in the range of 10 to 25 parts by mass, relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin (B) in terms of solid content. The content of the conventional solvent in the curing agent composition of the alkaline developing resin composition of the present invention is preferably in the range of 2 to 35 parts by mass, more preferably in the range of 4 to 25 parts by mass.

[0100] Other Ingredients

[0101] 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.

[0102] Examples of such components include colorants such as pigments and dyes, thermal polymerization inhibitors, thermal curing catalysts, ultraviolet absorbers, plasticizers, flame retardants, antistatic agents, antioxidants, volatile 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.

[0103] Among them, melamine is preferably added. As an antioxidant, it improves the adhesion between the substrate and the cured film of the heat-curable composition by inhibiting the oxidation of the conductor (copper) on the substrate. As a heat-curing catalyst, it promotes the reaction of at least one of the epoxy group and the oxetane group with the carboxyl group. Thus, the acid and alkali resistance, metal plating resistance, adhesion and hardness of the dry film, curing agent, etc. formed by the alkaline developing resin composition can be improved.

[0104] Melamine may be optionally added to at least one of the main agent composition and the curing agent composition of the alkaline developing resin composition of the present invention. From the perspective of further facilitating the above-mentioned effect, it is more preferred to add melamine to the curing agent composition. The amount of melamine blended is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, relative to 100 parts by mass of the carboxyl group-containing vinyl ester resin (B) calculated as solid content.

[0105] 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.

[0106] Dry film

[0107] A dry film can be made from the alkaline developing resin composition of the present invention. The dry film of the present invention has a resin layer, which is obtained by coating the alkaline developing resin composition of the present invention on a carrier film and drying it. 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 alkaline developing resin composition of the present invention is directly or diluted with a high boiling point solvent as needed 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.

[0108] As the carrier film, a plastic film is generally used, for example, polyester films such as polyethylene terephthalate (PET), polyimide films, polyamide-imide films, polypropylene films, polystyrene films, etc. The thickness of the carrier film is not particularly limited, and is generally appropriately selected within the range of 10 to 150 μm.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] Cured material

[0114] 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.

[0115] 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).

[0116] 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.

[0117] 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.

[0118] 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.

[0119] In this development step, the temperature of the developer is 20 to 40° C. and the development time is within 180 seconds.

[0120] 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.

[0121] Electronic components

[0122] The present invention can also provide an electronic component comprising the above-mentioned cured product.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] In addition, unless otherwise specified, "parts" and "%" shown are based on mass.

[0127] Example

[0128] [Synthesis Example: Synthesis of Carboxyl Group-Containing Vinyl Ester Resin]

[0129] 1070 g (5.0 moles of glycidyl groups (total number of aromatic rings): 5.0 moles) of o-cresol novolac epoxy resin (manufactured by DIC Corporation, EPICLONN-695, softening point 95°C, epoxy equivalent 214, average number of functional groups 7.6), 360 g (5.0 moles) of acrylic acid and 1.5 g of hydroquinone were added to 600 g of diethylene glycol dibutyl ether, and stirred to uniformly dissolve. Next, 4.3 g of triphenylphosphine was added, and the mixture was heated to 110°C for reaction for 2 hours, and then the temperature was raised to 120°C for further reaction for 12 hours. 415 g of diethylene glycol dibutyl ether and 456.0 g (3.0 moles) of tetrahydrophthalic anhydride were added to the obtained reaction solution, and the mixture was reacted at 110°C for 4 hours, and then cooled to obtain a carboxyl group-containing vinyl ester resin (varnish). The solid content concentration of the carboxyl vinyl ester resin (varnish) thus obtained is 65% by mass, and the acid value of the solid content is 89 mgKOH / g. In addition, the weight average molecular weight (Mw) of the obtained carboxyl vinyl ester resin is 9000. It should be noted that the weight average molecular weight of the obtained resin is measured by a high performance liquid chromatograph connected to a pump LC-6AD manufactured by Shimadzu Corporation and three columns Shodex (registered trademark) KF-804, KF-803, and KF-802 manufactured by Showa Denko K.K.

[0130] [Examples 1 to 6 and Comparative Examples 1 to 5]

[0131] 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.

[0132] [Table 1]

[0133]

[0134]

[0135] The components described in Table 1 are as follows.

[0136] *1: Carboxyl vinyl ester resin obtained in Synthesis Example, solid content 65%, solvent content (carbitol acetate (normal solvent)) 35%, manufactured by Zhangjiagang DIC Chemical Co., Ltd.

[0137] *2: Carboxyl vinyl ester resin obtained in Synthesis Example (only the solvent component was replaced), solid content 65%, solvent component (diethylene glycol dibutyl ether ((F) high boiling point solvent *20)) 35%, manufactured by Zhangjiagang DIC Chemical Co., Ltd.

[0138] *3: Carboxyl vinyl ester resin obtained in Synthesis Example (only the solvent component was replaced), solid content 65%, solvent component (hexadecyl alcohol ester (high boiling point solvent *21)) 35%, manufactured by Zhangjiagang DIC Chemical Co., Ltd.

[0139] *4: Carboxyl vinyl ester resin obtained by the synthesis example (in which only the solvent component was replaced), solid content 65%, solvent component (butyl diglycol acetate (conventional organic solvent*22)) 35%, manufactured by Zhangjiagang DIC Chemical Co., Ltd.

[0140] *5: Carboxyl vinyl ester resin obtained in Synthesis Example (only the solvent component was replaced), solid content 65%, solvent component (tripropylene glycol n-butyl ether ((F) high boiling point solvent *23)) 35%, manufactured by Zhangjiagang DIC Chemical Co., Ltd.

[0141] *6: Carboxyl vinyl ester resin obtained in Synthesis Example (only the solvent component was replaced), solid content 65%, solvent component (tetraethylene glycol dimethyl ether ((F) high boiling point solvent *24)) 35%, manufactured by Zhangjiagang DIC Chemical Co., Ltd.

[0142] The difference between *1 to *6: The only difference between the 6 resins is the type of solvent. The solvent content is 35% and the solid content is the same, which is 65%.

[0143] *7: Organic bentonite: volatile agent, ORBEN M, manufactured by Shiraishi Calcium (Shanghai) International Trading Co., Ltd.

[0144] *8: Green color paste: Base product of 6Y-501, manufactured by TOYOCOLOR CO., LTD.

[0145] *9: Antioxidant: IRGANOX 1010, manufactured by BASF JAPAN LTD.

[0146] *10: Defoaming agent: KSZ-118, manufactured by Zhejiang Shin-Etsu Fine Chemical Co., Ltd.

[0147] *11: Leveling agent: BYK-1790, manufactured by BYK Additives (Shanghai) Co., Ltd.

[0148] *12: Photopolymerization initiator: ITX, isopropylthioxanthone (manufactured by DKSH JAPAN)

[0149] *13: Photopolymerization initiator: #907: α-aminoacetophenone-based photopolymerization initiator (Omnirad 907 manufactured by IGM Resins) (2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one)

[0150] *14: Filler: HD25, talc, manufactured by Fushi (Shanghai) Trading Co., Ltd.

[0151] *15: Filler: A2, barium sulfate, manufactured by Foshan Anyi Nanomaterials Co., Ltd.

[0152] *16: Defoaming agent: DS-100, manufactured by Foshan Nanhai Datian Chemical Co., Ltd.

[0153] *17: Anti-sagging agent: BYK-R606, manufactured by BYK Additives (Shanghai) Co., Ltd.

[0154] *18: Conventional organic solvent: DPM, dipropylene glycol monomethyl ether, manufactured by Shanghai Hongze Chemical (boiling point 190°C)

[0155] *19: Conventional organic solvent: S-150, heavy aromatic solvent naphtha, manufactured by Shanghai Hongze Chemical (boiling point 180°C)

[0156] *20: (F) High boiling point organic solvent: diethylene glycol dibutyl ether, manufactured by Anhui Lixing New Materials Co., Ltd. (boiling point 254°C)

[0157] *21: High boiling point organic solvent: Hexadecyl alcohol ester, manufactured by Wuhan Qiaofeng Chemical Technology Co., Ltd. (boiling point 281°C)

[0158] *22: Conventional organic solvent: diethylene glycol butyl ether acetate, manufactured by Guangzhou Yintian New Materials Co., Ltd. (boiling point 245°C)

[0159] *23: (F) High boiling point organic solvent: tripropylene glycol n-butyl ether, manufactured by Dow Chemical (Shanghai) Co., Ltd. (boiling point 275°C)

[0160] *24: (F) High boiling point organic solvent: Tetraethylene glycol dimethyl ether, manufactured by Jinan Mingwei Chemical Co., Ltd. (boiling point 275°C)

[0161] *25: Epoxy resin: 128E, manufactured by Nan Ya Plastics, bisphenol A type epoxy resin (solid content 100%)

[0162] *26: Epoxy resin: BNE200D75, bisphenol A novolac epoxy resin, manufactured by Shanghai Hongze Chemical.

[0163] *27: Epoxy resin: N-770-75EA, manufactured by DIC Corporation, novolac type multifunctional epoxy resin, solid content 75%

[0164] *28: Epoxy resin: TGIC-G, manufactured by Shanghai Xindi Chemical Co., Ltd.

[0165] *29: Photosensitive monomer: DPHA, dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.

[0166] *30: Melamine: MELAMINE-JC, manufactured by Shanghai Xindi Chemical Co., Ltd.

[0167] *31: Conventional organic solvent: DPM, dipropylene glycol monoether, manufactured by Shanghai Hongze Chemical Co., Ltd.

[0168] 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.

[0169] <VOCs content>

[0170] According to GB / T 38608-2020, when the expected VOC content (mass fraction) in the ink is greater than 15%, the difference method is used for determination; when the expected VOC content (mass fraction) in the ink is less than or equal to 15%, gas chromatography is used for determination.

[0171] <Air bubbles during printing>

[0172] The alkaline developing resin composition of the above-mentioned embodiment and comparative example is applied by screen printing to a copper-clad laminate having an opening pattern of φ400μm and a spacing of 600μm with a copper thickness of 3oz (105μm). After standing at room temperature for 30 minutes, it is dried at 80°C for 30 minutes in a hot air circulation drying furnace to prepare a degassing evaluation substrate. The degassing evaluation substrate is observed using a 100-fold optical microscope to confirm whether bubbles occur in the resin filled in the opening pattern portion. The number of opening pattern portions where bubbles occur (number of units) is counted, and the bubble incidence rate of the copper opening pattern portion is evaluated. The evaluation criteria are as follows.

[0173] ○: Bubble occurrence rate less than 50%

[0174] △: Bubble generation rate is more than 50%

[0175] Bubble generation rate (%) = (number of cells with bubbles / total 100 cells) × 100%

[0176] <Dryness to touch>

[0177] Each alkaline-developable resin composition of the above-mentioned examples and comparative examples was applied to the entire surface of a copper-clad laminate polished by a polishing roller by screen printing, and dried at 80°C for 30 minutes to prepare a substrate, and the dryness to touch of the coating surface was evaluated.

[0178] ○: No stickiness at all

[0179] △: Slightly sticky

[0180] ×: Sticky

[0181] <Surface wetting tension of coating film (text adhesion)>

[0182] The alkaline developing resin composition of the example and the comparative example was applied to the entire surface of the copper-clad 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, an exposure device equipped with a high-pressure mercury lamp was used to expose the copper-clad laminate at 400 mJ / cm 2 The whole surface was exposed. Then, it was developed in a 1wt% sodium carbonate aqueous solution, a pressure of 0.2MPa, 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 make an evaluation substrate. The surface tension of the ink coating on the substrate was then tested using a standard dyne pen.

[0183] The higher the surface tension value, the better the hydrophilicity, which is more conducive to text adhesion.

[0184] <Adhesion>

[0185] The alkaline developing resin composition of the example and the comparative example was applied to the entire surface of the copper-clad 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, an exposure device equipped with a high-pressure mercury lamp was used to expose the copper-clad laminate at 400 mJ / cm 2 The whole surface was exposed. Then, 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. A UV conveyor oven was used for these substrates at 2000 mJ / cm 2 Expose to ultraviolet light to produce a substrate for adhesion evaluation.

[0186] Use a grid jig to carve 100 1mm squares on the ink coating of the evaluation substrate, and then use a transparent tape (3M, width 24mm, adhesive strength 1.8N / 10mm or more) to perform a peel test once to confirm the peeling rate of the 1mm square.

[0187] ○: No shedding

[0188] △: Shedding is less than or equal to 1%

[0189] ×: Shedding greater than 1%

[0190] <Crack resistance>

[0191] The alkaline developing resin composition of the example and the comparative example was applied to the entire surface of a substrate having a 2 mm copper wire pattern formed thereon by screen printing so as to have a thickness of 40 μm, and dried in a hot air circulation drying oven at 80° C. for 30 minutes. After cooling to room temperature, an exposure device equipped with a high pressure mercury lamp was used to expose the substrate at 400 mJ / cm 2 The pattern was exposed, and then developed in a 1wt% sodium carbonate aqueous solution, a pressure of 0.2MPa, 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. 2 17 thermal cycle crack resistance evaluation substrates with rectangular resist patterns were made by irradiating ultraviolet rays under the conditions of . A number of evaluation substrates made as above were placed in a thermal cycler that cycles the temperature between -40°C and 140°C and set different cycle times to conduct a thermal shock cycle test (TCT test). Then, the appearance at each cycle number was observed, and the maximum cycle number without cracks was recorded (for the presence or absence of cracks, see Figure 1 and Figure 2 ), and its evaluation criteria are as follows.

[0192] ○: No cracks after more than 500 cycles

[0193] ×: Cracks occurred when the number of cycles was less than 500

[0194] From the results shown in Table 1, it can be seen that the alkaline developing resin composition of the present invention has excellent ink performance while reducing the VOCs content. Bubbles are not easy to appear when printing thick copper plates, and it has better leveling properties. The cured product has an excellent appearance, and further improves the adhesion and crack resistance.

[0195] On the other hand, the main agent compositions of Comparative Examples 1 and 2 contain conventional solvents and do not contain high-boiling-point solvents. Therefore, the VOCs content exceeds the standard, and more bubbles are generated during printing. Although the coating surface has excellent dryness to touch, the coating surface wetting tension is small (low text adhesion), the adhesion is low, and the hot and cold cycle cracking resistance is poor. Comparative Example 3 is mainly based on conventional solvents and contains some high-boiling-point solvents. Although the VOCs content is reduced, more bubbles are still generated during printing, the coating surface wetting tension is small (low text adhesion), the adhesion is low, and the hot and cold cycle cracking resistance is poor. In addition, the dryness to touch is also reduced.

[0196] The main agent composition of Comparative Example 4 contains a high boiling point solvent hexadecyl alcohol ester (boiling point 281°C), the VOCs content is significantly reduced, there are fewer bubbles during printing, and the surface wetting tension of the coating is slightly improved, but the dryness to touch is reduced, the adhesion is low, and the resistance to cracking during hot and cold cycles is poor.

[0197] The main agent composition of Comparative Example 5 contains a high-boiling point solvent, diethylene glycol butyl ether acetate (boiling point 245°C), with reduced VOCs content, fewer bubbles during printing, and slightly improved surface wetting tension of the coating, but reduced dryness to touch, low adhesion, and poor resistance to cracking during hot and cold cycles.

[0198] In contrast, the alkaline developing resin composition of each embodiment not only has a significantly lower VOCs content (reaching less than 10%), but also has fewer bubbles during printing, improved wetting tension on the coating surface, excellent dryness to touch, high adhesion of the cured film, and excellent resistance to cracking during hot and cold cycles. It can be seen that the alkaline developing resin composition of the present invention has less environmental harm, better ink properties, and further improved appearance, text adhesion, adhesion, and cracking resistance of the formed cured film, and is particularly suitable for cured products of printed circuit boards using photolithography, such as solder resists, and electronic components having the cured products.

Claims

1. An alkaline developing resin composition, which is composed of at least a two-component system resin composition, characterized in that: The alkaline developing resin composition comprises: (A) an epoxy resin, (B) a carboxyl group-containing vinyl ester resin, (C) a photopolymerization initiator, (D) a photosensitive monomer, (E) an inorganic filler and (F) a high boiling point solvent. The (B) carboxyl group-containing vinyl ester resin, the (C) photopolymerization initiator, the (E) inorganic filler and the (F) high boiling point solvent are contained in different resin compositions from the (A) epoxy resin and the (D) photosensitive monomer. The boiling point of the (F) high boiling point solvent is higher than 250°C and lower than 280°C.

2. The alkaline-developable resin composition according to claim 1, characterized in that: The (F) high boiling point solvent is at least one or two or more selected from the group consisting of polyol ethers, polyol esters, organic acid alkyl esters and aliphatic hydrocarbons.

3. The alkaline-developable resin composition according to claim 1 or 2, characterized in that: The (F) high boiling point solvent is at least one or more selected from the group consisting of diethylene glycol dibutyl ether, tripropylene glycol n-butyl ether, tetraethylene glycol dimethyl ether, and tripropylene glycol dibutyl ether.

4. The alkaline-developable resin composition according to claim 1 or 2, characterized in that: The content of the high boiling point solvent (F) is 40 to 80 parts by mass based on 100 parts by mass of the carboxyl group-containing vinyl ester resin (B) in terms of solid content.

5. The alkaline-developable resin composition according to claim 1 or 2, characterized in that: At least one component of the at least two-component system further comprises a solvent other than the (F) high boiling point solvent.

6. The alkaline-developable resin composition according to claim 1 or 2, characterized in that: The content of volatile organic compounds is less than 10% by mass. 7 . A dry film obtained by applying the alkali-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 alkali-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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