Curable resin composition, dry film, cured product, and electronic component

Abstract

This invention provides curable resin compositions, dry films, cured products, and electronic components that exhibit high photosensitivity, good touch-drying properties, and yield cured products with excellent flexibility, solder heat resistance, and cross-sectional shape. The curable resin composition comprises: (A) a carboxyl-containing resin having a bisphenol F backbone, (B) a photopolymerization initiator, (C) a photosensitive monomer, (D) an epoxy resin, and (E) an inorganic filler. The (B) photopolymerization initiator comprises (B1) an aminoacetophenone-based photopolymerization initiator and (B2) a benzophenone-based photopolymerization initiator. The (C) photosensitive monomer comprises (C1) a di(meth)acrylate having a polypropylene glycol backbone.

Description

Technical Field

[0001] This invention relates to curable resin compositions, dry films, cured products, and electronic components. Background Technology

[0002] Currently, solder resist inks used in some civilian printed circuit boards and most industrial printed circuit boards typically employ alkali-developable solder resist curing resin compositions. These compositions are formed by alkaline development using a dilute alkaline aqueous solution after irradiation with active energy rays (such as ultraviolet rays, electron beams, etc.) and are then fully cured by heat and / or light irradiation. Such alkali-developable solder resist curing resin compositions require high sensitivity to active energy rays.

[0003] Previously, the photosensitivity of curable resin compositions for alkaline-developable solder resists was mainly ensured by using photosensitizers. For example, Patent Document 1 discloses a liquid photosensitive solder resist ink, characterized by being mainly composed of a main agent and a curing agent in a 3:1 mass ratio. The main agent mainly consists of a photosensitive resin, phthalocyanine green, melamine, a photoinitiator, a photosensitizer, a dispersant, tetramethylbenzene, a leveling agent, a divalent ester solvent, and barium sulfate. Furthermore, there have been studies on imparting high photosensitivity by using specific photoinitiators. For example, Patent Document 2 discloses a photosensitive resin composition, characterized by comprising: a photopolymerizable compound, an oxime ester photoinitiator, and an alkali-soluble resin grafted with silane side chains. Patent Document 3 discloses a photosensitive composition containing a modified 9-phenylacridine photoinitiator, comprising a modified 9-phenylacridine derivative photopolymerizable initiator, an adhesive polymer, a photopolymerizable compound, a photoacidifier, and optional other additives.

[0004] However, in the aforementioned prior art, relying solely on photosensitizers and photoinitiators to improve the photosensitivity of curable resin compositions is limited.

[0005] Patent Document 1: CN102417758A

[0006] Patent Document 2: CN114326299A

[0007] Patent Document 3: CN116339074A Summary of the Invention

[0008] The problem the invention aims to solve

[0009] As mentioned above, in the prior art, photosensitizers and photoinitiators are used to ensure the photosensitivity of curable resin compositions for alkaline-developable solder resists, but the improvement in photosensitivity is limited and there is still room for improvement. In addition, the inventors have found that conventional curable resin compositions sometimes have poor touch-drying properties and poor flexibility, solder heat resistance, and cross-sectional shape of the cured product.

[0010] The purpose of this invention is to provide a curable resin composition having high photosensitivity, good touch-drying properties, and yielding a cured product with excellent flexibility, resistance to welding heat, and cross-sectional shape, as well as dry films, cured products, and electronic components using the same.

[0011] Solution for solving the problem

[0012] The inventors conducted in-depth research and, as a result, successfully obtained a curable resin composition that not only has high photosensitivity and good touch-drying properties, but also produces a cured product with excellent flexibility, weld heat resistance, and cross-sectional shape by combining an aminoacetophenone-based photopolymerization initiator and a benzophenone-based photopolymerization initiator in a curable resin composition containing a carboxyl-containing resin with a bisphenol F backbone, and by blending di(meth)acrylate with a polypropylene glycol backbone.

[0013] That is, the present invention is as follows.

[0014] [1] A curable resin composition, characterized in that it comprises:

[0015] (A) Carboxyl-containing resins with a bisphenol F backbone,

[0016] (B) Photopolymerization initiators,

[0017] (C) Photosensitive monomers,

[0018] (D) Epoxy resin, and

[0019] (E) Inorganic fillers,

[0020] The photopolymerization initiator (B) comprises (B1) an aminoacetophenone-based photopolymerization initiator and (B2) a benzophenone-based photopolymerization initiator.

[0021] The (C) photosensitive monomer comprises (C1) a di(meth)acrylate having a polypropylene glycol backbone.

[0022] [2] The curable resin composition according to [1] is characterized in that the (A) carboxyl-containing resin having a bisphenol F backbone comprises:

[0023] (A1) A carboxyl-containing photosensitive resin is formed by reacting bisphenol F type epoxy resin with a carboxylic acid having an olefinically unsaturated group, reacting the resulting hydroxyl group with an acid anhydride, and adding a compound having a glycidyl group and an olefinically unsaturated group to the resulting carboxyl-containing resin; and / or,

[0024] (A2) A carboxyl-containing photosensitive resin is formed by reacting bisphenol F type epoxy resin with a carboxylic acid having an olefinic unsaturated group, and then reacting the resulting hydroxyl group with an acid anhydride.

[0025] [3] The curable resin composition according to [2] is characterized in that, relative to 100 parts by mass of the carboxyl-containing resin having a bisphenol F skeleton in (A), the total content of the carboxyl-containing photosensitive resin formed by reacting the bisphenol F type epoxy resin with a carboxylic acid having an olefinic unsaturated group, reacting the generated hydroxyl group with an acid anhydride, and adding a compound having a glycidyl group and an olefinic unsaturated group to the carboxyl-containing resin formed therefrom, and the carboxyl-containing photosensitive resin formed by reacting the bisphenol F type epoxy resin with a carboxylic acid having an olefinic unsaturated group and reacting the generated hydroxyl group with an acid anhydride, is 30 parts by mass or more, based on the solid content.

[0026] [4] The curable resin composition according to [1] or [2] is characterized in that, relative to 100 parts by weight of the carboxyl-containing resin having a bisphenol F backbone of (A), the total content of the (B1) aminoacetophenone-based photopolymerization initiator and the (B2) benzophenone-based photopolymerization initiator is 2 to 20 parts by weight.

[0027] [5] The curable resin composition according to [1] or [2] is characterized in that the ratio of the content of the (B1) aminoacetophenone photopolymerization initiator to the content of the (B2) benzophenone photopolymerization initiator is 5 to 100:1 by mass.

[0028] [6] The curable resin composition according to [1] or [2] is characterized in that, in the di(meth)acrylate having a polypropylene glycol backbone, the ratio of the total number of repeating units in the polypropylene glycol backbone to the number of (meth)acrylate functional groups is 3 or more and 10 or less.

[0029] [7] The curable resin composition according to [1] or [2] is characterized in that the content of the (C1) component is 5 to 50 parts by weight relative to 100 parts by weight of the carboxyl-containing resin having a bisphenol F backbone of (A).

[0030] [8] A dry film, characterized in that it has a resin layer obtained from any one of the curable resin compositions [1] to [7].

[0031] [9] A cured product, characterized in that it is obtained by curing the resin layer of the curable resin composition described in any one of [1] to [7] or the dry film described in [8].

[0032]

[10] An electronic component, characterized in that it has the cured material described in [9].

[0033] The effects of the invention

[0034] According to the present invention, a curable resin composition that not only has high photosensitivity and good touch-drying properties, but also produces a cured product with excellent flexibility, resistance to welding heat, and cross-sectional shape, as well as dry films, cured products, and electronic components using the same, can be provided. Detailed Implementation

[0035] This invention relates to a curable resin composition, characterized in that it comprises: (A) a carboxyl-containing resin having a bisphenol F backbone, (B) a photopolymerization initiator, (C) a photosensitive monomer, (D) an epoxy resin, and (E) an inorganic filler, wherein the (B) photopolymerization initiator comprises (B1) an aminoacetophenone-based photopolymerization initiator and (B2) a benzophenone-based photopolymerization initiator, and the (C) photosensitive monomer comprises (C1) a di(meth)acrylate having a polypropylene glycol backbone.

[0036] The components of the curable resin composition of the present invention will be described below. It should be noted that (meth)acrylate refers to the term collectively known as acrylate, methacrylate and mixtures thereof, and the same applies to other similar expressions below.

[0037] (A) Carboxyl-containing resin with a bisphenol F backbone

[0038] The composition of the present invention includes (A) a carboxyl-containing resin having a bisphenol F backbone (also referred to simply as "component (A)") as an essential component. Component (A) achieves alkaline developability by containing carboxyl groups; and achieves high photosensitivity, good touch-drying properties, and flexibility of the cured product by having a bisphenol F backbone.

[0039] From the viewpoint of improving photocurability, the aforementioned component (A) preferably also has an olefinic unsaturated bond within the molecule, and the aforementioned component (A) is further preferably composed of any one of the following carboxyl-containing photosensitive resins: (A1) a carboxyl-containing photosensitive resin formed by reacting a bisphenol F type epoxy resin with a carboxylic acid having an olefinic unsaturated group, reacting the generated hydroxyl group with an acid anhydride, and adding a compound having a glycidyl group and an olefinic unsaturated group to the carboxyl-containing resin formed therefrom (also referred to as "(A1) component"); (A2) a carboxyl-containing photosensitive resin formed by reacting a bisphenol F type epoxy resin with a carboxylic acid having an olefinic unsaturated group, and reacting the generated hydroxyl group with an acid anhydride (also referred to as "(A2) component").

[0040] As a carboxylic acid having an olefinic unsaturated group, (meth)acrylic acid and the like are preferably examples.

[0041] Representative examples of the aforementioned acid anhydrides include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnemidylate tetrahydrophthalic anhydride, chlorobenzyl anhydride, methyltetrahydrophthalic anhydride, etc.; aromatic polycarboxylic anhydrides such as trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride; and their associated polycarboxylic anhydride derivatives such as 5-(2,5-dioxotetrahydrofuran)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, etc., with dicarboxylic anhydrides being preferred.

[0042] The aforementioned bisphenol F type epoxy resin is a resin having a bisphenol F backbone and containing epoxy groups, and any known substance can be used. Examples include difunctional bisphenol F type epoxy resins with two epoxy groups in the molecule and polyfunctional bisphenol F type epoxy resins with multiple epoxy groups in the molecule.

[0043] Examples of compounds containing glycidyl and olefinic unsaturated groups include glycidyl acrylate (meth)acrylate, α-methylglycidyl acrylate (meth)acrylate, and other compounds having one glycidyl group and one or more (meth)acryloyl groups in their molecules.

[0044] As component (A1), a carboxyl-containing photosensitive resin is further preferably formed by adding compounds such as glycidyl methacrylate or α-methylglycidyl methacrylate, which have one glycidyl group and one or more (meth)acryloyl groups in their molecules, to the resins described in (1) to (2) below. As component (A2), the resins described in (1) to (2) below are further preferred.

[0045] (1) A carboxyl-containing photosensitive resin is obtained by reacting bisphenol F type epoxy resin with (meth)acrylic acid to add hydroxyl groups present in the side chain to dicarboxylic acid anhydride.

[0046] (2) A multifunctional epoxy resin obtained by further epoxidizing the hydroxyl groups of bisphenol F type epoxy resin with epichlorohydrin is reacted with (meth)acrylic acid to add dicarboxylic acid anhydride to the generated hydroxyl groups to obtain a carboxyl-containing photosensitive resin.

[0047] (A) The carboxyl-containing resin may also be used in combination with one or more carboxyl-containing resins other than components (A1) and (A2) described above (hereinafter also referred to as "other carboxyl-containing resins"), without impairing the effects of the present invention. Examples of other carboxyl-containing resins include cresol phenolic resin and bisphenol A resin. From the viewpoint of further achieving high photosensitivity, good touch-drying properties, and flexibility of the cured product, the total content of components (A1) and (A2) is preferably 30 parts by mass or more, more preferably 60 parts by mass or more, further preferably 80 parts by mass or more, and particularly preferably 95 parts by mass or more, relative to 100 parts by mass of component (A) based on solids.

[0048] (A) The amount of carboxyl-containing resin in the curable resin composition is preferably 20-80% by weight, based on the solids content. When it is 20% by weight or more and 80% by weight or less, the film strength is good, and the composition exhibits excellent properties such as reduced tackiness and coatability. More preferably, it is 20-60% by weight.

[0049] (B) Photopolymerization initiator

[0050] The photopolymerization initiator (B) contained in the composition of this invention must include (B1) an aminoacetophenone-based photopolymerization initiator (also referred to as "(B1) component") and (B2) a benzophenone-based photopolymerization initiator (also referred to as "(B2) component"). Photopolymerization initiators are classified into intramolecular cleavage type and hydrogen abstraction type. Intramolecular cleavage type photopolymerization initiators absorb light of a specific wavelength, thereby breaking bonds at a specific location and generating free radicals at the cleaved sites, which become polymerization initiators, initiating the polymerization of free radical polymerizable compounds. On the other hand, in the case of hydrogen abstraction type, the photopolymerization initiator absorbs light of a specific wavelength and becomes excited, and this excited species undergoes a hydrogen abstraction reaction from surrounding hydrogen donors, thereby generating active free radicals, which become polymerization initiators, initiating the polymerization of free radical polymerizable compounds. (B1) aminoacetophenone-based photopolymerization initiator is an intramolecular cleavage type photopolymerization initiator, and (B2) benzophenone-based photopolymerization initiator is a hydrogen abstraction type photopolymerization initiator. The inventors have discovered that (B2) benzophenone-based photopolymerization initiator has a low free radical generation efficiency when used alone, but when used in combination with intramolecularly cleaved aminoacetophenone-based photofree radical polymerization initiator, it can improve flexibility and surface hardness, achieving high photosensitivity and good cross-sectional shape.

[0051] Examples of (B1)aminoacetophenone-based photopolymerization initiators include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholino)phenyl]-1-butanone, and N,N-dimethylaminoacetophenone. Commercially available products include Omnirad 907, Omnirad 369, and Omnirad 379 manufactured by IGM RESINS BV.

[0052] Examples of (B2) benzophenone-based photopolymerization initiators include benzophenone, p-methylbenzophenone, Michlein ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bis(diethylamino)benzophenone. Commercially available products include EAB (manufactured by IGM RESINS BV).

[0053] (B) The photopolymerization initiator may also use one or a combination of multiple photopolymerization initiators other than those in (B1) and (B2) above, without impairing the effects of the present invention. As for the photopolymerization initiator other than those in (B1) and (B2) above, there are no particular limitations as long as it is a photopolymerization initiator commonly used in curable resin compositions. Examples include aromatic ketones such as 2-ethylanthraquinone and phenanthraquinone, benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, methyl benzoin, ethyl benzoin, benzoin derivatives such as benzoin dimethyl ketal, 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-chlorophenyl)-4,5-diphenylimidazolium, etc. 2,4,5-triarylimidazolium dimers, including 2-(o-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2,4-di(p-methoxyphenyl)-5-phenylimidazolium dimer, and 2,4-(2,4-dimethoxyphenyl)-4,5-diphenylimidazolium dimer; acridine derivatives such as 9-phenylacridinium and 1,7-bis(9,9'-acridinyl)heptane. Phosphine oxides such as 2,4,6-trimethylbenzoyl diphenylphosphine oxide (TPO), 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide (TMO; (Di-p-tolylphosphoryl)(mesityl)methanone), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, etc.; 1-[9-ethyl Oxime esters such as 1-(O-acetyloxime)-6-(2-methylbenzoyl)-9H-carbazole-3-yl] ethyl ketone (OXE-02), 1-[4-(phenylthio)phenyl]-1,2-octanedione-2-(O-benzoyloxime), and 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyloxime), diaceticopentadiene compounds such as bis(2,6-difluoro-3-pyrrolidinyl)titanium, N-phenylglycine, N-phenylglycine derivatives, and coumarin compounds, etc. These compounds can be used individually or in combination of two or more.

[0054] (B) The amount of photopolymerization initiator mixed with 100 parts by weight of (A) carboxyl-containing resin is preferably 2 to 25 parts by weight, more preferably 2 to 20 parts by weight. With a mixing amount of 2 to 25 parts by weight, a cured film with excellent photosensitivity, flexibility, and chemical resistance can be obtained. In particular, when the mixing amount is 20 parts by weight or less, it is possible to suppress the intense light absorption on the coating surface that would reduce deep curing properties.

[0055] Regarding the total content of components (B1) and (B2), from the viewpoint of further improving photosensitivity, touch dryness, flexibility, and cross-sectional shape, it is preferably 2 to 20 parts by mass, more preferably 3 to 10 parts by mass, relative to 100 parts by mass of component (A) in terms of solid content. Furthermore, from the viewpoint of further improving photosensitivity, touch dryness, flexibility, and cross-sectional shape, the content ratio of component (B1) to component (B2) in terms of mass ratio is preferably 3 to 120:1, more preferably 5 to 100:1.

[0056] (C) Photosensitive monomer

[0057] The (C) photosensitive monomer contained in the composition of the present invention includes (C1) a di(meth)acrylate having a polypropylene glycol backbone (also referred to as the "(C1) component") as an essential component.

[0058] For (C1) di(meth)acrylates having a polypropylene glycol backbone, there are no particular restrictions as long as the compound has a polypropylene glycol backbone and two (meth)acrylate functional groups in the molecule. From the viewpoint of availability, polypropylene glycol di(meth)acrylates are preferred.

[0059] For the di(meth)acrylate having a polypropylene glycol backbone (C1), from the viewpoint of further improving photosensitivity, touch dryness, flexibility, and cross-sectional shape, the ratio of the total number of repeating units in the polypropylene glycol backbone to the number of (meth)acrylate functional groups is preferably 3 or more and 10 or less, more preferably 4 or more and 8 or less. Wherein, in the di(meth)acrylate having a polypropylene glycol backbone (C1), the number of (meth)acrylate functional groups is 2.

[0060] As component (C1), from the viewpoint of further improving photosensitivity, touch dryness, flexibility and cross-sectional shape, polypropylene glycol di(meth)acrylate as shown in formula (1) can preferably be used.

[0061]

[0062] In equation (1), n ​​represents the number of repeating units, preferably 6 or more and 20 or less, and more preferably 8 or more and 16 or less.

[0063] Commercially available products containing (C1) include, for example, APG-400 and APG-700 manufactured by Shin-Nakamura Chemical Industry Co., Ltd.

[0064] (C) The photosensitive monomer may also be used in combination with one or more photosensitive monomers other than the components mentioned above (C1) within the scope that does not impair the effect of the present invention.

[0065] As for photosensitive monomers other than the above-mentioned (C1) component, there are no particular limitations as long as they are photosensitive monomers commonly used in curable resin compositions. Examples include conventionally known polyester (meth)acrylates, polyether (meth)acrylates, urethane (meth)acrylates, carbonate (meth)acrylates, epoxy (meth)acrylates, etc. Specifically, at least one of the following substances may be appropriately selected for use: hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of diols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, propylene glycol, and tricyclodecanediethanol; acrylamides such as N,N-dimethylacrylamide, N-hydroxymethylacrylamide, and N,N-dimethylaminopropylacrylamide; aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate and N,N-dimethylaminopropyl acrylate; polyols such as hexanediol, glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol, and trihydroxyethyl isocyanurate, or their ethylene oxide adducts, ethylene oxide... Polyacrylates such as alkyl adducts or ε-caprolactone adducts; polyacrylates such as phenoxy acrylates, bisphenol A diacrylates and ethylene oxide adducts or propylene oxide adducts of these phenols; polyacrylates such as glycidyl ethers such as glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, and isocyanurate triglycidyl ester; and, not limited to the foregoing, acrylates and melamine acrylates formed by directly acrylate-esterifying polyols such as polyether polyols, polycarbonate diols, hydroxyl-terminated polybutadiene, and polyester polyols, or by acrylate-esterifying polyurethanes with the aid of diisocyanates, as well as various methacrylates corresponding to the aforementioned acrylates. As a photosensitive monomer other than the (C1) component mentioned above, at least one of the following is particularly preferred: a poly(meth)acrylate compound formed by adding caprolactone to dipentaerythritol and further adding (meth)acryloyl; a dipentaerythritol hexaacrylate compound; and a poly(meth)acrylate compound formed by ethoxylating glycerol and further adding (meth)acryloyl. As specific product names, DPCA-60 and DPCA-120 manufactured by Nippon Kayaku Co., Ltd., and A-GLY-20E manufactured by Shin-Nakamura Chemical Industry Co., Ltd. are preferred.

[0066] The amount of component (C) is preferably 5 to 50 parts by weight relative to 100 parts by weight of the carboxyl-containing resin (A) in terms of solids. Regarding the amount of component (C1), from the viewpoint of further improving photosensitivity, touch dryness, flexibility, and cross-sectional shape, the content of component (C1) is preferably 5 to 50 parts by weight, more preferably 8 to 40 parts by weight, and even more preferably 10 to 30 parts by weight relative to 100 parts by weight of component (A) in terms of solids.

[0067] (D) Epoxy resin

[0068] The (D) epoxy resin (also referred to as "(D) component") contained in the composition of the present invention is a resin having epoxy groups, and any known substance may be used within the scope thereof without impairing the effects of the present invention. Examples of (D) components include, for example, a difunctional epoxy resin having two epoxy groups in its molecule, and a polyfunctional epoxy resin having multiple epoxy groups in its molecule.

[0069] Specific examples of component (D) include: jER828, jER834, jER1001, jER1004 manufactured by Mitsubishi Chemical Corporation; EPICLON840, EPICLON850, EPICLON1050, EPICLON2055 manufactured by DIC Corporation; EpotohtoYD-011, YD-013, YD-127, YD-128 manufactured by NIPPON STEEL Chemical & Material Co., Ltd.; DER317, DER331, DER661, DER664 manufactured by Dow Chemical Company; and SUMI-EPOXY manufactured by Sumitomo Chemical Co., Ltd. Bisphenol A type epoxy resins such as ESA-011, ESA-014, ELA-115, ELA-128, and AER330, AER331, AER661, and AER664 manufactured by Asahi Kasei Corporation (all trade names); brominated epoxy resins such as jERYL903 manufactured by Mitsubishi Chemical Corporation, EPICLON152 and EPICLON165 manufactured by DIC Corporation, EpotohtoYDB-400 and YDB-500 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., DER542 manufactured by Dow Chemical Company, SUMI-EPOXY ESB-400 and ESB-700 manufactured by Sumitomo Chemical Co., Ltd., and AER711 and AER714 manufactured by Asahi Kasei Corporation (all trade names); Mitsubishi Chemical jER152, jER154 manufactured by Corporation, DEN431, DEN438 manufactured by Dow Chemical Company, EPICLONN-730, EPICLONN-770, EPICLONN-865 manufactured by DIC Co., Ltd., Epotohto manufactured by NIPPON STEEL Chemical & Material Co., Ltd. YDCN-701, YDCN-704, EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306 made by Nippon Kayaku Co., Ltd., SUMI-EPOXY ESCN-195X, ESCN-220 made by Sumitomo Chemical Co., Ltd., AER made by Asahi Kasei Co., Ltd.ECN-235, ECN-299, etc. (all trade names) are phenolic varnish-type epoxy resins; EPICLON830 manufactured by DIC Corporation, jER807 manufactured by Mitsubishi Chemical Corporation, and Epotohto YDF-170, YDF-175, YDF-2004, etc. (all trade names) are bisphenol F type epoxy resins manufactured by NIPPON STEEL Chemical & Material Co., Ltd.; Epotohto ST-2004, ST-2007, ST-3000 (trade names) and other hydrogenated bisphenol A type epoxy resins manufactured by NIPPON STEEL Chemical & Material Co., Ltd.; jER604 manufactured by Mitsubishi Chemical Corporation and Epotohto manufactured by NIPPON STEEL Chemical & Material Co., Ltd. YH-434, SUMI-EPOXYELM-120 (all trade names) glycidylamine type epoxy resins manufactured by Sumitomo Chemical Co., Ltd.; CELLOXIDE 2021P (all trade names) alicyclic epoxy resins manufactured by Daicel Co., Ltd.; YL-933 (manufactured by Mitsubishi Chemical Corporation), TEN, EPPN-501, EPPN-502 (all trade names) trihydroxyphenylmethane type epoxy resins manufactured by Dow Chemical Company; Mitsubishi Chemical The following are epoxy resins manufactured by the company: YL-6056, YX-4000, YL-6121 (all trade names), etc., of the bixylenol or biphenol type, or mixtures thereof; EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by ADEKA Co., Ltd., EXA-1514 (trade name) manufactured by DIC Co., Ltd., etc., of the bisphenol S type epoxy resin; jER157S (trade name) manufactured by Mitsubishi Chemical Corporation, etc., of the bisphenol A phenolic varnish type epoxy resin; jERYL-931 (trade name) manufactured by Mitsubishi Chemical Corporation, etc., of the tetrahydroxyphenyl ethane type epoxy resin; TEPIC (all trade names) manufactured by Nissan Chemical Co., Ltd., etc., of the heterocyclic epoxy resin; Blemmer DDT (phthalic acid diglycidyl ester) resin manufactured by Nippon Yushi Co., Ltd.; NIPPON STEEL Chemical & Material Co., Ltd.The company manufactures tetraglycidyl dimethyl ethane resins such as ZX-1063; naphthyl-containing epoxy resins such as ESN-190 and ESN-360 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., and HP-4032, EXA-4750, and EXA-4700 (all trade names) manufactured by DIC Co., Ltd.; epoxy resins with a dicyclopentadiene backbone such as HP-7200 and HP-7200H (both trade names) manufactured by DIC; methacrylate glycidyl ester copolymer epoxy resins such as CP-50S and CP-50M manufactured by Nippon Yushi Co., Ltd.; further copolymer epoxy resins of cyclohexyl maleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivatives (such as Epolide PB-3600 manufactured by Daicel Co., Ltd.); and CTBN-modified epoxy resins (such as NIPPONSTEEL Chemical & Material Co., Ltd.). (e.g., YR-102, YR-450 manufactured by Co., Ltd.), but not limited to these. These epoxy resins can be used in one or a combination of two or more. Among them, as component (D), it is preferable to include at least one of bisphenol F type epoxy resin and biphenyl type epoxy resin, more preferably including both bisphenol F type epoxy resin and biphenyl type epoxy resin.

[0070] The amount of component (D) in the mixture is preferably 5 to 85 parts by mass of component (A) relative to 100 parts by mass of solid components, more preferably 10 to 55 parts by mass of solid components.

[0071] (E) Inorganic packing

[0072] In addition to components (A) to (D) mentioned above, this invention also includes inorganic filler (E). By adding inorganic filler (E), the water absorption rate of the cured product can be reduced, and the coefficient of thermal expansion can be lowered. As inorganic filler (E), any known substance can be used without impairing the effects of this invention; examples include talc, titanium dioxide, silicon dioxide, barium sulfate, barium titanate, Neuburg silica, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, and aluminum nitride.

[0073] (E) The amount of inorganic filler mixed is preferably 10 to 100 parts by weight of component (A) relative to 100 parts by weight of solid components, more preferably 20 to 80 parts by weight.

[0074] Other ingredients

[0075] Furthermore, in addition to the components (A) to (E) described above, the present invention may also include a thermosetting catalyst (F). As the thermosetting catalyst (F), any known substance may be used within the scope that does not impair the effects of the present invention, including imidazole derivatives such as imidazole, 2-methylimidazolium, 2-ethylimidazolium, 2-ethyl-4-methylimidazolium, 2-phenylimidazolium, 4-phenylimidazolium, 1-cyanoethyl-2-phenylimidazolium, and 1-(2-cyanoethyl)-2-ethyl-4-methylimidazolium; amine compounds such as dicyandiamide, benzyl dimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, and 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipate dihydrazide and sebacic dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition to these, guanidine, methylguanidine, benzoguanidine, melamine, organic salts of melamine as reaction products of melamine and organic acids such as phthalic acid, and triazine derivatives such as 2,4-diamino-6-methacryloyloxyethyl-triazine, 2-vinyl-2,4-diamino-triazine, 2-vinyl-4,6-diamino-triazine isocyanuric acid adduct, and 2,4-diamino-6-methacryloyloxyethyl-triazine isocyanuric acid adduct can also be used.

[0076] (F) The amount of the thermosetting catalyst mixed is preferably 0.2 to 5 parts by weight of component (A) relative to 100 parts by weight of solid components, more preferably 0.8 to 3.5 parts by weight.

[0077] Furthermore, the curable resin composition of the present invention may also contain various additives such as phthalocyanine blue, phthalocyanine green, titanium dioxide, carbon black, and other commonly known dyes, coloring pigments, defoamers, flame retardants, adhesion promoters, or leveling agents, or commonly known polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, and phenothiazine, depending on the desired physical properties.

[0078] Furthermore, the curable resin composition of the present invention may also contain organic solvents used for preparing the composition and adjusting its viscosity. Examples of organic solvents 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, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, naphtha, and solvent naphtha. These organic solvents may be used alone or in combination of two or more.

[0079] The curable resin composition of the present invention, by combining (A) a carboxyl-containing resin having a bisphenol F backbone, (B1) an aminoacetophenone-based photopolymerization initiator and (B2) a benzophenone-based photopolymerization initiator, and (C1) a di(meth)acrylate having a polypropylene glycol backbone, not only exhibits high photosensitivity and good touch-drying properties, but also yields cured products with excellent flexibility, solder heat resistance, cross-sectional shape, acid resistance, alkali resistance, and solvent resistance. Therefore, the curable resin composition of the present invention is preferably used as a solder resist ink in the manufacture of electronic components such as printed circuit boards.

[0080] Another aspect of the present invention provides a dry film having a resin layer obtained from the above-described curable resin composition.

[0081] The dry film of the present invention can be obtained by coating a carrier film (support) and drying it. During dry film formation, the composition of the present invention is diluted with the aforementioned organic solvent to adjust to an appropriate viscosity as needed, and then coated onto the carrier film with a uniform thickness using a comma coater, doctor blade coater, lip coater, bar coater, extrusion coater, reverse coater, transfer roller coater, gravure coater, spray coater, etc. It is typically dried at a temperature of 50–130°C for 1–30 minutes to produce a resin layer as a dried coating film. There are no particular limitations on the thickness of the resin layer; it is typically selected appropriately within the range of 0.1–100 μm, suitably 0.5–50 μm, based on the dried film thickness.

[0082] Plastic films are used as the carrier film, preferably polyester films such as polyethylene terephthalate, polyimide films, polyamide-imide films, polypropylene films, and polystyrene films. There are no particular restrictions on the thickness of the carrier film, and it is usually appropriately selected within the range of 0.1 to 150 μm.

[0083] At this point, after the resin layer is formed on the carrier film, in order to prevent dust or other contaminants from adhering to the surface of the resin layer, it is preferable to further laminate a peelable cover film onto the surface of the resin layer. As the peelable cover film, for example, polyethylene film, polytetrafluoroethylene film, polypropylene film, or surface-treated paper can be used. When peeling off the cover film, the adhesive force between the resin layer and the cover film should be less than the adhesive force between the resin layer and the carrier film.

[0084] Another aspect of the present invention provides a cured product obtained from the above-described curable resin composition.

[0085] The curable resin composition of the present invention is adjusted to a viscosity suitable for the coating method as needed, and then coated onto a printed circuit board, for example, on which circuitry is formed, by methods such as screen printing, curtain coating, spraying, or roller coating. The organic solvent contained in the composition is evaporated and dried at a temperature of, for example, 60–100°C, as needed, thereby forming a non-sticky coating film. Alternatively, a dry resin layer is laminated onto a printed circuit board on which circuitry is formed. Then, the resulting coating film or the aforementioned dry resin layer is selectively exposed using active energy rays through a photomask with a predetermined exposure pattern. The unexposed areas are developed with a developer to form a resist pattern, and then heated to a temperature of, for example, 140–180°C for thermal curing, thereby obtaining a cured product as a resist film with excellent flexibility, solder heat resistance, cross-sectional shape, acid resistance, alkali resistance, and solvent resistance.

[0086] The evaporative drying after coating the composition of the present invention can be carried out by the following methods: using a device with a heat source that utilizes steam heating, such as a hot air circulating drying oven, IR oven, hot plate, or convection oven, to make hot air convect and contact with the support; and using a nozzle to blow the air onto the support.

[0087] As an exposure machine used for reactive energy irradiation, a device equipped with a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, or a mercury short-arc lamp, which irradiates reactive energy rays in the range of 350–450 nm, is acceptable. Alternatively, a direct tracing device (e.g., a direct imaging device that directly irradiates reactive energy rays based on CAD data from a computer to traceive an image) can also be used. As the light source for the direct tracing machine, a light source with reactive energy rays having a maximum wavelength in the range of 350–410 nm is sufficient. The exposure dose used to form the image varies depending on factors such as film thickness, and is typically set to 20–1000 mJ / cm². 2 The preferred value is 20–800 mJ / cm³. 2 Within the range.

[0088] As for the aforementioned developing methods, immersion, rinsing, spraying, brushing, etc. can be used. As for the developing solution, dilute alkaline aqueous solutions of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc. can be used.

[0089] In addition, the present invention provides an electronic component having the above-described cured material. This electronic component is typically a printed circuit board.

[0090] Example

[0091] The following examples and comparative examples illustrate the present invention in detail, but the present invention is not limited to the following examples. It should be noted that, unless otherwise specified, "parts" and "%" are all mass measurements.

[0092] The components shown in Tables 1 and 2 below were mixed according to the mixing ratio (by mass) of the solid components shown therein, thereby obtaining the curable resin compositions of Examples 1-6 and Comparative Examples 1-8.

[0093] Table 1

[0094]

[0095] Table 2

[0096]

[0097] In the table, * indicates that the sample is not dry enough and cannot be properly exposed and developed, so no reading can be taken; ** indicates that no evaluation was conducted because the sample could not be prepared.

[0098] The details of each component in Tables 1 and 2 are as follows.

[0099] Resin 1: o-cresol type acid-modified epoxy acrylate resin (65% solids), C-2000 manufactured by DIC Corporation.

[0100] (A) Resin 2: Bisphenol F type acid modified epoxy acrylate resin (65% solids), ZFR-1401H manufactured by Nippon Kayaku Co., Ltd.

[0101] Resin 3: Bisphenol A type acid-modified epoxy acrylate resin (64% solids), ZAR-1035 manufactured by Nippon Kayaku Co., Ltd.

[0102] Thermal catalyst: Dicyandiamide (DCDA) manufactured by Yangzhou Suntory Chemical Co., Ltd.

[0103] Pigment 1: Phthalocyanine Blue manufactured by DIC Corporation (pigment 15:3)

[0104] Pigment Paste 2: 1,1'-[(6-phenyl-1,3,5-triazine-2,4-diimino]bisanthraquinone, manufactured by Ciba Specialty Chemicals, Pigment Yellow 147

[0105] (B1) JRcure369 (Photoinitiator): 2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, manufactured by Ningxia Wokailong New Material Co., Ltd.

[0106] (B2) EAB (Photoinitiator): 4,4'-bis(diethylamino)benzophenone, manufactured by Ningxia Wokailong New Material Co., Ltd.

[0107] TPO (Photoinitiator): Omnirad TPO manufactured by IGM RESINS BV

[0108] 784 (photoinitiator): Bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrolo-1-yl)-phenyl)titanium, Omnirad 784 manufactured by IGM Resins BV.

[0109] KS-66 (additive): A mixture of dimethyl polysiloxane and silicic acid, Simethicone KS-66 manufactured by Shin-Etsu Silicon Co., Ltd.

[0110] (D)TDF-2001: Bisphenol F type epoxy resin, manufactured by Shandong Shengquan.

[0111] (D)YX-4000: Biphenyl-type epoxy resin, manufactured by Mitsubishi Chemical Corporation; MELAMINEFUNSAI (thermosetting agent): Polycyanate manufactured by Sichuan Jinxiang Sairui Chemical Co., Ltd.

[0112] (E)B-30: Barium sulfate, BARIACE B-30 manufactured by Sakai Chemical Co., Ltd.

[0113] #150 (Organic Solvent): Solvent-based naphtha manufactured by Jiangsu Hualun Chemical Co., Ltd.

[0114] Monomer 1: KAYARAD DPCA-60 manufactured by Nippon Kayaku Co., Ltd.

[0115] (C1) Monomer 2: Polypropylene glycol (#700) diacrylate, n≈12, APG-700 manufactured by Shin-Nakamura Chemical Industry Co., Ltd.

[0116] Monomer 3: Tricyclic [5.2.1.0] 2,6 Decanedimethylaminoacrylate, A-DCP manufactured by Shin-Nakamura Chemical Industry Co., Ltd.

[0117] Monomer 4: Polyethylene glycol #600 diacrylate, n≈14, A-600 manufactured by Shin-Nakamura Chemical Industry Co., Ltd.

[0118] The performance of the curable resin compositions obtained in Examples 1-6 and Comparative Examples 1-8 was evaluated as follows.

[0119] Evaluation methods and benchmarks

[0120] <Sensitivity>

[0121] The curable resin compositions obtained in Examples 1-6 and Comparative Examples 1-8 were screen-printed onto a 35 μm thick copper circuit pattern substrate that had been polished, ground, washed with water, and dried. The substrates were then dried in a hot air circulating drying oven at 80°C for 30 minutes. Then, using an HMW-201KB photomask manufactured by ORCMANUFACTURING CO.,LTD., and separated by a photomask, the cumulative light intensity was measured at 300 mJ / cm². 2 400mJ / cm 2 500mJ / cm 2 Irradiate a sample with ultraviolet light of wavelength 365nm, using a spray pressure of 2kg / cm². 2 The photomask was developed for 60 seconds using a developing solution (sodium carbonate aqueous solution), and then the residual coating level was visually determined and recorded in Tables 1 and 2. An Eastman Kodak staged exposure table No. 2 was used as the photomask.

[0122] It should be noted that, under various light intensities, the higher the grade of the residual coating, the higher the photosensitivity.

[0123] <Elastic Modulus>

[0124] Evaluation of substrate fabrication method: The curable resin compositions of Examples 1-6 and Comparative Examples 1-8 were screen-printed onto a patterned copper foil laminate to achieve a dry film thickness of 20 μm. The substrates were dried at 80°C for 30 minutes and then cooled to room temperature. For this substrate, an exposure apparatus equipped with a high-pressure mercury lamp was used at 300 mJ / cm². 2 The pattern is exposed by the exposure amount, and then a 1 wt% sodium carbonate aqueous solution at 30°C is developed for 60 seconds under a spray pressure of 0.2 MPa. Then it is heated at 150°C for 60 minutes to cure it, thus obtaining an evaluation substrate with a cured coating.

[0125] The cured coating was peeled off the copper foil, and a strip measuring 7 cm in length, 1 cm in width, and 50 μm in thickness was cut and placed on a tensile testing machine (Shimadzu EZ-SX) for tensile testing. The effective test area was 4 cm in length, 1 cm in width, and 50 μm in thickness, and the tensile test was performed at a speed of 1 mm / s.

[0126] It should be noted that the elastic modulus represents the force required to bend a sample; the lower the value, the better the flexibility.

[0127] <Strain>

[0128] Evaluation of substrate fabrication method: The curable resin compositions of Examples 1-6 and Comparative Examples 1-8 were screen-printed onto a patterned copper foil laminate to achieve a dry film thickness of 20 μm. The substrates were dried at 80°C for 30 minutes and then cooled to room temperature. For this substrate, an exposure apparatus equipped with a high-pressure mercury lamp was used at 300 mJ / cm². 2 The pattern is exposed by the exposure amount, and then a 1 wt% sodium carbonate aqueous solution at 30°C is developed for 60 seconds under a spray pressure of 0.2 MPa. Then it is heated at 150°C for 60 minutes to cure it, thus obtaining an evaluation substrate with a cured coating.

[0129] The cured coating was peeled off the copper foil, and a strip measuring 7 cm in length, 1 cm in width, and 50 μm in thickness was cut and placed on a tensile testing machine (Shimadzu EZ-SX) for tensile testing. The effective test area was 4 cm in length, 1 cm in width, and 50 μm in thickness, and the tensile test was performed at a speed of 1 mm / s.

[0130] The measured elongation at break was used as the evaluation result of strain and is recorded in Tables 1 and 2.

[0131] It should be noted that a higher elongation at break indicates better flexibility.

[0132] <Welding heat resistance>

[0133] Evaluation of substrate fabrication method: The curable resin compositions of Examples 1-6 and Comparative Examples 1-8 were screen-printed onto a patterned copper foil laminate to achieve a dry film thickness of 20 μm. The substrates were dried at 80°C for 30 minutes and then cooled to room temperature. For this substrate, an exposure apparatus equipped with a high-pressure mercury lamp was used at 300 mJ / cm². 2 The pattern is exposed through the negative image film, and then a 1 wt% sodium carbonate aqueous solution at 30°C is developed for 60 seconds under a spray pressure of 0.2 MPa. Then it is heated at 150°C for 60 minutes to cure it, thus obtaining an evaluation substrate with a cured coating.

[0134] The evaluation substrate coated with rosin-based flux was immersed in a solder bath pre-set to 260°C for 60 seconds. After washing off the flux with modified alcohol, the bulging and peeling of the cured coating were visually evaluated. The judgment criteria are as follows.

[0135] ○: No swelling or peeling was observed.

[0136] △: Expansion is present, but no peeling was observed.

[0137] ×: Bulging and peeling are present.

[0138] <Touch dryness>

[0139] The peeling of the negative film after exposure in the fabrication method of the evaluation substrate prepared in the above-mentioned <soldering heat resistance> evaluation is evaluated by visual inspection according to the following criteria.

[0140] ○: No adhesive residue after curing.

[0141] △: Slight adhesive marks were observed on the cured film.

[0142] ×: Numerous adhesive marks were observed on the cured film.

[0143] <Acid Resistance>

[0144] The evaluation substrates prepared in the above-mentioned <soldering heat resistance> evaluation were immersed in a 10 vol% H2SO4 aqueous solution at 20°C for 20 minutes. The penetration and dissolution of the cured coating were visually confirmed, and peeling caused by tape peeling was further confirmed. The judgment criteria are as follows.

[0145] OK: No change observed

[0146] NG: The cured coating has bulging or swelling and peeling.

[0147] <Alkali resistance>

[0148] The evaluation substrates prepared in the above-mentioned <soldering heat resistance> evaluation were immersed in a 10 vol% NaOH aqueous solution at 20°C for 20 minutes. The penetration and dissolution of the cured coating were visually confirmed, and the peeling caused by tape peeling was further confirmed. The judgment criteria are as follows.

[0149] OK: No change observed

[0150] NG: The cured coating has bulging or swelling and peeling.

[0151] Solvent resistance

[0152] The evaluation substrates prepared in the above-mentioned <soldering heat resistance> evaluation were immersed in propylene glycol monomethyl ether at 20°C for 20 minutes. The penetration and dissolution of the cured coating were visually confirmed, and peeling caused by tape peeling was further confirmed. The judgment criteria are as follows.

[0153] OK: No change observed

[0154] NG: The cured coating has bulging or swelling and peeling.

[0155] <Cross-sectional shape>

[0156] Method for fabricating substrate for cross-sectional shape evaluation: For a substrate with a circuit pattern of 300μm / 300μm wire / space on a copper-clad laminate with a copper thickness of 35μm, polishing and grinding are performed as a pretreatment, followed by washing and drying to obtain a substrate for cross-sectional shape evaluation.

[0157] The curable resin compositions of Examples 1-6 and Comparative Examples 1-8 were screen-printed onto the pretreated substrates for evaluating cross-sectional shape, and dried in a hot air circulating drying oven at 80°C for 30 minutes. After drying, exposure was performed using a high-pressure mercury lamp exposure apparatus. The exposure pattern used was a pattern with 100 μm lines drawn in the gaps. After exposure, development was performed using a sodium carbonate aqueous solution for 60 seconds to form the pattern, and the cross-sectional shape was evaluated according to the following criteria.

[0158] ○: The cross-sectional shape of the cured coating does not contain halos or undercuts.

[0159] ×: The cross-sectional shape of the cured coating contains a halo or undercut.

[0160] As clearly shown in Tables 1 and 2, Examples 1-6, which contain (A) a carboxyl-containing resin with a bisphenol F backbone, use a combination of (B1) aminoacetophenone-based photopolymerization initiator and (B2) benzophenone-based photopolymerization initiator as photopolymerization initiators, and contain (C1) di(meth)acrylate with a polypropylene glycol backbone as a photosensitive monomer, all achieved excellent results in the evaluation of photosensitivity, curing flexibility, cross-sectional shape, acid resistance, alkali resistance, and solvent resistance. Among them, Examples 1-4, which use only (A) a carboxyl-containing resin with a bisphenol F backbone, achieved excellent results in the evaluation of touch drying, weld heat resistance, and cross-sectional shape. In Example 5, which uses a combination of (A) a carboxyl-containing resin with a bisphenol F backbone and a carboxyl-containing resin with a bisphenol A backbone, the touch drying was acceptable, but slightly inferior to Examples 1-4. On the other hand, Comparative Example 1, which used a carboxyl-containing resin with an o-cresol-type backbone, received a × result in the touch dryness evaluation, could not be read in the photosensitivity evaluation, and could not prepare an evaluation substrate in other performance evaluations such as flexibility. Comparative Example 6, which used only a carboxyl-containing resin with a bisphenol A backbone, was inferior to the examples in photosensitivity, flexibility, and touch dryness. Comparative Example 4, which did not contain a (B1) aminoacetophenone-based photopolymerization initiator, was inferior to the examples in photosensitivity and flexibility (strain). Comparative Example 5, which did not contain a (B2) benzophenone-based photopolymerization initiator, was inferior to the examples in flexibility and cross-sectional shape. Comparative Examples 2, 3, 7, and 8, which did not contain a (C1) di(meth)acrylate with a polypropylene glycol backbone, were inferior to the examples in at least one of the evaluation results for photosensitivity, flexibility, solder heat resistance, touch dryness, cross-sectional shape, acid resistance, alkali resistance, and solvent resistance.

[0161] These results demonstrate that the curable resin composition of the present invention not only has high photosensitivity and good touch-drying properties, but also produces cured products with excellent flexibility, solder heat resistance, cross-sectional shape, acid resistance, alkali resistance, and solvent resistance, making it suitable for use as a solder resist in electronic components.

Claims

1. A curable resin composition, characterized in that, Include: (A) Carboxyl-containing resins with a bisphenol F backbone, (B) Photopolymerization initiators, (C) Photosensitive monomers, (D) Epoxy resin, and (E) Inorganic fillers, The photopolymerization initiator (B) comprises (B1) an aminoacetophenone-based photopolymerization initiator and (B2) a benzophenone-based photopolymerization initiator. The (C) photosensitive monomer comprises (C1) a di(meth)acrylate having a polypropylene glycol backbone.

2. The curable resin composition according to claim 1, characterized in that, The (A) carboxyl-containing resin having a bisphenol F backbone comprises: (A1) A carboxyl-containing photosensitive resin is formed by reacting bisphenol F type epoxy resin with a carboxylic acid having an olefinically unsaturated group, reacting the resulting hydroxyl group with an acid anhydride, and adding a compound having a glycidyl group and an olefinically unsaturated group to the resulting carboxyl-containing resin; and / or, (A2) A carboxyl-containing photosensitive resin is formed by reacting bisphenol F type epoxy resin with a carboxylic acid having an olefinic unsaturated group, and then reacting the resulting hydroxyl group with an acid anhydride.

3. The curable resin composition according to claim 2, characterized in that, The total content of the carboxyl-containing resin having a bisphenol F backbone, as relative to 100 parts by mass of the carboxyl-containing resin having a bisphenol F backbone, in (A1) reacting a bisphenol F type epoxy resin with a carboxylic acid having an olefinic unsaturated group, reacting the resulting hydroxyl group with an acid anhydride, and adding a compound having a glycidyl group and an olefinic unsaturated group to the resulting carboxyl-containing resin, and in (A2) reacting a bisphenol F type epoxy resin with a carboxylic acid having an olefinic unsaturated group, and reacting the resulting hydroxyl group with an acid anhydride, is 30 parts by mass or more, based on the solid content.

4. The curable resin composition according to claim 1 or 2, characterized in that, The total content of the (B1) aminoacetophenone-based photopolymerization initiator and the (B2) benzophenone-based photopolymerization initiator is 2 to 20 parts by mass relative to 100 parts by mass of the carboxyl-containing resin having a bisphenol F backbone based on solid components.

5. The curable resin composition according to claim 1 or 2, characterized in that, The ratio of the content of the (B1) aminoacetophenone-based photopolymerization initiator to the content of the (B2) benzophenone-based photopolymerization initiator is 5 to 100:1 by mass.

6. The curable resin composition according to claim 1 or 2, characterized in that, In the (C1) di(meth)acrylate having a polypropylene glycol backbone, the ratio of the total number of repeating units in the polypropylene glycol backbone to the number of (meth)acrylate functional groups is 3 or more and 10 or less.

7. The curable resin composition according to claim 1 or 2, characterized in that, The content of component (C1) is 5 to 50 parts by weight relative to 100 parts by weight of the carboxyl-containing resin having a bisphenol F backbone in (A) based on solid content.

8. A dry film, characterized in that, It has a resin layer obtained from the curable resin composition according to any one of claims 1 to 7.

9. A cured product, characterized in that, It is obtained by curing the curable resin composition according to any one of claims 1 to 7 or the resin layer of the dry film according to claim 8.

10. An electronic component, characterized in that, It has the cured product as described in claim 9.

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