Photosensitive thermosetting resin composition, dry film, cured product, and electronic component having cured product

Abstract

The invention provides a photosensitive thermosetting resin composition, a dry film, a cured product and an electronic component with the cured product, wherein the photosensitive thermosetting resin composition has excellent ink characteristics, and the formed cured film has further improved whitening resistance, heat resistance, cracking resistance, pencil hardness, CTI value and wear resistance. The photosensitive thermosetting resin composition is composed of a resin composition of at least a two-component system, and the photosensitive thermosetting resin composition comprises (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photopolymerization initiator, (D) a photosensitive monomer and (E) polytetrafluoroethylene micro powder, the epoxy resin (B) and the photosensitive monomer (D) are respectively contained in different resin compositions, and the teflon fine powder (E) has a median diameter D50 of 2.5 [mu] m or more and 12 [mu] m or less.

Description

Technical Field

[0001] The present invention relates to a photosensitive thermosetting resin composition, a dry film, a cured product, and an electronic component having the cured product. Background Art

[0002] In the formation of permanent coatings such as solder masks in the manufacture of printed circuit boards (PCBs), solder resist agents (also called solder resist inks) in the form of curable resin compositions are usually used. As such curable resin compositions, dry film-type compositions, liquid compositions, etc. have been developed. In addition, for semiconductor devices used in electrical products, transportation vehicles, etc. under severe conditions such as humidity, high temperature and high pressure, for example, the PCBs of air conditioners, water heaters, washing machines, and charging components of new energy vehicles, etc., since leakage (tracking failure) may occur when there is moisture, dirt, etc. on the material surface, ultimately leading to a short circuit, there is a tendency to use solder resist agents of high-reliability electronic materials as such solder resist agents.

[0003] Conventionally, the CTI (Comparative Tracking Index) value of conventional solder resist agents is low, and due to reasons such as thermal expansion and contraction, the anti-cracking performance under thermal shock is usually poor, and the reliability against environmental changes is poor. In addition, from the perspectives of improving electrical safety performance, protecting copper circuits, and aesthetics, etc., the solder mask must also have excellent hardness and wear resistance.

[0004] Patent Document 1 discloses a friction and scratch resistant ink, in which the filler is mainly talc and / or kaolin, and barium sulfate and cellulose are added, and polytetrafluoroethylene micropowder is not used, and it is speculated that there is still room for improvement in its CTI value and wear resistance. Patent Document 2 discloses a wave-transparent protective composite material, in which the Teflon coating layer is used to protect the substrate layer and the ink layer, and it is not added and used as an ink component.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: CN111117343A

[0008] Patent Document 2: CN116023821A Summary of the Invention

[0009] Technical Problems to be Solved by the Present Invention

[0010] In recent years, due to the development of fields such as smart homes and new energy vehicles, the requirements for the electronic devices used have been continuously increasing. Therefore, it is desired that the solder resist for PCB boards can form a cured film with both a high CTI value and high wear resistance while ensuring excellent ink properties, and at the same time, properties such as whitening resistance, heat resistance, cracking resistance, and pencil hardness are further improved.

[0011] Therefore, the object of the present invention is to provide a photosensitive thermosetting resin composition having excellent ink properties and further improved whitening resistance, heat resistance, cracking resistance, pencil hardness, CTI value, and wear resistance of the formed cured film.

[0012] Furthermore, the 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 a photosensitive thermosetting resin composition, and a printed circuit board formed by forming a cured coating film such as a solder resist from the dry film and the cured product.

[0013] Solutions for solving the problems

[0014] The present inventors have conducted in-depth research and found that the above problems can be solved by the following photosensitive thermosetting resin composition.

[0015] The photosensitive thermosetting resin composition is composed of at least a two-component resin composition, and is characterized in that the photosensitive thermosetting resin composition contains: (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photoinitiator, (D) a photosensitive monomer, and (E) polytetrafluoroethylene fine powder.

[0016] The (A) carboxyl group-containing resin and the (C) photoinitiator are respectively contained in different resin compositions from the (B) epoxy resin and the (D) photosensitive monomer.

[0017] The median particle size D50 of the (E) polytetrafluoroethylene fine powder is 2.5 μm or more and 12 μm or less, and the present invention is completed.

[0018] Among them, a preferred embodiment of the present invention relates to a photosensitive thermosetting resin composition, characterized in that the (A) carboxyl group-containing resin, the (C) photoinitiator, and the (E) polytetrafluoroethylene fine powder are respectively contained in different resin compositions from the (B) epoxy resin and the (D) photosensitive monomer.

[0019] Furthermore, a preferred embodiment of the present invention relates to a photosensitive thermosetting resin composition, characterized in that the median particle size D50 of the (E) polytetrafluoroethylene fine powder is 3 μm or more and 10 μm or less.

[0020] Furthermore, a preferred embodiment of the present invention relates to a photosensitive thermosetting resin composition, characterized in that the content of the (E) polytetrafluoroethylene fine powder is 5% by weight to 20% by weight based on the total weight of the solid components of the photosensitive thermosetting resin composition.

[0021] Furthermore, a more preferred embodiment of the present invention relates to a photosensitive thermosetting resin composition, characterized in that it further contains an (F) inorganic filler, and the (F) inorganic filler is an inorganic filler other than the (E) polytetrafluoroethylene fine powder.

[0022] Furthermore, a further preferred embodiment of the present invention relates to a photosensitive thermosetting resin composition, characterized in that the specific gravity of the (F) inorganic filler is 3.5 or more.

[0023] Furthermore, a further preferred embodiment of the present invention relates to a photosensitive thermosetting resin composition, characterized in that the (F) inorganic filler is barium sulfate.

[0024] In addition, another embodiment of the present invention relates to a dry film obtained by coating the above photosensitive thermosetting resin composition on a carrier film and drying.

[0025] A further additional embodiment of the present invention relates to: a cured product, characterized in that it is obtained by curing the above photosensitive thermosetting resin composition; a cured product, characterized in that it is obtained by curing the resin layer of the above dry film; an electronic component, characterized in that it has the above cured products.

[0026] Effects of the Invention

[0027] According to the present invention, it is possible to provide a photosensitive thermosetting resin composition having excellent ink properties, and further improved whitening resistance, heat resistance, crack resistance, pencil hardness, CTI value, and wear resistance of the formed cured film.

[0028] Furthermore, according to the present invention, it is possible to provide: a dry film and a cured product having the above excellent characteristics obtained by using such a photosensitive thermosetting resin composition, and an electronic component such as a printed circuit board formed by curing a solder resist film or the like with the dry film and the cured product. Brief Description of the Drawings

[0029] Figure 1 It is a photograph showing the cracking (NG) of the solder resist film for evaluating the thermal shock resistance in the examples.

[0030] Figure 2 It is a photograph showing that the solder resist film for evaluating the thermal shock resistance in the examples did not crack (OK). Detailed Description

[0031] The photosensitive thermosetting resin composition of the present invention is preferably composed of at least a two-component resin composition. For example, a two-component system in which one resin composition is used as the main agent composition and another resin composition is used as the curing agent composition can be cited. In this case, for example, it is preferable that the main agent composition is composed of at least (A) a carboxyl group-containing resin and (C) a photopolymerization initiator, and the curing agent composition is composed of at least (B) an epoxy resin and (D) a photosensitive monomer.

[0032] Here, from the viewpoints of preventing chemical reactions during storage and ensuring good dispersibility and printing effect of the resin composition of the present invention, it is preferable that (A) the carboxyl group-containing resin and (B) the epoxy resin are directly included in different compositions from each other, and (D) the photosensitive monomer and (C) the photopolymerization initiator are directly included in different compositions from each other.

[0033] Hereinafter, each component constituting the photosensitive thermosetting resin composition of the present invention will be described.

[0034] (A) Carboxyl-containing resin

[0035] As the (A) carboxyl group-containing resin used in the present invention, a known resin having an ethylenically unsaturated double bond in the molecule for imparting alkali developability can be used. From the viewpoints of photocurability and developability resistance, a carboxyl group-containing resin having an ethylenically unsaturated double bond in the molecule is particularly preferable. Further, it is more preferable that the unsaturated double bond is derived from acrylic acid or methacrylic acid or their derivatives. Specific examples of the (A) carboxyl group-containing resin are shown below.

[0036] (1) A vinyl ester resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid with one or more other compounds having an unsaturated double bond;

[0037] (2) A photosensitive vinyl ester resin obtained by adding an ethylenically unsaturated group in the form of a side 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 or 3,4-epoxycyclohexylmethyl (meth)acrylate, or (meth)acryloyl chloride;

[0038] (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 or 3,4-epoxycyclohexylmethyl (meth)acrylate and one or more other compounds having an unsaturated double bond with an unsaturated carboxylic acid such as (meth)acrylic acid, and reacting a polyanhydride with the resulting secondary hydroxyl group;

[0039] (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 a compound having an unsaturated double bond other than this, with a compound having a hydroxyl group and an unsaturated double bond such as 2-hydroxyethyl (meth)acrylate;

[0040] (5) A vinyl ester resin obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a saturated or unsaturated polybasic acid anhydride with the resulting hydroxyl group;

[0041] (6) A vinyl ester resin containing a hydroxyl group and a carboxyl group, obtained by reacting a hydroxyl group-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;

[0042] (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;

[0043] (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 the primary hydroxyl group in the resulting modified oxetane resin;

[0044] (9) A vinyl ester resin obtained by further reacting a carboxyl group-containing resin obtained by reacting an unsaturated monocarboxylic acid with a polyfunctional epoxy resin and then reacting with a polybasic acid anhydride, with a compound having one oxirane ring and one or more ethylenically unsaturated groups in the molecule;

[0045] (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 resulting hydroxyl group;

[0046] (11) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy resin such as a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, a bisphenol A cresol novolac type epoxy resin, a dicyclopentadiene cresol novolac type epoxy resin, etc. with (meth)acrylic acid, and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, etc. to the hydroxyl group present in the side chain;

[0047] (12) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl group of the polyfunctional epoxy resin in the above (11) with epichlorohydrin, with (meth)acrylic acid, and adding a polybasic acid anhydride to the resulting hydroxyl group;

[0048] (13) A carboxyl group-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 novolac resin, and subjecting the resulting hydroxyl group to partial esterification with (meth)acrylic acid and reacting the remaining hydroxyl group with a polybasic anhydride; and,

[0049] (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 one of the resins in the above (11) to (13).

[0050] Particularly preferred substances among these examples are cresol novolac type and phenol novolac type, which are carboxyl group-containing vinyl ester resins of the above (5), (11), (12), (13), and (14).

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

[0052] The above-mentioned (A) carboxyl group-containing resin can be developed using a dilute aqueous alkali solution because it has a plurality of free carboxyl groups on the side chain of the main-chain polymer.

[0053] In addition, the acid value of the above-mentioned (A) carboxyl group-containing resin is preferably in the range of 40 to 200 mgKOH / g, 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. On the other hand, when it exceeds 200 mgKOH / g, the developer will promote the dissolution of the exposed part, so the line becomes thinner than required, and sometimes the exposed part and the unexposed part are dissolved and peeled off by the developer without distinction, making it difficult to draw a normal resist pattern, so it is not preferred.

[0054] In addition, the weight average molecular weight of the above-mentioned (A) carboxyl group-containing resin varies depending on the resin skeleton, and is usually preferably in the range of 2000 to 150000, more preferably in the range of 5000 to 100000. When the weight average molecular weight is less than 2000, the non-stick property (finger-touch dryness) after coating and drying on the substrate may deteriorate. In addition, the moisture resistance of the coated film after exposure may deteriorate, film reduction may occur during development, and the resolution may deteriorate significantly. On the other hand, when the weight average molecular weight exceeds 150000, the developability may deteriorate significantly and the storage stability may become poor.

[0055] (B) Epoxy resin

[0056] (B) Epoxy resin functions as a thermosetting component in the photosensitive thermosetting resin composition to form a cured product.

[0057] As such (B) epoxy resin, a commonly known and frequently used polyfunctional epoxy resin having at least two epoxy groups in one molecule can be used.

[0058] (B) The epoxy resin can be liquid, or can be solid or semi-solid.

[0059] As the polyfunctional 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; xylenol 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; heterocyclic epoxy resin; diglycidyl phthalate resin; tetraglycidyl xylylene diethanoyl resin; naphthalene group-containing epoxy resin; epoxy resin having a dicyclopentadiene skeleton; glycidyl methacrylate copolymer type epoxy resin; copolymer epoxy resin of cyclohexyl maleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivative; CTBN-modified epoxy resin, epoxy resin having an isocyanurate ring, etc. can be cited, but of course it is not limited to these.

[0060] These epoxy resins can be used singly or in combination of two or more.

[0061] As the "epoxy resin which is solid or semi-solid at normal temperature" in the (B) component, commonly known and frequently used ones can also be used. For example, as the epoxy resin which is solid at normal temperature, bisphenol A type epoxy resin (jER1001 manufactured by Mitsubishi Chemical Corporation, 128E manufactured by Nan Ya Plastics Corporation), bisphenol F type epoxy resin (jER4004P manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resin (HP-4700 manufactured by DIC Corporation), polyfunctional solid epoxy resin containing a naphthalene skeleton (NC-7000 manufactured by Nippon Kayaku Co., Ltd.), triphenol epoxy resin (EPPN-502H manufactured by Nippon Kayaku Co., Ltd.), polyfunctional solid epoxy resin containing a dicyclopentadiene skeleton (Epiclon HP-7200 manufactured by DIC Corporation), 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.) can be cited, and as the epoxy resin which is semi-solid at normal temperature, bisphenol A type epoxy resin (jER834 manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resin (HP-4032 manufactured by DIC Corporation), etc. can be cited.

[0062] Here, in the present invention, being solid or semi-solid at normal temperature means being solid or semi-solid at 15°C. The determination of solid or semi-solid can be carried out in accordance with Appendix 2, "Method for Confirming Liquid State" of the Ordinance on Tests and Properties of Hazardous Substances (Autonomous Province Ordinance No. 1 of 1989).

[0063] As the biphenyl type epoxy resin in component (B), known and commonly used polyfunctional epoxy resins having a biphenyl skeleton can be used. For example, polyfunctional solid epoxy resins containing a biphenyl skeleton (NC-3000H, NC-3000 manufactured by Nippon Kayaku Co., Ltd.), biphenyl type epoxy resins (YX-4000, YL-6121HA manufactured by Mitsubishi Chemical Corporation), etc. can be cited.

[0064] As the novolak type epoxy resin in component (B), cresol novolak type epoxy resin (Epiclon N-690 manufactured by DIC Corporation), phenol novolak type epoxy resin (Epiclon N-770 manufactured by DIC Corporation, jER152 manufactured by Mitsubishi Chemical Corporation), bisphenol A novolak type epoxy resin (BNE200D75 manufactured by Shanghai Hongze Chemical Co., Ltd.), etc. can be cited.

[0065] As the epoxy resin having an isocyanurate ring in component (B), isocyanuric acid triglycidyl ester epoxy resin (TGIC-G manufactured by Shanghai Xindi Chemical Co., Ltd.), etc. can be cited.

[0066] The content of the above-described epoxy resin (B) is preferably in the range of approximately 5 to 90 parts by mass, more preferably in the range of 8 to 80 parts by mass, and still more preferably in the range of 10 to 60 parts by mass, relative to 100 parts by mass of the carboxyl group-containing resin (A) based on solid content.

[0067] (C) Photopolymerization initiator

[0068] As the (C) photoinitiator, examples thereof may include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and other bisacylphosphine oxides; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, methyl 2,4,6-trimethylbenzoylphenylphosphonate, 2-methylbenzoyldiphenylphosphine oxide, isopropyl neopentanoyl phenylphosphonate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and other monoacylphosphine oxides; 1-hydroxycyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one and other hydroxyacetophenones; benzoin, benzil, 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-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholin-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone and other acetophenones; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone and other thioxanthones; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-pentylanthraquinone, 2-aminoanthraquinone and other anthraquinones; acetophenone dimethyl ketal, benzil dimethyl ketal and other ketals; ethyl 4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, ethyl p-dimethylbenzoate and other benzoates;1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethanone 1-(O-acetyl oxime) and other oxime esters; bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyrrol-1-yl)ethyl)phenyl]titanium and other titanocene compounds; phenyl disulfide 2-nitrofluorene, benzoin, benzoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like. The photopolymerization initiator can be used alone or in combination of two or more kinds.

[0069] (C) The content of the photopolymerization initiator is preferably 5 to 25 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin (A) based on the solid content. When it is 5 parts by mass or more, the surface curability becomes good, and when it is 25 parts by mass or less, halation is less likely to occur and good resolution is obtained.

[0070] (D) Photosensitive monomer

[0071] The photosensitive thermosetting resin composition capable of forming the cured product of the present invention may contain a commonly known photosensitive monomer. (D) The photosensitive monomer can 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) epoxy resin based on the irradiation of active energy rays and cures the photosensitive thermosetting resin composition.

[0072] Examples of the (D) photosensitive monomer preferably used in the present invention include methyl α-(allyloxymethyl)acrylate, or diacrylates of diols such as 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 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, diacrylates of diols obtained by adding at least one of ethylene oxide and propylene oxide to neopentyl glycol, diacrylates of diols such as ε-caprolactone-modified hydroxypivalic acid neopentyl glycol diacrylate, EO adduct diacrylate of bisphenol A, PO adduct diacrylate of bisphenol A, tricyclodecane dimethanol diacrylate, hydrogenated dicyclopentadienyl diacrylate, cyclohexyl diacrylate and other diacrylates having a cyclic structure, or bifunctional (meth)acrylates such as their corresponding methacrylate monomers, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolmethane triacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, epichlorohydrin-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, tetramethylolmethane tetraacrylate, EO-modified tris(acryloyloxyethyl) phosphate, epichlorohydrin-modified glycerol triacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxy pentaacrylate, or polyfunctional acrylates represented by their silsesquioxane-modified products, or their corresponding methacrylate monomers, trifunctional methacrylates, ε-caprolactone-modified tris(acryloyloxyethyl) isocyanurate and other polyfunctional (meth)acrylates, or combinations of two or more of them, etc.

[0073] The content of this (D) photosensitive monomer 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 (A) carboxyl group-containing resin in terms of solid content.

[0074] If the content of the (D) photosensitive monomer is within this range, the photosensitive thermosetting resin composition has sufficient photocurability, patterning becomes better during development, and the touch dryness also becomes good.

[0075] (E) Polytetrafluoroethylene fine powder

[0076] In the present invention, the inventors actively studied and found that adding a certain amount of polytetrafluoroethylene (PTFE, also known as Teflon, etc.) fine powder with a specific particle size range to the photosensitive thermosetting resin composition can improve the touch dryness of the solder resist ink, while improving the negative image indentation on the surface of the solder resist ink, enhancing the heat resistance, crack resistance, pencil hardness of the cured film, and also enhancing the CTI value and wear resistance of the cured film.

[0077] (E) The median particle size D50 of the polytetrafluoroethylene fine powder (the particle size value corresponding to a cumulative particle size distribution percentage of 50%) is 2.5 μm or more and 12 μm or less, preferably 3 μm or more and 10 μm or less. In addition, D90 (the particle size value corresponding to a cumulative particle size distribution percentage of 90%) is preferably 5 or more and 15 μm or less. If the median particle size D50 is less than 2.5 μm, the specific surface area of the smaller particle size polytetrafluoroethylene fine powder is relatively large, its oil absorption amount is relatively large, the viscosity and thixotropy index (TI value) of the ink are relatively large, and the ink properties (printability and dispersibility) do not meet the requirements, and it may also affect the wear resistance of the cured film. If the median particle size D50 exceeds 12 μm, due to the increase in particle size, the dispersibility of the composition will also deteriorate, the overall particles after dispersion of the powder material will be relatively large, and the roughness of the final coating will also increase. Under a relatively large roughness, the negative image indentation on the ink surface does not meet the requirements, and at the same time, the wear resistance of the cured film also decreases. If polytetrafluoroethylene fine powder with a larger particle size is used, although it may be possible to improve the negative image indentation on the ink surface, the printability of the composition deteriorates.

[0078] The above D50 and D90 of the polytetrafluoroethylene fine powder can be obtained by using a laser diffraction particle size distribution measuring device and a measuring device based on the dynamic light scattering method. As a measuring device based on the laser diffraction method, Microtrac MT3300EXII manufactured by MicrotracBEL Inc. can be cited, and as a measuring device based on the dynamic light scattering method, Nanotrac Wave II UT151 manufactured by MicrotracBEL Inc. can be cited.

[0079] The addition amount of the polytetrafluoroethylene fine powder is preferably 5% by weight to 20% by weight based on the total weight of the photosensitive thermosetting resin composition in terms of solid content, more preferably 7% by weight to 18% by weight. When within the above range, the CTI value of the cured film is greatly improved, and the wear resistance is also improved. If it is less than 5% by weight, it may not be possible to obtain a sufficiently high CTI value and wear resistance. If it exceeds 20% by weight, it may affect the printability and dispersibility.

[0080] In addition, the polytetrafluoroethylene fine powder can be incorporated into any component, for example, either into the main agent or the curing agent. From the perspective of better printability and dispersibility, it is preferably incorporated into the main agent.

[0081] As long as the particle size of the polytetrafluoroethylene fine powder meets the above specific range, commercially available products that are well-known and commonly used can be used. For example, MP1300 from Chemours (formerly DuPont) in the United States, PTFE-0104A and PTFE-0104S from Nanjing Tianshi New Materials Co., Ltd., etc.

[0082] (F) Inorganic filler

[0083] In the present invention, as the (F) inorganic filler, it is an inorganic filler other than the (E) polytetrafluoroethylene fine powder. For example, titanium oxide, silica, barium sulfate, barium titanate, Neuburg silica, talc, clay, magnesium carbonate, calcium carbonate, alumina, aluminum hydroxide, silicon nitride, aluminum nitride, etc. can be listed. Among them, from the perspectives of improving mechanical properties, heat resistance, processability, etc., at least any one of talc, silica, and barium sulfate is preferred. It is preferred to contain an inorganic filler in the main agent at least, and as the inorganic filler, barium sulfate is preferably used.

[0084] The inventors of the present invention also found that because barium sulfate has a large specific gravity (specific gravity is about 4.5), it is easy to disperse with the polytetrafluoroethylene fine powder (specific gravity is about 2.2) in the coating film, so all properties such as dispersibility and printability can be obtained well. Since silica (specific gravity is about 2.1) and talc (specific gravity is about 2.7) have a small specific gravity, they are easy to mix with the polytetrafluoroethylene fine powder and cannot fully exert the effect of the polytetrafluoroethylene fine powder. Therefore, the combination of polytetrafluoroethylene fine powder and barium sulfate is the most preferred.

[0085] As commercially available products of barium sulfate, for example, B-30 (manufactured by Sakai Chemical Industry Co., Ltd.) etc. can be listed.

[0086] The compounding amount of the (F) inorganic filler 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 (A) carboxyl group-containing resin based on solid content. When the compounding amount of the (F) inorganic filler is 35 parts by mass or more, there is a tendency to obtain a cured film with more excellent heat resistance to soldering, insulation reliability, and heat discoloration resistance. When the compounding amount of the (F) inorganic filler is 200 parts by mass or less, there is a tendency to obtain a photosensitive thermosetting resin composition with more excellent defoaming property, resolution, and deep part curability.

[0087] (F) The inorganic filler can be one that has been surface-treated, and it is more preferred to perform a surface treatment on their surfaces that can introduce a curable reaction group.

[0088] Here, the curable reactive group refers to a group that undergoes a curing reaction with (A) a carboxyl group-containing resin, (B) an epoxy resin, etc., and can be a photo-curable reactive group or a thermo-curable reactive group. As the photo-curable reactive group, examples include a methacryloyl group, an acryloyl group, a vinyl group, a styryl group, etc. As the thermo-curable reactive group, examples include an epoxy group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, an imino group, an oxetanyl group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, an oxazoline group, etc.

[0089] There is no particular limitation on the method for introducing a curable reactive group onto the surface of (F) the inorganic filler, and a publicly known and commonly used method can be used for the introduction. 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 the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent, etc. can be used. It should be noted that as the inorganic filler treated with a surface treatment without a curable reactive group, examples include silica-alumina surface treatment, titanate-based coupling agent treatment, aluminate-based coupling agent treatment, and organically treated inorganic filler, etc.

[0090] The average particle diameter (D50) of (F) the inorganic filler is 2000 nm or less, more preferably 1200 nm or less. In addition, its lower limit value is preferably 0.1 nm or more in terms of the average particle diameter (D50).

[0091] (F) The smaller the average particle diameter of the inorganic filler, the more the diffuse reflection during light irradiation is suppressed, and the microfabrication of the cured product pattern becomes easier. The average particle diameter (D50) can be determined using a laser diffraction particle size distribution measuring device and a measuring device based on the dynamic light scattering method. As the measuring device based on the laser diffraction method, MicrotracMT3300EXII manufactured by MicrotracBEL Inc. can be cited, and as the measuring device based on the dynamic light scattering method, Nanotrac Wave II UT151 manufactured by MicrotracBEL Inc. can be cited.

[0092] Solvent

[0093] In the present invention, for general purposes, for example, in order to prepare each component system of the photosensitive thermosetting resin composition and adjust its viscosity, a solvent can be used in at least one component system.

[0094] As the solvent, conventional organic solvents can be used. 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; polyol ethers; alkyl organic acid 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; polyol esters; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, solvent naphtha, and heavy aromatic solvent naphtha, etc.

[0095] These conventional organic solvents can be used alone or in combination of two or more.

[0096] With respect to 100 parts by mass of the carboxyl group-containing resin (A) based on solid content, the content of the conventional solvent in the main agent composition of the photosensitive thermosetting resin composition of the present invention is preferably in the range of 50 to 85 parts by mass, more preferably in the range of 55 to 70 parts by mass. The content of the conventional solvent in the curing agent composition of the photosensitive thermosetting 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.

[0097] Other components

[0098] In the photosensitive thermosetting resin composition of the present invention, within the scope not departing from the object of the present invention, further additives can of course be blended as other components according to need.

[0099] As such components, for example, coloring agents such as pigments and dyes, thermal polymerization inhibitors, thermal curing catalysts, ultraviolet absorbers, plasticizers, flame retardants, antistatic agents, antioxidants, thixotropic agents, anti-aging agents, antibacterial / mildew-proof agents, defoamers, leveling agents, rheology aids, anti-sagging agents, thickeners, adhesion improvers, thixotropy imparting agents, photoinitiator aids, sensitizers, photo base generators, thermoplastic resins, elastomers, organic fillers, mold release agents, surface treatment agents, dispersants, dispersion aids, surface modifiers, stabilizers, phosphors, cellulose resins, etc. can be cited.

[0100] Among them, melamine is preferably added. As an antioxidant, it improves the adhesion between the substrate and the cured film of the thermosetting composition by inhibiting the oxidation of the conductor (copper) on the substrate. As a thermal curing catalyst, it promotes the reaction between the epoxy group and the carboxyl group. Thereby, characteristics such as acid and alkali resistance, metal plating resistance, adhesion, and hardness of the dry film, curing agent, etc. formed by the photosensitive thermosetting resin composition can be improved.

[0101] In the main agent composition and the curing agent composition of the photosensitive thermosetting resin composition of the present invention, melamine can be optionally added to at least one of them. From the perspective of further facilitating the achievement of the above effects, it is more preferable to add melamine to the curing agent composition. As the blending amount of melamine, relative to 100 parts by mass of the carboxyl group-containing resin (A) based on solid content, it is preferably 0.1 to 20 parts by mass, and more preferably 0.5 to 15 parts by mass.

[0102] The main agent composition and the curing agent composition of the photosensitive thermosetting resin composition of the present invention can be prepared as follows: These respective components are mixed and dispersed in a specified amount, for example, using a three-roll mill or the like, whereby they can be prepared.

[0103] Dry film

[0104] A dry film can be made from the photosensitive thermosetting resin composition of the present invention. The dry film of the present invention has a resin layer, which is obtained by coating the photosensitive thermosetting resin composition of the present invention on a carrier film and drying. When forming the 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. After obtaining the photosensitive thermosetting resin composition of the present invention, it is directly or, if necessary, diluted with a high-boiling solvent to adjust to an appropriate viscosity, and then coated on the carrier film to a uniform thickness using a comma coater, a knife coater, a lip coater, a bar coater, an extrusion coater, an inverse coater, a transfer roll coater, an intaglio coater, a spray coater, etc. Thereafter, the coated composition is usually dried at a temperature of 50 to 130 °C for 1 to 30 minutes, whereby a resin layer can be formed. There is no particular limitation on the coating film thickness, and it is usually suitably selected in the range of 10 to 150 μm, preferably 20 to 60 μm, in terms of the dried film thickness.

[0105] As the carrier film, a plastic film is usually used. For example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, etc. can be used. There is no particular limitation on the thickness of the carrier film, and it is usually suitably selected in the range of 10 to 150 μm.

[0106] After forming a resin layer formed from the photosensitive thermosetting resin composition of the present invention on the carrier film, in order to prevent dust and the like from adhering to the surface of the resin layer, it is preferable to further laminate a peelable cover film on 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, as long as it is less adhesive than the adhesion between the resin layer and the carrier film when peeling off the cover film.

[0107] It should be noted that in the present invention, the photosensitive thermosetting resin composition of the present invention can also be coated on the above-mentioned cover film and dried to form a resin layer, and a carrier film is laminated on its surface. That is, in the present invention, when manufacturing a dry film, as the film for coating the curable composition of the present invention, either a carrier film or a cover film can be used.

[0108] Here, the photosensitive thermosetting resin composition of the present invention is adjusted to a viscosity suitable for the coating method using a high-boiling solvent, and after being coated on a substrate by methods such as dip coating, flow coating, roll coating, bar coating, screen printing, curtain coating, etc., the high-boiling solvent contained in the composition is volatilized and dried (preliminary drying) at a temperature of about 60 to 100 °C, thereby forming a non-tacky resin layer. In addition, in the case of a dry film formed by coating the above composition on a carrier film or a cover film and drying and winding it into a film, after laminating it on a substrate in such a way that the layer of the composition of the present invention is in contact with the substrate using a laminator or the like, the carrier film is peeled off, thereby forming a resin layer.

[0109] As the above-mentioned substrate, in addition to printed circuit boards and flexible printed circuit boards that have been previously formed with circuits made of copper or the like, the following can also be mentioned: copper-clad laminates of all grades (such as FR-4, etc.), metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer boards, 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 oxide (polyphenylene oxide), cyanate ester, etc.

[0110] Cured product

[0111] When forming a cured product using the photosensitive thermosetting resin composition of the present invention, the composition is coated on a substrate, the solvent is volatilized and dried, and a resin layer is obtained. The obtained resin layer is exposed (irradiated with light), so that the exposed part (the part irradiated with light) is cured. Specifically, by a contact or non-contact method, selective exposure is carried out using actinic energy rays through a patterned photomask, or direct pattern exposure is carried out using a laser direct exposure machine, and the unexposed part is developed using an alkaline aqueous solution (for example, a 0.3 to 3 mass% sodium carbonate aqueous solution), thereby forming an etching pattern. Further heating to a temperature of about 100 to 180 °C for thermal curing (post-curing), a cured film (cured product) with excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical properties can be formed.

[0112] The volatilization drying or thermal curing during the formation of the above-mentioned cured product can be carried out, for example, by using a hot air circulation drying furnace, an IR furnace, a hot plate, a convection oven, etc. (a method of making the hot air in the dryer convectively contact by using a device with a heat source using an air heating method utilizing steam and a method of blowing through a nozzle onto the support).

[0113] In addition, as the 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 by mounting 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 the light source or laser source of the direct drawing machine, the maximum wavelength can be in the range of 350 to 410 nm. The exposure amount for image formation varies depending on the film thickness, etc., and can generally be set to 20 to 1000 mJ / cm 2 and preferably can be set to 20 to 800 mJ / cm 2 within the range.

[0114] Next, as the developing step, the dried coating film after the exposure step is treated with a developer. Thereby, the unexposed portion in the coating film is removed, and a pattern film of the curable composition of the present invention can be formed.

[0115] Here, as the method used in this developing step, an immersion method, a pouring method, a spraying method, a brushing method, etc. can be used. As the developer, an aqueous sodium carbonate solution with a mass concentration of 0.5 to 5% can generally be used, and other alkaline aqueous solutions can also be used, such as: alkaline aqueous solutions of potassium hydroxide, sodium hydroxide, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc.

[0116] In this developing step, it is carried out at a developer temperature of 20 to 40 °C and a developing time of within 180 seconds.

[0117] It should be noted that in this developing step, if necessary, the obtained pattern film is cleaned with a rinsing solution. As the rinsing solution, distilled water, methanol, ethanol, isopropyl alcohol, etc. can be used alone or in combination.

[0118] Electronic component

[0119] In addition, the present invention can also provide an electronic component having the above-mentioned cured product.

[0120] The photosensitive thermosetting resin composition or dry film of the present invention can be used for protective films, electrical insulation layers, encapsulation materials for printed circuit boards, semiconductor components, etc., encapsulation materials for built-in electronic components, component built-in layers, adhesive layers for fixing electronic components, etc., and is particularly suitable for semiconductor devices in electrical products, transportation means, etc. under harsh conditions such as humidity, high temperature and high pressure, such as the PCB boards of air conditioners, water heaters, washing machines, and charging components of new energy vehicles.

[0121] It should be noted that in the present invention, an electronic component refers to a component used in an electronic circuit, and in addition to active components such as printed circuit boards, transistors, light-emitting diodes, and laser diodes, it also includes passive components such as resistors, capacitors, inductors, and connectors.

[0122] Hereinafter, an embodiment of the present invention will be specifically shown, but of course, it is not intended to limit the scope of the invention related to the claims of the present invention.

[0123] In addition, unless otherwise specified, the "parts" and "%" shown are based on mass.

[0124] Examples

[0125] [Synthesis Example: Synthesis of Novolac-Type Carboxyl-Containing Resin]

[0126] 1070 g (number of glycidyl groups (total number of aromatic rings): 5.0 moles) of o-cresol novolac-type epoxy resin (manufactured by DIC Corporation, EPICLON N-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 put into 600 g of diethylene glycol monoethyl ether acetate, heated to 100 °C and stirred until uniformly dissolved. Then, 4.3 g of triphenylphosphine was added, and after reacting at 110 °C for 2 hours, the temperature was raised to 120 °C and reacted for another 12 hours. 415 g of diethylene glycol monoethyl ether acetate and 456.0 g (3.0 moles) of tetrahydrophthalic anhydride were added to the obtained reaction solution, and the reaction was carried out at 110 °C for 4 hours, followed by cooling to obtain a carboxyl-containing vinyl ester resin (varnish). The solid content concentration of the carboxyl-containing vinyl ester resin (varnish) thus obtained was 64% by mass, and the acid value of the solid content was 89 mgKOH / g. In addition, the weight average molecular weight (Mw) of the obtained carboxyl-containing vinyl ester resin was 9000. It should be noted that the weight average molecular weight of the obtained resin was measured by a high performance liquid chromatograph equipped with 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.

[0127] [Examples 1 to 2 and Comparative Examples 1 to 6]

[0128] After premixing the respective components shown in Table 1 in the respective compounding amounts in a blender, kneading was carried out using a three-roll mill to prepare photosensitive thermosetting resin compositions (two-component systems formed from a main agent composition and a curing agent composition) of Examples 1 to 2 and Comparative Examples 1 to 6, respectively.

[0129] [Table 1]

[0130]

[0131] The respective components described in Table 1 are as follows.

[0132] *1: (A) Novolak type carboxyl group-containing resin obtained by a synthesis example, solid content 64%, solvent component (diethylene glycol monoethyl ether acetate (conventional solvent)) 35%, manufactured by DIC Zhangjiagang Chemical Co., Ltd.

[0133] *2: Rheology aid: BENATHIX, manufactured by Elementis

[0134] *3: Phthalocyanine blue: FASTOGEN Blue 5380, manufactured by DIC Corporation

[0135] *4: Defoaming agent: KS-66, manufactured by Shin-Etsu Chemical Co., Ltd.

[0136] *5: (C) Photoinitiator: DETX, manufactured by Tianjin Jiuri New Materials Co., Ltd.

[0137] *6: (C) Photoinitiator: #907: α-aminobenzophenone-based photoinitiator (Omnirad 907 manufactured by IGM Resins) (2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one)

[0138] *7: Organic solvent: diethylene glycol monoethyl ether acetate, manufactured by Shanghai Hongze Chemical Co., Ltd.

[0139] *8: Silicon dioxide: L-300, manufactured by Tosoh Silica Corporation

[0140] *9: Talc: LMP-100, manufactured by Fuji Talc Industry Co., Ltd.

[0141] *10: Barium sulfate: B-30, manufactured by Sakai Chemical Industry Co., Ltd.

[0142] *11: (E) Polytetrafluoroethylene fine powder D50: 3 - 10 μm

[0143] *12: Polytetrafluoroethylene fine powder D50: > 20 μm

[0144] *13: Polytetrafluoroethylene fine powder, D50: < 1μm

[0145] *14: Polytetrafluoroethylene fine powder, D50: 1 - 2μm

[0146] *15: Polytetrafluoroethylene fine powder, D50: 15 - 20μm

[0147] *16: (B) Liquid epoxy resin: N - 770 - 75EA, manufactured by DIC Corporation, a novolak - type polyfunctional epoxy resin, solid content 75%

[0148] *17: (D) Photosensitive monomer: DPHA, dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.

[0149] *18: Organic solvent: diethylene glycol monoethyl ether acetate, manufactured by Shanghai Hongze Chemical Co., Ltd.

[0150] *19: Organic solvent: S - 150, heavy aromatic solvent naphtha, manufactured by Shanghai Hongze Chemical Co., Ltd.

[0151] *20: Melamine: MELAMINE - JC, manufactured by Shanghai Xindi Chemical Co., Ltd.

[0152] *21: (B) Powdered epoxy resin: TGIC - G, manufactured by Shanghai Xindi Chemical Co., Ltd.

[0153] *22: Barium sulfate: B - 30, manufactured by Sakai Chemical Industry Co., Ltd.

[0154] For the main agent compositions, curing agent compositions, and photosensitive thermosetting resin compositions obtained by mixing them in the obtained examples and comparative examples, the following tests were conducted.

[0155] <Dispersibility>

[0156] Using a 0 - 50μm doctor blade fineness gauge, after wiping the fineness gauge clean before testing and waiting for the solvent to completely volatilize, confirm that there is no residue on the surface, and use an antistatic brush to remove the surface dust. The scale 0 of the fineness measurement table faces the tester. Take a small amount of the sample and place it above the maximum scale. The amount of the sample should be more than the volume of the deep groove of the fineness gauge. The blade of the doctor blade cuts horizontally in a direction perpendicular to the deep groove of the measurement table and presses the fineness gauge vertically downward against the plane of the fineness gauge. Push the blade towards the scale 0 at the same speed (it takes about 4 seconds to scrape the entire length).

[0157] Line evaluation

[0158] When lines longer than about 5mm appear due to the sliding friction between the particles of the sample being tested and the doctor blade, and when 3 or more lines appear within the same scale range in the same groove, the upper scale line within the scale range where the lines are located is taken as the reading. If the readings in the left and right grooves are inconsistent, the larger reading is taken as the test result.

[0159] Particle Assessment

[0160] Observe the particles in the groove. If there are 5 or more particles in the same groove and the same scale range, the upper scale line in the scale range is taken as the reading. If the readings of the left and right grooves are inconsistent, the larger reading shall be taken as the test result.

[0161] Judgment criteria: If the line evaluation is 15μm or less and the particle evaluation is 35μm or less, the dispersion is judged to be good "○";

[0162] Otherwise, it was judged as poor dispersion "×".

[0163] <Printability>

[0164] The photosensitive thermosetting resin composition obtained by fully mixing the main agent composition and the curing agent composition of the above-mentioned embodiments and comparative examples was printed using a scraper with a hardness of 70 to 80 and a polyester fiber mesh of 100 meshes. The carrier was selected as a FR-4 substrate (solar ink test substrate pattern T-5, T-44), the distance between the screen and the substrate was about 3.2 mm, the scraper angle was 60 to 80 degrees, the printing speed was 10 to 20 cm / sec, and the wet film thickness was about 35 μm. After printing, the coating surface was visually evaluated for bubbles, shrinkage holes, orange peel, etc.

[0165] Judgment criteria: If there are no bubbles, shrinkage holes, orange peel and other phenomena on the coating surface, it is judged as good printability "○";

[0166] Otherwise, the printability was judged as poor "×".

[0167] <Dryness to touch>

[0168] The photosensitive thermosetting resin compositions of the above-mentioned embodiments and comparative examples were 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.

[0169] ○: No stickiness at all, △: Slightly sticky, ×: Sticky

[0170] <Surface film impression>

[0171] On a copper-clad laminate that has been polished by a polishing roller, the photosensitive thermosetting resin compositions of the above-mentioned embodiments and comparative examples are coated on the entire surface by screen printing, and dried at 80°C for 30 minutes to prepare a substrate. After the substrate is completely cooled, an exposure process is carried out using a film, and after exposure, the film indentation on the coating surface is visually observed.

[0172] Judgment standard: If there is no obvious film indentation on the coating surface, it is judged as good film indentation "○";

[0173] Otherwise, it is judged as "×" for the underfilm indentation defect.

[0174] <Whiteness resistance>

[0175] The curable resin compositions of the above-mentioned examples and comparative examples were uniformly coated onto a copper-clad laminate substrate pretreated by polishing and grinding by screen printing, dried at 80 °C for 30 minutes, cooled to room temperature, and a resin layer with a thickness of 25 μm was formed. For the resin layer, a 7KW conventional halogen exposure machine (HMW-680GW manufactured by ORC) equipped with a halogen light source was used to perform full-surface exposure with an exposure amount of 400 mJ / cm 2 . Then, development was carried out for 60 seconds under the condition of a spray pressure of 0.2 MPa using a 1% mass concentration aqueous sodium carbonate solution at 30 °C. Subsequently, the composition was dried (post-cured) for 60 minutes using a hot air circulation drying oven adjusted to 150 °C to obtain an evaluation substrate.

[0176] The above-mentioned evaluation substrate coated with a rosin-based soldering flux was immersed in a solder bath pre-set at 288 °C for 10 seconds, directly placed in boiling water at 100 °C and boiled for 30 min, and then taken out to observe whether the surface color turned white.

[0177] ○: No whitening

[0178] △: Slight whitening

[0179] ×: Severe whitening

[0180] <Heat resistance>

[0181] The curable resin compositions of the above-mentioned examples and comparative examples were uniformly coated onto a copper-clad laminate substrate pretreated by polishing and grinding by screen printing, dried at 80 °C for 30 minutes, cooled to room temperature, and a resin layer with a thickness of 25 μm was formed. For the resin layer, a 7KW conventional halogen exposure machine (HMW-680GW manufactured by ORC) equipped with a halogen light source was used to perform full-surface exposure with an exposure amount of 400 mJ / cm 2 . Then, development was carried out for 60 seconds under the condition of a spray pressure of 0.2 MPa using a 1% mass concentration aqueous sodium carbonate solution at 30 °C. Subsequently, the composition was dried (post-cured) for 60 minutes using a hot air circulation drying oven adjusted to 150 °C to obtain an evaluation substrate.

[0182] The above-mentioned evaluation substrate coated with a rosin-based soldering flux was immersed in a solder bath pre-set at 288 °C, the soldering flux was washed with a modified alcohol, and the swelling / peeling of the resist layer was evaluated visually. The judgment criteria are as follows.

[0183] ○: No peeling was observed even after repeating the 10-second immersion 4 times or more

[0184] △: Slightly exfoliates when immersed for more than 4 times for 10 seconds

[0185] ×: The resist layer bulges and exfoliates when immersed for 10 seconds within 4 times

[0186] <Crack resistance>

[0187] The photosensitive thermosetting resin compositions of the examples and comparative examples were screen-printed and coated over the entire surface of a substrate with a 2 mm copper wire pattern formed thereon so as to have a thickness of 25 μm, and dried in a hot air circulation drying oven at 80 °C for 30 minutes. After cooling to room temperature, pattern exposure was performed using a 7KW conventional halogen exposure machine (ORC HMW–680GW) equipped with a halogen light source. Then, after developing for 60 seconds in a 1 wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30 °C, curing was performed in a hot air circulation drying oven at 150 °C for 60 minutes. By irradiating ultraviolet rays in a UV conveyor oven under the condition of an accumulated exposure dose of 2000 mJ / cm 2 a thermal and cold cycle crack resistance evaluation substrate having 17 resist patterns with a right-angled shape was fabricated. A plurality of the evaluation substrates fabricated as above were placed in a thermal and cold cycle machine that cycled between -40 °C (15 minutes) and 125 °C (15 minutes), and different cycle numbers were set to perform a thermal and cold shock cycle test (TCT test). Then, the appearance at each cycle number was observed, and the maximum cycle number at which no cracks occurred was recorded (for the presence or absence of cracks, see Figure 1 and Figure 2 ), and the evaluation criteria are as follows.

[0188] ○: No cracks after more than 1000 cycles

[0189] ×: Cracks occur below 1000 cycles

[0190] <Pencil hardness>

[0191] The photosensitive thermosetting resin compositions of the above examples and comparative examples were screen-printed and coated over the entire surface of a copper-clad laminate substrate that had been pretreated by polishing and grinding, dried at 80 °C for 30 minutes, cooled to room temperature, and a resin layer with a thickness of 40 μm was formed. For the resin layer, pattern exposure was performed using a 7KW conventional halogen exposure machine (ORC HMW–680GW) equipped with a halogen light source. Then, after developing for 60 seconds in a 1 wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30 °C, the composition was then dried (post-cured) in a hot air circulation drying oven at 150 °C for 60 minutes to obtain an evaluation substrate. The pencil hardness of the resin surface of the evaluation substrate was measured according to JIS K 5600-5-4, and the measurement results are shown in Table 1. The evaluation criteria are as follows.

[0192] ◎: Pencil hardness above 6H

[0193] 〇: Pencil hardness above 4H and below 6H

[0194] △: Pencil hardness below 4H

[0195] <CTI value>

[0196] The photosensitive thermosetting resin compositions of the above-mentioned examples and comparative examples were coated uniformly on a copper-clad laminate substrate pretreated by polishing and grinding through screen printing, dried at 80 °C for 30 minutes, cooled to room temperature, and a resin layer with a thickness of 40 μm was formed. For the resin layer, pattern exposure was carried out using a 7KW traditional halogen exposure machine (ORC HMW–680GW) equipped with a halogen light source. Then, after developing for 60 seconds in a 1wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30 °C, the composition was dried (post-cured) for 60 minutes in a hot air circulation drying oven at 150 °C to obtain an evaluation substrate. The CTI value of the substrate surface coating was measured:

[0197] Measuring equipment: Tracking resistance tester, model SH5240

[0198] Testing standard: IEC 60112:2020

[0199] Test liquid: 0.1% ammonium chloride (NH4Cl) solution

[0200] Evaluation method: The highest test voltage value (V) at which the surface coating of the evaluation substrate can withstand the test process of 50 drops without leakage tracking failure and without continuous burning on the sample surface and without the operation of the overcurrent device.

[0201] <Wear resistance>

[0202] The photosensitive thermosetting resin compositions of the above-mentioned examples and comparative examples were coated uniformly on a copper-clad laminate substrate pretreated by polishing and grinding through screen printing, dried at 80 °C for 30 minutes, cooled to room temperature, and a resin layer with a thickness of 40 μm was formed. For the resin layer, pattern exposure was carried out using a 7KW traditional halogen exposure machine (ORC HMW–680GW) equipped with a halogen light source. Then, after developing for 60 seconds in a 1wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30 °C, the composition was dried (post-cured) for 60 minutes in a hot air circulation drying oven at 150 °C to obtain an evaluation substrate. The wear resistance of the substrate surface coating was measured:

[0203] Testing equipment: Reciprocating abrasion tester

[0204] Testing standard: ISO 7784-1:2016

[0205] Evaluation method: Use a grinding wheel model CS-10, with a load of 500 g per wheel, a speed of 60 rpm, and conduct a reciprocating wear test for 100 times to evaluate the scratch condition on the coating surface after the test.

[0206] 5 Inconspicuous scratches;

[0207] 4 Slightly obvious scratches;

[0208] 3 Obvious scratches on the surface, but not serious;

[0209] 2 Obvious scratches on the surface;

[0210] 1 Clearly visible scratches

[0211] As can be seen from the results shown in Table 1, by using polytetrafluoroethylene fine powder within a specific particle size range, the photosensitive thermosetting resin compositions of Examples 1 and 2 of the present invention have excellent ink properties (dispersibility, printability, touch dryness, and ink surface negative indentation), and at the same time, the cured products have excellent whitening resistance, heat resistance, crack resistance, pencil hardness, CTI value, and wear resistance.

[0212] On the other hand, the main agent composition of Comparative Example 1 does not contain polytetrafluoroethylene fine powder, and the touch dryness and ink surface negative indentation are not good. At the same time, the whitening resistance, heat resistance, crack resistance, pencil hardness, CTI value, and wear resistance of the cured product are all not good. The particle size of the polytetrafluoroethylene fine powder used in Comparative Example 3 is slightly smaller (D50 = 1 - 2 μm), and the dispersibility and printability of the composition are not good. The particle size of the polytetrafluoroethylene fine powder used in Comparative Example 4 is slightly larger (D50 = 15 - 20 μm), the dispersibility and ink surface negative indentation of the composition are not good, and at the same time, the wear resistance of the cured product is reduced. In Comparative Example 2, a larger amount of polytetrafluoroethylene fine powder with a larger particle size (D50 > 20 μm) is used. Although the ink surface negative indentation is improved compared with Comparative Example 4, the printability of the composition becomes poor, and the dispersibility of the composition and the wear resistance of the cured product are still not good. The total amount of inorganic fillers in Comparative Example 5 is the same as that in Example 2, and more low - specific - gravity talc powder is used to replace polytetrafluoroethylene fine powder. The printability of the composition becomes poor, the touch dryness and ink surface negative indentation are not good, and the whitening resistance, heat resistance, pencil hardness, and wear resistance of the cured film are not good. In Comparative Example 6, a larger amount of polytetrafluoroethylene fine powder with a smaller particle size (D50 < 1 μm) is used. Compared with Comparative Example 2 with a slightly smaller particle size of polytetrafluoroethylene fine powder, although the wear resistance is improved, the dispersibility and printability of the composition are still not good.

[0213] It can be seen that the photosensitive thermosetting resin composition of the present invention has excellent ink properties, and at the same time, the whitening resistance, heat resistance, crack resistance, pencil hardness, CTI value and wear resistance of the formed cured film are further improved, and it is particularly suitable for semiconductor devices of electrical products, transportation means, etc. under harsh conditions such as humidity, high temperature and high pressure, such as PCB boards of air conditioners, water heaters, washing machines and charging components of new energy vehicles, etc.

Claims

1. A photosensitive thermosetting resin composition, which is composed of at least a resin composition of a two-component system, and is characterized in that, The photosensitive thermosetting resin composition contains: (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photopolymerization initiator, (D) a photosensitive monomer, and (E) polytetrafluoroethylene fine powder, The (A) carboxyl group-containing resin and the (C) photopolymerization initiator are respectively contained in different resin compositions from the (B) epoxy resin and the (D) photosensitive monomer, The median particle size D50 of the (E) polytetrafluoroethylene fine powder is 2.5 μm or more and 12 μm or less.

2. The photosensitive thermosetting resin composition according to claim 1, characterized in that, The (A) carboxyl group-containing resin, the (C) photopolymerization initiator, and the (E) polytetrafluoroethylene fine powder are respectively contained in different resin compositions from the (B) epoxy resin and the (D) photosensitive monomer.

3. The photosensitive thermosetting resin composition according to claim 1 or 2, characterized in that, The median particle size D50 of the (E) polytetrafluoroethylene fine powder is 3 μm or more and 10 μm or less.

4. The photosensitive thermosetting resin composition according to claim 1 or 2, characterized in that, The content of the (E) polytetrafluoroethylene fine powder is 5% by weight to 20% by weight based on the total weight of the solid components of the photosensitive thermosetting resin composition.

5. The photosensitive thermosetting resin composition according to claim 1 or 2, characterized in that, It further contains (F) an inorganic filler, and the (F) inorganic filler is an inorganic filler other than the (E) polytetrafluoroethylene fine powder.

6. The photosensitive thermosetting resin composition according to claim 5, characterized in that, The specific gravity of the (F) inorganic filler is 3.5 or more.

7. The photosensitive thermosetting resin composition according to claim 5, characterized in that, The (F) inorganic filler is barium sulfate.

8. A dry film, which is obtained by coating the photosensitive thermosetting resin composition according to any one of claims 1 to 7 on a carrier film and drying.

9. A cured product, characterized in that, It is obtained by curing the photosensitive thermosetting resin composition according to any one of claims 1 to 7.

10. A cured product, characterized in that, It is obtained by curing the resin layer of the dry film according to claim 8.

11. An electronic component, characterized in that, It has the cured product according to claim 9 or 10.

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