Photocurable thermosetting resin composition, dry film, cured product, and electronic component

Abstract

The present invention provides a photocurable thermosetting resin composition, a dry film, a cured product, and an electronic component. Namely, a photocurable thermosetting resin composition having excellent printability, a dry film having a resin layer formed of the resin composition, which is excellent in crack resistance and adhesion, a cured product formed of the resin composition, which is excellent in crack resistance and adhesion, and an electronic component are provided. The photocurable thermosetting resin composition comprises a carboxyl group-containing resin, a photopolymerization initiator, an epoxy resin comprising an epoxy resin containing a dicyclopentadiene skeleton, a stress relaxing agent, and an inorganic filler, the stress relaxing agent being any one or more of an elastomer having two or more Tgs apart by 50°C or more at 200°C and a rubber particle having a shell layer and a core layer, the content of the stress relaxing agent being 1 to 13% by weight of the solid content of the composition, the inorganic filler comprising talc, the content of the inorganic filler being 5 to 20% by weight of the solid content of the composition.

Description

TECHNICAL FIELD

[0001] The present application relates to a photocurable thermosetting resin composition, a dry film having a resin layer formed from the resin composition, a cured product formed from the resin composition, and an electronic component. BACKGROUND

[0002] In recent years, in semiconductor devices for vehicles such as automobiles, trains, ships, and aircraft, there is a tendency to use a solder resist for printed circuit boards that is a high-reliability electronic material. For this solder resist for high-reliability electronic materials, the level of demand for crack resistance in cold and heat cycles is increasing.

[0003] To address this problem, for example, methods such as low CTE (low thermal expansion, CTE: Coefficient of Thermal Expansion), low elastic modulus, high toughness, and the like can be cited. As one of the methods to achieve high toughness, a stress relaxer such as a rubber particle is used. This method achieves local low elasticity by containing a structure that is easily broken or deformed inside.

[0004] For example, in Patent Literature 1, a resin composition containing a resin having a bisphenol skeleton containing an ethylenic unsaturated group and a carboxyl group, a solid epoxy resin, an inorganic filler material having an average particle diameter of 0.5 μm or more, a photopolymerization initiator, and a rubber particle is disclosed.

[0005] PRIOR ART DOCUMENTS

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2019-119818 SUMMARY

[0007] Problem to be solved by the invention

[0008] For a solder resist curable resin composition, existing curable resin compositions are compounded with silica or talc, but if a large amount of silica or talc is compounded, there is a problem that the defoaming property at the time of printing of the composition decreases. If too much talc is compounded, there is also a problem that the adhesion property deteriorates.

[0009] On the other hand, the inventors of the present application found that when the method of using a stress relaxer improves cold and heat cycle reliability, the adhesion force is affected as the strength of the coating film decreases.

[0010] To address the above-described problems, the present application aims to provide a photocurable thermosetting resin composition excellent in printability, a dry film having a resin layer formed from the resin composition, and a cured product formed from the resin composition, which is excellent in crack resistance and adhesion force, and an electronic component.

[0011] As a result of intensive studies, the inventors have found that, by combining at least talc, a specific epoxy resin, and a specific stress relaxant in a photocurable thermosetting resin composition, it is possible to improve crack resistance, adhesion, and bubble elimination, and by further including a specific compound having an ethylenic unsaturated group and a specific inorganic filler, it is possible to solve all of the above problems, thereby completing the present application.

[0012] That is, the present application is as described below.

[0013] [Item 1]

[0014] A photocurable thermosetting resin composition characterized by comprising (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) an epoxy resin, (D) a stress relaxant, and (E) an inorganic filler,

[0015] The (C) epoxy resin comprises an epoxy resin containing a dicyclopentadiene skeleton,

[0016] The (D) stress relaxant is any one or more of an elastomer having two or more Tgs apart by 50°C or more at 200°C, and a rubber particle having a shell layer and a core layer, and the content thereof is 1 to 13% by weight of the solid content of the composition,

[0017] The (E) inorganic filler comprises talc, and the content of the (E) inorganic filler is 5 to 20% by weight of the solid content of the composition.

[0018] [Item 2]

[0019] The photocurable thermosetting resin composition according to Item 1, characterized in that the (E) inorganic filler comprises silica having a (meth)acryloyl group on the surface.

[0020] [Item 3]

[0021] The photocurable thermosetting resin composition according to Item 2, characterized in that the content of the silica having a (meth)acryloyl group on the surface is 10 to 50% by weight of the solid content of the composition.

[0022] [Item 4]

[0023] The photocurable thermosetting resin composition according to Item 2, characterized in that the content of the silica having a (meth)acryloyl group on the surface is 15 to 30% by weight of the solid content of the composition.

[0024] [Item 5]

[0025] The photocurable thermocurable resin composition according to item 1, characterized in that the (C) epoxy resin comprises (C1) a phenol novolak type epoxy resin and (C2) an epoxy resin containing a dicyclopentadiene skeleton.

[0026] [Item 6]

[0027] The photocurable thermocurable resin composition according to item 5, characterized in that the (C1) phenol novolak type epoxy resin and (C2) epoxy resin containing a dicyclopentadiene skeleton are contained in a ratio of 1:10 to 1:0.5.

[0028] [Item 7]

[0029] The photocurable thermocurable resin composition according to item 5, characterized in that the (C1) phenol novolak type epoxy resin and (C2) epoxy resin containing a dicyclopentadiene skeleton are contained in a ratio of 1:5 to 1:1.

[0030] [Item 8]

[0031] The photocurable thermocurable resin composition according to item 1, characterized by further comprising a compound having an ethylenic unsaturated group.

[0032] [Item 9]

[0033] The photocurable thermocurable resin composition according to item 8, characterized in that the compound having an ethylenic unsaturated group has an isocyanuric acid ring.

[0034] [Item 10]

[0035] A dry film characterized by having a resin layer formed of the photocurable thermocurable resin composition according to any one of items 1 to 9.

[0036] [Item 11]

[0037] A cured product characterized by being obtained by curing the photocurable thermocurable resin composition according to any one of items 1 to 9.

[0038] [Item 12]

[0039] An electronic component characterized by having the cured product of item 11.

[0040] Effects of the invention

[0041] According to the present application, it is possible to provide a photocurable thermocurable resin composition excellent in printability, a dry film having a resin layer formed of the resin composition, and a cured product excellent in crack resistance and adhesion force formed of the resin composition, and an electronic component. Attached Figure Description

[0042] Figure 1 This is a diagram illustrating the substrate used to evaluate defoaming performance in the embodiments.

[0043] Figure 2 A diagram illustrating a substrate used to evaluate the surface condition after development in an embodiment.

[0044] Figure 3 A diagram illustrating the substrate used to evaluate the adhesion force in the embodiments.

[0045] Explanation of reference numerals

[0046] D fixture

[0047] L1 adhesive

[0048] L2 Photocurable and thermocurable resin compositions

[0049] L3 Copper Foil Laminate Detailed Implementation

[0050] This invention relates to a photocurable and thermocurable resin composition, characterized in that it comprises (A) a carboxyl-containing resin, (B) a photopolymerization initiator, (C) an epoxy resin, (D) a stress relaxant, and (E) an inorganic filler.

[0051] The epoxy resin (C) comprises an epoxy resin containing a dicyclopentadiene backbone.

[0052] The stress relaxant (D) is any one or more of an elastomer having two or more Tg values ​​separated by more than 50°C at 200°C and rubber particles having a shell and a core layer, and its content is 1 to 13% by weight of the solid components of the composition.

[0053] The inorganic filler (E) comprises talc, and the content of the inorganic filler (E) is 5 to 20% by weight of the solid components of the composition.

[0054] (A) carboxyl group-containing resin

[0055] The carboxyl group-containing resin (A) in the photocurable thermosetting resin composition of the present application can use a known resin containing a carboxyl group in the molecule for imparting alkali developability. From the aspects of photocurability and developability, a carboxyl group-containing resin having an olefinic unsaturated double bond in the molecule is particularly preferred. Further, the unsaturated double bond is more preferably derived from acrylic acid or methacrylic acid or a derivative thereof. As the carboxyl group-containing resin (A), a carboxyl group-containing resin using an epoxy resin as a starting material, a carboxyl group-containing resin using a phenol compound as a starting material is preferred. More preferably, a multifunctional epoxy resin is reacted with (meth)acrylic acid, and a carboxyl group-containing photosensitive resin is obtained by adding an acid anhydride to the hydroxyl group present in the side chain.

[0056] Specific examples of the carboxyl group-containing resin are shown below.

[0057] (1) A carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid such as (meth)acrylic acid and an unsaturated group-containing compound such as styrene, α-methylstyrene, (meth)acrylic acid lower alkyl ester, isobutylene, etc.

[0058] (2) A carboxyl group-containing polyurethane resin obtained by polyaddition of a diisocyanate compound such as aliphatic diisocyanate, branched aliphatic diisocyanate, alicyclic diisocyanate, aromatic diisocyanate, etc., with a carboxyl group-containing diol compound such as dimethylolpropionic acid, dimethylolbutyric acid, etc., and a diol compound such as polycarbonate-based polyol, polyether-based polyol, polyester-based polyol, polyolefin-based polyol, acrylic polyol, bisphenol A-based alkylene oxide adduct diol, compound having phenolic hydroxyl group and alcoholic hydroxyl group, etc.

[0059] (3) A carboxyl group-containing polyurethane resin having a terminal carboxyl group obtained by polyaddition of a diisocyanate compound such as aliphatic diisocyanate, branched aliphatic diisocyanate, alicyclic diisocyanate, aromatic diisocyanate, etc., with a diol compound such as polycarbonate-based polyol, polyether-based polyol, polyester-based polyol, polyolefin-based polyol, acrylic polyol, bisphenol A-based alkylene oxide adduct diol, compound having phenolic hydroxyl group and alcoholic hydroxyl group, etc., and by reacting the terminal of the polyurethane resin with an acid anhydride.

[0060] (4) A carboxyl group-containing photosensitive polyurethane resin obtained by polyaddition of a diisocyanate, (meth)acrylic ester or a partial acid anhydride-modified product thereof of a 2-functional epoxy resin such as bisphenol A-type epoxy resin, hydrogenated bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, dinaphthylol-type epoxy resin, diphenol-type epoxy resin, carboxyl group-containing diol compound, and diol compound.

[0061] (5) A carboxyl group-containing polyurethane resin which is end (meth) acrylated by adding to the synthesis of the resin of (2) or (4) above a compound having one hydroxyl group and one or more (meth) acryloyl groups in the molecule such as a hydroxyalkyl (meth) acrylate.

[0062] (6) A carboxyl group-containing polyurethane resin which is end (meth) acrylated by adding to the synthesis of the resin of (2) or (4) above a compound having one isocyanate group and one or more (meth) acryloyl groups in the molecule such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate.

[0063] (7) A carboxyl group-containing photosensitive resin obtained by reacting a 2-functional or 2-functional or more polyfunctional epoxy resin as described later with (meth) acrylic acid, and adding to the hydroxyl group present in the side chain a dibasic anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride. Here, the polyfunctional epoxy resin is preferably a solid.

[0064] (8) A carboxyl group-containing photosensitive resin obtained by further epoxidizing the hydroxyl group of a 2-functional epoxy resin as described later with epichlorohydrin to obtain a polyfunctional epoxy resin, and reacting the polyfunctional epoxy resin with (meth) acrylic acid, and adding to the resulting hydroxyl group a dibasic anhydride. Here, the 2-functional epoxy resin is preferably a solid.

[0065] (9) A carboxyl group-containing photosensitive resin obtained by adding to a polyfunctional phenol compound such as a novolak a cyclic ether such as oxirane, or a cyclic carbonate such as propylene carbonate, partially esterifying the resulting hydroxyl group with (meth) acrylic acid, and reacting the remaining hydroxyl group with a polybasic anhydride.

[0066] (10) A carboxyl group-containing photosensitive resin obtained by further adding to the resins of (1) to (9) a compound having one epoxy group and one or more (meth) acryloyl groups in the molecule such as glycidyl (meth) acrylate, α-methyl glycidyl (meth) acrylate.

[0067] (A) The carboxyl group-containing resin can be used not limited to these, and one kind can be used or a plurality of kinds can be mixed. From the viewpoint of the rigidity and heat resistance of the dry film and the cured product, the carboxyl group-containing resin of (7) above is more preferable.

[0068] Note that (meth) acrylate here is a term which collectively refers to acrylate, methacrylate and mixtures thereof, and the same applies to other similar expressions below.

[0069] (A) The carboxyl group-containing resin has a large number of free carboxyl groups in the side chain of the main chain polymer, and thus development with a dilute aqueous alkali solution is possible. In addition, the acid value of this carboxyl group-containing resin is preferably 40 to 200 mgKOH / g. When the acid value of the (A) carboxyl group-containing resin is 40 mgKOH / g to 200 mgKOH / g, the adhesion of the cured coating film is obtained, the alkali development becomes easy, the dissolution of the exposed portion by the developer is suppressed, the line does not become finer than necessary, and the drawing of a normal resist pattern becomes easy. More preferably, it is 45 to 120 mgKOH / g.

[0070] In addition, the weight average molecular weight of this carboxyl group-containing resin varies depending on the resin skeleton, and is generally preferably 2,000 to 150,000. When it is in the range of 2,000 to 150,000, the tack-free property is good, the moisture resistance of the cured coating film after exposure is good, and film reduction does not easily occur at the time of development. In addition, when it is in the range of the above weight average molecular weight, the resolution is improved, the developability is good, and the storage stability becomes good. More preferably, it is 5,000 to 100,000.

[0071] The compounding amount of the (A) carboxyl group-containing resin in the photocurable thermosetting resin composition is preferably 20 to 80% by weight. When it is 20% by weight or more and 80% by weight or less, the film strength is good, and the tackiness of the composition can be reduced, and the coatability and the like are excellent.

[0072] (B) photopolymerization initiator

[0073] As the photopolymerization initiator used in the photocurable thermosetting resin composition of the present application, there is no particular limitation as long as it is a photopolymerization initiator generally used for photocurable thermosetting resin compositions.

[0074] As the photopolymerization initiator, known substances can be used, and examples that can be given are benzoin, benzoin methyl ether, benzoin ethyl ether, and the like; benzoin and alkyl ethers thereof; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 4-(1-tert-butyldioxy-1-methylethyl)acetophenone, and the like; acetophenone; 2-methylanthraquinone, 2-pentylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and the like; thioxanthone; isopropyl thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diisopropyl thioxanthone, 2-chlorothioxanthone, and the like; ketal; benzophenone, 4-(1-tert-butyldioxy-1-methylethyl)benzophenone, 3,3',4,4'-tetra(tert-butyldioxycarbonyl)benzophenone, and the like; and xanthone.

[0075] In addition, as the photopolymerization initiator, an oxime ester-based photopolymerization initiator having an oxime ester group, an alkylphenone-based photopolymerization initiator, an α-aminophenone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, a titanocene-based photopolymerization initiator, or the like can also be used.

[0076] As the oxime ester-based photopolymerization initiator, commercially available products such as Irgacure OXE01, Irgacure OXE02 manufactured by BASF Japan, Ltd., N-1919, NCI-831 manufactured by ADEKA CORPORATION, and the like can be given. A photopolymerization initiator having two oxime ester groups in the molecule can be preferably used, and specifically, an oxime ester compound having a carbazole ring structure can be given.

[0077] As the alkylphenone-based photopolymerization initiator, commercially available products such as α-hydroxyalkylphenone-based Omnirad 184, Omnirad 1173, Omnirad 2959, Omnirad 127 manufactured by IGM Resins B.V., and the like can be given.

[0078] As the α-aminophenone-based photopolymerization initiator, specifically, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone, 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 the like can be given. As commercially available products, Omnirad 907, Omnirad 369, Omnirad 379, and the like manufactured by IGM Resins B.V. can be used.

[0079] As the acylphosphine oxide-based photopolymerization initiator, specifically, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, and the like can be given. As commercially available products, Omnirad TPO manufactured by IGM Resins, Omnirad 819 manufactured by IGM Resins B.V., and the like can be used.

[0080] As the aforementioned titanocene-based photopolymerization initiator, specifically, bis(cyclopentadienyl)-diphenyltitanium, bis(cyclopentadienyl)-titanium dichloride, bis(cyclopentadienyl)-bis(2,3,4,5,6-pentafluorophenyl) titanium, bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyrrol-1-yl)phenyl) titanium, and the like can be given. As commercially available products, Omnirad 784 manufactured by IGM Resins B.V. and the like can be given.

[0081] As the photopolymerization initiator, a thioxanthone-based and an acylphosphine oxide-based photopolymerization initiator are preferably used. More preferably, an isopropyl thioxanthone-based and a bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide are used. By using a thioxanthone-based and an acylphosphine oxide-based photopolymerization initiator, a pattern of a cured product in which the deep curing property is excellent and undercut is inhibited can be obtained.

[0082] The compounding amount of the photopolymerization initiator is preferably 0.1 to 25 parts by weight, more preferably 1 to 20 parts by weight, with respect to 100 parts by weight of the carboxyl-containing photosensitive resin. By compounding within the above range, a cured film in which the photocurability and developability are excellent, the adhesion and PCT resistance are also increased, and further the chemical resistance such as electrolytic plating resistance is also excellent can be obtained.

[0083] (C) epoxy resin

[0084] In the photocurable thermosetting resin composition of the present application, as the epoxy resin, at least an epoxy resin having a dicyclopentadiene skeleton is used. When an epoxy resin having a dicyclopentadiene skeleton is used, a cured product having excellent adhesion to a substrate can be obtained. As commercially available products, for example, HP7200, HP7200H, and the like having a dicyclopentadiene skeleton manufactured by DIC Corporation can be mentioned. In addition to the epoxy resin having a dicyclopentadiene skeleton, an epoxy resin having at least two epoxy groups in the molecule, i.e., a multifunctional epoxy resin, can be suitably used. As commercially available products, for example, jER828, jER834, jER1001, jER1004 manufactured by Mitsubishi Chemical Corporation, EPICLON 840, 850, 850S, 1050, 2055 manufactured by DIC Corporation, EPOTOTE YD-011, YD-013, YD-127, YD-128 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., D.E.R. 317, D.E.R. 331, D.E.R. 661, D.E.R. 664 manufactured by Dow Chemical Company, Sumi-Epoxy ESA-011, ESA-014, ELA-115, ELA-128 manufactured by Sumitomo Chemical Company (all are trade names) bisphenol A type epoxy resins; jERYL903 manufactured by Mitsubishi Chemical Corporation, EPICLON 152, EPICLON 165 manufactured by DIC Corporation, EPOTOTE YDB-400, YDB-500 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., D.E.R. 542 manufactured by Dow Chemical Company, Sumi-Epoxy ESB-400, ESB-700 manufactured by Sumitomo Chemical Company (all are trade names) brominated epoxy resins; jER152, jER154 manufactured by Mitsubishi Chemical Corporation, D.E.N. 431, D.E.N. 438 manufactured by Dow Chemical Company, EPICLON N-730, EPICLON N-770, EPICLON N-865 manufactured by DIC Corporation, EPOTOTE YDB-400, YDB-500 manufactured by NIPPON STEEL Chemical & Material Co., Ltd.manufactured by DIC Corporation, jER807 manufactured by Mitsubishi Chemical Corporation, EPOTOTE YDF-170, YDF-175, YDF-2004, etc. (all are trade names) bisphenol F type epoxy resins manufactured by NIPPON STEEL Chemical & Material Co., Ltd., EPOTOTE ST-2004, ST-2007, ST-3000 (trade names), YX8034, etc. hydrogenated bisphenol A type epoxy resins manufactured by Mitsubishi Chemical Corporation, jER604, NIPPON STEEL Chemical & Material Co., Ltd.glycidyl amine type epoxy resins such as EPOTOTE YH-434 manufactured by EPOTOTE Co., Ltd., Sumi-Epoxy ELM-120 manufactured by Sumitomo Chemical Co., Ltd., and the like (all are trade names); hydantoin type epoxy resins; alicyclic epoxy resins such as CELLOXIDE 2021P manufactured by Daicel Corporation (trade name); triphenylolmethane type epoxy resins such as YL-933 manufactured by Mitsubishi Chemical Corporation, EPPN-501, EPPN-502, and the like manufactured by Japan Epoxy Resin Co., Ltd. (all are trade names); xylene glycol type or biphenol type epoxy resins such as YL-6056, YX-4000, YL-6121 (all are trade names) manufactured by Mitsubishi Chemical Corporation, or a mixture thereof; bisphenol S type epoxy resins such as EBPS-200 manufactured by Japan Epoxy Resin Co., Ltd., EPX-30 manufactured by ADEKA CORPORATION, EXA-1514 manufactured by DIC Corporation (trade names); bisphenol A novolak type epoxy resins such as jER 157S (trade name) manufactured by Mitsubishi Chemical Corporation; tetraphenylol ethane type epoxy resins such as jERYL-931 (trade name) manufactured by Mitsubishi Chemical Corporation; heterocyclic type epoxy resins such as TEPIC manufactured by Nissan Chemical Industries, Ltd. (trade name); phthalic acid diglycidyl ester resins such as BRENMAR DGT manufactured by Nippon Oil Corporation; tetraglycidyl xylylene acyl ethane resins such as ZX-1063 manufactured by NIPPON STEEL Chemical & Material Co., Ltd.; naphthalene skeleton-containing epoxy resins such as ESN-190, ESN-360 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., HP-4032, EXA-4750, EXA-4700 manufactured by DIC Corporation; glycidyl methacrylate copolymer type epoxy resins such as CP-50S, CP-50M manufactured by Nippon Oil Corporation; further, copolymer epoxy resins of cyclohexyl maleimide and glycidyl methacrylate; CTBN-modified epoxy resins (for example, YR-102, YR-450 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., and the like); and the like, but are not limited to these. These epoxy resins can be used alone or in combination of two or more.

[0085] Among them, the (C) epoxy resin particularly preferably contains (C1) a phenol novolak type epoxy resin and (C2) an epoxy resin containing a dicyclopentadiene skeleton.

[0086] The content ratio (weight ratio) of (C1) the phenol novolac type epoxy resin to (C2) the epoxy resin having a dicyclopentadiene skeleton is preferably 1 : 10 to 1 : 0.5, more preferably 1 : 5 to 1 : 1. When the content of (C2) the epoxy resin having a dicyclopentadiene skeleton is 5 parts by weight or less relative to 1 part by weight of (C1) the phenol novolac type epoxy resin, the crosslinking density increases, the breaking strength rises, and the adhesion improves. On the other hand, when the content of (C2) the epoxy resin having a dicyclopentadiene skeleton is 1 part by weight or more relative to 1 part by weight of (C1) the phenol novolac type epoxy resin, a cured product having an excellent opening shape can be obtained.

[0087] The content of (C) the epoxy resin is preferably 1 to 50% by weight relative to the solid content of the composition.

[0088] (D) stress relaxation agent

[0089] (D) the stress relaxing agent used in the photocurable thermosetting resin composition of the present application is any one or more of an elastomer having two or more glass transition temperatures (hereinafter also referred to as Tg) apart from each other by 50°C or more at 200°C, and a rubber particle having a shell layer and a core layer.

[0090] As the elastomer having two or more Tg apart from each other by 50°C or more at 200°C, an elastomer satisfying the condition that the midpoint temperature Tg measured by a differential scanning calorimeter (DSC) based on JIS K7121 (1987) is used without particular limitation, for example, a rubber, a thermoplastic elastomer, a functional group-containing elastomer, a block copolymer, and the like can be suitably used.

[0091] As the rubber, either a diene-based rubber or a non-diene-based rubber can be used, and a publicly known and customary product can be used alone or in a mixture of two or more.

[0092] As the thermoplastic elastomer, a styrene-based elastomer, an olefin-based elastomer, a polyurethane-based elastomer, a polyester-based elastomer, a polyol-based elastomer, a polyamide-based elastomer, an acrylic-based elastomer, a silicone-based elastomer, and the like can be listed, and can be used alone or in a mixture of two or more.

[0093] As the functional group-containing elastomer, from the viewpoint of stretchability, a polyurethane-based elastomer or an olefin-based elastomer is preferred, and from the viewpoint of solvent resistance, an elastomer having a functional group such as a (meth)acryloyl group, an anhydride group, a carboxyl group, and an epoxy group is preferred.

[0094] As the block copolymer, a block copolymer having a hard segment and a soft segment can be listed, and can be used alone or in a mixture of two or more.

[0095] The elastomer of the present application can be a commercially available product. As commercially available products, for example, a copolymer of polymethyl acrylate and polybutyl acrylate can be mentioned. Specifically, M52N manufactured by Arkema Co., Ltd., KURARITY LA3320 manufactured by Kuraray Co., Ltd., and KURARITY LA2330 manufactured by Kuraray Co., Ltd. can be listed.

[0096] As the rubber particles having a shell layer and a core layer, there is no particular limitation as long as a shell layer is formed by subjecting a resin exhibiting rubber elasticity to a chemical crosslinking treatment, and a minute particle body of a resin which is insoluble and infusible in an organic solvent. For example, a minute particle body in which a core layer formed of a rubbery polymer is coated with a shell layer of a glassy polymer, a minute particle body in which a core layer formed of a glassy polymer is coated with a shell layer of a rubbery polymer, or a minute particle body in which a three-layer structure of an outermost layer is further provided outside these shell layers, and the like can be used. Furthermore, as necessary, in order to impart compatibility and reactivity with a thermosetting resin, the shell layer or the outermost layer can be modified with a carboxyl group, an epoxy group, a hydroxyl group, or the like to introduce a functional group. As the core layer, polybutadiene, an acrylic polymer, polyisoprene, and the like can be listed, and as the shell layer, an alkyl acrylate-alkyl methacrylate copolymer, an alkyl methacrylate-styrene copolymer, an alkyl acrylate copolymer, and the like can be listed. As a preferred aspect, the core layer uses a rubbery polymer such as polybutadiene having a glass transition temperature of room temperature or lower, and the shell layer uses an alkyl acrylate copolymer having a glass transition temperature of 60°C or higher, and furthermore, from the viewpoint of adhesion, it is preferable to modify the surface of the shell layer with a carboxyl group. Such rubber particles having a shell layer and a core layer are different from inorganic fillers, because the rubbery polymer of the core layer moderates the curing shrinkage deformation due to thermosetting, and furthermore, the compatibility with the thermosetting component is better than that of inorganic fillers, so that no defects such as an air layer are generated at the particle interface, so that the electric insulation properties are not reduced. In addition, because the adhesion of the shell polymer to the coated object is better than that of inorganic fillers, and the rubbery polymer of the core layer moderates external stress, as a result, the adhesion to the coated object is not reduced. Furthermore, because it is a fine particle, an effect of thickening the composition and improving thixotropy can also be expected, and the printability can be improved without using inorganic fillers. Furthermore, because the specific gravity of the organic fine particle is not greater than that of inorganic fillers, it is difficult to settle in the coating film, and it is easy to form unevenness on the surface. Furthermore, because the surface of the fine particle is a glassy polymer, even in the case where unevenness derived from the fine particle is formed on the surface of the coating film, no tackiness is generated, and an effect of improving the tackiness can also be expected. In this way, by using the rubber particles having a shell layer and a core layer, a photocurable thermosetting resin composition in which the balance of printability, tackiness, matting property, electric insulation properties, and adhesion to the coated object is excellent can be obtained.

[0097] As commercially available products, for example, XER-91 (manufactured by Nippon Gomu Seiyaku Co., Ltd.), STAPHYLOID AC3355, AC3816, AC3816N, AC3832, AC4030, AC3364, IM101 (all manufactured by AICA Kogyo Co., Ltd.), PARALOID EXL2655, EXL2602 (all manufactured by Waco Chemical Co., Ltd.), and the like can be mentioned.

[0098] Also, the core can be a rubber composed of crosslinked styrene and butadiene, and the shell can be a core / shell polymer such as a methacrylate-butadiene-styrene (MBS) copolymer as a polymethyl acrylate (for example, ACRYLOID KM653 and KM680 available from Rohm and Haas (Philadelphia, PA), particles having a core containing polybutadiene and a shell containing polymethyl methacrylate (for example, KANE ACE M 511, M521, B11A, B22, B31, and M901 available from Kaneka Corporation (Houston, TX), and CLEARSTRENGTH C223 available from ATOFINA (Philadelphia, PA)), particles having a polysiloxane core and a polyacrylate shell (for example, CLEARSTRENGTH S-2001 available from ATOFINA, and GENIOPER LP22 available from Wacker-Chemie GmbH, Wacker Silicones (Munich, Germany)), particles having a polyacrylate core and a polymethyl methacrylate shell (for example, PARALOID EXL2330 available from Rohm and Haas, and STAPHYLOID AC3355 and AC3395 available from Takeda Pharmaceutical Co., Ltd. (Osaka, Japan)), particles having an MBS core and a polymethyl methacrylate shell (for example, PARALOID EXL2691A, EXL2691, and EXL2655 available from Rohm and Haas), and the like, and mixtures thereof.

[0099] The stress relaxing agent can be used alone or in combination of two or more. The content of the stress relaxing agent is preferably 1 to 13% by weight, relative to the solid content of the composition. If the amount of the stress relaxing agent is too small, the breaking strength and the cold and hot cycle crack resistance are insufficient. On the other hand, if the amount of the stress relaxing agent is too large, the defoaming property is deteriorated, and the surface of the substrate after development becomes whitened.

[0100] The stress relaxing agent is a rubber particle having a shell layer and a core layer, and whitening of the surface of the coating film after development by an aqueous alkaline solution can be further suppressed.

[0101] (E) inorganic filler

[0102] (E) Inorganic filler for relaxing stress caused by curing shrinkage, adjusting linear expansion coefficient. As such inorganic filler, known inorganic fillers generally used in resin compositions can be used. Specifically, for example, non-metallic fillers such as silica, barium sulfate, calcium carbonate, silicon nitride, aluminum nitride, boron nitride, alumina, magnesium oxide, aluminum hydroxide, magnesium hydroxide, titanium oxide, mica, talc, organic bentonite, and metallic fillers such as copper, gold, silver, palladium, silicon can be listed. These can be used alone or in combination of two or more.

[0103] As the shape of the inorganic filler, spherical, acicular, flaky, scaly, hollow, irregular, hexagonal, cubic, and flaky shapes can be listed, and from the viewpoint of high filling of the inorganic filler, a spherical shape is preferred.

[0104] Among these, silica and calcium carbonate which are excellent in low hygroscopicity and low volume expansion are preferred. As the silica, both amorphous and crystalline can be used, and a mixture thereof can also be used. From the viewpoint of achieving high filling, amorphous (fused) silica of a spherical shape is preferred. In addition, as the calcium carbonate, both natural heavy calcium carbonate and synthetic precipitated calcium carbonate can be used.

[0105] In particular, in order to obtain excellent cold and hot cycle crack resistance, the photocurable thermosetting resin composition of the present application contains talc as a necessary component. The content of talc is 5 to 20% by weight, preferably 5 to 15% by weight, in the solid components of the composition. If the amount of talc is insufficient, the cold and hot cycle crack resistance is insufficient. On the other hand, if the amount of talc is excessive, the debubbling property and the breaking strength are insufficient, and the adhesion becomes poor.

[0106] From the viewpoint of further improving the breaking strength and the adhesion, as the silica, further preferably a silica having a (meth)acryl group on the surface, i.e., a (meth)acryl-modified silica is used. The content of the (meth)acryl-modified silica is preferably 10 to 50% by weight, more preferably 15 to 50% by weight, in the solid components of the composition. If the surface-modified silica is contained, the interface breakage of the filler and the resin is suppressed, and the adhesion can be further improved. If the content of the surface-modified silica is within the above range, a photocurable thermosetting resin composition which is more excellent in debubbling property can be obtained, and the amount of solvent can also be saved.

[0107] Compound having an ethylenically unsaturated group

[0108] The photocurable thermosetting resin composition of the present application can further contain a compound having an ethylenic unsaturated group.

[0109] As such a compound, conventionally known polyesters (meth)acrylates, polyether (meth)acrylates, carbonate (meth)acrylates, epoxy (meth)acrylates, urethane (meth)acrylates can be used, and specifically, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, diacrylates of diols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, propylene glycol, acrylamides such as N,N-dimethylacrylamide, N-hydroxymethyl acrylamide, N,N-dimethylaminopropyl acrylamide, aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropyl acrylate, polybasic acrylates of polyols such as hexanediol, trimethylolpropane, pentaerythritol, di-pentaerythritol, trihydroxyethyl isocyanurate or oxirane adducts or propylene oxide adducts or ε-caprolactone adducts thereof, polybasic acrylates of phenoxy acrylates, bisphenol A diacrylate, oxirane adducts or propylene oxide adducts of these phenols, polybasic acrylates of glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, tri-glycidyl isocyanurate, and at least any one of acrylates obtained by directly acrylating polyether polyols, polycarbonate diols, hydroxyl-terminated polybutadienes, polyester polyols or urethane acrylates by means of diisocyanate, and methacrylates corresponding to the above acrylates can be used.

[0110] From the viewpoint of further improving adhesion, the compound having an ethylenically unsaturated group preferably has an isocyanuric acid ring, and more preferably a di- or higher functional (meth)acrylate having an isocyanuric acid ring. If such a compound having an ethylenically unsaturated group is contained, curing shrinkage is further suppressed, and adhesion can be further improved.

[0111] As a commercially available product of the compound having an ethylenically unsaturated group and an isocyanuric acid ring, for example, A-9300, A-9200YN, A-9300-1Cl, A-9300-3Cl (all manufactured by Shin-Nakamura Chemical Co., Ltd.), DA-MGIC, MA-DGIC (all manufactured by Shikoku Chemicals Corporation), and the like can be mentioned.

[0112] The compounding amount of the compound having an ethylenically unsaturated group is preferably 5 to 100 parts by weight, more preferably 10 to 90 parts by weight, and further preferably 15 to 85 parts by weight, relative to 100 parts by weight of the carboxyl group-containing resin. Within the above compounding amount, photocurability is improved, pattern formation becomes easy, and the strength of the cured film is also improved.

[0113] Additive

[0114] In the photocurable thermosetting resin composition of the present application, a coloring pigment, a defoaming agent, a coupling agent, a leveling agent, a sensitizer, a release agent, a lubricant, a plasticizer, an antioxidant, a UV absorber, a flame retardant, a polymerization inhibitor, a thickening agent, an adhesion aid, a crosslinking agent, and the like, which are known additives, can be further added as needed. In addition, various reinforcing fibers can be used as the reinforcing fiber, and a fiber-reinforced composite material can be used.

[0115] Organic solvent

[0116] In the photocurable thermosetting resin composition of the present application, an organic solvent can be used for the purpose of the synthesis of the above-mentioned (A) carboxyl group-containing resin, the adjustment of the composition, the adjustment of the viscosity at the time of coating on a substrate or a support film, and the like.

[0117] As the solvent, there can be mentioned ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum-based solvents, and the like. More specifically, there can be mentioned 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, and dipropylene glycol diethyl ether; esters such as ethyl acetate, butyl acetate, diethylene glycol ethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate; alcohols such as ethanol and propanol; aliphatic hydrocarbons such as octane and decane; petroleum-based solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha; and the like. These organic solvents can be used alone or in the form of a mixture of two or more kinds.

[0118] Dry film

[0119] The photocurable thermosetting resin composition of the present application can also be formed into a dry film having a support (carrier) film and a resin layer formed of the photocurable thermosetting resin composition described above formed on the support film. When the dry film is formed, the photocurable thermosetting resin composition of the present application is diluted with the organic solvent described above to an appropriate viscosity, and is coated on a carrier film in a uniform thickness by a comma coater, a knife coater, a lip coater, a bar coater, a squeeze coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater, or the like, and is dried at a temperature of usually 50 to 130°C for 1 to 30 minutes to obtain a film. The film thickness is not particularly limited, and is usually appropriately selected within a range of 1 to 150 μm, preferably 10 to 60 μm, in terms of the film thickness after drying.

[0120] As the support film, a plastic film, preferably a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamide-imide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of the support film is not particularly limited, and is usually preferably in the range of 10 to 150 μm.

[0121] After forming the resin layer of the photocurable thermosetting resin composition of the present application on the support film, further, for the purpose of preventing dust from adhering to the surface of the resin layer or the like, it is preferable to laminate a peelable protective (cover) film on the surface of the resin layer. As the peelable protective film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used, as long as the protective film is such that the adhesion of the resin layer to the protective film is smaller than the adhesion of the resin layer to the support film when the protective film is peeled.

[0122] Note that, in the present application, the resin layer can be formed by applying the photocurable thermosetting resin composition of the present application on the above-mentioned protective film and drying, and laminating the support film on the surface thereof. That is, in the present application, in the production of the dry film, as the film on which the photocurable thermosetting resin composition of the present application is applied, either of the support film and the protective film can be used.

[0123] Cured product

[0124] The cured product of the present application is obtained by curing the above-mentioned photocurable thermosetting resin composition of the present application or the resin layer of the above-mentioned dry film of the present application, and has high insulation reliability.

[0125] Printed circuit board

[0126] The printed circuit board of the present application has a cured product obtained from the photocurable thermosetting resin composition or the resin layer of the dry film of the present application. As the method for producing the printed circuit board of the present application, for example, the photocurable thermosetting resin composition of the present application is adjusted to a viscosity suitable for the coating method using the above-mentioned organic solvent, and is applied on a substrate using a dipping method, a flow coating method, a roll coating method, a bar coating method, a screen printing method, a curtain coating method, or the like, and then the composition is dried (temporarily dried) by volatilizing the organic solvent contained therein at a temperature of 60 to 1000C, thereby forming a tack-free resin layer. In the case of the dry film, the resin layer is attached to the substrate in a state in which the resin layer is in contact with the substrate using a laminator or the like, and then the carrier film is peeled, thereby forming the resin layer on the substrate.

[0127] As the above-mentioned substrate, in addition to a printed circuit board, a flexible printed wiring board, on which a circuit is formed in advance by copper or the like, there can be mentioned, for example, copper-clad laminated boards of all grades (FR-4 or the like) of materials such as paper phenol resin, paper epoxy resin, glass cloth epoxy resin, glass polyimide resin, glass cloth / nonwoven fabric epoxy resin, glass cloth / paper epoxy resin, synthetic fiber epoxy resin, fluororesin / polyethylene / polyphenylene ether resin, polyphenylene oxide / cyanate ester resin, and the like, which are used for high-frequency circuits, and metal substrates, polyimide films, polyethylene terephthalate films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer boards, and the like.

[0128] The volatile drying after the application of the photocurable thermosetting resin composition of the present application can be performed by using a hot air circulation type drying furnace, an IR furnace, a hot plate, a convection type oven, or the like (a method in which a drying machine is contacted with hot air convection using a device provided with a heat source using steam, a method in which air is blown onto a support using a nozzle, or the like).

[0129] After the formation of the resin layer on the substrate, exposure is performed selectively using active energy rays through a photomask having a prescribed pattern, and the unexposed portions are developed using a dilute alkali aqueous solution (for example, a 0.3 to 3% by weight sodium carbonate aqueous solution) to form a pattern of cured products. Further, after the irradiation of active energy rays to the cured products, heat curing is performed (for example, at 100 to 220°C), or active energy rays are irradiated after the heat curing, or the final complete curing (main curing) is performed by heat curing alone to form a cured film having excellent adhesion, hardness, and the like.

[0130] As the exposure machine used in the above-mentioned irradiation of active energy rays, a device in which a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a mercury short-arc lamp, or the like is mounted, and ultraviolet rays are irradiated in the range of 350 to 450 nm, and further, a direct writing device (for example, a laser direct imaging device in which an image is directly drawn by laser light using CAD data from a computer) can be used. As the light source or the laser light source of the direct writing machine, the maximum wavelength can be in the range of 350 to 450 nm. The exposure amount for image formation differs depending on the film thickness or the like, and can be set in the range of 10 to 1000 mJ / cm 2 , preferably 20 to 800 mJ / cm 2 .

[0131] As the developing method, an immersion method, a spray method, a spray coating method, a brush coating method, or the like can be used, and as the developing solution, an alkali aqueous solution of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, or the like can be used.

[0132] The photocurable thermosetting resin composition of the present application is suitable for forming a cured film on an electronic component, particularly suitable for forming a cured film on a printed circuit board, more suitable for forming a permanent cover film, further suitable for forming a solder resist layer, an interlayer insulating layer, a cover layer. In addition, it is suitable for forming a permanent cover film (particularly a solder resist layer) of a printed circuit board requiring high reliability, such as a package substrate, particularly for FC-BGA.

[0133] Examples

[0134] Hereinafter, the present application will be described in more detail using examples, but the present application is not limited to the examples. Note that "parts" and "%" below are all on a weight basis unless otherwise specified.

[0135] A photocurable thermosetting resin composition was prepared by mixing each component shown in Tables 1 and 2 in the proportions (parts by weight) shown in Tables 1 and 2, premixing with a blender, and then kneading with a three-roll mill. Note that the glass transition temperature (Tg) of LA3320 and BR-87 was obtained as the midpoint temperature using differential scanning calorimetry (DSC) based on JIS K7121 (1987). The measuring device was DSC7020 (manufactured by HITACHI), and the temperature increase rate was 10°C / minute.

[0136] [Table 1]

[0137]

[0138] [Table 2]

[0139]

[0140] A-1 Carboxyl group-containing resin of Synthesis Example 1, solid content 65%, equivalent to (7) carboxyl group-containing resin

[0141] B-1 TPO, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, acylophosphine oxide-based photopolymerization initiator (manufactured by IGM Resins B.V.)

[0142] B-2 ITX, isopropylthioxanthone (manufactured by DKSH JAPAN)

[0143] B-3 Omnirad 369, 2-benzyl-2-dimethylamino-l-(4-morpholinophenyl)-butan-l-one, α-aminophenylacetophenone-based photopolymerization initiator (manufactured by IGM Resins B.V.)

[0144] C-1 N-770-75EA, manufactured by DIC Corporation, multifunctional epoxy resin of novolak type, solid content 75%

[0145] C-2 HP-7200-52CA, manufactured by DIC Corporation, epoxy resin having a dicyclopentadiene skeleton, solid content 85%

[0146] D-1 KURARITY LA3320, elastomer having two or more Tgs apart by 50°C or more at 200°C, Tgl: 140°C, Tg2: -30°C, ΔTg = 170°C, manufactured by Kuraray Corporation

[0147] D-2 STAPHYLOID AC3355, microparticles having a core-shell structure, manufactured by AICA Corporation

[0148] D-3 Dianal BR-87, Tg: 105°C, manufactured by Mitsubishi Chemical Corporation

[0149] E-1 Talc, manufactured by FUJI TALC INDUSTRIAL

[0150] E-2 Spherical silica, manufactured by Admatechs

[0151] E-3 Silica having a surface with a methacryl group obtained in Synthesis Example 2

[0152] F-1 A-9300-1Cl, 3-functional (caprolactone-modified) isocyanuric acid acrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.

[0153] F-2 DPHA, dipentaerythritol hexaacrylate, manufactured by Wako Pure Chemical Industries, Ltd.

[0154] G-1 KS-66, defoaming agent, manufactured by Shin-Etsu Chemical Co., Ltd.

[0155] H-1 PGMEA, propylene glycol monomethyl ether acetate

[0156] Synthesis Example 1 (Carboxyl-containing Resin A-1)

[0157] To 600 g of diethylene glycol monoethyl ether acetate was added 1070 g of o-cresol novolak type epoxy resin (manufactured by DIC Corporation, EPICLON N-695, softening point 95°C, epoxy equivalent weight 214, average number of functional groups 7.6) (glycidyl group number (total number of aromatic rings): 5.0 moles), 360 g of acrylic acid (5.0 moles), and 1.5 g of hydroquinone, heated to 100°C and stirred, and uniformly dissolved. Then, 4.3 g of triphenylphosphine was added, and after heating to 110°C and reacting for 2 hours, the temperature was further increased to 120°C and reacted for 12 hours. To the obtained reaction liquid was added 415 g of aromatic hydrocarbon (SOLVESSO 150) and 534 g of methyl-5-norbornene-2,3-dicarboxylic anhydride (3.0 moles), and reacted at 110°C for 4 hours, and after cooling, a carboxyl group-containing cresol novolak type resin solution having a solid content of 65% and an acid value of 89 mgKOH / g was obtained. This was used as the carboxyl group-containing resin A-1.

[0158] Synthesis Example 2

[0159] After mixing 700 g of spherical silica manufactured by Admatechs Co., Ltd. and 300 g of PMA (propylene glycol monomethyl ether acetate) as a solvent, dispersion treatment was performed using a zirconia bead of 0.65 mm in a bead mill. Filtration was performed three times using a 3 μm filter, and a silica slurry having an average particle diameter of 0.7 μm was prepared.

[0160] To the silica slurry (PMA) having an average particle diameter of 0.7 μm obtained above (solid content 70% by weight), 4% by weight of a methacrylic acid-based silane was added based on the silica, and the mixture was treated in a bead mill for 10 minutes, and a silica surface-treated with a methacrylic acid-based silane was obtained. In addition, as the methacrylic acid-based silane, KBM-503 manufactured by Shin-Etsu Silicone Co., Ltd. was used.

[0161] Evaluation method of debubbling

[0162] A debubbling evaluation substrate was produced by screen printing the photocurable thermocurable resin composition of Examples 1 to 12 and Comparative Examples 1 to 8 on a substrate having a φ400 μm, pitch 600 μm opening pattern of copper 100 μm thick, and after standing at room temperature for 30 minutes, drying at 80°C for 30 minutes using a hot air circulation type drying oven. The debubbling evaluation substrate was observed using an optical microscope at 100 times, and the occurrence rate of bubbles at the copper opening was evaluated (refer to Figure 1 ).

[0163] ◎: Occurrence rate of bubbles less than 40%

[0164] 〇: Occurrence rate of bubbles 40% or more and less than 50%

[0165] : Bubble occurrence rate 50% or more

[0166] Bubble occurrence rate (%) = (number of cells in which bubbles exist / total number of cells 100) x 100%

[0167] Evaluation method of surface state after development

[0168] The photocurable thermocurable resin compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were each applied in a manner such that the thickness by screen printing became 40 μm on a copper-clad laminate, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, an exposure device equipped with a high-pressure mercury lamp was used to perform 100% exposure at 400 mJ / cm 2 The entire surface was exposed (evaluation substrate before development). Next, development was performed in a 1 wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30°C for 60 seconds, and an evaluation substrate after development was produced. For the obtained evaluation substrate, the values of the L*a*b color system on the copper were measured by the SCI method according to JIS Z8729 using the following spectrophotometer, and the difference ΔL value in the index indicating brightness, i.e., the L* value, before and after development was evaluated according to the following evaluation criteria.

[0169] : ΔL value 5 or less (see Figure 2 left photograph)

[0170] : ΔL value more than 5 and less than 10

[0171] : ΔL value 10 or more (see Figure 2 right photograph)

[0172] Spectrophotometer (CM-2600d manufactured by Konica Minolta)

[0173] Evaluation method of opening shape

[0174] The photocurable thermocurable resin compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were each applied in a manner such that the thickness by screen printing became 40 μm, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, an exposure device equipped with a high-pressure mercury lamp was used to perform 100% exposure at 400 mJ / cm 2 Pattern exposure was performed, and then development was performed in a 1 wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30°C for 60 seconds, and then curing was performed in a hot air circulation drying oven at 150°C for 60 minutes. Thus, an opening shape evaluation substrate in which an opening pattern of a hardened material 200 μm square was formed was produced. The opening cross section of the obtained evaluation substrate was observed by an optical microscope, and the opening shape was evaluated according to the following evaluation criteria based on the difference between the top end value and the bottom end value.

[0175] (Evaluation criteria)

[0176] ◎: (Top value - bottom value of opening) is less than 40 μm

[0177] O: (Top value - bottom value of opening) is 40 μm or more and less than 60 μm

[0178] Δ: (Top value - bottom value of opening) is 60 μm or more

[0179] Evaluation method of breaking strength

[0180] The photocurable thermocurable resin compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were applied by screen printing to a thickness of 40 μm on the glossy side (copper foil) of a GTS-MP foil (manufactured by Furukawa Circuit Foil Co., Ltd.) and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, exposure was performed using an exposure device equipped with a high-pressure mercury lamp at 400 mJ / cm 2 The entire surface was exposed. Next, after development in a 1 wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30°C for 60 seconds, curing was performed in a hot air circulation drying oven at 150°C for 60 minutes. After irradiation of ultraviolet rays in a UV transport oven at a cumulative exposure of 2000 mJ / cm 2 After peeling the cured film from the copper foil, a sample of a measurement size (10 mm x 100 mm, 40 μm) was cut out. The tensile rate (elongation at break) of the sample was measured according to JIS K 7127 at a tensile speed of 1.0 mm / minute and a temperature of 23°C.

[0181] The evaluation criteria were as follows

[0182] ◎: Breaking strength is 80 MPa or more

[0183] O: Breaking strength is 60 MPa or more and less than 80 MPa

[0184] Δ: Breaking strength is 40 MPa or more and less than 60 MPa

[0185] X: Breaking strength is less than 40 MPa

[0186] Evaluation method of cold-heat cycle crack resistance

[0187] The photocurable thermocurable resin compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were applied by screen printing to a thickness of 40 μm on a substrate on which a copper wire pattern of 2 mm was formed and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, exposure was performed using an exposure device equipped with a high-pressure mercury lamp at 400 mJ / cm 2After the pattern exposure, development was performed in 1 wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30°C for 60 seconds, and then curing was performed in a hot air circulation drying oven at 150°C for 60 minutes. A cold and hot cycle crack resistance evaluation substrate on which 17 3 mm square resist patterns were formed was produced by irradiating ultraviolet rays in a UV transport oven at a cumulative exposure of 2000 mJ / cm 2 The evaluation substrate was placed in a cold and hot cycle machine that performs temperature cycling between -65°C and 150°C, and TCT (Thermal Cycle Test) was performed. Then, the appearance at 1000 cycles was observed, the number of cracks was counted, and evaluation was performed according to the following evaluation criteria. In addition, the value "68" in the denominator is 4 corners (4) x 17 for the 3 mm square resist patterns, indicating 68 corners, and the values "30" and the like in the numerator indicate the number of cracks.

[0188] ◎: 20 / 68 or less

[0189] O: 21 / 68 or more and 30 / 68 or less

[0190] Δ: 31 / 68 or more and 40 / 68 or less

[0191] X: 41 / 68 or more

[0192] Adhesion evaluation method

[0193] The photocurable thermocurable resin compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were each applied to a copper-clad laminate board by screen printing so as to have a thickness of 20 μm, and drying was performed in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, the entire surface was exposed using an exposure device equipped with a high-pressure mercury lamp at 400 mJ / cm 2 After the pattern exposure, development was performed in 1 wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30°C for 60 seconds, and then curing was performed in a hot air circulation drying oven at 150°C for 60 minutes. A cold and hot cycle crack resistance evaluation substrate on which 17 3 mm square resist patterns were formed was produced by irradiating ultraviolet rays in a UV transport oven at a cumulative exposure of 2000 mJ / cm 2 After the pattern exposure, development was performed in 1 wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30°C for 60 seconds, and then curing was performed in a hot air circulation drying oven at 150°C for 60 minutes. A cold and hot cycle crack resistance evaluation substrate on which 17 3 mm square resist patterns were formed was produced by irradiating ultraviolet rays in a UV transport oven at a cumulative exposure of 2000 mJ / cm

[0194] As shown in Figure 3 , a jig was fixed to the adhesion evaluation substrate with an adhesive (Three Bond Co., Ltd. 2082C, curing conditions: 120°C for 60 minutes), and the peel strength of the jig was measured using a PosiTest AT-A manufactured by DeFelsko Co., Ltd. under the following conditions.

[0195] Test jig size: Φ 10 mm, test speed: 1.0 MPa / sec, test environment: 25°C

[0196] The results obtained were evaluated as follows.

[0197] ◎: more than 5.5 MPa

[0198] O: more than 4.5 MPa and 5.5 MPa or less

[0199] A: more than 3.5 MPa and 4.5 MPa or less

[0200] X: 3.5 MPa or less

[0201] As shown in Tables 1 and 2, if the compounding amount of (D) stress relaxer is insufficient, the breaking strength and the cold-heat cycle crack resistance are insufficient (Example 1 and Comparative Example 1). On the other hand, if the compounding amount of (D) stress relaxer exceeds the upper limit, the defoaming property becomes poor, the substrate surface after development becomes whitened, and the opening shape deteriorates (Example 1 and 2 and Comparative Example 2; Example 3 and 4 and Comparative Example 3). In addition, if (D) stress relaxer does not have two or more Tgs apart by 50°C or more at 200°C, the breaking strength, the cold-heat cycle crack resistance, and the adhesion are insufficient (Example 1 and Comparative Example 8). If the amount of talc is insufficient, the cold-heat cycle crack resistance is insufficient (Example 2 and 5 and Comparative Example 4 and 5). On the other hand, if the amount of talc exceeds the upper limit, the defoaming property and the breaking strength are insufficient, and the adhesion is greatly decreased (Example 6 and Comparative Example 6). If (C) epoxy resin does not contain an epoxy resin containing a dicyclopentadiene skeleton, the adhesion is insufficient (Example 1 and Comparative Example 7).

[0202] In addition, with respect to (E) inorganic filler, if silica having a (meth) acryloyl group on the surface is contained, the interface between the filler and the resin is inhibited from being broken, and the breaking strength and the adhesion are more excellent (Example 2 and Example 7). If the compounding amount of the above-mentioned silica having a (meth) acryloyl group on the surface is within the preferable range, the defoaming property is more excellent, and the amount of solvent can be saved (Example 3 and Example 9). In (C) epoxy resin, if the content ratio (solid content) of the dicyclopentadiene skeleton-containing epoxy resin and the phenol novolak-type epoxy resin is within the preferable range, the adhesion is more excellent (Example 1 and Example 10 and Example 11). In addition, as the preferable compound having an ethylenic unsaturated group, if a compound having an isocyanuric acid skeleton is contained, the adhesion is more excellent (Example 2 and Example 8). With respect to (B) initiator, in the case where a thioxanthone-based and an acyloxyphosphine-based photopolymerization initiator is used, the depth hardenability is improved, undercut can be inhibited, and the opening shape is more excellent (Example 1 and Example 12).

[0203] As can be seen from the results of the above-described examples and comparative examples, the photocurable thermocurable resin composition of the present application can obtain a cured product having excellent breaking strength, cold-heat cycle crack resistance, and adhesion. In addition, the photocurable thermocurable resin composition of the present application is excellent in defoaming property, can inhibit whitening of the substrate surface state after development, that is, is also excellent in printability.

Claims

1. A photocurable thermocurable resin composition, characterized by, A light-curable thermosetting resin composition comprising (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) an epoxy resin, (D) a stress relaxation agent, and (E) an inorganic filler, the (B) photopolymerization initiator is a thioxanthone-based photopolymerization initiator and an acyloxyphosphine-based photopolymerization initiator, the (C) epoxy resin comprises (C1) a phenol novolak-type epoxy resin and (C2) an epoxy resin containing a dicyclopentadiene skeleton, the (C1) phenol novolak-type epoxy resin and the (C2) epoxy resin containing a dicyclopentadiene skeleton are contained in a ratio of 1:5 to 1:1, the (D) stress relaxation agent is any one or more of an elastomer having two or more Tgs apart by 50°C or more at 200°C and a rubber particle having a core layer and a shell layer, and the content thereof is 1 to 13% by weight of the solid content of the composition, the (E) inorganic filler comprises talc and silica having a (meth)acryloyl group on the surface, the content of the talc is 5 to 15% by weight of the solid content of the composition, and the content of the silica having a (meth)acryloyl group on the surface is 15 to 30% by weight of the solid content of the composition, the light-curable thermosetting resin composition further contains a compound having an ethylenically unsaturated group and an isocyanuric acid ring.

2. A dry film, characterized by, A resin layer formed of the light-curable thermosetting resin composition according to claim 1.

3. A cured product, characterized by, It is a cured product obtained by curing the light-curable thermosetting resin composition according to claim 1.

4. An electronic component, characterized by The cured product according to claim 3.

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