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

Abstract

To provide a photosensitive resin composition which enables the increase in resolution, and which makes possible to obtain a hardened material superior in adhesion, hard to cause underfill bleeding, and satisfactory in underfill wetting extendability, and others.SOLUTION: Disclosed are a photosensitive resin composition and others. The photosensitive resin composition comprises (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photoinitiator, (D) an inorganic filler, and (E) a silane coupling agent, in which an amount of the inorganic filler (D) blended is less than 35 mass% to a total amount of solid contents, and the silane coupling agent (E) has an imidazole skeleton.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Conventionally, photosensitive resin compositions that can be developed with an alkaline aqueous solution have been used as materials for forming permanent coatings such as solder resists on printed wiring boards by exposure and development. In response to the increasing density of printed wiring boards accompanying the trend toward lighter, thinner, shorter, and smaller electronic devices, miniaturization and increased pin counts of semiconductor packages have been put into practical use and mass production has progressed, and recently, semiconductor packages such as BGA (ball grid array) and CSP (chip scale package) using package substrates have been adopted instead of semiconductor packages called QFP (quad flat package) and SOP (small outline package).

[0003] On the other hand, the miniaturization and high density of the package substrate at the connection portion between the IC chip and the package substrate are progressing, and the solder resist used in the package substrate is also required to have improved resolution. Also, since the connection portion is encapsulated with underfill to improve reliability (for example, Patent Document 1), the solder resist is required to have good properties such as adhesion to the underfill, wettability and spreadability of the underfill, and bleeding resistance.

[0004] Here, as the miniaturization of connections progresses, there is concern that insufficient underfilling will occur. However, if a highly fluid underfill is used to improve filling, there is a risk of the liquid components of the underfill seeping out from the connections, a phenomenon known as bleeding. Since bleeding can cause not only poor appearance but also poor electrical conductivity in the electrodes, improving bleeding resistance is important. Furthermore, high-performance IC chips are larger than ever before, and as a result, improving adhesion has also become more important. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-284851 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, solder resists for package substrates are required to have properties such as good resolution, high adhesion to underfill, good wettability and spreadability of underfill, and bleeding resistance. However, it is not easy to achieve both of these properties, and the amount of inorganic filler in the composition has a large effect. Reducing the amount of inorganic filler can reduce light scattering in the composition, thereby improving resolution. In addition, the resin component in the composition increases relatively, so that the wettability and adhesion of underfill tend to improve. On the other hand, reducing the amount of inorganic filler can cause a decrease in bleeding resistance.

[0007] Therefore, an object of the present invention is to provide a photosensitive resin composition which improves resolution, is less likely to cause underfill bleeding, has sufficient wetting and spreading of the underfill, and gives a cured product with excellent adhesion; a dry film having a resin layer obtained from the composition; a cured product of the composition or the resin layer of the dry film; and an electronic component having the cured product. [Means for solving the problem]

[0008] As a result of intensive research to solve the above problems, the present inventors have found that by setting the amount of inorganic filler to less than 35 mass% of the total solid content of the photosensitive resin composition and using a silane coupling agent having an imidazole skeleton, it is possible to improve the resolution, suppress the occurrence of bleeding, ensure sufficient wetting and spreading of the underfill, and improve adhesion, thereby completing the present invention. In addition, it has been found that by using it in combination with a specific epoxy resin, the bleeding resistance and adhesion are further improved.

[0009] That is, the photosensitive resin composition of the present invention is (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a silane coupling agent; The blending amount of the (D) inorganic filler is less than 35 mass% of the total solid content, The (E) silane coupling agent is characterized by having an imidazole skeleton.

[0010] In the photosensitive resin composition of the present invention, the epoxy resin (B) is preferably a crystalline epoxy resin having a melting point of 60 to 120°C.

[0011] In the photosensitive resin composition of the present invention, the blending amount of the (E) silane coupling agent is preferably 0.1 to 20 mass % based on the total solid content.

[0012] In the photosensitive resin composition of the present invention, the (E) silane coupling agent preferably has no secondary hydroxyl group.

[0013] In the photosensitive resin composition of the present invention, the (E) silane coupling agent preferably has a structure represented by the following formula (1). TIFF0007652608000001.tif33153 (in the formula, R 1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R 2 represents a hydrogen atom, a vinyl group, or an alkyl group having 1 to 5 carbon atoms; R 3 represents an alkyl group having 1 to 3 carbon atoms, and R 4 represents an alkyl group having 1 to 3 carbon atoms, and n represents an integer of 1 to 3.

[0014] The dry film of the present invention is characterized by having a resin layer obtained by applying the above-mentioned photosensitive resin composition to a film and drying it.

[0015] The cured product of the present invention is characterized by being obtained by curing the photosensitive resin composition or the resin layer of the dry film.

[0016] The electronic part of the present invention is characterized by having the above-mentioned cured product. Effect of the Invention

[0017] According to the present invention, it is possible to provide a photosensitive resin composition which improves resolution, is less likely to cause underfill bleeding, has sufficient wet-spreading of the underfill, and gives a cured product with excellent adhesion; a dry film having a resin layer obtained from the composition; a cured product of the composition or the resin layer of the dry film; and an electronic component having the cured product. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The photosensitive resin composition of the present invention includes (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a silane coupling agent, and is characterized in that the blending amount of the inorganic filler (D) is less than 35 mass% of the total solid content, and the silane coupling agent (E) has an imidazole skeleton. When the inorganic filler is less than 35 mass%, the wettability of the underfill and the solder resist is improved, thereby improving adhesion. On the other hand, it is thought that bleeding is more likely to occur due to the improved wettability, but by adding imidazole silane, the polarity of the resin component can be controlled and bleeding can be suppressed. In addition, by focusing on a crystalline epoxy resin that is solid at a temperature below its melting point due to the regular arrangement of polymer chains, but has a low viscosity comparable to that of a liquid resin when melted, the bleeding resistance and adhesion can be further improved by using an epoxy resin with a melting point of 60°C to 120°C and high crystallinity.

[0019] Each component of the photosensitive resin composition of the present invention will be described below.

[0020] [(A) Carboxyl group-containing resin] As the (A) carboxyl group-containing resin, various conventionally known carboxyl group-containing resins having a carboxyl group in the molecule can be used. In particular, a carboxyl group-containing photosensitive resin having an ethylenically unsaturated double bond in the molecule is preferred from the viewpoint of photocurability and development resistance. The ethylenically unsaturated double bond is preferably derived from acrylic acid or methacrylic acid or a derivative thereof. When using only a carboxyl group-containing resin having no ethylenically unsaturated double bond, it is necessary to use a compound having a plurality of ethylenically unsaturated groups in the molecule, i.e., a photoreactive monomer, which will be described later, in combination in order to make the composition photocurable. The (A) carboxyl group-containing resin may be used alone or in combination of two or more kinds. Specific examples of the carboxyl group-containing resin include the following compounds (which may be either oligomers or polymers):

[0021] (1) Carboxyl group-containing resins obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth)acrylate, isobutylene, etc.

[0022] (2) Carboxyl group-containing urethane resins obtained by the polyaddition reaction of diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates with carboxyl group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, and diol compounds such as polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

[0023] (3) Terminal carboxyl group-containing urethane resins obtained by reacting acid anhydrides with the terminals of urethane resins obtained by polyaddition reaction of diisocyanate compounds such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates with diol compounds such as polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

[0024] (4) Carboxyl group-containing urethane resins obtained by polyaddition reaction of diisocyanates with (meth)acrylates of bifunctional epoxy resins such as bisphenol A type epoxy resins, hydrogenated bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bixylenol type epoxy resins, and biphenol type epoxy resins, or their partial acid anhydride modified products, carboxyl group-containing dialcohol compounds, and diol compounds.

[0025] (5) A carboxyl group-containing urethane resin obtained by adding a compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule, such as a hydroxyalkyl (meth)acrylate, during the synthesis of the resin (2) or (4) above, to obtain a terminal (meth)acrylated carboxyl group-containing urethane resin.

[0026] (6) A carboxyl group-containing urethane resin having terminal (meth)acrylation obtained by adding a compound having one isocyanate group and one or more (meth)acryloyl groups in the molecule, such as an equimolar reactant of isophorone diisocyanate and pentaerythritol triacrylate, during the synthesis of the resin (2) or (4) above.

[0027] (7) Carboxyl group-containing resins obtained by reacting a multifunctional epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the hydroxyl groups present in the side chains.

[0028] (8) A carboxyl group-containing resin obtained by reacting a multifunctional epoxy resin with the hydroxyl groups of a difunctional epoxy resin further epoxidized with epichlorohydrin, with (meth)acrylic acid, and adding a dibasic acid anhydride to the resulting hydroxyl groups.

[0029] (9) A carboxyl group-containing polyester resin obtained by reacting a polyfunctional oxetane resin with a dicarboxylic acid and adding a dibasic acid anhydride to the resulting primary hydroxyl group.

[0030] (10) A carboxyl group-containing resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide, reacting the reaction product obtained with an unsaturated group-containing monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride.

[0031] (11) A carboxyl group-containing resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate, reacting the reaction product obtained with an unsaturated group-containing monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride.

[0032] (12) A carboxyl group-containing resin obtained by reacting an epoxy compound having multiple epoxy groups in one molecule with a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, such as p-hydroxyphenethyl alcohol, and an unsaturated group-containing monocarboxylic acid, such as (meth)acrylic acid, and then reacting the alcoholic hydroxyl group of the resulting reaction product with a polybasic acid anhydride, such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic anhydride, or the like.

[0033] (13) A carboxyl group-containing resin having at least one of an amide structure and an imide structure. (14) A carboxyl group-containing photosensitive resin having a copolymer structure, which is obtained by adding a compound having one epoxy group and one or more (meth)acryloyl groups in the molecule, such as glycidyl (meth)acrylate, α-methylglycidyl (meth)acrylate, epoxycyclohexylmethyl (meth)acrylate, etc., to a carboxyl group-containing copolymer resin having monomers of maleimide or a maleimide derivative, such as N-phenylmaleimide or N-benzylmaleimide, an unsaturated carboxylic acid, such as (meth)acrylic acid, an unsaturated group-containing compound having a hydroxyl group, such as hydroxyalkyl (meth)acrylate, and an unsaturated group-containing compound having an aromatic ring, such as styrene, α-methylstyrene, α-chlorostyrene, vinyltoluene, etc.

[0034] (15) A carboxyl group-containing 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, α-methylglycidyl (meth)acrylate, to the carboxyl group-containing resin described in the above (1) to (13), etc. In this specification, (meth)acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

[0035] The (A) carboxyl group-containing resin is not limited to those listed above, and one type may be used alone, or a mixture of two or more types may be used. Among the above carboxyl group-containing resins, the carboxyl group-containing resins (7), (8), and (10) are preferred.

[0036] The acid value of the (A) carboxyl group-containing resin is preferably 20 to 200 mgKOH / g. When the (A) carboxyl group-containing resin has an acid value of 20 to 200 mgKOH / g, it becomes easy to form a pattern of the cured product. The acid value of the (A) carboxyl group-containing resin is more preferably 50 to 130 mgKOH / g.

[0037] The weight average molecular weight of the (A) carboxyl group-containing resin varies depending on the resin skeleton, but is generally preferably in the range of 1,000 to 150,000, more preferably 2,000 to 20,000. If the weight average molecular weight is 1,000 or more, the development resistance of the coating film in the exposed area is improved, and the resolution is excellent. On the other hand, if the weight average molecular weight is 150,000 or less, the solubility of the unexposed area is good, the resolution is excellent, and the storage stability may also be improved. The weight average molecular weight can be measured by gel permeation chromatography.

[0038] The amount of the (A) carboxyl group-containing resin is 10 to 70% by mass based on the total solid content of the photosensitive resin composition. By making it 10% by mass or more, the coating strength can be improved. On the other hand, by making it 70% by mass or less, the viscosity becomes appropriate and the processability is improved.

[0039] [(B) Epoxy resin] The photosensitive resin composition of the present invention contains (B) an epoxy resin.

[0040] (B) Epoxy resins include bisphenol A type epoxy resins; hydroquinone type epoxy resins; bisphenol type epoxy resins; thioether type epoxy resins; brominated epoxy resins; novolac type epoxy resins; biphenol novolac type epoxy resins; bisphenol F type epoxy resins; hydrogenated bisphenol A type epoxy resins; glycidylamine type epoxy resins; hydantoin type epoxy resins; alicyclic epoxy resins; trihydroxyphenylmethane type epoxy resins; alkylphenol type epoxy resins (e.g., bixylenol type epoxy resins); biphenol type epoxy resins; bisphenol S epoxy resins; bisphenol A novolac type epoxy resins; tetraphenylolethane type epoxy resins; heterocyclic epoxy resins; diglycidyl phthalate resins; tetraglycidyl xylenoylethane resins; naphthalene group-containing epoxy resins; epoxy resins having a dicyclopentadiene skeleton; triphenylmethane type epoxy resins; epoxy resins having a silsesquioxane skeleton; glycidyl methacrylate copolymer epoxy resins; cyclohexylmaleimide and glycidyl methacrylate copolymer epoxy resins; epoxy-modified polybutadiene rubber derivatives; CTBN-modified epoxy resins, etc. (B) The epoxy resins can be used alone or in combination of two or more.

[0041] From the viewpoint of improving bleeding resistance and adhesion, the epoxy resin (B) is preferably a crystalline epoxy resin having a melting point of 60 to 120° C. These epoxy resins exist in a solid state at temperatures below their melting points, and become a low-viscosity liquid at temperatures above their melting points. Furthermore, when the melting point is 60° C. or higher, it is difficult for the resin to be eluted during development, and when it is 120° C. or lower, it has excellent lamination properties.

[0042] The structure of the crystalline epoxy resin having a melting point of 60 to 120° C. is not particularly limited, but specific examples include crystalline bifunctional epoxy resins having a biphenyl structure, a sulfide structure, a phenylene structure, a naphthalene structure, etc. Among them, those having the following general formula: TIFF0007652608000002.tif26153 (in the formula, R 5 , R 6 , R7 and R 8 each independently represents a hydrogen atom or a methyl group) can be suitably used. Commercially available crystalline epoxy resins having a melting point of 60 to 120°C include YX-4000, YX-4000H, and YL-6121HA manufactured by Mitsubishi Chemical Corporation, and YSLV-70XY and YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.

[0043] The melting point of the crystalline epoxy resin may be in the range of 60 to 120°C, and is preferably 70 to 110°C.

[0044] The blending amount of the (B) epoxy resin is preferably 5 to 80 mass % based on the total solid content of the photosensitive resin composition.

[0045] In the photosensitive resin composition of the present invention, when the crystalline epoxy resin is used in combination with another epoxy resin, the crystalline epoxy resin is preferably contained in an amount of 20 mass % or more, and more preferably 35 to 100 mass %, based on the total amount of the epoxy resin (B) in terms of solid content.

[0046] In addition, the photosensitive resin composition of the present invention may contain a thermosetting resin other than an epoxy resin, as long as the effects of the present invention are not impaired. Known and commonly used thermosetting resins such as an isocyanate compound, a blocked isocyanate compound, an amino resin, a benzoxazine resin, a carbodiimide resin, a cyclocarbonate compound, a polyfunctional oxetane compound, and an episulfide resin can be used.

[0047] [(C) Photopolymerization initiator] The photosensitive resin composition of the present invention contains a photopolymerization initiator (C). As the photopolymerization initiator (C), any photopolymerization initiator known as a photopolymerization initiator or a photoradical generator can be used, and examples thereof 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, and bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (IGM Bisacylphosphine oxides such as Omnirad 819 (manufactured by Resins); 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphine acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphine acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (IGM Monoacylphosphine oxides such as Omnirad TPO (manufactured by Resins); hydroxyacetophenones such as 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, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoins such as benzoin, benzil, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; benzoin alkyl ethers;Benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone and other benzophenones; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2 -Dimethylamino-1-(4-morpholinophenyl)-butanone-1, 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; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, and p-dimethylbenzoic acid ethyl ester; 1,2-octanedione, 1-[4 -(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) 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-pyr-1-yl)ethyl)phenyl]titanium and other titanocenes;Examples of the photopolymerization initiator include phenyl disulfide 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, and tetramethylthiuram disulfide. (C) The photopolymerization initiator may be used alone or in combination of two or more. Among them, monoacylphosphine oxides and oxime esters are preferred, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) are more preferred.

[0048] The amount of the photopolymerization initiator (C) is preferably 0.05 to 20 mass % based on the total solid content of the photosensitive resin composition, and more preferably 0.1 to 5 mass %. By using the amount above, the photocurability on copper is more reliable, the coating properties such as chemical resistance are improved, halation is less likely to occur, and the resolution is better.

[0049] [(D) Inorganic filler] The photosensitive resin composition of the present invention contains (D) an inorganic filler. The amount of the (D) inorganic filler is less than 35 mass% of the total solid content of the composition. The (D) inorganic filler is not particularly limited, and known and commonly used inorganic fillers such as silica, such as amorphous silica, crystalline silica, fused silica, and spherical silica, Neuburg silica, aluminum hydroxide, glass powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, aluminum oxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, mineral wool, aluminum silicate, calcium silicate, and zinc oxide can be used. It is preferable that the (D) inorganic filler contains silica. Examples of silica include fused silica, spherical silica, amorphous silica, and crystalline silica, and spherical silica is preferable.

[0050] (D) The inorganic filler is preferably a surface-treated inorganic filler, and more preferably, the surface of the inorganic filler is subjected to a surface treatment capable of introducing a curable reactive group. Here, the curable reactive group is not particularly limited as long as it is a group that undergoes a curing reaction with a curable compound such as (A) an alkali-soluble resin such as a carboxyl group-containing resin or (B) a thermosetting resin such as an epoxy resin, and may be a photocurable reactive group or a thermosetting reactive group. Examples of the photocurable reactive group include a methacryl group, an acrylic group, a vinyl group, and a styryl group, and examples of the thermosetting reactive group 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, and an oxazoline group. The method of introducing a curable reactive group into the surface of the inorganic filler is not particularly limited, and may be introduced using a known, commonly used method. The surface of the inorganic filler may be treated with a surface treatment agent having a curable reactive group, for example, a coupling agent having a curable reactive group as an organic group. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent, etc. may be used. In addition, examples of surface-treated inorganic fillers that do not have a curable reactive group include inorganic fillers that have been subjected to silica-alumina surface treatment, titanate-based coupling agent treatment, aluminate-based coupling agent treatment, fluorene-based coupling agent treatment, and organic treatment. In addition, the inorganic filler may be coated with a hydrated oxide of silicon, a hydrated oxide of aluminum, a hydrated oxide of zirconium, a hydrated oxide of zinc, a hydrated oxide of titanium, etc. as a surface treatment.

[0051] The average particle size of the inorganic filler (D) is preferably 0.01 to 0.8 μm. Here, in this specification, the average particle size of the inorganic filler is the average particle size (D50) including not only the particle size of the primary particles but also the particle size of the secondary particles (aggregates), and can be determined by a laser diffraction particle size distribution measuring device and a measuring device using a dynamic light scattering method. For example, as a measuring device using the laser diffraction method, Microtrac MT3300EXII (measurement range: 0.02 to 2,000 μm) manufactured by Microtrac-Bell may be used, and if the measurement range is below, Nanotrac Wave II UT151 (measurement range: 0.8 to 6,500 nm) manufactured by Microtrac-Bell may be used as a measuring device using the dynamic light scattering method.

[0052] The inorganic filler (D) may have an average particle size adjusted, and is preferably pre-dispersed, for example, by a bead mill or a jet mill. The inorganic filler is preferably blended in a slurry state, which facilitates high dispersion, prevents aggregation, and makes handling easier.

[0053] The (D) inorganic filler may be used alone or in combination of two or more. The blending amount of the (D) inorganic filler is preferably 5% by mass or more and less than 35% by mass, more preferably 15 to 34% by mass, based on the total solid content of the photosensitive resin composition. By making it 5% by mass or more, the strength and rigidity of the cured product can be improved. By making it less than 35% by mass, the wettability of the cured product and the underfill material is improved, and the adhesion is improved. When silica and another inorganic filler are used in combination in the (D) inorganic filler, the silica is preferably contained in an amount of 30% by mass or more, more preferably 40 to 100% by mass, based on the total amount of the (D) inorganic filler, calculated as solid content.

[0054] [(E) Silane coupling agent having an imidazole skeleton] The photosensitive resin composition of the present invention contains (E) a silane coupling agent having an imidazole skeleton (hereinafter also abbreviated as "(E) silane coupling agent"). The (E) silane coupling agent is not particularly limited as long as it is a silane coupling agent having an imidazole ring, and examples of the silane coupling agent having an imidazole ring and an alkoxysilyl group include silane coupling agents represented by the following formula (1) or (2).

[0055] TIFF0007652608000003.tif33153TIFF0007652608000004.tif36153(In equations (1) and (2), R 1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R 2 represents a hydrogen atom, a vinyl group, or an alkyl group having 1 to 5 carbon atoms; R 3 represents an alkyl group having 1 to 3 carbon atoms, and R 4 represents an alkyl group having 1 to 3 carbon atoms, and n represents an integer of 1 to 3.

[0056] In formulas (1) and (2), R 1 R is preferably a hydrogen atom, a methyl group, an ethyl group, an undecyl group, or a heptadecyl group. 2 is preferably a hydrogen atom or a methyl group. 3 is preferably a methyl group or an ethyl group. 4 is preferably a methyl group or an ethyl group. Specifically, silane coupling agents represented by formula (3) and formula (4) are preferred. TIFF0007652608000005.tif38153 TIFF0007652608000006.tif29153

[0057] From the viewpoints of bleed resistance and ink viscosity, it is preferable that the (E) silane coupling agent does not have a secondary hydroxyl group, and it is more preferable that it is a silane coupling agent represented by the above formula (1), and specifically, it is preferable that it is a silane coupling agent represented by the above formula (3).

[0058] The (E) silane coupling agent may be used alone or in combination of two or more. The blending amount of the (E) silane coupling agent is preferably 0.1 to 20 mass% of the total solid content of the photosensitive resin composition. When it is 0.1 to 20 mass%, the balance of bleeding resistance, adhesion, and ink viscosity is excellent. It is more preferably 1 to 15 mass%, and further preferably 1.5 to 11 mass%.

[0059] (Compound having an ethylenically unsaturated group) The photosensitive resin composition of the present invention may contain a compound having an ethylenically unsaturated group, such as a photopolymerizable oligomer or a photopolymerizable vinyl monomer.

[0060] Examples of the photopolymerizable oligomer include unsaturated polyester oligomers, (meth)acrylate oligomers, etc. Examples of the (meth)acrylate oligomer include epoxy (meth)acrylates such as phenol novolac epoxy (meth)acrylate, cresol novolac epoxy (meth)acrylate, and bisphenol type epoxy (meth)acrylate, urethane (meth)acrylate, epoxy urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, and polybutadiene modified (meth)acrylate.

[0061] Examples of the photopolymerizable vinyl monomer include known and commonly used ones, for example, styrene derivatives such as styrene, chlorostyrene, and α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate, and vinyl benzoate; vinyl ethers such as vinyl isobutyl ether, vinyl-n-butyl ether, vinyl-t-butyl ether, vinyl-n-amyl ether, vinyl isoamyl ether, vinyl-n-octadecyl ether, vinyl cyclohexyl ether, ethylene glycol monobutyl vinyl ether, and triethylene glycol monomethyl vinyl ether; (meth)acrylamides such as acrylamide, methacrylamide, N-hydroxymethyl acrylamide, N-hydroxymethyl methacrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, and N-butoxymethyl acrylamide; allyl compounds such as triallyl isocyanurate, diallyl phthalate, and diallyl isophthalate; 2-ethylhexyl (meth)acrylate, lauryl ( (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate and other (meth)acrylic acid esters; hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate and other hydroxyalkyl (meth)acrylates; methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate and other alkoxyalkylene glycol mono(meth)acrylates; ethylene glycol di(meth)acrylate, butanediol di(meth)acrylates, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate and other alkylene polyol poly(meth)acrylates;Examples of the polyoxyalkylene glycol poly(meth)acrylates include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane tri(meth)acrylate; poly(meth)acrylates such as hydroxypivalic acid neopentyl glycol ester di(meth)acrylate; and isocyanurate-type poly(meth)acrylates such as tris[(meth)acryloxyethyl]isocyanurate. These may be used alone or in combination of two or more types according to the required properties.

[0062] The amount of the compound having an ethylenically unsaturated group is preferably 0.2 to 60 mass%, more preferably 0.2 to 50 mass%, based on the total solid content of the photosensitive resin composition. By making the amount of the compound having an ethylenically unsaturated group 0.2 mass% or more, the photocurability of the photosensitive resin composition is improved. In addition, by making the amount 60 mass% or less, the coating hardness can be improved.

[0063] (Cure accelerator) The photosensitive resin composition of the present invention may contain a curing accelerator. Examples of the curing accelerator include imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzylamine, and 4-dimethylaminopyridine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Also usable are S-triazine derivatives such as guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine·isocyanuric acid adduct, and 2,4-diamino-6-methacryloyloxyethyl-S-triazine·isocyanuric acid adduct. The curing accelerator may be used alone or in combination of two or more.

[0064] The amount of the curing accelerator to be added is preferably 0.01 to 30% by mass based on the total amount of solids in the photosensitive resin composition.

[0065] (Elastomer) The photosensitive resin composition of the present invention preferably contains an elastomer. By containing an elastomer, the modulus of elasticity can be reduced, so that stress during curing can be alleviated and crack resistance can be further improved. As the elastomer, a known elastomer can be used, for example, a polyester-based elastomer, a styrene-based elastomer, a polyurethane-based elastomer, a polyester urethane-based elastomer, a polyamide-based elastomer, a polyester amide-based elastomer, an acrylic-based elastomer, an olefin-based elastomer, a silicone-based elastomer, etc. can be used. In addition, resins in which a part or all of the epoxy groups of epoxy resins having various skeletons are modified with both-end carboxylic acid-modified butadiene-acrylonitrile rubber can also be used. Furthermore, epoxy-containing polybutadiene-based elastomers, acrylic-containing polybutadiene-based elastomers, hydroxyl-containing polybutadiene-based elastomers, hydroxyl-containing isoprene-based elastomers, block copolymers, etc. can also be used. For example, trade names include R-45HT, Polybd HTP-9 (both manufactured by Idemitsu Kosan Co., Ltd.), Epolead PB3600 (manufactured by Daicel Chemical Industries, Ltd.), Denalex R-45EPT (manufactured by Nagase ChemteX Corporation), Tafthren (manufactured by Sumitomo Chemical Co., Ltd.), Ricon series such as Ricon 130 (manufactured by Cray Valley Corporation), Hytrel (manufactured by DuPont-Toray Co., Ltd.), Pelprene (manufactured by Toyobo Co., Ltd.), Espel 1612, 1620 (manufactured by Hitachi Chemical Co., Ltd.), etc. These elastomers can be used alone or in combination of two or more types.

[0066] The amount of the elastomer is preferably 0.5 to 10% by mass based on the total solid content of the photosensitive resin composition.

[0067] (Coloring agent) The photosensitive resin composition of the present invention may contain a colorant. The colorant may be used alone or in combination of two or more. As the colorant, known colorants such as red, blue, green, yellow, black, and white may be used, and may be any of pigments, dyes, and colorants. However, from the viewpoint of reducing the environmental load and the effect on the human body, it is preferable that the colorant does not contain halogen.

[0068] The amount of the colorant to be added is preferably 0.01 to 10% by mass based on the total solid content of the photosensitive resin composition.

[0069] (Organic solvent) The photosensitive resin composition of the present invention may contain an organic solvent for the purpose of adjusting the viscosity when preparing the composition or when applying it to a substrate or a carrier film. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha. Known and commonly used organic solvents can be used. The organic solvents can be used alone or in combination of two or more.

[0070] (Other optional ingredients) Furthermore, the photosensitive resin composition of the present invention may contain other additives that are well known and commonly used in the field of electronic materials, such as a thermal polymerization inhibitor, an ultraviolet absorber, a silane coupling agent other than the (E) silane coupling agent, a plasticizer, a flame retardant, an antistatic agent, an antiaging agent, an antibacterial and antifungal agent, an antifoaming agent, a leveling agent, a thickener, an adhesion imparting agent, a thixotropy imparting agent, a photoinitiator assistant, a sensitizer, a thermoplastic resin, an organic filler, a release agent, a surface treatment agent, a dispersant, a dispersion assistant, a surface modifier, a stabilizer, and a phosphor.

[0071] The photosensitive resin composition of the present invention may be used in the form of a dry film or in the form of a liquid. When used in the form of a liquid, it may be a one-component type or a two-component or more type.

[0072] Next, the dry film of the present invention has a resin layer obtained by applying and drying the photosensitive resin composition of the present invention on a carrier film. When forming a dry film, first, the photosensitive resin composition of the present invention is diluted with the above organic solvent to adjust the viscosity to an appropriate level, and then coated on the carrier film to a uniform thickness using a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, gravure coater, spray coater, or the like. Thereafter, the applied composition is usually dried at a temperature of 40 to 130° C. for 1 to 30 minutes to form a resin layer. There is no particular restriction on the coating thickness, but it is generally appropriately selected within the range of 3 to 150 μm, preferably 5 to 60 μm, in terms of the film thickness after drying.

[0073] As the carrier film, a plastic film is used, and 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 restriction on the thickness of the carrier film, but it is generally appropriately selected in the range of 10 to 150 μm. It is more preferably in the range of 15 to 130 μm.

[0074] After forming a resin layer made of the photosensitive resin composition of the present invention on the carrier film, it is preferable to further laminate a peelable cover film on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. For example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, etc. can be used as the peelable cover film. The cover film may be any film that has a smaller adhesive force than that between the resin layer and the carrier film when the cover film is peeled off.

[0075] In the present invention, the photosensitive resin composition of the present invention may be applied to the cover film and dried to form a resin layer, and a carrier film may be laminated on the surface of the resin layer. That is, in the present invention, either a carrier film or a cover film may be used as the film to which the photosensitive resin composition of the present invention is applied when producing a dry film.

[0076] The electronic component of the present invention has a cured product obtained from the resin layer of the photosensitive resin composition or dry film of the present invention. As an example of a method for producing an electronic component of the present invention, a method for producing a printed wiring board is, for example, to adjust the viscosity of the photosensitive resin composition of the present invention to a suitable viscosity for the coating method using the organic solvent, and apply the composition to a substrate by a method such as dip coating, flow coating, roll coating, bar coating, screen printing, or curtain coating, and then evaporate and dry (temporarily dry) the organic solvent contained in the composition at a temperature of 60 to 100 ° C. to form a tack-free resin layer. In addition, in the case of a dry film, the resin layer is attached to the substrate by a laminator or the like so that the resin layer contacts the substrate, and then the carrier film is peeled off to form a resin layer on the substrate.

[0077] The above-mentioned substrates include printed wiring boards and flexible printed wiring boards on which circuits have been formed in advance using copper or the like, as well as materials such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, copper-clad laminates for high-frequency circuits made from fluororesin, polyethylene, polyphenylene ether, polyphenylene oxide, cyanate, etc., including copper-clad laminates of all grades (FR-4, etc.), as well as metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates, etc.

[0078] The volatilization drying carried out after coating of the photosensitive resin composition of the present invention can be carried out using a hot air circulation drying oven, an IR oven, a hot plate, a convection oven, or the like (a method in which hot air in a dryer equipped with a heat source of an air heating method using steam is brought into countercurrent contact with the substrate, or a method in which hot air is blown onto the substrate from a nozzle).

[0079] After forming a resin layer on a printed wiring board, the resin layer is selectively exposed to active energy rays through a photomask with a predetermined pattern formed thereon, and the unexposed areas are developed with a dilute alkaline aqueous solution (e.g., 0.3 to 3 mass% aqueous sodium carbonate solution) to form a pattern of a cured product. The cured product is then irradiated with active energy rays and then heat-cured (e.g., 100 to 220°C), or is irradiated with active energy rays after heat-curing, or is heat-cured only to form a final finish curing (main curing) to form a cured film with excellent properties such as adhesion and hardness. When the photosensitive resin composition of the present invention contains a photobase generator, it is preferable to heat the composition after exposure and before development. The heating conditions after exposure and before development are preferably, for example, heating at 60 to 150° C. for 1 to 60 minutes.

[0080] The exposure machine used for the above-mentioned active energy ray irradiation may be a machine equipped with a high pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, or the like, and capable of irradiating ultraviolet rays in the range of 350 to 450 nm. Furthermore, a direct imaging machine (for example, a laser direct imaging machine that directly draws an image with a laser based on CAD data from a computer) may also be used. The lamp light source or laser light source of the direct imaging machine may have a maximum wavelength in the range of 350 to 450 nm. The exposure dose for forming an image varies depending on the film thickness, etc., but is generally 10 to 1000 mJ / cm. 2 , preferably 20 to 800 mJ / cm 2 The range may be:

[0081] The developing method can be a dipping method, a shower method, a spray method, a brush method, or the like, and the developing solution can be an aqueous alkali solution of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, or the like.

[0082] The photosensitive resin composition of the present invention is preferably used to form a cured film on an electronic component, particularly a cured film on a printed wiring board, more preferably used to form a permanent coating, and even more preferably used to form a solder resist. Furthermore, according to the photosensitive resin composition of the present invention, even when a highly fluid underfill is used, bleeding of the underfill is unlikely to occur, and a cured product having excellent adhesion to the underfill can be obtained, so that the composition can be preferably used to form, for example, a permanent coating (particularly a solder resist) for a package substrate, particularly FC-BGA. EXAMPLES

[0083] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples. In the following, "parts" and "%" are all based on mass unless otherwise specified.

[0084] [Synthesis of carboxyl group-containing resin] (Carboxyl group-containing resin A-1) To 600 g of diethylene glycol monoethyl ether acetate, 1,070 g (number of glycidyl groups (total number of aromatic rings): 5.0 mol) of orthocresol novolac epoxy resin (EPICLON N-695 manufactured by DIC Corporation, softening point 95°C, epoxy equivalent 214, average number of functional groups 7.6), 360 g (5.0 mol) of acrylic acid, and 1.5 g of hydroquinone were added, and the mixture was heated to 100°C with stirring to dissolve uniformly. Next, 4.3g of triphenylphosphine was added, heated to 110°C and reacted for 2 hours, then heated to 120°C and reacted for another 12 hours. 415g of aromatic hydrocarbon (Solvesso 150) and 456.0g (3.0 moles) of tetrahydrophthalic anhydride were added to the resulting reaction solution, reacted at 110°C for 4 hours, and cooled to obtain a solution of photosensitive carboxyl group-containing resin A-1. The solid content of the resin solution thus obtained was 65%, and the acid value of the solid content was 89mgKOH / g. Hereinafter, this solution of carboxyl group-containing photosensitive resin is referred to as resin solution A-1.

[0085] (Carboxyl group-containing resin A-2) Into an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device, and a stirrer, 119.4 parts of novolac cresol resin (Aica Kogyo Co., Ltd., Shounol CRG-951 OH equivalent: 119.4), 1.19 parts of potassium hydroxide, and 119.4 parts of toluene were introduced, and the system was replaced with nitrogen while stirring, and heated to increase the temperature. Next, 63.8 parts of propylene oxide were gradually added dropwise, and the temperature was increased to 125-132°C and 0-4.8 kg / cm. 2 The mixture was reacted at 40° C. for 16 hours. After that, it was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to the reaction solution to neutralize the potassium hydroxide, to obtain a propylene oxide reaction solution of novolak cresol resin with a solid content of 62.1% and a hydroxyl value of 182.2 mgKOH / g (307.9 g / eq.). This was an average of 1.08 moles of propylene oxide added per equivalent of phenolic hydroxyl group. 293.0 parts of the propylene oxide reaction solution of the obtained novolac cresol resin, 43.2 parts of acrylic acid, 11.53 parts of methanesulfonic acid, 0.18 parts of methylhydroquinone, and 252.9 parts of toluene were introduced into a reactor equipped with a stirrer, a thermometer, and an air inlet tube, and the mixture was reacted at 110°C for 12 hours while blowing air at a rate of 10 ml / min and stirring. The water produced by the reaction was distilled as an azeotrope with toluene, and 12.6 parts of water were distilled. After that, the mixture was cooled to room temperature, and the obtained reaction solution was neutralized with 35.35 parts of 15% aqueous sodium hydroxide solution, and then washed with water. After that, the toluene was distilled off while replacing it with 118.1 parts of diethylene glycol monoethyl ether acetate in an evaporator, and a novolac acrylate resin solution was obtained. Next, 332.5 parts of the obtained novolac-type acrylate resin solution and 1.22 parts of triphenylphosphine were introduced into a reactor equipped with a stirrer, a thermometer, and an air inlet tube, and 60.8 parts of tetrahydrophthalic anhydride were gradually added while blowing air at a rate of 10 ml / min and stirring, and the mixture was reacted at 95 to 101°C for 6 hours, cooled, and then removed. In this way, a solution of photosensitive carboxyl group-containing resin A-2 with a solid content of 65% and an acid value of the solid content of 87.7 mgKOH / g was obtained. Hereinafter, this solution of carboxyl group-containing photosensitive resin is referred to as resin solution A-2.

[0086] [Preparation of filler] (Preparation of Silica Slurry) 70 g of spherical silica particles (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm), 28 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) were uniformly dispersed to obtain a silica slurry surface-treated with methacrylsilane.

[0087] (Preparation of Barium Sulfate Slurry) 70 g of barium sulfate particles (B-30 manufactured by Sakai Chemical Industry Co., Ltd.), 28 g of CA (carbitol acetate) as a solvent, and 2 g of a dispersant (DISPERBYK-111 manufactured by BYK-Chemie Co., Ltd.) were uniformly dispersed to obtain a barium sulfate slurry.

[0088] [Example 1~ 5 , Reference Example 6: Comparative Examples 1-2 The resin solution (varnish) and various components shown in Table 1 were mixed in the ratios (parts by mass) shown in Table 1, diluted with an organic solvent to a viscosity suitable for dispersion in a bead mill, premixed in a stirrer, and then kneaded in a bead mill to disperse the photosensitive resin composition. The resulting dispersion was passed through a filter with a mesh size of 10 μm to obtain a photosensitive resin composition.

[0089] <Preparation of dry film> The photosensitive resin composition obtained as above was diluted with 300 g of methyl ethyl ketone, and the mixture was stirred with a stirrer for 15 minutes to obtain a coating liquid. The coating liquid was applied onto a polyethylene terephthalate film (carrier film: T100 manufactured by Mitsubishi Chemical Corporation) having a thickness of 25 μm, and typically dried at a temperature of 80° C. for 15 minutes to form a resin layer having a thickness of 20 μm. Next, a biaxially oriented polypropylene film (cover film: OPP-FOA manufactured by Futamura Corporation) was laminated onto the resin layer to produce a dry film.

[0090] <Creating an evaluation board> The dry film was heat-laminated onto a BT substrate using a vacuum laminator. The entire surface of the resulting laminate was exposed to light, the PET film was peeled off, and then a 1% by mass Na2CO3 aqueous solution at 30°C was sprayed at a pressure of 2 kg / cm. 2 After development, the film was transferred to a UV conveyor with an integrated light dose of 1000 mJ / cm 2 The resist was then irradiated with light at 1000 rpm and heat cured in a drying oven at 160° C. for 60 minutes to form a resist film, thereby obtaining an evaluation substrate.

[0091] <Evaluation of bleeding resistance> The obtained evaluation board was treated with plasma (gas: O2, output: 300 W, vacuum: 200 mTorr), after which 0.2 g of underfill was dropped and cured at 165°C for 2 hours. The bleeding area was measured using a digital microscope (VHX-6000, manufactured by KEYENCE). U8410-302 (manufactured by Namics) was used as the underfill, and evaluation was performed based on the average value of n=6. ◎: Bleed amount is 500μm or less. ○: Bleed amount is more than 500 μm and less than 600 μm. △: Bleed amount is more than 600 μm and 700 μm or less. ×: Bleed amount is more than 700 μm.

[0092] <Evaluation of underfill adhesion> The obtained evaluation board was treated with plasma (gas: O2, output: 300 W, vacuum: 200 mTorr). 0.2 g of underfill was dropped onto it, and a 5 mm square silicon chip that had been previously plasma-treated (gas: O2, output: 600 W, vacuum: 100 mTorr) was placed on top and cured at 165°C for 2 hours. A die shear test was performed at room temperature at 500 μm / s using a bond tester (4000 Plus / Optima Nordson). ◎: No peeling occurs between the underfill and solder resist, and the shear strength is 100N or more. ◯: No peeling occurs between the underfill and the solder resist, and the shear strength is 80N or more and less than 100N. △: No peeling occurs between the underfill and the solder resist, and the shear strength is weaker than 80N. ×: Peeling occurs between the underfill and the solder resist.

[0093] <Evaluation of Viscosity> The ink viscosity of the photosensitive resin composition prepared above was measured using a cone-plate type viscometer at a temperature of 25° C. The viscosity obtained at a rotation speed of 5 rpm was evaluated as follows. ◎: Viscosity is 40 mPa·s or less. Good: Viscosity is higher than 40 mPa·s and less than 100 mPa·s. ×: Viscosity is higher than 100 mPa·s.

[0094] <Evaluation of resolution> The dry film prepared by the above method was heat laminated on a CZ-treated copper-plated substrate using a vacuum laminator. This substrate was exposed to light using a projection exposure machine through a step tablet (Photec 41 steps), after which the PET film was peeled off and a 1 wt% Na2CO3 aqueous solution at 30°C was sprayed at a pressure of 2 kg / cm. 2 The substrate was then exposed to a UV conveyor oven for 60 seconds at an integrated exposure of 1000 mJ / cm 2 After irradiating with UV light under the above conditions, the film was heat cured at 160°C for 60 minutes. When the resulting cured film showed 8 levels of sensitivity using the step tablet, the openings in the mask design were observed using a SEM to check for the occurrence of halation or undercut and to perform an evaluation. The evaluation criteria are as follows: ◎: Good opening diameter at 50 μm. ×: A good opening diameter was not obtained at 50 μm.

[0095] <Evaluation of Wetting and Spreading Properties> The obtained evaluation board was treated with plasma (gas: O2, output: 300W, vacuum: 200mTorr), after which 0.2g of underfill was dropped and cured at 165℃ for 2 hours. The area of ​​the underfill was measured using a digital microscope (VHX-6000, manufactured by KEYENCE). The underfill was U8410-302 (manufactured by Namics), and evaluation was performed based on the average value of n=6. ◎: Underfill area is 1500mm 2 The end. ×: Underfill area is 1500mm 2 less than.

[0096] [Table 1]

[0097] A-1: Solution of the carboxyl group-containing resin A-1 synthesized above A-2: Solution of the carboxyl group-containing resin A-2 synthesized above *1: BASF Japan Irgacure OXE02 (photopolymerization initiator, photobase generator (ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime)) *2: IGM Resins Omnirad TPO (photopolymerization initiator (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide)) *3: Mitsubishi Chemical YX-4000 (biphenyl type epoxy resin having the structure shown in the above general formula (crystalline epoxy resin with a melting point of 105°C)) *4: DIC N870-75EA (bisphenol A type epoxy resin) *5: Methacrylic surface-treated silica slurry prepared in Preparation 1 of Silica Slurry above *6: Barium slurry prepared in the above method for preparing barium slurry *7: IS-1000 manufactured by JX Metals Trading Co., Ltd. (a silane coupling agent having an imidazole skeleton represented by the following formula) TIFF0007652608000008.tif25153*8: IM-1000 manufactured by JX Metals Trading Co., Ltd. (a silane coupling agent having an imidazole skeleton represented by the following formula) TIFF0007652608000009.tif33153*9: Daicel Epolead PB3600 *10: KAYARAD DPHA (dipentaerythritol hexaacrylate) manufactured by Nippon Kayaku Co., Ltd. *11:DICY (Dicyandiamide)

[0098] From the results shown in the above table, Examples 1 to 5. Reference Example 6 It can be seen that the photosensitive resin composition of the above improves the resolution, is less susceptible to bleeding of the underfill, has sufficient wetting and spreading of the underfill, and gives a cured product with excellent adhesion.

Claims

1. (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a silane coupling agent, The epoxy resin (B) contains 20 mass% or more of a crystalline epoxy resin having a melting point of 60 to 120°C, based on the total amount of the epoxy resin (B), The blending amount of the (D) inorganic filler is less than 35 mass% of the total solid content, The photosensitive resin composition, wherein the (E) silane coupling agent has an imidazole skeleton.

2. 2. The photosensitive resin composition according to claim 1, wherein the blending amount of the silane coupling agent (E) is 0.1 to 20 mass % of the total solid content.

3. 3. The photosensitive resin composition according to claim 1, wherein the silane coupling agent (E) does not have a secondary hydroxyl group.

4. The photosensitive resin composition according to any one of claims 1 to 3, wherein the silane coupling agent (E) has a structure represented by the following formula (1): (In the formula, R １ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ２ represents a hydrogen atom, a vinyl group, or an alkyl group having 1 to 5 carbon atoms; R ３ represents an alkyl group having 1 to 3 carbon atoms, R ４ represents an alkyl group having 1 to 3 carbon atoms, and n represents an integer of 1 to 3.

5. 5. A dry film comprising a resin layer obtained by applying the photosensitive resin composition according to claim 1 to a film and drying the applied resin layer.

6. A cured product obtained by curing the photosensitive resin composition according to any one of claims 1 to 4 or the resin layer of the dry film according to claim 5.

7. An electronic part comprising the cured product according to claim 6.

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