JP2021033114A - Photosensitive resin composition, patterned cured film and production method of the same, photosensitive element, and printed wiring board and production method of the same - Google Patents

Abstract

To provide a photosensitive resin composition that gives a cured product having a low stress and excellent insulation reliability and toughness even when used for forming a permanent mask resist of a thin printed wiring board.SOLUTION: The photosensitive resin composition comprises (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable monomer having an ethylenically unsaturated bond, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a curing agent comprising a melamine compound. The (D) inorganic filler comprises an inorganic filler to be surface-treated with a silane coupling agent having an amino group, and more preferably, the content of the (D) inorganic filler is 30 to 60 mass% of the total solid content in the photosensitive resin composition. The content of the (E) curing agent is 75 to 140 pts.mass per 100 pts.mass of the (A) acid-modified vinyl group-containing epoxy resin.SELECTED DRAWING: None

Description

The present invention relates to an alkali-developable photosensitive resin composition for a protective film of a printed wiring board, and more specifically, for a protective film of a printed wiring board used as a permanent mask resist in the resist field such as a substrate for a semiconductor package. The present invention relates to a photosensitive resin composition, a pattern cured film using the photosensitive resin composition and a method for producing the same, a photosensitive element, and a printed wiring board and a method for producing the same.

In the field of printed wiring boards, a permanent mask resist (protective film) has been conventionally formed on a printed wiring board. As a method for forming a pattern of a photosensitive resist, a colored photosensitive resin composition is applied to a substrate, dried, and then cured by selectively irradiating ultraviolet rays, and then only the uncured portion is developed with an alkaline solution or the like. The photolithography method that removes and forms a pattern is the mainstream. This permanent mask resist has a role of preventing solder from adhering to an unnecessary portion of the conductor layer of the printed wiring board in the process of flip-chip mounting the semiconductor element on the printed wiring board via solder. Further, the permanent mask resist also has a role of preventing corrosion of the conductor layer and maintaining electrical insulation between the conductor layers when the printed wiring board is used.

Conventionally, a permanent mask resist in the production of a printed wiring board has been produced by a method such as screen printing or roll coating of a thermosetting or photosensitive resin composition.

For example, in a flexible wiring board using a mounting method such as FC (Flip Chip), TAB (Tape Automated Bonding) and COF (Chip On Film), a rigid wiring board, an IC chip, an electronic component or an LCD panel and a connection wiring pattern portion The thermosetting resin paste is screen-printed and heat-cured to form a permanent mask resist (see, for example, Patent Document 1).

Further, in recent years, as printed wiring boards have become thinner and higher in density, permanent mask resists are required to have low stress, high insulation reliability and toughness.

Japanese Unexamined Patent Publication No. 2003-198105

In the present invention, the cured product is a photosensitive resin composition having low stress properties, and the photosensitive resin composition has high insulation reliability and toughness even when used for forming a permanent mask resist of a thin printed wiring board. The purpose is to provide.

In order to achieve the above object, the inventors have repeatedly studied the characteristics and composition of the solder resist, and as a result, in the photosensitive resin composition using the acid-modified vinyl group-containing epoxy resin, the elastic modulus is high and the stress is low. It can be used as a permanent mask resist by applying the resin composition of the above, using an inorganic filler surface-treated with a silane coupling agent containing an amino group, and further containing the inorganic filler and a curing agent in a specific amount. We have found that a cured product having low stress, high insulation reliability and toughness can be obtained, and have completed the present invention. That is, the present invention provides the following photosensitive resin composition, a pattern cured film using the same, a method for producing the same, a photosensitive element, a printed wiring board, and a method for producing the same.

[1] Contains (A) acid-modified vinyl group-containing epoxy resin, (B) photopolymerizable monomer having an ethylenically unsaturated bond, (C) photopolymerization initiator, (D) inorganic filler and (E) curing agent. A photosensitive resin composition comprising an inorganic filler in which the inorganic filler (D) is surface-treated with a silane coupling agent having an amino group.

[2] The content of the (D) inorganic filler is 30 to 60% by mass of the total solid content in the photosensitive resin composition, and the content of the (E) curing agent is the said (A) acid. The photosensitive resin composition according to the above [1], which is 75 to 140 parts by mass per 100 parts by mass of a modified vinyl group-containing epoxy resin.

[3] A pattern cured film having a cured film formed in a pattern using the photosensitive resin composition according to the above [1] or [2].
[4] A step of applying the photosensitive resin composition according to the above [1] or [2] onto a substrate and drying it to form a coating film, and irradiating the coating film with active light to expose the coating film in a pattern. A method for producing a pattern-cured film, which comprises a step, a step of removing an unexposed portion by development to obtain a pattern resin film, and a step of curing the pattern resin film.

[5] A photosensitive element having a support and the photosensitive resin composition according to the above [1] or [2] as a photosensitive layer on the support.
[6] A printed wiring board comprising the photosensitive resin composition according to the above [1] or [2] or a permanent mask resist formed by using the photosensitive element according to the above [5].
[7] A step of forming a photosensitive layer on a substrate by using the photosensitive resin composition according to the above [1] or [2] or the photosensitive element according to the above [5]. A method for manufacturing a printed wiring board, which comprises, in order, a step of forming a resist pattern using the resist pattern and a step of curing the resist pattern to form a permanent mask resist.

According to the present invention, it is possible to provide a photosensitive resin composition which is a printed wiring board provided with a permanent mask resist, has low stress, and has high insulation reliability and toughness.

Hereinafter, preferred embodiments of the present invention will be described in detail.
[Photosensitive resin composition]
First, the photosensitive resin composition according to a preferred embodiment of the present invention will be described. In the present specification, (meth) acrylic acid means acrylic acid and its corresponding methacrylic acid, (meth) acrylate means acrylate and its corresponding methacrylate, and (meth) acryloyl group means acryloyl. It means a group and a corresponding methacrylic acid group, and the (meth) acryloyl group means an acryloyl group and a corresponding methacrylicoxy group.

The photosensitive resin composition of the present invention basically comprises (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable monomer having an ethylenically unsaturated bond, (C) a photopolymerization initiator, and (D). It contains an inorganic filler and an (E) curing agent (hereinafter, may be simply referred to as a component (A), a component (B), a component (C), a component (D), a component (E), etc.). ..

<(A) Acid-modified vinyl group-containing epoxy resin>
The (A) acid-modified vinyl group-containing epoxy resin used in the present invention will be described.
The (A) acid-modified vinyl group-containing epoxy resin is an epoxy resin modified with a vinyl group-containing organic acid, and is saturated with, for example, a resin obtained by reacting an epoxy resin with a vinyl group-containing monocarboxylic acid. Examples thereof include an epoxy resin obtained by reacting a polybasic acid anhydride containing a group or an unsaturated group.

The (A) acid-modified vinyl group-containing epoxy resin used in the present invention has a structural unit represented by the following general formula (1) from the viewpoint of being capable of alkaline development and having excellent resolution and adhesiveness. Novolac type epoxy resin (for example, novolak type epoxy resin represented by the following general formula (1')), bisphenol novolak type epoxy resin having a structural unit represented by the following general formula (2), and the following general formula It is obtained by reacting at least one epoxy resin (a) selected from the group consisting of bisphenol novolac type epoxy resins having the structural unit represented by (3) with a vinyl group-containing monocarboxylic acid (b). It is preferable that the resin (A') is obtained by reacting the resin (A') with a saturated or unsaturated group-containing polybasic acid anhydride (c).

(Epoxy resin (a))

[In the general formulas (1) and (1'), R ¹¹ represents a hydrogen atom or a methyl group, Y ¹ represents a hydrogen atom or a glycidyl group, and the molar ratio of a hydrogen atom to a glycidyl group in ^{Y 1 (} Hydrogen atom / glycidyl group) is 0/100 to 30/70. Further, in the general formula (1'), n1 represents a number of 1 or more, and a plurality of R ¹¹ and Y ¹ may be the same or different, but at least one Y ¹ represents a glycidyl group. ]

Epoxy resins having a structural unit represented by the general formula (1), and, in the epoxy resin represented by the general formula (1 '), the molar ratio of hydrogen atoms and a glycidyl group in Y ¹ (hydrogen atom / glycidyl The group) is 0/100 to 30/70, preferably 0/100 to 10/90.

The number of structural units in one molecule of the epoxy resin (a) having the structural unit represented by the general formula (1) and the number of structural units represented by n1 in the general formula (1') are 1. The number is as described above, preferably 10 to 200, more preferably 30 to 150, and even more preferably 30 to 100.
Here, the number of structural units of the structural unit indicates an integer value when the epoxy resin (a) is composed of a single type of molecule, and indicates a rational number which is an average value when the epoxy resin (a) is an aggregate of a plurality of types of molecules. .. Hereinafter, the same applies to the number of structural units.

[In the general formula (2), the two R ¹² each independently represent a hydrogen atom or a methyl group, two Y ² each independently represent a hydrogen atom or a glycidyl group. Incidentally, the two R ¹² may be the same or different, two Y ² may be the same or different. However, ^{at least one of Y 2} shows a glycidyl group. ]

The number of structural units in one molecule of the epoxy resin (a) having a structural unit represented by the general formula (2) is one or more, and has adhesion to a copper substrate, heat resistance, and electricity. From the viewpoint of improving the insulating property, it is preferably 10 to 100, more preferably 15 to 80, and even more preferably 15 to 70.

[In the general formula (3), the two R ¹³ each independently represent a hydrogen atom or a methyl group, two Y ³ are each independently a hydrogen atom or a glycidyl group. Incidentally, the two R ¹³ may be the same or different, two Y ³ may be the same or different. Provided that at least one of Y ³ represents a glycidyl group. ]

The number of structural units in one molecule of the epoxy resin (a) having a structural unit represented by the general formula (3) is one or more, and has adhesion to a copper substrate, heat resistance, and electricity. From the viewpoint of improving the insulating property, it is preferably 10 to 100, more preferably 15 to 80, and even more preferably 15 to 70.

As the epoxy resin (a), a novolak type epoxy resin having a structural unit represented by the above general formula (1), for example, the above general formula (1), from the viewpoint of being excellent in process margin and improving solvent resistance. The novolak type epoxy resin represented by ′) is preferable.

Examples of the novolac type epoxy resin having the structural unit represented by the general formula (1) include a phenol novolac type epoxy resin and a cresol novolac type epoxy resin. These novolak-type epoxy resins can be obtained, for example, by reacting a phenol novolak resin or cresol novolak resin with epichlorohydrin by a known method.

In order to promote the reaction between the hydroxyl group and epichlorohydrin, it is preferable to carry out the reaction at a reaction temperature of 50 to 120 ° C. in the presence of an alkali metal hydroxide in a polar organic solvent such as dimethylformamide, dimethylacetamide or dimethyl sulfoxide. When the reaction temperature is less than 50 ° C., the reaction becomes slow, and when the reaction temperature is 120 ° C., many side reactions tend to occur.

Examples of the phenol novolac type epoxy resin or cresol novolac type epoxy resin represented by the general formula (1') include YDCN-701, YDCN-702, YDCN-703, YDCN-704, YDCN-704L, YDPN-638, and YDPN. -602 (above, manufactured by Nittetsu Epoxy Manufacturing Co., Ltd., trade name), DEN-431, DEN-439 (above, manufactured by Dow Chemical Corporation, trade name), EOCN-120, EOCN-102S, EOCN-103S, EOCN- 104S, EOCN-1012, EOCN-1025, EOCN-1027, BREN (above, manufactured by Nippon Kayaku Co., Ltd., trade name), EPN-1138, EPN-1235, EPN-1299 (above, manufactured by BASF Japan Ltd., product) Name), N-730, N-770, N-865, N-870, N-665, N-673, VH-4150, VH-4240 (all manufactured by DIC Corporation, trade name) are commercially available. It is possible.

Further, as the epoxy resin (a), in addition to the epoxy resin having the structural unit represented by the above general formula (1), the warp property of the thin film substrate can be further reduced and the heat impact resistance (during the temperature cycle test). From the viewpoint of further improving the crack resistance), a bisphenol novolak type epoxy resin having a structural unit represented by the general formula (2) and / or the general formula (3) may be used.

Examples of the bisphenol novolak type epoxy resin having the structural unit represented by the general formula (3) include the EXA-7376 series (manufactured by DIC Co., Ltd., trade name ^{) in which R 13} is a hydrogen atom and Y ^{3 is a glycidyl group.} ), And EPON SU8 series (manufactured by Mitsubishi Chemical Co., Ltd., trade name) in ^{which R 13} is a methyl group and Y ^{3 is a glycidyl group are commercially available.}

[Vinyl group-containing monocarboxylic acid (b)]
Examples of the vinyl group-containing monocarboxylic acid (b) described above include acrylic acid, a dimer of acrylic acid, methacrylic acid, β-flufurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α-. Acrylic acid derivatives such as cyanosilicate, semi-ester compounds that are reaction products of hydroxyl group-containing acrylate and dibasic acid anhydride, vinyl group-containing monoglycidyl ether or vinyl group-containing monoglycidyl ester and dibasic acid anhydride. Examples thereof include semi-ester compounds which are reaction products of. The vinyl group-containing monocarboxylic acid (b) can be used alone or in combination of two or more.

The semi-ester compound can be obtained by reacting a hydroxyl group-containing acrylate, a vinyl group-containing monoglycidyl ether or a vinyl group-containing monoglycidyl ester with a dibasic acid anhydride in an equimolar ratio. These vinyl group-containing monocarboxylic acids (b) can be used alone or in combination of two or more.

Examples of the hydroxyl group-containing acrylate, vinyl group-containing monoglycidyl ether, and vinyl group-containing monoglycidyl ester used in the synthesis of the semiester compound include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, and hydroxybutyl acrylate. , Hydroxybutyl Methacrylate, Polyethylene Glycol Monoacrylate, Polyethylene Glycol Monomethacrylate, Trimethylol Propane Diacrylate, Trimethylol Propane Dimethacrylate, Pentaerythritol Triacrylate, Pentaerythritol Trimethacrylate, Dipentaerythritol Pentaacrylate, Pentaerythritol Pentamethacrylate, Examples thereof include glycidyl acrylate and glycidyl methacrylate.

As the dibasic acid anhydride used for the synthesis of the semiester compound, one containing a saturated group and one containing an unsaturated group can be used. Specific examples of dibasic acid anhydrides include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Acids, ethylhexahydrophthalic anhydride, phthalic anhydride and the like can be mentioned.

In the reaction between the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b) described above, the vinyl group-containing monocarboxylic acid (b) is preferably 0 with respect to 1 equivalent of the epoxy group of the epoxy resin (a). The reaction is carried out at a ratio of .5 to 1.05 equivalents, more preferably 0.6 to 1.05 equivalents. Further, it is particularly preferable to react at a ratio of 0.8 to 1.0 equivalent.

The epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b) can be dissolved in an organic solvent and reacted. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol and propylene glycol monomethyl ether. Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, and aliphatic carbides such as octane and decane. Examples thereof include petroleum-based solvents such as hydrogens, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

Furthermore, it is preferable to use a catalyst to accelerate the reaction. As the catalyst, for example, triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylmethylammonium iodide, triphenylphosphine and the like can be used. The amount of the catalyst used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass in total of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b).

Further, it is preferable to use a polymerization inhibitor for the purpose of preventing polymerization during the reaction. Examples of the polymerization inhibitor include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol and the like. The amount of the polymerization inhibitor used is preferably 0.01 to 1 part by mass with respect to 100 parts by mass in total of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b). The reaction temperature is preferably 60 to 150 ° C, more preferably 80 to 120 ° C.

Further, if necessary, a vinyl group-containing monocarboxylic acid (b), a phenolic compound such as p-hydroxyphenethyl alcohol, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, biphenyltetracarboxylic acid. It can be used in combination with a polybasic acid anhydride such as an anhydride.

As described above, the resin (A') obtained by reacting the epoxy resin (a) with the vinyl group-containing monocarboxylic acid (b) is the glycidyl group-containing vinyl group-containing monocarboxylic acid (b) of the epoxy resin (a). It is presumed that it has a hydroxyl group formed by the addition reaction with the carboxyl group of).

The above-mentioned resin (A ") used as one aspect of the acid-modified vinyl group-containing epoxy resin (A) is a saturated or unsaturated group-containing polybasic anhydride (A') in addition to the resin (A') obtained above. c) It is synthesized by reacting (hereinafter, may be simply referred to as polybasic anhydride (c)). In the resin (A ″) thus obtained, the resin (A') The acid-modified vinyl group-containing epoxy resin is obtained by semi-esterifying the hydroxyl group (including the hydroxyl group originally present in the epoxy resin (a)) and the acid anhydride group of the polybasic anhydride (c). It is inferred that.

[Polybasic acid anhydride (c)]
As the polybasic acid anhydride (c), one containing a saturated group or one containing an unsaturated group can be used. Specific examples of the polybasic acid anhydride (c) include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, and hexahydrophthalic anhydride. Examples thereof include methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride. The polybasic acid anhydride (c) can be used alone or in combination of two or more.

In the reaction between the resin (A') and the polybasic acid anhydride (c), the polybasic acid anhydride (c) was 0.1 to 1.0 equivalent to 1 equivalent of the hydroxyl group in the resin (A'). By reacting, the acid value of the acid-modified vinyl group-containing epoxy resin can be adjusted.

The acid value of the acid-modified vinyl group-containing epoxy resin (A) is preferably 30 to 150 mgKOH / g, more preferably 40 to 120 mgKOH / g, and particularly preferably 50 to 100 mgKOH / g. If the acid value is less than 30 mgKOH / g, the solubility of the photosensitive resin composition in a dilute alkaline solution tends to decrease, and if it exceeds 150 mgKOH / g, the electrical characteristics of the cured film tend to decrease.

The reaction temperature of the resin (A') and the polybasic acid anhydride (c) is preferably 60 to 120 ° C.

Further, if necessary, for example, a hydrogenated bisphenol A type epoxy resin can be partially used in combination as the epoxy resin (a). Further, as the (A) acid-modified vinyl group-containing epoxy resin, a styrene-maleic acid-based product such as a hydroxyethyl acrylate-modified product of a styrene-maleic anhydride copolymer or a hydroxyethyl acrylate-modified product of a styrene-maleic anhydride copolymer is used. A part of the resin can also be used in combination.

[(A) Molecular Weight of Acid-Modified Vinyl Group-Containing Epoxy Resin]
The weight average molecular weight of the component acid-modified vinyl group-containing epoxy resin (A) is preferably 3,000 to 30,000, more preferably 4 from the viewpoint of improving adhesion to the copper substrate, heat resistance, and electrical insulation. It is 000 to 25,000, particularly preferably 5,000 to 18,000. Here, the weight average molecular weight is a polyethylene-equivalent weight average molecular weight measured by a gel permeation chromatography (GPC) method using tetrahydrofuran as a solvent. More specifically, for example, a value measured by the following GPC measuring device and measuring conditions and converted using a standard polystyrene calibration curve can be used as the weight average molecular weight. In addition, a 5-sample set (“PStQuick MP-H” and “PStQuick B”, manufactured by Tosoh Corporation) is used as the standard polystyrene for preparing the calibration curve.
[GPC measuring device]
GPC device: High-speed GPC device "HCL-8320GPC", detector is differential refractometer or UV, manufactured by Tosoh Corporation Column: Column TSKgel SuperMultipore HZ-H (column length: 15 cm, column inner diameter: 4.6 mm), Tosoh stock Made by the company [Measurement conditions]
Solvent: tetrahydrofuran (THF)
Measurement temperature: 40 ° C
Flow rate: 0.35 ml / min Sample concentration: 10 mg / THF 5 ml
Injection volume: 20 μl

[Content of (A) acid-modified vinyl group-containing epoxy resin]
In the photosensitive resin composition of the present invention, the content of the (A) acid-modified vinyl group-containing epoxy resin is preferably 5 to 60% by mass based on the total solid content of the photosensitive resin composition. It is more preferably ~ 50% by mass, and particularly preferably 15-40% by mass. When the content of the component (A) is within the above range, a coating film having excellent heat resistance, electrical characteristics and chemical resistance can be obtained.

<(B) Photopolymerizable compound having an ethylenically unsaturated bond>
As the (B) photopolymerizable compound having an ethylenically unsaturated bond used in the photosensitive resin composition of the present invention, a compound having a molecular weight of 1000 or less is preferable from the viewpoint of heat resistance and insulation reliability, for example. Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, mono- or di (meth) acrylates of glycols such as ethylene glycol, methoxytetraethylene glycol and polyethylene glycol, (Meta) acrylamides such as N, N-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide, aminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate, hexanediol, tri Polyvalent alcohols such as methylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, tris-hydroxyethyl isocyanurate, or polyvalent (meth) acrylates of these ethylene oxides or propylene oxide adducts, phenoxyethyl (meth) acrylates. , Ethylene oxide of phenols such as polyethoxydi (meth) acrylate of bisphenol A or (meth) acrylate of propylene oxide adduct, glycidyl ether such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate ( Examples thereof include meth) acrylates, melamine (meth) acrylates, acrylamides, acrylonitriles, diacetone acrylamides, styrenes, vinyl toluene and the like. Further, it is more preferable to have three or more ethylenic bonds in one molecule in order to increase the crosslink density by photocuring and improve heat resistance and insulation reliability. Examples of the compound having such an ethylenically unsaturated bond include dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate. These (B) compounds having an ethylenically unsaturated group are used alone or in combination of two or more.

[(B) Content of photopolymerizable compound having ethylenically unsaturated bond]
(B) The content of the photopolymerizable compound having an ethylenically unsaturated bond is preferably 2 to 50% by mass, more preferably 3 to 30% by mass, based on the total amount of solids in the photosensitive resin composition. More preferably, it is 3 to 20% by mass. When it is 2% by mass or more, the light sensitivity is low, so that the tendency of the exposed portion to elute during development can be suppressed, and when it is 50% by mass or less, the decrease in heat resistance can be suppressed.

<(C) Photopolymerization Initiator>
Examples of the (C) photopolymerization initiator used in the photosensitive resin composition of the present invention include benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, and the like. 2,2-Diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl -1- [4- (Methylthio) phenyl] -2-morpholino-1-propanone, acetphenones such as N, N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1 -Anthraquinones such as chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; acetophenonedimethyl Ketals such as ketal and benzyldimethyl ketal; benzophenones such as benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis (diethylamino) benzophenone, Michler's ketone, 4-benzoyl-4'-methyldiphenylsulfide 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) ) -4,5-Diphenylimidazole dimer, 2- (o-methoxyphenyl) 4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4,5-Triaryl such as 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer, etc. Axidines such as imidazole dimer, 9-phenylaclydin, 1,7-bis (9,9'-acrydinyl) heptane; acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1 , 2-octanedione-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime) ), 1- [9-Ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] Ethanone 1- (O-acetyloxime), 1-Phenyl-1,2-propandion-2-[ Oxime esters such as O- (ethoxycarbonyl) oxime] can be mentioned. These (C) photopolymerization initiators may be used alone or in combination of two or more. In the embodiment of the present invention, among these polymerization initiators, 2,4,6-trimethylbenzoyldiphenylphosphine oxide having good curability at the bottom due to photobleaching (for example, Irgacure 819 manufactured by BASF Japan Ltd.) It is preferable to use 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (for example, Irgacure 369 manufactured by BASF Japan Ltd.), which is hard to volatilize and is hard to generate as outgas. ..

Further, such as tertiary amines such as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine (C'). The photopolymerization initiator may be used alone or in combination of two or more.

[(C) Content of Photopolymerization Initiator]
The content of the (C) photopolymerization initiator in the photosensitive resin composition of the present invention is preferably 0.2 to 20% by mass, more preferably 0, based on the total solid content of the photosensitive resin composition. It is 4 to 15% by mass, more preferably 0.6 to 10% by mass. Further, when the content of (C) the photopolymerization initiator is 0.2% by mass or more, the exposed portion is less likely to elute during development, and when it is 20% by mass or less, the decrease in heat resistance can be suppressed.

<(D) Inorganic filler>
Examples of the (D) inorganic filler used in the photosensitive resin composition of the present invention include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), titania (TIO ₂ ), and titanium oxide (Ta ₂ O ₅ ). Zirconia (ZrO ₂ ), Silicon Nitide (Si ₃ N ₄ ), Barium Titanium (BaO · TiO ₂ ), Barium Carbonate (BaCO ₃ ), Magnesium Carbonate, Aluminum Oxide, Aluminum Hydroxide, Magnesium Hydroxide, Lead Titanium ( PbO ・ TiO ₂ ), lead zircate titanate (PZT), lead lanthanum _{zircate titanate (PLZT), gallium oxide (Ga 2} O ₃ ), spinel (MgO ・ Al ₂ O ₃ ), mulite (3Al ₂ O ₃₎ · 2SiO _2), cordierite _{(2MgO · 2Al 2 O 3 /} 5SiO 2), talc _{(3MgO · 4SiO 2 · H 2} O), aluminum titanate _{(TiO 2 -Al 2 O 3)} , yttria-containing zirconia (Y ₂ O ₃ -ZrO _2), barium silicate (BaO · 8SiO _2), boron nitride (BN), calcium carbonate (CaCO _3), barium sulfate (BaSO _4), calcium sulfate (CaSO _4), zinc oxide (ZnO) , Magnesium titanate (MgO · TiO ₂ ), hydrotalcite, mica, calcined kaolin, carbon (C) and the like can be used. These (D) inorganic fillers can be used alone or in combination of two or more.

As the inorganic filler (D) used in the photosensitive resin composition of the present invention, it is practical to use one surface-treated with a silane coupling agent in order to disperse the inorganic filler (D) in the resin without agglomeration while maintaining the primary particle size. Is. As the silane coupling agent, generally available ones can be used, for example, alkylsilane, alkoxysilane, vinylsilane, epoxysilane, aminosilane, acrylicsilane, methacrylsilane, mercaptosilane, sulfidesilane, isocyanatesilane, etc. Sulfersilane, styrylsilane, alkylchlorosilane and the like can be used. Specific compound names include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, diisopropyldimethoxysilane, and isobutyltrimethoxy. Silane, diisobutyldimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octylriethoxysilane, n-dodecylmethoxysilane, phenyltrimethoxysilane, diphenyldimethoxy Silane, triphenylsilanol, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, n-octyldimethylchlorosilane, tetraethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) ) Aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, vinyl tri Acetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, allyltrimethoxysilane, diallyldimethylsilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxy Propyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, N- (1,3-dimethylbutylidene) -3-aminopropyltriethoxysilane, aminosilane , Monomethyltriisocyanatesilane, tetraisocyanatesilane, γ-isocyanappropyltriethoxysilane. The silane coupling agent to be used is preferably a type that reacts with the components contained in the photosensitive resin composition. For example, (A) an epoxy silane that reacts with a carboxyl group in an acid-modified vinyl group-containing epoxy resin. Acrylic silane, methacrylic silane, or an amino group that reacts with an epoxy group or forms a hydrogen bond with a hydroxyl group is preferable. Further, mercaptosilane and isocyanatesilane may be used, and these silanes react with (B) the ethylenically unsaturated group of the photopolymerizable monomer having an ethylenically unsaturated bond, and the silane coupling agent is used. It is thought that the same effect as the case will be exhibited. Among the above silane coupling agents, the silane coupling agent containing an amino group has high reactivity with the epoxy group-containing resin contained in the photosensitive resin composition, and in addition, has the effect of strengthening the bond between silica and the resin. Therefore, when a permanent mask resin is used, the strength and toughness of the film can be strengthened, which contributes to the improvement of insulation reliability in the high temperature and high humidity test and the crack resistance in the temperature cycle test. It is particularly useful in embodiments. As the silane coupling agent containing an amino group, among the silane compounds listed above, phenylaminosilanes such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-phenylaminopropyltrimethoxysilane are used. It is preferable to use it because the effect of the present invention can be obtained most.

Among the inorganic fillers (D), it is preferable to use silica fine particles from the viewpoint of improving low expansion coefficient and heat resistance. In addition, barium sulfate fine particles are used from the viewpoint of improving solder heat resistance, HAST property (insulation reliability), crack resistance (heat impact resistance), and adhesive strength between the underfill material and the cured film after the PCT test. It is also preferable to do so. Further, the silica fine particles are preferably surface-treated with alumina and / or an organic silane compound from the viewpoint of improving the anti-aggregation effect.

The average particle size of the inorganic filler (D) is preferably 0.01 to 1 μm, more preferably 0.1 to 1 μm from the viewpoint of practicality and resolution, and 0.3 to 0.7 μm. It is particularly preferable to have. The maximum particle size of the (D) inorganic filler is preferably 0.1 to 5 μm, more preferably 0.1 to 3 μm, and particularly preferably 0.1 to 1 μm. If the maximum particle size exceeds 5 μm, the resolution and insulation reliability tend to be impaired.

[(D) Content of Inorganic Filler]
In the photosensitive resin composition of the present invention, the content of the (D) inorganic filler surface-treated with a coupling agent having an amino group is a solid of the photosensitive resin composition from the viewpoint of resolution and low thermal expansion rate. It is 30 to 60% by mass, preferably 30 to 55% by mass, and more preferably 35 to 50% by mass based on the total amount. When the content of the inorganic filler (D) is within these ranges, the low coefficient of thermal expansion, heat resistance, insulation reliability, thermal shock resistance, resolution, film strength and the like can be further improved. If the filling amount exceeds 60% by mass, it becomes difficult to disperse in the resin, and the flowability of the photosensitive resin composition tends to decrease. If the filling amount is less than 30% by mass, the coefficient of thermal expansion during heating is not reduced, the stress reduction is insufficient, and the warpage tends to be impossible to reduce. In addition, it tends to be difficult to obtain crack resistance at the time of reflow mounting.

<(E) Hardener>
The (E) curing agent used in the photosensitive resin composition of the present invention includes a compound that itself cures with heat, ultraviolet rays, etc., or (A) a carboxyl group, a hydroxyl group and heat of an acid-modified vinyl group-containing epoxy resin. A compound that reacts with ultraviolet rays or the like and cures is preferable. By using the (E) curing agent, it is possible to improve the heat resistance of the cured film formed from the photosensitive resin composition, the adhesiveness to the underfill material and the substrate, the chemical resistance, and the like.

Examples of the curing agent (E) include thermosetting compounds such as epoxy compounds, melamine compounds, urea compounds, oxazoline compounds, and block-type isocyanates. Examples of the epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, novolak type epoxy resin, bisphenol S type epoxy resin, and biphenyl type epoxy resin. , Naphthalene type epoxy resin, dicyclo type epoxy resin, hydantin type epoxy resin, heterocyclic epoxy resin such as triglycidyl isocyanurate, and epoxy resin such as bixilenol type epoxy resin. Examples of the melamine compound include triazine derivatives such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xysilyl-S-triazine, and triaminotriazine, and hexa (N). -Methyl) melamine, hexamethoxymelamine, hexabutoxyd melamine and the like can be mentioned. Examples of the urea compound include dimethylol urea and the like. These (E) curing agents may be used alone or in combination of two or more.

The curing agent (E) cures by reacting with a carboxyl group, a hydroxyl group, and a glycidyl group with heat, ultraviolet rays, etc. from the viewpoint of further improving the heat resistance of the cured film and the adhesiveness with the underfill material and the substrate. It is preferable to contain the compound as an essential component. Examples of such a compound include the above-mentioned melamine compound and the like. The melamine compound is particularly preferably contained in combination with an epoxy resin.

Further, the curing agent (E) preferably contains an epoxy compound (epoxy resin) and / or a block-type isocyanate from the viewpoint of further improving the heat resistance of the cured film, and the epoxy compound and the block-type isocyanate are preferably contained. May be used in combination with.

As the block-type isocyanate, an addition reaction product of a polyisocyanate compound and an isocyanate blocking agent is used. Examples of the polyisocyanate compound include tolylene diisocyanate, xylylene diisocyanate, phenylenediocyanate, naphthylene diisocyanate, bis (isocyanate methyl) cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate and the like. Polyisocyanate compounds, as well as these adducts, burettes and isocyanurates.

Examples of the isocyanate blocking agent include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-parellolactam, γ-butyrolactam and β-propiolactam; Active methylene blocking agents such as ethyl acetoacetate and acetylacetone; methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl Alcohol-based blocking agents such as ether, methyl glycolate, butyl glycolate, diacetone alcohol, methyl lactate and ethyl lactate; oxime-based blocking agents such as formaldehyde oxime, acetoaldoxime, acetoxime, methyl ethyl ketoxim, diacetyl monooxime and cyclohexane oxime. Mercaptan-based blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methyl thiophenol, ethyl thiophenol; acid amide-based blocking agents such as acetate amide and benzamide; imides such as succinate imide and maleate imide. Examples of the blocking agent: an amine-based blocking agent such as xylidine, aniline, butylamine, and dibutylamine; an imidazole-based blocking agent such as imidazole and 2-ethylimidazole; and an imine-based blocking agent such as methyleneimine and propyleneimine.

[(E) Curing agent content]
(E) The curing agent may be used alone or in combination of two or more. The content of the curing agent (E) is preferably 2 to 40% by mass, more preferably 3 to 30% by mass, and 5 to 20% by mass, based on the total solid content of the photosensitive resin composition. % Is particularly preferable. (E) By setting the content of the curing agent in the range of 2 to 40% by mass, the heat resistance of the cured film formed is further improved while maintaining good developability, and further, it is used as a permanent mask resist. It is possible to prevent peeling between the substrates.

Further, in the photosensitive resin composition of the present invention, the content of the (E) curing agent per 100 parts by mass of the content of the (A) acid-modified vinyl group-containing epoxy resin is 75 to 140 parts by mass, preferably 75. It is ~ 135 parts by mass, more preferably 80 to 130 parts by mass. If the content of the (E) curing agent per 100 parts by mass of the component (A) is less than 75 parts by mass, the improvement of the adhesiveness to the underfill material and the substrate and the chemical resistance tends to be insufficient.

Further, as described above, the (E) curing agent preferably contains an epoxy resin and a melamine compound, and the content of the epoxy resin is improved from the viewpoint of improving the adhesiveness to the underfill material and the substrate and the chemical resistance. Is preferably 15 to 100 parts by mass, more preferably 20 to 90 parts by mass, and further preferably 25 to 80 parts by mass per 100 parts by mass of the (A) acid-modified vinyl group-containing epoxy resin. The content of the melamine compound is preferably 15 to 100 parts by mass per 100 parts by mass of the (A) acid-modified vinyl group-containing epoxy resin from the viewpoint of improving the adhesiveness to the underfill material and the substrate and the chemical resistance. Yes, more preferably 20 to 90 parts by mass, and particularly preferably 25 to 80 parts by mass.

<Other ingredients>
In addition to the above-mentioned components (A) to (E), the photosensitive resin composition of the present invention contains (F) pigment, (G) elastomer, (H) epoxy resin curing agent, and (I) heat, if necessary. It may further contain a plastic resin, (J) and other additives. Hereinafter, each component will be described.

<(F) Pigment>
The photosensitive resin composition of the present invention preferably contains (F) pigment in order to improve the distinctiveness and appearance of the manufacturing apparatus. The pigment (F) is preferably used according to a desired color when concealing wiring or the like. As the pigment (F), a colorant that develops a desired color may be appropriately selected and used. For example, phthalocyanine blue, phthalocyanine green, iodin green, diazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black. Known colorants such as, etc. are preferably mentioned.

[(F) Pigment content]
When the (F) pigment is used, the content of the (F) pigment is preferably 0.1 to 10% by mass based on the total amount of solids in the photosensitive resin composition from the viewpoint of hiding the wiring more. It is more preferably 0.1 to 5% by mass, and particularly preferably 0.5 to 3% by mass.

<(G) Elastomer>
Further, the photosensitive resin composition of the present invention preferably further contains (G) an elastomer. By containing the elastomer (G), the stress of the cured film formed from the photosensitive resin composition can be reduced, and the flexibility, the underfill material, the adhesiveness to the substrate, and the like can be further improved. .. That is, when the bridging reaction (curing reaction) proceeds in the photosensitive resin composition of the present invention due to ultraviolet rays or heat, the (A) acid-modified vinyl group-containing epoxy resin is cured and shrunk, and is distorted inside the resin (inside). The problem that (stress) is applied and the flexibility and adhesiveness are lowered can be solved by adding the (G) elastomer.

Examples of the (G) elastomer include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers. These (G) elastomers are composed of a hard segment component and a soft segment component, and generally the former contributes to heat resistance and strength, and the latter contributes to flexibility and toughness, respectively.

Examples of the styrene-based elastomer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-ethylene-propylene-styrene block copolymer.

In addition to styrene, styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene can be used as the components constituting the styrene-based elastomer. More specifically, Tough Plen, Solpren T, Asaplen T, Tough Tech (above, Asahi Kasei Co., Ltd., product name), Elastomer AR (Aron Kasei Co., Ltd., product name), Clayton G, Califlex (above, Shell Japan). JSR-TR, TSR-SIS, Dynaron (above, JSR Co., Ltd., product name), Denka STR (Denka Co., Ltd., product name), Quintac (Nippon Zeon Co., Ltd., product name) Product name), TPE-SB series (manufactured by Sumitomo Chemical Co., Ltd., product name), Lavalon (manufactured by Mitsubishi Chemical Co., Ltd., product name), Septon, Hybler (manufactured by Clare Co., Ltd., product name), Sumiflex (Sumitomo) Bakelite Co., Ltd., trade name), Leostomer, Actimer (above, Riken Technos Co., Ltd., trade name) and the like can be used.

The olefin-based elastomer is a copolymer of α-olefin having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene and 4-methyl-pentene. Specific examples thereof include ethylene-propylene copolymer (EPR), ethylene-propylene-diene copolymer (EPDM), dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylenenorbornene, ethylidenenorbornene, butadiene, and the like. Examples thereof include a copolymer of an α-olefin and a non-conjugated diene having 2 to 20 carbon atoms such as isoprene, and a carboxy-modified NBR obtained by copolymerizing a butadiene-acrylonitrile copolymer with methacrylic acid. More specifically, ethylene / α-olefin copolymer rubber, ethylene / α-olefin / non-conjugated diene copolymer rubber, propylene / α-olefin copolymer rubber, butene / α-olefin copolymer rubber Can be mentioned. Furthermore, specifically, Mirastoma (manufactured by Mitsui Chemicals Co., Ltd., trade name), EXACT (manufactured by Exxon Mobile Co., Ltd., trade name), ENGAGE (manufactured by Dow Chemical Co., Ltd.), hydrogenated styrene-butadiene rubber "DYNABON HSBR" ( JSR Corporation, trade name), butadiene-acrylonitrile copolymer "NBR series" (JSR Corporation, trade name), or both-terminal carboxyl group-modified butadiene-acrylonitrile copolymer "XER series" (JSR Corporation) BF-1000 (trade name, manufactured by Nippon Soda Co., Ltd.), PB-3600 (trade name, manufactured by Daicel Corporation), etc., which is an epoxidized polybudadien obtained by partially epoxidizing polybutadiene. it can.

The urethane-based elastomer is composed of a structural unit consisting of a hard segment composed of a low molecular weight glycol and a diisocyanate and a soft segment composed of a polymer (long chain) diol and a diisocyanate.

As the low molecular weight glycol, for example, short chain diols such as ethylene glycol, propylene glycol, 1,4-butanediol and bisphenol A can be used. The number average molecular weight of the short chain diol is preferably 48 to 500.

Examples of the polymer (long chain) diol include polypropylene glycol, polytetramethylene oxide, poly (1,4-butylene adipate), poly (ethylene 1,4-butylene adipate), polycaprolactone, and poly (1,6). -Hexylene carbonate), poly (1,6-hexylene neopentylene adipate) can be mentioned. The number average molecular weight of the polymer (long chain) diol is preferably 500 to 10,000.

Specific examples of the urethane-based elastomer include PANDEX T-2185, T-2983N (manufactured by DIC Corporation, trade name), and Miractran E790 (manufactured by Nippon Miractran Co., Ltd., trade name).

Examples of the polyester-based elastomer include those obtained by polycondensing a dicarboxylic acid or a derivative thereof and a diol compound or a derivative thereof.

Specific examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and aromatic dicarboxylic acids in which the hydrogen atom of these aromatic nuclei is substituted with a methyl group, an ethyl group, a phenyl group, or the like. Examples thereof include aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid and dodecanedicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. These compounds may be used alone or in combination of two or more.

Specific examples of the diol compound include fats such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, and 1,4-cyclohexanediol. Examples thereof include group diols and alicyclic diols, or divalent phenols represented by the following general formula (4).

[General formula (4), Y ¹¹ represents an alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 4 to 8 carbon atoms, -O-, -S-, or -SO _2- , and R ²¹ and R. ²² each independently represents a halogen atom or an alkyl group having 1 to 12 carbon atoms, p and q each independently represent an integer of 0 to 4, and r represents an integer of 0 or 1. ]

Specific examples of the dihydric phenol represented by the general formula (4) include bisphenol A, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) propane, and resorcin. These compounds may be used alone or in combination of two or more.

Further, a multi-block copolymer having an aromatic polyester (for example, polybutylene terephthalate) moiety as a hard segment component and an aliphatic polyester (for example, polytetramethylene glycol) moiety as a soft segment component can be used. There are various grades depending on the type, ratio, and molecular weight of the hard segment and the soft segment. Specific examples include Hytrel (manufactured by Toray DuPont Co., Ltd., product name), Perprene (manufactured by Toyobo Co., Ltd., product name), Esper (manufactured by Hitachi Kasei Co., Ltd., product name) and the like.

Polyamide-based elastomers are roughly classified into two types: polyether block amide type and polyether ester block amide type, which use polyamide for the hard segment and polyether or polyester for the soft segment.

As the polyamide, polyamide-6, 11, 12, and the like can be used. As the polyether, polyoxyethylene, polyoxypropylene, polytetramethylene glycol and the like can be used. Specifically, UBE Polyamide Elastoma (manufactured by Ube Industries, Ltd., product name), Daiamide (manufactured by Daicel Ebonic Co., Ltd., product name), PEBAX (manufactured by Toray Co., Ltd., product name), Grillon ELY (Mschemy Japan Co., Ltd.) Company-made, product name), Nopamid (Mitsubishi Chemical Co., Ltd., product name), Grelak (DIC Co., Ltd., product name) and the like can be used.

As the acrylic elastomer, acrylic acid ester is the main component, and ethyl acrylate, butyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate and the like are used. Further, as the cross-linking point monomer, glycidyl methacrylate, allyl glycidyl ether and the like can be used. Furthermore, acrylonitrile and ethylene can be copolymerized. Specifically, an acrylonitrile-butyl acrylate copolymer, an acrylonitrile-butyl acrylate-ethyl acrylate copolymer, an acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer and the like can be used.

The silicone-based elastomer contains, for example, organopolysiloxane as a main component, and is classified into polydimethylsiloxane-based, polymethylphenylsiloxane-based, and polydiphenylsiloxane-based. Some are modified with vinyl groups, alkoxy groups, etc. Specific examples include the KE series (manufactured by Shin-Etsu Chemical Co., Ltd., product name), SE series, CY series, SH series (all manufactured by Toray Dow Corning Co., Ltd., product name) and the like.

In addition to the above-mentioned elastomer, a rubber-modified epoxy resin can also be used. The rubber-modified epoxy resin contains, for example, a part or all of the epoxy groups of the above-mentioned bisphenol F type epoxy resin, bisphenol A type epoxy resin, salicylaldehyde type epoxy resin, phenol novolac type epoxy resin or cresol novolac type epoxy resin. It is obtained by modifying with a terminal carboxylic acid-modified butadiene-acrylonitrile rubber, a terminal amino-modified silicone rubber, or the like. Among these elastomers, in terms of shear adhesiveness, both-terminal carboxyl group-modified butadiene-acrylonitrile copolymer and Esper, which is a polyester-based elastomer having a hydroxyl group (manufactured by Hitachi Kasei Co., Ltd., Esper 1612, 1620, trade name) , Epoxypolybudadiene and the like are preferable. Further, an elastomer that is liquid at room temperature is particularly preferable.

[Content of (G) elastomer]
When the (G) elastomer is used, the content thereof is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, based on the total solid content of the photosensitive resin composition. It is particularly preferably 10% by mass. By keeping the content of the elastomer (G) in the range of 1 to 20% by mass, it is possible to further improve the heat impact resistance and the adhesive strength between the underfill material and the cured film while maintaining good developability. it can. Further, when used for a thin film substrate, the warp property of the thin film substrate can be reduced.

<(H) Epoxy resin curing agent>
An epoxy resin curing agent (H) may be added to the photosensitive resin composition of the present invention for the purpose of further improving various properties such as heat resistance, adhesiveness, and chemical resistance of the cured film to be formed. ..

Specific examples of such (H) epoxy resin curing agent include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-. Imidazole derivatives such as methyl-5-hydroxymethylimidazole; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulphon, dicyandiamide, urea, urea derivatives, melamine, polybasic hydrazide Polyamines such as; these organic acid salts and / or epoxy adducts: amine complexes of boron trifluoride; trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholin , Hexa (N-methyl) melamine, 2,4,6-tris (dimethylaminophenol), tetramethylguanidine, m-aminophenol and other tertiary amines; polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac Polyphenols such as tributylphosphine, triphenylphosphine, organic phosphines such as tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide, hexadecyltributylphosnium chloride and the like. Tertiary ammonium salts such as benzyltrimethylammonium chloride, phenyltributylammonium chloride; the above-mentioned polybasic acid anhydrides; diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrilium Hexafluorophosphate and the like can be mentioned. These (H) epoxy resin curing agents may be used alone or in combination of two or more.

[Content of (H) epoxy resin curing agent]
When the epoxy resin curing agent (H) is used, the content thereof is preferably 0.01 to 20% by mass, preferably 0.1 to 10% by mass, based on the total solid content of the photosensitive resin composition. More preferably.

<(I) Thermoplastic resin>
Further, (I) a thermoplastic resin can be added to the photosensitive resin composition of the present invention in order to further improve the flexibility of the cured film.

Examples of the thermoplastic resin (I) include acrylic resin and urethane resin. (I) When the thermoplastic resin is contained, the content is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, based on the total solid content of the photosensitive resin composition. ..

<(J) Other additives>
Further, the photosensitive resin composition of the present invention contains, if necessary, organic fine particles such as melamine and organic bentonite, polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol and pyrogallol, and benton, montmorillonite and the like. Various known and commonly used additives such as thickeners, silicone-based, fluorine-based, and vinyl resin-based defoamers, silane coupling agents, and diluents can be added. Furthermore, flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, phosphate compounds of phosphorus compounds, aromatic condensed phosphoric acid esters, and halogen-containing condensed phosphoric acid esters can also be added.

As the diluent, for example, an organic solvent can be used. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol and propylene glycol monomethyl ether. Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, and aliphatic carbides such as octane and decane. Examples thereof include petroleum-based solvents such as hydrogens, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. Diluents may be used alone or in combination of two or more. When a diluent is used, the content can be appropriately adjusted from the viewpoint of coatability of the photosensitive resin composition.

The photosensitive resin composition of the present invention can be obtained by uniformly kneading and mixing each of the above-mentioned components with a roll mill, a bead mill or the like.

<Preparation of cured film and cured film>
The cured film of the present invention is a cured film formed by curing the photosensitive resin composition of the present invention, and is usually formed as a patterned pattern cured film. This pattern cured film is, for example, a step of applying the photosensitive resin composition of the present invention on a substrate such as a copper-clad laminate and drying it to form a coating film, and irradiating the coating film with active light to form a pattern. It can be produced by sequentially performing a step of exposing in a shape, a step of removing an unexposed portion by development to obtain a pattern resin film, and a step of curing the pattern resin film.

In one embodiment, the photosensitive resin composition of the present invention can be used for producing a cured film such as a permanent mask resist by forming an image as follows, for example.

That is, a substrate such as a copper-clad laminate is coated with a film thickness of 10 to 200 μm by a method such as a screen printing method, a spray method, a roll coating method, a curtain coating method, or an electrostatic coating method, and then a coating film is applied to 60. After drying at ~ 110 ° C., the negative film is brought into direct contact (or non-contact via a transparent film) and the active light (eg, ultraviolet light) is exposed at an exposure amount of ^{preferably 10 to 1,000 mJ / cm 2.} After irradiation, the unexposed portion is dissolved and removed (developed) with a dilute alkaline aqueous solution or an organic solvent to obtain a patterned resin film. Next, the patterned resin film, which is an exposed portion, is sufficiently cured by post-exposure (ultraviolet exposure) and / or post-heating to obtain a cured film. The post-exposure is preferably performed at an exposure amount of, for example, 1 to 5 J / cm ² , and the post-heating is preferably performed at 100 to 200 ° C. for 30 minutes to 12 hours.

<Photosensitive element>
Further, the photosensitive resin composition of the present invention can be laminated on a support to form a photosensitive element. The photosensitive element of the present invention has, for example, a support and a photosensitive layer on which the photosensitive resin composition of the present invention is used. The thickness of the layer made of the photosensitive resin composition is not particularly limited, but is preferably 10 to 100 μm. Examples of the support include polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyolefins such as polypropylene and polyethylene. The thickness of the support is not particularly limited, but is preferably in the range of 5 to 100 μm. The photosensitive layer made of the photosensitive resin composition is preferably formed by applying and drying a solution of the photosensitive resin composition on a support.
The coating film can be dried by hot air drying, far infrared rays, a dryer using near infrared rays, or the like, and the drying temperature is, for example, preferably 60 to 120 ° C., more preferably 70 to 110 ° C. More preferably, it is 80 to 100 ° C. The drying time is, for example, preferably 1 to 60 minutes, more preferably 2 to 30 minutes, and even more preferably 5 to 20 minutes.

Further, in the photosensitive element of the present invention, the protective layer can be laminated on the surface of the photosensitive layer opposite to the surface in contact with the support. As the protective layer, for example, a polymer film such as polyethylene or polypropylene may be used. Further, a polymer film similar to the carrier film described above may be used, or a different polymer film may be used.

<Printed circuit board>
The printed wiring board of the present invention comprises a permanent mask resist formed by the photosensitive resin composition of the present invention.
The permanent mask resist formed from the photosensitive resin composition of the present invention has high rigidity, low stress, and excellent adhesion to a substrate or an underfill material. Therefore, the permanent mask resist can be peeled off or the wiring board can be peeled off. It is possible to obtain a printed wiring board in which warpage and the like are eliminated.

[Manufacturing method of printed wiring board]
In the method for producing a printed wiring board of the present invention, a photosensitive layer is provided on a substrate, for example, a metal-clad laminate such as a copper-clad laminate, using the photosensitive resin composition of the present invention or the photosensitive element of the present invention. The steps include a step of forming a resist pattern using this photosensitive layer, and a step of curing the resist pattern to form a permanent mask resist. The details of each step are as described in the above-mentioned items of <Preparation of cured film> and <Photosensitive element>.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Synthesis Example 1: Production of Acid-Modified Vinyl Group-Containing Epoxy Resin (A-1)]
^{Bisphenol F novolac type epoxy resin having a structural unit (R 13} = hydrogen atom, Y ³ = glycidyl group) represented by the above general formula (3) (trade name: EXA-7376, manufactured by DIC Co., Ltd., epoxy equivalent: 186 ) 350 parts by mass, 70 parts by mass of acrylic acid, 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate were charged and reacted by heating at 90 ° C. and stirring to completely dissolve the mixture. Next, the obtained solution was cooled to 60 ° C., 2 parts by mass of triphenylphosphine was added, and the mixture was heated to 100 ° C. and reacted until the acid value of the solution reached 1 mgKOH / g to obtain the resin (A'). The solution to be contained was obtained. To the solution after the reaction, 98 parts by mass of tetrahydrophthalic anhydride (THPAC) and 85 parts by mass of carbitol acetate were added, heated to 80 ° C., reacted for about 6 hours, and then cooled to have a solid content concentration of 73 parts by mass. % (A) of THPAC-modified bisphenol F-type novolak epoxy acrylate (hereinafter referred to as "acid-modified vinyl group-containing epoxy resin (A-1)"; acid value: 75 mgKOH / g, weight average molecular weight: 10000). A solution was obtained.

(Examples 1 to 3 and Comparative Examples 1 to 3)
Each material shown in Table 1 below is blended in the blending amount (unit: parts by mass) shown in the same table, kneaded with a three-roll mill, and carbitol acetate is added so that the solid content concentration becomes 70% by mass. , A photosensitive resin composition was obtained. The blending amount of each material in Table 1 below indicates the blending amount of the solid content.

The details of each material in Table 1 are as follows.
* 1 (Acid-modified vinyl group-containing epoxy resin (A-1)): THPAC-modified bisphenol F-type novolak epoxy acrylate produced in Synthesis Example 1 * 2 (Aronix M402): Dipentaerythritol hexaacrylate (manufactured by Toa Synthetic Co., Ltd., Product name)
* 3 (Irgacure 369): 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (manufactured by BASF Japan Ltd., trade name)
* 4 (SFP-20M): Silica fine particles (manufactured by Denka Co., Ltd., product name)
* 5 (Surface-treated silica): Silica fine particles (manufactured by Admatex Co., Ltd., product name)
* 6 (YSLV-80XY): Epoxy resin (Novolac type epoxy resin, manufactured by Nippon Steel Chemical & Materials Co., Ltd., product name)
* 7 (RE-306): Epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name),
* 8 (PB-3600): Epoxy-polybutadiene (manufactured by Daicel Corporation, trade name)

The warpage, insulation reliability, and crack resistance of the printed circuit boards using the photosensitive resin compositions of Examples and Comparative Examples as the resist material were evaluated as follows.

[Board warp]
The photosensitive resin compositions of Examples and Comparative Examples were applied to a copper-clad laminated substrate (E-700G, manufactured by Hitachi Kasei Co., Ltd.) having a size of 74 mm × 240 mm by a screen printing method so that the film thickness after drying was 15 μm. After coating, it was dried at 75 ° C. for 30 minutes using a hot air circulation type dryer. A resist-cured film was formed by irradiating the surface of the obtained coating film with ^{ultraviolet rays having an integrated exposure amount of 100 mJ / cm 2} in a pattern and developing with a 1% by mass aqueous sodium carbonate solution for 60 seconds. ^{Next, an exposure amount of 2000 mJ / cm 2} was exposed using an ultraviolet exposure device, and the test piece was heated at 170 ° C. for 1 hour to prepare a test piece. The warp of the substrate was evaluated as “x” when the warp was 2 mm or more and “◯” when the warp was 2 mm or less. The evaluation results are shown in Table 2.

[Insulation reliability]
A comb-shaped electrode with a line / space of 20 μm / 20 μm by etching the copper surface of a printed wiring board substrate (E-679, manufactured by Hitachi Kasei Co., Ltd., trade name) in which a 12 μm thick copper foil is laminated on a glass epoxy base material. Was formed. Using this substrate as an evaluation substrate, a cured product of the resist was formed on the substrate as described above, and then exposed under the conditions of 135 ° C., 85%, and 5 V for 200 hours. Then, the degree of migration was observed with a 100x metallurgical microscope and evaluated according to the following criteria. That is, those in which migration did not occur in the permanent resist film and the resistance value did not decrease were evaluated as “◯”, and those in which migration occurred significantly and the resistance value decreased were evaluated as “x”.
[Crack resistance]
A cured resist was formed on the copper surface of a printed wiring board substrate (E-679, manufactured by Hitachi Kasei Co., Ltd., trade name) in which a 12 μm thick copper foil was laminated on a glass epoxy base material, and -55. A thermal history was added with ° C./30 minutes and 155 ° C./30 minutes as one cycle, and after 1000 cycles, visual observation and microscopic observation were performed. No cracks were marked with "○", and cracks were marked with "x".

As is clear from the table, in Examples 1 to 3, not only the warpage of the substrate can be reduced because the cured product of the photosensitive resin composition has low stress, but also the temperature is high because of high insulation reliability and toughness. It also has excellent crack resistance during cycle tests. On the other hand, it can be seen that Comparative Examples 1 and 2 have insufficient stress reduction, and Comparative Example 3 has insufficient insulation reliability and crack resistance due to the toughness of the cured product. As described above, the comparative example could not satisfy these three characteristics at the same time. Therefore, according to the present invention, it is possible to obtain a photosensitive resin composition having low stress and high insulation reliability and toughness.

Claims (14)

A curing agent containing (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable monomer having an ethylenically unsaturated bond, (C) a photopolymerization initiator, (D) an inorganic filler and (E) a melamine compound. A photosensitive resin composition containing, wherein the inorganic filler (D) is surface-treated with a silane coupling agent having an amino group. The content of the (D) inorganic filler is 30 to 60% by mass of the total solid content in the photosensitive resin composition, and the content of the (E) curing agent is the (A) acid-modified vinyl group. The photosensitive resin composition according to claim 1, wherein the content is 75 to 140 parts by mass per 100 parts by mass of the epoxy resin contained. The acid-modified vinyl group-containing epoxy resin (A) is synthesized by using a novolac type epoxy resin having a structural unit represented by the following general formula (1). An acid-modified vinyl group-containing epoxy resin having the following general formula (1) An acid-modified vinyl group-containing epoxy resin synthesized using a bisphenol novolac type epoxy resin having a structural unit represented by 2), and a bisphenol novolac type epoxy resin having a structural unit represented by the following general formula (3). The photosensitive resin composition according to claim 1 or 2, which contains at least one selected from the group consisting of acid-modified vinyl group-containing epoxy resins synthesized using the epoxy resin.
[In the general formula (1), R ¹¹ represents a hydrogen atom or a methyl group, Y ^{1 having} a plurality of Y 1 represents a hydrogen atom or a glycidyl group, and a molar ratio of a hydrogen atom to a glycidyl group (hydrogen atom / glycidyl group). Is 0/100 to 30/70. ]
[In the general formula (2), R ¹² independently represents a hydrogen atom or a methyl group, Y ² independently represents a hydrogen atom or a glycidyl group, and the two R ^12s may be the same or different. , At ^{least one of Y 2} represents a glycidyl group. ]
[In the general formula (3), R ¹³ independently represents a hydrogen atom or a methyl group, Y ³ independently represents a hydrogen atom or a glycidyl group, and the two R ^13s may be the same or different. provided that at least one of Y ³ represents a glycidyl group. ] The acid-modified vinyl group-containing epoxy resin (A) is a novolac type epoxy resin having a structural unit represented by the general formula (1), and a bisphenol novolac type epoxy having a structural unit represented by the general formula (2). At least one epoxy resin (a) selected from the group consisting of a resin and a bisphenol novolac type epoxy resin having a structural unit represented by the general formula (3), and a vinyl group-containing monocarboxylic acid (b) are used. The photosensitive resin composition according to claim 3, which is a resin obtained by reacting a saturated or unsaturated group-containing polybasic acid anhydride (c) with the reacted resin (A'). Any of claims 1 to 4, wherein the curing agent (E) contains a compound that cures by reacting with a carboxyl group and a hydroxyl group, and a compound that cures by reacting with a carboxyl group, a hydroxyl group and a glycidyl group. The photosensitive resin composition according to item 1. The (E) curing agent contains an epoxy resin and a melamine compound, and the content of the epoxy resin in the (E) curing agent is 15 to 100 parts by mass per 100 parts by mass of the (A) acid-modified vinyl group-containing epoxy resin. The photosensitive resin composition according to claim 5, wherein the content of the melamine compound in the (E) curing agent is 15 to 100 parts by mass per 100 parts by mass of the (A) acid-modified vinyl group-containing epoxy resin. Stuff. The present invention according to any one of claims 1 to 6, wherein the photopolymerizable monomer having an ethylenically unsaturated bond (B) is a polyfunctional photopolymerizable monomer having three or more ethylenically unsaturated bonds in one molecule. The photosensitive resin composition according to the above. The photosensitive resin composition according to any one of claims 1 to 7, further comprising (F) a pigment. The photosensitive resin composition according to any one of claims 1 to 8, further comprising (G) an elastomer. A pattern cured film having a cured film formed in a pattern using the photosensitive resin composition according to any one of claims 1 to 9. A step of applying the photosensitive resin composition according to any one of claims 1 to 9 onto a substrate and drying it to form a coating film, and a step of irradiating the coating film with active light to expose the coating film in a pattern. A method for producing a pattern-cured film, which comprises a step of removing an unexposed portion by development to obtain a pattern resin film and a step of curing the pattern resin film. A photosensitive element having a support and a photosensitive resin composition according to any one of claims 1 to 9 as a photosensitive layer on the support. A printed wiring board comprising the photosensitive resin composition according to any one of claims 1 to 9 or a permanent mask resist formed by using the photosensitive element according to claim 12. A step of forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of claims 1 to 9 or the photosensitive element according to claim 12, using the photosensitive layer. A method for manufacturing a printed wiring board, which comprises, in order, a step of forming a resist pattern and a step of curing the resist pattern to form a permanent mask resist.