JP2024036366A - 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 use as a protective film on printed wiring boards, and more specifically, in the field of resists for semiconductor package substrates, etc., for use as a permanent mask resist on protective films for printed wiring boards. The present invention relates to a photosensitive resin composition, a patterned cured film using the photosensitive resin composition, a method for producing the same, a photosensitive element, 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 printed wiring boards. The method for forming a photosensitive resist pattern is to apply a colored photosensitive resin composition to a substrate, dry it, and then cure it by selectively irradiating it with ultraviolet rays, and then develop only the uncured parts with an alkaline solution or the like. The mainstream is a photolithography method in which patterns are formed by removal. This permanent mask resist has the role of preventing solder from adhering to unnecessary portions of the conductor layer of the printed wiring board during the flip-chip mounting process of semiconductor elements on the printed wiring board via solder. Furthermore, the permanent mask resist also has the role of preventing corrosion of conductor layers and maintaining electrical insulation between conductor layers when a printed wiring board is used.

Conventionally, permanent mask resists used in the production of printed wiring boards have been produced by screen printing, roll coating, or the like using thermosetting or photosensitive resin compositions.

For example, in flexible wiring boards using mounting methods such as FC (Flip Chip), TAB (Tape Automated Bonding), and COF (Chip On Film), the connection wiring pattern part with the rigid wiring board, IC chip, electronic component, or LCD panel is Other than that, a thermosetting resin paste is screen printed and thermally cured to form a permanent mask resist (for example, see Patent Document 1).

In addition, in recent years, as printed wiring boards have become thinner and more dense, permanent mask resists are required to have low stress, high insulation reliability, and toughness.

Japanese Patent Application Publication No. 2003-198105

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

In order to achieve the above object, the inventors have repeatedly studied the properties and composition of solder resists and found that a photosensitive resin composition using an acid-modified vinyl group-containing epoxy resin has a high elastic modulus and low stress. By applying the resin composition, using an inorganic filler whose surface is treated with a silane coupling agent containing an amino group, and further containing a specific amount of the inorganic filler and a curing agent, it can be used as a permanent mask resist. It was discovered that a cured product with low stress, high insulation reliability, and toughness can be obtained, and the present invention was completed. That is, the present invention provides the following photosensitive resin composition, a patterned 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: (D) an inorganic filler whose surface is treated with a silane coupling agent having an amino group.

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

[3] A patterned cured film having a cured film formed in a pattern using the photosensitive resin composition according to [1] or [2] above.
[4] Step of applying and drying the photosensitive resin composition described in [1] or [2] above on a substrate to form a coating film, and irradiating the coating film with active light and exposing it in a pattern. A method for producing a patterned cured film, comprising: a step of removing unexposed areas by development to obtain a patterned resin film; and a step of curing the patterned resin film.

[5] A photosensitive element comprising a support and the photosensitive resin composition described in [1] or [2] above as a photosensitive layer on the support.
[6] A printed wiring board comprising a permanent mask resist formed using the photosensitive resin composition according to [1] or [2] above, or the photosensitive element according to [5] above.
[7] A step of forming a photosensitive layer on a substrate using the photosensitive resin composition described in [1] or [2] above, or the photosensitive element described in [5] above; A method for manufacturing a printed wiring board, comprising, in order, a step of forming a resist pattern using a 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 that is a printed wiring board equipped with a permanent mask resist and has low stress and high insulation reliability and toughness.

Hereinafter, preferred embodiments of the present invention will be described in detail.
[Photosensitive resin composition]
First, a photosensitive resin composition according to a preferred embodiment of the present invention will be described. In addition, in this specification, (meth)acrylic acid means acrylic acid and methacrylic acid corresponding to it, (meth)acrylate means acrylate and methacrylate corresponding to it, and (meth)acryloyl group means acryloyl group and the corresponding methacryloyl group, and (meth)acryloxy group means an acryloxy group and the corresponding methacryloxy 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) Contains an inorganic filler and (E) a curing agent (hereinafter sometimes simply referred to as (A) component, (B) component, (C) component, (D) component, (E) component, etc.) .

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

The acid-modified vinyl group-containing epoxy resin (A) used in the present invention has a structural unit represented by the following general formula (1) from the viewpoint of being alkaline developable and having excellent resolution and adhesive properties. (e.g., a novolac epoxy resin represented by the following general formula (1')), a bisphenol novolac epoxy resin having a structural unit represented by the following general formula (2), and a novolak epoxy resin having the following general formula (2). 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) and 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 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 the hydrogen atom to the 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 ^R11s and ^Y1s may be the same or different, but at least one ^Y1 represents a glycidyl group. ]

In the epoxy resin having the 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 to glycidyl groups (hydrogen atom/glycidyl group) is 0/100 to 30/70, preferably 0/100 to 10/90.

The number of structural units of the structural unit represented by the general formula (1) in one molecule of the epoxy resin (a) and the number of structural units represented by n1 in the general formula (1') are 1 The number is preferably 10 to 200, more preferably 30 to 150, and still more preferably 30 to 100.
Here, the number of structural units of the structural unit indicates an integer value when the epoxy resin (a) consists of a single type of molecule, and indicates a rational number that is an average value when it is an aggregate of multiple types of molecules. . The same applies to the number of structural units below.

[In general formula (2), two R ^12s each independently represent a hydrogen atom or a methyl group, and two Y ^2s each independently represent a hydrogen atom or a glycidyl group. Note that two R ^12s may be the same or different, and two Y ² may be the same or different. However, at least one of Y ² represents a glycidyl group. ]

The number of structural units of the structural unit in one molecule of the epoxy resin (a) having the structural unit represented by the general formula (2) is 1 or more, and the number of structural units is 1 or more, and the adhesion with the copper substrate, heat resistance, and electrical From the viewpoint of improving insulation, it is preferably 10 to 100, more preferably 15 to 80, even more preferably 15 to 70.

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

The number of structural units of the structural unit in one molecule of the epoxy resin (a) having the structural unit represented by the general formula (3) is 1 or more, and the number of structural units is 1 or more, and the adhesion with the copper substrate, heat resistance, and electrical properties are improved. From the viewpoint of improving insulation, it is preferably 10 to 100, more preferably 15 to 80, and still more preferably 15 to 70.

As the epoxy resin (a), a novolac type epoxy resin having a structural unit represented by the above general formula (1), for example, a novolak type epoxy resin having a structural unit represented by the above general formula (1), from the viewpoint of having excellent process tolerance and improving solvent resistance, is recommended. A novolak type epoxy resin represented by ') is preferred.

Examples of the novolak epoxy resin having a structural unit represented by the general formula (1) include phenol novolak epoxy resins and cresol novolak epoxy resins. These novolak-type epoxy resins can be obtained, for example, by reacting a phenol novolak resin, a cresol novolak resin, and 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. If the reaction temperature is less than 50°C, the reaction will be slow, and if the reaction temperature is 120°C, many side reactions will 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, YDPN -602 (manufactured by Nippon Steel Epoxy Manufacturing Co., Ltd., trade name), DEN-431, DEN-439 (manufactured by Dow Chemical Company, trade name), EOCN-120, EOCN-102S, EOCN-103S, EOCN- 104S, EOCN-1012, EOCN-1025, EOCN-1027, BREN (product names manufactured by Nippon Kayaku Co., Ltd.), EPN-1138, EPN-1235, EPN-1299 (product names manufactured by BASF Japan Co., Ltd.) ), N-730, N-770, N-865, N-870, N-665, N-673, VH-4150, VH-4240 (manufactured by DIC Corporation, product names) are commercially available. It is possible.

In addition to the epoxy resin having the structural unit represented by the general formula (1) above, the epoxy resin (a) can also be used to further reduce the warpage of thin film substrates, as well as thermal shock resistance (during temperature cycle tests). A bisphenol novolac type epoxy resin having a structural unit represented by the above general formula (2) and/or the above general formula (3) may be used from the viewpoint of further improving the crack resistance).

As a bisphenol novolac type epoxy resin having a structural unit represented by the above general formula (3 ^{) ,} for example, the EXA-7376 series (manufactured by DIC Corporation, product name: ), EPON SU8 series (manufactured by Mitsubishi Chemical Corporation, 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) include acrylic acid, a dimer of acrylic acid, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, α- Acrylic acid derivatives such as cyanocinnamic acid, half-ester compounds that are reaction products of hydroxyl group-containing acrylates and dibasic acid anhydrides, vinyl group-containing monoglycidyl ethers, or vinyl group-containing monoglycidyl esters and dibasic acid anhydrides. Examples include half-ester compounds that are reaction products of The vinyl group-containing monocarboxylic acid (b) can be used alone or in combination of two or more.

The half-ester compound is 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 above half-ester compound include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, and hydroxybutyl acrylate. , hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol pentaacrylate, pentaerythritol pentamethacrylate, Examples include glycidyl acrylate and glycidyl methacrylate.

As the dibasic acid anhydride used in the synthesis of the above-mentioned half-ester compound, those containing a saturated group or those 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. acid, ethylhexahydrophthalic anhydride, itaconic anhydride, and the like.

In the above-mentioned reaction between the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b), the vinyl group-containing monocarboxylic acid (b) is preferably used in an amount of 0 to 1 equivalent of the epoxy group in 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. Furthermore, it is particularly preferable to carry out the reaction at a ratio of 0.8 to 1.0 equivalents.

The epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b) can be dissolved in an organic solvent and reacted. Examples of organic solvents 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, propylene glycol monomethyl ether, Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, aliphatic carbonization such as octane, decane, etc. Examples include petroleum solvents such as hydrogen, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

Furthermore, it is preferable to use a catalyst to promote the reaction. As the catalyst, for example, triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylmethylammonium iodide, triphenylphosphine, etc. can be used. The amount of the catalyst used is preferably 0.1 to 10 parts by weight based on the total of 100 parts by weight 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, and pyrogallol. The amount of the polymerization inhibitor used is preferably 0.01 to 1 part by weight based on the total of 100 parts by weight of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b). Further, the reaction temperature is preferably 60 to 150°C, more preferably 80 to 120°C.

In addition, if necessary, a vinyl group-containing monocarboxylic acid (b), a phenolic compound such as p-hydroxyphenethyl alcohol, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, biphenyltetracarboxylic acid Polybasic acid anhydrides such as anhydrides can be used in combination.

In this way, the resin (A') obtained by reacting the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b) is obtained by reacting the glycidyl group of the epoxy resin (a) with the vinyl group-containing monocarboxylic acid (b). ) is presumed to have a hydroxyl group formed by an addition reaction with a carboxyl group.

(A) The aforementioned resin (A'') used as one embodiment of the acid-modified vinyl group-containing epoxy resin is obtained by adding a saturated or unsaturated group-containing polybasic acid anhydride ( c) (hereinafter sometimes simply referred to as polybasic acid anhydride (c)). In the resin (A'') obtained in this way, the resin (A') The hydroxyl group (including the hydroxyl group originally present in the epoxy resin (a)) and the acid anhydride group of the polybasic acid anhydride (c) are half-esterified, resulting in an acid-modified vinyl group-containing epoxy resin. It is presumed 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, hexahydrophthalic anhydride, Examples 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), 0.1 to 1.0 equivalent of the polybasic acid anhydride (c) is added to 1 equivalent of hydroxyl group in the resin (A'). By reacting, the acid value of the acid-modified vinyl group-containing epoxy resin can be adjusted.

(A) The acid value of the acid-modified vinyl group-containing epoxy resin 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 properties of the cured film tend to decrease.

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

Further, if necessary, as the epoxy resin (a), for example, a hydrogenated bisphenol A type epoxy resin can be partially used in combination. Furthermore, as the acid-modified vinyl group-containing epoxy resin (A), a styrene-maleic acid type 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 resin can also be used in combination.

[(A) Molecular weight of acid-modified vinyl group-containing epoxy resin]
The weight average molecular weight of component (A) acid-modified vinyl group-containing epoxy resin is preferably 3,000 to 30,000, more preferably 4 ,000 to 25,000, particularly preferably 5,000 to 18,000. Here, the weight average molecular weight is a weight average molecular weight in terms of polyethylene, which is measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent. More specifically, for example, the weight average molecular weight can be determined by measuring with the following GPC measurement device and measurement conditions and converting it using a standard polystyrene calibration curve. In addition, to create a calibration curve, a set of 5 samples ("PStQuick MP-H" and "PStQuick B", manufactured by Tosoh Corporation) is used as standard polystyrene.
[GPC measurement 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), manufactured by Tosoh Corporation Company-made [Measurement conditions]
Solvent: Tetrahydrofuran (THF)
Measurement temperature: 40℃
Flow rate: 0.35ml/min Sample concentration: 10mg/THF5ml
Injection volume: 20μl

[(A) Content of acid-modified vinyl group-containing epoxy resin]
In the photosensitive resin composition of the present invention, the content of the acid-modified vinyl group-containing epoxy resin (A) is preferably 5 to 60% by mass, based on the total solid content of the photosensitive resin composition, and 10% by mass. It is more preferably 15 to 40% by weight, and particularly preferably 15 to 40% by weight. When the content of component (A) is within the above range, a coating film with better heat resistance, electrical properties, and chemical resistance can be obtained.

<(B) Photopolymerizable compound having an ethylenically unsaturated bond>
As the photopolymerizable compound (B) 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; glycol mono- or di(meth)acrylates such as ethylene glycol, methoxytetraethylene glycol, and polyethylene glycol; (Meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N-methylol(meth)acrylamide; aminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate; hexanediol; Polyhydric alcohols such as methylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, tris-hydroxyethyl isocyanurate, or their ethylene oxide or propylene oxide adducts, polyhydric (meth)acrylates, phenoxyethyl (meth)acrylate , (meth)acrylates of ethylene oxide or propylene oxide adducts of phenols such as polyethoxydi(meth)acrylate of bisphenol A, glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, etc. Examples include meth)acrylates, melamine (meth)acrylate, acrylamide, acrylonitrile, diacetone acrylamide, styrene, vinyltoluene, and the like. Moreover, it is more preferable to have three or more ethylenic bonds in one molecule in order to increase the crosslinking density by photocuring and improve heat resistance and insulation reliability. Examples of compounds having such an ethylenically unsaturated bond include dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and the like. These (B) compounds having an ethylenically unsaturated group may be 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 solid content in the photosensitive resin composition. More preferably, it is 3 to 20% by mass. When the content is 2% by mass or more, the tendency of exposed areas to dissolve during development due to low photosensitivity can be suppressed, and when the content is 50% by mass or less, a decrease in heat resistance can be suppressed.

<(C) Photopolymerization initiator>
Examples of the photopolymerization initiator (C) 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, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-methyl -1-[4-(Methylthio)phenyl]-2-morpholino-1-propanone, acetophenones such as N,N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1 -Anthraquinones such as chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; Thioxanthone such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; acetophenone dimethyl Ketals such as ketal and benzyl dimethyl ketal; benzophenones such as benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis(diethylamino)benzophenone, Michler's ketone, and 4-benzoyl-4'-methyldiphenyl sulfide ;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 and 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer Imidazole dimers, acridines such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)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-carbazol-3-yl] Examples include oxime esters such as ethanone 1-(O-acetyloxime) and 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl)oxime]. These photopolymerization initiators (C) can 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 (for example, Irgacure 819 manufactured by BASF Japan Co., Ltd.), which has good bottom hardening properties due to photobleaching, is used. It is preferable to use 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (for example, Irgacure 369 manufactured by BASF Japan Co., Ltd.), which does not easily evaporate and therefore does not easily generate outgas. .

Furthermore, (C') The photopolymerization initiation aids can be used alone or in combination of two or more.

[(C) Content of photopolymerization initiator]
The content of the photopolymerization initiator (C) in the photosensitive resin composition of the present invention is preferably 0.2 to 20% by mass, more preferably 0.2% by mass, based on the total solid content of the photosensitive resin composition. The amount is 4 to 15% by weight, more preferably 0.6 to 10% by weight. Further, when the content of the photopolymerization initiator (C) is 0.2% by mass or more, the exposed area becomes difficult to dissolve during development, and when the content is 20% by mass or less, a decrease in heat resistance can be suppressed.

<(D) Inorganic filler>
Examples of the inorganic filler (D) used in the photosensitive resin composition of the present invention include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), titania (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), Zirconia (ZrO ₂ ), silicon nitride (Si ₃ N ₄ ), barium titanate (BaO・TiO ₂ ), barium carbonate (BaCO ₃ ), magnesium carbonate, aluminum oxide, aluminum hydroxide, magnesium hydroxide, lead titanate ( PbO・TiO ₂ ), lead zirconate titanate (PZT), lanthanum lead zirconate titanate (PLZT), gallium oxide (Ga ₂ O ₃ ), spinel (MgO・Al ₂ O ₃ ), mullite (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 inorganic fillers (D) can be used alone or in combination of two or more.

In order to disperse the inorganic filler (D) used in the photosensitive resin composition of the present invention in the resin without agglomerating while maintaining the primary particle size, it is practical to use one that has been surface-treated with a silane coupling agent. It is. As the silane coupling agent, commonly available ones can be used, such as alkylsilanes, alkoxysilanes, vinylsilanes, epoxysilanes, aminosilanes, acrylicsilanes, methacrylsilanes, mercaptosilanes, sulfidesilanes, isocyanatesilanes, Sulfur silane, styryl silane, alkylchlorosilane, etc. can be used. Specific compound names include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, diisopropyldimethoxysilane, and isobutyltrimethoxysilane. Silane, diisobutyldimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, 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, vinyltrisulfide 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, and γ-isocyanatepropyltriethoxysilane. Preferred silane coupling agents to be used are those that react with components contained in the photosensitive resin composition, such as (A) epoxysilane that reacts with carboxylic groups in acid-modified vinyl group-containing epoxy resins; Acrylic silane, methacryl silane, or an amino group that reacts with an epoxy group or forms a hydrogen bond with a hydroxyl group is preferred. Further, mercaptosilane and isocyanate silane may be used, and these silanes react with the ethylenically unsaturated group of the photopolymerizable monomer (B) having an ethylenically unsaturated bond, and the silane coupling agent is used. It is thought that it will have the same effect as when. Among the above silane coupling agents, silane coupling agents containing amino groups have high reactivity with the epoxy group-containing resin contained in the photosensitive resin composition, and in addition, have the effect of strengthening the bond between silica and resin. Because of its high resistance, it can strengthen the strength and toughness of the film when used as a permanent mask resist, contributing to improved insulation reliability in high-temperature and high-humidity tests and crack resistance in temperature cycle tests. Particularly useful in embodiments. Among the silane compounds listed above, phenylaminosilanes such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-phenylaminopropyltrimethoxysilane are used as the silane coupling agent containing an amino group. It is preferable to use it because the effects of the present invention can be obtained most effectively.

(D) Among the inorganic fillers, 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 soldering heat resistance, HAST property (insulation reliability), crack resistance (thermal shock 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 agglomeration prevention effect.

(D) The average particle size of the inorganic filler 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 that there be. Further, the maximum particle diameter of the inorganic filler (D) is preferably 0.1 to 5 μm, more preferably 0.1 to 3 μm, and particularly preferably 0.1 to 1 μm. When the maximum particle diameter exceeds 5 μm, 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 inorganic filler (D) surface-treated with a coupling agent having an amino group is determined from the viewpoint of resolution and low coefficient of thermal expansion in the solid state of the photosensitive resin composition. The amount is 30 to 60% by weight, preferably 30 to 55% by weight, and more preferably 35 to 50% by weight, based on the total amount. When the content of the inorganic filler (D) is within these ranges, low coefficient of thermal expansion, heat resistance, insulation reliability, thermal shock resistance, resolution, film strength, etc. can be further improved. When 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 will not be lowered, the stress will be insufficiently lowered, and there is a tendency that it will be impossible to reduce warpage. Furthermore, crack resistance during reflow mounting tends to be difficult to obtain.

<(E) Curing agent>
(E) The curing agent used in the photosensitive resin composition of the present invention is a compound that itself is cured by heat, ultraviolet rays, etc., or (A) a carboxyl group or hydroxyl group of an acid-modified vinyl group-containing epoxy resin and heat, Compounds that cure by reacting with ultraviolet light or the like are preferred. (E) By using the curing agent, it is possible to improve the heat resistance, adhesion to the underfill material and substrate, chemical resistance, etc. of the cured film formed from the photosensitive resin composition.

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

(E) The curing agent is cured by reacting with carboxyl groups, hydroxyl groups, and glycidyl groups using heat, ultraviolet rays, etc., from the viewpoint of further improving the heat resistance of the cured film and the adhesion with underfill materials and substrates. It is preferable to contain a compound as an essential component. Examples of such compounds include the above-mentioned melamine compounds. It is particularly preferable to contain the above-mentioned melamine compound in combination with an epoxy resin.

Further, (E) the curing agent 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. You may use it together.

As the blocked 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, phenylene diisocyanate, naphthylene diisocyanate, bis(isocyanatemethyl)cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, and the like. and their adducts, biurets and isocyanurates.

Examples of isocyanate blocking agents include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol, and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-parerolactam, 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 formaldehydoxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monoxime, and cyclohexane oxime. ; Mercaptan blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol, ethylthiophenol; Acid amide blocking agents such as acetamide and benzamide; Imides such as succinimide and maleic imide Amine-based blocking agents such as xylidine, aniline, butylamine and dibutylamine; imidazole-based blocking agents such as imidazole and 2-ethylimidazole; and imine-based blocking agents such as methyleneimine and propyleneimine.

[(E) Content of curing agent]
(E) The curing agent may be used alone or in combination of two or more. (E) The content of the curing agent 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 preferred. (E) By controlling the content of the curing agent within the range of 2 to 40% by mass, while maintaining good developability, the heat resistance of the cured film to be formed is further improved, and it can be used as a permanent mask resist. Peeling between the substrates can be prevented.

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

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

<Other ingredients>
In addition to the above-mentioned components (A) to (E), the photosensitive resin composition of the present invention may optionally contain (F) a pigment, (G) an elastomer, (H) an epoxy resin curing agent, and (I) a thermal It may further contain a plastic resin, (J) other additives, and the like. Each component will be explained below.

<(F) Pigment>
The photosensitive resin composition of the present invention preferably contains (F) a pigment in order to improve the identifiability and appearance of the manufacturing equipment. (F) The pigment is preferably used depending on the desired color when hiding wiring or the like. (F) As the pigment, a coloring agent that develops a desired color may be appropriately selected and used, such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black. Preferred examples include known colorants such as.

[(F) Pigment content]
(F) When using a pigment, the content of the (F) pigment is preferably 0.1 to 10% by mass, based on the total solid content in the photosensitive resin composition, from the viewpoint of further hiding the wiring. More preferably 0.1 to 5% by weight, particularly preferably 0.5 to 3% by weight.

<(G) Elastomer>
Moreover, it is preferable that the photosensitive resin composition of this invention further contains (G) elastomer. (G) By containing an elastomer, the stress of the cured film formed from the photosensitive resin composition can be reduced, and flexibility and adhesion with the underfill material and the substrate can be further improved. . That is, when the cross-linking reaction (curing reaction) progresses in the photosensitive resin composition of the present invention due to ultraviolet rays or heat, (A) the acid-modified vinyl group-containing epoxy resin cures and shrinks, causing distortion (internal distortion) inside the resin. The problem of deterioration of flexibility and adhesiveness due to stress) can be solved by adding (G) elastomer.

Examples of the elastomer (G) include styrene elastomer, olefin elastomer, urethane elastomer, polyester elastomer, polyamide elastomer, acrylic elastomer, and silicone elastomer. 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 elastomer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene block copolymer, and the like.

In addition to styrene, styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene can be used as components constituting the styrene-based elastomer. More specifically, the examples include Tuffprene, Solprene T, Asaprene T, Tuftec (trade name, manufactured by Asahi Kasei Corporation), Elastomer AR (trade name, manufactured by Aron Kasei Corporation), Clayton G, Cauliflex (trade name, manufactured by Shell Japan). Co., Ltd., product name), JSR-TR, TSR-SIS, Dynaron (manufactured by JSR Co., Ltd., product name), Denka STR (manufactured by Denka Co., Ltd., product name), Quintac (manufactured by Nippon Zeon Co., Ltd., (Product name), TPE-SB series (Product name, manufactured by Sumitomo Chemical Co., Ltd.), Lavalon (Product name, manufactured by Mitsubishi Chemical Co., Ltd.), Septon, Hybrur (Product name, manufactured by Kuraray Co., Ltd.), Sumiflex (Product name, manufactured by Sumitomo Chemical Co., Ltd.) Bakelite Co., Ltd., trade name), Rheostomer, Actimer (manufactured by RIKEN TECHNOS Co., Ltd., trade name), etc. can be used.

Olefin elastomers are copolymers of α-olefins having 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, and 4-methyl-pentene. Specific examples include ethylene-propylene copolymer (EPR), ethylene-propylene-diene copolymer (EPDM), dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, butadiene, Examples include a copolymer of a non-conjugated diene having 2 to 20 carbon atoms such as isoprene and an α-olefin, and a carboxy-modified NBR obtained by copolymerizing methacrylic acid with a butadiene-acrylonitrile copolymer. More specifically, ethylene/α-olefin copolymer rubber, ethylene/α-olefin/non-conjugated diene copolymer rubber, propylene/α-olefin copolymer rubber, and butene/α-olefin copolymer rubber are used. Can be mentioned. Furthermore, specifically, Milastomer (manufactured by Mitsui Chemicals, Inc., trade name), EXACT (manufactured by ExxonMobil, Inc., trade name), ENGAGE (manufactured by Dow Chemical Corporation), hydrogenated styrene-butadiene rubber "DYNABON HSBR" ( (manufactured by JSR Corporation, trade name), butadiene-acrylonitrile copolymer "NBR series" (manufactured by JSR Corporation, trade name), or butadiene-acrylonitrile copolymer "XER series" (manufactured by JSR Corporation) modified with carboxyl groups at both terminals. BF-1000 (manufactured by Nippon Soda Co., Ltd., trade name), PB-3600 (manufactured by Daicel Corporation, trade name), etc., which are epoxidized polybutadiene obtained by partially epoxidizing polybutadiene, can be used. can.

Urethane elastomers are composed of structural units of hard segments made of low-molecular glycols and diisocyanates, and soft segments made of high-molecular (long-chain) diols and diisocyanates.

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

Specific examples of urethane-based elastomers 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 polyester elastomers include those obtained by polycondensing dicarboxylic acids or derivatives thereof and diol compounds or derivatives thereof.

Specific examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid, and aromatic dicarboxylic acids in which the hydrogen atoms of these aromatic nuclei are substituted with methyl groups, ethyl groups, phenyl groups, etc. Examples 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 can be used alone or in combination of two or more.

Specific examples of diol compounds include fatty acids 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, alicyclic diols, and dihydric 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 -, R ²¹ and R ²² each independently represents a halogen atom or an alkyl group having 1 to 12 carbon atoms, and p and q each independently represent 0.
Indicates an integer of ~4, and r indicates 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 resorcinol. These compounds can be used alone or in combination of two or more.

Furthermore, a multi-block copolymer can be used in which an aromatic polyester (eg, polybutylene terephthalate) portion is used as a hard segment component and an aliphatic polyester (eg, polytetramethylene glycol) portion is used as a soft segment component. There are various grades depending on the type, ratio, and molecular weight of hard and soft segments. Specific examples include Hytrel (manufactured by DuPont-Toray Co., Ltd., trade name), Pelprene (manufactured by Toyobo Co., Ltd., trade name), Espel (manufactured by Hitachi Chemical Co., Ltd., trade name), and the like.

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

As the polyamide, polyamide-6, polyamide-11, polyamide-12, etc. can be used. As the polyether, polyoxyethylene, polyoxypropylene, polytetramethylene glycol, etc. can be used. Specifically, UBE polyamide elastomer (manufactured by Ube Industries, Ltd., trade name), Diaamide (manufactured by Daicel Evonik, trade name), PEBAX (manufactured by Toray Industries, Ltd., trade name), Grillon ELY (manufactured by M Chemie Japan Ltd.) Nopamid (manufactured by Mitsubishi Chemical Corporation, trade name), Glylax (manufactured by DIC Corporation, trade name), etc. can be used.

As the acrylic elastomer, acrylic ester is used as a main component, and ethyl acrylate, butyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, etc. are used. Further, as the crosslinking point monomer, glycidyl methacrylate, allyl glycidyl ether, etc. can be used. Furthermore, acrylonitrile and ethylene can also be copolymerized. Specifically, acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer, etc. can be used.

Silicone-based elastomers, for example, have organopolysiloxane as a main component and can be divided into polydimethylsiloxane-based, polymethylphenylsiloxane-based, and polydiphenylsiloxane-based. Some are partially modified with vinyl groups, alkoxy groups, etc. Specific examples include the KE series (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), the SE series, the CY series, the SH series (trade names, manufactured by Dow Corning Toray Industries, Inc.), and the like.

Furthermore, in addition to the above-mentioned elastomers, rubber-modified epoxy resins can also be used. Rubber-modified epoxy resins include, for example, bisphenol F-type epoxy resins, bisphenol A-type epoxy resins, salicylaldehyde-type epoxy resins, phenol novolac-type epoxy resins, or cresol novolac-type epoxy resins in which both part or all of the epoxy groups are combined. It can be obtained by modification with terminal carboxylic acid-modified butadiene-acrylonitrile rubber, terminal amino-modified silicone rubber, etc. Among these elastomers, Espel (manufactured by Hitachi Chemical Co., Ltd., Espel 1612, 1620, trade name), which is a polyester elastomer having a butadiene-acrylonitrile copolymer modified with carboxyl groups at both terminals and a hydroxyl group, has excellent shear adhesive properties. , epoxidized polybutadiene, etc. are preferred. Further, elastomers that are liquid at room temperature are particularly preferred.

[(G) Elastomer content]
(G) When using an elastomer, its content 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, and 3% by mass. It is particularly preferred that the amount is 10% by mass. (G) By controlling the content of elastomer within the range of 1 to 20% by mass, it is possible to further improve thermal shock resistance and adhesive strength between the underfill material and the cured film while maintaining good developability. can. Furthermore, when used in a thin film substrate, the warpage of the thin film substrate can be reduced.

<(H) Epoxy resin curing agent>
(H) An epoxy resin curing agent can also 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 formed. .

Specific examples of such (H) epoxy resin curing agents include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, 2-phenyl-4- Imidazole derivatives such as methyl-5-hydroxymethylimidazole; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, polybasic hydrazide Polyamines such as; organic acid salts and/or epoxy adducts of these; amine complexes of boron trifluoride; trimethylamine, triethanolamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine , hexa(N-methyl)melamine, 2,4,6-tris(dimethylaminophenol), tetramethylguanidine, m-aminophenol and other tertiary amines; polyvinylphenol, polyvinylphenol bromide, phenol novolak, alkylphenol novolak polyphenols such as; organic phosphines such as tributylphosphine, triphenylphosphine, and tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl(2,5-dihydroxyphenyl)phosphonium bromide and hexadecyltributylphosphine chloride; ; Quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; Polybasic acid anhydrides mentioned above; Diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrylium Examples include hexafluorophosphate. These (H) epoxy resin curing agents may be used alone or in combination of two or more.

[(H) Content of epoxy resin curing agent]
(H) When using an epoxy resin curing agent, its content is preferably 0.01 to 20% by mass, and 0.1 to 10% by mass, based on the total solid content of the photosensitive resin composition. It is more preferable that there be.

<(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.

(I) Examples of the thermoplastic resin include acrylic resin and urethane resin. (I) When containing a thermoplastic resin, 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>
Furthermore, the photosensitive resin composition of the present invention may optionally contain organic fine particles such as melamine and organic bentonite, polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol, bentone, and montmorillonite. Various known and commonly used additives such as thickeners, silicone-based, fluorine-based, and vinyl resin-based antifoaming agents, 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 phosphorous compounds, aromatic condensed phosphate esters, halogen-containing condensed phosphate esters, etc. can also be added.

As the diluent, for example, an organic solvent can be used. Examples of organic solvents 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, propylene glycol monomethyl ether, Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, aliphatic carbonization such as octane, decane, etc. Examples include petroleum solvents such as hydrogen, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. The diluent may be used alone or in combination of two or more. When using a diluent, the content can be adjusted as appropriate from the viewpoint of coating properties of the photosensitive resin composition.

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

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

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

That is, the coating is applied to a substrate such as a copper-clad laminate to a film thickness of 10 to 200 μm by a screen printing method, a spray method, a roll coating method, a curtain coating method, an electrostatic coating method, etc., and then a coating film of 60 μm is applied. After drying at ~110°C, the negative film is brought into direct contact (or non-contacted through a transparent film) and activated light (e.g. ultraviolet light) is applied at an exposure dose of preferably 10 to 1,000 mJ/ ^cm2. irradiation, and then the unexposed areas are dissolved and removed (developed) with a dilute alkaline aqueous solution or an organic solvent to obtain a patterned resin film. Next, the exposed portion of the patterned resin film is sufficiently cured by post-exposure (ultraviolet light exposure) and/or post-heating to obtain a cured film. Post-exposure is preferably carried out at an exposure dose of, for example, 1 to 5 J/cm ² , and post-heating is preferably carried out at 100 to 200° C. for 30 minutes to 12 hours.

<Photosensitive element>
Furthermore, the photosensitive resin composition of the present invention can be laminated onto a support to form a photosensitive element. The photosensitive element of the present invention has, for example, a support and a photosensitive layer formed using the photosensitive resin composition of the present invention on the support. 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 coating a solution of the photosensitive resin composition on a support and drying it.
The coating film can be dried using hot air drying, a dryer using far infrared rays, or near infrared rays, and the drying temperature is, for example, preferably 60 to 120°C, more preferably 70 to 110°C, More preferably, the temperature is 80 to 100°C. Further, the drying time is, for example, preferably 1 to 60 minutes, more preferably 2 to 30 minutes, and still more preferably 5 to 20 minutes.

Further, in the photosensitive element of the present invention, a protective layer can also 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 wiring board>
The printed wiring board of the present invention includes a permanent mask resist formed from 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 substrates and underfill materials, so it can be easily removed from the permanent mask resist and printed circuit boards. A printed wiring board free from warpage can be obtained.

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

EXAMPLES 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 (trade name: EXA-7376, manufactured by DIC Corporation, epoxy equivalent: 186) having the structural unit represented by the above general formula (3) (R ¹³ = hydrogen atom, Y ³ = glycidyl group) ), 70 parts by mass of acrylic acid, 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate were heated to 90° C. and stirred to react, and the mixture was completely dissolved. 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 to react until the acid value of the solution became 1 mgKOH/g. A solution was obtained containing: 98 parts by mass of tetrahydrophthalic anhydride (THPAC) and 85 parts by mass of carbitol acetate were added to the solution after the reaction, heated to 80°C, reacted for about 6 hours, and then cooled until the solid content concentration was 73 parts by mass. % of THPAC-modified bisphenol F-type novolak epoxy acrylate (hereinafter referred to as "acid-modified vinyl group-containing epoxy resin (A-1)" as component (A). Acid value: 75 mgKOH/g, weight average molecular weight: 10,000). A solution was obtained.

(Examples 1 to 3, Comparative Examples 1 to 3)
After compounding each material shown in Table 1 below in the amount shown in the same table (unit: parts by mass), kneading with a three-roll mill, and adding carbitol acetate so that the solid content concentration was 70% by mass. A photosensitive resin composition was obtained. The amount of each material in Table 1 below indicates the amount of 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 novolac epoxy acrylate prepared in Synthesis Example 1 *2 (Aronix M402): Dipentaerythritol hexaacrylate (manufactured by Toagosei Co., Ltd., Product name)
*3 (Irgacure 369): 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (manufactured by BASF Japan Co., Ltd., trade name)
*4 (SFP-20M): Silica fine particles (manufactured by Denka Co., Ltd., trade 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 & Material Co., Ltd., product name)
*7 (RE-306): Epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name),
*8 (PB-3600): Epoxidized polybutadiene (manufactured by Daicel Corporation, product name)

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

[Warpage of board]
The photosensitive resin compositions of Examples and Comparative Examples were screen printed on copper-clad laminate substrates (E-700G, manufactured by Hitachi Chemical Co., Ltd.) with a size of 74 mm x 240 mm 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 dryer. The surface of the obtained coating film was irradiated with ultraviolet rays in a pattern at a cumulative exposure dose of 100 mJ/cm ² and developed for 60 seconds with a 1% by mass aqueous sodium carbonate solution to form a resist cured film. Next, it was exposed to light using an ultraviolet exposure device at an exposure dose of 2000 mJ/cm ² and heated at 170° C. for 1 hour to prepare a test piece. The warp of the substrate was determined from the four corners of the board where the warp was the greatest, and was evaluated as "x" if it was 2 mm or more, and "○" if it was 2 mm or less. The evaluation results are shown in Table 2.

[Insulation reliability]
A comb-shaped electrode with lines/spaces of 20 μm/20 μm was formed by etching the copper surface of a printed wiring board substrate (E-679, manufactured by Hitachi Chemical Co., Ltd., trade name) in which a 12 μm thick copper foil was laminated on a glass epoxy base material. was formed. This substrate was used as an evaluation substrate, and a cured resist was formed on the substrate as described above, and then exposed to conditions of 135° C., 85%, and 5 V for 200 hours. Thereafter, the degree of occurrence of migration was observed using a metallurgical microscope with a magnification of 100 times, and evaluated based on 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 significant migration occurred and the resistance value decreased were evaluated as "x".
[Crack resistance]
A cured resist was formed as described above on the copper surface of a printed wiring board substrate (E-679, manufactured by Hitachi Chemical 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 applied by setting cycles of 155° C./30 minutes and 155° C./30 minutes, and after 1000 cycles, visual observation and microscopic observation were performed. No cracks were observed as ``○'', and cracks were observed as ``x''.

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

Claims (14)

(A) 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 containing a melamine compound. A photosensitive resin composition comprising: (D) an inorganic filler whose surface is treated with a silane coupling agent having an amino group. The content of the inorganic filler (D) is 30 to 60% by mass of the total solid content in the photosensitive resin composition, and the content of the curing agent (E) is the acid-modified vinyl group (A). 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. The acid-modified vinyl group-containing epoxy resin (A) is an acid-modified vinyl group-containing epoxy resin synthesized using a novolak-type epoxy resin having a structural unit represented by the following general formula (1), and an acid-modified vinyl group-containing epoxy resin synthesized using a novolac type epoxy resin having a structural unit represented by the following general formula (1). 2) An acid-modified vinyl group-containing epoxy resin synthesized using a bisphenol novolac type epoxy resin having a structural unit represented by the following formula (3), and a bisphenol novolak type epoxy resin having a structural unit represented by the following general formula (3). The photosensitive resin composition according to claim 1 or 2, containing at least one selected from the group consisting of acid-modified vinyl group-containing epoxy resins synthesized using the photosensitive resin composition.

[In general formula (1), R ¹¹ represents a hydrogen atom or a methyl group, multiple Y ^1s represent a hydrogen atom or a glycidyl group, and the molar ratio of the hydrogen atom to the glycidyl group (hydrogen atom/glycidyl group) is 0/100 to 30/70. ]

[In general formula (2), R ¹² each independently represents a hydrogen atom or a methyl group, Y ² each independently represents a hydrogen atom or a glycidyl group, and the two R ^12s may be the same or different, provided that , Y ² represents a glycidyl group. ]

[In general formula (3), R ¹³ each independently represents a hydrogen atom or a methyl group, Y ³ each independently represents a hydrogen atom or a glycidyl group, two R ^13s may be the same or different, However, at least one of Y ³ represents a glycidyl group. ] The acid-modified vinyl group-containing epoxy resin (A) is a novolak-type epoxy resin having a structural unit represented by the general formula (1), a bisphenol novolac-type epoxy resin 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). The photosensitive resin composition according to claim 3, which is a resin obtained by reacting the resin (A') with a saturated or unsaturated group-containing polybasic acid anhydride (c). Any one 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 curing agent (E) contains an epoxy resin and a melamine compound, and the content of the epoxy resin in the curing agent (E) is 15 to 100 parts by mass per 100 parts by mass of the acid-modified vinyl group-containing epoxy resin (A). The photosensitive resin composition according to claim 5, wherein the content of the melamine compound in the curing agent (E) is 15 to 100 parts by mass per 100 parts by mass of the acid-modified vinyl group-containing epoxy resin (A). thing. According to any one of claims 1 to 6, the photopolymerizable monomer (B) having an ethylenically unsaturated bond is a polyfunctional photopolymerizable monomer having three or more ethylenically unsaturated bonds in one molecule. The photosensitive resin composition described. 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 patterned 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 and drying the photosensitive resin composition according to any one of claims 1 to 9 on a substrate to form a coating film, and a step of irradiating the coating film with active light and exposing it in a pattern. A method for producing a patterned cured film, comprising: a step of removing an unexposed portion by development to obtain a patterned resin film; and a step of curing the patterned resin film. A photosensitive element comprising a support and the photosensitive resin composition according to any one of claims 1 to 9 as a photosensitive layer on the support. A printed wiring board comprising a permanent mask resist formed using the photosensitive resin composition according to any one of claims 1 to 9 or 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, comprising the steps of forming a resist pattern and curing the resist pattern to form a permanent mask resist.