JP7294389B2 - Photosensitive resin composition, photosensitive film using the same, method for forming resist pattern, and printed wiring board - Google Patents

Description

TECHNICAL FIELD The present invention relates to an alkali-developable photosensitive resin composition for a protective film of a printed wiring board, and more particularly to a photosensitive resin composition for a protective film of a printed wiring board, which is used as a permanent mask resist in the field of resists for substrates for semiconductor packages. The present invention relates to a flexible resin composition, a photosensitive film using the same, a method for forming a resist pattern, and a printed wiring board.

BACKGROUND ART In the printed wiring board field, conventionally, a permanent mask resist (protective film) is 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, then cured by selectively irradiating with ultraviolet rays, and then only the uncured portion is developed with an alkaline solution or the like. A photolithography method that removes and forms a pattern is the mainstream. This permanent mask resist has the role of preventing solder from adhering to unnecessary portions of the conductor layer of the printed wiring board, for example, in the process of flip-chip mounting a semiconductor element onto the printed wiring board via solder. there is Furthermore, the permanent mask resist also plays a role of preventing corrosion of the conductor layers and maintaining electrical reliability between the conductor layers when the printed wiring board is used.

Conventionally, permanent mask resists in the manufacture of printed wiring boards have been produced by methods such as screen printing or roll coating of thermosetting or photosensitive resin compositions.

For example, in flexible wiring boards using mounting methods such as FC, TAB, and COF, thermosetting resin paste is screen-printed, except for rigid wiring boards, IC chips, electronic parts or LCD panels, and connection wiring patterns. It is thermally cured to form a permanent mask resist (see, for example, Patent Document 1).

Further, in recent years, with the increasing density of wiring patterns, a permanent mask resist is required to have high resolution, and a photosensitive resin composition that forms a pattern by a photographic method has been actively used. Among them, the alkali developing type, which can be developed with a weakly alkaline aqueous solution such as an aqueous sodium carbonate solution, has become mainstream from the viewpoint of working environment conservation and global environment conservation. In addition, along with the trend of miniaturization and high performance of electronic equipment, there is a marked trend toward higher density due to the narrower pitch of the wiring of semiconductor chips. A flip-chip connection method that joins the This flip chip connection method is a semiconductor mounting method based on a reflow method in which solder balls are placed between a substrate and a semiconductor chip and the whole is heated to melt and bond. As a result, the substrate itself is exposed to a high-temperature environment during solder reflow, and the thermal shrinkage of the substrate generates a large amount of stress on the solder balls that connect the substrate and the semiconductor, causing poor wiring connections and cracks in the permanent mask resist and underfill. ). Therefore, insulating materials used for printed wiring boards are required to have a low coefficient of thermal expansion.

As wiring patterns and insulation patterns (permanent mask resist) on printed wiring boards become more precise, the pitch between wiring lines becomes finer, resulting in excellent electrical reliability between wiring lines (especially after moisture absorption (HAST (High Accelerated Stress Test, highly accelerated life test) resistance)) is required.
In the manufacture thereof, an electroless plating method that does not require lead wires has been adopted (for example, Patent Document 2). The electroless plating method is characterized by uniform plating thickness and high smoothness. However, since the pH of the plating solution is high and strongly alkaline, and the temperature of the solution is set to a high temperature of about 90° C. in order to improve the plating deposition rate, damage to the permanent mask resist tends to increase. Therefore, permanent mask resists are required to be resistant to damage caused by plating solutions used for electroless plating, and to have further improved electroless plating resistance.

In addition, due to the decrease in thermal expansion coefficient, increasing the amount of the inorganic filler tends to cause a phenomenon in which the filler remains after alkali development. Due to the presence of this filler residue, the electrical connection becomes insufficient and the electrical reliability deteriorates, so improvement of the filler residue is required.

Japanese Patent Application Laid-Open No. 2003-198105 JP 2006-190848 A

The present invention has excellent heat resistance, a low coefficient of thermal expansion, further good resolution, electrical reliability (HAST resistance), a photosensitive resin composition that achieves filler developability, and a photosensitive resin composition using the same A film, a method for forming a resist pattern, and a printed wiring board are provided.

The inventors have made repeated studies on solder resist properties and composition that can satisfy these high heat resistance, low coefficient of thermal expansion, good electrical reliability (HAST resistance), good filler developability, and elimination of filler residue. ) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable monomer having an ethylenically unsaturated bond, (C) a photopolymerization initiator, and (D) an inorganic filler, and (A) The acid-modified vinyl group-containing epoxy resin of the component is a specific compound with high heat resistance, and the application of a resin having a degree of dispersion represented by Mw/Mn of 2.0 to 5.0, and the addition of an inorganic filler of 30 to 70 mass. %, heat resistance, electrical reliability, and filler developability (removal of filler residue) can be achieved at the same time without deteriorating the coefficient of linear thermal expansion.

The photosensitive resin composition of the present invention comprises [1] (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable monomer having an ethylenically unsaturated bond, (C) a photopolymerization initiator, and (D) ) is a photosensitive resin composition containing an inorganic filler, and the acid-modified vinyl group-containing epoxy resin of component (A) is a compound represented by general formula (1) or general formula (2) (where Mw/ Mn (weight average molecular weight/number average molecular weight) with a degree of dispersion of 2.0 to 5.0), and (D) the content of the inorganic filler is 30 to 70 mass relative to the total solid content %.

［一般式（１）中、Ｒ^１１は水素原子又はメチル基を示し、Ｙ^１は水素原子又はグリシジル基を示し、ｎ１は１以上の整数を示す。なお、複数存在するＲ^１１及びＹ^１はそれぞれ同一でも異なっていてもよい。但し、少なくとも一つのＹ^１はグリシジル基を示す。一般式（２）中、Ｒ^１２は水素原子又はメチル基を示し、Ｙ^２はそれぞれ独立に水素原子又はグリシジル基を示す。なお、２つのＲ^１２は同一でも異なっていてもよい。但し、Ｙ^２の少なくとも一方はグリシジル基を示す。］

[In general formula (1), R ¹¹ represents a hydrogen atom or a methyl group, Y ¹ represents a hydrogen atom or a glycidyl group, and n1 represents an integer of 1 or more. Plural R ¹¹ and Y ¹ may be the same or different. However, at least one ^Y1 represents a glycidyl group. In general formula (2), R ¹² represents a hydrogen atom or a methyl group, and Y ² each independently represents a hydrogen atom or a glycidyl group. Two R ¹² may be the same or different. However, at least one of Y ² represents a glycidyl group. ]

Further, the photosensitive resin composition of the present invention, [2] (B) a photopolymerizable monomer having an ethylenically unsaturated bond is a polyfunctional photopolymerizable having three or more ethylenically unsaturated bonds in one molecule It is a photosensitive resin composition according to the above [1], which is a monomer.
Moreover, the photosensitive resin composition of the present invention is the photosensitive resin composition according to [3] above [1] or [2], which further contains (E) a pigment.

Further, the photosensitive film of the present invention comprises [4] a support and a photosensitive layer formed from the photosensitive resin composition according to any one of [1] to [3] above.
Further, in the method of forming a resist pattern of the present invention, the above [ A photosensitive layer is laminated using the photosensitive resin composition according to any one of 1] to [3], and a predetermined portion of the photosensitive layer is irradiated with an actinic ray to form an exposed portion. It is characterized by removing the portion other than the exposed portion of the photosensitive layer.
Further, the printed wiring board of the present invention comprises an insulating substrate, a conductor layer having a circuit pattern formed on the insulating substrate, and any one of the above [1] to [3] so as to cover the conductor layer. and a permanent resist layer formed using the photosensitive resin composition described in .

According to the present invention, a photosensitive resin composition for a protective film of a printed wiring board that can achieve both high heat resistance, resolution, electrical reliability (HAST resistance), and filler developability without deteriorating the coefficient of linear thermal expansion, A photosensitive film, a method for forming a resist pattern, and a printed wiring board using this can be provided.

In the present invention, (meth)acrylic acid means acrylic acid or methacrylic acid, (meth)acrylate means acrylate or its corresponding methacrylate, and (meth)acryloyl group means acryloyl group or methacryloyl group. .
Preferred embodiments of the present invention are described in detail below.
First, a photosensitive resin composition according to a preferred embodiment will be described.

[(A) Acid-modified vinyl group-containing epoxy resin]
The (A) acid-modified vinyl group-containing epoxy resin (having a degree of dispersion represented by Mw/Mn of 2.0 to 5.0) used in the present invention will be described.
The (A) acid-modified vinyl group-containing epoxy resin used in the present invention has a degree of dispersion represented by Mw/Mn of 2.0 to 5.0, is capable of alkali development, and is decomposable. A group consisting of novolak-type epoxy resins represented by the following general formula (1) and bisphenol-type novolak resins having structural units represented by the following general formula (2) or (3), from the viewpoint of excellent image properties and adhesiveness. A saturated or unsaturated group-containing polybasic acid anhydride is added to a resin (A′) obtained by reacting at least one selected epoxy resin (a) with a vinyl group-containing monocarboxylic acid (b). It is preferably a resin (A″) obtained by reaction.

［一般式（１）中、Ｒ^１１は水素原子又はメチル基を示し、Ｙ^１は水素原子又はグリシジル基を示し、ｎ１は１以上の整数を示す。なお、複数存在するＲ^１１及びＹ^１はそれぞれ同一でも異なっていてもよい。但し、少なくとも一つのＹ^１はグリシジル基を示す。］

[In general formula (1), R ¹¹ represents a hydrogen atom or a methyl group, Y ¹ represents a hydrogen atom or a glycidyl group, and n1 represents an integer of 1 or more. Plural R ¹¹ and Y ¹ may be the same or different. However, at least one ^Y1 represents a glycidyl group. ]

［一般式（２）中、Ｒ^１２は水素原子又はメチル基を示し、Ｙ^２はそれぞれ独立に水素原子又はグリシジル基を示す。なお、２つのＲ^１２は同一でも異なっていてもよい。但し、Ｙ^２の少なくとも一方はグリシジル基を示す。］

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

［一般式（３）中、Ｒ^１３は水素原子又はメチル基を示し、Ｙ^３はそれぞれ独立に水素原子又はグリシジル基を示す。なお、２つのＲ^１３は同一でも異なっていてもよい。但し、Ｙ^３の少なくとも一方はグリシジル基を示す。］

[In general formula (3), R ¹³ represents a hydrogen atom or a methyl group, and Y ³ each independently represents a hydrogen atom or a glycidyl group. Two R ¹³ may be the same or different. However, at least one of ^Y3 represents a glycidyl group. ]

The resin (A′) obtained by reacting the epoxy resin (a) with the vinyl group-containing monocarboxylic acid (b) is obtained by reacting the epoxy group of the epoxy resin (a) with the carboxyl of the vinyl group-containing monocarboxylic acid (b). It is presumed to have a hydroxyl group formed by an addition reaction with the group.

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

As the epoxy resin (a), a novolac-type epoxy resin represented by the general formula (1) is preferable from the viewpoint of being able to improve the solvent resistance as well as the process tolerance.

Examples of the phenol novolak type epoxy resin or cresol novolak 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 & Sumikin Chemical Co., Ltd., trade name), DEN-431, DEN-439 (manufactured by Huntsman Corporation, trade name), EOCN-120, EOCN-102S, EOCN-103S, EOCN -104S, EOCN-1012, EOCN-1025, EOCN-1027, BREN (manufactured by Nippon Kayaku Co., Ltd., trade name), EPN-1138, EPN-1235, EPN-1299 (manufactured by Huntsman Corporation, trade names), N-730, N-770, N-865, N-870, N-665, N-673, VH-4150, VH-4240 (manufactured by DIC Corporation, trade names) are commercially Available.

Further, as the epoxy resin (a), the structural unit represented by the general formula (2) and/or the general formula (3) is used from the viewpoint of further reducing the warpage of the thin film substrate and further improving the thermal shock resistance. It is preferable to use an epoxy resin having

In the above general formula (3), those in which R ¹³ is a hydrogen atom and Y ³ is a glycidyl group are EXA-7376 series (manufactured by DIC Corporation, trade name), and R ¹³ is a methyl group, Those in which ^Y3 is a glycidyl group are commercially available as EPON SU8 series (manufactured by the former Japan Epoxy Resin Co., Ltd., trade name).

Examples of the vinyl group-containing monocarboxylic acid (b) include acrylic acid, acrylic acid dimers, methacrylic acid, β-furfuryl acrylic acid, β-styryl acrylic acid, cinnamic acid, crotonic acid, α- Acrylic acid derivatives such as cyanocinnamic acid, semi-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 and a half-ester compound which is a reaction product of

A 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 singly or in combination of two or more.

Examples of hydroxyl group-containing acrylates, vinyl group-containing monoglycidyl ethers, and vinyl group-containing monoglycidyl esters used for synthesizing the above half-ester compounds, which are examples of vinyl group-containing monocarboxylic acids (b), include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate Methacrylate, dipentaerythritol pentaacrylate, pentaerythritol pentamethacrylate, glycidyl acrylate, glycidyl methacrylate.

As the dibasic acid anhydride used for synthesizing the above half-ester 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. acid, ethylhexahydrophthalic anhydride, itaconic anhydride, and the like.

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 0.6 to 0.6 to 1 equivalent of the epoxy group of the epoxy resin (a). The reaction is preferably performed at a ratio of 1.05 equivalents, more preferably 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 and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, aliphatic carbonization such as octane and decane Hydrogens, petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

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

Moreover, it is preferable to use a polymerization inhibitor for the purpose of preventing polymerization during the reaction. Polymerization inhibitors include, for example, hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol. The amount of the polymerization inhibitor used is preferably 0.01 to 1 part by mass with respect to a total of 100 parts by mass of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b). The reaction temperature is preferably 60-150°C, more preferably 80-120°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 the present invention, as the acid-modified vinyl group-containing epoxy resin (A), a resin (A″) obtained by reacting the above resin (A′) with a polybasic acid anhydride (c) is used. is also preferred.

In the resin (A″), the hydroxyl groups in the resin (A′) (including the hydroxyl groups originally present in the epoxy resin (a)) and the acid anhydride groups of the polybasic acid anhydride (c) are semi-esterified. It is presumed that

As the polybasic acid anhydride (c), those containing saturated groups and those containing unsaturated groups 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, methylhexa Examples include hydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride.

In the reaction between the resin (A') and the polybasic acid anhydride (c), 0.1 to 1.0 equivalents of the polybasic acid anhydride (c) are used with respect to 1 equivalent of hydroxyl groups 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 (A) the acid-modified vinyl group-containing epoxy resin is preferably 30 to 150 mgKOH/g, more preferably 40 to 120 mgKOH/g, even more 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 anhydride (c) is preferably 60 to 120°C.

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

In the photosensitive resin composition, the content of component (A) is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, based on the total solid content of the photosensitive resin composition. It is preferably 15 to 40% by mass, and more preferably 15 to 40% by mass. When the content of component (A) is within the above range, a coating film with excellent heat resistance, electrical properties and chemical resistance can be obtained.

[(B) a photopolymerizable monomer having an ethylenically unsaturated bond]
(B) The photopolymerizable monomer having an ethylenically unsaturated bond is preferably a compound having a molecular weight of 1000 or less, for example, hydroxyalkyls such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate. (Meth)acrylates, ethylene glycol, methoxytetraethylene glycol, glycol mono- or di(meth)acrylates such as polyethylene glycol, N,N-dimethyl (meth)acrylamide, N-methylol (meth)acrylamide (meth) ) acrylamides, aminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, tris-hydroxyethyl isocyanurate, etc. Polyhydric alcohols or polyhydric (meth)acrylates of these ethylene oxide or propylene oxide adducts, phenoxyethyl (meth)acrylate, phenolic ethylene oxide or propylene oxide adducts such as bisphenol A polyethoxydi(meth)acrylate (meth)acrylates, glycidyl ether (meth)acrylates such as glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, and melamine (meth)acrylate, acrylamide, acrylonitrile, diacetone acrylamide, styrene , vinyl toluene, and the like. These (B) photopolymerizable monomers having an ethylenically unsaturated group may be used singly or in combination of two or more. Further, it is more preferable to use a polyfunctional photopolymerizable monomer having 3 or more ethylenically unsaturated bonds in one molecule in order to increase the crosslink density by photocuring and improve heat resistance and electrical reliability. Examples of compounds having such ethylenically unsaturated bonds include trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, and EO/PO-modified trimethylol. Propane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, dipentaerythritol triacrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. mentioned.
The above "EO" means "ethylene oxide", and "PO" means "propylene oxide". "EO-modified" means having a block structure of ethylene oxide units ( _--CH.sub.2 -- _CH.sub.2 --O--), and "PO-modified" means having a block structure of propylene oxide units ( _--CH.sub.2 --CH( _CH.sub.3 ) —O—) means having a block structure.

[(C) Photoinitiator]
(C) Photopolymerization initiators include, for example, benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-methyl-1-[4-(methylthio)phenyl] -Acetophenones such as 2-morpholino-1-propanone and N,N-dimethylaminoacetophenone; Anthraquinones such as aminoanthraquinone; Thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; Benzophenone , methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis(diethylamino)benzophenone, Michler's ketone, benzophenones such as 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-di(p-methoxyphenyl) -2,4,5-triarylimidazole dimers such as 5-phenylimidazole dimer, 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer, 9-phenylacridine, acridines such as 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]ethanone 1-(O-acetyloxime), 1 -Phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl)oxime] and other oxime esters. These (C) photoinitiators can be used individually by 1 type or in combination of 2 or more types. In addition, Irgacure 819 (manufactured by BASF Japan Co., Ltd., trade name, "Irgacure" is a registered trademark), which has good curability at the bottom for photobleaching, and Irgacure 369 (BASF Japan Co., Ltd.), which does not easily generate outgassing because it is difficult to volatilize. manufactured by the company, trade name) is preferable.

Furthermore, (C) light such as tertiary amines such as N,N-dimethylaminobenzoic acid ethyl ester, N,N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine Polymerization initiation aids may be used alone or in combination of two or more.

[(D) inorganic filler]
(D) The inorganic filler will be explained. (D) Examples of inorganic fillers 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), lead lanthanum zirconate titanate (PLZT), gallium oxide ( _Ga2O3 ), spinel (MgO _{- Al2O3} ), _mullite ( _{3Al2O3-2SiO2 )} , _cordierite (2MgO- 2Al ₂ O ₃ /5SiO ₂ ), talc (3MgO.4SiO ₂ .H2O), 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 ), hydrotal Site, mica, calcined kaolin, carbon (C), etc. can be used. These (D) inorganic fillers can be used individually by 1 type or in combination of 2 or more types.

The (D) inorganic filler used in the present invention uses a silane coupling agent in order to disperse it in the resin without aggregating while maintaining the primary particle size. Commonly available silane coupling agents can be used, for example, alkylsilanes, alkoxysilanes, vinylsilanes, epoxysilanes, aminosilanes, acrylsilanes, methacrylsilanes, mercaptosilanes, sulfidesilanes, isocyanatesilanes, Sulfursilanes, styrylsilanes, alkylchlorosilanes and the like can be used. Specific compound names include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, diisopropyldimethoxysilane, isobutyltrimethoxysilane. Silane, diisobutyldimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, n-dodecylmethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane 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, vinyltri Acetoxysilane, Vinyltrimethoxysilane, Vinyltriethoxysilane, Vinyltriisopropoxysilane, Allyltrimethoxysilane, Diallyldimethylsilane, 3-Methacryloxypropyltrimethoxysilane, 3-Methacryloxypropylmethyldimethoxysilane, 3-Methacryloxysilane propyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, N-(1,3-dimethylbutylidene)-3-aminopropyltriethoxysilane, aminosilane , monomethyltriisocyanatosilane, tetraisocyanatosilane, γ-isocyanatopropyltriethoxysilane. Preferred as the silane coupling agent to be used are those of a type that reacts with the carboxyl group of the (A) acid-modified vinyl group-containing epoxy resin contained in the photosensitive resin composition, such as epoxysilane, acrylsilane, methacryl. Silanes are preferred. Since these silane coupling agents strengthen the bond between silica and resin, they increase film strength when used as a permanent mask resist, and contribute to crack resistance and the like in temperature cycle tests. Mercaptosilane and isocyanate silane may also be used. (B) Reacts with the ethylenically unsaturated group of the photopolymerizable monomer having an ethylenically unsaturated bond and is thought to exhibit the same effects as when the silane coupling agent is used.

In the photosensitive resin composition, the content of component (D) is 30 to 70% by mass based on the total solid content of the photosensitive resin composition from the viewpoint of resolution and low coefficient of thermal expansion, but 40 to 65%. % by mass is preferable, and 45 to 60% by mass is more preferable. When the content of component (D) is within the above range, the low thermal expansion coefficient, heat resistance, electrical reliability (HAST resistance), thermal shock resistance, resolution, film strength, etc. can be further improved. . If the filling amount exceeds 70% by mass, it becomes difficult to disperse it in the resin, and the flowability of the photosensitive resin composition tends to decrease. If the filling amount is less than 30% by mass, it tends to be difficult to obtain crack resistance during reflow mounting.

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

Among (D) inorganic fillers, silica fine particles are preferably used from the viewpoint of improving low expansion coefficient and heat resistance. In addition, from the viewpoint of improving the adhesive strength between the underfill material and the cured film after solder heat resistance, HAST properties (electrical reliability), crack resistance (thermal shock resistance), and PCT resistance test (pressure cooker test), It is also preferred to use barium sulfate fine particles. From the viewpoint of improving the anti-aggregation effect, the silica fine particles are preferably surface-treated with alumina and/or an organic silane compound.

When silica is used, the content is preferably 30 to 60% by mass, more preferably 35 to 55% by mass, based on the total solid content of the photosensitive resin composition. When the content of the silica fine particles is within the above range, it is possible to further improve the low expansion coefficient, solder heat resistance, and adhesive strength between the underfill material and the cured film after the PCT resistance test.

The photosensitive resin composition of the present invention may further contain (E) a pigment, (F) a curing agent, and/or (G) an elastomer, in addition to the components (A) to (D) described above. Furthermore, (H) an epoxy resin curing agent may be included. Each component will be described below.

[(E) Pigment]
The photosensitive resin composition preferably contains a pigment as component (E). (E) Pigments are preferably used in accordance with a desired color to improve the distinguishability and appearance of manufacturing equipment, or when concealing wiring patterns. (E) The pigment is used as needed according to the desired color, and a coloring agent that develops the desired color may be appropriately selected and used. Known colorants such as green, iodine green, diazo yellow and crystal violet are preferred.
The content of the pigment (E) is preferably 0.1 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, based on 100 parts by mass of the total solid content in the photosensitive resin composition. (E) A wiring pattern can be concealed as content of a component is in the said range.

[(F) Curing agent]
As the curing agent (F), a compound that itself cures with heat, ultraviolet rays, etc., or a compound that cures by reacting with the carboxyl group or hydroxyl group of the acid-modified vinyl group-containing epoxy resin (A) with heat, ultraviolet rays, etc. is preferable. . By using the curing agent (F), the heat resistance, adhesiveness, chemical resistance, etc. of the cured film formed from the photosensitive resin composition can be improved.

(F) Curing agents include, for example, thermosetting compounds such as epoxy compounds, melamine compounds, urea compounds, oxazoline compounds, and blocked isocyanates. Examples of epoxy compounds include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, novolac type epoxy resin, bisphenol S type epoxy resin, and biphenyl type 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.
Melamine compounds include, for example, triaminotriazine, hexamethoxymelamine, and hexabutoxylated melamine.
Urea compounds include, for example, dimethylol urea.

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(isocyanatomethyl)cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, and the like. and polyisocyanate compounds, and adducts, biurets and isocyanurates thereof.

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-parellolactam, γ-butyrolactam and β-propiolactam; Active methylene-based 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; mercaptan blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol and ethylthiophenol; acid amide blocking agents such as acetic amide and benzamide; imides such as succinimide and maleic imide system blocking agents; amine blocking agents such as xylidine, aniline, butylamine and dibutylamine; imidazole blocking agents such as imidazole and 2-ethylimidazole; and imine blocking agents such as methyleneimine and propyleneimine.

(F) The curing agent preferably contains an epoxy compound (epoxy resin) and/or blocked isocyanate from the viewpoint of being able to further improve the heat resistance of the cured film. Combined use is more preferable.

(F) A hardening agent is used individually by 1 type or in combination of 2 or more types. (F) When using a curing agent, the content is preferably 2 to 40% by mass, more preferably 3 to 30% by mass, based on the total solid content of the photosensitive resin composition. More preferably 5 to 20% by mass. By setting the content of the curing agent (F) within the range of 2 to 40% by mass, it is possible to further improve the heat resistance of the formed cured film while maintaining good developability.

[(G) Elastomer]
(G) Elastomer can be suitably used when the photosensitive resin composition of the present invention is used for a semiconductor package substrate. By adding (G) an elastomer to the photosensitive resin composition of the present invention, a crosslinking reaction (curing reaction) proceeds by ultraviolet light or heat, and (A) an acid-modified vinyl group-containing epoxy resin shrinks upon curing. , it is possible to solve the problem that distortion (internal stress) is applied to the inside of the resin and the flexibility and adhesiveness are lowered.

(G) Elastomers include, for example, 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 consist 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.

Styrenic elastomers include styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-ethylene-butylene-styrene block copolymers, styrene-ethylene-propylene-styrene block copolymers, 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, Tufprene, Solprene T, Asaprene T, Tuftec (manufactured by Asahi Kasei Corporation), Elastomer AR (manufactured by Aron Kasei Co., Ltd.), Kraton G, Califlex (manufactured by Kraton Polymer Japan Co., Ltd.), JSR-TR, TSR-SIS, Dynaron (manufactured by JSR Corporation), Denka STR (manufactured by Denka Corporation), Quintac (manufactured by Nippon Zeon Co., Ltd.), TPE-SB series (manufactured by Sumitomo Chemical Co., Ltd.), Lavalon (manufactured by Mitsubishi Chemical Corporation), Septon, Hybler (manufactured by Kuraray Co., Ltd.), Sumiflex (manufactured by Sumitomo Bakelite Co., Ltd.), Rheostomer, Actimer (manufactured by Riken Technos Co., Ltd.), and the like can be used.

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

A urethane-based elastomer is composed of structural units of a hard segment composed of a low-molecular-weight glycol and diisocyanate and a soft segment composed of a high-molecular-weight (long-chain) diol and diisocyanate.

As low-molecular-weight glycols, 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 48-500.

Examples of high-molecular (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), poly(1,6-hexylene-neopentylene adipate). The number average molecular weight of the high molecular weight (long chain) diol is preferably 500 to 10,000.

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

Polyester-based elastomers include those obtained by polycondensation of 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. 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 are included. These compounds can be used individually by 1 type or in combination of 2 or more types.
Specific examples of diol compounds include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, and 1,4-cyclohexanediol. and alicyclic diols, or dihydric phenols represented by the following general formula (4).

［一般式（４）中、Ｙ^１１は炭素数１～１０のアルキレン基、炭素数４～８のシクロアルキレン基、－Ｏ－、－Ｓ－、又は、－ＳＯ_２－を示し、Ｒ^２１及びＲ^２２はハロゲン原子又は炭素数１～１２のアルキル基を示し、ｐ及びｑは０～４の整数を示し、ｒは０又は１を示す。］

[In 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 represents a halogen atom or an alkyl group having 1 to 12 carbon atoms; p and q represent integers of 0 to 4; r represents 0 or 1; ]

Specific examples of the dihydric phenol represented by general formula (4) include bisphenol A, bis-(4-hydroxyphenyl)methane, bis-(4-hydroxy-3-methylphenyl)propane and resorcinol. These compounds can be used individually by 1 type or in combination of 2 or more types.

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

Polyamide-based elastomers are broadly classified into two types: a polyether block amide type and a polyether ester block amide type using polyamide as the hard segment and polyether or polyester as the soft segment.

Polyamide-6, 11, 12 and the like are used as the polyamide. As the polyether, polyoxyethylene, polyoxypropylene, polytetramethylene glycol and the like are used. Specifically, UBE polyamide elastomer (manufactured by Ube Industries, Ltd.), Daiamide (manufactured by Daicel-Evonik Co., Ltd.), PEBAX (manufactured by Toray Industries, Inc.), Grillon ELY (manufactured by Em Chemie Japan Co., Ltd.), Nopamid (Mitsubishi Chemical Corporation company) and Grelix (manufactured by DIC Corporation) can be used.

The acrylic elastomer has acrylic acid ester as a main component, and ethyl acrylate, butyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, and the like are used. Moreover, glycidyl methacrylate, allyl glycidyl ether, etc. are used as a cross-linking monomer. 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, and the like can be used.

Silicone-based elastomers are mainly composed of organopolysiloxane, and are classified into polydimethylsiloxane-based, polymethylphenylsiloxane-based, and polydiphenylsiloxane-based elastomers. Some are partially modified with a vinyl group, an alkoxy group, or the like. Specific examples include KE series (manufactured by Shin-Etsu Chemical Co., Ltd.), SE series, CY series, and SH series (manufactured by Toray Dow Corning Silicone Co., Ltd.).

In addition to the elastomers described above, rubber-modified epoxy resins can also be used. Rubber-modified epoxy resins include, for example, 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 can be obtained by modification with acid-modified butadiene-acrylonitrile rubber, terminal amino-modified silicone rubber, or the like. Among these elastomers, in terms of shear adhesiveness, butadiene-acrylonitrile copolymer modified at both ends with carboxyl groups, Espel (manufactured by Hitachi Chemical Co., Ltd., Espel 1612, 1620), which is a polyester elastomer having a hydroxyl group, epoxidized Polybutadiene and the like are preferred. Elastomers that are liquid at room temperature (25° C.) are particularly preferred.

(G) When an elastomer is used, 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. More preferably, it is up to 10% by mass. (G) By setting the content of the elastomer within the range of 1 to 20% by mass, it is possible to further improve the thermal shock resistance and the adhesive strength between the underfill material and the cured film while maintaining good developability. can. Moreover, when used for a thin film substrate, the warpage of the thin film substrate can be reduced.

[(H) epoxy resin curing agent]
To the photosensitive resin composition of the present invention, (H) an epoxy resin curing agent can be added 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 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-xylylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, polybasic hydrazides organic acid salts and/or epoxy adducts thereof; amine complexes of boron trifluoride; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xylyl - triazine derivatives such as S-triazine; trimethylamine, triethanolamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa(N-methyl)melamine, 2,4,6 - tertiary amines such as tris (dimethylaminophenol), tetramethylguanidine, m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolak, alkylphenol novolak; tributylphosphine, triphenylphosphine, tris- Organic phosphines such as 2-cyanoethylphosphine; Phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl)phosphonium bromide and hexadecyltributylphosnium chloride; Quaternary compounds such as benzyltrimethylammonium chloride and phenyltributylammonium chloride ammonium salts; the above polybasic acid anhydrides; diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrylium hexafluorophosphate and the like. These (H) epoxy resin curing agents are used singly or in combination of two or more.

(H) When an epoxy resin curing agent is used, its content 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. It is more preferable to have

[(I) thermoplastic resin]
In addition, (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) Thermoplastic resins include, for example, acrylic resins and urethane resins. (I) The content when the thermoplastic resin is contained 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. .

Further, 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 phosphorus compounds, aromatic condensed phosphates, and halogen-containing condensed phosphates can also be added.

As a 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 and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, aliphatic carbonization such as octane and decane Hydrogens, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, solvent naphtha, and other petroleum solvents. A diluent is used individually by 1 type or in combination of 2 or more types. When a diluent is used, the content can be appropriately adjusted from the viewpoint of the applicability 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 components with a roll mill, bead mill, or the like.

The photosensitive resin composition of the present invention has properties and reliability required for printed wiring boards such as rigid wiring boards and flexible wiring boards, solder resists and interlayer insulating films provided for package substrates, surface protective films for semiconductors, and the like. can satisfy you. In addition, the solder resist obtained from the photosensitive resin composition of the present invention is sufficiently excellent in thermal shock resistance. , mechanical properties such as elongation and tensile strength, and HAST resistance.

[Photosensitive film]
Preferred embodiments of the photosensitive film of the present invention are described below. The photosensitive film comprises a support layer, a photosensitive layer containing the photosensitive resin composition formed on the support layer, and a protective film layer laminated on the photosensitive layer.

The photosensitive layer is formed by dissolving the above-described photosensitive resin composition in a solvent (diluent) as described above if necessary to obtain a solution having a solid content of about 30 to 70% by mass, and then applying this solution on the support layer. It is preferable to form by coating and drying. The coating can be performed by a known method using, for example, a roll coater, comma coater, gravure coater, air knife coater, die coater, bar coater, or the like. Although the thickness of the photosensitive layer varies depending on the application, it is preferably 5 to 100 μm, more preferably 10 to 60 μm, as the thickness after drying after removing the diluent by heating and/or blowing hot air. If the thickness is less than 5 μm, industrial coating tends to be difficult, and if it exceeds 100 μm, the sensitivity and resolution of the photosensitive resin composition layer tend to decrease.

Examples of the support layer included in the photosensitive film include heat-resistant and solvent-resistant polymer films such as polyester such as polyethylene terephthalate, polypropylene, and polyethylene.

The thickness of the support layer is preferably 5 to 100 μm, more preferably 10 to 30 μm. If the thickness is less than 5 µm, the support tends to be easily torn when the support is peeled off from the photosensitive film before development. In the present embodiment, the polyester resin as described above is used to form the photosensitive layer. can also maintain its flexibility and resolution.

Protective film layers include polyethylene film, polypropylene film, polyethylene terephthalate film, surface-treated paper, and the like. It is preferable that the protective film layer has a lower adhesive strength between the photosensitive layer and the protective film layer than the adhesive strength between the photosensitive layer and the support layer.

The photosensitive film composed of the three layers of the support layer, the photosensitive layer and the protective film layer as described above may be stored as it is, or may be rolled on a winding core with a protective film layer interposed. It can be rolled up and stored.

[Method for forming resist pattern, printed wiring board]
The method for forming a resist pattern of the present invention uses a photosensitive resin composition on an insulating substrate of a laminated substrate comprising an insulating substrate and a conductor layer having a circuit pattern formed on the insulating substrate so as to cover the conductor layer. The method is characterized in that a photosensitive layer is laminated on the substrate, a predetermined portion of the photosensitive layer is irradiated with an actinic ray to form an exposed portion, and then portions of the photosensitive layer other than the exposed portion are removed.

In the embodiment, the photosensitive layer of the photosensitive film is used as the photosensitive layer using the photosensitive resin composition. A photosensitive layer made of the above photosensitive resin composition is formed on a substrate on which a resist is to be formed. The protective film of the photosensitive film is peeled off from the photosensitive resin composition layer, and the exposed surface is adhered by lamination or the like. A method of laminating under reduced pressure is also preferable from the viewpoint of improving adhesion and followability. The photosensitive resin composition can also be applied onto the substrate by a known method such as a method of applying a varnish of the photosensitive resin composition by a screen printing method or a roll coater. Next, an exposure step is performed in which a predetermined portion of the photosensitive resin composition layer is irradiated with actinic rays through a mask pattern to photo-cure the irradiated portion of the photosensitive resin composition layer.

As the light source for the actinic rays, known light sources such as carbon arc lamps, mercury vapor arc lamps, ultra-high pressure mercury lamps, high pressure mercury lamps, and xenon lamps that effectively emit ultraviolet rays are used. In addition, photographic flood light bulbs, solar lamps, and the like, which effectively emit visible light and ultraviolet light, are also used.

Furthermore, when a support is present on the photosensitive layer, after removing the support, wet development or dry development is performed to remove a portion that has not been photocured (unexposed portion), A resist pattern can be formed. In the case of wet development, safe and stable developer having good operability is used, for example, alkaline aqueous solution such as sodium hydroxide, aqueous developer, organic solvent and the like. Methods of development include a dip method, a battle method, a spray method, a high-pressure spray method, brushing, slapping, and the like.

After completion of the development step, it is preferable to perform ultraviolet irradiation or heating using a high-pressure mercury lamp for the purpose of improving solder heat resistance, chemical resistance, and the like. In the case of irradiating with ultraviolet rays, the irradiation dose can be adjusted as necessary, for example, the irradiation can be performed at a dose of about 0.05 to 10 J/cm ² . When heating the resist pattern, it is preferable to heat the resist pattern at a temperature of about 130 to 200° C. for about 15 to 90 minutes.

Both ultraviolet irradiation and heating may be performed. In this case, both may be performed at the same time, or one of them may be performed before the other. When ultraviolet irradiation and heating are performed at the same time, heating to 60 to 150° C. is preferable from the viewpoint of imparting better solder heat resistance and chemical resistance.

The permanent resist thus formed also serves as a protective film for the wiring after it is soldered to the board, and has the various characteristics of a solder resist. It can be used as a solder resist. The solder resist is used, for example, as a plating resist or an etching resist when the substrate is plated or etched, and is left on the substrate as it is and is used as a protective film for protecting wiring and the like.

After that, the substrate provided with the permanent resist is mounted with semiconductor elements (for example, wire bonding, solder connection), and then attached to an electronic device such as a personal computer.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

For example, another embodiment of the photosensitive film of the present invention may comprise only a photosensitive layer and a support layer without a protective film layer. Further, the printed wiring board of the present invention may be a multilayer printed wiring board in which a plurality of conductive layers and insulating layers are alternately laminated on the insulating substrate or on both sides of the insulating substrate. In that case, the photosensitive resin composition of the present invention The cured product functions as an interlayer insulating film for reliably insulating between conductive layers.

Moreover, in the manufacturing method of a printed wiring board, you may use the photosensitive resin composition of this invention. For example, a printed wiring board manufacturing method comprising an insulating substrate, a conductor layer having a circuit pattern formed on the insulating substrate, and a permanent resist layer formed to cover the conductor layer, A photosensitive layer is laminated on an insulating substrate using the photosensitive resin composition of the present invention so as to cover the conductor layer, and a predetermined portion of the photosensitive layer is irradiated with actinic rays to form an exposed portion. , a method for manufacturing a printed wiring board, in which portions other than the exposed portion are removed, and the like.

EXAMPLES The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples.

[Synthesis Example: Production of Acid-Modified Vinyl Group-Containing Epoxy Resins (A-1, 2, 3, 4)]
350 parts by mass of a bisphenol F novolac type epoxy resin (EXA-7376, manufactured by DIC Corporation) having a structural unit (R ¹³ =hydrogen atom, Y ³ =glycidyl group) represented by general formula (3), 70 parts by mass of acrylic acid 0.5 parts by mass of methyl hydroquinone, 120 parts by mass of carbitol acetate, and a catalyst (triphenylphosphine) were charged, heated to 90° C. and stirred to cause a reaction, and the mixture was completely dissolved. Next, the obtained solution was cooled to 60° C., 2 parts by mass of triphenylphosphine was added, heated to 100° C., and reacted until the acid value of the solution reached 1 mgKOH/g. 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 give a solid concentration of 73 mass. % THPAC-modified bisphenol F-type novolac epoxy acrylate (hereinafter referred to as “acid-modified vinyl group-containing epoxy resin (A-1, 2, 3, 4) (dispersion degree; A-1 = 6.0 , A-2 = 4.5, A-3 = 3.5, A-4 = 2.5)), where the amount of catalyst (0 to 2 parts by mass), the heating temperature (80 ~120°C), resins with different degrees of dispersion were obtained by changing the time.

(Measurement of degree of dispersion)
The number average molecular weight (Mn), weight average molecular weight (Mw) and Mw/Mn (dispersity) of THPAC-modified bisphenol F-type novolac epoxy acrylate were determined by GPC (gel permeation chromatography), and converted from the elution time of standard polystyrene at 25°C. As the measurement device, EcoSEC, HLC-8320GPC manufactured by Tosoh Corporation is used, tetrahydrofuran is used as the eluent for GPC, and the columns are Gelpack GL-A-150 and Gelpack GL-A-10 ( (trade name) manufactured by Hitachi High-Technologies Corporation) was used.

(Examples 1-3, Comparative Examples 1-4)
Each material shown in Table 1 below was blended in the amount shown in the same table (unit: parts by mass), kneaded with a three-roll mill, and carbitol acetate was added so that the solid content concentration was 70% by mass. , to obtain a photosensitive resin composition. The compounding amount of each material in Table 1 below indicates the compounding amount of the solid content.

The details of each material in Table 1 are as follows.
[(A) Acid-modified vinyl group-containing epoxy resin]
* 1 (acid-modified vinyl group-containing epoxy resin (A-1)): THPAC-modified bisphenol F-type novolak epoxy acrylate prepared in Synthesis Example (dispersion degree Mw/Mn = 6.0)
*2 (acid-modified vinyl group-containing epoxy resin (A-2)): THPAC-modified bisphenol F-type novolac epoxy acrylate prepared in Synthesis Example (dispersion degree Mw/Mn = 4.5)
*3 (Acid-modified vinyl group-containing epoxy resin (A-3)): THPAC-modified bisphenol F-type novolac epoxy acrylate prepared in Synthesis Example (dispersion degree Mw/Mn = 3.5)
* 4 (acid-modified vinyl group-containing epoxy resin (A-4)): THPAC-modified bisphenol F-type novolac epoxy acrylate prepared in Synthesis Example (dispersion degree Mw/Mn = 2.5)
[(B) a photopolymerizable monomer having an ethylenically unsaturated bond]
* 5 (Aronix M402): Dipentaerythritol hexaacrylate (manufactured by Toagosei Co., Ltd.)
[(C) Photoinitiator)]
* 6 (Irgacure 907): (2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, manufactured by BASF Japan Ltd.)
[(D) inorganic filler]
* 7 (SFP-20M): Silica fine particles (ultrafine spherical silica, average particle size 0.3 μm, manufactured by Denka Co., Ltd.)
* 8 (B-34): barium sulfate fine particles (average particle size 0.3 μm, manufactured by Sakai Chemical Industry Co., Ltd.)
[(F) Curing agent]
* 9 (YSLV-80XY): Epoxy resin (tetramethylbisphenol F type, epoxy equivalent = 192 g / eq, melting point = 72 ° C., manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
* 10 (RE-306): Epoxy resin (phenol novolak type epoxy resin, manufactured by Nippon Kayaku Co., Ltd.)
[(G) Elastomer]
* 11 (PB-3600): Epoxidized polybutadiene (manufactured by Daicel Co., Ltd.)

[Silica residue]
The photosensitive resin compositions of Examples and Comparative Examples were coated on a copper-clad laminate (MCL-E-67, glass cloth-based epoxy resin substrate, manufactured by Hitachi Chemical Co., Ltd.) so that the film thickness after drying was 15 μm. , and then dried at 75°C for 30 minutes using a hot air circulating dryer. The resulting coating film was irradiated with ultraviolet light at an integrated exposure of 100 mJ/ ^cm2 through a negative film in which non-light-transmitting portions with a diameter of 80 µm were scattered in a 1 × 1 cm square area, and a 1% by weight sodium carbonate aqueous solution was applied. was spray-developed at a pressure of 1.8 kgf/cm ² for 60 seconds, and the unexposed area was dissolved and developed to form an image. After that, the aperture was observed at 10,000 magnifications using an SEM (model number: S4200, field emission scanning electron microscope manufactured by High Technologies Co., Ltd.), and the residual silica residue was evaluated according to the following criteria. Table 2 shows the evaluation results.
A: 1 or less silica residue in 1 field of view B: 2 or more, less than 10 silica residues in 1 field of view C: 10 or more silica residues in 1 field of view

[HAST resistance evaluation]
The copper surface of a printed wiring board substrate (MCL-E-679, glass cloth substrate high Tg epoxy resin substrate, manufactured by Hitachi Chemical Co., Ltd., trade name) in which a 12 μm thick copper foil is laminated on a glass epoxy substrate is etched. to form a comb-shaped electrode with a line/space of 28 μm/32 μm. Using this substrate as an evaluation substrate, a cured resist was formed on the substrate as described above, and then exposed to conditions of 135° C., 85% RH and DC 5 V for 200 hours. After that, the degree of occurrence of migration was observed with a 100x metallographic microscope and evaluated according to the following criteria.
That is, "3" indicates that migration did not occur in the permanent resist film and the resistance value did not decrease. , and those in which the resistance value also decreased were evaluated as "1".
Table 2 shows the evaluation results.

[Thermal expansion coefficient/glass transition point (Tg) evaluation]
The photosensitive resin composition solution was uniformly applied onto a 16 μm-thick polyethylene terephthalate film (G2-16, manufactured by Teijin Limited, trade name) as a support layer so that the film thickness after drying was 30 μm. was dried using a hot air convection dryer at 75°C for about 30 minutes. Subsequently, on the surface of the photosensitive resin composition layer opposite to the side in contact with the support, a polyethylene film (NF-15, manufactured by Tamapoly Co., Ltd., trade name) is laminated as a protective film to obtain a photosensitive resin composition layer. got the film. The entire surface of the photosensitive film was exposed to light, and then allowed to stand at room temperature (25°C) for 1 hour. After the spray development, the film was irradiated with ultraviolet rays at 2 J/cm 2 using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd., and further heat-treated at 170° C. for 60 minutes. Next, after cutting into a width of 3 mm and a length of 30 mm with a cutter knife, the polyethylene terephthalate film as a support on the laminate was peeled off to obtain a cured photosensitive resin (test piece) for thermal expansion coefficient evaluation. . Using a TMA device (thermo-mechanical analyzer) SS6000 (manufactured by Seiko Instruments Inc.), the thermal expansion coefficient (10 ⁻⁶ /° C., ppm) in tensile mode was measured. The tensile load is 5 g, the span (distance between chucks) is 15 mm, and the heating rate is 10° C./min. First, the test piece was attached to the apparatus, heated from room temperature (25° C.) to 160° C., and left for 15 minutes. After that, it was cooled to −60° C. and measured from −60° C. to 250° C. at a heating rate of 10° C./min to measure the glass transition point and thermal expansion coefficient. Table 2 shows the evaluation results.

As is clear from Table 2, Examples 1 to 3 are excellent in general properties such as silica residue, electrical reliability (HAST resistance), low coefficient of thermal expansion and high Tg. It is also found that the acid-modified vinyl group-containing epoxy resin having a degree of dispersion of 3.5 or less has a particularly small amount of silica residue and is excellent in coefficient of thermal expansion and heat resistance. On the other hand, as is clear from Table 2, Comparative Examples 1 to 4 are found to have insufficient silica residue and insufficient electrical reliability. Therefore, according to the photosensitive resin composition of the present invention, a permanent mask resist having a low coefficient of thermal expansion, excellent HAST resistance, and a high Tg can be obtained while maintaining a low silica residue.

Claims (6)

A photosensitive resin composition containing (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable monomer having an ethylenically unsaturated bond, (C) a photopolymerization initiator, and (D) an inorganic filler and the acid-modified vinyl group-containing epoxy resin of component (A) is an epoxy resin (a), which is a novolac epoxy resin represented by the following general formula (1), and a vinyl group-containing monocarboxylic acid (b). A resin (A'') obtained by reacting a saturated or unsaturated group-containing polybasic acid anhydride with a resin (A') obtained by reacting (however, Mw/Mn (weight average molecular weight/number average molecular weight ) and a resin obtained by reacting an o-cresol novolac resin with acrylic acid and then with tetrahydrophthalic anhydride, and o-cresol. ), and (A) an acid A photosensitive resin composition in which the content of the modified vinyl group-containing epoxy resin is 15 to 60% by mass relative to the total solid content, and (D) the content of the inorganic filler is 30 to 70% by mass relative to the total solid content. thing.

[In general formula (1), R ¹¹ represents a hydrogen atom or a methyl group, Y ¹ represents a hydrogen atom or a glycidyl group, and n1 represents an integer of 1 or more. Plural R ¹¹ and Y ¹ may be the same or different. However, at least one ^Y1 represents a glycidyl group . ] 2. The photosensitive resin composition according to claim 1, wherein (B) a photopolymerizable monomer having an ethylenically unsaturated bond is a polyfunctional photopolymerizable monomer having three or more ethylenically unsaturated bonds in one molecule. 3. The photosensitive resin composition according to claim 1, further comprising (E) a pigment. A photosensitive film comprising a support and a photosensitive layer formed from the photosensitive resin composition according to any one of claims 1 to 3. 4. The photosensitive material according to any one of claims 1 to 3, on the insulating substrate of a laminated substrate comprising an insulating substrate and a conductive layer having a circuit pattern formed on the insulating substrate, so as to cover the conductive layer. A photosensitive layer is laminated using a flexible resin composition, a predetermined portion of the photosensitive layer is irradiated with an actinic ray to form an exposed portion, and then portions of the photosensitive layer other than the exposed portion are removed. and a method of forming a resist pattern. An insulating substrate, a conductor layer having a circuit pattern formed on the insulating substrate, and the photosensitive resin composition according to any one of claims 1 to 3 so as to cover the conductor layer. and a permanent resist layer.