JP7035304B2 - A photosensitive resin composition, a photosensitive film using the photosensitive resin composition, a method for forming a resist pattern, and a printed wiring board. - Google Patents

Description

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

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

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

For example, in a flexible wiring board using mounting methods such as FC, TAB, and COF, a thermosetting resin paste is screen-printed except for a rigid wiring board, an IC chip, an electronic component, or an LCD panel and a connection wiring pattern portion. It is thermoset to form a permanent mask resist (see, for example, Patent Document 1).

Further, in recent years, with the increase in the density of wiring patterns, high resolution is required for permanent mask resists, and photosensitive resin compositions for forming patterns by a photographic method have been actively used. Among them, alkaline-developed type that can be developed with a weak alkaline aqueous solution such as an aqueous sodium carbonate solution has become the mainstream from the viewpoint of work environment conservation and global environment conservation. In addition, with the trend toward miniaturization and higher performance of electronic devices, there is a remarkable tendency for higher densities due to narrower pitches in the wiring of semiconductor chips. The flip-chip connection method for joining is the mainstream. This flip-chip connection method is a semiconductor mounting method by a reflow method in which solder balls are arranged between a substrate and a semiconductor chip and the whole is heated and melt-bonded. Therefore, the board itself is exposed to a high temperature environment during solder reflow, and the thermal shrinkage of the board causes a large stress on the solder balls that connect the board and the semiconductor, resulting in poor wiring connection and cracks in the permanent mask resist and underfill. ) May occur. Therefore, a material having a low thermal expansion rate is required as an insulating material used for a printed wiring board.

With the higher definition of the wiring pattern and insulation pattern (permanent mask resist) in the printed wiring board, the spacing pitch between the wirings has become finer, so the excellent electrical reliability between the wirings (particularly, the electrical reliability after moisture absorption). (HAST (High Accelerated Stress Test) resistance)) is required.
In the production thereof, an electroless plating method that does not require a lead wire has been adopted (for example, Patent Document 2). The electroless plating method has features such as a uniform plating film thickness and high smoothness. However, since the pH of the plating solution is high and it is strongly alkaline, and the liquid temperature is set to a high temperature of about 90 ° C. in order to improve the plating precipitation rate, the damage to the permanent mask resist tends to be large. Therefore, the permanent mask resist is required to have further improvement in electroless plating resistance, which is resistant to damage caused by the plating solution used for electroless plating.

In addition, due to the decrease in the thermal expansion rate, increasing the amount of the inorganic filler tends to cause a phenomenon in which the filler remains after alkaline development. When this filler residue is generated, the electrical connection becomes insufficient and the electrical reliability deteriorates. Therefore, improvement of the filler residue is required.

Japanese Patent Application Laid-Open No. 2003-198105 Japanese Unexamined Patent Publication No. 2006-190848

The present invention has a photosensitive resin composition having excellent heat resistance and a low thermal expansion rate, and further achieving good resolution, electrical reliability (HAST resistance), and 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.

As a result of repeated studies on the solder resist characteristics and composition that can satisfy these high heat resistance and low thermal expansion rate, good electric reliability (HAST resistance), good filler developability, and elimination of filler residue, the inventors (A). A photosensitive resin composition containing (B) 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 as a component is a specific high heat-resistant compound, and a resin with a dispersibility of 2.0 to 5.0 represented by Mw / Mn is applied, and an inorganic filler is added by 30 to 70 mass. It was found that the content of% can achieve both heat resistance, electric reliability, and filler developability (elimination of filler residue) without deteriorating the linear thermal expansion rate.

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). ) A photosensitive resin composition containing an inorganic filler, wherein the acid-modified vinyl group-containing epoxy resin of the component (A) is a compound represented by the general formula (1) or the general formula (2) (however, Mw / Mn (weight average molecular weight / number average molecular weight) with a dispersibility of 2.0 to 5.0) is included, and (D) the content of the inorganic filler is 30 to 70 mass with respect to the total solid content. It is characterized by being%.

［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 the general formula (1), R ¹¹ represents a hydrogen atom or a methyl group, Y ¹ represents a hydrogen atom or a glycidyl group, and n 1 represents an integer of 1 or more. The plurality of R ¹¹ and Y ¹ may be the same or different from each other. However, at least one Y ¹ represents a glycidyl group. In the general formula (2), R ¹² represents a hydrogen atom or a methyl group, and Y ² independently represents a hydrogen atom or a glycidyl group. The two R ^12s may be the same or different. However, at least one of Y ² shows a glycidyl group. ]

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

Further, the photosensitive film of the present invention includes a [4] support and a photosensitive layer formed from the photosensitive resin composition according to any one of the above [1] to [3].
Further, the method for forming a resist pattern of the present invention is described above so as to cover the conductor layer on the insulating substrate of a laminated substrate including an insulating substrate and a conductor layer having a circuit pattern formed on the insulating substrate. The 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 active light to form an exposed portion, and then the above-mentioned It is characterized in that a portion of the photosensitive layer other than the exposed portion is removed.
Further, the printed wiring board of the present invention has 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. The present invention comprises a permanent resist layer formed by using the photosensitive resin composition according to the above.

According to the present invention, a photosensitive resin composition for a protective film for a printed wiring board, which can achieve both high heat resistance, resolution, electrical reliability (HAST resistance), and filler developability without deteriorating the linear thermal expansion rate. It is possible to provide a photosensitive film using this, a method for forming a resist pattern, and a printed wiring board.

In the present invention, the (meth) acrylic acid indicates acrylic acid or methacrylic acid, the (meth) acrylate means acrylate or the corresponding methacrylate, and the (meth) acryloyl group means an acryloyl group or a methacrylic acid group. ..
Hereinafter, preferred embodiments of the present invention will be described in detail.
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 used in the present invention (having a dispersity of 2.0 to 5.0 represented by Mw / Mn) will be described.
The (A) acid-modified vinyl group-containing epoxy resin used in the present invention has a dispersibility of 2.0 to 5.0 represented by Mw / Mn, is capable of alkaline development, and is a solution. A group consisting of a novolak type epoxy resin represented by the following general formula (1) and a bisphenol type novolak resin having a structural unit represented by the following general formula (2) or (3) from the viewpoint of excellent image quality and adhesiveness. A saturated or unsaturated group-containing polybasic acid anhydride is added to the resin (A') obtained by reacting at least one epoxy resin (a) selected from the above with a vinyl group-containing monocarboxylic acid (b). It is preferably the resin (A ") obtained by the 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 the general formula (1), R ¹¹ represents a hydrogen atom or a methyl group, Y ¹ represents a hydrogen atom or a glycidyl group, and n 1 represents an integer of 1 or more. The plurality of R ¹¹ and Y ¹ may be the same or different from each other. However, at least one Y ¹ 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 the general formula (2), R ¹² represents a hydrogen atom or a methyl group, and Y ² independently represents a hydrogen atom or a glycidyl group. The two R ^12s may be the same or different. However, at least one of Y ² shows 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 the general formula (3), R ¹³ represents a hydrogen atom or a methyl group, and Y ³ independently represents a hydrogen atom or a glycidyl group. The two R ^13s may be the same or different. However, at ^least one of Y3 shows a glycidyl group. ]

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

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

As the epoxy resin (a), the novolak type epoxy resin represented by the general formula (1) is preferable from the viewpoint of excellent process margin and improvement of solvent resistance.

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

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

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

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, cinnamon acid, crotonic acid, and α-. Acrylic acid derivatives such as cyanocinnamic acid, semi-ester compounds which 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 thereof include semi-ester compounds which are reaction products of.

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

Examples of the hydroxyl group-containing acrylate, vinyl group-containing monoglycidyl ether, and vinyl group-containing monoglycidyl ester used for synthesizing the semiester compound which is an example of the vinyl group-containing monocarboxylic acid (b) include hydroxyethyl acrylate and hydroxyethyl. Methacrylate, Hydroxypropyl Acrylate, Hydroxypropyl Methacrylate, Hydroxybutyl Acrylate, Hydroxybutyl Methacrylate, Polyethylene Glycol Monoacrylate, Polyethylene Glycol Monomethacrylate, Trimethylol Propane Diacrylate, Trimethylol Propane Dimethacrylate, Pentaerythritol Triacrylate, Pentaerythritol Tri Examples thereof include methacrylate, dipentaerythritol pentaacrylate, pentaerythritol pentamethacrylate, glycidyl acrylate, and glycidyl methacrylate.

As the dibasic acid anhydride used for the synthesis of the semi-ester compound, one containing a saturated group and one containing an unsaturated group can be used. Specific examples of the dibasic acid anhydride include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Examples thereof include acid, ethylhexahydrophthalic anhydride, phthalic 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). It is preferable to react at a ratio of 1.05 equivalent, and more preferably to react at a ratio of 0.8 to 1.0 equivalent.

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

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 and the like can be used. The amount of the catalyst used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass in total of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b).

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

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

Further, in the present invention, as the (A) acid-modified vinyl group-containing epoxy resin, the resin (A ") obtained by reacting the above-mentioned resin (A') with the polybasic acid anhydride (c) is used. Is also preferable.

In the resin (A "), the hydroxyl group in the resin (A') (including the original hydroxyl group in the epoxy resin (a)) and the acid anhydride group of the polybasic acid anhydride (c) are semi-esterified. It is presumed that it has been done.

As the polybasic acid anhydride (c), one containing a saturated group and 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, and methylhexa. Examples thereof 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 equivalent of the polybasic acid anhydride (c) is used with respect to 1 equivalent of the hydroxyl group in the resin (A'). By reacting, the acid value of the acid-modified vinyl group-containing epoxy resin can be adjusted.

The acid value of the (A) acid-modified vinyl group-containing epoxy resin is preferably 30 to 150 mgKOH / g, more preferably 40 to 120 mgKOH / g, and 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 characteristics 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. Further, as the (A) acid-modified vinyl group-containing epoxy resin, a styrene-maleic acid-based product such as a hydroxyethyl acrylate-modified product of a styrene-maleic anhydride copolymer or a hydroxyethyl acrylate-modified product of a styrene-maleic anhydride copolymer is used. A part of the resin can also be used in combination.

In the photosensitive resin composition, the content of the 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 the component (A) is within the above range, a coating film having excellent heat resistance, electrical characteristics and chemical resistance can be obtained.

[(B) Photopolymerizable monomer having an ethylenically unsaturated bond]
(B) As the photopolymerizable monomer having an ethylenically unsaturated bond, a compound having a molecular weight of 1000 or less is preferable, and for example, hydroxyalkyl such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. Mono or di (meth) acrylates of glycols such as (meth) acrylates, ethylene glycol, methoxytetraethylene glycol and polyethylene glycol, (meth) acrylates such as N, N-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide. ) Aminoalkyl (meth) acrylates such as acrylamides and N, N-dimethylaminoethyl (meth) acrylates, hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, tris-hydroxyethyl isocyanurate, etc. Polyhydric alcohols or polyvalent (meth) acrylates of these ethylene oxide or propylene oxide adducts, ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth) acrylates and polyethoxydi (meth) acrylates of bisphenol A. (Meta) acrylates, glycerin diglycidyl ethers, trimethylolpropane triglycidyl ethers, glycidyl ethers (meth) acrylates such as triglycidyl isocyanurate, and melamine (meth) acrylates, acrylamides, acrylonitriles, diacetone acrylamides, styrenes. , Vinyl toluene and the like. These (B) photopolymerizable monomers having an ethylenically unsaturated group may be used alone or in combination of two or more. Further, it is more preferable to use a polyfunctional photopolymerizable monomer having three 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 the compound having such an ethylenically unsaturated bond include trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, and EO / PO-modified trimethylol. Propanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, dipentaerythritol triacrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. Can be mentioned.
The above-mentioned "EO" means "ethylene oxide", and "PO" means "propylene oxide". Further, "EO modification" means having a block structure of an ethylene oxide unit (-CH ₂ -CH ₂ -O-), and "PO modification" means a propylene oxide unit (-CH ₂ -CH (CH ₃ )). -O-) means having a block structure.

[(C) Photopolymerization Initiator]
(C) Examples of the photopolymerization initiator include benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and the like. 1,1-Dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl-1- [4- (methylthio) phenyl] -Acetophenones such as 2-morpholino-1-propanone, N, N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2- Anthraquinones such as aminoanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 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, 4-benzoyl-4'-methyldiphenylsulfide and other benzophenones; 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-Methenylphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) 2,4,5-Triarylimidazole dimer such as -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer, 9-phenylaclydin, Acridins such as 1,7-bis (9,9'-acrydinyl) heptane; acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1,2-octanedione-1- [4-] (Phenylthio) Phenyl] -2- (O-benzoyloxime), 1- [9-ethyl-6- (2-methi) Lubenzoyl) -9H-carbazole-3-yl] oxime esters such as etanone 1- (O-acetyloxime), 1-phenyl-1,2-propanedione-2- [O- (ethoxycarbonyl) oxime] Can be mentioned. These (C) photopolymerization initiators may be used alone or in combination of two or more. In addition, Irgacure 819 (manufactured by BASF Japan, trade name, "Irgacure" is a registered trademark), which has good curability at the bottom for photobleaching, and Irgacure 369 (BASF Japan stock), which is less likely to generate outgas because it is less volatile. Company-made, product name) is preferable.

Further, (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 and the like. The polymerization initiation aid may be used alone or in combination of two or more.

[(D) Inorganic filler]
(D) The inorganic filler will be described. Examples of the inorganic filler (D) include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), titania (TIO ₂ ), titanium oxide (Ta ₂ O ₅ ), zirconia (ZrO ₂ ), and 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 zircate titanate (PZT), Zirconate Zirconate Titanium Lead (PLZT), Gallium Oxide (Ga ₂ O ₃ ), Spinel (MgO ・ Al _{2O 3} ), Murite (3Al _{2O 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 ), zirconia containing itria (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 ), Zirconium Oxide (ZnO), Magnesium Titanium (MgO · TiO ₂ ), Hydrotalcite, mica, calcined kaolin, carbon (C) and the like can be used. These (D) inorganic fillers can be used alone or in combination of two or more.

As the (D) inorganic filler used in the present invention, a silane coupling agent is used in order to disperse the primary particle size in the resin without agglomeration. As the silane coupling agent, generally available ones can be used, for example, alkylsilane, alkoxysilane, vinylsilane, epoxysilane, aminosilane, acrylicsilane, methacrylicsilane, mercaptosilane, sulfidesilane, isocyanatesilane, and the like. Sulfersilane, styrylsilane, alkylchlorosilane and the like can be used. Specific compound names include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, diisopropyldimethoxysilane, and isobutyltrimethoxy. Silane, diisobutyldimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-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, vinyltri Acetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, allyltrimethoxysilane, diallyldimethylsilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxy Propyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, N- (1,3-dimethylbutylidene) -3-aminopropyltriethoxysilane, aminosilane , Monomethyltriisocyanatesilane, tetraisocyanatesilane, γ-isocyanatepropyltriethoxysilane. The preferred silane coupling agent to be used is one that reacts with the carboxylki group of the (A) acid-modified vinyl group-containing epoxy resin contained in the photosensitive resin composition, and examples thereof include epoxysilane, acrylicsilane, and methacryl. Silane is preferred. Since these silane coupling agents strengthen the bond between silica and the resin, they strengthen the strength of the film when used as a permanent mask resist, and contribute to crack resistance in the temperature cycle test and the like. Further, mercaptosilane and isocyanatesilane may be used. (B) It is considered that the photopolymerizable monomer having an ethylenically unsaturated bond reacts with the ethylenically unsaturated group to exert the same effect as when the silane coupling agent is used.

In the photosensitive resin composition, the content of the 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 thermal expansion rate, but 40 to 65. It is preferably by mass, more preferably 45 to 60% by mass. When the content of the component (D) is within the above range, low thermal expansion rate, heat resistance, electrical reliability (HAST resistance), heat impact resistance, resolution, film strength and the like can be further improved. .. If the filling amount exceeds 70% 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, it tends to be difficult to obtain crack resistance at the time of reflow mounting.

The average particle size of the inorganic filler (D) is preferably 0.01 to 1 μm, more preferably 0.1 to 1 μm from the viewpoint of practicality and resolution, and 0.3 to 0.7 μm. Most preferably. The maximum particle size of the (D) inorganic filler is preferably 0.1 to 5 μm, more preferably 0.1 to 3 μm, and 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.

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

When the 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, the low expansion rate, the solder heat resistance, and the adhesive strength between the underfill material and the cured film after the PCT resistance test can be further improved.

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 above-mentioned components (A) to (D). Further, (H) an epoxy resin curing agent may be contained. Hereinafter, each component will be described.

[(E) Pigment]
The photosensitive resin composition preferably contains a pigment as the component (E). The pigment (E) is preferably used according to a desired color in order to improve the distinctiveness and appearance of the manufacturing apparatus and when concealing a wiring pattern. The pigment (E) is used as needed according to a desired color, and a colorant that develops a desired color may be appropriately selected and used. Examples of the colorant include phthalocyanine blue and phthalocyanine. Known colorants such as green, iodin green, diazo yellow, and crystal violet are preferable.
The content of the (E) pigment having a total solid content of 100 parts by mass in the photosensitive resin composition is preferably 0.1 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass. When the content of the component (E) is within the above range, the wiring pattern can be concealed.

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

Examples of the (F) curing agent include thermosetting compounds such as epoxy compounds, melamine compounds, urea compounds, oxazoline compounds, and block-type isocyanates. Examples of the epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, novolak type epoxy resin, bisphenol S type epoxy resin, and biphenyl type epoxy resin. , Naphthalene type epoxy resin, dicyclo type epoxy resin, hydantin type epoxy resin, heterocyclic epoxy resin such as triglycidyl isocyanurate, bixirenol type epoxy resin and the like.
Examples of the melamine compound include triaminotriazine, hexamethoxymelamine, and hexabutoxyd melamine.
Examples of the urea compound include dimethylol urea and the like.

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

Examples of the isocyanate blocking agent include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-palerolactam, γ-butyrolactam and β-propiolactam; Active oxime-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; oxime-based blocking agents such as formaldehyde xim, acetoaldoxime, acetoxime, methylethylketoxim, diacetylmonooxime and cyclohexaneoxime. Mercaptan-based blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol, ethylthiophenol; acid amide-based blocking agents such as acetate amide and benzamide; imides such as succinic acid imide and maleate imide. Examples thereof include 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.

(F) 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, and contains the epoxy compound and the block-type isocyanate. It is more preferable to use them together.

(F) The curing agent may be used alone or in combination of two or more. (F) When a curing agent is used, the content thereof 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. It is more preferably 5 to 20% by mass. (F) By setting the content of the curing agent in the range of 2 to 40% by mass, the heat resistance of the formed cured film can be further improved while maintaining good developability.

[(G) Elastomer]
The elastomer (G) can be suitably used when the photosensitive resin composition of the present invention is used for a semiconductor package substrate. By adding the (G) elastomer to the photosensitive resin composition of the present invention, the bridging reaction (curing reaction) proceeds due to ultraviolet rays or heat, and the (A) acid-modified vinyl group-containing epoxy resin is cured and shrunk. It is possible to solve the problem that strain (internal stress) is applied to the inside of the resin and the flexibility and adhesiveness are lowered.

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

Examples of the styrene-based elastomer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, 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 the components constituting the styrene-based elastomer. More specifically, Toughprene, Solplene T, Asaplen T, Toughtech (above, manufactured by Asahi Kasei Co., Ltd.), Elastomer AR (manufactured by Aron Kasei Co., Ltd.), Clayton G, Califlex (above, manufactured by Clayton Polymer Japan Co., Ltd.), JSR-TR, TSR-SIS, Dynalon (manufactured by JSR Corporation), Denka STR (manufactured by Denka Co., Ltd.), Quintac (manufactured by Nippon Zeon Co., Ltd.), TPE-SB series (manufactured by Sumitomo Chemical Co., Ltd.), Lavalon (Mitsubishi Chemical Co., Ltd.), Septon, Hybler (above, Claret Co., Ltd.), Sumiflex (Sumitomo Bakelite Co., Ltd.), Elastomer, Actimer (above, Riken Technos Co., Ltd.), etc. can be used.

The olefin-based elastomer is a copolymer of α-olefin having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, and 4-methyl-pentene. Specific examples thereof include ethylene-propylene copolymer (EPR), ethylene-propylene-diene copolymer (EPDM), dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylenenorbornene, ethylidenenorbornene, butadiene, and the like. Examples thereof include a non-conjugated diene having 2 to 20 carbon atoms such as isoprene, an α-olefin copolymer, and a carboxy-modified NBR obtained by copolymerizing a butadiene-acrylonitrile copolymer with methacrylic acid. More specifically, ethylene / α-olefin copolymer rubber, ethylene / α-olefin / non-conjugated diene copolymer rubber, propylene / α-olefin copolymer rubber, butene / α-olefin copolymer rubber Can be mentioned. Further, specifically, Mirastoma (manufactured by Mitsui Chemicals Co., Ltd.), EXACT (manufactured by Exxon Mobile Co., Ltd.), ENGAGE (manufactured by Dow Chemical Co., Ltd.), 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), epoxidation with partially epoxidized polybutadiene Polybudadiene BF-1000 (manufactured by Nippon Soda Co., Ltd.), PB-3600 (manufactured by Daicel Co., Ltd.) and the like can be used.

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

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

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

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

Examples of the polyester-based elastomer include those obtained by polycondensing a dicarboxylic acid or a derivative thereof and a diol compound or a derivative thereof.
Specific examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and aromatic dicarboxylic acids in which the hydrogen atom of these aromatic nuclei is substituted with a methyl group, an ethyl group, a phenyl group, or the like. Examples thereof include aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid and dodecanedicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. These compounds may be used alone or in combination of two or more.
Specific examples of the diol compound include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, and 1,4-cyclohexanediol. And an alicyclic diol, or a divalent phenol represented by the following general formula (4) can be mentioned.

［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 the 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, and r represents 0 or 1. ]

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

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

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

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

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

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

In addition to the above-mentioned elastomer, a rubber-modified epoxy resin can also be used. The rubber-modified epoxy resin is, for example, a bisphenol F type epoxy resin, a bisphenol A type epoxy resin, a salicylaldehyde type epoxy resin, a phenol novolac type epoxy resin, or a part or all of the epoxy groups of the cresol novolac type epoxy resin. It is obtained by modifying with an acid-modified butadiene-acrylonitrile rubber, a terminal amino-modified silicone rubber, or the like. Among these elastomers, in terms of shear adhesion, both-terminal carboxyl group-modified butadiene-acrylonitrile copolymer, esper (Esper 1612, 1620), which is a polyester elastomer having a hydroxyl group, and epoxidation Polybudadiene and the like are preferable. Further, an elastomer that is liquid at room temperature (25 ° C.) is particularly preferable.

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

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

Specific examples of such (H) epoxy resin curing agent include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-. Imidazole derivatives such as methyl-5-hydroxymethylimidazole; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenedamine, diaminodiphenylsulphon, dicyandiamide, urea, urea derivatives, melamine, polybase hydrazide Polyamines such as; these organolates and / or epoxyadducts: amine complexes of boron trifluoride; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xylylyl. Triazine derivatives such as -S-triazine; trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholin, hexa (N-methyl) melamine, 2,4,6 -Tertiary amines such as tris (dimethylaminophenol), tetramethylguanidine, m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac; tributylphosphine, triphenylphosphine, tris- Organic phosphines such as 2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide, hexadecyltributylphosnium chloride; quaternary grades such as benzyltrimethylammonium chloride and phenyltributylammonium chloride. Ammonium salts; the above-mentioned polybasic acid anhydrides; diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrilium hexafluorophosphate and the like. These (H) epoxy resin curing agents may be used alone or in combination of two or more.

(H) When the epoxy resin curing agent is used, the content thereof is preferably 0.01 to 20% by mass, preferably 0.1 to 10% by mass, based on the total solid content of the photosensitive resin composition. It is more preferable to have.

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

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

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

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

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

The photosensitive resin composition of the present invention has characteristics and reliability required for solder resists, interlayer insulating films, semiconductor surface protective films, etc. provided in printed wiring boards such as rigid wiring boards and flexible wiring boards, and package substrates. Can be satisfied. The solder resist obtained from the photosensitive resin composition of the present invention is sufficiently excellent in heat and impact resistance, and also has alkali resistance, solder heat resistance, and electrolytic Ni / Au plating resistance due to the same factors. It is also excellent in mechanical properties such as elongation and tensile strength, as well as HAST resistance.

[Photosensitive film]
Hereinafter, preferred embodiments of the photosensitive film of the present invention will be described. The photosensitive film includes 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-mentioned photosensitive resin composition in a solvent (diluent) as described above to prepare a solution having a solid content of about 30 to 70% by mass, and then applying such a solution on the support layer. It is preferably formed by applying to and drying. The above coating can be performed by a known method using, for example, a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, a bar coater, or the like. The thickness of the photosensitive layer varies depending on the intended use, but is preferably 5 to 100 μm, more preferably 10 to 60 μm, after drying with the diluent removed by heating and / or blowing with hot air. If the thickness is less than 5 μm, coating tends to be difficult industrially, 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 a polymer film having heat resistance and solvent resistance 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 from the photosensitive film before development, and if it exceeds 100 μm, the resolution and flexibility tend to decrease. In the present embodiment, since the photosensitive layer is formed by using the polyester resin as described above, the thickness of the support layer is thicker than that of the conventional one, for example, when it is more than 25 μm and 100 μm or less. Can also maintain its flexibility and resolution.

Examples of the protective film layer include a polyethylene film, a polypropylene film, a polyethylene terephthalate film, and surface-treated paper. The protective film layer preferably has a smaller adhesive force between the photosensitive layer and the protective film layer than the adhesive force 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 into a winding core with the protective film layer interposed therebetween, for example. Can be rolled up and stored.

[Resist pattern forming method, printed wiring board]
In the method for forming a resist pattern of the present invention, a photosensitive resin composition is used on an insulating substrate of a laminated substrate including an insulating substrate and a conductor layer having a circuit pattern formed on the insulating substrate so as to cover the conductor layer. The photosensitive layer is laminated, and a predetermined portion of the photosensitive layer is irradiated with an active light beam to form an exposed portion, and then a portion other than the exposed portion of the photosensitive layer is 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-mentioned 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 laminating or the like. From the viewpoint of improving adhesion and followability, a method of laminating under reduced pressure is also preferable. The photosensitive resin composition can also be applied onto the substrate by a known method such as a screen printing method or a method of applying the varnish of the photosensitive resin composition by a roll coater. Next, an exposure step is performed in which a predetermined portion of the photosensitive resin composition layer is irradiated with active light through a mask pattern and the photosensitive resin composition layer of the irradiated portion is photocured.

As the light source of the active light, a known light source, for example, a carbon arc lamp, a mercury vapor arc lamp, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, or the like that effectively emits ultraviolet rays is used. In addition, a flood bulb for photography, a solar lamp, or the like that effectively radiates visible light or ultraviolet light is also used.

Further, if a support is present on the photosensitive layer, the support is removed, and then a portion (unexposed portion) that has not been photo-cured by wet development or dry development is removed for development. A resist pattern can be formed. In the case of the above wet development, as the developing solution, for example, an alkaline aqueous solution such as sodium hydroxide, an aqueous developer, an organic solvent or the like, which is safe, stable and has good operability is used. Development methods include dip method, battle method, spray method, high pressure spray method, brushing, slapping and the like.

After the development step is completed, it is preferable to irradiate with ultraviolet rays or heat with a high-pressure mercury lamp for the purpose of improving solder heat resistance, chemical resistance and the like. When irradiating with ultraviolet rays, the irradiation amount can be adjusted as needed, and for example, irradiation can be performed with an irradiation amount of about 0.05 to 10 J / cm ² . When the resist pattern is heated, it is preferably carried out in the range of about 130 to 200 ° C. for about 15 to 90 minutes.

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

The permanent resist formed in this way also serves as a protective film for wiring after soldering to the substrate, and has various characteristics of solder resist, and is used for printed wiring boards, semiconductor package boards, and flexible wiring boards. It can be used as a solder resist. The solder resist is used, for example, as a plating resist or an etching resist when plating or etching a substrate, or is left as it is on the substrate and is used as a protective film for protecting wiring or the like.

The substrate provided with the permanent resist is then mounted on a semiconductor element or the like (for example, wire bonding or solder connection) and then mounted on an electronic device such as a personal computer.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

For example, in another embodiment of the photosensitive film of the present invention, the photosensitive film and the support layer may be provided without the 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 an insulating substrate or on both sides of the insulating substrate. In that case, the photosensitive resin composition of the present invention may be used. The cured product of the material functions as an interlayer insulating film for reliably insulating the conductive layers.

Moreover, you may use the photosensitive resin composition of this invention in the manufacturing method of a printed wiring board. For example, a method for manufacturing a printed wiring board comprising an insulating substrate, a conductor layer having a circuit pattern formed on the insulating substrate, and a permanent resist layer formed so as 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 active light to form an exposed portion, and then an exposed portion is formed. , A method of manufacturing a printed wiring board, etc., in which a portion other than the exposed portion is removed.

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: Production of acid-modified vinyl group-containing epoxy resin (A-1, 2, 3, 4)]
Bisphenol F novolac type epoxy resin (EXA-7376, manufactured by DIC Co., Ltd.) having a structural unit ( R ¹³ = hydrogen atom, Y ³ = glycidyl group) represented by the general formula (3) , 350 parts by mass, 70 mass of acrylic acid A part, 0.5 part by mass of methylhydroquinone, 120 parts by mass of carbitol acetate, and a catalyst (triphenylphosphine) were charged and reacted by heating at 90 ° C. and stirring to completely dissolve the mixture. Next, the obtained solution was cooled to 60 ° C., 2 parts by mass of triphenylphosphine was added, and the mixture was heated to 100 ° C. and reacted until the acid value of the solution reached 1 mgKOH / g. To the solution after the reaction, 98 parts by mass of tetrahydrophthalic anhydride (THPAC) and 85 parts by mass of carbitol acetate were added, heated to 80 ° C., reacted for about 6 hours, and then cooled to have a solid content concentration of 73 parts by mass. % (A) THPAC-modified bisphenol F-type novolak epoxy acrylate (hereinafter, "acid-modified vinyl group-containing epoxy resin (A-1, 2, 3, 4) (dispersity; A-1 = 6.0)" , A-2 = 4.5, A-3 = 3.5, A-4 = 2.5). Here, the amount of catalyst (0 to 2 parts by mass) and the heating temperature (80). ~ 120 ° C.), and the time was changed to obtain resins having different dispersities.

(Measurement of dispersion)
For the number average molecular weight (Mn), weight average molecular weight (Mw) and Mw / Mn (dispersity) of THPAC-modified bisphenol F-type novolak epoxy acrylate, a chromatogram of the molecular weight distribution of THPAC-modified bisphenol F-type novolak epoxy acrylate is obtained by GPC (gel). It was measured by permeation chromatography) and converted from the elution time of standard polystyrene at 25 ° C. EcoSEC and HLC-8320GPC manufactured by Tosoh Corporation were used as the measuring device, tetrahydrofuran was used as the eluent for GPC, and Gelpack GL-A-150 and Gelpack GL-A-10 (Gelpack GL-A-10) were used as the columns. The product directly connected to Hitachi High-Technologies Corporation (trade name) was used.

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

The details of each material in Table 1 are as follows.
[(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 produced in the synthetic example (dispersity Mw / Mn = 6.0)
* 2 (Acid-modified vinyl group-containing epoxy resin (A-2)): THPAC-modified bisphenol F-type novolak epoxy acrylate produced in the synthetic example (dispersity Mw / Mn = 4.5)
* 3 (Acid-modified vinyl group-containing epoxy resin (A-3)): THPAC-modified bisphenol F-type novolak epoxy acrylate produced in the synthetic example (dispersity Mw / Mn = 3.5)
* 4 (Acid-modified vinyl group-containing epoxy resin (A-4)): THPAC-modified bisphenol F-type novolak epoxy acrylate produced in the synthetic example (dispersity Mw / Mn = 2.5)
[(B) Photopolymerizable monomer having an ethylenically unsaturated bond]
* 5 (Aronix M402): Dipentaerythritol hexaacrylate (manufactured by Toagosei Co., Ltd.)
[(C) Photopolymerization Initiator)]
* 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 particle 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 & Sumitomo Metal Corporation)
* 10 (RE-306): Epoxy resin (phenol novolac type epoxy resin, manufactured by Nippon Kayaku Co., Ltd.)
[(G) Elastomer]
* 11 (PB-3600): Epoxidized polybutadiene (manufactured by Daicel Corporation)

[Silica residue]
The photosensitive resin compositions of Examples and Comparative Examples were applied to a copper-clad laminated substrate (MCL-E-67, glass cloth base epoxy resin substrate, manufactured by Hitachi Kasei Co., Ltd.) so that the film thickness after drying was 15 μm. After being applied by a screen printing method, it was dried at 75 ° C. for 30 minutes using a hot air circulation type dryer. The obtained coating film is irradiated with ultraviolet rays having an integrated exposure amount of 100 mJ / cm ² through a negative film having a diameter of 80 μm scattered on an area of 1 × 1 cm square, and a 1% by mass sodium carbonate aqueous solution is applied. For 60 seconds, spray development was performed at a pressure of 1.8 kgf / cm ² , and the unexposed portion was melt-developed to form an image. Then, the opening was observed at a magnification of 10,000 times using SEM (manufactured by High Technologies Co., Ltd., model number: S4200, field emission scanning electron microscope), and the remaining state of the silica residue was evaluated according to the following criteria. The evaluation results are shown in Table 2.
A: 1 or less silica residue in 1 field of view B: 2 or more and less than 10 silica residues in 1 field of view C: 10 or more silica residues in 1 field of view

[HAST resistance evaluation]
Etching the copper surface of a printed wiring board substrate (MCL-E-679, glass cloth substrate high Tg epoxy resin substrate, manufactured by Hitachi Kasei Co., Ltd., trade name) in which a 12 μm thick copper foil is laminated on a glass epoxy substrate. Formed a comb-shaped electrode having a line / space of 28 μm / 32 μm. Using this substrate as an evaluation substrate, a cured product of resist was formed on the substrate as described above, and then exposed under the conditions of 135 ° C., 85% RH, and DC 5V for 200 hours. Then, the degree of migration was observed with a 100x metallurgical microscope and evaluated according to the following criteria.
That is, if migration did not occur in the permanent resist film and the resistance value did not decrease, it was set as "3", and if the resistance value did not decrease, it was set as "2", and large migration occurred. Those with a reduced resistance value were evaluated as "1".
The evaluation results are shown in Table 2.

[Evaluation of thermal expansion rate / glass transition point (Tg)]
The photosensitive resin composition solution is 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 is 30 μm. Was dried at 75 ° C. for about 30 minutes using a hot air convection dryer. Subsequently, a polyethylene film (NF-15, manufactured by Tamapoli Co., Ltd., trade name) is attached as a protective film on the surface of the photosensitive resin composition layer on the side opposite to the side in contact with the support, and the photosensitive resin composition layer is photosensitive. I got a film. The entire surface of the photosensitive film was exposed, and then the film was allowed to stand at room temperature (25 ° C.) for 1 hour, then the polyethylene film was peeled off and spray-developed with a 1% by mass sodium carbonate aqueous solution at 30 ° C. After spray development, ultraviolet irradiation of 2 J / cm ² was performed using an ultraviolet irradiation device manufactured by ORC Manufacturing Co., Ltd., and further heat treatment was performed 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 photosensitive resin cured product (test piece) for evaluation of the coefficient of thermal expansion. .. The coefficient of thermal expansion ( ^10-6 / ° C., ppm) was measured in the tensile mode using a TMA device (thermomechanical analyzer) SS6000 (manufactured by Seiko Instruments Inc.). 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 device, heated from room temperature (25 ° C.) to 160 ° C., and left for 15 minutes. Then, the mixture was cooled to −60 ° C. and measured from −60 ° C. to 250 ° C. under the condition of a heating rate of 10 ° C./min to measure the glass transition point and the thermal expansion rate. The evaluation results are shown in Table 2.

As is clear from Table 2, it can be seen that Examples 1 to 3 are excellent in general properties such as silica residue, electrical reliability (HAST resistance), low thermal expansion rate, and high Tg. Further, it can be seen that the acid-modified vinyl group-containing epoxy resin having a dispersity of 3.5 or less has a particularly small amount of silica residue and is excellent in thermal expansion rate and heat resistance. On the other hand, as is clear from Table 2, it can be seen that Comparative Examples 1 to 4 have insufficient silica residue and electrical reliability. Therefore, according to the photosensitive resin composition of the present invention, a permanent mask resist having a low thermal expansion rate, excellent HAST resistance, and a high Tg can be obtained while maintaining a small amount of 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. Yes, the acid-modified vinyl group-containing epoxy resin of the component (A) contains an epoxy resin (a), which is a bisphenol type novolak resin having a structural unit represented by the following general formula (2) or (3), and a vinyl group. A resin (A'') obtained by reacting a resin (A') obtained by reacting with a monocarboxylic acid (b) with a saturated or unsaturated group-containing polybasic acid anhydride (however, Mw / Mn (where Mw / Mn) The degree of dispersion expressed in (weight average molecular weight / number average molecular weight) is 2.0 to 5.0. Further, after reacting the o-cresol novolak resin with acrylic acid, tetrahydrophthalic anhydride is reacted. (Excluding resins made by reacting o-cresol novolak resin with acrylic acid and pentaerythritol triacrylate / succinic anhydride adduct, and then reacting with succinic anhydride and tetrahydrophthalic anhydride). Moreover, (A) the content of the acid-modified vinyl group-containing epoxy resin is 29 to 60% by mass with respect to the total solid content, and (D) the content of the inorganic filler is 30 to 70% by mass with respect to the total solid content. % Is a photosensitive resin composition.

[In the general formula (2), R ¹² represents a hydrogen atom or a methyl group, and Y ² independently represents a hydrogen atom or a glycidyl group. The two R ^12s may be the same or different. However, at least one of Y ² shows a glycidyl group. In the general formula (3), R ¹³ represents a hydrogen atom or a methyl group, and Y ³ independently represents a hydrogen atom or a glycidyl group. The two R ^13s may be the same or different. However, at ^least one of Y3 shows a glycidyl group. ] (B) The photosensitive resin composition according to claim 1, wherein the photopolymerizable monomer having an ethylenically unsaturated bond is a polyfunctional photopolymerizable monomer having three or more ethylenically unsaturated bonds in one molecule. The photosensitive resin composition according to claim 1 or 2, 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. The photosensitive according to any one of claims 1 to 3 so as to cover the conductor layer on the insulating substrate of a laminated substrate including an insulating substrate and a conductor layer having a circuit pattern formed on the insulating substrate. It is characterized in that a photosensitive layer is laminated using a sex resin composition, a predetermined portion of the photosensitive layer is irradiated with active light to form an exposed portion, and then a portion of the photosensitive layer other than the exposed portion is removed. A method for forming a resist pattern. It is formed by using the insulating substrate, the 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. A printed wiring board with a permanent resist layer.