JP2020144374A - Photosensitive resin composition, dry film, printed wiring board, and production method of photosensitive resin composition - Google Patents

Abstract

To provide a photosensitive resin composition having excellent developability with an alkali aqueous solution and giving a cured product having high electric insulation property and plating durability.SOLUTION: The photosensitive resin composition comprises a carboxyl group-containing resin, an unsaturated compound having at least one ethylenically unsaturated bond in one molecule, a photopolymerization initiator and an epoxy compound, in which the carboxyl group-containing resin comprises a carboxyl group-containing resin that is a reaction product of an acid anhydride and an intermediate which is a reaction product of an epoxy compound having a bisphenol fluorene skeleton represented by the following formula (1) and an unsaturated group-containing carboxylic acid; the content of the unsaturated compound with respect to the carboxyl group-containing resin is 21 to 40 mass%; and the epoxy compound comprises a crystalline epoxy resin.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing a photosensitive resin composition, a dry film, a printed wiring board, and a carboxyl group-containing resin. Specifically, the printed wiring board has a solder resist layer, a plated resist layer, an etching resist layer, an interlayer insulating layer, and the like. A photosensitive resin composition for forming an electrically insulating layer, a dry film containing the photosensitive resin composition, and a printed wiring board provided with an interlayer insulating layer containing a cured product of the photosensitive resin composition. The present invention relates to a printed wiring board provided with a solder resist layer containing a cured product of the photosensitive resin composition, and a method for producing the photosensitive resin composition.

Conventionally, for the production of printed wiring boards, various electrically insulating resin compositions have been used to form electrically insulating layers such as a solder resist layer, a plated resist layer, an etching resist layer, and an interlayer insulating layer. As the resin composition, for example, a photosensitive resin composition is used.

In order to impart high heat resistance to the layer formed from the photosensitive resin composition, it has been proposed to add a carboxyl group-containing resin having a bisphenol fluorene skeleton to the photosensitive resin composition. For example, Patent Document 1 discloses the use of a carboxyl group-containing resin having a fluorene skeleton obtained by reacting a fluorene epoxy (meth) acrylate with a polyvalent carboxylic acid or an anhydride thereof.

However, when a carboxyl group-containing resin having a bisphenol fluorene skeleton is blended with the photosensitive resin composition, there is a problem that the developability of the photosensitive resin composition is lowered. When the developability of the photosensitive resin composition is low, it becomes difficult to form an electrically insulating layer having a sufficient thickness by a photolithography method.

Japanese Patent No. 4508929

The present invention has been made in view of the above reasons, and is a photosensitive resin composition having excellent developability while containing a carboxyl group-containing resin having a bisphenol fluorene skeleton, and a dry containing the photosensitive resin composition. A film, a printed wiring board having an interlayer insulating layer containing a cured product of the photosensitive resin composition, a printed wiring board having a solder resist layer containing a cured product of the photosensitive resin composition, and the photosensitive resin composition. The purpose is to provide a manufacturing method.

The photosensitive resin composition according to the present invention includes a carboxyl group-containing resin (A) and
An unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule,
Photopolymerization initiator (C) and
Containing with epoxy compound (D),
The carboxyl group-containing resin (A) is represented by the following formula (1), and in the formula (1), R _{1 to} R ₈ are independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen, bisphenol fluorene. It contains an intermediate which is a reaction product of an epoxy compound (a1) having a skeleton, an unsaturated group-containing carboxylic acid (a2), and a carboxyl group-containing resin (A1) which is a reaction product of an acid anhydride.
The content of the unsaturated compound (B) with respect to the carboxyl group-containing resin (A) is 21 to 40% by mass.
The epoxy compound (D) contains a crystalline epoxy resin.

The dry film according to the present invention contains the photosensitive resin composition.

The printed wiring board according to the present invention includes an interlayer insulating layer containing a cured product of the photosensitive resin composition.

The printed wiring board according to the present invention includes a solder resist layer containing a cured product of the photosensitive resin composition.

The method for producing a photosensitive resin composition according to the present invention is
Represented by the following formula (1), in the formula (1), R _{1 to} R ₈ are independently hydrogen, an epoxy compound (a1) having a bisphenol fluorene skeleton which is an alkyl group having 1 to 5 carbon atoms or a halogen, and The unsaturated group-containing carboxylic acid (a2) was reacted, and the resulting intermediate was mixed with an acid anhydride containing at least one of an acid dianhydride (a3) and an acid monoanhydride (a4). By reacting, a carboxyl group-containing resin (A1) is synthesized.
The carboxyl group-containing resin (A) containing the carboxyl group-containing resin (A1) and
An unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule,
Photopolymerization initiator (C) and
Including mixing with epoxy compound (D)
The content of the unsaturated compound (B) with respect to the carboxyl group-containing resin (A) is 21 to 40% by mass.
The epoxy compound (D) contains a crystalline epoxy resin.

According to the present invention, a photosensitive resin composition containing a carboxyl group-containing resin having a bisphenol fluorene skeleton and having excellent developability, a dry film containing the photosensitive resin composition, and the photosensitive resin composition. A printed wiring board having an interlayer insulating layer containing a cured product of the above, a printed wiring board having a solder resist layer containing a cured product of the photosensitive resin composition, and a method for producing the photosensitive resin composition can be obtained.

1A to 1E are cross-sectional views showing a process of manufacturing a multilayer printed wiring board.

A mode for carrying out the present invention will be described. In the following description, "(meth) acrylic" means at least one of "acrylic" and "methacrylic". For example, (meth) acrylate means at least one of acrylate and methacrylate.

The photosensitive resin composition according to the present embodiment includes a carboxyl group-containing resin (A), an unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule, and a photopolymerization initiator (C). And the epoxy compound (D).

The carboxyl group-containing resin (A) contains a carboxyl group-containing resin (A1). This carboxyl group-containing resin (A1) is represented by, for example, the following formula (1), and in the formula (1), R _{1 to} R ₈ are independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen, respectively. It is a reaction product of an epoxy compound (a1) having a bisphenol fluorene skeleton, an intermediate which is a reaction product of an unsaturated group-containing carboxylic acid (a2), and an acid anhydride. This carboxyl group-containing resin (A1) is obtained, for example, by reacting an epoxy compound (a1) having a bisphenol fluorene skeleton represented by the following formula (1) with an unsaturated group-containing carboxylic acid (a2). It is synthesized by reacting the intermediate with an acid anhydride.

In the formula (1), R _{1 to} R ₈ are independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen. That is, each of R _{1 to} R ₈ in the formula (1) may be hydrogen, but may be an alkyl group having 1 to 5 carbon atoms or a halogen. Even if hydrogen in the aromatic ring is replaced with a low molecular weight alkyl group or halogen, the physical properties of the carboxyl group-containing resin (A1) are not adversely affected, but rather the substitution causes the photosensitivity containing the carboxyl group-containing resin (A1). This is because the heat resistance or flame retardancy of the cured product of the sex resin composition may be improved.

In the present embodiment, the carboxyl group-containing resin (A1) has a bisphenol fluorene skeleton represented by the formula (1) derived from the epoxy compound (a1), so that the photosensitive resin composition containing the carboxyl group-containing resin (A1) is contained. High heat resistance and insulation reliability can be imparted to the cured product.

In the present embodiment, the content of the unsaturated compound (B) with respect to the carboxyl group-containing resin (A) is in the range of 21 to 40% by mass. This makes it possible to improve the developability of the photosensitive resin composition while imparting excellent photocurability to the photosensitive resin composition, and suppress the tackiness of the film formed from the photosensitive resin composition. can do. That is, when the content of the unsaturated compound (B) with respect to the carboxyl group-containing resin (A) is 21% by mass or more, the photocurability of the photosensitive resin composition portion is improved, and the photosensitive resin composition is developed. The sex can be improved. Further, when the content of the unsaturated compound (B) with respect to the carboxyl group-containing resin (A) is 40% by mass or less, the tackiness of the film formed from the photosensitive resin composition is suppressed.

In the present embodiment, since the epoxy compound (D) contains a crystalline epoxy resin, the developability of the photosensitive resin composition can be improved, and the photosensitive resin composition can be prepared with an alkali metal salt and an alkali metal water. It can also be developed with an alkaline aqueous solution containing at least one of the oxides.

Further, the content of the unsaturated compound (B) with respect to the carboxyl group-containing resin (A) is in the range of 21 to 40% by mass, and the epoxy compound (D) contains the crystalline epoxy resin. Excellent resolution can be obtained.

From these facts, the photosensitive resin composition of the present embodiment has excellent developability while containing a carboxyl group-containing resin (A1) having a bisphenol fluorene skeleton.

Hereinafter, the photosensitive resin composition of the present embodiment will be described in more detail.

First, the carboxyl group-containing resin (A1) contained in the carboxyl group-containing resin (A) will be described more specifically. In order to synthesize the carboxyl group-containing resin (A1), first, at least a part of the epoxy group (see formula (2)) in the epoxy compound (a1) having a bisphenol fluorene skeleton represented by the formula (1) and unsaturated. An intermediate is synthesized by reacting with a group-containing carboxylic acid (a2). The intermediate has a structure represented by the following formula (3) generated by a cycloaddition reaction between an epoxy group and an unsaturated group-containing carboxylic acid (a2). That is, the intermediate has a secondary hydroxyl group generated by a cycloaddition reaction between an epoxy group and an unsaturated group-containing carboxylic acid (a2) in the structure represented by the formula (3). In formula (3), A is an unsaturated group-containing carboxylic acid residue.

Next, the secondary hydroxyl group of the intermediate is reacted with the acid anhydride. The acid anhydride contains, for example, at least one of an acid dianhydride (a3) and an acid monoanhydride (a4). When the acid anhydride contains an acid dianhydride (a3) and an acid dianhydride (a4), for example, a part of the secondary hydroxyl groups in the intermediate is reacted with the acid dianhydride (a3). Then, another part of the secondary hydroxyl groups in the intermediate is reacted with the acid dianhydride (a4). As a result, the carboxyl group-containing resin (A1) can be synthesized. Therefore, the carboxyl group-containing resin (A1) has a bisphenol fluorene skeleton represented by the formula (1), and when the acid anhydride contains the acid anhydride (a4), the structure represented by the following formula (4). When the acid anhydride contains an acid dianhydride (a3), it also has a structure represented by the following formula (5).

The structure represented by the formula (4) is formed by the reaction of the secondary hydroxyl group in the structure represented by the formula (3) of the intermediate with the acid anhydride group in the acid anhydride (a4). In formula (4), A is an unsaturated group-containing carboxylic acid residue and B is an acid monoanhydride residue.

The structure represented by the formula (5) is formed by the reaction between the two acid anhydride groups in the acid dianhydride (a3) and the two secondary hydroxyl groups in the intermediate. That is, the structure represented by the formula (5) is formed by cross-linking the two secondary hydroxyl groups with the acid dianhydride (a3). In addition, there are cases where two secondary hydroxyl groups existing in one molecule of the intermediate are crosslinked, and cases where two secondary hydroxyl groups existing in each of the two molecules of the intermediate are crosslinked. But it is possible. When the two secondary hydroxyl groups present in each of the two molecules of the intermediate are crosslinked, an increase in molecular weight is obtained. In formula (5), A is an unsaturated group-containing carboxylic acid residue and D is an acid dianhydride residue.

The carboxyl group-containing resin (A1) may further have a structure represented by the following formula (6). The structure represented by the formula (6) is formed by reacting only one of the two acid anhydride groups in the acid dianhydride (a3) with the secondary hydroxyl group in the intermediate. In formula (6), A is an unsaturated group-containing carboxylic acid residue and D is an acid dianhydride residue.

When a part of the epoxy group in the epoxy compound (a1) remains unreacted during the synthesis of the intermediate, the carboxyl group-containing resin (A1) may have a structure represented by the formula (2), that is, an epoxy group. sell. Further, the carboxyl group-containing resin (A1) may have the structure represented by the formula (3) when a part of the structure represented by the formula (3) in the intermediate remains unreacted.

However, in the present embodiment, by optimizing the reaction conditions at the time of synthesizing the carboxyl group-containing resin (A1), the structure represented by the formula (2) and the formula (6) in the carboxyl group-containing resin (A1) can be obtained. It is possible to reduce or almost eliminate the structures shown.

As described above, the carboxyl group-containing resin (A1) has a bisphenol fluorene skeleton represented by the formula (1), and when the acid anhydride contains the acid anhydride (a4), the structure represented by the formula (4) is obtained. When the acid anhydride contains an acid dianhydride (a3), it also has a structure represented by the formula (5). Further, the carboxyl group-containing resin (A1) may have at least one of a structure represented by the formula (2), a structure represented by the formula (3), and a structure represented by the formula (6).

Further, when the epoxy compound (a1) itself has a secondary hydroxyl group, that is, when n = 1 or more in the formula (7) described later, for example, the carboxyl group-containing resin (A1) is the epoxy compound (a1). ) May have a structure formed by the reaction of the secondary hydroxyl group and the acid anhydride.

The structure of the above-mentioned carboxyl group-containing resin (A1) is reasonably inferred based on common general technical knowledge, and it is not possible to identify the structure of the carboxyl group-containing resin (A1) by analysis. The reason is as follows. When the epoxy compound (a1) itself has a secondary hydroxyl group (for example, when n is 1 or more in the formula (7)), the carboxyl group-containing resin depends on the number of secondary hydroxyl groups in the epoxy compound (a1). The structure of (A1) changes significantly. Further, when the intermediate reacts with the acid dianhydride (a3), as described above, the two secondary hydroxyl groups existing in one molecule of the intermediate are formed by the acid dianhydride (a3). There may be cases where the two secondary hydroxyl groups existing in the two molecules of the intermediate are cross-linked with the acid dianhydride (a3). Therefore, the finally obtained carboxyl group-containing resin (A1) contains a plurality of molecules having different structures from each other, and the structure cannot be identified even by analyzing the carboxyl group-containing resin (A1).

The carboxyl group-containing resin (A1) has a photoreactivity because it has an ethylenically unsaturated group derived from an unsaturated group-containing carboxylic acid (a2). Therefore, the carboxyl group-containing resin (A1) can impart photosensitivity, specifically, ultraviolet curability, to the photosensitive resin composition. Further, the carboxyl group-containing resin (A1) is based on an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide in the photosensitive resin composition because it has a carboxyl group derived from an acid anhydride. Developability can be imparted. Further, when the acid anhydride contains an acid dianhydride (a3), the molecular weight of the carboxyl group-containing resin (A1) is adjusted by being crosslinked by the acid dianhydride (a3). Therefore, a carboxyl group-containing resin (A1) in which the acid value and the molecular weight are appropriately adjusted can be obtained. That is, by controlling the amount of acid dianhydride (a3) and acid monoanhydride (a4) and the amount of acid dianhydride (a4) with respect to the acid dianhydride (a3), the carboxyl group-containing resin (A1) ) Can be easily adjusted in molecular weight and acid value.

The raw material of the carboxyl group-containing resin (A1) and the reaction conditions at the time of synthesizing the carboxyl group-containing resin (A1) will be described in detail.

The epoxy compound (a1) has, for example, a structure represented by the following formula (7). N in the formula (7) is, for example, a number in the range of 0 to 20. In order to appropriately control the molecular weight of the carboxyl group-containing resin (A1), the average of n is particularly preferably in the range of 0 to 1. When the average of n is in the range of 0 to 1, when the acid anhydride contains the acid dianhydride (a3), the excessive increase in molecular weight due to the addition of the acid dianhydride (a3) is likely to be suppressed. ..

The unsaturated group-containing carboxylic acid (a2) can contain, for example, a compound having only one ethylenically unsaturated group. More specifically, the unsaturated group-containing carboxylic acid (a2) includes, for example, acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≈2) monoacrylate, crotonic acid, cinnamic acid, 2-acryloyloxyethyl succinate. Acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl phthalic acid, 2-acryloyloxypropylphthalic acid, 2-methacryloyloxypropylphthalic acid, 2-acryloyloxyethyl maleic acid, 2-methacryloyloxyethyl maleic acid, β-carboxyethyl acrylate, 2-acryloyloxyethyl tetrahydrophthalic acid, 2-methacryloyloxyethyl tetrahydrophthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid, and 2-methacryloyloxyethyl hexahydro It can contain one or more compounds selected from the group consisting of phthalic acids. Preferably, the unsaturated group-containing carboxylic acid (a2) contains acrylic acid.

A known method can be adopted in reacting the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2). For example, an unsaturated group-containing carboxylic acid (a2) is added to a solvent solution of the epoxy compound (a1), and if necessary, a thermal polymerization inhibitor and a catalyst are added and mixed by stirring to obtain a reactive solution. An intermediate can be obtained by reacting this reactive solution by a conventional method at a temperature of preferably 60 to 150 ° C., particularly preferably 80 to 120 ° C. Solvents include, for example, ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, and ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate and propylene glycol monomethyl ether. It can contain at least one component selected from the group consisting of acetic acid esters such as acetate and dialkyl glycol ethers. The thermal polymerization inhibitor contains, for example, at least one of hydroquinone and hydroquinone monomethyl ether. The catalyst is selected from the group consisting of, for example, tertiary amines such as benzyldimethylamine and triethylamine, quaternary ammonium salts such as trimethylbenzylammonium chloride and methyltriethylammonium chloride, triphenylphosphine, and triphenylstibine. Can contain a kind of ingredient.

It is preferred that the catalyst particularly contains triphenylphosphine. That is, it is preferable to react the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2) in the presence of triphenylphosphine. In this case, the ring-opening addition reaction between the epoxy group and the unsaturated group-containing carboxylic acid (a2) in the epoxy compound (a1) is particularly promoted, and the reaction rate (conversion) is 95% or more, 97% or more, or almost 100%. Rate) can be achieved. Therefore, an intermediate having the structure represented by the formula (3) can be obtained in a high yield. In addition, the occurrence of ion migration in the layer containing the cured product of the photosensitive resin composition is suppressed, and the insulation reliability of the layer containing the cured product is further improved.

When the epoxy compound (a1) is reacted with the unsaturated group-containing carboxylic acid (a2), the amount of the unsaturated group-containing carboxylic acid (a2) with respect to 1 mol of the epoxy group of the epoxy compound (a1) is 0.8 to 1. It is preferably in the range of 2 mol. In this case, excellent photosensitivity and storage stability of the photosensitive resin composition can be obtained.

It is also preferable to react the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2) under air bubbling. In this case, the addition polymerization reaction of the unsaturated group can be suppressed, and the increase in the molecular weight of the intermediate and the gelation of the solution of the intermediate can be suppressed. In addition, excessive coloring of the final product, the carboxyl group-containing resin (A1), can be suppressed.

The intermediate thus obtained comprises a hydroxyl group generated by the reaction of the epoxy group in the epoxy compound (a1) and the carboxyl group in the unsaturated group-containing carboxylic acid (a2).

The acid dianhydride (a3) is a compound having two acid anhydride groups. The acid dianhydride (a3) can contain an anhydride of a tetracarboxylic acid. The acid dianhydride (a3) is, for example, 1,2,4,5-benzenetetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, methylcyclohexenetetracarboxylic dianhydride, tetracarboxylic dianhydride, Naphthalene-1,4,5,8-tetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, 9,9'-bis (3,4-dicarboxyphenyl) fluorene dianhydride, glycerin bisuanhydrotri Melitate monoacetate, ethylene glycol bisanehydrotrimericate, 3,3', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5 (tetrahydro) -2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1,3-dione, 1,2,3,4-butanetetracarboxylic dianhydride and 3,3', 4, It can contain at least one compound selected from the group consisting of 4'-biphenyltetracarboxylic dianhydride. In particular, the acid dianhydride (a3) preferably contains 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride. That is, it is preferable that D in the formulas (5) and (6) contains 3,3', 4,4'-biphenyltetracarboxylic dianhydride residue. In this case, while ensuring good developability of the photosensitive resin composition, the tackiness of the film formed from the photosensitive resin composition can be further suppressed, and the insulation reliability and plating resistance of the cured product can be further improved. .. The amount of 3,3', 4,4'-biphenyltetracarboxylic dianhydride is preferably in the range of 20 to 100 mol%, preferably 40 to 100 mol%, based on the whole acid dianhydride (a3). It is more preferably, but not limited to, within the range.

The acid anhydride (a4) is a compound having one acid anhydride group. The acid monoanhydride (a4) can contain an anhydride of a dicarboxylic acid. The acid monoanhydride (a4) is, for example, phthalic anhydride, 1,2,3,6-tetrahydroanhydride, methyltetrahydrophthalic anhydride, methylnadic acid anhydride, hexahydrophthalic anhydride, methylhexa. It can contain one or more compounds selected from the group consisting of hydrophthalic anhydride, succinic anhydride, methylsuccinic anhydride, maleic anhydride, citraconic acid anhydride, glutaric acid anhydride, and itaconic acid anhydride. .. In particular, the acid monoanhydride (a4) preferably contains 1,2,3,6-tetrahydrophthalic anhydride. That is, it is preferable that B in the formula (4) contains 1,2,3,6-tetrahydrophthalic anhydride residue. In this case, while ensuring good developability of the photosensitive resin composition, the tackiness of the film formed from the photosensitive resin composition can be further suppressed, and the insulation reliability and plating resistance of the cured product can be further improved. .. 1,2,3,6-tetrahydrophthalic anhydride is preferably in the range of 20 to 100 mol%, preferably in the range of 40 to 100 mol%, based on the whole acid monoanhydride (a4). Is more preferable, but is not limited to this.

A known method can be adopted in reacting the intermediate with the acid anhydride. For example, an acid anhydride is added to a solvent solution of an intermediate, and if necessary, a thermal polymerization inhibitor and a catalyst are added and mixed by stirring to obtain a reactive solution. The carboxyl group-containing resin (A1) can be obtained by reacting this reactive solution by a conventional method at a temperature of preferably 60 to 150 ° C., particularly preferably 80 to 120 ° C. As the solvent, catalyst and polymerization inhibitor, appropriate ones can be used, and the solvent, catalyst and polymerization inhibitor used at the time of synthesizing the intermediate can also be used as they are.

It is preferred that the catalyst particularly contains triphenylphosphine. That is, it is preferable to react the intermediate with the acid anhydride in the presence of triphenylphosphine. In this case, the reaction between the secondary hydroxyl group and the acid anhydride in the intermediate is particularly promoted, and a reaction rate (conversion rate) of 90% or more, 95% or more, 97% or more, or almost 100% can be achieved. It is possible. Therefore, the carboxyl group-containing resin (A1) having the structure represented by the formula (4) and the structure represented by the formula (5) can be obtained in a high yield. In addition, the occurrence of ion migration in the layer containing the cured product of the photosensitive resin composition is suppressed, and the insulation reliability of the layer containing the cured product is further improved.

It is also preferable to react the intermediate with the acid anhydride under air bubbling. In this case, by suppressing an excessive increase in the molecular weight of the produced carboxyl group-containing resin (A1), the developability of the photosensitive resin composition with an alkaline aqueous solution is particularly improved.

When the acid anhydride contains an acid dianhydride (a4) and an acid monoanhydride (a4), when the intermediate is reacted with the acid dianhydride (a4) and the acid dianhydride (a3), The amount of acid dianhydride (a3) is preferably in the range of 0.05 to 0.24 mol with respect to 1 mol of the epoxy group of the epoxy compound (a1). The amount of acid monoanhydride (a4) is preferably in the range of 0.3 to 0.7 mol with respect to 1 mol of the epoxy group of the epoxy compound (a1). In this case, a carboxyl group-containing resin (A1) in which the acid value and the molecular weight are appropriately adjusted can be easily obtained. Further, by suppressing an excessive increase in the molecular weight of the generated carboxyl group-containing resin (A1), the developability of the photosensitive resin composition with an alkaline aqueous solution is particularly improved.

The carboxyl group-containing resin (A) may contain only the carboxyl group-containing resin (A1), and is a carboxyl group-containing resin other than the carboxyl group-containing resin (A1) (hereinafter, also referred to as a carboxyl group-containing resin (F)). May be further contained.

The carboxyl group-containing resin (F) can contain, for example, a compound having a carboxyl group and no photopolymerizability (hereinafter, referred to as (F1) component). The component (F1) contains, for example, a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group. The ethylenically unsaturated compound having a carboxyl group can contain a compound such as acrylic acid, methacrylic acid, and ω-carboxy-polycaprolactone (n≈2) monoacrylate. The ethylenically unsaturated compound having a carboxyl group can also contain a reaction product of pentaerythritol triacrylate, pentaerythritol trimethacrylate and the like with a dibasic acid anhydride. The ethylenically unsaturated monomer is 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, a linear or branched aliphatic or alicyclic group (however, however). It may further contain an ethylenically unsaturated compound having no carboxyl group, such as a (meth) acrylic acid ester (which may have a partially unsaturated bond in the ring).

The carboxyl group-containing resin (F) may contain a compound having a carboxyl group and an ethylenically unsaturated group (hereinafter, referred to as a component (F2)). The component (F2) is, for example, an intermediate which is a reaction product of an epoxy compound (g1) having two or more epoxy groups in one molecule and an ethylenically unsaturated compound (g2), a polyvalent carboxylic acid and its anhydride. It contains a resin (referred to as the first resin (g)) which is a reaction product with at least one compound (g3) selected from the group of substances. In the first resin (g), for example, the compound (g3) is added to an intermediate obtained by reacting an epoxy group in an epoxy compound (g1) with a carboxyl group in an ethylenically unsaturated compound (g2). You can get it. The epoxy compound (g1) can contain an appropriate epoxy resin such as a cresol novolac type epoxy resin and a phenol novolac type epoxy resin. The epoxy compound (g1) may contain a polymer of the ethylenically unsaturated compound (h). The ethylenically unsaturated compound (h) contains a compound (h1) having an epoxy group such as glycidyl (meth) acrylate, or further has no epoxy group such as 2- (meth) acryloyloxyethyl phthalate. Contains compound (h2). The ethylenically unsaturated compound (g2) preferably contains at least one of acrylic acid and methacrylic acid. The compound (g3) contains one or more compounds selected from the group consisting of polyvalent carboxylic acids such as phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid and anhydrides of these polyvalent carboxylic acids. ..

The component (F2) is a resin (second resin) which is a reaction product of a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group and an ethylenically unsaturated compound having an epoxy group. (I)) may be contained. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group. The second resin (i) is obtained by reacting an ethylenically unsaturated compound having an epoxy group with a part of the carboxyl groups in the polymer. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group. The ethylenically unsaturated compound having a carboxyl group contains, for example, a compound such as acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≈2) monoacrylate, pentaerythritol triacrylate, and pentaerythritol trimethacrylate. Ethyl unsaturated compounds having no carboxyl group include, for example, 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, linear or branched aliphatic or fat. It contains a compound such as a cyclic (meth) acrylic acid ester, which may have a partially unsaturated bond in the ring. The ethylenically unsaturated compound having an epoxy group preferably contains glycidyl (meth) acrylate.

The carboxyl group-containing resin (A) includes only the carboxyl group-containing resin (A1), or the carboxyl group-containing resin (A1) and the carboxyl group-containing resin (F). In the present embodiment, the carboxyl group-containing resin (A) preferably contains the carboxyl group-containing resin (A1) in an amount of 30% by mass or more, more preferably 50% by mass or more, and preferably 100% by mass. More preferred. In this case, the heat resistance and insulation reliability of the cured product of the photosensitive resin composition can be particularly improved. In addition, the tackiness of the film formed from the photosensitive resin composition can be sufficiently suppressed. Further, the developability of the photosensitive resin composition with an alkaline aqueous solution can be ensured.

In the present embodiment, the weight average molecular weight of the carboxyl group-containing resin (A1) is preferably in the range of 1000 to 5000. When the weight average molecular weight of the carboxyl group-containing resin (A1) is 1000 or more, the tackiness of the film formed from the photosensitive resin composition is further suppressed, and the insulation reliability of the cured product of the photosensitive resin composition is further suppressed. And the plating resistance can be further improved. Further, when the weight average molecular weight of the carboxyl group-containing resin (A1) is 5000 or less, the developability of the photosensitive resin composition with an alkaline aqueous solution is particularly improved. The weight average molecular weight of the carboxyl group-containing resin (A1) can be calculated, for example, from the measurement results under the following conditions by gel permeation chromatography.

GPC device: Showa Denko SHODEX SYSTEM 11,
Column: 4 series of SHODEX KF-800P, KF-005, KF-003, KF-001,
Mobile phase: THF,
Flow rate: 1 ml / min,
Column temperature: 45 ° C,
Detector: RI,
Conversion: Polystyrene.

In the present embodiment, the solid acid value of the carboxyl group-containing resin (A1) in the photosensitive resin composition is preferably in the range of 60 to 140 mgKOH / g. In this case, the developability of the photosensitive resin composition is particularly improved. It is more preferable if the acid value is in the range of 80 to 135 mgKOH / g, and further preferably if the acid value is in the range of 90 to 130 mgKOH / g.

The photosensitive resin composition of the present embodiment contains an unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule, and a photopolymerization initiator (in addition to the above-mentioned carboxyl group-containing resin (A)). It contains C) and an epoxy compound (D).

The unsaturated compound (B) can impart photocurability to the photosensitive resin composition. The unsaturated compound (B) is a monofunctional (meth) acrylate such as 2-hydroxyethyl (meth) acrylate; as well as a diethylene glycol di (meth) acrylate, a trimethylol propandi (meth) acrylate, and a trimethyl propanthry (meth). Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ε-caprolactone-modified pentaeristol hexaacrylate, tricyclodecandy It can contain at least one compound selected from the group consisting of polyfunctional (meth) acrylates such as methanol di (meth) acrylate.

In particular, the unsaturated compound (B) preferably contains a trifunctional compound, that is, a compound having three unsaturated bonds in one molecule. In this case, the resolvability when the film formed from the photosensitive resin composition is exposed and developed is improved, and the developability of the photosensitive resin composition with an alkaline aqueous solution is particularly improved. Trifunctional compounds include, for example, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, pentaeristoltri (meth) acrylate, ethoxylated isocyanurate tri (meth) acrylate and ε-caprolactone-modified. It can contain at least one compound selected from the group consisting of tris- (2-acryloxyethyl) isocyanurate and ethoxylated glycerin tri (meth) acrylate.

It is also preferable that the unsaturated compound (B) contains a phosphorus-containing compound (phosphorus-containing unsaturated compound). In this case, the flame retardancy of the cured product of the photosensitive resin composition is improved. Examples of the phosphorus-containing unsaturated compound include 2-methacryloyloxyethyl acid phosphate (specific examples, product numbers Light Ester P-1M and Light Ester P-2M manufactured by Kyoeisha Chemical Co., Ltd.) and 2-acryloyloxyethyl acid phosphate. (Specific example, product number light acrylate P-1A manufactured by Kyoeisha Chemical Co., Ltd.), diphenyl-2-methacryloyloxyethyl phosphate (part number MR-260 manufactured by Daihachi Kogyo Co., Ltd.), and Showa Polymer Co., Ltd. HFA series (for example, product number HFA-6003, which is an addition reaction product of dipentaerystol hexaacrylate and HCA, and HFA-6007, an addition reaction product of caprolactone-modified dipentaerystol hexaacrylate and HCA. It can contain one or more compounds selected from the group consisting of product numbers HFA-303, HFA-6127, etc.).

The unsaturated compound (B) may contain a prepolymer. The prepolymer is at least one selected from the group consisting of, for example, a prepolymer obtained by polymerizing a monomer having an ethylenically unsaturated bond and then adding an ethylenically unsaturated group, and oligo (meth) acrylate prepolymers. Can contain the compounds of. Oligo (meth) acrylate prepolymers include, for example, epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate, alkyd resin (meth) acrylate, silicone resin (meth) acrylate, and spirane resin (meth) acrylate. It can contain at least one component selected from the group consisting of.

The photopolymerization initiator (C) contains, for example, an acylphosphine oxide-based photopolymerization initiator (C1). That is, the photosensitive resin composition contains, for example, an acylphosphine oxide-based photopolymerization initiator (C1). In this case, even though the photosensitive resin composition contains the carboxyl group-containing resin (A1), high photosensitive can be imparted to the photosensitive resin composition when the photosensitive resin composition is exposed to ultraviolet rays. In addition, the occurrence of ion migration in the layer containing the cured product of the photosensitive resin composition is suppressed, and the insulation reliability of the layer containing the cured product is further improved.

The acylphosphine oxide-based photopolymerization initiator (C1) is a monoacyl such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide or 2,4,6-trimethylbenzoyl-ethyl-phenyl-phosphinate. Phosphine oxide-based photopolymerization initiator, and bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2) , 6-Dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,4,6) -Trimethylbenzoyl) Selected from the group consisting of bisacylphosphine oxide-based photopolymerization initiators such as phenylphosphine oxide and (2,5,6-trimethylbenzoyl) -2,4,4-trimethylpentylphosphine oxide. It can contain one or more components. In particular, the acylphosphine oxide-based photopolymerization initiator (C1) preferably contains 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and the acylphosphine oxide-based photopolymerization initiator (C1) contains 2, It is also preferable to contain only 4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

It is preferable that the photopolymerization initiator (C) contains a hydroxyketone-based photopolymerization initiator (C2) in addition to the acylphosphine oxide-based photopolymerization initiator (C1). That is, it is preferable that the photosensitive resin composition contains a hydroxyketone-based photopolymerization initiator (C2). In this case, higher photosensitivity can be imparted to the photosensitive resin composition as compared with the case where the hydroxyketone-based photopolymerization initiator (C2) is not contained. As a result, when the coating film formed from the photosensitive resin composition is cured by irradiating it with ultraviolet rays, the coating film can be sufficiently cured from the surface to the deep part. Examples of the hydroxyketone-based photopolymerization initiator (C2) include 1-hydroxy-cyclohexyl-phenyl-ketone, phenylglycoxyacid methyl ester, and 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy. -2-Methyl-1-propane-1-one, 2-hydroxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1- On and 2-hydroxy-2-methyl-1-phenyl-propane-1-one can be mentioned.

The mass ratio of the acylphosphine oxide-based photopolymerization initiator (C1) to the hydroxyketone-based photopolymerization initiator (C2) is preferably in the range of 1: 0.01 to 1:10. In this case, the curability near the surface of the coating film formed from the photosensitive resin composition and the curability in the deep part can be improved in a well-balanced manner.

It is also preferable that the photopolymerization initiator (C) contains bis (diethylamino) benzophenone (C3). That is, the photosensitive resin composition contains an acylphosphine oxide-based photopolymerization initiator (C1) and a bis (diethylamino) benzophenone (C3), or an acylphosphine oxide-based photopolymerization initiator (C1), a hydroxyketone-based. It is also preferable to contain a photopolymerization initiator (C2) and a bis (diethylamino) benzophenone (C3). In this case, when the coating film formed from the photosensitive resin composition is partially exposed and then developed, the curing of the unexposed portion is suppressed, so that the resolution is particularly high. Therefore, it is possible to form a very fine pattern with the cured product of the photosensitive resin composition. In particular, when an interlayer insulating layer of a multilayer printed wiring board is prepared from a photosensitive resin composition and a small-diameter hole for a through hole is provided in the interlayer insulating layer by a photolithography method (see FIG. 1), the small-diameter hole is formed. It can be formed precisely and easily.

The bis (diethylamino) benzophenone (C3) is preferably in the range of 0.5 to 20% by mass with respect to the acylphosphine oxide-based photopolymerization initiator (C1). When the bis (diethylamino) benzophenone (C3) is 0.5% by mass or more, the resolution is particularly high. Further, when the bis (diethylamino) benzophenone (C3) is 20% by mass or less, the bis (diethylamino) benzophenone (C3) is less likely to inhibit the electrical insulating property of the cured product of the photosensitive resin composition.

The photosensitive resin composition may further contain a known photopolymerization accelerator, sensitizer and the like. For example, the photosensitive resin composition includes benzoin and its alkyl ethers; acetophenones such as acetophenone and benzyl dimethyl ketal; anthraquinones such as 2-methylanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2- Thioxanthones such as isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diisopropylthioxanthone; benzophenones such as benzophenone, 4-benzoyl-4'-methyldiphenylsulfide; xanthones such as 2,4-diisopropylxanthone; and 2- Α-Hydroxyketones such as hydroxy-2-methyl-1-phenyl-propan-1-one; nitrogen atoms such as 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone The component can contain at least one selected from the group consisting of the containing compounds. The photosensitive resin composition, together with the photopolymerization initiator (C), is known as a tertiary amine type such as p-dimethylbenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester, 2-dimethylaminoethylbenzoate and the like. It may contain a photopolymerization accelerator, a sensitizer, and the like. The photosensitive resin composition may contain at least one of a photopolymerization initiator for visible light exposure and a photopolymerization initiator for near-infrared exposure, if necessary. The photosensitive resin composition contains a photopolymerization initiator (C), a coumarin derivative such as 7-diethylamino-4-methylcoumarin, which is a sensitizer for a laser exposure method, a carbocyanine dye system, a xanthene dye system, and the like. You may.

The epoxy compound (D) can impart thermosetting property to the photosensitive resin composition. The epoxy compound (D) preferably has at least two epoxy groups in one molecule. The epoxy compound (D) may be a solvent-insoluble epoxy compound or a general-purpose solvent-soluble epoxy compound. The epoxy compound (D) is a phenol novolac type epoxy resin (specific example, product number EPICLON N-775 manufactured by DIC Co., Ltd.), cresol novolac type epoxy resin (specific example, product number EPICLON N-695 manufactured by DIC Co., Ltd.), bisphenol A. Novolak type epoxy resin (specific example, product number EPICLON N-865 manufactured by DIC Co., Ltd.), bisphenol A type epoxy resin (specific example, product number jER1001 manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resin (specific example, Mitsubishi Chemical) Part number jER4004P manufactured by Co., Ltd.), bisphenol S type epoxy resin (specific example, product number EPICLON EXA-1514 manufactured by DIC Co., Ltd.), bisphenol AD type epoxy resin, biphenyl type epoxy resin (specific example, product number manufactured by Mitsubishi Chemical Co., Ltd.) YX4000), biphenyl novolac type epoxy resin (specific example, product number NC-3000 manufactured by Nippon Kayaku Co., Ltd.), hydrogenated bisphenol A type epoxy resin (specific example, product number ST-4000D manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), naphthalene. Type epoxy resin (specific example, product number EPICLON HP-4032, EPICLON HP-4700, EPICLON HP-4770 manufactured by DIC Co., Ltd.), hydroquinone type epoxy resin (specific example, product number YDC-1312 manufactured by Nippon Steel & Sumitomo Metal Corporation), Tasha Lee butyl catechol type epoxy resin (specific example, product number EPICLON HP-820 manufactured by DIC Co., Ltd.), dicyclopentadiene type epoxy resin (specific example, product number EPICLON HP-7200 manufactured by DIC), adamantan type epoxy resin (specific example). Idemitsu Kosan Co., Ltd. product number ADAMANTATE X-E-201), bisphenol type epoxy resin (specific example, Nippon Steel & Sumikin Chemical Co., Ltd. product number YSLV-80XY), biphenyl ether type epoxy resin (specific example, Nippon Steel & Sumikin Chemical Co., Ltd.) Product number YSLV-80DE), epoxy resin with a bisphenol fluorene skeleton (specific example, epoxy resin with the structure shown in formula (7)), rubber-like core-shell polymer-modified bisphenol A type epoxy resin (specific example, product number manufactured by Kaneka Co., Ltd.) MX-156), rubber-like core-shell polymer-modified bisphenol F-type epoxy resin (specific example, product number MX-136 manufactured by Kaneka Co., Ltd.), and special officials Noh type epoxy resin (for example, part numbers YL7175-500 and YL7175-1000 manufactured by Mitsubishi Chemical Corporation; part numbers EPICLON TSR-960, EPICLON TER-601, EPICLON TSR-250-80BX, EPICLON 1650 manufactured by DIC Corporation. Contains one or more components selected from the group consisting of -75MPX, EPICLON EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLON EXA-9726; part number YSLV-120TE manufactured by Nippon Steel & Sumikin Chemical Corporation). Is preferable.

In this embodiment, the epoxy compound (D) contains a crystalline epoxy resin. The crystalline epoxy resin is an epoxy resin having a melting point. Therefore, the developability of the photosensitive resin composition with an alkaline aqueous solution can be improved, and the photosensitive resin composition can be developed with an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide. it can. This crystalline epoxy resin is, for example, 1,3,5-tris (2,3-epoxypropyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) trione, hydroquinone type crystal. Sex epoxy resin (specific example, product name YDC-1312 manufactured by Nippon Steel & Sumitomo Metal Corporation), biphenyl type crystalline epoxy resin (specific example, product number YX-4000 manufactured by Mitsubishi Chemical Corporation), diphenyl ether type crystalline epoxy resin (specific) For example, product number YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), bisphenol type crystalline epoxy resin (specific example, product number YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), tetrakisphenol ethane type crystalline epoxy resin (as a specific example). It can contain at least one component selected from the group consisting of product number GTR-1800 manufactured by Nippon Kayaku Co., Ltd.) and a bisphenol fluorene type crystalline epoxy resin (as a specific example, an epoxy resin having a structure represented by the formula (7)). ..

Further, in the present embodiment, it is preferable that the crystalline epoxy resin does not contain N atoms. When the crystalline epoxy resin contains N atoms, the N atoms easily attract ions electrically, so that migration can occur in a printed wiring board provided with an interlayer insulating layer or a solder resist layer containing a cured product of the photosensitive resin composition. It is more likely to occur and electrical reliability can be reduced. Therefore, since the crystalline epoxy resin does not contain N atoms, the occurrence of migration of the printed wiring board can be suppressed, and the electrical reliability of the printed wiring board can be ensured. Crystalline epoxy resins containing N atoms include, for example, 1,3,5-tris (2,3-epoxypropyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) trions. And so on.

The epoxy compound (D) may contain a phosphorus-containing epoxy resin. In this case, the flame retardancy of the cured product of the photosensitive resin composition is improved. Phosphorus-containing epoxy resins include phosphoric acid-modified bisphenol F-type epoxy resins (specific examples, product numbers EPICLON EXA-9726 and EPICLON EXA-9710 manufactured by DIC Corporation), product numbers Epototo FX-305 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., etc. Can be mentioned.

The photosensitive resin composition may contain melamine (E). In this case, the adhesion between the cured product of the photosensitive resin composition and the metal such as copper is increased. Therefore, the photosensitive resin composition is particularly suitable as an insulating material for printed wiring boards. Further, the plating resistance of the cured product of the photosensitive resin composition, that is, the whitening resistance during the electroless nickel / gold plating treatment is improved.

The photosensitive resin composition may contain an organic solvent. The organic solvent is used for the purpose of liquefaction or varnishing of the photosensitive resin composition, adjusting the viscosity, adjusting the coatability, adjusting the film-forming property, and the like.

Organic solvents include linear, branched, secondary or polyhydric alcohols such as ethanol, propyl alcohol, isopropyl alcohol, hexanol and ethylene glycol; ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene. Classes: Petroleum-based aromatic mixed solvents such as Swazol series (manufactured by Maruzen Petrochemical Co., Ltd.) and Solbesso series (manufactured by Exxon Chemical Co., Ltd.); Cellosolves such as cellosolve and butylcellosolve; Calvi such as carbitol and butylcarbitol. Thor; propylene glycol alkyl ethers such as propylene glycol methyl ether; polypropylene glycol alkyl ethers such as dipropylene glycol methyl ether; acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, carbitol acetate; and dialkyl glycol ethers. It can contain one or more compounds selected from the group consisting of classes.

The carboxyl group-containing resin (A) is preferably in the range of 5 to 85% by mass, more preferably in the range of 10 to 75% by mass, and more preferably 30 to 60% with respect to the solid content of the photosensitive resin composition. It is more preferable if it is within the range of mass%.

As described above, the unsaturated compound (B) is in the range of 21 to 40% by mass with respect to the carboxyl group-containing resin (A). The unsaturated compound (B) is more preferably in the range of 23 to 36% by mass with respect to the carboxyl group-containing resin (A).

The photopolymerization initiator (C) is preferably in the range of 0.1 to 30% by mass, more preferably in the range of 1 to 25% by mass with respect to the carboxyl group-containing resin (A).

Regarding the amount of the epoxy compound (D), the total equivalent of the epoxy groups contained in the epoxy compound (D) is 0.7 to 2.5 with respect to one equivalent of the carboxyl groups contained in the carboxyl group-containing resin (A). It is preferably in the range of 0.7 to 2.3, more preferably in the range of 0.7 to 2.0, and even more preferably in the range of 0.7 to 2.0. Further, the crystalline epoxy resin is preferably in the range of 10 to 100% by mass, more preferably in the range of 30 to 100% by mass, and 35 to 100% by mass with respect to the epoxy compound (D). It is more preferable that it is within the range of. In this case, the thermosetting reactivity of the carboxyl group-containing resin and the epoxy resin is suppressed in the steps before the thermosetting of the photosensitive resin composition, and the developability can be improved.

When the photosensitive resin composition contains melamine (E), the melamine (E) is preferably in the range of 0.1 to 10% by mass with respect to the carboxyl group-containing resin (A), and is 0.5 to 10% by mass. It is more preferable if it is within the range of 5% by mass.

When the photosensitive resin composition contains an organic solvent, the amount of the organic solvent is such that the organic solvent volatilizes quickly when the coating film formed from the photosensitive resin composition is dried, that is, the organic solvent is dried. It is preferable to adjust so that it does not remain on the film. In particular, the organic solvent is preferably in the range of 0 to 99.5% by mass, and more preferably in the range of 15 to 60% by mass with respect to the entire photosensitive resin composition. Since the preferable ratio of the organic solvent differs depending on the coating method and the like, it is preferable that the ratio is appropriately adjusted according to the coating method.

The solid content is the total amount of all the components excluding the volatile components such as the solvent from the photosensitive resin composition.

The photosensitive resin composition may further contain components other than the above components as long as the gist of the present invention is not deviated.

For example, the photosensitive resin composition may contain an inorganic filler. In this case, the curing shrinkage of the film formed from the photosensitive resin composition is reduced. The inorganic filler can contain, for example, one or more materials selected from the group consisting of barium sulfate, crystalline silica, nanosilica, carbon nanotubes, talc, bentonite, aluminum hydroxide, magnesium hydroxide, and titanium oxide. The photosensitive resin composition and its cured product may be whitened by containing a white material such as titanium oxide or zinc oxide in the inorganic filler. The proportion of the inorganic filler in the photosensitive resin composition is appropriately set, but is preferably in the range of 0 to 300% by mass with respect to the carboxyl group-containing resin (A).

The photosensitive resin composition is a tolylene diisocyanate-based, morpholini diisocyanate-based, isophorone diisocyanate-based and hexamethylene diisocyanate-based blocked isocyanate blocked with caprolactam, oxime, malonic acid ester or the like; melamine resin, n-butylated melamine resin. , Isobutylated melamine resin, butylated urea resin, butylated melamine urea cocondensate resin, benzoguanamine-based cocondensate resin and other amino resins; various thermocurable resins other than the above; ultraviolet curable epoxy (meth) acrylate; bisphenol A type , Phenol novolak type, cresol novolak type, alicyclic type and other epoxy resins with (meth) acrylic acid added; and diallyl phthalate resin, phenoxy resin, urethane resin, fluororesin and other polymer compounds. It may contain one or more resins selected from the group.

The photosensitive resin composition may contain a curing agent for curing the epoxy compound (D). The curing agent is, for example, imidazole, 2-methylimidazole, 2-ethyl imidazole, 2-ethyl-4-methyl imidazole, 2-phenyl imidazole, 4-phenyl imidazole, 1-cyanoethyl-2-phenyl imidazole, 1- (2). -Imidazole derivatives such as -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, Amine compounds such as 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic acid hydrazide and sevacinate hydrazide; phosphorus compounds such as triphenylphosphine; acid anhydrides; phenols; mercaptans; amine amine complexes; And one or more components selected from the group consisting of onium salts. Examples of commercially available products of these components are 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both are trade names of imidazole compounds) manufactured by Shikoku Kasei Co., Ltd., and U-CAT3503N, U manufactured by San Apro Co., Ltd. Examples thereof include -CAT3502T (trade name of a blocked isocyanate compound of dimethylamine), DBU, DBN, U-CATSA102, and U-CAT5002 (all of which are bicyclic amidine compounds and salts thereof).

The photosensitive resin composition may contain an adhesion-imparting agent other than melamine (E). Adhesion-imparting agents include, for example, guanamine, acetoguanamine, benzoguanamine, and 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2-vinyl-. Examples thereof include S-triazine derivatives such as 4,6-diamino-S-triazine / isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct.

The photosensitive resin composition is a curing accelerator; a colorant; a copolymer such as silicone or acrylate; a leveling agent; an adhesion imparting agent such as a silane coupling agent; a thixotropy agent; a polymerization inhibitor; an antihalation agent; a flame retardant. It may contain one or more components selected from the group consisting of antifoaming agents; antioxidants; surfactants; and polymer dispersants.

The content of the amine compound in the photosensitive resin composition is preferably as low as possible. In this case, the electrical insulation of the layer made of the cured product of the photosensitive resin composition is not easily impaired. In particular, the amine compound is preferably 6% by mass or less, more preferably 4% by mass or less, based on the carboxyl group-containing resin (A).

The photosensitive resin composition of the present embodiment includes a carboxyl group-containing resin (A) containing a carboxyl group-containing resin (A1), an unsaturated compound (B), a photopolymerization initiator (C), and an epoxy compound ( Manufactured by mixing with D).

Specifically, the photosensitive resin composition is prepared by blending the raw materials of the photosensitive resin composition as described above and kneading them by a known kneading method using, for example, a three-roll, a ball mill, a sand mill, or the like. obtain. When the raw material of the photosensitive resin composition contains a liquid component, a low-viscosity component, etc., the portion of the raw material excluding the liquid component, the low-viscosity component, etc. is first kneaded, and the resulting mixture is added. A photosensitive resin composition may be prepared by adding a liquid component, a component having a low viscosity, or the like and mixing them.

In consideration of storage stability and the like, a first agent may be prepared by mixing a part of the components of the photosensitive resin composition, and a second agent may be prepared by mixing the rest of the components. That is, the photosensitive resin composition may include a first agent and a second agent. In this case, for example, the first agent is prepared by previously mixing and dispersing the unsaturated compound (B), a part of the organic solvent, and the thermosetting component among the components of the photosensitive resin composition, and the photosensitive resin. The second agent may be prepared by mixing and dispersing the rest of the components of the composition. In this case, a required amount of the first agent and the second agent can be mixed in a timely manner to prepare a mixed solution, and the mixed solution can be cured to obtain a cured product.

The photosensitive resin composition according to this embodiment is suitable as an electrically insulating material for a printed wiring board. In particular, the photosensitive resin composition is suitable for forming an electrically insulating layer such as a solder resist layer, a plating resist layer, an etching resist layer, and an interlayer insulating layer.

When the photosensitive resin composition is formed into a film having a thickness of 25 μm, it is preferable that the film can be developed with an aqueous sodium carbonate solution. In this case, since it is possible to prepare an electrically insulating layer having a sufficiently large thickness from the photosensitive resin composition by a photolithography method, the photosensitive resin composition can be obtained from the interlayer insulating layer and the solder in the printed wiring board. It can be widely applied to prepare a resist layer or the like. Of course, it is also possible to prepare an electrically insulating layer having a thickness of less than 25 μm from the photosensitive resin composition.

It can be confirmed by the following method that the film can be developed with an aqueous sodium carbonate solution. A wet coating film is formed by applying the photosensitive resin composition on a suitable substrate, and the wet coating film is heated at 80 ° C. for 40 minutes to form a film having a thickness of 25 μm. A negative mask having an exposed portion that transmits ultraviolet rays and a non-exposed portion that shields ultraviolet rays is directly applied to the film, and the film is irradiated with ultraviolet rays under the condition of 500 mJ / cm ² through the negative mask. A 1% Na ₂ CO ₃ aqueous solution at 30 ° C. is injected onto the exposed film at an injection pressure of 0.2 MPa for 90 seconds, and then pure water is injected at an injection pressure of 0.2 MPa for 90 seconds. As a result of observing the film after this treatment, it can be determined that development is possible when the portion of the film corresponding to the non-exposed portion is removed and no residue is observed.

Hereinafter, an example of a method for manufacturing a printed wiring board provided with an interlayer insulating layer formed from the photosensitive resin composition according to the present embodiment will be described with reference to FIGS. 1A to 1E. In this method, through holes are formed in the interlayer insulating layer by a photolithography method.

First, the core material 1 is prepared as shown in FIG. 1A. The core material 1 includes, for example, at least one insulating layer 2 and at least one conductor wiring 3. The conductor wiring 3 provided on one surface of the core material 1 is hereinafter referred to as the first conductor wiring 3. As shown in FIG. 1B, a film 4 is formed from the photosensitive resin composition on the surface of the core material 1 on which the first conductor wiring 3 is provided. Examples of the method for forming the film 4 include a coating method and a dry film method.

In the coating method, for example, the photosensitive resin composition is coated on the core material 1 to form a wet coating film. The method for applying the photosensitive resin composition is selected from the group consisting of known methods such as a dipping method, a spray method, a spin coating method, a roll coating method, a curtain coating method, and a screen printing method. Subsequently, in order to volatilize the organic solvent in the photosensitive resin composition, the wet coating film can be dried at a temperature in the range of, for example, 60 to 120 ° C. to obtain the film 4.

In the dry film method, a dry film containing the photosensitive resin composition is formed on the support by first applying the photosensitive resin composition on an appropriate support made of polyester or the like and then drying the support. As a result, a dry film with a support including a dry film and a support for supporting the dry film can be obtained. The dry film in the dry film with a support is superposed on the core material 1, pressure is applied to the dry film and the core material 1, and then the support is peeled off from the dry film, whereby the dry film is cored from above the support. Transfer onto material 1. As a result, a film 4 made of a dry film is provided on the core material 1.

By exposing the film 4, it is partially photocured as shown in FIG. 1C. Therefore, for example, after applying a negative mask to the film 4, the film 4 is irradiated with ultraviolet rays via the negative mask. The negative mask includes an exposed portion that transmits ultraviolet rays and a non-exposed portion that shields ultraviolet rays, and the non-exposed portion is provided at a position that matches the position of the through hole 10. The negative mask is, for example, a photo tool such as a mask film or a dry plate. The ultraviolet light source is selected from the group consisting of, for example, a chemical lamp, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp and a metal halide lamp.

As the exposure method, a method other than the method using a negative mask may be adopted. For example, the film may be exposed by a direct drawing method in which ultraviolet rays emitted from a light source are applied only to a portion of the film 4 to be exposed. Light sources applied to the direct drawing method include, for example, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, g-line (436 nm), h-line (405 nm), i-line (365 nm), and g-line, h-line, and i-line. It is selected from a group consisting of two or more combinations of.

Further, in the dry film method, after the dry film in the dry film with a support is laminated on the core material 1, the support is transmitted through the support and the film 4 made of the dry film is irradiated with ultraviolet rays without peeling the support. The film 4 may be exposed with, and then the support may be peeled off from the film 4 before the development process.

Subsequently, the film 4 is subjected to a developing process to remove the unexposed portion 5 of the film 4 shown in FIG. 1C, whereby the hole 6 is formed at a position where the through hole 10 is formed as shown in FIG. 1D. Is provided. In the developing process, an appropriate developing solution can be used according to the composition of the photosensitive resin composition. The developer is, for example, an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide, or an organic amine. More specifically, the alkaline aqueous solution includes, for example, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, ammonium hydrogencarbonate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide and water. It contains at least one component selected from the group consisting of lithium oxide. The solvent in the alkaline aqueous solution may be water alone or a mixture of water and a hydrophilic organic solvent such as lower alcohols. The organic amine contains, for example, at least one component selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine.

The developing solution is preferably an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide, and particularly preferably a sodium carbonate aqueous solution. In this case, it is possible to improve the working environment and reduce the burden of waste treatment.

Subsequently, the film 4 is thermoset by heating. The heating conditions are, for example, a heating temperature in the range of 120 to 200 ° C. and a heating time in the range of 30 to 120 minutes. When the film 4 is thermoset in this way, the performance such as strength, hardness, and chemical resistance of the interlayer insulating layer 7 is improved.

If necessary, the film 4 may be further irradiated with ultraviolet rays before or after heating. In this case, the photocuring of the film 4 can be further advanced.

As described above, the interlayer insulating layer 7 made of a cured product of the photosensitive resin composition is provided on the core material 1. The second conductor wiring 8 and the hole plating 9 can be provided on the interlayer insulating layer 7 by a known method such as an additive method. As a result, as shown in FIG. 1E, the first conductor wiring 3, the second conductor wiring 8, the interlayer insulating layer 7 interposed between the first conductor wiring 3 and the second conductor wiring 8, and the second conductor wiring 8. A printed wiring board 11 having a through hole 10 for electrically connecting the first conductor wiring 3 and the second conductor wiring 8 can be obtained. In FIG. 1E, the hole plating 9 has a tubular shape that covers the inner surface of the hole 6, but the hole plating 9 may be filled in the entire inside of the hole 6.

An example of a method for manufacturing a printed wiring board provided with a solder resist layer formed from the photosensitive resin composition according to the present embodiment will be described.

First, prepare the core material. The core material includes, for example, at least one insulating layer and at least one conductor wiring. A film is formed from the photosensitive resin composition on the surface of the core material on which the conductor wiring is provided. Examples of the film forming method include a coating method and a dry film method. As the coating method and the dry film method, the same method as in the case of forming the above-mentioned interlayer insulating layer can be adopted. Partially photocured by exposing the film. As the exposure method, the same method as in the case of forming the interlayer insulating layer can be adopted. Subsequently, the film is developed to remove the unexposed portion of the film, whereby the exposed portion of the film remains on the core material. Subsequently, the film on the core material is thermoset by heating. As the developing method and the heating method, the same method as in the case of forming the interlayer insulating layer can be adopted. If necessary, the film may be further irradiated with ultraviolet light before or after heating. In this case, the photocuring of the film can be further advanced.

As described above, a solder resist layer made of a cured product of the photosensitive resin composition is provided on the core material. As a result, a printed wiring board including a core material having an insulating layer and a conductor wiring on the core material and a solder resist layer partially covering a surface of the core material on which the conductor wiring is provided can be obtained.

(1) Synthesis of carboxyl group-containing resin A carboxyl group-containing resin was synthesized by the following method.

(Synthesis Examples A-1 to A-10, Synthesis Example B-2)
In a four-necked flask equipped with a reflux condenser, a thermometer, an air blow tube and a stirrer, the components shown in the "First reaction" column in Table 1 are added, and these are stirred under air bubbling to form a mixture. Was prepared. The mixture was heated in a flask at the reaction temperature and reaction time shown in the "Reaction Conditions" column while stirring under air bubbling. This prepared a solution of the intermediate.

Subsequently, the components shown in the "second reaction" column of Table 1 were added to the solution of the intermediate in the flask, and the reaction temperature and reaction time shown in the "reaction conditions (1)" column were adjusted while stirring under air bubbling. It was heated. Subsequently, except for Synthesis Example B-2, the mixture was heated at the reaction temperature and reaction time shown in the “Reaction conditions (2)” column while stirring under air bubbling. As a result, a 65% by mass solution of the carboxyl group-containing resin was obtained. The weight average molecular weight and acid value of the carboxyl group-containing resin are as shown in Table 1.

The details of the components shown in column (a1) in Table 1 are as follows.
-Epoxy compound 1: A bisphenol fluorene-type epoxy compound having an epoxy equivalent of 250 g / eq, which is represented by the formula (7) and in which R _{1 to} R ₈ in the formula (7) are all hydrogen.
-Epoxy compound 2: Epoxy equivalent 279 g represented by the formula (7) in which R ₁ and R ₅ in the formula (7) are all methyl groups and R _{2 to} R ₄ and R _{6 to} R ₈ are all hydrogen. / eq bisphenol fluorene type epoxy compound.
-Epoxy compound 3: Cresol novolac type epoxy resin having an epoxy equivalent of 203 g / eq.

(Synthesis Example B-1)
48 parts by mass of methacrylic acid, ω-carboxy-polycaprolactone (n≈2) monoacrylate (Aronix M manufactured by Toa Synthetic Co., Ltd.) in a four-necked flask equipped with a reflux condenser, a thermometer, an air blow tube and a stirrer. -5300) 50 parts by mass, 92 parts by mass of methyl methacrylate, 10 parts by mass of styrene, 430 parts by mass of dipropylene glycol monomethyl ether, and 3.5 parts by mass of azobisisobutyronitrile were added. The solution in the four-necked flask was heated at 75 ° C. for 5 hours under a nitrogen stream to allow the polymerization reaction to proceed. As a result, a solution of the intermediate having a concentration of 32% was prepared.

Subsequently, 0.1 part by mass of hydroquinone, 64 parts by mass of glycidyl methacrylate, and 0.8 part by mass of dimethylbenzylamine were added to the solution of the intermediate in the flask and heated at 80 ° C. for 24 hours to proceed with the addition reaction. I let you. As a result, a 38% by mass solution of the carboxyl group-containing resin was obtained. The acid value of the carboxyl group-containing resin was 67 mgKOH / g.

(2) Preparation of Photosensitive Resin Composition The components shown in the table below were kneaded with three rolls and then stirred and mixed in a flask to obtain a photosensitive resin composition. The details of the components shown in the table are as follows.
-Unsaturated compound A: Trimethylolpropane triacrylate.
-Unsaturated compound B: trimethylolpropane trimethacrylate.
-Unsaturated compound C: Dipentaeristol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd., product number KAYARAD DPHA.
-Photopolymerization initiator A: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, manufactured by BASF, product number Irgacure TPO.
-Photopolymerization initiator B: 1-hydroxy-cyclohexyl-phenyl-ketone, manufactured by BASF, product number Irgacure 184.
-Photopolymerization initiator C: 4,4'-bis (diethylamino) benzophenone.
Crystalline epoxy resin A: 1,3,5-tris (2,3-epoxypropyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (high melting point type) , Melting point 150-158 ° C., epoxy equivalent 99 g / eq.
Crystalline epoxy resin B: Hydroquinone type crystalline epoxy resin, product number YDC-1312 manufactured by Nippon Steel Chemical Co., Ltd., melting point 138 to 145 ° C., epoxy equivalent 176 g / eq.
Crystalline epoxy resin C: Biphenyl type crystalline epoxy resin, product number YX-4000 manufactured by Mitsubishi Chemical Corporation, melting point 105 ° C., epoxy equivalent 187 g / eq.
Crystalline epoxy resin D: Diphenyl ether type crystalline epoxy resin, product number YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., melting point 80 to 90 ° C., epoxy equivalent 163 g / eq.
Crystalline epoxy resin E; bisphenol type crystalline epoxy resin, product number YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., melting point 75 to 85 ° C., epoxy equivalent 192 g / eq.
Acrystalline epoxy resin solution A: Acrystalline cresol novolac type epoxy resin, product number EPICLON N-695 manufactured by DIC Corporation, softening point 90 to 100 ° C., epoxy equivalent 214 g / eq with 70% solid content, diethylene glycol mono A solution dissolved in ethyl ether acetate.
-Amorphous epoxy resin solution B: Long-chain carbon chain-containing bisphenol A type epoxy resin, manufactured by DIC Corporation, product number EPICLON EXA-4816, liquid resin, epoxy equivalent 410 g / eq to diethylene glycol monoethyl acetate with 90% solid content Dissolved solution.
Aspherical epoxy resin C: rubber-like core-shell polymer-modified bisphenol A type epoxy resin, manufactured by Kaneka Co., Ltd., product number MX-120, liquid resin, epoxy equivalent 243 g / eq.
-Melamine: Fine powder melamine manufactured by Nissan Chemical Industries, Ltd.
-Antioxidant: Hindered phenolic antioxidant, manufactured by BASF, product number IRGANOX 1010.
-Blue pigment: Phthalocyanine blue.
-Yellow pigment: 1,1'-[(6-phenyl-1,3,5-triazine-2,4-diyl) bis (imino)] bis (9,10-anthracene dione).
-Barium sulfate: manufactured by Sakai Chemical Industry Co., Ltd., product number Variace B31.
-Talc: Made by Japan Talc, product number SG-2000.
-Bentonite: Made by Leox, product number Benton SD-2.
-Defoamer: manufactured by Shinetsu Silicone Co., Ltd., product number KS-66.
-Surfactant: Made by DIC, product number Megafuck F-477.
-Rheology control agent: manufactured by Big Chemie Japan Co., Ltd., product number BYK-430.
-Solvent A: Diethylene glycol monoethyl ether acetate.
-Solvent B: Methyl ethyl ketone.

(3) Preparation of Test Piece When the photosensitive resin compositions of Examples and Comparative Examples except Example 20 were used, a test piece was prepared as follows.

A glass epoxy copper-clad laminate (FR-4 type) provided with a copper foil having a thickness of 35 μm was prepared. A comb-shaped electrode having a line width / space width of 50 μm / 50 μm was formed as a conductor wiring on this glass epoxy copper-clad laminate by a subtractive method, thereby obtaining a core material. A wet coating film was formed by applying the photosensitive resin composition to the entire surface of the core material by a screen printing method. This wet coating film was heated at 80 ° C. for 40 minutes and pre-dried to form a film having a film thickness of 25 μm. A negative mask having a non-exposed portion having a pattern including a circular shape having a diameter of 50 μm was directly applied to the film, and the film was irradiated with ultraviolet rays under the condition of 500 mJ / cm ² through the negative mask. The film after exposure was developed. In the developing treatment, a 1% Na ₂ CO ₃ aqueous solution at 30 ° C. was injected onto the film at an injection pressure of 0.2 MPa for 90 seconds. Subsequently, the film was washed by injecting pure water at an injection pressure of 0.2 MPa for 90 seconds. As a result, the unexposed portion of the film was removed to form a hole. Subsequently, the film was irradiated with ultraviolet rays under the condition of 1000 mJ / cm ² , and then heated at 160 ° C. for 60 minutes. As a result, a layer made of a cured product of the photosensitive resin composition was formed on the core material. This gave a test piece.

When the photosensitive resin composition of Example 20 was used, a test piece was prepared as follows.

The photosensitive resin composition was applied to a film made of polyethylene terephthalate with an applicator and then dried by heating at 95 ° C. for 25 minutes to form a dry film having a thickness of 25 μm on the film.

A glass epoxy copper-clad laminate (FR-4 type) provided with a copper foil having a thickness of 35 μm was prepared. A comb-shaped electrode having a line width / space width of 50 μm / 50 μm was formed as a conductor wiring on this glass epoxy copper-clad laminate by a subtractive method, thereby obtaining a core material. A dry film was heat-laminated on the entire surface of the core material with a vacuum laminator, and then a polyethylene terephthalate film was peeled off from the dry film. The conditions for heat laminating are 0.5 MPa, 80 ° C., and 1 minute. As a result, a film having a film thickness of 25 μm made of a dry film was formed on the core material. This film was exposed, developed and irradiated with ultraviolet rays under the same conditions as in the above case. As a result, a layer made of a cured product of the photosensitive resin composition (which can be said to be a cured product of the dry film) was formed on the core material. This gave a test piece.

(4) Evaluation test (4-1) Tackiness For each of the Examples and Comparative Examples except Example 20, the degree of adhesiveness of the film when the negative mask was removed from the film after exposure of the film during the production of the test piece. It was evaluated as shown below.
A: No resistance is felt when removing the negative mask from the film, and no sticking marks are observed on the film after the negative mask is removed.
B: Resistance was felt when removing the negative mask from the film, and sticking marks were observed on the film after removing the negative mask.
C: It was difficult to remove the negative mask from the film, and when the negative mask was forcibly removed, the film was damaged.

In Comparative Examples 3, 6 and 8 in which the tackiness is evaluated as C, the evaluations of (4-3) to (4-7) are not performed.

(4-2) Developability For each of Examples and Comparative Examples except Example 20, a photosensitive resin composition was applied to the entire surface of one surface of a printed wiring board by a screen printing method to form a wet coating film. A film was formed by heating this wet coating film at 80 ° C. for 40 minutes or 60 minutes. This film was developed without exposure. In the developing treatment, a 1% Na ₂ CO ₃ aqueous solution at 30 ° C. was injected onto the film at an injection pressure of 0.2 MPa for 90 seconds, and then pure water was injected at an injection pressure of 0.2 MPa for 90 seconds. The printed wiring board after the treatment was observed, and the result was evaluated as follows.
A: The coating film is completely removed regardless of whether the heating time of the wet coating film is 40 minutes or 60 minutes.
B: When the heating time of the wet coating film was 40 minutes, all the film was removed, but in 60 minutes, a part of the film remained on the printed wiring board.
C: A part of the film remained on the printed wiring board regardless of whether the heating time of the wet coating film was 40 minutes or 60 minutes.

In Comparative Examples 1, 2, 4 and 5 in which the evaluation of developability is C, the following evaluations (4-3) to (4-7) are not performed.

(4-3) Resolution For each Example and Comparative Example, holes formed in the layer made of the cured product in the test piece were observed, and the results were evaluated as follows.
A: The diameter of the bottom of the hole is 40 μm or more.
B: The diameter of the bottom of the hole is 25 μm or more and less than 40 μm.
C: The diameter of the bottom of the hole is less than 25 μm, or a clear hole is not formed.

(4-4) Plating resistance A nickel plating layer is formed on the externally exposed portion of the conductor wiring of the test pieces of each Example and Comparative Example using a commercially available electroless nickel plating bath, and then commercially available. A gold-plated layer was formed using the electroless gold-plated bath of. As a result, a metal layer composed of a nickel-plated layer and a gold-plated layer was formed. The layer made of the cured product and the metal layer were visually observed. In addition, a cellophane adhesive tape peeling test was performed on the layer made of the cured product. The results were evaluated as follows.
A: No abnormality was observed in the appearance of the cured product layer and the metal layer, and the cured product layer was not peeled off by the cellophane adhesive tape peeling test.
B: Discoloration was observed in the layer made of the cured product, but the layer made of the cured product was not peeled off by the cellophane adhesive tape peeling test.
C: Lifting of the layer made of the cured product was observed, and the layer made of the cured product was peeled off by the cellophane adhesive tape peeling test.

(4-5) Line Insulation While applying a bias voltage of DC30V to the conductor wiring (comb electrode) in the test pieces of each example and comparative example, the test piece was heated at 121 ° C. and 97% R. H. Was exposed for 150 hours in the test environment of. The electrical resistance values between the comb-shaped electrodes of the cured product layer under this test environment were constantly measured, and the results were evaluated according to the following evaluation criteria.
A: Between the start of the study until after 150 hours, the electric resistance value was always maintained above 10 ⁶ Omega.
B: The electric resistance value until passage 100 hours from the start test is always maintained more than 10 ⁶ Omega, the electric resistance value is less than 10 ⁶ Omega for a period shorter 150 h from the time of start of the test.
C: electrical resistance was less than 10 ⁶ Omega before lapse of 100 hours from the start the test.

(4-6) Interlayer insulation A conductive tape was attached on the layer made of the cured product in the test pieces of each example and comparative example. While applying a bias voltage of DC100V to this conductive tape, the test piece was heated at 121 ° C. and 97% R. H. Was exposed for 60 hours under the test environment of. The electric resistance value between the conductor wiring of the layer made of the cured product and the conductive tape under this test environment was constantly measured, and the result was evaluated according to the following evaluation criteria.
A: Between the start of the study until after 60 hours, the electric resistance value was always maintained above 10 ⁶ Omega.
B: The electric resistance value from the start of the study until after 50 hours was always maintained above 10 ⁶ Omega, the electric resistance value is less than 10 ⁶ Omega before after 60 hours from the time of start of the test.
C: electrical resistance was less than 10 ⁶ Omega for a period shorter 50 hours from the time of start of the test.

(4-7) PCT
The test pieces of each Example and Comparative Example were heated at 121 ° C. and 100% R. H. After being left in the environment of 100 hours, the appearance of the layer made of the cured product was evaluated according to the following evaluation criteria.
A: No abnormality was found in the layer made of the cured product.
B: Discoloration was observed in the layer made of the cured product.
C: A large discoloration was observed in the layer made of the cured product, and some swelling occurred.

The results of the above evaluation tests are shown in Tables 2 to 5 below.

Claims (11)

Carboxylic acid group-containing resin (A) and
An unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule,
Photopolymerization initiator (C) and
Containing with epoxy compound (D),
The carboxyl group-containing resin (A) is represented by the following formula (1), and in the formula (1), R _{1 to} R ₈ are independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen, bisphenol fluorene. It contains an intermediate which is a reaction product of an epoxy compound (a1) having a skeleton, an unsaturated group-containing carboxylic acid (a2), and a carboxyl group-containing resin (A1) which is a reaction product of an acid anhydride. The content of the unsaturated compound (B) with respect to the carboxyl group-containing resin (A) is 21 to 40% by mass.
The epoxy compound (D) contains a crystalline epoxy resin.
Photosensitive resin composition.

The photosensitive resin composition according to claim 1, wherein the unsaturated compound (B) contains a compound having three unsaturated bonds in one molecule. The photosensitive resin composition according to any one of claims 1 or 2, wherein the acid anhydride contains an acid dianhydride. The photosensitive resin composition according to claim 3, wherein the acid dianhydride contains 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride. The photosensitive resin composition according to any one of claims 1 to 4, wherein the solid acid value of the carboxyl group-containing resin (A1) is in the range of 60 to 140 mgKOH / g. The photosensitive resin composition according to any one of claims 1 to 5, wherein the acid anhydride contains 1,2,3,6-tetrahydrophthalic anhydride. The photosensitive resin composition according to any one of claims 1 to 6, wherein the crystalline epoxy resin does not contain N atoms. A dry film containing the photosensitive resin composition according to any one of claims 1 to 7. A printed wiring board provided with an interlayer insulating layer containing a cured product of the photosensitive resin composition according to any one of claims 1 to 7. A printed wiring board comprising a solder resist layer containing a cured product of the photosensitive resin composition according to any one of claims 1 to 7. Represented by the following formula (1), in the formula (1), R _{1 to} R ₈ are independently hydrogen, an epoxy compound (a1) having a bisphenol fluorene skeleton which is an alkyl group having 1 to 5 carbon atoms or a halogen, and The unsaturated group-containing carboxylic acid (a2) was reacted, and the resulting intermediate was mixed with an acid anhydride containing at least one of an acid dianhydride (a3) and an acid monoanhydride (a4). By reacting, a carboxyl group-containing resin (A1) is synthesized.
The carboxyl group-containing resin (A) containing the carboxyl group-containing resin (A1) and
An unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule,
Photopolymerization initiator (C) and
Including mixing with epoxy compound (D)
The content of the unsaturated compound (B) with respect to the carboxyl group-containing resin (A) is 21 to 40% by mass.
The epoxy compound (D) contains a crystalline epoxy resin.
A method for producing a photosensitive resin composition.

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