Photosensitive resin composition, photosensitive element, cured product, method for producing cured product pattern, and method for producing conductor pattern

Abstract

A photosensitive resin composition contains a binder polymer, a photopolymerizable compound, and a photopolymerization initiator. The photopolymerizable compound contains a polyfunctional monomer having two or more radical reactive groups and 8‒16 oxyethylene groups. The polyfunctional monomer content is 90% or more by mass based on the total amount of the photopolymerizable compound, and the mass ratio of the binder polymer to the photopolymerizable compound is more than 0 and 1.35 or less. A photosensitive element 10 comprises a support 12 and a photosensitive layer 14 disposed on the support 12. The photosensitive layer 14 includes the photosensitive resin composition previously described.

Description

Photosensitive resin composition, photosensitive element, cured product, method for producing a cured product pattern, and method for producing a conductive pattern

[0001] The present disclosure relates to a photosensitive resin composition, a photosensitive element, a cured product, a method for producing a cured product pattern, a method for producing a conductor pattern, and the like.

[0002] In the manufacture of wiring boards and the like, a cured product pattern is formed as a resist pattern to obtain a desired conductor pattern (e.g., a wiring pattern). For example, the cured product pattern can be formed by forming a photosensitive layer (photosensitive resin layer) on a substrate using a photosensitive resin composition, and then exposing and developing the photosensitive layer. Various compositions have been investigated as photosensitive resin compositions. For example, Patent Document 1 below describes a photosensitive resin composition containing an anthracene derivative.

[0003] International Publication No. 2007 / 004619

[0004] When a cured product pattern is obtained on a substrate using a photosensitive resin composition, it is required that the cured product pattern has excellent conformability to the substrate without forming voids between the substrate and the cured product pattern. In particular, when a cured product pattern is obtained on a substrate having a recess using a photosensitive resin composition, voids are likely to form between the substrate and the cured product pattern. Therefore, it is required that the photosensitive resin composition obtain a cured product pattern that has excellent conformability to the substrate having a recess.

[0005] One aspect of the present disclosure is to provide a photosensitive resin composition that can provide a cured product pattern that has excellent conformability to a substrate having a recess. Another aspect of the present disclosure is to provide a photosensitive element using such a photosensitive resin composition. Another aspect of the present disclosure is to provide a cured product of the above-mentioned photosensitive resin composition. Another aspect of the present disclosure is to provide a method for producing a cured product pattern using the above-mentioned photosensitive resin composition. Another aspect of the present disclosure is to provide a method for producing a conductor pattern using such a method for producing a cured product pattern.

[0006] In some aspects, the present disclosure relates to the following [1] to

[13] , etc. [1] A photosensitive resin composition comprising a binder polymer, a photopolymerizable compound, and a photopolymerization initiator, wherein the photopolymerizable compound comprises a polyfunctional monomer having two or more radical reactive groups and 8 to 16 oxyethylene groups, the content of the polyfunctional monomer being 90% by mass or more based on the total amount of the photopolymerizable compound, and the mass ratio of the binder polymer to the photopolymerizable compound being greater than 0 and less than 1.35. [2] The photosensitive resin composition according to [1], wherein the content of the polyfunctional monomer is 96% by mass or more based on the total amount of the photopolymerizable compound. [3] The photosensitive resin composition according to [1] or [2], wherein the mass ratio of the binder polymer to the photopolymerizable compound is greater than 0 and less than 1.25. [4] The photosensitive resin composition according to any one of [1] to [3], wherein the molecular weight of the polyfunctional monomer is 600 to 1,200. [5] The photosensitive resin composition according to any one of [1] to [4], wherein the polyfunctional monomer further has a bisphenol A skeleton. [6] The photosensitive resin composition according to any one of [1] to [5], wherein the binder polymer has a styrene compound and an aryl (meth)acrylate as monomer units. [7] The photosensitive resin composition according to [6], wherein the binder polymer further has a hydroxyalkyl (meth)acrylate as a monomer unit. [8] The photosensitive resin composition according to any one of [1] to [7], further comprising a sensitizer. [9] The photosensitive resin composition according to [8], wherein the sensitizer comprises a dialkylaminobenzophenone compound.

[10] A photosensitive element comprising a support and a photosensitive layer disposed on the support, wherein the photosensitive layer comprises the photosensitive resin composition according to any one of [1] to [9].

[11] A cured product of the photosensitive resin composition according to any one of [1] to [9].

[12] A method for producing a cured product pattern, comprising: a step of forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of [1] to [9]; a step of photocuring a portion of the photosensitive layer; and a step of removing at least a portion of an uncured portion of the photosensitive layer to form a cured product pattern.

[13] A method for producing a conductor pattern, comprising a step of forming a conductor pattern using, as a mask, the cured product pattern obtained by the method for producing a cured product pattern according to

[12] .

[0007] According to one aspect of the present disclosure, it is possible to provide a photosensitive resin composition that can obtain a cured product pattern that has excellent conformability to a substrate having a recess. According to another aspect of the present disclosure, it is possible to provide a photosensitive element using such a photosensitive resin composition. According to another aspect of the present disclosure, it is possible to provide a cured product of the above-mentioned photosensitive resin composition. According to another aspect of the present disclosure, it is possible to provide a method for producing a cured product pattern using the above-mentioned photosensitive resin composition. According to another aspect of the present disclosure, it is possible to provide a method for producing a conductor pattern using such a method for producing a cured product pattern.

[0008] 1A and 1B are schematic cross-sectional views showing an example of a photosensitive element and an example of a method for manufacturing a conductor pattern.

[0009] Hereinafter, embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

[0010] In this specification, numerical ranges indicated using "to" indicate a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. A numerical range "A or greater" means a range exceeding A and A. A numerical range "A or less" means a range less than A and A. In numerical ranges described in stages in this specification, the upper or lower limit of a numerical range in a certain stage can be arbitrarily combined with the upper or lower limit of a numerical range in another stage. In numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. "A or B" may include either A or B, or may include both. Unless otherwise specified, the materials exemplified in this specification can be used alone or in combination of two or more. When multiple substances corresponding to each component are present in the composition, the content of each component in the composition refers to the total amount of the multiple substances present in the composition, unless otherwise specified. The term "layer" encompasses structures that are formed over the entire surface as well as structures that are formed only partially when observed in a plan view. The term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, as long as the process achieves its intended function. "(Meth)acrylate" refers to at least one of acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acrylic." The content of (meth)acrylic acid monomer units refers to the total amount of acrylic acid monomer units and methacrylic acid monomer units. The same applies to other similar contents, such as the content of alkyl (meth)acrylate monomer units. Unless otherwise specified, "alkyl groups" may be linear, branched, or cyclic. "Hydroxy groups" do not include OH groups contained in carboxy groups. The solid content of a photosensitive resin composition refers to the non-volatile content excluding volatile components (water, organic solvents, etc.) that can volatilize. In other words, the solid content refers to the components that remain without volatilization during drying of the photosensitive resin composition, including components that are liquid, syrup-like, waxy, etc. at room temperature (25°C). "EO-modified" means a compound having a (poly)oxyethylene group."(Poly)oxyethylene group" means an oxyethylene group or a polyoxyethylene group in which two or more ethylene groups are linked by ether bonds. "PO-modified" means a compound having a (poly)oxypropylene group. "(Poly)oxypropylene group" means an oxypropylene group or a polyoxypropylene group in which two or more propylene groups are linked by ether bonds.

[0011] The photosensitive resin composition according to the present embodiment contains (A) a binder polymer (hereinafter sometimes referred to as "component (A)"), (B) a photopolymerizable compound (hereinafter sometimes referred to as "component (B)"), and (C) a photopolymerization initiator (hereinafter sometimes referred to as "component (C)"). In the photosensitive resin composition according to the present embodiment, component (B) contains a polyfunctional monomer having two or more radical reactive groups and 8 to 16 oxyethylene groups (hereinafter sometimes referred to as "component (b)"), the content of component (b) is 90 mass% or more based on the total amount of component (B), and the mass ratio of component (A) to component (B) (content of component (A) / content of component (B)) is more than 0 and 1.35 or less.

[0012] The photosensitive resin composition according to this embodiment can provide a cured product pattern that exhibits excellent conformability to a substrate having recesses. The photosensitive resin composition can be used to form a photosensitive layer (photosensitive resin layer) on a substrate having recesses, and the photosensitive layer can then be exposed and developed to provide a cured product pattern with excellent conformability. The photosensitive resin composition according to this embodiment can provide a result of "A" or "B" in the evaluation of conformability (depth of recesses (etching depth): 3.5 μm) described in the Examples below.

[0013] The factors that enable a cured product pattern having excellent conformability to a substrate having recesses to be obtained are not entirely clear, but are presumed to be as follows. However, the factors are not limited to the following. That is, when the content of component (b) is 90 mass% or more based on the total amount of component (B), and the mass ratio of component (A) to component (B) is more than 0 and 1.35 or less, the photosensitive layer obtained using the photosensitive resin composition tends to be soft, and the melt viscosity of the photosensitive layer is reduced, and therefore, it is presumed that excellent conformability to a substrate having recesses can be obtained.

[0014] According to one aspect of the photosensitive resin composition according to this embodiment, a result of "A" or "B" can be obtained in the evaluation of conformability (depth of recess (etching depth): 5.0 μm) described in the examples below.

[0015] According to one aspect of the photosensitive resin composition of this embodiment, the hardness of the photosensitive layer can be reduced. According to one aspect of the photosensitive resin composition of this embodiment, in the evaluation of the hardness of the photosensitive layer described in the Examples below, an indentation depth of, for example, 9.0 μm or more (preferably, 9.5 μm or more, 10.0 μm or more, 10.5 μm or more, 11.0 μm or more, etc.) can be obtained.

[0016] When a photosensitive layer is formed on a substrate using a photosensitive resin composition, a film-like photosensitive resin composition may be laminated on the substrate to form a photosensitive layer (film-like photosensitive resin composition) on the substrate. According to one aspect of the photosensitive resin composition according to this embodiment, a photosensitive layer is obtained on a substrate having recesses using a film-like photosensitive resin composition, and then the photosensitive layer is exposed and developed, thereby obtaining a cured product pattern with excellent followability.

[0017] A cured product can be obtained by photocuring the photosensitive resin composition according to this embodiment. The cured product according to this embodiment is a cured product of the photosensitive resin composition according to this embodiment. One aspect of the photosensitive resin composition according to this embodiment can be used as a negative photosensitive resin composition. One aspect of the photosensitive resin composition according to this embodiment can be used to produce a cured product pattern, a resist pattern, a conductor pattern, or a wiring board.

[0018] The photosensitive resin composition according to this embodiment contains a binder polymer as component (A). Component (A) can have a polymerizable monomer as a monomer unit (structural unit), and can be obtained, for example, by radical polymerization of the polymerizable monomer.

[0019] The component (A) may contain (meth)acrylic acid as a monomer unit from the viewpoint of easily improving developability (e.g., alkaline developability), easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The content of the (meth)acrylic acid monomer unit in the component (A) may be within the following range based on the total amount of monomer units constituting the component (A), from the viewpoint of easily improving developability (e.g., alkaline developability), easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The content of the (meth)acrylic acid monomer unit may be 5% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, or 25% by mass or more. The content of the (meth)acrylic acid monomer unit may be 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, or 30% by mass or less. From these viewpoints, the content of the (meth)acrylic acid monomer unit may be 5 to 50 mass%, 5 to 40 mass%, 5 to 30 mass%, 10 to 50 mass%, 10 to 40 mass%, 10 to 30 mass%, 20 to 50 mass%, 20 to 40 mass%, or 20 to 30 mass%.

[0020] The component (A) may have an alkyl (meth)acrylate as a monomer unit from the viewpoint of easily improving developability (e.g., alkaline developability), easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. Examples of the alkyl group in the alkyl (meth)acrylate include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a undecyl group, and a dodecyl group. The alkyl group may be any of various structural isomers.

[0021] The alkyl (meth)acrylate may have an unsubstituted alkyl group or an alkyl group containing a substituent, such as a hydroxy group, a carboxy group, a carboxylate group, an aldehyde group, an alkoxy group, an ester group, a substituted or unsubstituted amino group, an amide group (excluding a hydroxyamide group), a hydroxyamide group, a nitro group, a cyano group, a mercapto group, or a halogeno group (such as a fluoro group, a chloro group, a bromo group, or an iodo group).

[0022] The number of carbon atoms in the alkyl group of the alkyl (meth)acrylate (including the number of carbon atoms in the substituent) may be 1 to 4, 1 to 3, or 1 to 2, from the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses.

[0023] The component (A) may have a hydroxyalkyl (meth)acrylate as a monomer unit from the viewpoint of easily improving developability (e.g., alkaline developability), easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. Examples of the hydroxyalkyl (meth)acrylate include hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, and hydroxyhexyl (meth)acrylate.

[0024] The content of alkyl (meth)acrylate monomer units in component (A) may be in the following ranges based on the total amount of monomer units constituting component (A): From the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses, the content of alkyl (meth)acrylate monomer units may be 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, 3.0% by mass or more, 3.5% by mass or more, 4.0% by mass or more, 4.5% by mass or more, or 5.0% by mass or more. From the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses, the content of the alkyl (meth)acrylate monomer unit may be 20% by mass or less, 15% by mass or less, 10% by mass or less, 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, or 5.0% by mass or less. The content of the alkyl (meth)acrylate monomer unit may be 4.5% by mass or less, 4.0% by mass or less, 3.5% by mass or less, or 3.0% by mass or less. From these viewpoints, the content of the alkyl (meth)acrylate monomer unit may be 0.5 to 20 mass%, 0.5 to 10 mass%, 0.5 to 8.0 mass%, 2.0 to 20 mass%, 2.0 to 10 mass%, 2.0 to 8.0 mass%, 4.0 to 20 mass%, 4.0 to 10 mass%, or 4.0 to 8.0 mass%.

[0025] The content of the hydroxyalkyl (meth)acrylate monomer unit in component (A) may be within the following ranges based on the total amount of monomer units constituting component (A), from the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The content of the hydroxyalkyl (meth)acrylate monomer unit may be 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, or 3.0% by mass or more. The content of the hydroxyalkyl (meth)acrylate monomer unit may be 20% by mass or less, 15% by mass or less, 10% by mass or less, 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.5% by mass or less, 4.0% by mass or less, 3.5% by mass or less, or 3.0% by mass or less. From these viewpoints, the content of the hydroxyalkyl (meth)acrylate monomer unit may be 0.5 to 20 mass%, 0.5 to 10 mass%, 0.5 to 8.0 mass%, 1.0 to 20 mass%, 1.0 to 10 mass%, 1.0 to 8.0 mass%, 2.0 to 20 mass%, 2.0 to 10 mass%, or 2.0 to 8.0 mass%.

[0026] The component (A) may contain a styrene compound as a monomer unit from the viewpoint of easily obtaining a cured product pattern with excellent resolution, from the viewpoint of easily reducing the hardness of the photosensitive layer, or from the viewpoint of easily obtaining a cured product pattern with excellent conformability to a substrate having recesses. Examples of the styrene compound include styrene and styrene derivatives. Examples of the styrene derivative include vinyl toluene and α-methyl styrene. The component (A) may contain styrene as a monomer unit from the viewpoint of easily reducing the hardness of the photosensitive layer or from the viewpoint of easily obtaining a cured product pattern with excellent conformability to a substrate having recesses.

[0027] The content of the monomer unit of the styrene compound in the component (A) may be in the following range based on the total amount of the monomer units constituting the component (A). From the viewpoint of easily obtaining a cured product pattern with excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses, the content of the monomer unit of the styrene compound may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, or 45% by mass or more. From the viewpoint of easily obtaining a cured product pattern with excellent resolution, the content of the monomer unit of the styrene compound may be 48% by mass or more or 50% by mass or more. The content of the monomer unit of the styrene compound may be 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, 50% by mass or less, 48% by mass or less, or 45% by mass or less from the viewpoint of easily increasing developability (e.g., alkali developability), easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. From these viewpoints, the content of the monomer unit of the styrene compound may be 10 to 80% by mass, 10 to 60% by mass, 10 to 48% by mass, 20 to 80% by mass, 20 to 60% by mass, 20 to 48% by mass, 35 to 80% by mass, 35 to 60% by mass, or 35 to 48% by mass.

[0028] The component (A) may have an aryl (meth)acrylate as a monomer unit from the viewpoint of easily obtaining a cured product pattern with excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses. Examples of the aryl (meth)acrylate include benzyl (meth)acrylate, phenyl (meth)acrylate, and naphthyl (meth)acrylate. The component (A) may have benzyl (meth)acrylate as a monomer unit from the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses.

[0029] The content of the aryl (meth)acrylate monomer unit in the component (A) may be in the following range based on the total amount of the monomer units constituting the component (A). From the viewpoint of easily obtaining a cured product pattern with excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses, the content of the aryl (meth)acrylate monomer unit may be 5% by mass or more, 10% by mass or more, 15% by mass or more, 18% by mass or more, 20% by mass or more, 22% by mass or more, or 23% by mass or more. From the viewpoint of easily obtaining a cured product pattern with excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses, the content of the aryl (meth)acrylate monomer unit may be 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 28% by mass or less, 25% by mass or less, or 23% by mass or less. From the viewpoint of facilitating the production of a cured product pattern having excellent resolution, the content of the aryl (meth)acrylate monomer unit may be 22% by mass or less, or 20% by mass or less. From these viewpoints, the content of the aryl (meth)acrylate monomer unit may be 5 to 50% by mass, 5 to 35% by mass, 5 to 25% by mass, 10 to 50% by mass, 10 to 35% by mass, 10 to 25% by mass, 22 to 50% by mass, 22 to 35% by mass, or 22 to 25% by mass.

[0030] From the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses, the component (A) may have at least one selected from the group consisting of (meth)acrylic acid, an alkyl (meth)acrylate, a styrene compound, and an aryl (meth)acrylate as a monomer unit, may have a styrene compound and an aryl (meth)acrylate as a monomer unit, may have an alkyl (meth)acrylate, a styrene compound, and an aryl (meth)acrylate as a monomer unit, or may have a hydroxyalkyl (meth)acrylate, a styrene compound, and an aryl (meth)acrylate as a monomer unit. In these cases, the content of at least one selected from the group consisting of a monomer unit of (meth)acrylic acid, a monomer unit of an alkyl (meth)acrylate, a monomer unit of a styrene compound, and a monomer unit of an aryl (meth)acrylate may be within the above-mentioned ranges.

[0031] Component (A) may contain, as a monomer unit, a monomer other than the above-mentioned monomers. Examples of such monomers include vinyl alcohol ethers (e.g., vinyl n-butyl ether), (meth)acrylonitrile, maleic acid, maleic anhydride, maleic acid monoesters (e.g., monomethyl maleate, monoethyl maleate, monoisopropyl maleate), fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid.

[0032] The acid value of the component (A) may be 100 mg KOH / g or more, 120 mg KOH / g or more, 140 mg KOH / g or more, 150 mg KOH / g or more, 160 mg KOH / g or more, 170 mg KOH / g or more, or 175 mg KOH / g or more from the viewpoint of easily improving developability (e.g., alkaline developability), easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having a recess. The acid value of the component (A) may be 250 mg KOH / g or less, 240 mg KOH / g or less, 230 mg KOH / g or less, 200 mg KOH / g or less, 190 mg KOH / g or less, or 180 mg KOH / g or less from the viewpoint of easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having a recess. From these viewpoints, the acid value of component (A) may be 100 to 250 mgKOH / g, 100 to 200 mgKOH / g, 100 to 180 mgKOH / g, 150 to 250 mgKOH / g, 150 to 200 mgKOH / g, 150 to 180 mgKOH / g, 170 to 250 mgKOH / g, 170 to 200 mgKOH / g, or 170 to 180 mgKOH / g. The acid value of component (A) can be adjusted by the content of monomer units (e.g., monomer units of (meth)acrylic acid) constituting component (A). The acid value can be measured by the method described in the Examples below.

[0033] The weight average molecular weight (Mw) of the component (A) may be 10,000 or more, 15,000 or more, 20,000 or more, 25,000 or more, 30,000 or more, 35,000 or more, 40,000 or more, 45,000 or more, or 50,000 or more from the viewpoint of easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern having excellent conformability to a substrate having recesses. The weight average molecular weight (Mw) of the component (A) may be 100,000 or less, 80,000 or less, 70,000 or less, 60,000 or less, 55,000 or less, or 50,000 or less from the viewpoint of easily improving the developability (e.g., alkaline developability), easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern having excellent conformability to a substrate having recesses. From the viewpoint of easily improving developability (e.g., alkali developability), the weight average molecular weight (Mw) of the component (A) may be no greater than 45,000, no greater than 40,000, or no greater than 35,000. From these viewpoints, the weight average molecular weight (Mw) of the component (A) may be 10,000 to 100,000, 10,000 to 80,000, 10,000 to 60,000, 30,000 to 100,000, 30,000 to 80,000, 30,000 to 60,000, 40,000 to 100,000, 40,000 to 80,000, or 40,000 to 60,000.

[0034] The number average molecular weight (Mn) of the component (A) may be 5,000 or more, 10,000 or more, 12,000 or more, 15,000 or more, 16,000 or more, 18,000 or more, 20,000 or more, or 21,000 or more from the viewpoint of easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The number average molecular weight (Mn) of the component (A) may be 50,000 or less, 45,000 or less, 40,000 or less, 35,000 or less, 30,000 or less, 25,000 or less, 22,000 or less, or 21,000 or less from the viewpoint of easily improving the developability (e.g., alkaline developability), easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. From the viewpoint of easily improving developability (e.g., alkali developability), the number average molecular weight (Mn) of the component (A) may be no greater than 20,000, no greater than 18,000, or no greater than 16,000. From these viewpoints, the number average molecular weight (Mn) of the component (A) may be 5,000 to 50,000, 5,000 to 40,000, 5,000 to 30,000, 10,000 to 50,000, 10,000 to 40,000, 10,000 to 30,000, 20,000 to 50,000, 20,000 to 40,000, or 20,000 to 30,000.

[0035] The dispersity (Mw / Mn) of the component (A) may be 1.0 or more, 1.5 or more, 2.0 or more, 2.1 or more, 2.2 or more, or 2.3 or more, from the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The dispersity (Mw / Mn) of the component (A) may be 3.0 or less, 2.8 or less, 2.6 or less, 2.5 or less, or 2.4 or less, from the viewpoint of easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to a substrate, easily obtaining a cured product pattern that has excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The dispersity (Mw / Mn) of the component (A) may be 2.3 or less, or 2.2 or less, from the viewpoint of easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to a substrate. From these viewpoints, the dispersity (Mw / Mn) of component (A) may be 1.0 to 3.0, 1.0 to 2.8, 1.0 to 2.5, 1.5 to 3.0, 1.5 to 2.8, 1.5 to 2.5, 2.0 to 3.0, 2.0 to 2.8, or 2.0 to 2.5.

[0036] The weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (Mw / Mn) can be measured by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene, and can be measured by the method described in the Examples below. For compounds with low molecular weights, if it is difficult to measure them using such a measurement method, the molecular weight may be measured by another method and the average may be calculated.

[0037] The content of the (A) component may be in the following range based on the total solid content of the photosensitive resin composition. From the viewpoint of easily obtaining excellent film formability, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses, the content of the (A) component may be 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, 50% by mass or more, or 52% by mass or more. From the viewpoint of easily obtaining excellent film formability, the content of the (A) component may be 53% by mass or more or 54% by mass or more. The content of the component (A) may be 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, 54% by mass or less, or 53% by mass or less from the viewpoint of easily obtaining excellent sensitivity, easily obtaining a cured product pattern with excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses. From these viewpoints, the content of the component (A) may be 20 to 90% by mass, 20 to 70% by mass, 20 to 60% by mass, 40 to 90% by mass, 40 to 70% by mass, 40 to 60% by mass, 50 to 90% by mass, 50 to 70% by mass, or 50 to 60% by mass.

[0038] The content of the (A) component may be in the following ranges relative to 100 parts by mass of the total of the (A) component and the (B) component. From the viewpoint of easily obtaining excellent film formability, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses, the content of the (A) component may be 20 parts by mass or more, 25 parts by mass or more, 30 parts by mass or more, 35 parts by mass or more, 40 parts by mass or more, 45 parts by mass or more, 50 parts by mass or more, or 55 parts by mass or more. From the viewpoint of easily obtaining excellent film formability, the content of the (A) component may be 56 parts by mass or more, or 57 parts by mass or more. The content of the component (A) may be 90 parts by mass or less, 85 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, 65 parts by mass or less, 60 parts by mass or less, 58 parts by mass or less, 57 parts by mass or less, 56 parts by mass or less, or 55 parts by mass or less, from the viewpoint of easily obtaining excellent sensitivity, easily obtaining a cured product pattern having excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern having excellent conformability to a substrate having recesses. From these viewpoints, the content of the component (A) may be 20 to 90 parts by mass, 20 to 70 parts by mass, 20 to 60 parts by mass, 40 to 90 parts by mass, 40 to 70 parts by mass, 40 to 60 parts by mass, 50 to 90 parts by mass, 50 to 70 parts by mass, or 50 to 60 parts by mass.

[0039] The photosensitive resin composition according to this embodiment contains a photopolymerizable compound as component (B). From the viewpoint of obtaining a cured product pattern that has excellent conformability to a substrate having recesses, component (B) contains a polyfunctional monomer having two or more radical reactive groups (reactive groups that react with radicals) and 8 to 16 oxyethylene groups as component (b).

[0040] The radical reactive group may be a group having an ethylenically unsaturated bond, such as a (meth)acryloyl group. In component (b), the number of radical reactive groups or the number of (meth)acryloyl groups (total of acryloyl groups and methacryloyl groups) may be 2 to 6, 2 to 5, 2 to 4, or 2 to 3, from the viewpoint of easily obtaining a cured product pattern with excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses.

[0041] The number of oxyethylene groups in component (b) (the total number of oxyethylene groups in component (b)) may be within the following ranges, from the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that exhibits excellent conformability to a substrate having recesses. The number of oxyethylene groups may be 8 or more, or 10 or more. The number of oxyethylene groups may be 16 or less, 14 or less, 12 or less, or 10 or less. From these viewpoints, the number of oxyethylene groups may be 8 to 16, 8 to 14, 8 to 12, 8 to 10, 10 to 16, 10 to 14, or 10 to 12. From the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that exhibits excellent conformability to a substrate having recesses, component (b) does not need to contain oxypropylene groups.

[0042] The molecular weight of component (b) may be within the following ranges from the viewpoint of easily increasing the toughness of the cured product pattern, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The molecular weight of component (b) may be 600 or more, 650 or more, 700 or more, 750 or more, 780 or more, or 800 or more. The molecular weight of component (b) may be 1200 or less, 1150 or less, 1100 or less, 1050 or less, 1000 or less, 950 or less, 900 or less, or 850 or less. From these viewpoints, the molecular weight of component (b) may be 600 to 1200, 600 to 1000, 600 to 900, 700 to 1200, 700 to 1000, 700 to 900, 800 to 1200, 800 to 1000, or 800 to 900.

[0043] From the viewpoint of easily obtaining a cured product pattern with excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses, component (b) may have at least one skeleton selected from the group consisting of a bisphenol A skeleton and a ditrimethylolpropane skeleton, or may have a bisphenol A skeleton. Component (b) may contain a (meth)acrylic acid compound having a bisphenol A skeleton as a polyfunctional monomer having a bisphenol A skeleton. Examples of (meth)acrylic acid compounds having a bisphenol A skeleton include EO-modified bisphenol A di(meth)acrylate (EO groups: 8 to 16). Component (b) may contain a (meth)acrylic acid compound having a ditrimethylolpropane skeleton as a polyfunctional monomer having a ditrimethylolpropane skeleton. Examples of (meth)acrylic acid compounds having a ditrimethylolpropane skeleton include EO-modified ditrimethylolpropane tetra(meth)acrylate (EO groups: 8 to 16). From the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses, the component (b) may include at least one selected from the group consisting of (meth)acrylic acid compounds having a bisphenol A skeleton and (meth)acrylic acid compounds having a ditrimethylolpropane skeleton, and may include a (meth)acrylic acid compound having a bisphenol A skeleton.

[0044] Component (B) may contain a photopolymerizable compound other than component (b). Examples of such a photopolymerizable compound include a monofunctional monomer, a polyfunctional monomer having 7 or less oxyethylene groups, and a polyfunctional monomer having 17 or more oxyethylene groups.

[0045] The content of component (b) is 90% by mass or more based on the total amount of component (B), from the viewpoint of easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The content of component (b) may be 92% by mass or more, 95% by mass or more, 96% by mass or more, 97% by mass or more, 98% by mass or more, or 99% by mass or more based on the total amount of component (B), from the viewpoint of easily obtaining a cured product pattern that has excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The content of component (b) may be 100% by mass or less based on the total amount of component (B). The component (B) does not need to contain a monofunctional monomer, from the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses.

[0046] The content B1 of the component (B) or the component (b) may be in the following range based on the total solid content of the photosensitive resin composition. From the viewpoint of easily obtaining excellent sensitivity, easily obtaining a cured product pattern with excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses, the content B1 may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 41% by mass or more, or 42% by mass or more. From the viewpoint of easily obtaining excellent film formability, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses, the content B1 may be 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, 50% by mass or less, or 45% by mass or less. From the viewpoint of easily obtaining excellent film formability, the content B1 may be 43% by mass or less, 42% by mass or less, or 41% by mass or less, and from these viewpoints, the content B1 may be 10 to 80% by mass, 10 to 60% by mass, 10 to 50% by mass, 30 to 80% by mass, 30 to 60% by mass, 30 to 50% by mass, 40 to 80% by mass, 40 to 60% by mass, or 40 to 50% by mass.

[0047] The content B2 of the component (B) or the component (b) may be in the following range relative to 100 parts by mass of the total of the components (A) and (B): From the viewpoint of easily obtaining excellent sensitivity, easily obtaining a cured product pattern with excellent resolution, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses, the content B2 may be 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more, 25 parts by mass or more, 30 parts by mass or more, 35 parts by mass or more, 40 parts by mass or more, 42 parts by mass or more, 43 parts by mass or more, 44 parts by mass or more, or 45 parts by mass or more. The content B2 may be 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, 65 parts by mass or less, 60 parts by mass or less, 55 parts by mass or less, 50 parts by mass or less, or 45 parts by mass or less from the viewpoint of easily obtaining excellent film formability, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The content B2 may be 44 parts by mass or less, or 43 parts by mass or less from the viewpoint of easily obtaining excellent film formability. From these viewpoints, the content B2 may be 10 to 80 parts by mass, 10 to 60 parts by mass, 10 to 50 parts by mass, 30 to 80 parts by mass, 30 to 60 parts by mass, 30 to 50 parts by mass, 40 to 80 parts by mass, 40 to 60 parts by mass, or 40 to 50 parts by mass.

[0048] The mass ratio of the component (A) to the component (B) (content of the component (A) / content of the component (B): hereinafter referred to as "mass ratio A / B") is greater than 0 and not more than 1.35, from the viewpoint of obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The mass ratio A / B may be 1.33 or less, 1.30 or less, 1.28 or less, 1.27 or less, 1.25 or less, 1.23 or less, or 1.22 or less, from the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. From the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses, the mass ratio A / B may be 0.10 or more, 0.30 or more, 0.50 or more, 0.60 or more, 0.80 or more, 1.00 or more, more than 1.00, 1.05 or more, 1.10 or more, 1.15 or more, 1.20 or more, or 1.22 or more. The mass ratio A / B may be 1.23 or more, 1.25 or more, 1.27 or more, 1.28 or more, 1.30 or more, or 1.33 or more. From these viewpoints, the mass ratio A / B may be greater than 0 and less than 1.30, greater than 0 and less than 1.25, 1.00 to 1.35, 1.00 to 1.30, 1.00 to 1.25, 1.10 to 1.35, 1.10 to 1.30, 1.10 to 1.25, 1.20 to 1.35, 1.20 to 1.30, or 1.20 to 1.25.

[0049] The mass ratio of the (A) component to the (b) component (content of the (A) component / content of the (b) component: hereinafter referred to as "mass ratio A / b") may be 1.35 or less, 1.33 or less, 1.30 or less, 1.28 or less, 1.27 or less, 1.25 or less, 1.23 or less, or 1.22 or less, from the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The mass ratio A / b may be more than 0, 0.10 or more, 0.30 or more, 0.50 or more, 0.60 or more, 0.80 or more, 1.00 or more, more than 1.00, 1.05 or more, 1.10 or more, 1.15 or more, 1.20 or more, or 1.22 or more, from the viewpoint of easily reducing the hardness of the photosensitive layer or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The mass ratio A / b may be 1.23 or more, 1.25 or more, 1.27 or more, 1.28 or more, 1.30 or more, or 1.33 or more. From these viewpoints, the mass ratio A / b may be more than 0 and 1.35 or less, more than 0 and 1.30 or less, more than 0 and 1.25 or less, 1.00 to 1.35, 1.00 to 1.30, 1.00 to 1.25, 1.10 to 1.35, 1.10 to 1.30, 1.10 to 1.25, 1.20 to 1.35, 1.20 to 1.30, or 1.20 to 1.25.

[0050] The photosensitive resin composition according to this embodiment contains a photopolymerization initiator as component (C). As component (C), a photopolymerization initiator capable of polymerizing component (B) can be used.

[0051] Examples of the component (C) include hexaarylbiimidazole compounds; aromatic ketones such as benzophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propanone-1; alkyl aryl ketones such as benzophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone ... quinones such as trichloroquinone; benzoin ether compounds such as benzoin alkyl ether; benzoin compounds such as benzoin and alkylbenzoin; benzyl derivatives such as benzyl dimethyl ketal; and phosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethylbenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide.

[0052] The component (C) may contain a hexaarylbiimidazole compound from the viewpoints of easily obtaining excellent sensitivity, easily obtaining a cured product pattern with excellent resolution, easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses. The aryl group in the hexaarylbiimidazole compound may be a phenyl group or the like. The hydrogen atom bonded to the aryl group in the hexaarylbiimidazole compound may be substituted with a halogen atom (such as a chlorine atom).

[0053] The hexaarylbiimidazole compound may be a 2,4,5-triarylimidazole dimer, such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-bis-(m-methoxyphenyl)imidazole dimer, or 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer. The hexaarylbiimidazole compound may contain 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer or 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole from the viewpoint of easily obtaining excellent sensitivity, easily obtaining a cured product pattern with excellent resolution, easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to a substrate, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses.

[0054] The content of the hexaarylbiimidazole compound may be 90% by mass or more, 92% by mass or more, 93% by mass or more, 95% by mass or more, 97% by mass or more, or 99% by mass or more, based on the total amount of component (C), from the viewpoint of easily obtaining excellent sensitivity, easily obtaining a cured product pattern with excellent resolution, easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern with excellent conformability to a substrate having recesses. The content of the hexaarylbiimidazole compound may be 100% by mass or less, based on the total amount of component (C).

[0055] The content of component (C) may be within the following ranges based on the total solid content of the photosensitive resin composition, from the viewpoint of easily improving both sensitivity and resolution in a balanced manner, easily reducing the hardness of the photosensitive layer, or easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The content of component (C) may be 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, or 3.0% by mass or more. The content of component (C) may be 20% by mass or less, 15% by mass or less, 10% by mass or less, 8.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.5% by mass or less, 4.0% by mass or less, or 3.5% by mass or less. From these viewpoints, the content of the component (C) may be 0.1 to 20 mass%, 0.1 to 10 mass%, 0.1 to 5.0 mass%, 1.0 to 20 mass%, 1.0 to 10 mass%, 1.0 to 5.0 mass%, 3.0 to 20 mass%, 3.0 to 10 mass%, or 3.0 to 5.0 mass%.

[0056] The content of the component (C) may be within the following ranges relative to 100 parts by mass of the total of the components (A) and (B), from the viewpoints of easily improving both sensitivity and resolution in a balanced manner, easily reducing the hardness of the photosensitive layer, and easily obtaining a cured product pattern that has excellent conformability to a substrate having recesses. The content of the component (C) may be 0.1 parts by mass or more, 0.5 parts by mass or more, 1.0 parts by mass or more, 1.5 parts by mass or more, 2.0 parts by mass or more, 2.5 parts by mass or more, 3.0 parts by mass or more, or 3.5 parts by mass or more. The content of the component (C) may be 20 parts by mass or less, 15 parts by mass or less, 10 parts by mass or less, 8.0 parts by mass or less, 6.0 parts by mass or less, 5.0 parts by mass or less, 4.5 parts by mass or less, 4.0 parts by mass or less, or 3.5 parts by mass or less. From these viewpoints, the content of the (C) component may be 0.1 to 20 parts by mass, 0.1 to 10 parts by mass, 0.1 to 5.0 parts by mass, 1.0 to 20 parts by mass, 1.0 to 10 parts by mass, 1.0 to 5.0 parts by mass, 3.0 to 20 parts by mass, 3.0 to 10 parts by mass, or 3.0 to 5.0 parts by mass.

[0057] The photosensitive resin composition according to this embodiment may contain a sensitizer as component (D), which makes it easier to effectively utilize the absorption wavelength of actinic rays used for exposure.

[0058] Examples of the component (D) include dialkylaminobenzophenone compounds, pyrazoline compounds, coumarin compounds, anthracene compounds, xanthone compounds, thioxanthone compounds, oxazole compounds, benzoxazole compounds, thiazole compounds, benzothiazole compounds, triazole compounds, stilbene compounds, triazine compounds, thiophene compounds, naphthalimide compounds, triarylamine compounds, and aminoacridine compounds.

[0059] Examples of the dialkylaminobenzophenone compound include 4,4'-bis(diethylamino)benzophenone and 4-methoxy-4'-dimethylaminobenzophenone.

[0060] Examples of the pyrazoline compound include 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)pyrazoline, 1-phenyl-3-(4-tert-butylstyryl)-5-(4-tert-butylphenyl)pyrazoline, and 1-phenyl-3-biphenyl-5-(4-tert-butylphenyl)pyrazoline.

[0061] Examples of coumarin compounds include 3-benzoyl-7-diethylaminocoumarin, 7-diethylamino-4-methylcoumarin, 3,3'-carbonylbis(7-diethylaminocoumarin), 2,3,6,7-tetrahydro-9-methyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quillodin-11-one, and the like.

[0062] Examples of the anthracene compound include 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-dibutoxyanthracene, and 9,10-dipentoxyanthracene.

[0063] From the viewpoint of easily obtaining a cured product pattern with excellent resolution, the component (D) may contain a dialkylaminobenzophenone compound or may contain 4,4'-bis(diethylamino)benzophenone.

[0064] The content of the (D) component may be within the following ranges based on the total solid content of the photosensitive resin composition, from the viewpoint of easily obtaining excellent sensitivity, easily obtaining a cured product pattern with excellent resolution, or easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate. The content of the (D) component may be 0.001% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.02% by mass or more, 0.03% by mass or more, or 0.04% by mass or more. The content of the (D) component may be 3.0% by mass or less, 2.0% by mass or less, 1.0% by mass or less, 0.5% by mass or less, 0.3% by mass or less, 0.1% by mass or less, 0.08% by mass or less, 0.05% by mass or less, or 0.045% by mass or less. From these viewpoints, the content of the (D) component may be 0.001 to 3.0 mass%, 0.001 to 1.0 mass%, 0.001 to 0.1 mass%, 0.01 to 3.0 mass%, 0.01 to 1.0 mass%, 0.01 to 0.1 mass%, 0.03 to 3.0 mass%, 0.03 to 1.0 mass%, or 0.03 to 0.1 mass%.

[0065] The content of component (D) may be within the following ranges relative to 100 parts by mass of the total of components (A) and (B), from the viewpoints of easily obtaining excellent sensitivity, easily obtaining a cured product pattern with excellent resolution, or easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate. The content of component (D) may be 0.001 parts by mass or more, 0.005 parts by mass or more, 0.01 parts by mass or more, 0.02 parts by mass or more, 0.03 parts by mass or more, 0.04 parts by mass or more, more than 0.04 parts by mass, or 0.041 parts by mass or more. The content of component (D) may be 3.0 parts by mass or less, 2.0 parts by mass or less, 1.0 parts by mass or less, 0.5 parts by mass or less, 0.3 parts by mass or less, 0.1 parts by mass or less, 0.08 parts by mass or less, 0.05 parts by mass or less, or 0.045 parts by mass or less. From these viewpoints, the content of the (D) component may be 0.001 to 3.0 parts by mass, 0.001 to 1.0 parts by mass, 0.001 to 0.1 parts by mass, 0.01 to 3.0 parts by mass, 0.01 to 1.0 parts by mass, 0.01 to 0.1 parts by mass, 0.03 to 3.0 parts by mass, 0.03 to 1.0 parts by mass, or 0.03 to 0.1 parts by mass.

[0066] The photosensitive resin composition according to this embodiment may contain a polymerization inhibitor as component (E) from the viewpoint of easily obtaining a cured product pattern with excellent resolution. Examples of the polymerization inhibitor include 4-tert-butylcatechol, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, p-methoxyphenol, diphenyl-p-benzoquinone, benzoquinone, hydroquinone, pyrogallol, phenothiazine, resorcinol, ortho-dinitrobenzene, para-dinitrobenzene, meta-dinitrobenzene, phenanthraquinone, N-phenyl-2-naphthylamine, cupferron, 2,5-toluquinone, tannic acid, parabenzylaminophenol, tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid, and nitrosamines. From the viewpoint of easily obtaining a cured product pattern with excellent resolution, the component (E) may contain at least one member selected from the group consisting of 4-tert-butylcatechol and 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl.

[0067] The content of the component (E) may be in the following range based on the total solid content of the photosensitive resin composition. From the viewpoint of easily obtaining excellent sensitivity or easily obtaining a cured product pattern with excellent resolution, the content of the component (E) may be 0.001 mass% or more, 0.005 mass% or more, 0.01 mass% or more, 0.02 mass% or more, 0.03 mass% or more, or 0.035 mass% or more. From the viewpoint of easily obtaining excellent sensitivity or easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate, the content of the component (E) may be 3.0 mass% or less, 2.0 mass% or less, 1.0 mass% or less, 0.5 mass% or less, 0.3 mass% or less, 0.1 mass% or less, 0.08 mass% or less, 0.05 mass% or less, or 0.04 mass% or less. From these viewpoints, the content of the component (E) may be 0.001 to 3.0 mass%, 0.001 to 1.0 mass%, 0.001 to 0.1 mass%, 0.01 to 3.0 mass%, 0.01 to 1.0 mass%, 0.01 to 0.1 mass%, 0.03 to 3.0 mass%, 0.03 to 1.0 mass%, or 0.03 to 0.1 mass%.

[0068] The content of the component (E) may be in the following ranges relative to 100 parts by mass of the total of the component (A) and the component (B). From the viewpoint of easily obtaining excellent sensitivity or easily obtaining a cured product pattern with excellent resolution, the content of the component (E) may be 0.001 parts by mass or more, 0.005 parts by mass or more, 0.01 parts by mass or more, 0.02 parts by mass or more, 0.03 parts by mass or more, or 0.04 parts by mass or more. From the viewpoint of easily obtaining excellent sensitivity or easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate, the content of the component (E) may be 3.0 parts by mass or less, 2.0 parts by mass or less, 1.0 parts by mass or less, 0.5 parts by mass or less, 0.3 parts by mass or less, 0.1 parts by mass or less, 0.08 parts by mass or less, 0.05 parts by mass or less, or 0.04 parts by mass or less. From these viewpoints, the content of the (E) component may be 0.001 to 3.0 parts by mass, 0.001 to 1.0 parts by mass, 0.001 to 0.1 parts by mass, 0.01 to 3.0 parts by mass, 0.01 to 1.0 parts by mass, 0.01 to 0.1 parts by mass, 0.03 to 3.0 parts by mass, 0.03 to 1.0 parts by mass, or 0.03 to 0.1 parts by mass.

[0069] The photosensitive resin composition according to this embodiment may contain an organic solvent, such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, or propylene glycol monomethyl ether, in order to facilitate viscosity adjustment.

[0070] The photosensitive resin composition according to this embodiment may contain components other than those described above. Examples of such components include hydrogen donors (such as bis[4-(dimethylamino)phenyl]methane, bis[4-(diethylamino)phenyl]methane, N-phenylglycine, and leucocrystal violet), dyes (such as malachite green), tribromophenyl sulfone, photocoloring agents, thermal color-developing inhibitors, plasticizers (such as p-toluenesulfonamide), pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion promoters (such as a mixture of carboxybenzotriazole, 5-amino-1H-tetrazole, and methoxypropanol), leveling agents, release promoters, antioxidants, fragrances, imaging agents, and thermal crosslinking agents. The content of each of these components may be 0.001 parts by mass or more, 0.005 parts by mass or more, or 0.01 parts by mass or more, and may be 20 parts by mass or less, 10 parts by mass or less, or 5 parts by mass or less, relative to 100 parts by mass of the total of the (A) component and the (B) component.

[0071] The photosensitive resin composition according to this embodiment may be in the form of a film. The thickness of the film-like photosensitive resin composition may be 1 μm or more, 5 μm or more, 10 μm or more, 15 μm or more, more than 15 μm, 16 μm or more, 18 μm or more, 20 μm or more, or 25 μm or more, from the viewpoint of easily improving productivity. The thickness of the film-like photosensitive resin composition may be 100 μm or less, 80 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, or 25 μm or less, from the viewpoint of easily obtaining a cured product pattern with excellent resolution, or easily improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition to the substrate. From these viewpoints, the thickness of the film-like photosensitive resin composition may be 1 to 100 μm, 1 to 60 μm, 1 to 30 μm, 10 to 100 μm, 10 to 60 μm, 10 to 30 μm, 20 to 100 μm, 20 to 60 μm, or 20 to 30 μm.

[0072] The photosensitive element according to this embodiment includes a support and a photosensitive layer (photosensitive resin layer) disposed on the support, and the photosensitive layer contains the photosensitive resin composition according to this embodiment. The photosensitive element according to this embodiment may include a protective layer disposed on the photosensitive layer. FIG. 1 is a schematic cross-sectional view showing an example of a photosensitive element. The photosensitive element 10 in FIG. 1 includes a support 12, a photosensitive layer 14 disposed on the support 12, and a protective layer 16 disposed on the photosensitive layer 14. The protective layer 16 is disposed on the opposite side of the photosensitive layer 14 from the support 12.

[0073] The support may be a polymer film having heat resistance and solvent resistance, such as polyester films such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene-2,6-naphthalate (PEN); or polyolefin films such as polyethylene and polypropylene.

[0074] The thickness of the support may be 1 μm or more, 5 μm or more, 10 μm or more, or 15 μm or more, from the viewpoint of easily preventing damage to the support when peeling the support from the photosensitive layer. The thickness of the support may be 100 μm or less, 50 μm or less, 30 μm or less, or 20 μm or less, from the viewpoint of easily and suitably exposing when exposing through the support. From these viewpoints, the thickness of the support may be 1 to 100 μm.

[0075] The photosensitive layer may include the photosensitive resin composition according to the present embodiment, and may be made of the photosensitive resin composition according to the present embodiment. The thickness of the photosensitive layer (the thickness after volatilizing the organic solvent in the case where the photosensitive resin composition contains an organic solvent) may be within the ranges described above for the thickness of the film-like photosensitive resin composition.

[0076] The protective layer may be a polymer film having heat resistance and solvent resistance, such as a polyester film such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polyethylene-2,6-naphthalate (PEN); or a polyolefin film such as a polyethylene film or polypropylene film.

[0077] The thickness of the protective layer may be 1 μm or more, 5 μm or more, 10 μm or more, 15 μm or more, 20 μm or more, or 25 μm or more, from the viewpoint of easily suppressing damage to the protective layer when laminating the photosensitive layer and the support onto the substrate while peeling off the protective layer. The thickness of the protective layer may be 100 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less, from the viewpoint of easily improving productivity. From these viewpoints, the thickness of the protective layer may be 1 to 100 μm.

[0078] The photosensitive element according to this embodiment may include a cushion layer, an adhesive layer, a light absorbing layer, a gas barrier layer, and the like.

[0079] The method for producing a cured product pattern according to this embodiment (e.g., a method for producing a resist pattern) includes the steps of forming a photosensitive layer on a substrate using the photosensitive resin composition according to this embodiment (photosensitive layer forming step), photocuring a portion of the photosensitive layer (exposure step), and removing at least a portion (partial or all) of the uncured portion of the photosensitive layer to form a cured product pattern (e.g., a resist pattern) (developing step). The resist pattern may be referred to as a photocured product pattern of the photosensitive resin composition, a relief pattern, or the like.

[0080] The substrate may include a conductor layer, or may include an insulating layer and a conductor layer disposed on the insulating layer. Examples of the substrate include, but are not limited to, a circuit-forming substrate including an insulating layer and a conductor layer disposed on the insulating layer; a die pad (substrate for lead frame) such as an alloy substrate; and the like.

[0081] In the photosensitive layer forming step, a photosensitive layer is formed on a substrate using the photosensitive resin composition according to this embodiment. In the photosensitive layer forming step, a photosensitive layer (film-like photosensitive resin composition) may be formed on a substrate by laminating a film-like photosensitive resin composition on a substrate, or a photosensitive layer may be formed on a substrate by laminating a photosensitive layer in a photosensitive element according to this embodiment on a substrate. In the photosensitive layer forming step, the photosensitive layer and the support may be formed on a substrate by laminating the photosensitive layer of the photosensitive element and the support on a substrate in a state where the photosensitive layer of the photosensitive element according to this embodiment is located closer to the substrate than the support. When the photosensitive element according to this embodiment has a protective layer, the protective layer may be removed from the photosensitive element and then the photosensitive layer may be laminated on the substrate. When the photosensitive layer of the photosensitive element according to this embodiment is laminated on a substrate, the photosensitive layer may be pressed against the substrate while being heated. The heating temperature during compression bonding may be 70 to 130°C, and the pressure during compression bonding may be 0.1 to 1.0 MPa (1 to 10 kgf / cm ２ These conditions can be appropriately selected as necessary. The photosensitive layer forming step may be carried out under reduced pressure.

[0082] In the exposure step, a portion of the photosensitive layer is photocured. In the exposure step, the photosensitive layer may be exposed to actinic rays to photocure a portion of the photosensitive layer, or the photosensitive layer may be exposed to actinic rays through a support. In the exposure step, the exposed portion irradiated with actinic rays may be photocured to form a photocured portion (latent image).

[0083] As the exposure method, known exposure methods can be applied, including a method of irradiating an actinic ray in an imagewise manner through a negative or positive mask pattern called artwork (mask exposure method), an LDI (Laser Direct Imaging) exposure method, and a method of irradiating an actinic ray in an imagewise manner through a lens using an actinic ray projected from an image of a photomask (projection exposure method). Among these, the LDI exposure method or the projection exposure method can be used from the viewpoint of easily obtaining excellent resolution. The projection exposure method can also be said to be an exposure method using actinic ray with attenuated energy.

[0084] The light source of actinic rays is not particularly limited as long as it is a commonly used known light source, and a light source that effectively emits ultraviolet rays can be used. Examples of light sources that effectively emit ultraviolet rays include carbon arc lamps, mercury vapor arc lamps, ultra-high pressure mercury lamps, high-pressure mercury lamps, xenon lamps, gas lasers (argon lasers, etc.), solid-state lasers (YAG lasers, etc.), and semiconductor lasers (gallium nitride blue-violet lasers, etc.). Among these, from the viewpoint of easily improving the resolution and alignment in a well-balanced manner, a light source that can emit i-line monochromatic light with an exposure wavelength of 365 nm, a light source that can emit h-line monochromatic light with an exposure wavelength of 405 nm, or a light source that can emit actinic rays with an exposure wavelength of i, h, and g crosstalk can be used, and a light source that can emit i-line monochromatic light with an exposure wavelength of 365 nm or h-line monochromatic light with an exposure wavelength of 405 nm can be used. Examples of light sources that can emit i-line monochromatic light with an exposure wavelength of 365 nm include ultra-high pressure mercury lamps. A light source capable of emitting monochromatic h-line light with an exposure wavelength of 405 nm includes a blue-violet laser diode with an exposure wavelength of 405 nm.

[0085] In the development step, at least a portion of the uncured portion of the photosensitive layer is removed to form a cured product pattern (photocured portion of the photosensitive layer). If a support is placed on the photosensitive layer in the exposure step, the support may be peeled off before the development step. The development method may be wet development or dry development.

[0086] In the case of wet development, development can be performed by a known wet development method using a developer suitable for the photosensitive resin composition. Examples of wet development methods include a dipping method, a paddle method, a high-pressure spray method, brushing, scrubbing, and a rocking immersion method. One type of wet development method may be used alone, or two or more types may be used in combination.

[0087] The developer can be appropriately selected depending on the composition of the photosensitive resin composition, and examples of the developer include an alkaline aqueous solution and an organic solvent developer.

[0088] From the viewpoints of safety, stability, and ease of use, an alkaline aqueous solution may be used as the developer. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium, or potassium hydroxide; alkali carbonates such as carbonates or bicarbonates of lithium, sodium, potassium, or ammonium; alkali metal phosphates such as potassium phosphate and sodium phosphate; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; sodium borate; sodium metasilicate; tetramethylammonium hydroxide; ethanolamine; ethylenediamine; diethylenetriamine; 2-amino-2-hydroxymethyl-1,3-propanediol; 1,3-diamino-2-propanol; and morpholine.

[0089] Examples of alkaline aqueous solutions include a dilute solution of 0.1 to 5% by mass sodium carbonate, a dilute solution of 0.1 to 5% by mass potassium carbonate, a dilute solution of 0.1 to 5% by mass sodium hydroxide, and a dilute solution of 0.1 to 5% by mass sodium tetraborate. The pH of the alkaline aqueous solution used for development may be in the range of 9 to 11. The temperature of the alkaline aqueous solution can be adjusted according to the developability of the photosensitive layer. The alkaline aqueous solution may contain a surfactant, an antifoaming agent, a small amount of an organic solvent to promote development, and the like.

[0090] Examples of organic solvents used in the alkaline aqueous solution include 3-acetone alcohol, acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

[0091] Examples of organic solvents used in the organic solvent developer include 1,1,1-trichloroethane, N-methyl-2-pyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, γ-butyrolactone, etc. From the viewpoint of preventing ignition, the content of the organic solvent may be adjusted to the range of 1 to 20 mass % by adding water to the organic solvent developer.

[0092] In the method for producing a cured product pattern according to this embodiment, post-exposure baking (PEB) may be performed after the exposure step and before the development step. The temperature of the post-exposure baking may be 50 to 100° C. Examples of the heater that may be used include a hot plate, a box dryer, and a heating roll.

[0093] In the method for producing a cured product pattern according to this embodiment, after removing at least a portion of the uncured portion in the development step, heating at 60 to 250°C or 0.2 to 10 J / cm ２ The cured product pattern may be further cured by performing exposure in an amount of 1000 ppm or more.

[0094] The method for producing a conductor pattern according to this embodiment includes a step of forming a conductor pattern using, as a mask, a cured product pattern (resist pattern) obtained by the method for producing a cured product pattern according to this embodiment. In the method for producing a conductor pattern according to this embodiment, the conductor pattern may be formed by plating or etching using, as a mask, the cured product pattern (resist pattern) obtained by the method for producing a cured product pattern according to this embodiment. Alternatively, the conductor pattern may be formed by plating or etching a substrate on which a cured product pattern obtained by the method for producing a cured product pattern according to this embodiment has been formed. Examples of materials constituting the conductor pattern include copper, solder, nickel, and gold.

[0095] In the method for producing a conductor pattern according to the first embodiment, a conductor pattern is formed by plating at least a portion (partial or all) of a portion of a substrate where a cured product pattern is not formed, using the cured product pattern obtained by the method for producing a cured product pattern according to the present embodiment as a mask. In the method for producing a conductor pattern according to the first embodiment, the substrate may include a conductor layer, and with the cured product pattern obtained by the method for producing a cured product pattern according to the present embodiment formed on the conductor layer, the conductor pattern may be formed by plating at least a portion (partial or all) of a portion of the conductor layer of the substrate where the cured product pattern is not formed, using the cured product pattern as a mask. The materials of the conductor layer of the substrate and the plating layer (conductor layer) formed by the plating process may be the same or different. When the conductor layer of the substrate and the plating layer (conductor layer) formed by the plating process are the same material, the conductor layer and the plating layer may be integrated. The plating process may be electrolytic plating or electroless plating. Examples of plating processes include copper plating, solder plating, nickel plating, and gold plating.

[0096] In the method for producing a conductor pattern according to the second embodiment, a substrate is provided with a conductor layer, and in a state in which a cured product pattern obtained by the method for producing a cured product pattern according to the present embodiment is formed on the conductor layer, the cured product pattern (resist pattern) is used as a mask to etch away at least a portion (partial or all) of the conductor layer that is not covered by the cured product pattern, thereby forming a conductor pattern covered by the cured product pattern. The etching method is appropriately selected depending on the conductor layer to be removed.

[0097] The method for producing a conductive pattern according to this embodiment may include a step of removing the cured pattern from the substrate after the plating or etching process described above. The cured pattern can be removed, for example, with an aqueous solution that is more alkaline than the aqueous solution used in the developing process.

[0098] In the method for producing a conductive pattern according to the first embodiment, when the substrate has a conductive layer, after removing the cured product pattern, the portion of the conductive layer of the substrate that was covered with the cured product pattern may be removed by etching (e.g., flash etching). The etching method is appropriately selected depending on the conductive layer to be removed.

[0099] One aspect of the method for producing a conductor pattern according to this embodiment is a method for producing a wiring board (e.g., a method for producing a printed wiring board), which includes a step of forming a wiring pattern (e.g., a circuit) as a conductor pattern using, as a mask, a cured product pattern obtained by the method for producing a cured product pattern according to this embodiment. The wiring board according to this embodiment can be obtained by the method for producing a wiring board according to this embodiment. The wiring board according to this embodiment may be a single-layer printed wiring board, a multilayer printed wiring board, or a printed wiring board having small-diameter through holes.

[0100] FIG. 2 is a schematic cross-sectional view showing an example of a method for producing a conductor pattern (semi-additive process). In FIG. 2(a), a substrate 20 is prepared. The substrate 20 includes an insulating layer 22 and a conductor layer 24 disposed on the insulating layer 22. The conductor layer 24 is, for example, a copper layer. In FIG. 2(b), the protective layer 16 of the photosensitive element 10 in FIG. 1 is peeled off, and then the photosensitive layer 14 of the photosensitive element 10 and the support 12 are laminated on the substrate 20 (photosensitive layer formation step). In FIG. 2(c), the photosensitive layer 14 is irradiated through the support 12 with actinic light L projected with a photomask image (projection exposure method exposure step). In FIG. 2(d), portions of the photosensitive layer 14 other than the photocured portion are removed from the substrate 20, thereby forming a cured product pattern 14a (photocured portion of the photosensitive layer 14) on the substrate 20 (development step). In (e) of Fig. 2, a plating process is performed using the cured product pattern 14a as a mask to form a plating layer 30 on the conductor layer 24 that is not covered by the cured product pattern 14a in the substrate 20. In (f) of Fig. 2, the cured product pattern 14a is removed, and then the portion of the conductor layer 24 that was covered by the cured product pattern 14a is removed to form a conductor layer 24a. This forms a conductor pattern 40 composed of the conductor layer 24a and the plating layer 30.

[0101] The present disclosure will be explained in more detail below using examples, but the present disclosure is not limited to these examples.

[0102] <Preparation of Binder Polymer> (Binder Polymer A1) A solution (a) was prepared by mixing 27 parts by mass of methacrylic acid, 45 parts by mass of styrene, 23 parts by mass of benzyl methacrylate, 5 parts by mass of methyl methacrylate, and 0.9 parts by mass of azobisisobutyronitrile. A solution (b) was prepared by dissolving 0.5 parts by mass of azobisisobutyronitrile in 50 parts by mass of a mixed solution (x) of 30 parts by mass of 1-methoxy-2-propanol and 20 parts by mass of toluene.

[0103] 500 parts by mass of a mixed solution (x1) containing 300 parts by mass of 1-methoxy-2-propanol and 200 parts by mass of toluene was placed in a flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel, and nitrogen gas inlet tube. Then, nitrogen gas was blown into the flask while stirring the mixed solution (x1). The mixed solution (x1) was heated to 80°C. Next, the above-described solution (a) was added dropwise to the mixed solution (x1) at a constant dropwise rate over 4 hours to obtain a mixed solution (x2), and the mixed solution (x2) was stirred at 80°C for 2 hours. Next, the above-described solution (b) was added dropwise to the mixed solution (x2) at a constant dropwise rate over 10 minutes to obtain a mixed solution (x3). The mixed solution (x3) was then stirred at 80°C for 3 hours. Next, while stirring the mixed solution (x3), the mixed solution (x3) was heated to 95°C over 30 minutes, and then the mixed solution (x3) was kept at 95°C for 2 hours. After stopping the stirring, the mixed solution (x3) was cooled to room temperature (25°C) to obtain a solution of binder polymer A1. The non-volatile content (solid content) of the binder polymer A1 solution was 49 mass%. The binder polymer A1 had a weight average molecular weight (Mw) of 50,000, a number average molecular weight (Mn) of 21,000, and an acid value of 176 mgKOH / g.

[0104] The weight-average molecular weight and number-average molecular weight were measured by gel permeation chromatography (GPC) under the following conditions and calculated using a calibration curve of standard polystyrene. [GPC conditions] Pump: Hitachi L-6000 type (trade name, manufactured by Hitachi, Ltd.) Column: Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (all trade names, manufactured by Resonac Corporation) Eluent: tetrahydrofuran Measurement temperature: 40°C Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI (trade name, manufactured by Hitachi, Ltd.)

[0105] The acid value was measured using the following procedure. First, 1 g of the binder polymer to be measured for acid value was precisely weighed. Next, 30 g of acetone was added to this binder polymer to uniformly dissolve the binder polymer, thereby obtaining a solution. Next, an appropriate amount of phenolphthalein as an indicator was added to this solution, and then titration was performed using a 0.1 N aqueous potassium hydroxide (KOH) solution. The acid value was determined by calculating the mass (unit: mg) of potassium hydroxide required to neutralize the acetone solution of the binder polymer.

[0106] (Binder Polymer A2) A solution of binder polymer A2 was obtained in the same manner as binder polymer A1, except that solution (a) was prepared by mixing 27 parts by mass of methacrylic acid, 50 parts by mass of styrene, 20 parts by mass of benzyl methacrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, and 0.9 parts by mass of azobisisobutyronitrile. The non-volatile content (solid content) of the binder polymer A2 solution was 49% by mass. The weight average molecular weight (Mw) of binder polymer A2 was 35,000, the number average molecular weight (Mn) was 16,000, and the acid value was 176 mgKOH / g.

[0107] <Preparation of Photosensitive Resin Composition> A binder polymer and photopolymerizable compound shown in Table 1, 3.5 parts by mass of a photopolymerization initiator (BCIM: 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, manufactured by Hampford Chemical Industry Co., Ltd.), 0.043 parts by mass of a sensitizer (4,4'-bis(diethylamino)benzophenone, manufactured by Hodogaya Chemical Co., Ltd.), 0.03 parts by mass of 4-tert-butylcatechol (polymerization inhibitor, manufactured by DIC Corporation, trade name "DIC-TBC"), 4-hydroxy-2,2,6,6-tetramethyl A photosensitive resin composition was prepared by mixing 0.01 parts by mass of dimethylpiperidine-N-oxyl (polymerization inhibitor, manufactured by Adeka Corporation, trade name "LA-7RD"), 0.7 parts by mass of leuco crystal violet (manufactured by Yamada Chemical Co., Ltd.), 0.05 parts by mass of malachite green (manufactured by Osaka Organic Chemical Industry Ltd.), and 1.0 part by mass of an adhesion promoter (a mixture of carboxybenzotriazole, 5-amino-1H-tetrazole, and methoxypropanol, manufactured by Sanwa Chemical Co., Ltd., trade name "SF-808H"). The binder polymer was supplied using the binder polymer solution described above. Table 1 shows the blend amounts of the binder polymer and photopolymerizable compound (mass of nonvolatile matter (solid content), unit: parts by mass).

[0108] The following components were used as the photopolymerizable compounds in Table 1. B1: EO-modified bisphenol A dimethacrylate (compound corresponding to component (b), EO groups: 10 (total), molecular weight: 804, manufactured by Resonac Co., Ltd., trade name "FA-321M") B2: EO-modified bisphenol A dimethacrylate (compound not corresponding to component (b), EO groups: 4 (total), manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "BPE-200") B3: (PO)(EO)(PO)-modified dimethacrylate (compound not corresponding to component (b), EO groups: 6 (total), PO groups: 12 (total), molecular weight: 1114, manufactured by Resonac Co., Ltd., trade name "FA-024M")

[0109] <Preparation of Photosensitive Element> A polyethylene terephthalate film (manufactured by Toray Industries, Inc., trade name "FB-40", thickness: 16 μm) was prepared as a support. The above-described photosensitive resin composition was applied to the support so as to have a uniform thickness, and then dried sequentially in a hot air convection dryer at 80°C and 120°C to form a photosensitive layer (film-like photosensitive resin composition, thickness after drying: 25 μm). A polyethylene film (manufactured by Tamapoly Co., Ltd., trade name "NF-15A", thickness: 28 μm) was laminated to this photosensitive layer as a protective layer, thereby obtaining a photosensitive element having a support, a photosensitive layer, and a protective layer in that order.

[0110] <Evaluation> (Hardness of Photosensitive Layer) While peeling off the protective layer, the above-mentioned photosensitive element was laminated at room temperature (25°C) so that the photosensitive layer was in contact with a glass plate, thereby obtaining a laminate having the glass plate, the photosensitive layer, and the support in that order. The lamination was performed using a heat roll at 110°C, at a pressure of 0.4 MPa and a roll speed of 1.0 m / min.

[0111] The hardness of the photosensitive layer was evaluated using an indentation hardness tester (Fischerscope HCV, Model H100SMC, manufactured by Fischer Technology, Inc.) according to the following procedure. First, the tip of a pyramidal jig was brought into contact with the surface of the support of the laminate, and then the jig was pressed in the stacking direction of the laminate with a load of 300 mN for 10 seconds. Next, the maximum load was maintained for 5 seconds, and then the load was released. The indentation depth (unit: μm) at the time when the maximum load was maintained for 5 seconds was obtained as an index of the hardness of the photosensitive layer. The results are shown in Table 1.

[0112] (Followability) A copper-clad laminate (manufactured by Resonac Corporation, product name "MCL-E67") having copper foil (thickness: 35 μm) arranged on both sides of a glass epoxy material was pickled, washed with water, and then dried with an air flow. The copper-clad laminate was then heated to 80°C, and the protective layer was peeled off. The above-mentioned photosensitive element was then laminated onto the copper-clad laminate so that the photosensitive layer was in contact with the copper foil, thereby obtaining a laminate A1 having, in order, a copper-clad laminate, a photosensitive layer, and a support. Lamination was performed using a 110°C heat roll at a pressure of 0.4 MPa and a roll speed of 1.0 m / min.

[0113] A negative mask having a pattern of line width (L) / space width (S) (hereinafter referred to as "L / S") = 100 μm / 100 μm was placed on the support of the above-mentioned laminate A1, and then a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240") using an ultra-high pressure mercury lamp (365 nm) as a light source was used to expose the photosensitive layer through the support at an exposure amount (irradiation energy amount) such that the number of remaining steps of the 41-step tablet after development would be 11, thereby obtaining laminate A2. The exposure amount such that the number of remaining steps of the 41-step tablet after development would be 11 was obtained in advance by placing a 41-step tablet (manufactured by Resonac Corporation) on the support of the above-mentioned laminate A1, and then using a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240") using an ultra-high pressure mercury lamp (365 nm) as a light source, as an exposure amount such that the number of remaining steps of the 41-step tablet after development would be 11.

[0114] Next, the support was peeled off from the laminate A2 to expose the photosensitive layer. Subsequently, the unexposed portions were removed by spraying a 1.0% by mass aqueous solution of sodium carbonate at 30°C for twice the minimum development time, thereby obtaining a resist pattern (exposed portion of the photosensitive layer) with an L / S of 100 μm / 100 μm on the copper-clad laminate. The minimum development time was evaluated in advance using the following procedure. First, the laminate A2 was cut into a rectangular shape (12.5 cm x 4.0 cm), and then the support was peeled off to obtain a test piece. Next, the unexposed photosensitive layer of the test piece was spray-developed using a 1.0% by mass aqueous solution of sodium carbonate at 30°C at a pressure of 0.18 MPa, and the shortest time at which complete removal of the unexposed photosensitive layer could be visually confirmed was determined as the minimum development time.

[0115] After obtaining the resist pattern, the copper foil (copper foil of the copper-clad laminate) exposed from the resist pattern was entirely etched using a copper chloride aqueous solution to obtain two types of laminates A3 with recesses extending in one direction (etching depths) of 3.5 μm and 5.0 μm. The resist pattern of the laminate A3 was then peeled off using a sodium hydroxide aqueous solution to obtain two types of substrates X with recesses of different depths in the areas exposed from the copper foil.

[0116] After heating the above-mentioned substrate X to 80°C, the protective layer was peeled off, and the above-mentioned photosensitive element was laminated from a direction perpendicular to the longitudinal direction of the recess so that the photosensitive layer was in contact with the substrate X, thereby obtaining a laminate B1 having the substrate X, the photosensitive layer, and the support in that order. The lamination was performed using a heat roll at 110°C, at a compression pressure of 0.4 MPa and a roll speed of 1.0 m / min.

[0117] A negative mask having an L / S = 10 μm / 10 μm pattern (a pattern perpendicular to the longitudinal direction of the recesses) was placed on the support of the above-mentioned laminate B1, and then a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240") using an ultra-high pressure mercury lamp (365 nm) as a light source was used to expose the photosensitive layer through the support at an exposure amount (amount of irradiation energy) such that the number of remaining steps of the 41-step tablet after development would be 11, thereby obtaining laminate B2. The exposure amount such that the number of remaining steps of the 41-step tablet after development would be 11 was obtained in advance by placing a 41-step tablet (manufactured by Resonac Corporation) on the support of the above-mentioned laminate B1, and then using a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240") using an ultra-high pressure mercury lamp (365 nm) as a light source, as an exposure amount such that the number of remaining steps of the 41-step tablet after development would be 11.

[0118] Next, the support was peeled off from the laminate B2 to expose the photosensitive layer. Subsequently, the unexposed portions were removed by spraying a 1.0 mass% sodium carbonate aqueous solution at 30°C for twice the minimum development time, thereby obtaining evaluation laminates (two evaluation laminates with recess depths of 3.5 μm and 5.0 μm on the substrate X) having a resist pattern (exposed portions of the photosensitive layer) with an L / S = 10 μm / 10 μm on the substrate X. The minimum development time was evaluated in advance using the following procedure. First, the laminate B2 was cut into a rectangular shape (12.5 cm x 4.0 cm), and then the support was peeled off to obtain test pieces. Next, the unexposed photosensitive layer of the test pieces was spray-developed using a 1.0 mass% sodium carbonate aqueous solution at 30°C at a pressure of 0.18 MPa, and the shortest time at which complete removal of the unexposed photosensitive layer could be visually confirmed was determined as the minimum development time.

[0119] For two types of evaluation laminates with recess depths of 3.5 μm and 5.0 μm in the substrate X, the interface between the substrate X and the resist pattern (L / S = 10 μm / 10 μm) in the evaluation laminate was observed at 160 points using an SEM and a fluorescent microscope to confirm the presence or absence of voids at the interface. If no voids were found in 90% or more of the measurement points, it was judged as "A", if no voids were found in 80% or more but less than 90% of the measurement points, it was judged as "B", and if no voids were found in less than 80% of the measurement points, it was judged as "C". The results are shown in Table 1.

[0120]

[0121] 10...photosensitive element, 12...support, 14...photosensitive layer, 14a...cured product pattern, 16...protective layer, 20...substrate, 22...insulating layer, 24, 24a...conductor layer, 30...plating layer, 40...conductor pattern, L...actinic light.

Claims

1. A photosensitive resin composition containing a binder polymer, a photopolymerizable compound, and a photoinitiator, wherein the photopolymerizable compound includes a polyfunctional monomer having two or more radical-reactive groups and 8 to 16 oxyethylene groups, the content of the polyfunctional monomer is 90% by mass or more based on the total amount of the photopolymerizable compound, and the mass ratio of the binder polymer to the photopolymerizable compound is more than 0 and 1.35 or less.

2. The photosensitive resin composition according to claim 1, wherein the content of the polyfunctional monomer is 96% by mass or more based on the total amount of the photopolymerizable compound.

3. The photosensitive resin composition according to claim 1, wherein the mass ratio of the binder polymer to the photopolymerizable compound is more than 0 and 1.25 or less.

4. The photosensitive resin composition according to claim 1, wherein the molecular weight of the polyfunctional monomer is 600 to 1200.

5. The photosensitive resin composition according to claim 1, wherein the polyfunctional monomer further has a bisphenol A skeleton.

6. The photosensitive resin composition according to claim 1, wherein the binder polymer has a styrene compound and an aryl (meth)acrylate as monomer units.

7. The photosensitive resin composition according to claim 6, wherein the binder polymer further has a hydroxyalkyl (meth)acrylate as a monomer unit.

8. The photosensitive resin composition according to claim 1, further containing a sensitizer.

9. The photosensitive resin composition according to claim 8, wherein the sensitizer includes a dialkylaminobenzophenone compound.

10. A photosensitive element comprising a support and a photosensitive layer disposed on the support, wherein the photosensitive layer contains the photosensitive resin composition according to any one of claims 1 to 9.

11. A cured product of the photosensitive resin composition according to any one of claims 1 to 9.

12. A method for producing a cured product pattern, comprising the steps of forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of claims 1 to 9, photo-curing a part of the photosensitive layer, and removing at least a part of the uncured portion of the photosensitive layer to form a cured product pattern.

13. A method for producing a conductor pattern, comprising the step of forming a conductor pattern using the cured product pattern obtained by the method for producing a cured product pattern according to claim 12 as a mask.

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