TWI877430B - Photosensitive resin composition, photosensitive element, method for forming anti-etching agent pattern, and method for manufacturing printed wiring board - Google Patents

Abstract

The photosensitive resin composition disclosed herein contains: a binder polymer, a photopolymerizable compound and a photopolymerization initiator. The binder polymer has: a structural unit (a1) derived from a polymerizable monomer having a carboxyl group, a structural unit (a2) derived from styrene or a styrene derivative, a structural unit (a3) derived from an alkyl (meth)acrylate having an alkyl group with a carbon number of 1 to 3, and a structural unit (a4) derived from an alkyl (meth)acrylate having an alkyl group with a carbon number of 4 to 12.

Description

Photosensitive resin composition, photosensitive element, method for forming anti-etching agent pattern, and method for manufacturing printed wiring board

The present invention relates to a photosensitive resin composition, a photosensitive element, a method for forming an anti-etching agent pattern, and a method for manufacturing a printed wiring board.

In the field of printed wiring board manufacturing, a photosensitive resin composition and a photosensitive element having a layer formed on a support film using the photosensitive resin composition (hereinafter also referred to as a "photosensitive layer") are widely used as an anti-etching agent material used in an etching process or a plating process.

A printed wiring board is manufactured using the above-mentioned photosensitive element, for example, according to the following steps. That is, first, the photosensitive layer of the photosensitive element is pressed onto a circuit forming substrate such as a copper foil laminate. Then, the photosensitive layer is exposed through a mask film or the like to form a photocured portion. At this time, the supporting film is peeled off before or after the exposure. Then, the area other than the photocured portion of the photosensitive layer is removed with a developer to form an anti-etching agent pattern. Then, the anti-etching agent pattern is used as an anti-etching agent, and an etching process or a plating process is performed to form a conductor pattern, and finally the photocured portion (anti-etching agent pattern) of the photosensitive layer is peeled off (removed).

In recent years, with the high density of printed wiring boards and the miniaturization of conductor patterns, the contact area between the circuit forming substrate and the photosensitive layer as an anti-etching agent has become smaller. Therefore, the photosensitive layer is required to have excellent characteristics in etching or plating, and also to have excellent adhesion to the circuit forming substrate and excellent resolution in the formation of the anti-etching agent pattern.

For example, Patent Document 1 discloses a photosensitive resin composition having excellent sensitivity and resolution by using a specific sensitizing dye. Also, Patent Document 2 discloses a photosensitive resin composition having excellent sensitivity and resolution by using a specific alkali-soluble polymer and ethylenic double bonds.

[Patent Document 1] Japanese Patent Publication No. 2009-003177 [Patent Document 2] Japanese Patent Publication No. 2013-061556

When the photosensitive layer of the photosensitive element is pressed onto the circuit forming substrate, if the photosensitive layer has poor tracking performance to the circuit forming substrate, there is a possibility that a fine gap will be generated between the photosensitive layer and the circuit forming substrate, which may affect the formation of the conductor pattern. Therefore, the photosensitive layer is required to have excellent tracking performance to the circuit forming substrate.

The purpose of the present disclosure is to provide a photosensitive resin composition capable of forming a photosensitive layer having excellent followability to a circuit forming substrate, a photosensitive element formed using the photosensitive resin composition, a method for forming an anti-etching agent pattern, and a method for manufacturing a printed wiring board.

The photosensitive resin composition disclosed herein contains: a binder polymer, a photopolymerizable compound and a photopolymerization initiator. The binder polymer has: a structural unit (a1) derived from a polymerizable monomer having a carboxyl group, a structural unit (a2) derived from styrene or a styrene derivative, a structural unit (a3) derived from an alkyl (meth)acrylate having an alkyl group with a carbon number of 1 to 3, and a structural unit (a4) derived from an alkyl (meth)acrylate having an alkyl group with a carbon number of 4 to 12.

The photosensitive element disclosed in the present invention comprises a support and a photosensitive layer formed on the support, wherein the photosensitive layer contains the above-mentioned photosensitive resin composition.

The method for forming an anti-etching agent pattern disclosed herein comprises: a step of forming a photosensitive layer on a substrate using the above-mentioned photosensitive resin composition or photosensitive element, a step of irradiating at least a portion of the photosensitive layer with actinic radiation to form a photocured portion, and a step of removing at least a portion of the un-photocured portion of the photosensitive layer from the above-mentioned substrate.

The method for manufacturing a printed wiring board disclosed in the present invention comprises the following steps: a substrate having an anti-etching pattern formed by the above-mentioned method for forming an anti-etching pattern is subjected to plating treatment or etching treatment to form a conductor pattern. [Effect of the invention]

According to the present disclosure, a photosensitive resin composition capable of forming a photosensitive layer having excellent followability to a circuit forming substrate, a photosensitive element formed using the photosensitive resin composition, a method for forming an anti-etching agent pattern, and a method for manufacturing a printed wiring board can be provided.

The present disclosure is described in detail below. However, the present disclosure is not limited to the following embodiments. In this specification, the term "step" includes not only independent steps, but also steps that cannot be clearly distinguished from other steps as long as the intended effect of the step is achieved. In this specification, the term "layer" includes not only structures of shapes formed on the entire surface, but also structures of shapes formed on a portion of the surface when viewed in a plan view.

In this specification, the numerical range represented by "～" means a range that includes the numerical values recorded before and after "～" as the minimum and maximum values, respectively. Furthermore, within the numerical range recorded step by step in this specification, the upper limit or lower limit of the numerical range at any stage can also be replaced by the upper limit or lower limit of the numerical range at other stages. Within the numerical range recorded in this specification, the upper limit or lower limit of the numerical range can also be replaced by the value shown in the embodiments. In this specification, when the amount of each component in a composition is mentioned, and when there are multiple substances equivalent to each component in the composition, unless otherwise specified, it refers to the total amount of the multiple substances present in the composition.

In this specification, "(meth)acrylic acid" means at least one of "acrylic acid" and its corresponding "methacrylic acid", and the same applies to other similar expressions such as (meth)acrylate. In this specification, "solid components" refer to non-volatile components after removing volatile substances such as water and solvent contained in the photosensitive resin composition, and refer to components that are not volatilized and remain when the resin composition is dried, and also include components that are liquid, starch syrup, and wax at room temperature around 25°C.

[Photosensitive resin composition] The photosensitive resin composition of the present embodiment contains: a binder polymer, a photopolymerizable compound and a photopolymerization initiator. The binder polymer has: a structural unit (a1) derived from a polymerizable monomer having a carboxyl group, a structural unit (a2) derived from styrene or a styrene derivative, a structural unit (a3) derived from an alkyl (meth)acrylate having an alkyl group with 1 to 3 carbon atoms, and a structural unit (a4) derived from an alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms. The following is a detailed description of each component used in the photosensitive resin composition of the present embodiment.

(Component (A): Binder polymer) Binder polymer Component (A) of the present embodiment includes a binder polymer having: a structural unit (a1) having a carboxyl group, a structural unit (a2) derived from styrene or a styrene derivative, a structural unit (a3) derived from an alkyl (meth)acrylate having an alkyl group with 1 to 3 carbon atoms, and a structural unit (a4) derived from an alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms.

From the viewpoint of alkali development, the binder polymer has a structural unit (a1). Examples of the polymerizable monomer having a carboxyl group include (meth)acrylic acid, α-bromoacrylic acid, α-chloroacrylic acid, β-furyl (meth)acrylic acid, β-styrene (meth)acrylic acid, maleic acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monoethyl ester, maleic acid monoisopropyl ester and other maleic acid monoesters, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid and propiolic acid. From the viewpoint of further improving alkali development, the polymerizable monomer having a carboxyl group may be (meth)acrylic acid or methacrylic acid.

From the perspective of improving the alkali developability and the followability in a balanced manner, the content of the structural unit (a1) may be 10 to 30 mass %, 15 to 28 mass %, or 20 to 26 mass % based on the total amount of the component (A). When the content of the structural unit (a1) is 10 mass % or more, the alkali developability tends to be improved, and when it is 30 mass % or less, the followability tends to be excellent.

From an analytical point of view, the binder polymer has a structural unit (a2). Styrene derivatives are polymerizable compounds in which the hydrogen atom in the α position or the aromatic ring of styrene such as vinyltoluene and α-methylstyrene is substituted.

From the perspective of improving the alkali developability and the followability in a balanced manner, the content of the structural unit (a2) in the component (A) may be 10 to 50 mass %, 12 to 45 mass %, or 14 to 44 mass % based on the total amount of the component (A).

From an analytical point of view, the binder polymer has a structural unit (a3). Examples of the (meth)acrylic acid alkyl ester having an alkyl group having 1 to 3 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate.

From the perspective of improving the alkali developability and the followability in a balanced manner, the content of the structural unit (a3) in the component (A) may be 5 to 70 mass %, 12 to 65 mass %, or 15 to 64 mass % based on the total amount of the component (A). When the content of the structural unit (a3) is 5 mass % or more, the alkali developability tends to be improved, and when it is 70 mass % or less, the followability tends to be excellent.

From the viewpoint of tracking, the binder polymer has a structural unit (a4). The alkyl group having 4 to 12 carbon atoms may be a linear or branched alkyl group. Examples of the alkyl (meth)acrylate having an alkyl group having 4 to 12 carbon atoms include butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate.

From the perspective of improving the alkali developability and the followability in a balanced manner, the content of the structural unit (a4) in the component (A) may be 0.5 to 30 mass %, 0.8 to 25 mass %, or 1 to 22 mass % based on the total amount of the component (A).

The component (A) may further have a structural unit (a5) other than the structural units (a1) to (a4). Examples of polymerizable monomers for introducing the structural unit (a5) include benzyl (meth)acrylate or its derivatives, acrylamides such as diacetone acrylamide, ether compounds of vinyl alcohol such as vinyl n-butyl ether, acrylonitrile, cycloalkyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isoborneol (meth)acrylate, adamantyl (meth)acrylate, dicyclopentyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and (meth)acrylate. Glycidyl acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, isobornyloxyethyl (meth)acrylate, cyclohexyloxyethyl (meth)acrylate, adamantyloxyethyl (meth)acrylate, dicyclopentenyloxypropoxyethyl (meth)acrylate, dicyclopentyloxypropoxyethyl (meth)acrylate, and adamantyloxypropoxyethyl (meth)acrylate. These can be used alone or in any combination of two or more.

From the perspective of improving the developing property, the resolving power and the tracking property in a more balanced manner, the acid value of the component (A) may be 100 mgKOH/g or more, 110 mgKOH/g or more, 120 mgKOH/g or more, or 130 mgKOH/g or more. From the perspective of improving the tracking property of the photosensitive layer, the acid value of the component (A) may be 180 mgKOH/g or less, 170 mgKOH/g or less, 165 mgKOH/g or less, or 160 mgKOH/g or less. The acid value of the binder polymer may be 100 mgKOH/g or more and 180 mgKOH/g or more, 110 mgKOH/g or more and 170 mgKOH/g or more, 120 mgKOH/g or more and 165 mgKOH/g or more, or 130 mgKOH/g or more and 160 mgKOH/g or less.

From the perspective of better developing properties, the weight average molecular weight (Mw) of the component (A) may be 60,000 or less, 56,000 or less, 54,000 or less, or 52,000 or less. From the perspective of better adhesion, the Mw of the component (A) may be 10,000 or more, 15,000 or more, 20,000 or more, or 25,000 or more. The weight average molecular weight of the binder polymer may be 10,000 or more and 60,000 or less, 15,000 or more and 56,000 or less, 20,000 or more and 54,000 or less, or 25,000 or more and 52,000 or less.

From the perspective of better resolution and adhesion, the dispersion degree (weight average molecular weight/number average molecular weight) of component (A) may be 3.0 or less, 2.8 or less, or 2.5 or less. As the dispersion degree decreases, the resolution tends to improve. The weight average molecular weight and number average molecular weight are values measured by gel permeation chromatography (GPC) and converted using standard polystyrene as a standard sample.

From the viewpoint of further improving the tracking property, the glass transition temperature (Tg) of the component (A) may be 80 to 130°C, 85 to 125°C, or 90 to 120°C.

The component (A) can be used alone or in combination of two or more. Examples of the component (A) used in combination of two or more include two or more binder polymers composed of different polymerizable monomers, two or more binder polymers of different Mw, and two or more binder polymers of different dispersities.

The content of component (A) may be 30 to 80 parts by mass, 40 to 75 parts by mass, 50 to 70 parts by mass, or 50 to 60 parts by mass relative to 100 parts by mass of the total amount of components (A) and (B). When the content of component (A) is within this range, the strength of the photocured portion of the photosensitive layer becomes better.

(Component (B): Photopolymerizable compound) Component (B) has at least one ethylenic unsaturated bond and is not particularly limited as long as it is a compound capable of photopolymerization. The ethylenic unsaturated bond is not particularly limited as long as it is capable of photopolymerization. Examples of the ethylenic unsaturated bond include α,β-unsaturated carbonyl groups such as (meth)acryloyl groups.

As the photopolymerizable compound having an α,β-unsaturated carbonyl group, for example, there can be mentioned α,β-unsaturated carboxylic acid esters of polyols, bisphenol type (meth)acrylates, α,β-unsaturated carboxylic acid adducts of compounds containing a glycidyl group, (meth)acrylates having a polyurethane bond, nonylphenoxypolyethyleneoxyacrylate, and alkyl (meth)acrylates.

Examples of the α,β-unsaturated carboxylic acid ester of a polyol include polyethylene glycol di(meth)acrylate having 2 to 14 vinyl groups, polypropylene glycol di(meth)acrylate having 2 to 14 acrylic groups, polyethylene/polypropylene glycol di(meth)acrylate having 2 to 14 vinyl groups and 2 to 14 acrylic groups, trihydroxymethylpropane di(meth)acrylate, trihydroxymethylpropane tri(meth)acrylate, EO-modified trihydroxymethylpropane tri(meth)acrylate, PO-modified trihydroxymethylpropane tri(meth)acrylate, EO, PO-modified trihydroxymethylpropane tri(meth)acrylate, tetrahydroxymethylmethane tri(meth)acrylate, tetrahydroxymethylmethane tetra(meth)acrylate, and a (meth)acrylate compound having a skeleton derived from dipentatriol or neopentatriol. "EO modification" refers to a block structure with ethylene oxide (EO) groups, and "PO modification" refers to a block structure with propylene oxide (PO) groups.

From the viewpoint of improving the softness of the anti-etching agent pattern, the component (B) may contain polyalkylene glycol di(meth)acrylate. The polyalkylene glycol di(meth)acrylate may have at least one of an EO group and a PO group, or may have both an EO group and a PO group. In the polyalkylene glycol di(meth)acrylate having both an EO group and a PO group, the EO group and the PO group may exist continuously in the form of blocks or randomly. In addition, the PO group may be either an oxy-n-propyl group or an oxy-iso-propyl group. In addition, in the (poly)oxy-iso-propyl group, the secondary carbon of the propylene group may be bonded to the oxygen atom, or the primary carbon may be bonded to the oxygen atom.

Examples of commercially available products of polyalkylene glycol di(meth)acrylate include FA-023M (manufactured by Showa Denko Materials Co., Ltd.), FA-024M (manufactured by Showa Denko Materials Co., Ltd.), and NK Ester HEMA-9P (manufactured by Shin-Nakamura Chemical Co., Ltd.).

From the viewpoint of improving the softness of the anti-corrosion agent pattern, the component (B) may contain a (meth)acrylate having a polyurethane bond. Examples of the (meth)acrylate having a polyurethane bond include an addition reaction product of a (meth)acrylic acid monomer having an OH group at the β position and a diisocyanate (isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, 1,6-hexamethylene diisocyanate, etc.), tris((meth)acryloyloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified polyurethane di(meth)acrylate, and EO, PO-modified polyurethane di(meth)acrylate.

Examples of commercially available products of EO-modified polyurethane di(meth)acrylate include "UA-11" and "UA-21EB" (manufactured by Shin-Nakamura Chemical Co., Ltd.). Examples of commercially available products of EO and PO-modified polyurethane di(meth)acrylate include "UA-13" (manufactured by Shin-Nakamura Chemical Co., Ltd.).

From the viewpoint of easily forming a thick film of the anti-etching agent pattern and improving the resolution and adhesion in a more balanced manner, the component (B) may contain a (meth)acrylate compound having a skeleton derived from dipentatriol or neopentatriol. The (meth)acrylate compound having a skeleton derived from dipentatriol or neopentatriol preferably has 4 or more (meth)acryloyl groups, and may also be dipentatriol penta(meth)acrylate or dipentatriol hexa(meth)acrylate.

From the viewpoint of further improving the resolution and the peeling property after curing, the component (B) may contain a bisphenol type (meth)acrylate, or may contain a bisphenol A type (meth)acrylate among the bisphenol type (meth)acrylates. Examples of the bisphenol A type (meth)acrylate include 2,2-bis(4-((meth)acryloxypolyethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloxypolyethoxypolypropoxy)phenyl)propane. Among them, 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane is preferred from the viewpoint of further improving resolution and pattern formation.

As commercially available products, for example, 2,2-bis(4-((meth)acryloxydipropoxy)phenyl)propane includes BPE-200 (Shin-Nakamura Chemical Co., Ltd.), 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane includes BPE-500 (Shin-Nakamura Chemical Co., Ltd.), FA-321M (Showa Denko Materials co., Ltd.), and the like.

As the nonylphenoxy polyethyleneoxy acrylate, for example, nonylphenoxy tetraethyleneoxy acrylate, nonylphenoxy pentaethyleneoxy acrylate, nonylphenoxy hexaethyleneoxy acrylate, nonylphenoxy heptaethyleneoxy acrylate, nonylphenoxy octaethyleneoxy acrylate, nonylphenoxy nonaethyleneoxy acrylate, nonylphenoxy decaethyleneoxy acrylate and nonylphenoxy undecethyleneoxy acrylate can be cited.

The content of the component (B) is preferably 20 to 60 parts by mass, more preferably 30 to 55 parts by mass, and even more preferably 35 to 50 parts by mass relative to 100 parts by mass of the total amount of the components (A) and (B). When the content of the component (B) is within this range, the light sensitivity and coating properties of the photosensitive resin composition are improved in addition to the resolution, adhesion, and anti-corrosion agent generation.

(Component (C): Photopolymerization initiator) Component (C) is not particularly limited as long as it can polymerize component (B), and can be appropriately selected from commonly used photopolymerization initiators. From the perspective of improving pattern formation, photopolymerization initiators that generate free radicals by actinic radiation can be cited, for example, acylphosphine oxide-based, oxime ester-based, aromatic ketone-based, quinone-based, alkylphenone-based, imidazole-based, acridine-based, phenylglycine-based, coumarin-based, and other photopolymerization initiators.

From the perspective of improving sensitivity and resolution in a balanced manner, component (C) may contain an acridine-based photopolymerization initiator, a phenylglycine-based photopolymerization initiator, or an imidazole-based photopolymerization initiator, and preferably contains an acridine-based photopolymerization initiator. Component (C) may be used alone or in combination of two or more.

Examples of the acridine-based photopolymerization initiator include 9-phenylacridine, 9-(p-methylphenyl)acridine, 9-(m-methylphenyl)acridine, 9-(p-chlorophenyl)acridine, 9-(m-chlorophenyl)acridine, 9-aminoacridine, 9-dimethylaminoacridine, 9-diethylaminoacridine, 9-pentylaminoacridine, 1,2-bis(9-acridyl)ethane, 1,4-bis(9-acridyl)butane, 1,6-bis(9-acridyl)hexane, 1,8-bis(9-acridyl)octane ... Bis(9-acridyl)alkanes such as 10-bis(9-acridyl)decane, 1,12-bis(9-acridyl)dodecane, 1,14-bis(9-acridyl)tetradecane, 1,16-bis(9-acridyl)hexadecane, 1,18-bis(9-acridyl)octadecane, 1,20-bis(9-acridyl)eicosane, 1,3-bis(9-acridyl)-2-oxopropane, 1,3-bis(9-acridyl)-2-thiapropane and 1,5-bis(9-acridyl)-3-thiapentane.

Examples of the phenylglycine-based photopolymerization initiator include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine.

Examples of imidazole-based photopolymerization initiators include 2-(o-chlorophenyl)-4,5-diphenylbisimidazole, 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylbisimidazole, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbisimidazole, 2,4,5-tris-(o-chlorophenyl)-diphenylbisimidazole, 2-(o-chlorophenyl)-bis-4,5-(3,4-dimethoxyphenyl)-bisimidazole, and 2,2',5-tris-(o-chlorophenyl)-diphenylbisimidazole. 2’-Bis-(2-fluorophenyl)-4,4’,5,5’-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2’-Bis-(2,3-difluoromethylphenyl)-4,4’,5,5’-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2’-Bis-(2,4-difluorophenyl)-4,4’,5,5’-tetrakis-(3-methoxyphenyl)-biimidazole and 2,2’-Bis-(2,5-difluorophenyl)-4,4’,5,5’-tetrakis-(3-methoxyphenyl)-biimidazole.

The content of component (C) may be 0.1 to 10 parts by mass, 0.2 to 5 parts by mass, 0.4 to 3 parts by mass, or 0.5 to 2 parts by mass relative to 100 parts by mass of the total amount of components (A) and (B). When the content of component (C) is 0.1 parts by mass or more, the photosensitivity, resolution, and adhesion tend to be improved, and when the content is 10 parts by mass or less, the resist pattern formation tends to be better.

(Component (D): sensitizer) The photosensitive resin composition of the present embodiment may also contain a sensitizer having absorption at 340 to 430 nm as component (D). Thereby, the photosensitivity of the photosensitive resin composition is further improved. As sensitizers, for example, dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds, coumarin compounds, oxanthrone compounds, oxazole compounds, benzoxazole compounds, thiazole compounds, benzothiazole compounds, triazole compounds, distilbenes, triazine compounds, thiophene compounds, naphthyl imide compounds and triarylamine compounds can be cited. From the perspective of sensitivity and adhesion, the sensitizer may contain at least one selected from the group consisting of pyrazoline compounds, anthracene compounds, coumarin compounds and triarylamine compounds, or may contain at least one selected from the group consisting of pyrazoline compounds, anthracene compounds and coumarin compounds.

Examples of the pyrazoline compound include 1-phenyl-3-(4-methoxystyrene)-5-(4-methoxyphenyl)pyrazoline, 1-phenyl-3-(4-tert-butylstyrene)-5-(4-tert-butylphenyl)pyrazoline, and 1-phenyl-3-biphenyl-5-(4-tert-butylphenyl)pyrazoline. Examples of the anthracene compound include 9,10-dibutoxyanthracene and 9,10-diphenylanthracene. Examples of the coumarin compound include 3-benzoyl-7-diethylaminocoumarin, 7-diethylamino-4-methylcoumarin, 3,3'-carbonylbis(7-diethylaminocoumarin), and 2,3,6,7-tetrahydro-9-methyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one.

When the photosensitive resin composition contains component (D), the content of component (D) may be 0.01 to 10 mass%, 0.05 to 5 mass%, or 0.1 to 3 mass%, based on the total solid content of the photosensitive resin composition. When the content of component (D) is 0.01 mass% or more, the sensitivity and resolution can be further improved, and when it is 10 mass% or less, the anti-etching agent shape can be suppressed from becoming an inverted shape and the adhesion can be further improved. From the viewpoint of the balance between resolution and adhesion, the content of component (D) may be 0.005 to 0.5 mass parts, 0.008 to 0.2 mass parts, or 0.01 to 0.1 mass parts relative to 100 mass parts of the total amount of components (A) and (B).

(Component (E): Thermal Stabilizer) The photosensitive resin composition of the present embodiment may also contain a thermal stabilizer as the component (E). As the component (E), for example, quinone derivatives such as benzoquinone and hydroquinone, phenol derivatives (hindered phenol derivatives) such as 4-methoxyphenol and 4-(tert-butyl) o-catechol, aminoxyl derivatives such as 2,2,6,6-tetramethylpiperidin-1-oxyl and 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, and hindered amine derivatives such as tetramethylpiperidinyl methacrylate can be cited. Among them, the use of aminoxyl derivatives as the component (E) can make the photosensitive resin composition have good sensitivity and can further improve the resolution and adhesion of the formed anti-etching pattern.

The content of the component (E) may be 0.005 to 10 parts by mass, 0.01 to 8 parts by mass, or 0.01 to 5 parts by mass relative to 100 parts by mass of the total amount of the component (A). When the content of the component (E) is 0.005 parts by mass or more, there is a tendency for better resolution and adhesion, and when it is 10 parts by mass or less, there is a tendency for better sensitivity. The content of the component (E) may be 0.005 to 20 parts by mass, 0.01 to 5 parts by mass, or 0.02 to 1 part by mass relative to 100 parts by mass of the total amount of the components (A) and (B). When the content is 0.005 parts by mass or more, there is a tendency that the resolution and the suppression of the amount of the anti-corrosion agent partial generation are more excellent, and when it is 20 parts by mass or less, there is a tendency that the sensitivity is more excellent.

(Other ingredients) The photosensitive resin composition of this embodiment may contain additives such as dyes, photochromic agents, thermal color inhibitors, plasticizers, pigments, fillers, defoamers, flame retardants, adhesion agents, leveling agents, peeling accelerators, antioxidants, fragrances, developers (imaging agents), thermal crosslinking agents, polymerization inhibitors, etc. as needed. These additives can be used alone or in combination of two or more.

As dyes, for example, malachite green, Victoria blue, brilliant green and methyl violet can be cited. As photochromic agents, for example, tribromophenyl sulfone, colorless crystal violet, diphenylamine, benzylamine, triphenylamine, diethylaniline and o-chloroaniline can be cited. As plasticizers, for example, p-toluenesulfonamide can be cited.

The content of the component (C) may be 0.01 to 10 parts by mass, 0.05 to 5 parts by mass, or 0.1 to 3 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B).

The photosensitive resin composition can be dissolved in a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl thiocyanate, ethyl thiocyanate, toluene, N,N-dimethylformamide, propylene glycol monomethyl ether, or a mixed solvent thereof to prepare a solution having a solid content of about 30 to 60% by mass.

[Photosensitive element] The photosensitive element of this embodiment has a support and a photosensitive layer formed on the support, and the photosensitive layer contains the above-mentioned photosensitive resin composition. When using the photosensitive element of this embodiment, after the photosensitive layer is pressed on the substrate, exposure can be performed without peeling off the support (support film). As shown in the schematic cross-sectional view of one example in FIG. 1, the photosensitive element 1 of this embodiment has a support 2 and a photosensitive layer 3 formed on the support 2 and derived from the above-mentioned photosensitive resin composition, and has other layers such as a protective layer 4 provided as needed.

(Support) As the support, for example, polyester films such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene-2,6-naphthalate (PEN) and polyolefin films such as polypropylene and polyethylene can be cited. Among them, PET film can be used from the viewpoint of easy availability and excellent operability in the manufacturing step (especially heat resistance, heat shrinkage rate, and breaking strength).

The haze of the support body can be 0.01 to 1.0% or 0.01 to 0.5%. If the haze of the support body is 0.01% or more, the support body itself tends to be easy to manufacture, and if it is less than 1.0%, there is a tendency to reduce the small defects that may be generated in the anti-etching agent pattern. "Mist" refers to turbidity. The haze in this disclosure is a value measured based on the method specified in JIS K 7105 and using a commercially available haze meter (turbidimeter). The haze can be measured, for example, by a commercially available turbidimeter such as NDH-5000 (manufactured by NIPPON DENSHOKU INDUSTRIES Co., Ltd.).

The thickness of the support may be 1 to 100 μm, 5 to 60 μm, 10 to 50 μm, 10 to 40 μm, 10 to 30 μm, or 10 to 25 μm. When the thickness of the support is 1 μm or more, there is a tendency to suppress the support from breaking when the support is peeled off. In addition, when the thickness of the support is 100 μm or less, when exposure is performed through the support, a decrease in resolution can be suppressed.

(Protective layer) The photosensitive element may also have a protective layer as needed. As the protective layer, a film in which the bonding force between the photosensitive layer and the protective layer is smaller than the bonding force between the photosensitive layer and the support body may be used, and a low fisheye film may be used. Specifically, for example, a film that can be used as the above-mentioned support body can be cited. From the perspective of the peelability from the photosensitive layer, a polyethylene film can be used as the protective layer. The thickness of the protective layer can be about 1 to 100 μm depending on the application.

The photosensitive element can be manufactured, for example, as follows. That is, a solution of a photosensitive resin composition (coating liquid) is coated on a support to form a coating layer, and the coating layer is dried to form a photosensitive layer. Then, the surface of the photosensitive layer opposite to the support is covered with a protective layer, thereby obtaining a photosensitive element having a support, a photosensitive layer formed on the support, and a protective layer laminated on the photosensitive layer.

The coating liquid can be applied to the support by a known method such as roller coating, comma coating, gravure coating, air knife coating, die coating, or rod coating.

There is no particular limitation on the drying of the coating layer as long as at least a portion of the organic solvent can be removed from the coating layer. For example, it can be dried at 70 to 150°C for about 5 to 30 minutes. From the viewpoint of preventing diffusion of the solvent in the subsequent steps, the amount of residual solvent in the photosensitive layer after drying can be 2% by mass or less.

The thickness of the photosensitive layer in the photosensitive element can be appropriately selected according to the application, but the thickness after drying can be 1 to 100 μm, 1 to 50 μm, or 5 to 40 μm. When the thickness is 1 μm or more, industrial coating becomes easy and productivity is improved. When the thickness is 100 μm or less, adhesion and resolution are improved.

The form of the photosensitive element is not particularly limited. For example, it may be in the form of a sheet or may be rolled up on a core. When rolled up into a roll, it may be rolled up in such a way that the supporting film is on the outside. Examples of the core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

An end face diaphragm may be provided on the end face of the cylindrical photosensitive element to protect the end face, and a moisture-proof end face diaphragm may be provided to prevent edge fusion. The photosensitive element may be packaged in a black sheet with low moisture permeability.

The photosensitive element can be preferably used in the method for forming a resist pattern described below, for example. From the perspective of analytical performance, the photosensitive element is preferably used in a manufacturing method for forming a conductor pattern by etching.

[Method for forming an anti-etching agent pattern] The method for forming an anti-etching agent pattern of the present embodiment comprises: (i) a step of forming a photosensitive layer on a substrate using the above-mentioned photosensitive resin composition or the above-mentioned photosensitive element (photosensitive layer forming step), (ii) a step of irradiating at least a portion (predetermined portion) of the above-mentioned photosensitive layer with actinic radiation to form a photocured portion (exposure step), and (iii) a step of removing at least a portion of the above-mentioned un-photocured portion from the above-mentioned substrate (development step), and may include other steps as needed. In addition, the anti-etching agent pattern is also called a photocured material pattern of the photosensitive resin composition, and is also called a relief pattern. In addition, the method for forming an anti-etching agent pattern is also called a method for manufacturing a substrate with an anti-etching agent pattern.

((i) Photosensitive layer forming step) As a method for forming a photosensitive layer on a substrate, for example, the above-mentioned photosensitive resin composition may be applied and dried, or, after removing the protective layer from the above-mentioned photosensitive element, the photosensitive layer of the photosensitive element may be pressed onto the above-mentioned substrate while being heated. When a photosensitive element is used, a laminated body composed of a substrate, a photosensitive layer and a support body and stacked in sequence can be obtained. The above-mentioned substrate is not particularly limited, but generally, a circuit forming substrate having an insulating layer and a conductive layer formed on the insulating layer or a chip pad such as an alloy substrate (a substrate for a lead frame) can be used.

When using a photosensitive element, it is preferable to perform the photosensitive layer forming step under reduced pressure from the viewpoint of adhesion and tracking. The heating of the photosensitive layer and/or substrate during compression bonding can be performed at a temperature of 70 to 130°C. Compression bonding can be performed at a pressure of about 0.1 to 1.0 MPa (about 1 to 10 kgf/ ^cm2 ), but such conditions can be appropriately selected as needed. In addition, if the photosensitive layer is heated to 70 to 130°C, there is no need to preheat the substrate in advance, but in order to further improve adhesion and tracking, the substrate can also be preheated.

(ii) Exposure step) In the exposure step, at least a portion of the photosensitive layer formed on the substrate is irradiated with actinic radiation, and the portion irradiated with actinic radiation is photocured to form a latent image. At this time, when there is a support on the photosensitive layer, if the support is transparent to actinic radiation, the actinic radiation can be irradiated through the support, but when the support is light-shielding, the photosensitive layer is irradiated with actinic radiation after the support is removed.

As an exposure method, there can be cited a method of irradiating actinic rays in an image-like manner through a negative or positive mask pattern called an original image (mask exposure method). In addition, a method of irradiating actinic rays in an image-like manner by a projection exposure method can also be adopted. In addition, a method of irradiating actinic rays in an image-like manner by a direct drawing exposure method such as an LDI (Laser Direct Imaging) exposure method and a DLP (Digital Light Processing) exposure method can also be adopted.

As the light source of actinic radiation, a known light source can be used, for example, gas lasers such as carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, and argon lasers; solid lasers such as YAG lasers; and semiconductor lasers that effectively radiate ultraviolet rays or visible light can also be used.

(iii) Development step) In the development step, an anti-etching agent pattern is formed on the substrate by removing at least a portion of the uncured portion (other than the photocured portion) of the photosensitive layer from the substrate.

When there is a support on the photosensitive layer, the support is removed and then the area other than the photocured area (also called the unexposed area) is removed (developed). There are two developing methods: wet developing and dry developing, and wet developing is widely used.

In the case of wet development, a developer corresponding to the photosensitive resin composition is used to perform development by a known developing method. As the developing method, there can be cited methods using immersion, rotary immersion, spraying, brushing, patting, brushing, and swing immersion. From the perspective of improving resolution, a high-pressure spray method can also be used as a developing method. It is also possible to combine two or more of these methods for development.

The composition of the developer can be appropriately selected according to the composition of the above-mentioned photosensitive resin composition. As the developer, for example, an alkaline aqueous solution and an organic solvent developer can be cited.

From the viewpoint of safety, stability and good operability, an alkaline aqueous solution may be used as a developer. As the alkali of the alkaline aqueous solution, alkali hydroxides such as lithium, sodium or potassium hydroxides; alkali carbonates such as lithium, sodium, potassium or ammonium carbonates or bicarbonates; alkali metal phosphates such as potassium phosphate and sodium phosphate; alkali metal pyrrolineates such as sodium pyrroline and potassium pyrroline; borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1,3-diaminopropanol-2, morpholine, etc. may be used.

As the alkaline aqueous solution used for development, a 0.1-5 mass% sodium carbonate dilute solution, a 0.1-5 mass% potassium carbonate dilute solution, a 0.1-5 mass% sodium hydroxide dilute solution, a 0.1-5 mass% sodium tetraborate dilute solution, etc. can be used. The pH of the alkaline aqueous solution can be set in the range of 9 to 11, and the temperature can be adjusted according to the alkaline development property of the photosensitive layer. For example, a small amount of an organic solvent for promoting surfactant, defoaming agent, and development can also be mixed in the alkaline aqueous solution.

Examples of the organic solvent used in the alkaline aqueous solution include acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethanol, isopropanol, butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

Examples of organic solvents used in organic solvent developers include 1,1,1-trichloroethane, N-methyl-2-pyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. To prevent ignition, water is added to these organic solvents in an amount of 1 to 20% by mass to prepare the organic solvent developer.

In the method for forming the resist pattern in the present embodiment, after removing the uncured portion in the developing step, a step of further curing the resist pattern by heating at about 60 to 250° C. or exposing at about 0.2 to 10 J/cm ² may be included as needed.

[Manufacturing method of printed wiring board] The manufacturing method of the printed wiring board of this embodiment includes a step of etching or plating a substrate formed with an anti-etching pattern by the above-mentioned anti-etching pattern forming method to form a conductor pattern, and may include other steps such as an anti-etching pattern removal step as needed.

In the plating process, the resist pattern formed on the substrate is used as a mask to plate the conductive layer provided on the substrate. After the plating process, the resist can be removed by removing the resist pattern described later, and then the conductive layer covered by the resist can be etched to form a conductive pattern. The plating process can be electrolytic plating or electroless plating, but electroless plating is preferred.

On the other hand, in the etching process, the resist pattern formed on the substrate is used as a mask to etch away the conductive layer provided on the substrate to form a conductive pattern. The etching process method can be appropriately selected according to the conductive layer to be removed. As etching liquid, for example, copper chloride solution, iron chloride solution, alkaline etching solution and hydrogen peroxide etching liquid can be cited.

After the etching process or the plating process, the resist pattern on the substrate can also be removed. The resist pattern can be removed, for example, by using an aqueous solution that is more alkaline than the alkaline aqueous solution used in the above-mentioned development step. As the strongly alkaline aqueous solution, for example, a 1-10 mass % sodium hydroxide aqueous solution, a 1-10 mass % potassium hydroxide aqueous solution, etc. can be used.

When the resist pattern is removed after the coating treatment, the conductor layer coated with the resist can be further etched by etching to form a conductor pattern, thereby manufacturing a desired printed wiring board. The etching method at this time can be appropriately selected according to the conductor layer to be removed. For example, the above-mentioned etching solution can be applied.

FIG2 shows an example of a manufacturing step based on a subtractive method of a printed wiring board. In FIG2 (a), a substrate (circuit forming substrate) having a conductive layer 40 formed on an insulating layer 50 is prepared. The conductive layer 40 is, for example, a copper layer. In FIG2 (b), a photosensitive layer 30 is formed on the conductive layer 40 by the above-mentioned photosensitive layer forming step. Then, by the above-mentioned exposure step, actinic rays are irradiated on the photosensitive layer 30 by a direct drawing method, thereby forming a photocured portion on the photosensitive layer 30.

In FIG. 2(c), the region other than the photocured portion formed by the exposure step is removed from the substrate by a developing step, thereby forming a resist pattern 32 as a photocured portion on the substrate. In FIG. 2(d), the conductive layer 40 covered by the resist pattern 32 is removed by etching to form a conductive pattern 42. In FIG. 2(e), the resist pattern 32 is stripped by a strong alkaline aqueous solution to produce a substrate having a conductive pattern 42.

The method for manufacturing a printed wiring board of this embodiment can be applied not only to a single-layer printed wiring board, but also to the manufacture of a multi-layer printed wiring board, and can also be applied to the manufacture of a printed wiring board having a small-diameter through hole. [Example]

Hereinafter, the purpose and advantages of this embodiment will be specifically described based on embodiments and comparative examples, but this embodiment is not limited to the following embodiments.

(Binder polymer) Methacrylic acid (MAA), styrene (ST), methyl methacrylate (MMA), butyl methacrylate (BMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA), ethyl acrylate (AEEC) and benzyl methacrylate (BZMA) were prepared as polymerizable monomers for synthesizing the binder polymer used in the examples and comparative examples.

(Binder polymer (A-1)) 25.5 g of methacrylic acid (MAA), 52.9 g of styrene (ST), 9.9 g of methyl methacrylate (MMA), 3.2 g of butyl acrylate (BA), 23.5 g of benzyl methacrylate (BZMA), 0.02 g of 4-methoxyphenol, and 0.7 g of azobisisobutyronitrile were mixed to prepare solution a. Also, 9 g of propylene glycol monomethyl ether, 7.6 g of toluene, and 0.14 g of azobisisobutyronitrile were mixed to prepare solution b. Furthermore, 4.5 g of propylene glycol monomethyl ether, 7.6 g of toluene, and 0.5 g of azobisisobutyronitrile were mixed to prepare solution c.

Into a flask equipped with a stirrer, a reflux cooler, a thermometer, a dropping funnel and a nitrogen inlet tube, 48 g of propylene glycol monomethyl ether and 40 g of toluene were added, and the mixture was stirred at 80°C for 30 minutes while blowing nitrogen into the flask to obtain a mixed liquid.

After the solution a was added dropwise to the mixed solution in the flask over 4 hours, the mixture was stirred at 80°C for 2 hours. Then, the solution b was added dropwise to the solution in the flask, and the mixture was stirred at 80°C for 2 hours. Furthermore, the temperature of the solution in the flask was raised to 95°C over 1 hour while stirring, and the solution c was added dropwise over 10 minutes, and the mixture was stirred at 95°C for 2 hours to react. After the reaction solution was cooled to 50°C, methanol was added to obtain a solution of a binder polymer (A-1). The non-volatile component (solid content) of the binder polymer (A-1) was 47.7% by mass.

(Binder polymers (A-2) to (A-18)) Regarding polymerizable monomers, the materials shown in Table 1 or Table 2 were used at the mass ratios shown in Table 1 or Table 2, and solutions of binder polymers (A-2) to (A-18) were obtained in the same manner as the solution of binder polymer (A-1).

(Weight average molecular weight) 120 mg of the binder polymer solution was taken and dissolved in 5 mL of tetrahydrofuran to prepare a sample for Mw measurement. The Mw was derived by measuring by gel permeation chromatography (GPC) and converting using a calibration curve of standard polystyrene. The GPC conditions are shown below.

(GPC conditions) Pump: Hitachi L-6000 (manufactured by Hitachi, Ltd.) Column: Gelpack GL-R440, Gelpack GL-R450 and Gelpack GL-R440M (manufactured by Showa Denko Materials Co., Ltd., column specifications: 10.7 mm φ × 300 mm) Eluent: Tetrahydrofuran Measurement temperature: 40°C Injection volume: 200 μL Pressure: 49 Kgf/cm ² (4.8 MPa) Flow rate: 2.05 mL/min Detector: Hitachi, Ltd. L-2490 RI (manufactured by Hitachi, Ltd.)

(Acid value) The acid value was measured by the neutralization titration method based on JIS K0070. An appropriate amount of phenolphthalein solution was added as an indicator to a solution prepared by dissolving about 1 g of the binder polymer in a mixed solvent (mass ratio: toluene/methanol = 70/30), and the solution was titrated with a 0.1N potassium hydroxide aqueous solution to measure the acid value of the binder polymer.

(Glass transition temperature) The glass transition temperature (Tg) of the binder polymer was calculated using Fox's formula.

【Table 1】 A-1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 a1 MAA 20.5 twenty two twenty two twenty two twenty two twenty two twenty two 25 twenty two a2 ST 42.9 20 40 40 20 20 15 30 30 a3 MMA 9.9 37 17 twenty two 41 32 62 43 27 a4 BMA - - - 16 17 6 1 2 twenty one BA 3.2 3 3 - - - - - - AEEC - - - - - - - - - EHA - - - - - - - - - a5 BZMA 23.5 18 18 - - 20 - - - Acid value (mgKOH/g) 134 144 144 144 144 144 144 163 144 Tg（℃） 94 100 99 100 100 100 118 118 95 M 30000 30000 50000 50000 30000 50000 35000 45000 45000

【Table 2】 A-10 A-11 A-12 A-13 A-14 A-15 A-16 A-17 A-18 a1 MAA twenty two 25 25 twenty two twenty two 30 30 26 25 a2 ST 30 twenty two 30 30 15 30 30 20 37 a3 MMA 43 44 44 40 62 twenty two twenty two 34 38 a4 BMA - - - - - 8 8 - - BA - - - - - - - - - AEEC - - - - - 10 10 20 EHA 5 9 1 8 1 - - - - a5 BZMA - - - - - - - - - Acid value (mgKOH/g) 144 163 163 144 144 196 196 170 163 Tg（℃） 104 96 118 96 116 96 96 84 120 M 27000 45000 35000 35000 45000 50000 50000 67000 55000

[Photosensitive resin composition] The components (A), (B) and (C) in the blending amounts (parts by mass) shown in Table 3 or Table 4 were mixed with 5 parts by mass of methanol, 10 parts by mass of toluene and 11 parts by mass of acetone as solvents to prepare photosensitive resin compositions of the embodiment and the comparative example, respectively. The blending amounts of the binder polymers shown in Table 3 and Table 4 are the masses of non-volatile components (solid content).

The details of each component shown in Table 3 and Table 4 are as follows. (Component (B): photopolymerizable compound) B-1: FA-321M 2,2-bis(4-(methacryloyloxypentaethoxy)phenyl)propane (Showa Denko Materials Co., Ltd.) B-2: FA-MECH γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-phthalate (Showa Denko Materials co., Ltd.) B-3: M2200 ethoxylated bisphenol A dimethacrylate (modified with an average of 20 mol of EO) (manufactured by Miwon Specialty Chemical Co., Ltd.) B-4: BPE-200 ethoxylated bisphenol A dimethacrylate (modified with an average of 4 mol of EO) (Shin-Nakamura Chemical Co., Ltd.) B-5: SR454 EO-modified trihydroxymethylpropane acrylate (TOMOE ENGINEERING CO.,LTD.) B-6: FA-137M EO modified trihydroxymethyl propane acrylate (Showa Denko Materials co., Ltd.) B-7: DPEA-12 dipentaethrol (meth) acrylate with EO group (Nippon Kayaku Seizo Co.,Ltd.) B-8: UA-21 tri(methacryloyloxytetraethylene glycol isocyanate) hexamethylene isocyanurate (Shin-Nakamura Chemical Co.,Ltd.) B-9: FA-024M EOPO modified dimethacrylate (Showa Denko Materials co.,Ltd.) ((C) component: photopolymerization initiator) C-1: 9-PA 9-phenylacridine (Changzhou Tronly New Electronic Materials CO.,LTD.) C-2: N-PG N-phenylglycine (Changzhou Tronly New Electronic Materials CO.,LTD.） C-3: B-CIM 2,2'-Bis(2-chlorophenyl)-4,4', 5,5'-tetraphenylbiimidazole (HODOGAYA CHEMICAL CO.,LTD.) ((D) component: sensitizer) D-1: DBA 9,10-dibutoxyanthracene (KAWASAKI KASEI CHEMICALS LTD.)

[Photosensitive element] A solution of a photosensitive resin composition was applied to a polyethylene terephthalate (PET) film (Teijin Film Solutions Limited, trade name "G2J") (support) with a thickness of 16μm, and dried in a hot air convection dryer at 75℃ and 125℃ in sequence to form a photosensitive layer with a thickness of 25μm after drying. A polypropylene film (TAMAPOLY CO., LTD., trade name "NF-13") (protective layer) was laminated on the photosensitive layer to obtain a photosensitive element in which a support, a photosensitive layer, and a protective layer were sequentially laminated.

(Followability) The copper surface of the copper foil laminate was etched to produce a substrate with 8 circular holes of 200μm in diameter and 11μm in depth. Then, the substrate was heated to 80°C and the photosensitive element was laminated on the substrate. The protective layer was removed using a 110°C heated roller while the substrate was laminated at a pressure of 0.3MPa and a roller speed of 1.5m/min. In this way, a laminated body was obtained in which the substrate, photosensitive layer and support were laminated in sequence. Using an optical microscope (KEYENCE CORPORATION, VK-8500), the circular hole was observed from directly above the laminate, and the diameter of the air bubble generated between the circular hole of the substrate and the photosensitive layer was measured. The smaller the diameter of the air bubble, the better the tracking performance.

【Table 3】 Embodiment 1 2 3 4 5 6 7 8 9 A-1 53 - - - - - - - A-2 - 53 - - - - - - - A-3 - - 53 - - - - - - A-4 - - - 53 - - - - - A-5 - - - - 53 - - - - A-6 - - - - - 53 - - - A-7 - - - - - - 53 - - A-8 - - - - - - - 53 - A-9 - - - - - - - - 53 B-1 36.8 twenty one twenty one twenty one twenty one twenty one 40 40 38 B-2 6.5 - - - - - - - - B-3 1.3 - - - - - - - - B-4 2.4 - - - - - - - B-5 - 10 10 10 10 10 - - - B-6 - 12 12 12 12 12 5 5 5 B-7 - - - - - - - - - C-1 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 C-2 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 Bubble diameter (μm) 103 107 105 122 114 133 130 125 120

【Table 4】 Embodiment Comparison Example 10 11 12 13 14 15 16 17 1 A-10 53 - - - - - - - - A-11 - 53 - - - - - - - A-12 - - 53 - - - - - - A-13 - - - 53 - - - - - A-14 - - - - 53 - - - - A-15 - - - - - 53 - - - A-16 - - - - - - 53 - - A-17 - - - - - - - 53 - A-18 - - - - - - - - 53 B-1 35 39 39 37 40 39 37 36.8 35 B-2 5 - - - - - - 6.5 - B-3 - - - - - - - 1.3 - B-4 - - - - - 5 - 2.4 - B-5 - - - - - - - - - B-6 - 5 5 5 5 - - - 5 B-7 5 - - - - 5 - - 5 B-8 - - - - - - 5 - - B-9 - - - - - - 5 - - C-1 0.5 0.5 0.5 0.5 0.5 - - 0.5 0.5 C-2 0.03 0.03 0.03 0.03 0.03 - - 0.03 0.03 C-3 - - - - - 3.7 3.7 - - D-1 - - - - - 0.65 0.65 - - Bubble diameter (μm) 108 135 129 113 131 151 156 139 166

It can be seen from Tables 1 to 4 that the photosensitive resin composition containing a binder polymer having a specific structure can form a photosensitive layer with excellent tracking properties.

1: Photosensitive element 2: Support body 3: Photosensitive layer 4: Protective layer

FIG1 is a schematic cross-sectional view showing an embodiment of a photosensitive element. FIG2 is a diagram schematically showing an example of a manufacturing step of a printed wiring board.

Claims (10)

A photosensitive resin composition, which does not include a photosensitive resin composition containing an inorganic black pigment, the photosensitive resin composition contains: a binder polymer, a photopolymerizable compound and a photopolymerization initiator, The aforementioned binder polymer has: a structural unit (a1) derived from a polymerizable monomer having a carboxyl group, a structural unit (a2) derived from styrene or a styrene derivative, a structural unit (a3) derived from an alkyl (meth)acrylate having an alkyl group with a carbon number of 1 to 3, and a structural unit (a4) derived from an alkyl (meth)acrylate having an alkyl group with a carbon number of 4 to 12, Based on the total amount of the aforementioned binder polymer, the content of the aforementioned structural unit (a1) is 10-30% by mass, based on the total amount of the aforementioned binder polymer, the content of the aforementioned structural unit (a2) is 10-50% by mass, based on the total amount of the aforementioned binder polymer, the content of the aforementioned structural unit (a3) is 5-70% by mass, based on the total amount of the aforementioned binder polymer, the content of the aforementioned structural unit (a4) is 0.5-30% by mass, and the photosensitive resin composition is used to form a conductive pattern. The photosensitive resin composition as described in claim 1, wherein the acid value of the aforementioned binder polymer is greater than 100 mgKOH/g and less than 180 mgKOH/g. A photosensitive resin composition as described in claim 1 or claim 2, wherein the weight average molecular weight of the aforementioned binder polymer is greater than 10,000 and less than 60,000. A photosensitive resin composition as described in claim 1 or claim 2, wherein the aforementioned photopolymerization initiator contains an acridine-based photopolymerization initiator. A photosensitive resin composition as described in claim 1 or claim 2, wherein the photopolymerizable compound contains bisphenol di(meth)acrylate. A photosensitive resin composition as described in claim 1 or claim 2, wherein the photopolymerizable compound contains a (meth)acrylate compound having a skeleton derived from dipentatyritol or pentatyritol. A photosensitive element comprising: a support and a photosensitive layer formed on the support, The photosensitive layer contains the photosensitive resin composition described in any one of claim 1 to claim 6. A method for forming an anti-etching agent pattern, comprising: a step of forming a photosensitive layer on a substrate using the photosensitive resin composition described in any one of claim 1 to claim 6 or the photosensitive element described in claim 7; a step of irradiating at least a portion of the photosensitive layer with actinic radiation to form a photocured portion; and a step of removing at least a portion of the un-photocured portion of the photosensitive layer from the substrate. A method for manufacturing a printed wiring board, comprising: A step of forming a conductor pattern by etching or plating a substrate on which an anti-etching pattern is formed by the method for forming an anti-etching pattern described in claim 8. The method for manufacturing a printed wiring board as described in claim 9 further comprises: A step of removing the aforementioned anti-etching agent pattern after the aforementioned etching process or plating process.

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