Manufacturing method of photosensitive resin composition, photosensitive element and wiring board

Abstract

The photosensitive resin composition disclosed herein contains an adhesive polymer, a photopolymerizable compound, a photopolymerization initiator, and a sensitizer. The adhesive polymer comprises a polymer having styrene compounds and aryl (meth)acrylates as monomer units. The photopolymerizable compound comprises a polyfunctional monomer having two or more reactive groups that react via free radicals and having 8 to 16 oxyethyl groups. The content of the polyfunctional monomer is 96% by mass or more based on the total amount of the photopolymerizable compound.

Description

Photosensitive resin composition, photosensitive element, and method for manufacturing wiring board The present invention discloses a method for manufacturing a photosensitive resin composition, a photosensitive element, and a wiring substrate. When manufacturing a laminate that can be used as a wiring substrate, a resist pattern is formed to obtain the desired wiring. This resist pattern can be formed by exposing and developing a photosensitive resin layer obtained using a photosensitive resin composition. Various photosensitive resin compositions have been studied. For example, Patent Document 1 describes a photosensitive resin composition containing an anthracene derivative. [Patent Document 1] International Publication No. 2007 / 004619 The cured pattern used as a resist pattern is formed, for example, by photocuring (exposing) a photosensitive layer disposed on a substrate and then developing and removing the uncured portion (unexposed portion) of the photosensitive layer. Furthermore, after plating the portion of the substrate where the cured pattern has not been formed, the cured pattern is peeled off (removed) to form a wiring pattern. In order to form a fine wiring layer, it is required to further improve the resolution of the resist pattern. In addition, if the photosensitive layer after photocuring is brittle, damage and defects will occur in the resist pattern during development, which sometimes reduces the yield when forming a fine wiring layer. Therefore, the photosensitive resin composition used to form a fine wiring layer is required to form a resist pattern with excellent resolution and good shape. One object of the present disclosure is to provide a photosensitive resin composition capable of forming a resist pattern having excellent resolution and good shape. Another object of the present disclosure is to provide a method for manufacturing a photosensitive element and a wiring board using the photosensitive resin composition. The present disclosure provides the following photosensitive resin composition, photosensitive element, and method for manufacturing a wiring board. [1] A photosensitive resin composition comprising a binder polymer, a photopolymerizable compound, a photopolymerization initiator, and a sensitizer, wherein the binder polymer comprises a polymer having a styrene compound and a (meth)acrylate as monomer units, and the photopolymerizable compound comprises a multifunctional monomer having two or more reactive groups that react by free radicals and having 8 to 16 oxyethylene groups, wherein the content of the multifunctional monomer is 96% by mass or more based on the total amount of the photopolymerizable compound. [2] The photosensitive resin composition as described in [1] above, wherein the molecular weight of the multifunctional monomer is 600 to 1200. [3] The photosensitive resin composition as described in [1] or [2] above, wherein the multifunctional monomer further comprises a bisphenol A skeleton or a ditrimethylolpropane skeleton. [4] The photosensitive resin composition described in any one of [1] to [3] above, wherein the binder polymer further comprises a hydroxyalkyl (meth)acrylate as a monomer unit. [5] The photosensitive resin composition described in any one of [1] to [4] above, wherein the sensitizer comprises a dialkylaminobenzophenone compound or an anthracene compound. [6] A photosensitive element comprising: a support; and a photosensitive layer formed on the support using the photosensitive resin composition described in any one of [1] to [5]. [7] A method for manufacturing a wiring board, comprising: providing a photosensitive layer on a substrate using the photosensitive resin composition described in any one of [1] to [5] above; photocuring a portion of the photosensitive layer; removing an uncured portion of the photosensitive layer to form a resist pattern; and forming a wiring layer on a portion of the substrate where the resist pattern is not formed. [8] A method for manufacturing a wiring board, comprising: providing a photosensitive layer on a substrate using the photosensitive element described in [6] above; photocuring a portion of the photosensitive layer; removing an uncured portion of the photosensitive layer to form a resist pattern; and forming a wiring layer on a portion of the substrate where the resist pattern is not formed. [Effects of the Invention] According to one aspect of the present disclosure, a photosensitive resin composition capable of forming a resist pattern having excellent resolution and good shape can be provided. Another aspect of the present disclosure provides a method for manufacturing a photosensitive element and a wiring board using the photosensitive resin composition. Hereinafter, embodiments of the present disclosure will be described in detail. Below, preferred embodiments of the present disclosure are described in detail with reference to the accompanying figures as needed. In the following embodiments, components (including essential steps, etc.) are not essential unless specifically noted or considered essential in principle. This applies to numerical values ​​and ranges as well, and should not be construed as unreasonably limiting the present disclosure. In this specification, the term "step" encompasses not only independent steps but also those that cannot be clearly distinguished from other steps, as long as the intended function of the step is achieved. When viewed from above, the term "layer" encompasses not only structures formed on the entire surface but also structures formed on a portion of the surface. "Above A" in a numerical range refers to A and a range exceeding A. "Below A" in a numerical range refers to a range less than A. The numerical range represented by "~" indicates a range that includes the numerical values ​​recorded before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges recorded in stages in this specification, the upper limit value or lower limit value of the numerical range of a certain stage can be arbitrarily combined with the upper limit value or lower limit value of the numerical range of another stage. In the numerical ranges recorded in this specification, the upper limit value or lower limit value of the numerical range can be replaced by the value shown in the embodiment. "A or B" only needs to include either A and B, and can also include both. Unless otherwise specified, the materials exemplified in this specification can be used alone or in combination of two or more. In this specification, "(meth)acrylic acid" means at least one of "acrylic acid" and its corresponding "methacrylic acid". The same applies to other similar expressions such as (meth)acrylates. Unless otherwise specified, "alkyl" can be any of linear, branched or cyclic. "(Poly)oxyethylene" refers to an oxyethylene group or a polyoxyethylene group in which two or more ethylene groups are linked by an ether bond. "(Poly)oxypropylene" refers to an oxypropylene group or a polyoxypropylene group in which two or more propylene groups are linked by an ether bond. "EO modified" refers to a compound having a (poly)oxyethylene group. "PO modified" refers to a compound having a (poly)oxypropylene group. "EO·PO modified" refers to a compound having a (poly)oxyethylene group and / or a (poly)oxypropylene group. In this specification, when multiple substances corresponding to each component are present in a composition, the amount of each component in the composition, unless otherwise specified, refers to the total amount of the multiple substances present in the composition. In this specification, "solids" refers to the non-volatile components of a photosensitive resin composition, excluding volatile substances (such as water and solvent). Specifically, "solids" refers to components other than solvent that remain after drying the photosensitive resin composition and do not volatilize, including components that are liquid, syrupy, or waxy at room temperature (25°C). [Photosensitive Resin Composition] The photosensitive resin composition according to this embodiment contains component (A): a binder polymer, component (B): a photopolymerizable compound, component (C): a photopolymerization initiator, and component (D): a sensitizer. Component (A) comprises a polymer (a) having a styrene compound and an aryl (meth)acrylate as monomer units, and component (B) comprises a multifunctional monomer having two or more free radical-reactive groups and 8 to 16 oxyethylene groups, with the content of the multifunctional monomer being 96% by mass or greater based on the total amount of the photopolymerizable compound. The photosensitive resin composition according to this embodiment can be used, for example, as a negative-type photosensitive resin composition. The photosensitive resin composition may further contain component (E): a polymerization inhibitor or other components, as needed. Each component is described below. (Component (A): Binder Polymer) The photosensitive resin composition contains a binder polymer as component (A). Component (A) may have a polymerizable monomer as a monomer unit (structural unit), and can be obtained, for example, by radical polymerization of the polymerizable monomer. From the perspective of forming a resist pattern with excellent resolution, component (A) contains a styrene compound as a monomer unit. Examples of the styrene compound include styrene and styrene derivatives. Examples of styrene derivatives include vinyltoluene and α-methylstyrene. From the perspective of analytical properties, the content of the styrene compound in component (A) can be 35% by mass or more, 40% by mass or more, 42% by mass or more, or 44% by mass or more, based on the total amount of monomer units constituting component (A). From the perspective of developability, the content can be 70% by mass or less, 60% by mass or less, 58% by mass or less, or 55% by mass or less. From these perspectives, the content of the monomer units of the styrene compound can be 35-70% by mass, 40-60% by mass, 42-58% by mass, or 44-55% by mass. From the perspective of forming a resist pattern with excellent resolution, component (A) contains an aryl (meth)acrylate as a monomer unit. Examples of the aryl (meth)acrylate include benzyl (meth)acrylate, phenyl (meth)acrylate, and naphthyl (meth)acrylate. From the perspective of analytical efficiency, the content of the aryl (meth)acrylate monomer units can be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 18% by mass or more, based on the total amount of the monomer units constituting component (A). From the perspective of analytical efficiency, the content of the aryl (meth)acrylate monomer units can be 40% by mass or less, 30% by mass or less, 28% by mass or less, or 25% by mass or less. From these perspectives, the content of the aryl (meth)acrylate monomer units can be 5-40% by mass, 10-30% by mass, 15-28% by mass, or 18-25% by mass. From the perspective of improving alkali development, component (A) may contain (meth)acrylic acid as a monomer unit. The content of (meth)acrylic acid in component (A) may be 10% by mass or more, 15% by mass or more, 20% by mass or more, or 25% by mass or more, or 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, based on the total amount of monomer units constituting component (A). From the perspective of improving alkali development performance, component (A) may contain a hydroxyalkyl (meth)acrylate as a monomer unit. 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. The content of the hydroxyalkyl (meth)acrylate in the component (A) may be 0.5% by mass or more, 1.0% by mass or more, or 1.5% by mass or more, or 20% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total amount of the monomer units constituting the component (A). Component (A) may further contain structural units derived from other monomers in addition to the above-mentioned monomers. Examples of such other monomers include alkyl (meth)acrylates, vinyl alcohol ethers (such as vinyl-n-butyl ether), (meth)acrylonitrile, maleic acid, maleic anhydride, maleic acid monoesters (such as monomethyl maleate, monoethyl maleate, and monoisopropyl maleate), fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid. From the perspective of improving alkali developability and stripping properties, the other monomer is preferably an alkyl (meth)acrylate. The alkyl group of the alkyl (meth)acrylate can be, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, or structural isomers thereof. To further improve stripping properties, the alkyl group can be a C1-4 alkyl group. To ensure optimal development, the acid value of component (A) can be 100 mgKOH / g or higher, 120 mgKOH / g or higher, 140 mgKOH / g or higher, 150 mgKOH / g or higher, or 160 mgKOH / g or higher. To improve the adhesion (developer resistance) of the cured product of the photosensitive resin composition, the acid value can be 250 mgKOH / g or lower, 240 mgKOH / g or lower, 230 mgKOH / g or lower, 200 mgKOH / g or lower, or 190 mgKOH / g or lower. The acid value of component (A) can be adjusted by adjusting the content of the structural units (e.g., structural units derived from (meth)acrylic acid) that constitute component (A). The acid value can be measured by the method described in the Examples. From the perspective of achieving excellent adhesion (developer resistance) of the cured product of the photosensitive resin composition, the weight average molecular weight (Mw) of component (A) may be 10,000 or greater, 20,000 or greater, 25,000 or greater, or 30,000 or greater. From the perspective of enabling better development, the weight average molecular weight (Mw) of component (A) may be 100,000 or less, 80,000 or less, 60,000 or less, 50,000 or less, or 40,000 or less. From the perspective of facilitating shortening the peeling time of the cured portion, the number average molecular weight (Mn) of component (A) may be 5,000 or greater, 10,000 or greater, 12,000 or greater, or 15,000 or greater, and may also be 35,000 or less, 30,000 or less, 25,000 or less, or 22,000 or less. The dispersion degree (Mw / Mn) of the component (A) may be, for example, 1.0 or more, 1.5 or more, or 2.0 or more. From the viewpoint of further improving adhesion and resolvability, it may be 3.0 or less, 2.8 or less, or 2.5 or less. The weight average molecular weight and dispersity can be measured, for example, by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene. More specifically, they can be measured under the conditions described in the Examples. Furthermore, for compounds with low molecular weights that are difficult to measure using the weight average molecular weight determination method described above, the molecular weight can be measured using other methods and the average calculated. From the viewpoint of excellent film formability, the content of component (A) may be 20% by mass or more, 30% by mass or more, or 40% by mass or more based on the total solid content of the photosensitive resin composition. From the viewpoint of further excellent sensitivity and resolving power, the content may be 90% by mass or less, 80% by mass or less, or 65% by mass or less. From the viewpoint of excellent film formability, the content of component (A) relative to 100 parts by mass of the total amount of component (A) and component (B), may be 30 parts by mass or more, 35 parts by mass or more, or 40 parts by mass or more. From the viewpoint of further improving sensitivity and resolvability, the content may be 70 parts by mass or less, 65 parts by mass or less, or 60 parts by mass or less. (Component (B): Photopolymerizable Compound) The photosensitive resin composition contains a photopolymerizable compound as component (B). The photosensitive resin composition according to this embodiment comprises 96% by mass or more of a polyfunctional monomer having 8 to 16 oxyethylene groups and having two or more reactive groups that react via free radicals, based on the total amount of component (B). This allows the formation of a resist pattern with excellent resolution and a good shape free of breakage and defects. To achieve better resolving power, the number of reactive groups in the multifunctional monomer may be 2-6, 2-5, or 2-4. Examples of reactive groups include groups having an ethylenically unsaturated bond, such as a (meth)acryl group. To further suppress damage and defects in the resist pattern, the number of oxyethylene groups in the multifunctional monomer may be 8-14, 8-12, or 10-12. The multifunctional monomer may not have an oxypropylene group. From the viewpoint of improving the toughness of the resist pattern, the molecular weight of the polyfunctional monomer may be 600 to 1200, 700 to 1150, 750 to 1100, or 780 to 1000. To further improve resolvability, the multifunctional monomer may further have a bisphenol A skeleton or a ditrimethylolpropane skeleton. The multifunctional monomer having a bisphenol A skeleton may be a (meth)acrylic compound having a bisphenol A skeleton. The multifunctional monomer having a ditrimethylolpropane skeleton may be a (meth)acrylic compound having a ditrimethylolpropane skeleton. The multifunctional monomer may include at least one of a (meth)acrylic compound having a bisphenol A skeleton and a (meth)acrylic compound having a ditrimethylolpropane skeleton, or may include both. Examples of (meth)acrylic compounds having a bisphenol A skeleton include EO-modified bisphenol A di(meth)acrylate (EO groups: 8 to 16). Examples of (meth)acrylic compounds having a ditrimethylolpropane skeleton include EO-modified ditrimethylolpropane tetra(meth)acrylate (EO groups: 8 to 16). From the perspective of further suppressing damage and defects in the resist pattern, the content of the polyfunctional monomer, based on the total amount of component (B), is preferably 97% by mass or greater, more preferably 98% by mass or greater, and even more preferably 99% by mass or greater, and may be 100% by mass. In other words, component (B) does not necessarily contain a monofunctional monomer. From the viewpoint of further improving sensitivity and resolving power, the content of the polyfunctional monomer may be 30 to 60 parts by mass, 35 to 55 parts by mass, or 40 to 50 parts by mass relative to 100 parts by mass of the total amount of components (A) and (B). (Component (C): Photopolymerization Initiator) The photosensitive resin composition contains a photopolymerization initiator as component (C). Component (C) is not particularly limited as long as it can polymerize component (B), and can be appropriately selected from commonly used photopolymerization initiators. Examples of the component (C) include hexaarylbiimidazole compounds; benzophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholino)phenyl]-1-butanone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, 2-methyl-1-[4-(methylthio)phenyl]-2- Aromatic ketones such as morpholine-propane-1; quinones such as alkyl anthraquinone; benzoin ether compounds such as benzoin alkyl ether; benzoin compounds such as benzoin and alkyl benzoin; benzyl derivatives such as benzyl dimethyl ketal; and phosphine oxide compounds such as bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, bis(2,6-dimethylbenzyl)-2,4,4-trimethyl-pentylphosphine oxide, and (2,4,6-trimethylbenzyl)ethoxyphenylphosphine oxide. From the perspective of easily achieving excellent sensitivity, resolving power, and adhesion, component (C) may include a hexaarylbiimidazole compound. The aryl group in the hexaarylbiimidazole compound may be a phenyl group, for example. The hydrogen atoms bonded to the aryl groups in the hexaarylbiimidazole compound may be substituted with halogen atoms (such as chlorine atoms). The hexaarylbiimidazole compound may be a 2,4,5-triarylimidazole dimer. Examples of 2,4,5-triarylimidazole dimers include 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-bis-(m-methoxyphenyl)imidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer. From the perspective of achieving excellent sensitivity, resolving power, and adhesion, the hexaarylbiimidazole compound is preferably 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, and more preferably 2,2-bis(o-chlorophenyl)-4,5-4',5'-tetraphenyl-1,2'-biimidazole. From the perspective of easily achieving excellent sensitivity, resolving power, and adhesion, the content of the hexaarylbiimidazole compound can be 90% by mass or greater, 95% by mass or greater, or 99% by mass or greater, based on the total amount of component (C). Component (C) may consist solely of the hexaarylbiimidazole compound. The content of component (C) can be 1.0 to 20 parts by mass, 2.0 to 15 parts by mass, 3.0 to 10 parts by mass, or 4.0 to 8.0 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 within this range, both photosensitivity and resolving power can be improved in a well-balanced manner. (Component (D): Sensitizer) The photosensitive resin composition containing the component (D) can effectively utilize the absorption wavelength of the activating light used for exposure. Examples of the component (D) include dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds, coumarin compounds, xanthone compounds, thioxanthone compounds, oxazole compounds, benzoxazole compounds, thiazole compounds, benzothiazole compounds, triazole compounds, stilbene compounds, trioxane compounds, thiophene compounds, naphthalene dicarboximide compounds, triarylamine compounds, and aminoacridine compounds. Examples of the dialkylaminobenzophenone compound include 4,4′-bis(diethylamino)benzophenone and 4-methoxy-4′-dimethylaminobenzophenone. Examples of the pyrazoline compound include 1-phenyl-3-(4-methoxyphenyl)-5-(4-methoxyphenyl)pyrazoline, 1-phenyl-3-(4-tert-butylphenyl)-5-(4-tert-butylphenyl)pyrazoline, and 1-phenyl-3-biphenyl-5-(4-tert-butylphenyl)pyrazoline. Examples of the coumarin compound include 3-benzyl-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]quinolin-11-one. Examples of the anthracene compound include 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-dibutoxyanthracene, and 9,10-dipentyloxyanthracene. To further improve resolution, component (D) may include a dialkylaminobenzophenone compound or an anthracene compound. To further improve resolution and adhesion, component (D) preferably includes 9,10-diethoxyanthracene, 9,10-propoxyanthracene, or 9,10-dibutoxyanthracene. From the viewpoint of further improving sensitivity, adhesion, and resolvability, the content of component (D) may be 0.01 to 1.5 parts by mass, 0.02 to 1.2 parts by mass, or 0.03 to 1.0 parts by mass relative to 100 parts by mass of the total amount of components (A) and (B). (Component (E): Polymerization Inhibitor) The photosensitive resin composition may further contain component (E): a polymerization inhibitor to inhibit polymerization of unexposed areas during resist pattern formation and further improve resolution. Examples of polymerization inhibitors include 4-tert-butylcatechol and 4-hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl. From the viewpoint of sensitivity and resolvability, the content of component (E) may be 0.001 parts by mass or more, 0.005 parts by mass or more, or 0.01 parts by mass or more relative to 100 parts by mass of the total amount of component (A) and component (B). From the viewpoint of sensitivity and adhesion, the content may be 0.10 parts by mass or less, 0.08 parts by mass or less, or 0.05 parts by mass or less. (Other Components) The photosensitive resin composition may further contain one or more other components in addition to the above-mentioned components. Examples of such other components include hydrogen donors (such as bis[4-(dimethylamino)phenyl]methane, bis[4-(diethylamino)phenyl]methane, and N-phenylglycine), dyes (such as malachite green), tribromophenylsulfonium, photocolorants (such as leuco crystal violet), thermal color inhibitors, plasticizers (such as p-toluenesulfonamide), pigments, fillers, defoamers, flame retardants, stabilizers, adhesion-imparting agents, leveling agents, release accelerators, antioxidants, fragrances, imaging agents, and thermal crosslinking agents. The content of such other components, relative to 100 parts by mass of the total amount of component (A) and component (B), may be 0.005 parts by mass or 0.01 parts by mass, or may be 20 parts by mass or less, or 10 parts by mass or less. From the perspective of adjusting viscosity, the photosensitive resin composition may further contain one or more organic solvents. Examples of organic solvents include methanol, ethanol, acetone, methyl ethyl ketone, methyl cellulose, ethyl cellulose, toluene, N,N-dimethylformamide, and propylene glycol monomethyl ether. The photosensitive resin composition can be prepared as a solution (hereinafter referred to as a "coating solution") having a solids content (non-volatile content) of approximately 30 to 60% by mass by dissolving components (A) to (D) in an organic solvent. The solids content refers to the components remaining after removing volatile components from the photosensitive resin composition solution. The photosensitive resin composition can be used to form a resist pattern, and is particularly preferably used in a method for manufacturing a wiring board to be described later. [Photosensitive Element] The photosensitive element according to this embodiment includes a support and a photosensitive layer formed on the support using the above-mentioned photosensitive resin composition. The photosensitive element may further include a protective layer on the photosensitive layer. Figure 1 is a schematic cross-sectional view of a photosensitive element according to one embodiment. As shown in Figure 1 , the photosensitive element 1 comprises a support 2, a photosensitive layer 3 provided on the support 2, and a protective layer 4 provided on the side of the photosensitive layer 3 opposite to the support 2. The support can be a heat-resistant and solvent-resistant polymer film. Examples of the support include polyester films such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene 2,6-naphthalate (PEN), and polyolefin films such as polyethylene and polypropylene. The haze of the support can be 0.01 to 5.0%, 0.01 to 1.5%, 0.01 to 1.0%, or 0.01 to 0.5%. Haze can be measured using a commercially available haze meter (turbidimeter) according to the method specified in JIS K7105. For example, a commercially available turbidimeter such as the NDH-5000 (manufactured by NIPPON DENSHOKU INDUSTRIES Co., Ltd.) can be used to measure haze. From the perspective of preventing damage to the support when peeling the support from the photosensitive layer, the thickness of the support may be 1 μm or more, 5 μm or more, or 10 μm or more. From the perspective of facilitating optimal exposure when exposing through the support, the thickness of the support may be 100 μm or less, 50 μm or less, 30 μm or less, or 20 μm or less. The protective layer may be a heat-resistant and solvent-resistant polymer film. For example, a polyolefin film such as polyethylene film or polypropylene film can be used. In particular, using a polyethylene film as the protective layer can prevent the photosensitive element from being misaligned during winding. Furthermore, static electricity is less likely to be generated when the protective layer is peeled off from the photosensitive layer, thereby preventing damage to the photosensitive layer. From the perspective of preventing damage to the protective layer when laminating the photosensitive layer and the support on the substrate while peeling the protective layer, the thickness of the protective layer may be 1 μm or more, 5 μm or more, 10 μm or more, or 15 μm or more. From the perspective of improving productivity, the thickness may be 100 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. The photosensitive layer is composed of the aforementioned photosensitive resin composition. To facilitate coating and improve productivity, the thickness of the photosensitive layer after drying (after volatilization of the organic solvent if the photosensitive resin composition contains it) can be 1 μm or greater, 5 μm or greater, or 10 μm or greater. To further improve adhesion and resolution, the thickness can be 100 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. The photosensitive element 1 can be obtained, for example, in the following manner. First, a photosensitive layer 3 is formed on a support 2. The photosensitive layer 3 can be formed, for example, by applying a photosensitive resin composition containing an organic solvent to form a coating layer and drying the coating layer. Next, a protective layer 4 is formed on the surface of the photosensitive layer 3 opposite the support 2. The coating layer is formed by a known method such as roll coating, comma coating, gravure coating, air knife coating, die coating, or bar coating. The coating layer is dried so that the amount of organic solvent remaining in the photosensitive layer 3 is, for example, 2% by mass or less. Specifically, the drying is performed at 70 to 150° C. for about 5 to 30 minutes. From the perspective of facilitating coating and improving productivity, the thickness of the photosensitive layer after drying (after volatilization of the organic solvent when the photosensitive resin composition contains it) can be 1 μm or more, 5 μm or more, or 10 μm or more. From the perspective of further improving adhesion and resolving power, the thickness can be 100 μm or less, 50 μm or less, or 40 μm or less. In another embodiment, the photosensitive element may further include other layers such as a buffer layer, an adhesive layer, a light absorbing layer, and a gas barrier layer. The photosensitive element 1 may be in the form of a sheet, or a photosensitive element roll wound in roll form on a core. In the photosensitive element roll, the photosensitive element 1 is preferably wound so that the support 2 faces the outside. The core may be made of, for example, polyethylene, polypropylene, polystyrene, polyvinyl chloride, or acrylonitrile-butadiene-styrene copolymer. To protect the end faces, the photosensitive element roll may be provided with end spacers, or to prevent edge fusion, with moisture-proof end spacers. The photosensitive element may be packaged, for example, with a black sheet having low moisture permeability. The photosensitive element according to the present embodiment can be suitably used for forming a resist pattern, and is particularly suitable for a method of manufacturing a wiring board to be described later. [Resist Pattern Formation Method] The resist pattern formation method according to this embodiment includes: using the aforementioned photosensitive element, disposing a photosensitive layer and a support on a substrate in this order from the substrate side (photosensitive layer formation step); exposing the photosensitive layer to activating light via the support (exposure step); and, after peeling off the support, removing the uncured portion of the photosensitive layer from the substrate (development step). Other steps may be included as needed. A resist pattern is also referred to as a photocured pattern of a photosensitive resin composition or as a relief pattern. (Photosensitive Layer Formation Step) In the photosensitive layer formation step, a photosensitive element is used to form a photosensitive layer on a substrate. The substrate is not particularly limited, but typically, a circuit forming substrate comprising an insulating layer and a conductive layer formed thereon, or a die pad (a lead frame substrate) such as an alloy substrate can be used. As a method for forming a photosensitive layer on a substrate, for example, after removing a protective layer from a photosensitive element, the photosensitive layer of the photosensitive element is pressed against the substrate while being heated. This method can produce a laminate comprising a substrate, a photosensitive layer, and a support in this order. From the viewpoint of adhesion and followability, the photosensitive layer formation step can be carried out under reduced pressure. The heating during the pressure bonding can be carried out at a temperature of 70 to 130°C, and the pressure during the pressure bonding can be 0.1 to 1.0 MPa (1 to 10 kgf / cm 2 ) pressure, and these conditions can be appropriately selected as needed. Furthermore, if the photosensitive layer of the photosensitive element is heated to 70-130°C, preheating the substrate is not necessary. However, preheating the substrate may be performed to further improve adhesion and tracking properties. (Exposure Step) In the exposure step, the photosensitive layer is exposed to activating light through the support. The exposed portion irradiated with the activating light is photocured to form a photocured portion (latent image). As the exposure method, known exposure methods can be applied. For example, there are methods in which activating light is irradiated into an image through a negative or positive mask pattern called an original image (mask exposure method), LDI (Laser Direct Imaging) exposure method, and methods in which activating light is irradiated into an image through a lens onto which an image of a photomask is projected (projection exposure method). Of these, LDI exposure method and projection exposure method are suitable from the perspective of excellent resolving power. Projection exposure method is also called exposure method using activating light with attenuated energy. The light source for the activating light is not particularly limited as long as it is a commonly used, known light source. For example, a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, a gas laser such as an argon laser, a solid-state laser such as a YAG laser, or a semiconductor laser such as a gallium nitride blue-violet laser can be used. Among these, from the perspective of achieving a well-balanced improvement in resolution and alignment, a light source capable of emitting monochromatic i-ray light with an exposure wavelength of 365 nm, a light source capable of emitting monochromatic h-ray light with an exposure wavelength of 405 nm, or a light source capable of emitting activating light with an exposure wavelength of an iHG mixed line can be used. A light source capable of emitting monochromatic i-ray light with an exposure wavelength of 365 nm or monochromatic h-ray light with an exposure wavelength of 405 nm is preferably used. Examples of light sources capable of emitting monochromatic i-ray light with an exposure wavelength of 365 nm include an ultrahigh-pressure mercury lamp. As a light source capable of emitting h-ray monochromatic light having an exposure wavelength of 405 nm, for example, a blue-violet laser diode having a wavelength of 405 nm can be cited. (Post-Exposure Heat Treatment Step) To improve adhesion, the resist pattern formation method according to this embodiment may include a post-exposure bake (PEB) after the exposure step and before the development step. The temperature during PEB can be 50-100°C. A heating device such as a hot plate, a box dryer, or a heated roller can be used as the heating device. (Development Step) In the development step, after the support is peeled off, the uncured portions of the photosensitive layer are removed from the substrate. Through the development step, a resist pattern formed by the photocured portions of the photosensitive layer is formed on the substrate. The development method can be wet or dry, with wet development being preferred. In the case of wet development, a developer corresponding to the photosensitive resin composition can be used, and development can be carried out by a known wet development method. Examples of wet development methods include dipping, immersion, high-pressure spraying, brushing, scrubbing, and shaking immersion. These wet development methods can be used alone or in combination of two or more. The developer can be appropriately selected according to the composition of the photosensitive resin composition. Examples of the developer include alkaline aqueous solutions and organic solvent developers. From the perspective of safety, stability, and good operability, an alkaline aqueous solution may also be used as a developer. Examples of the base in the alkaline aqueous solution include 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 pyrrolinates such as sodium pyrrolinate and potassium pyrrolinate, sodium borate, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1,3-diaminopropanol-2, morpholine, and the like. Examples of alkaline aqueous solutions include a diluted solution of 0.1-5% by mass sodium carbonate, a diluted solution of 0.1-5% by mass potassium carbonate, a diluted solution of 0.1-5% by mass sodium hydroxide, and a diluted solution of 0.1-5% by mass sodium tetraborate. The pH of the alkaline aqueous solution used for development can be set within the range of 9-11, and the temperature of the alkaline aqueous solution can be adjusted according to the developability of the photosensitive layer. Furthermore, the alkaline aqueous solution may contain, for example, a surfactant to promote development, a defoaming agent, or a small amount of an organic solvent. Examples of the organic solvent used in the alkaline aqueous solution include 3-acetone alcohol, 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 fire, water is added to these organic solvents to provide a concentration of 1 to 20% by mass to prepare the organic solvent developer. (Other Steps) The resist pattern forming method according to the present embodiment may further include the following steps: after removing the uncured portion in the development step, heating at 60 to 250° C. or heating at 0.2 to 10 J / cm 2 The resist pattern is further cured by exposing the resist pattern to an exposure amount of . [Manufacturing method of a wiring substrate] The manufacturing method of a wiring substrate involved in this embodiment includes: a step of providing a photosensitive layer on a substrate using the above-mentioned photosensitive resin composition or photosensitive element; a step of photocuring a portion of the photosensitive layer; a step of removing the uncured portion of the photosensitive layer to form a resist pattern; and a step of forming a wiring layer on the portion of the above-mentioned substrate where the resist pattern is not formed. The method for manufacturing a printed wiring board according to this embodiment may include the following steps: forming a conductor pattern by etching or plating a substrate having a resist pattern formed thereon using the resist pattern forming method described above. Other steps, such as a resist pattern removal step, may also be included as needed. The method for manufacturing a printed wiring board according to this embodiment, using the resist pattern forming method based on the photosensitive element described above, is preferably used for forming a conductor pattern. However, the method for forming a conductor pattern by plating is more preferred. Furthermore, a conductor pattern may also be referred to as a circuit. During the etching process, the resist pattern formed on the substrate having the conductive layer is used as a mask, and the conductive layer of the substrate not covered by the resist is removed by etching to form a conductive pattern. The etching method can be appropriately selected depending on the conductor layer to be removed. Examples of etching solutions include cupric chloride solutions, ferric chloride solutions, alkaline etching solutions, and hydrogen peroxide-based etching solutions. Ferric chloride solutions can be used as etching solutions due to their excellent etching factor. During the plating process, a resist pattern formed on a substrate having a conductive layer is used as a mask to plate copper, solder, or other materials onto the conductive layer of the substrate not covered by the resist. After the plating process, the resist is removed by removing the resist pattern (described later), and the conductive layer covered by the resist is then etched to form a conductive pattern. The plating method may be electrolytic plating or electroless plating. Examples include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-polish solder plating, nickel plating such as Watt bath (nickel sulfate-nickel chloride) plating and nickel sulfamate plating, and gold plating such as hard gold plating and soft gold plating. After the etching or plating process, the resist pattern on the substrate is removed. The resist pattern can be removed, for example, by stripping with an aqueous solution that is more alkaline than the alkaline aqueous solution used in the development step. Examples of such strongly alkaline aqueous solutions include 1-10% by mass sodium hydroxide aqueous solutions and 1-10% by mass potassium hydroxide aqueous solutions. Of these, 1-5% by mass sodium hydroxide aqueous solutions or potassium hydroxide aqueous solutions can be used. Examples of methods for removing the resist pattern include a dipping method and a spraying method, which may be used alone or in combination. After plating, the resist pattern is removed. The resist-coated conductor layer is then etched to form a conductor pattern, thereby producing the desired printed wiring board. The etching method can be appropriately selected depending on the conductor layer to be removed. For example, the aforementioned etching solution can be used. The method for manufacturing a printed wiring board according to the present embodiment can be applied to the manufacture of not only a single-layer printed wiring board but also a multilayer printed wiring board, and can also be applied to the manufacture of a printed wiring board having a through hole of a small diameter. The method for manufacturing a printed wiring board according to this embodiment can be preferably used for manufacturing a high-density package substrate, in particular, for manufacturing a wiring board using a semi-additive process. FIG. 2 shows an example of a manufacturing process for a wiring board using a semi-additive process. In Figure 2(a), a substrate (circuit-forming substrate) is prepared, in which a conductive layer 40 is formed on an insulating layer 50. The conductive layer 40 is, for example, a copper layer. In Figure 2(b), the photosensitive layer forming step described above forms a photosensitive layer 30 and a support 20 on the conductive layer 40 of the substrate. In Figure 2(c), the exposure step described above irradiates the photosensitive layer 30 with activating light 80 projecting an image of a photomask through the support 20, thereby forming a photocured portion on the photosensitive layer 30. In Figure 2(d), the development step removes the areas formed by the exposure step, excluding the photocured portion, from the substrate, thereby forming a resist pattern 32 on the substrate, which serves as the photocured portion. In FIG2(e), a plating process is performed using the photocured portion, i.e., the resist pattern 32, as a mask, to form a plating layer 60 on the conductive layer 40 of the substrate that is not covered by the resist. The conductive layer 40 and the plating layer 60 may be made of the same material or different materials. If the conductive layer 40 and the plating layer 60 are made of the same material, the conductive layer 40 and the plating layer 60 can be integrated. In Figure 2(f), the photocured portion, or resist pattern 32, is stripped and removed using a strong alkaline aqueous solution. Examples of the strong alkaline aqueous solution include a 1-10% by mass sodium hydroxide aqueous solution or a 1-10% by mass potassium hydroxide aqueous solution. Subsequently, a flash etching process is performed to remove the conductive layer 40 masked by the resist pattern 32, thereby forming a conductive pattern 70 comprising the etched plating layer 62 and the etched conductive layer 42. The etching solution can be appropriately selected depending on the type of conductive layer 40; for example, it can be a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, or a hydrogen peroxide etching solution. While projection exposure is described in Figure 2, mask exposure and LDI exposure can also be used to form the resist pattern 32. Using the photosensitive element of this embodiment enables the fabrication of a wiring substrate having a fine conductive layer (wiring layer). While the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. Hereinafter, the present disclosure will be further specifically described through examples, but the present disclosure is not limited to these examples. (Component (A): Binder Polymer) Solution (a) was prepared by mixing the monomers listed in Table 1 in the amounts (unit: parts by mass) listed in the same table with 0.9 parts by mass of azobisisobutyronitrile. Solution (b) was prepared by dissolving 0.5 parts by mass of azobisisobutyronitrile in 50 parts by mass of a mixture (x) consisting of 30 parts by mass of 1-methoxy-2-propanol and 20 parts by mass of toluene. In a flask equipped with a stirrer, reflux cooler, thermometer, dropping funnel, and nitrogen inlet tube, 500 parts by mass of the mixture (x) (300 parts by mass of 1-methoxy-2-propanol and 200 parts by mass of toluene) was placed. The mixture was stirred while nitrogen was blown into the flask and the temperature was raised to 80°C. Solution (a) was then added dropwise to the mixture in the flask at a constant drop rate over 4 hours, followed by stirring at 80°C for 2 hours. Next, the solution (b) was added dropwise to the solution in the flask at a constant dropwise rate over 10 minutes. The solution in the flask was then stirred at 80°C for 3 hours. The temperature of the solution in the flask was then raised to 95°C over 30 minutes and maintained at 95°C for 2 hours. Stirring was then stopped and the solution was cooled to room temperature (25°C) to obtain solutions of binder polymers A1 to A3. The nonvolatile content (solids content) of the solutions of binder polymers A1 to A3 was 49% by mass. Table 1 shows the weight-average molecular weight (Mw), number-average molecular weight (Mn), and acid value of the binder polymers A1 to A3. Mw and Mn were measured by gel permeation chromatography (GPC) under the following conditions and derived by conversion using a calibration curve based on standard polystyrene. (GPC Conditions) Pump: Hitachi L-6000 (manufactured by Hitachi, Ltd.) Column: Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (manufactured by Showa Denko Materials Co., Ltd.) Eluent: Tetrahydrofuran Measurement temperature: 40°C Flow rate: 2.05 mL / min Detector: Hitachi L-3300 RI (manufactured by Hitachi, Ltd.) The acid value was measured using the following procedure. First, 1 g of the binder polymer (the target substance for the acid value measurement) was accurately weighed. Then, 30 g of acetone was added to the binder polymer and uniformly dissolved to obtain a solution. Next, an appropriate amount of phenolphthalein, an indicator, was added to the solution and titrated using a 0.1 N aqueous KOH (potassium hydroxide) solution. The acid value was determined by calculating the mass (in mg) of KOH required to neutralize the binder polymer acetone solution. [Table 1] The following components were prepared to prepare a photosensitive resin composition. (Component (B): Photopolymerizable compound) B1: EO-modified bisphenol A dimethacrylate (EO groups: 10 (total), molecular weight: 804, manufactured by Showa Denko Materials Co., Ltd., product name: "FA-321M") B2: EO-modified ditrimethylolpropane tetramethacrylate (EO groups: 12 (total), molecular weight: 1050, manufactured by TOHO CHEMICAL INDUSTRY COMPANY, LIMITED) B3: EO-modified bisphenol A dimethacrylate (EO groups: 4 (total), Shin Nakamura Chemical Industry Co., Ltd., product name: "BPE-200") B4: 2,2-bis(4-(methacryloyloxypolyethoxy)phenyl)propane (EO groups: 2.6 (total), manufactured by KYOEISHA CHEMICAL Co., Ltd., product name: "BP-2EM") B5: (PO)(EO)(PO) modified dimethacrylate (EO groups: 6 and PO groups: 12 (total), molecular weight: 1114, manufactured by Showa Denko Materials Co., Ltd., product name "FA-024M") (Component (C): Photopolymerization initiator) BCIM: 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole (manufactured by Hampford) (Component (D): Sensitizer) D1: 4,4'-bis(diethylamino)benzophenone (manufactured by HODOGAYA CHEMICAL CO., LTD.) D2: 9,10-dibutoxyanthracene (manufactured by AIR WATER PERFORMANCE CHEMICAL INC., product name "UVS-1331") D3: 9,10-diethoxyanthracene (manufactured by AIR WATER PERFORMANCE CHEMICAL INC., product name "UVS-1101") D4: 9,10-Dipropoxyanthracene (Air Water Performance Chemical Inc., product name "UVS-1221") (Component (E): Polymerization inhibitor) E1: 4-tert-butylcatechol (DIC Corporation, product name "DIC-TBC") E2: 4-Hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl (Adeka Corporation, product name "LA-7RD") (Other ingredients) LCV: Leuco crystal violet (Yamada Chemical Co., Ltd.MKG: Malachite green (manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.) SF-808H: A mixture of carboxybenzotriazole, 5-amino-1H-tetrazole, and methoxypropanol (manufactured by SANWA KASEI CORP.) [Examples 1-3, Comparative Examples 1-2] (Photosensitive Resin Compositions) Photosensitive resin compositions were prepared by mixing the components listed in Table 2 in the amounts (parts by mass) shown in the same table. The amounts (parts by mass) of component (A) shown in Table 2 represent the mass of the non-volatile component (solids content). (Photosensitive Element) A 16μm-thick polyethylene terephthalate film (FS-31, manufactured by TORAY INDUSTRIES, INC.) was prepared as a support. A photosensitive resin composition was applied to the support and then dried in a hot air convection dryer at 80°C and then 120°C, forming a photosensitive layer (thickness after drying: 25μm). A 28μm-thick polyethylene film (NF-15, manufactured by Tamapoly CO., LTD.) was laminated to the photosensitive layer as a protective layer, resulting in a photosensitive element comprising a support, photosensitive layer, and protective layer in that order. Laminated Product: A copper laminate (substrate, SHOWA DENKO MATERIALS CO., LTD., product name "MCL-E67"), consisting of copper foil (35μm thick) applied to both sides of a glass epoxy material, was acid-washed and washed with water, then air-dried. The copper laminate was then heated to 80°C. A photosensitive element was then laminated onto the copper surface while the protective layer was peeled off, with the photosensitive layer in contact with the copper surface. This resulted in a laminate consisting of the copper laminate, photosensitive layer, and support in this order. Lamination was performed using a heated roller at 110°C, with a pressure of 0.4 MPa and a roller speed of 1.0 m / min. (Sensitivity) After placing a 41-step ladder plate (manufactured by Showa Denko Materials Co., Ltd.) on the support of the laminate, the photosensitive layer was exposed through the support using a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240SM") using an ultra-high pressure mercury lamp (365nm) as a light source, with an exposure dose (irradiation energy) such that the number of steps remaining after development of the 41-step ladder plate was 11. The exposure dose at this time (unit: mJ / cm 2 ) to evaluate sensitivity. The lower the exposure, the better the sensitivity. (Resolution and Adhesion) The photosensitive layer was exposed through the support using a glass chrome-type photographic tool (having a resolution negative with a line width (L) / space width (S) pattern of 3x / x (x: 3 to 20, unit: μm) and an adhesion negative with a line width / space width of x / 3x (x: 3 to 20, unit: μm)). Using an ultra-high pressure mercury lamp (365 nm) as the light source, a projection exposure system (manufactured by Ushio Inc., product name "UX-2240SM") was used. The exposure dose (irradiation energy) was such that the number of remaining steps after development of the 41-step ladder plate was 11. After exposure, the support was peeled from the laminate to expose the photosensitive layer. Unexposed areas were removed by spraying a 1.0 mass% sodium carbonate aqueous solution at 30°C for twice the minimum development time. In a resolution negative film, resolution is evaluated by measuring the minimum width of the space in the resist pattern after development, where the space (unexposed area) is removed without residue and the line (exposed area) is formed without any meandering or defects. A smaller value indicates better resolution. In an adhesive negative film, adhesion is evaluated by measuring the minimum line width in the resist pattern, which allows for residue-free removal of the spaces (unexposed areas) and free formation of lines (exposed areas) without any meandering or defects. A smaller value indicates better adhesion. (Breakage and Defect Rate) After exposing the photosensitive layer using the same procedure as for evaluating resolving power and adhesion, the support was peeled from the laminate to expose the photosensitive layer. Unexposed areas were removed by spraying a 1.0 mass% sodium carbonate aqueous solution at 30°C for twice the minimum development time. After development, five lines each 9 mm long were observed in a resist pattern with an L / S ratio of 10 / 10 μm. The breakage and defect rate was calculated as the ratio of the length (mm) of lines with breakage and defects (breakage, defects, peeling, etc.) to the total line length (45 mm). Lines with no breakage or defects were rated "A," lines with a breakage and defect rate of less than 20% were rated "B," and lines with a breakage and defect rate of 20% or greater were rated "C." [Table 2] [Examples 4-8, Comparative Examples 3-4] (Photosensitive Resin Compositions) Photosensitive resin compositions were prepared by mixing the components listed in Table 3 in the amounts (parts by mass) shown in the same table. The amounts (parts by mass) of component (A) shown in Table 3 represent the mass of the non-volatile component (solids content). (Photosensitive Element and Laminated Body) A photosensitive element and laminated body were produced in the same manner as in Examples 1 to 3, except that the photosensitive resin composition was applied on the support so that the thickness of the photosensitive layer after drying was 15 μm. (Sensitivity) After placing a 41-segment ladder plate (manufactured by SHOWA DENKO MATERIALS CO., LTD.) on the support of the laminate, a direct-drawing exposure system (manufactured by Via Mechanics, Ltd., product name "DE-1UH") using a 405nm wavelength blue-violet laser diode as the light source was used to expose the photosensitive layer through the support at an exposure dose (irradiation energy) such that the number of remaining segments after development of the 41-segment ladder plate was 15. The exposure dose (unit: mJ / cm 2 ) to evaluate sensitivity. The lower the exposure, the better the sensitivity. (Analysis) A 41-segment ladder plate (manufactured by SHOWA DENKO MATERIALS CO., LTD.) was placed on the support of the laminate. Then, a direct-drawing exposure system (manufactured by Via Mechanics, Ltd., product name "DE-1UH") using a 405nm blue-violet laser diode as the light source was used to expose (draw) the photosensitive layer through the support. The pattern was drawn with an L / S ratio of 3x / x (x = 3 to 20, unit: μm, 1μm interval). The exposure amount (irradiation energy) was such that the number of remaining segments after development of the 41-segment ladder plate was 15. After exposure, the support was peeled from the laminate to expose the photosensitive layer. Unexposed areas were removed by spraying a 1.0 mass% sodium carbonate aqueous solution at 30°C for twice the minimum development time. After development, resolution was evaluated based on the minimum space width in the resist pattern where the spaces (unexposed areas) were removed without residue and the lines (exposed areas) were formed without meandering or defects. A smaller value indicates better resolution. (Adhesion) The photosensitive layer was exposed and developed using the same procedures as for the resolution evaluation, except that a pattern with an L / S ratio of x / 3x (x = 1 to 20, unit: μm, 1 μm interval) was used, and unexposed areas were removed. After development, adhesion was evaluated based on the minimum line width in the resist pattern where the spaces (unexposed areas) were removed without residue and the lines (exposed areas) were free of meandering or defects. A smaller value indicates better adhesion. (Breakage and Defect Rate) After exposing the photosensitive layer using the same procedure as for evaluating resolving power and adhesion, the support was peeled from the laminate to expose the photosensitive layer. Unexposed areas were removed by spraying a 1.0 mass% sodium carbonate aqueous solution at 30°C for twice the minimum development time. After development, five lines each 8 mm long were observed in a resist pattern with an L / S ratio of 5 / 5 μm. The breakage and defect rate was calculated as the ratio of the length (mm) of lines with breakage and defects (breakage, defects, peeling, etc.) to the total line length (40 mm). Lines with no breakage or defects were rated "A," lines with a breakage and defect rate of less than 20% were rated "B," and lines with a breakage and defect rate of 20% or greater were rated "C." [Table 3] 1: Photosensitive element 2, 20: Support 3, 30: Photosensitive layer 4: Protective layer 32: Resist pattern 40: Conductive layer 42: Conductive layer after etching 50: Insulating layer 60: Plating layer 62: Plating layer after etching 70: Conductive pattern 80: Activating light Fig. 1 is a schematic cross-sectional view showing a photosensitive element according to one embodiment. Fig. 2 is a schematic diagram showing a method for manufacturing a wiring board according to one embodiment.

Claims

1. A photosensitive resin composition comprising an adhesive polymer, a photopolymerizable compound, a photopolymerization initiator, and a sensitizer, wherein the adhesive polymer comprises a polymer having styrene compounds and aryl (meth)acrylates as monomer units, and the photopolymerizable compound comprises a polyfunctional monomer having two or more reactive groups that react via free radicals and having 8 to 16 oxyethyl groups, wherein the content of the polyfunctional monomer is 96% by mass or more based on the total amount of the photopolymerizable compound.

2. The photosensitive resin composition as described in claim 1, wherein the molecular weight of the aforementioned multifunctional monomer is 600 to 1200.

3. The photosensitive resin composition as claimed in claim 1, wherein the aforementioned multifunctional monomer further has a bisphenol A backbone or a bis(trimethylolpropane) backbone.

4. The photosensitive resin composition as claimed in claim 1, wherein the aforementioned adhesive polymer further comprises (meth)acrylate hydroxyalkyl ester as a monomer unit.

5. The photosensitive resin composition as claimed in claim 1, wherein the aforementioned sensitizer comprises a dialkylaminobenzophenone compound or an anthracene compound.

6. A photosensitive element comprising a support and a photosensitive layer formed on the support using any one of claims 1 to 5.

7. A method for manufacturing a wiring board, comprising: The step of forming a photosensitive layer on a substrate using any one of the photosensitive resin compositions described in claims 1 to 5; The steps include: photocuring a portion of the aforementioned photosensitive layer; removing the uncured portion of the aforementioned photosensitive layer to form a resist pattern; and forming a wiring layer on the portion of the aforementioned substrate where the aforementioned resist pattern is not formed.

8. A method for manufacturing a wiring board, comprising: The steps of forming a photosensitive layer on a substrate using the photosensitive element described in claim 6 include: photocuring a portion of the aforementioned photosensitive layer; removing the uncured portion of the aforementioned photosensitive layer to form a resist pattern; and forming a wiring layer on the portion of the aforementioned substrate where the aforementioned resist pattern is not formed.

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