Photosensitive resin composition, photosensitive element, resist pattern forming method, and printed wiring board manufacturing method

Abstract

The photosensitive resin composition according to the present application contains: a binder polymer, a photopolymerizable compound, and a photopolymerization initiator, the binder polymer having: 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 having 1 to 3 carbon atoms, and a structural unit (a4) derived from an alkyl (meth)acrylate having an alkyl group having 4 to 12 carbon atoms.

Description

Technical Field

[0001] This invention relates to a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for manufacturing a printed circuit board. Background Technology

[0002] In the field of printed circuit board manufacturing, photosensitive resin compositions and photosensitive elements having a layer (hereinafter also referred to as "photosensitive layer") formed on a support film using photosensitive resin compositions are widely used as resist materials in etching or plating processes.

[0003] Printed circuit boards (PCBs) are manufactured using the aforementioned photosensitive element, for example, through the following steps: First, a photosensitive layer of the photosensitive element is laminated onto a circuit-forming substrate such as a copper-clad laminate. Next, the photosensitive layer is exposed through a mask to form a photocurable portion. At this time, a support film is peeled off before or after exposure. Then, the area outside the photocurable portion of the photosensitive layer is removed using a developer to form a resist pattern. Next, the resist pattern is used as a resist for etching or plating to form a conductor pattern. Finally, the photocurable portion (resist pattern) of the photosensitive layer is peeled off (removed).

[0004] In recent years, with the increasing density of printed circuit boards and the miniaturization of conductor patterns, the contact area between the circuit forming substrate and the photosensitive layer, which serves as the resist, has become smaller. Therefore, the photosensitive layer is required to have excellent properties in etching or plating processes, as well as excellent adhesion to the circuit forming substrate and excellent resolution in resist pattern formation.

[0005] For example, Patent Document 1 discloses a photosensitive resin composition with excellent sensitivity and resolution achieved by using specific sensitizing pigments. Furthermore, Patent Document 2 discloses a photosensitive resin composition with excellent sensitivity and resolution achieved by using specific alkali-soluble polymers and vinyl double bonds.

[0006] Previous technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2009-003177

[0009] Patent Document 2: Japanese Patent Application Publication No. 2013-061556 Summary of the Invention

[0010] The technical problem to be solved by the invention

[0011] When a photosensitive layer of a photosensitive element is laminated onto a circuit forming substrate, if the photosensitive layer has poor conformability to the circuit forming substrate, fine gaps may form between the photosensitive layer and the circuit forming substrate, affecting the formation of the conductor pattern. Therefore, the photosensitive layer is required to have excellent conformability to the circuit forming substrate.

[0012] The present invention aims to provide a photosensitive resin composition capable of forming a photosensitive layer with excellent conformability to a circuit forming substrate, a photosensitive element made using the photosensitive resin composition, a method for forming a resist pattern, and a method for manufacturing a printed circuit board.

[0013] means for solving technical problems

[0014] The photosensitive resin composition of the present invention comprises: an adhesive polymer, a photopolymerizable compound, and a photopolymerization initiator. The adhesive 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 1 to 3 carbon atoms, and a structural unit (a4) derived from an alkyl (meth)acrylate having 4 to 12 carbon atoms.

[0015] The photosensitive element of the present invention includes a support and a photosensitive layer formed on the support, the photosensitive layer containing the above-described photosensitive resin composition.

[0016] The method for forming a resist pattern according to the present invention includes: a step of forming a photosensitive layer on a substrate using the above-described photosensitive resin composition or photosensitive element; a step of irradiating at least a portion of the photosensitive layer with photochemical rays to form a photocurable portion; and a step of removing at least a portion of the uncured portion of the photosensitive layer from the substrate.

[0017] The method for manufacturing printed circuit boards according to the present invention includes the following steps: plating or etching a substrate on which a resist pattern has been formed by the above-described resist pattern forming method to form a conductor pattern.

[0018] Invention Effects

[0019] According to the present invention, a photosensitive resin composition capable of forming a photosensitive layer with excellent conformability to a circuit forming substrate can be provided, a photosensitive element made using the photosensitive resin composition, a method for forming a resist pattern, and a method for manufacturing a printed circuit board. Attached Figure Description

[0020] Figure 1 This is a schematic cross-sectional view showing one embodiment of a photosensitive element.

[0021] Figure 2 This is a diagram illustrating one example of the manufacturing process of a printed circuit board. Detailed Implementation

[0022] The present invention will now be described in detail. However, the present invention is not limited to the following embodiments. In this specification, the term "process" includes not only independent processes, but also processes that are difficult to distinguish from other processes, as long as the intended function of the process is achieved. In this specification, the term "layer," when viewed in a plan view, includes not only structures with shapes formed on the entire surface, but also structures with shapes formed on a portion of the surface.

[0023] In this specification, the numerical range indicated by "~" represents the range including the values ​​before and after "~" as the minimum and maximum values, respectively. Furthermore, within the numerical ranges described progressively in this specification, the upper or lower limit of the numerical range at any stage can be replaced with the upper or lower limit of the numerical range at other stages. Within the numerical ranges described in this specification, the upper or lower limit of the numerical range can also be replaced with the values ​​shown in the examples. In this specification, when referring to the amount of each component in the composition, or when multiple substances equivalent to each component are present in the composition, unless otherwise specified, it refers to the total amount of the multiple substances present in the composition.

[0024] In this specification, "(meth)acrylic acid" refers to 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 component" refers to the non-volatile component after removing volatile substances such as water and solvents contained in the photosensitive resin composition. It refers to the component that remains after the resin composition has not been volatilized when it is dried, and also includes components that are liquid, syrupy, or waxy at room temperature (around 25°C).

[0025] [Photosensitive Resin Composition]

[0026] The photosensitive resin composition according to this embodiment contains: an adhesive polymer, a photopolymerizable compound, and a photopolymerization initiator. The adhesive 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 1 to 3 carbon atoms, and a structural unit (a4) derived from an alkyl (meth)acrylate having 4 to 12 carbon atoms. Hereinafter, each component used in the photosensitive resin composition of this embodiment will be described in detail.

[0027] ((A) Composition: Adhesive polymer)

[0028] The component (A) involved in this embodiment includes an adhesive 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 1 to 3 carbon atoms, and a structural unit (a4) derived from an alkyl (meth)acrylate having 4 to 12 carbon atoms.

[0029] From the viewpoint of alkaline developability, the adhesive polymer has a structural unit (a1). Examples of polymerizable monomers with carboxyl groups include (meth)acrylic acid, α-bromoacrylic acid, α-chloroacrylic acid, β-furanyl(meth)acrylic acid, β-styrene(meth)acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinonic acid, itaconic acid, crotonic acid, and propynic acid. From the perspective of further improving alkaline developability, the polymerizable monomer with a carboxyl group can be either (meth)acrylic acid or methacrylic acid.

[0030] From the perspective of balancing the improvement of alkaline developability and followability, based on the total amount of component (A), the content of structural unit (a1) can be 10–30% by mass, 15–28% by mass, or 20–26% by mass. When the content of structural unit (a1) is above 10% by mass, there is a tendency to improve alkaline developability, and when it is below 30% by mass, there is a tendency to have excellent followability.

[0031] From a distinguishing point of view, adhesive polymers have structural units (a2). Styrene derivatives are polymerizable compounds in which hydrogen atoms at the α-position or in the aromatic ring of styrene, such as vinyltoluene and α-methylstyrene, are substituted.

[0032] From the perspective of improving the alkali developability and followability in a balanced way, based on the total amount of component (A), the content of structural unit (a2) in component (A) can be 10-50% by mass, 12-45% by mass, or 14-44% by mass.

[0033] From a distinguishing point of view, the adhesive polymer has a structural unit (a3). Examples of alkyl methacrylates having alkyl groups having 1 to 3 carbon atoms include methyl methacrylate, ethyl methacrylate, and propyl methacrylate.

[0034] From the perspective of balancing the improvement of alkaline developability and followability, based on the total amount of component (A), the content of structural unit (a3) ​​in component (A) can be 5–70% by mass, 12–65% by mass, or 15–64% by mass. When the content of structural unit (a3) ​​is 5% by mass or more, there is a tendency to improve alkaline developability, and when it is below 70% by mass, there is a tendency to have excellent followability.

[0035] From a follower's point of view, the adhesive polymer has structural unit (a4). The alkyl group having 4 to 12 carbon atoms can be a straight-chain or branched alkyl group. Examples of alkyl (meth)acrylates having 4 to 12 carbon atoms include, for example, 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.

[0036] From the perspective of improving the alkali developability and followability in a balanced way, based on the total amount of component (A), the content of structural unit (a4) in component (A) can be 0.5-30% by mass, 0.8-25% by mass, or 1-22% by mass.

[0037] (A) The component may also have a structural unit (a5) in addition to structural units (a1) to (a4). Examples of polymerizable monomers used to introduce structural unit (a5) include, for example, 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, adamantane (meth)acrylate, dicyclopentyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2 2,2-Trifluoroethyl (meth)acrylate, 2,2,3,3-Tetrafluoropropyl (meth)acrylate, dicyclopentenoxyethyl (meth)acrylate, dicyclopentenoxyethyl (meth)acrylate, isocamphenoxyethyl (meth)acrylate, cyclohexyloxyethyl (meth)acrylate, adamantyloxyethyl (meth)acrylate, dicyclopentenoxypropoxyethyl (meth)acrylate, dicyclopentenoxypropoxyethyl (meth)acrylate, and adamantyloxypropoxyethyl (meth)acrylate. These can be used alone or in any combination of two or more.

[0038] To improve developability, resolution, and followability in a more balanced way, the acid value of component (A) can be 100 mg KOH / g or higher, 110 mg KOH / g or higher, 120 mg KOH / g or higher, or 130 mg KOH / g or higher. To further improve the followability of the photosensitive layer, the acid value of component (A) can be 180 mg KOH / g or lower, 170 mg KOH / g or lower, 165 mg KOH / g or lower, or 160 mg KOH / g or lower. The acid value of the adhesive polymer can be 100 mg KOH / g or higher and 180 mg KOH / g or lower, 110 mg KOH / g or higher and 170 mg KOH / g or lower, 120 mg KOH / g or higher and 165 mg KOH / g or higher and 130 mg KOH / g or lower.

[0039] For better developability, the weight-average molecular weight (Mw) of component (A) can be 60,000 or less, 56,000 or less, 54,000 or less, or 52,000 or less. For better adhesion, the Mw of component (A) can 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 adhesive polymer can 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.

[0040] For better resolution and binding, the dispersion (weight-average molecular weight / number-average molecular weight) of component (A) can be below 3.0, 2.8, or 2.5. A smaller dispersion tends to improve resolution. The weight-average molecular weight and number-average molecular weight are values ​​determined by gel permeation chromatography (GPC) and converted using standard polystyrene as the standard sample.

[0041] From the perspective of further improving the scalability, the glass transition temperature (Tg) of (A) can be 80–130℃, 85–125℃ or 90–120℃.

[0042] (A) Component can be used alone or in combination of two or more. Examples of (A) components used in combination of two or more include two or more adhesive polymers composed of different polymerizable monomers, two or more adhesive polymers with different Mw, and two or more adhesive polymers with different dispersities.

[0043] The content of component (A) relative to the total amount of components (A) and (B) 100 parts by mass can be 30-80 parts by mass, 40-75 parts by mass, 50-70 parts by mass, or 50-60 parts by mass. If the content of component (A) is within this range, the strength of the photocured portion of the photosensitive layer becomes better.

[0044] ((B) Component: Photopolymerizable compound)

[0045] As component (B), it has at least one ethylene unsaturated bond, and there are no particular limitations if it is a photopolymerizable compound. The ethylene unsaturated bond is not particularly limited as long as it is photopolymerizable. Examples of ethylene unsaturated bonds include, for example, α,β-unsaturated carbonyl groups such as (meth)acryloyl groups.

[0046] Examples of photopolymerizable compounds having α,β-unsaturated carbonyl groups include, for example, α,β-unsaturated carboxylic acid esters of polyols, bisphenol-type (meth)acrylates, α,β-unsaturated carboxylic acid adducts of compounds containing glycidyl groups, (meth)acrylates having urethane bonds, nonylphenoxy polyethyleneoxy acrylates, and alkyl (meth)acrylates.

[0047] Examples of α,β-unsaturated carboxylic acid esters of polyols include, for example, polyethylene glycol di(meth)acrylate with 2 to 14 vinyl groups, polypropylene glycol di(meth)acrylate with 2 to 14 propylene groups, polyethylene-polypropylene glycol di(meth)acrylate with 2 to 14 vinyl groups and 2 to 14 propylene groups, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, EO,PO-modified trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, and (meth)acrylate compounds having a backbone derived from dipentaerythritol or pentaerythritol. "EO-modified" refers to a block structure having ethylene oxide (EO) groups, and "PO-modified" refers to a block structure having propylene oxide (PO) groups.

[0048] From the viewpoint of improving the flexibility of the resist pattern, component (B) may contain polyalkylene glycol di(meth)acrylate. Polyalkylene glycol di(meth)acrylate may have at least one of EO and PO groups, or both EO and PO groups. In polyalkylene glycol di(meth)acrylate containing both EO and PO groups, the EO and PO groups may exist continuously in a block or random form, respectively. Furthermore, the PO group may be either oxopropylene or oxoisopropylene. Additionally, in the (poly)oxoisopropylene group, the secondary carbon of the propylene group may be bonded to an oxygen atom, or the primary carbon may be bonded to an oxygen atom.

[0049] Commercially available polyalkylene glycol di(meth)acrylates include, for example, FA-023M (manufactured by Showa Denko Materials co., Ltd.), FA-024M (manufactured by Showa Denko Materials co., Ltd.), and NKEster HEMA-9P (manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0050] From the viewpoint of improving the flexibility of the resist pattern, component (B) may contain (meth)acrylates having urethane bonds. Examples of (meth)acrylates having urethane bonds include, for example, addition reactions of (meth)acrylate monomers having an OH group at the β-position with diisocyanates (isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, 1,6-hexamethylene diisocyanate, etc.), tris((meth)acryloyloxytetraethylene glycol isocyanate)hexamethylene isocyanurate, EO-modified urethane di(meth)acrylate, and EO,PO-modified urethane di(meth)acrylate.

[0051] Commercially available EO-modified urethane di(meth)acrylates include, for example, "UA-11" and "UA-21EB" (manufactured by Shin-Nakamura Chemical Co., Ltd.). Commercially available EO and PO-modified urethane di(meth)acrylates include, for example, "UA-13" (manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0052] From the viewpoint of easily forming a thick-film resist pattern and more evenly improving resolution and adhesion, component (B) may contain a (meth)acrylate compound having a backbone derived from dipentaerythritol or pentaerythritol. The (meth)acrylate compound having a backbone derived from dipentaerythritol or pentaerythritol is preferably having four or more (meth)acryloyl groups, and may also be dipentaerythritol penta(meth)acrylate or dipentaerythritol hexa(meth)acrylate.

[0053] From the viewpoint of improving resolution and peeling properties after curing, component (B) may contain bisphenol-type (meth)acrylates, or it may contain bisphenol A-type (meth)acrylates. Examples of bisphenol A-type (meth)acrylates include 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloyloxypolyethoxypolypropoxy)phenyl)propane. Among these, from the viewpoint of improving resolution and pattern-forming properties, 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane is preferred.

[0054] Commercially available products include, for example, 2,2-bis(4-((meth)acryloyloxydipropoxy)phenyl)propane, such as BPE-200 (Shin-Nakamura Chemical Co., Ltd.), 2,2-bis(4-(methacryloyloxypentethoxy)phenyl)propane, such as BPE-500 (Shin-Nakamura Chemical Co., Ltd.), and FA-321M (Showa Denko Materials Co., Ltd.).

[0055] Examples of nonylphenoxy polyethylene oxyacrylates include nonylphenoxy tetraethyleneoxyacrylate, nonylphenoxy pentaethyleneoxyacrylate, nonylphenoxy hexaethyleneoxyacrylate, nonylphenoxy heptaethyleneoxyacrylate, nonylphenoxy octaethyleneoxyacrylate, nonylphenoxy nonaethyleneoxyacrylate, nonylphenoxy decaethyleneoxyacrylate, and nonylphenoxy undecaethyleneoxyacrylate.

[0056] The content of component (B) relative to the total amount of components (A) and (B) 100 parts by mass is preferably set to 20 to 60 parts by mass, more preferably 30 to 55 parts by mass, and even more preferably 35 to 50 parts by mass. If the content of component (B) is within this range, in addition to the resolution, adhesion and resist curling of the photosensitive resin composition, the photosensitivity and coating properties become better.

[0057] (C) Component: Photopolymerization initiator)

[0058] As for component (C), there are no particular restrictions as long as it can polymerize component (B), and it can be appropriately selected from commonly used photopolymerization initiators. From the viewpoint of improving pattern formation, photopolymerization initiators that generate free radicals through photochemical rays can be cited, such as acylphosphine oxides, oxime esters, aromatic ketones, quinones, alkylbenzene ketones, imidazoles, acridines, phenylglycines, coumarins, and other photopolymerization initiators.

[0059] From the perspective of balancing the improvement of sensitivity and resolution, component (C) may contain acridine-based photopolymerization initiators, phenylglycine-based photopolymerization initiators, or imidazole-based photopolymerization initiators, preferably acridine-based photopolymerization initiators. Component (C) can be used alone or in combination of two or more.

[0060] Examples of acridine-based photopolymerization initiators 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, and 1, 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 and other bis(9-acridyl)alkanes, 1,3-bis(9-acridyl)-2-oxopropane, 1,3-bis(9-acridyl)-2-thiapropane and 1,5-bis(9-acridyl)-3-thiapentane.

[0061] Examples of phenylglycine photopolymerization initiators include, for example, N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine.

[0062] Examples of imidazole photopolymerization initiators include 2-(o-chlorophenyl)-4,5-diphenylbiimidazole, 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylbiimidazole, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole, 2,4,5-tris-(o-chlorophenyl)-diphenylbiimidazole, 2-(o-chlorophenyl)-bis-4,5-(3,4-dimethoxyphenyl)-diimidazole, 2, 2'-bis-(2-fluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-bisimidazole, 2,2'-bis-(2,3-difluoromethylphenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-bisimidazole, 2,2'-bis-(2,4-difluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-bisimidazole and 2,2'-bis-(2,5-difluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-bisimidazole.

[0063] The content of component (C) relative to the total amount of components (A) and (B) per 100 parts by mass can be 0.1–10 parts by mass, 0.2–5 parts by mass, 0.4–3 parts by mass, or 0.5–2 parts by mass. When the content of component (C) is 0.1 parts by mass or more, there is a tendency for improved photosensitivity, resolution, and adhesion; when it is less than 10 parts by mass, there is a tendency for better resist pattern formation.

[0064] ((D) Ingredient: Sensitizer)

[0065] The photosensitive resin composition according to this embodiment may further contain a sensitizer having absorption at 340-430 nm as component (D). This further improves the photosensitivity of the photosensitive resin composition. Examples of sensitizers include, for instance, dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds, coumarin compounds, xanthone compounds, oxazole compounds, benzoxazole compounds, thiazole compounds, benzothiazole compounds, triazole compounds, stilbene compounds, triazine compounds, thiophene compounds, naphthimide compounds, and triarylamine compounds. From the viewpoint 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 at least one selected from the group consisting of pyrazoline compounds, anthracene compounds, and coumarin compounds.

[0066] Examples of pyrazoline compounds 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 anthracene compounds include 9,10-dibutoxyanthracene and 9,10-diphenylanthracene. Examples of coumarin compounds 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]benzopyran[6,7,8-ij]quinolizin-11-one.

[0067] When the photosensitive resin composition contains component (D), the content of component (D) can be 0.01–10% by mass, 0.05–5% by mass, or 0.1–3% by mass, based on the total solid content of the photosensitive resin composition. A content of 0.01% by mass or more of component (D) can further improve sensitivity and resolution, while a content of 10% by mass or less can suppress the resist from becoming inverted and improve adhesion. From the viewpoint of balancing resolution and adhesion, the content of component (D) relative to 100 parts by mass of the total amount of components (A) and (B) can be 0.005–0.5 parts by mass, 0.008–0.2 parts by mass, or 0.01–0.1 parts by mass.

[0068] (E) Component: Heat stabilizer)

[0069] The photosensitive resin composition according to this embodiment may also contain a heat stabilizer as component (E). Examples of components (E) include quinone derivatives such as benzoquinone and hydroquinone, phenol derivatives (hindered phenol derivatives) such as 4-methoxyphenol and 4-(tert-butanol), aminooxy derivatives such as 2,2,6,6-tetramethylpiperidin-1-oxy and 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxy, and hindered amine derivatives such as tetramethylpiperidinyl methacrylate. The use of aminooxy derivatives as component (E) allows the photosensitive resin composition to exhibit good sensitivity and further improves the resolution and adhesion of the formed resist pattern.

[0070] The content of component (E) relative to the total amount of component (A) per 100 parts by mass can be 0.005–10 parts by mass, 0.01–8 parts by mass, or 0.01–5 parts by mass. A content of component (E) of 0.005 parts by mass or more tends to result in better resolution and adhesion, while a content of 10 parts by mass or less tends to result in better sensitivity. The content of component (E) relative to the total amount of components (A) and (B) per 100 parts by mass can be 0.005–20 parts by mass, 0.01–5 parts by mass, or 0.02–1 parts by mass. A content of 0.005 parts by mass or more tends to result in better resolution and better suppression of resist curling, while a content of 20 parts by mass or less tends to result in better sensitivity.

[0071] (Other ingredients)

[0072] The photosensitive resin composition involved in this embodiment may also contain, as needed, additives such as dyes, photochromic agents, heat-developing inhibitors, plasticizers, pigments, fillers, defoamers, flame retardants, adhesion promoters, leveling agents, peel accelerators, antioxidants, fragrances, developing agents, thermal crosslinking agents, and polymerization inhibitors. These additives can be used alone or in combination of two or more.

[0073] Examples of dyes include, for example, malachite green, Victoria blue, brilliant green, and methyl violet. Examples of photochromic agents include, for example, tribromophenyl sulfone, colorless crystal violet, diphenylamine, benzylamine, triphenylamine, diethylaniline, and o-chloroaniline. Examples of plasticizers include, for example, p-toluenesulfonamide.

[0074] The content of component (C) relative to the total amount of components (A) and (B) per 100 parts by mass can be 0.01 to 10 parts by mass, 0.05 to 5 parts by mass, or 0.1 to 3 parts by mass.

[0075] The photosensitive resin composition can be dissolved in solvents such as methanol, ethanol, acetone, methyl ethyl ketone, methyl celecoxib, ethyl celecoxib, toluene, N,N-dimethylformamide, propylene glycol monomethyl ether, or mixtures thereof to prepare a solution with a solid content of about 30 to 60% by mass.

[0076] [Photosensitive element]

[0077] The photosensitive element of this embodiment includes a support and a photosensitive layer formed on the support, the photosensitive layer comprising the aforementioned photosensitive resin composition. When using the photosensitive element of this embodiment, after laminating the photosensitive layer onto a substrate, exposure can be performed without peeling off the support (support film). For example, in Figure 1As shown in the schematic cross-sectional view of one example, the photosensitive element 1 according to this embodiment includes a support 2 and a photosensitive layer 3 formed on the support 2 derived from the above-mentioned photosensitive resin composition, and is also provided with other layers such as a protective layer 4 as needed.

[0078] (Support structure)

[0079] Examples of supporting materials include polyester films such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene 2,6-naphthalenedicarboxylate (PEN), as well as polyolefin films such as polypropylene and polyethylene. Among these, PET film is particularly suitable from the viewpoint of being readily available and having excellent operability in the manufacturing process (especially in terms of heat resistance, heat shrinkage rate, and tensile strength).

[0080] The haze of the support can be 0.01–1.0% or 0.01–0.5%. If the haze of the support is 0.01% or higher, there is a tendency to easily manufacture the support itself; if it is 1.0% or lower, there is a tendency to reduce minor defects that may occur in the resist pattern. "Haze" refers to turbidity. The haze in this invention is a value measured using a commercially available haze meter (turbidity meter) based on the method specified in JIS K 7105. The haze can be measured, for example, using a commercially available turbidity meter such as the NDH-5000 (manufactured by NIPPON DENSHOKU INDUSTRIES Co., Ltd.).

[0081] The thickness of the support can be 1–100 μm, 5–60 μm, 10–50 μm, 10–40 μm, 10–30 μm, or 10–25 μm. When the thickness of the support is 1 μm or more, there is a tendency to suppress support breakage during peeling. Furthermore, when the thickness of the support is 100 μm or less, resolution degradation can be suppressed during exposure through the support.

[0082] (protective layer)

[0083] The photosensitive element may also include a protective layer if needed. As a protective layer, a film with a lower adhesion strength between the photosensitive layer and the protective layer than between the photosensitive layer and the support can be used, and a film with low fisheye density can also be used. Specifically, for example, a film suitable for use as the aforementioned support can be cited. From the viewpoint of the self-peelability of the photosensitive layer, a polyethylene film can be used as the protective layer. The thickness of the protective layer can be approximately 1 to 100 μm, depending on the application.

[0084] A photosensitive element can be manufactured, for example, by coating a solution of a photosensitive resin composition (coating liquid) onto a support to form a coating layer, and then drying it to form a photosensitive layer. Next, a protective layer is applied to the side of the photosensitive layer opposite to the support, thereby obtaining a photosensitive element having a support, a photosensitive layer formed on the support, and a protective layer laminated on the photosensitive layer.

[0085] The coating liquid can be applied to the support by known methods such as roller coating, comma coating, gravure coating, air knife coating, die coating, and bar coating.

[0086] There are no particular limitations to drying the coating layer, as long as at least a portion of the organic solvent can be removed from it. For example, it can be dried at 70–150°C for approximately 5–30 minutes. From the viewpoint of preventing solvent diffusion in subsequent processes, the amount of residual solvent in the photosensitive layer after drying can be less than 2% by mass.

[0087] The thickness of the photosensitive layer in a photosensitive element can be appropriately selected according to the application, but the thickness after drying can be 1–100 μm, 1–50 μm, or 5–40 μm. With a thickness of 1 μm or more, industrial coating becomes easier, and productivity is improved. Furthermore, with a thickness of 100 μm or less, adhesion and resolution are improved.

[0088] There are no particular limitations on the shape of the photosensitive element. For example, it can be in sheet form or in a roll wound onto a core. When wound into a roll, it can be wound with the support film on the outside. Examples of plastics that can be used as the core include polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

[0089] To protect the end face of the rolled photosensitive element, an end face diaphragm can be installed; to prevent edge melting, a moisture-proof end face diaphragm can be installed. The photosensitive element can be packaged by wrapping it in a black sheet with low moisture permeability.

[0090] Photosensitive elements can be preferably used, for example, in the method for forming resist patterns described later. From a resolution point of view, this method is suitable for manufacturing methods that form conductor patterns through etching processes.

[0091] [Methods for forming resist patterns]

[0092] The method for forming a resist pattern according to this embodiment includes: (i) a step of forming a photosensitive layer on a substrate using the above-described photosensitive resin composition or the above-described photosensitive element (photosensitive layer formation step); (ii) a step of irradiating at least a portion (a predetermined portion) of the above-described photosensitive layer with photochemical rays to form a photocurable portion (exposure step); and (iii) a step of removing at least a portion of the above-described uncured portion from the above-described substrate (development step), and may include other steps as needed. Furthermore, the resist pattern is also called a photocurable pattern of the photosensitive resin composition, or a relief pattern. And the method for forming the resist pattern is also called a method for manufacturing a substrate with a resist pattern.

[0093] (i) Photosensitive layer formation process)

[0094] As a method for forming a photosensitive layer on a substrate, for example, the aforementioned photosensitive resin composition can be coated and dried, or the photosensitive layer of the photosensitive element can be heated and pressed onto the substrate after the protective layer has been removed from the photosensitive element. When using a photosensitive element, a laminate consisting of a substrate, a photosensitive layer, and a support can be obtained, which are sequentially stacked. There are no particular limitations on the substrate, but generally, a die pad (lead frame substrate) such as a circuit forming substrate or an alloy substrate having an insulating layer and a conductor layer formed on the insulating layer can be used.

[0095] When using photosensitive elements, from the viewpoint of adhesion and tracking, it is preferable to perform the photosensitive layer formation process under reduced pressure. Heating of the photosensitive layer and / or substrate during lamination can be performed at a temperature of 70–130°C. Lamination can be performed at approximately 0.1–1.0 MPa (1–10 kgf / cm²). 2 The pressure can be adjusted to around 70-130°C, but these conditions can be selected as needed. Alternatively, if the photosensitive layer is heated to 70-130°C, preheating of the substrate is not required. However, preheating of the substrate can be performed to further improve adhesion and tracking.

[0096] (ii) Exposure process)

[0097] In the exposure process, at least a portion of the photosensitive layer formed on the substrate is irradiated with photochemical rays, and the irradiated portion is photocured to form a latent image. At this time, if a support is present on the photosensitive layer, and the support is transparent to photochemical rays, the photochemical rays can be irradiated through the support. However, if the support is light-blocking, the photosensitive layer is irradiated with photochemical rays after the support is removed.

[0098] As an exposure method, one example is the method of irradiating photochemical rays in an image-like manner through a negative or positive mask pattern called the original image (mask exposure method). Furthermore, a method of irradiating photochemical rays in an image-like manner using projection exposure method can also be employed. Additionally, a direct depiction exposure method such as LDI (Laser Direct Imaging) exposure method or DLP (Digital Light Processing) exposure method can also be used to irradiate photochemical rays in an image-like manner.

[0099] As a source of photochemical rays, known light sources can be used, such as gas lasers such as carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, and argon lasers; solid-state lasers such as YAG lasers; and semiconductor lasers, which effectively emit ultraviolet and visible light.

[0100] (iii) Developing process)

[0101] In the developing process, a resist 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.

[0102] When a support is present on the photosensitive layer, the area outside the photocurable portion (also known as the unexposed portion) is removed (developed) after the support is removed. Developing methods include wet development and dry development, with wet development being more widely used.

[0103] In wet development, development is performed using a developer solution corresponding to the photosensitive resin composition and a known development method. Examples of development methods include immersion, puddle, spray, brushing, slapping, scrubbing, and agitation immersion. From the viewpoint of improving resolution, high-pressure spraying can also be used as a development method. Two or more of these methods can also be combined for development.

[0104] The composition of the developer can be appropriately selected based on the composition of the above-described photosensitive resin composition. Examples of developers include alkaline aqueous solutions and organic solvent developers.

[0105] From the perspective of safety, stability, and ease of operation, alkaline aqueous solutions can also be used as developers. Alkalis used as alkaline aqueous solutions include hydroxides such as lithium, sodium, or potassium hydroxides; carbonates such as lithium, sodium, potassium, or ammonium carbonates or bicarbonates; alkali metal phosphates such as potassium phosphate and sodium phosphate; alkali metal pyrroline salts such as sodium pyrrolineate and potassium pyrrolineate; borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1,3-diaminopropanol-2, morpholine, etc.

[0106] As an alkaline aqueous solution for development, dilutions of 0.1–5% by mass sodium carbonate, 0.1–5% by mass potassium carbonate, 0.1–5% by mass sodium hydroxide, and 0.1–5% by mass sodium tetraborate can be used. The pH of the alkaline aqueous solution can be set in the range of 9–11, and its temperature can be adjusted according to the alkaline developability of the photosensitive layer. For example, a small amount of organic solvent, such as a surfactant, defoamer, or developer, can also be mixed into the alkaline aqueous solution.

[0107] Examples of organic solvents used in alkaline aqueous solutions include acetone, ethyl acetate, alkoxyethanol having alkoxy groups having 1 to 4 carbon atoms, ethanol, isopropanol, butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

[0108] 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 the range of 1 to 20% by mass to prepare the organic solvent developer.

[0109] In the method for forming the resist pattern in this embodiment, after removing the uncured portions in the developing process, it may also include, as needed, heating to approximately 60–250°C or applying 0.2–10 J / cm² heat. 2 The process of exposing the photoresist pattern to the left and right sides to further cure it.

[0110] [Manufacturing methods for printed circuit boards]

[0111] The method for manufacturing a printed circuit board according to this embodiment includes a step of etching or plating a substrate on which a resist pattern has been formed by the above-described resist pattern forming method to form a conductor pattern, and may include other steps such as a resist pattern removal step as needed.

[0112] In the plating process, a resist pattern formed on the substrate is used as a mask to plate a conductor layer disposed on the substrate. After the plating process, the resist can be removed by removing the resist pattern (described later), and the conductor layer coated with the resist can be further etched to form a conductor pattern. The plating process can be electrolytic plating or electroless plating, but electroless plating is preferred.

[0113] On the other hand, in the etching process, the resist pattern formed on the substrate is used as a mask to etch away the conductor layer disposed on the substrate to form a conductor pattern. The etching method can be appropriately selected depending on the conductor layer to be removed. Examples of etching solutions include copper chloride solution, ferric chloride solution, alkaline etching solution, and hydrogen peroxide-based etching solution.

[0114] The resist pattern on the substrate can also be removed after etching or plating. 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 development process described above. Examples of strongly alkaline aqueous solutions include 1-10% by mass sodium hydroxide aqueous solution and 1-10% by mass potassium hydroxide aqueous solution.

[0115] After the resist pattern is removed following the plating process, the resist-coated conductor layer can be further etched to form a conductor pattern, thereby manufacturing the desired printed circuit 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.

[0116] exist Figure 2 This illustrates an example of a manufacturing process based on the subtractive metnod method for printed circuit boards. Figure 2 In (a), a substrate (circuit forming substrate) on which a conductor layer 40 is formed is prepared. The conductor layer 40 is, for example, a copper layer. Figure 2 In (b), a photosensitive layer 30 is formed on the conductor layer 40 through the above-described photosensitive layer formation process. Next, through the above-described exposure process, photochemical rays are irradiated onto the photosensitive layer 30 using a direct drawing method, thereby forming a photocurable portion on the photosensitive layer 30.

[0117] exist Figure 2 In (c), the area other than the photocurable portion formed by the exposure process described above is removed from the substrate through a developing process, thereby forming a resist pattern 32, which serves as the photocurable portion, on the substrate. Figure 2 In step (d), an etching process is used to remove the conductor layer 40 covered by the resist pattern 32 to form the conductor pattern 42. Figure 2In (e), a substrate with a conductor pattern 42 is fabricated by peeling off the resist pattern 32 with a strong alkaline aqueous solution.

[0118] The printed circuit board manufacturing method described in this embodiment can be applied not only to single-layer printed circuit boards, but also to multi-layer printed circuit boards, and to printed circuit boards with small-diameter through holes.

[0119] Example

[0120] Hereinafter, the purpose and advantages of this embodiment will be specifically described with reference to the embodiments and comparative examples, but this embodiment is not limited to the following embodiments.

[0121] (Adhesive polymer)

[0122] As polymerizable monomers for synthesizing the adhesive polymers used in the examples and comparative examples, 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.

[0123] (Adhesive Polymer (A-1))

[0124] Solution a was prepared by mixing 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. Solution b was prepared by mixing 9 g of propylene glycol monomethyl ether, 7.6 g of toluene, and 0.14 g of azobisisobutyronitrile. Solution c was prepared by mixing 4.5 g of propylene glycol monomethyl ether, 7.6 g of toluene, and 0.5 g of azobisisobutyronitrile.

[0125] A mixture was obtained by adding 48g of propylene glycol monomethyl ether and 40g of toluene to a flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen inlet tube, and stirring at 80°C for 30 minutes while blowing nitrogen into the flask.

[0126] Solution a was added dropwise to the mixture in the flask over a period of 4 hours, and then stirred at 80°C for 2 hours. Next, solution b was added dropwise to the solution in the flask, and the mixture was stirred at 80°C for 2 hours. Furthermore, while continuing to stir, the solution in the flask was heated to 95°C over a period of 1 hour, and then solution c was added dropwise over 10 minutes, with the mixture stirred at 95°C for 2 hours to carry out the reaction. After cooling the reaction solution to 50°C, methanol was added to obtain a solution of the binder polymer (A-1). The non-volatile component (solid component) of the binder polymer (A-1) was 47.7% by mass.

[0127] (Adhesive polymers (A-2) to (A-18))

[0128] Regarding the polymerizable monomers, the materials shown in Table 1 or Table 2 were used at the mass ratios shown in Table 1 or Table 2. Otherwise, solutions of adhesive polymers (A-2) to (A-18) were obtained in the same manner as the solution of adhesive polymer (A-1).

[0129] (weight-average molecular weight)

[0130] A sample for Mw determination was prepared by dissolving 120 mg of the adhesive polymer solution in 5 mL of tetrahydrofuran. The determination was performed by gel permeation chromatography (GPC), and Mw was derived by conversion using a calibration curve of standard polystyrene. The GPC conditions are shown below.

[0131] (GPC conditions)

[0132] Pump: Hitachi L-6000 model (manufactured by Hitachi, Ltd.)

[0133] Gelpack GL-R440, Gelpack GL-R450 and Gelpack GL-R440M (manufactured by Showa Denko Materials Co., Ltd., column specifications:) )

[0134] Eluent: Tetrahydrofuran

[0135] Measurement temperature: 40℃

[0136] Injection volume: 200μL

[0137] Pressure: 49 kgf / cm 2 (4.8MPa)

[0138] Flow rate: 2.05 mL / min

[0139] Detector: Hitachi, Ltd. L-2490 RI (manufactured by Hitachi, Ltd.)

[0140] (Acid value)

[0141] The acid value was determined by neutralization titration based on JIS K0070. The acid value of the adhesive polymer was determined by adding a suitable amount of phenolphthalein solution as an indicator to a solution prepared by dissolving approximately 1 g of the adhesive polymer in a mixed solvent (mass ratio: toluene / methanol = 70 / 30), titrating with a 0.1 N aqueous solution of potassium hydroxide.

[0142] (Glass transition temperature)

[0143] The glass transition temperature (Tg) of the adhesive polymer was calculated using Fox's formula.

[0144] [Table 1]

[0145]

[0146] [Table 2]

[0147]

[0148] [Photosensitive Resin Composition]

[0149] The photosensitive resin compositions of the Examples and Comparative Examples were prepared by mixing components (A), (B), and (C) in the proportions (parts by mass) shown in Table 3 or Table 4 with 5 parts by mass of methanol, 10 parts by mass of toluene, and 11 parts by mass of acetone as solvents. The proportions of the binder polymers shown in Tables 3 and 4 are the mass of the non-volatile components (solid content).

[0150] The detailed information of each component shown in Tables 3 and 4 is as follows.

[0151] ((B) Component: Photopolymerizable compound)

[0152] B-1: FA-321M 2,2-Bis(4-(methacryloyloxypentylethoxy)phenyl)propane (Showa Denko Materials Co., Ltd.)

[0153] B-2: FA-MECH γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl phthalate (Showa Denko Materials co., Ltd.)

[0154] B-3: M2200 ethoxylated bisphenol A dimethacrylate (EO average 20mol modification) (manufactured by Miwon Specialty Chemical Co., Ltd.)

[0155] B-4: BPE-200 ethoxylated bisphenol A dimethacrylate (EO average 4mol modified) (Shin-Nakamura Chemical Co., Ltd.)

[0156] B-5: SR454 EO-modified trimethylolpropane acrylate (TOMOE ENGINEERING CO.,LTD.)

[0157] B-6: FA-137M EO-modified trimethylolpropane acrylate (Showa Denko Materials co., Ltd.)

[0158] B-7: DPEA-12 dipentaerythritol (meth)acrylate with an EO group (Nippon Kayaku Seizo Co., Ltd.)

[0159] B-8: UA-21 Tris(methacryloyloxytetraethylene glycol isocyanate) hexamethylene isocyanurate (Shin-Nakamura Chemical Co., Ltd.)

[0160] B-9: FA-024M EOPO modified dimethacrylate (Showa Denko Materials co., Ltd.)

[0161] (C) Component: Photopolymerization initiator)

[0162] C-1: 9-PA 9-Phenylacetidine (Changzhou Tronly New Electronic Materials CO.,LTD.)

[0163] C-2: N-PG N-phenylglycine (Changzhou Tronly New Electronic Materials CO.,LTD.)

[0164] C-3: B-CIM 2,2'-Bis(2-chlorophenyl)-4,4',5,5'-Tetraphenylbiimidazole (HODOGAYA CHEMICALCO.,LTD.)

[0165] ((D) Ingredient: Sensitizer)

[0166] D-1: DBA 9,10-Dibutoxyanthracene (KAWASAKI KASEI CHEMICALS LTD.)

[0167] [Photosensitive element]

[0168] A solution of the photosensitive resin composition was coated onto a 16 μm thick polyethylene terephthalate (PET) film (Teijin Film Solutions Limited, trade name "G2J") (support), and then dried sequentially using hot air convection dryers at 75°C and 125°C to form a 25 μm thick photosensitive layer. A polypropylene film (TAMAPOLY CO.,LTD., trade name "NF-13") (protective layer) was then laminated onto this photosensitive layer, resulting in a photosensitive element constructed by sequentially stacking the support, photosensitive layer, and protective layer.

[0169] (Following)

[0170] The copper surface of the copper-clad laminate was etched to create a substrate with eight circular holes, each 200 μm in diameter and 11 μm deep. Next, the substrate was heated to 80°C, and a photosensitive element was laminated onto it. Using a heated roller at 110°C, the protective layer was removed while lamination was performed at a pressing pressure of 0.3 MPa and a roller speed of 1.5 m / min. This resulted in a laminate consisting of a substrate, a photosensitive layer, and a support. The diameter of the bubbles generated between the circular holes in the substrate and the photosensitive layer was measured using an optical microscope (KEYENCE CORPORATION, VK-8500) viewed from directly above the laminate. Smaller bubble diameters indicate better tracking performance.

[0171] [Table 3]

[0172]

[0173] [Table 4]

[0174]

[0175] As shown in Tables 1 to 4, photosensitive resin compositions containing adhesive polymers with specific structures can form photosensitive layers with excellent followability.

[0176] Symbol Explanation

[0177] 1-Photosensitive element, 2-Support, 3-Photosensitive layer, 4-Protective layer.

Claims

1. A photosensitive resin composition comprising: an adhesive polymer, a photopolymerizable compound, and a photoinitiator. The adhesive polymer has: structural units derived from polymeric monomers having carboxyl groups (a1), structural units derived from styrene or styrene derivatives (a2), structural units derived from alkyl (meth)acrylates having 1 to 3 carbon atoms (a3), and structural units derived from alkyl (meth)acrylates having 4 to 12 carbon atoms (a4). Based on the total amount of the adhesive polymer, the content of the structural unit (a1) is 10-22% by mass. The adhesive polymer further has structural units derived from benzyl (meth)acrylate. The structural unit (a4) is derived from butyl acrylate.

2. The photosensitive resin composition according to claim 1, wherein, The adhesive polymer has an acid value of 100 mg KOH / g or higher and 180 mg KOH / g or lower.

3. The photosensitive resin composition according to claim 2, wherein, The adhesive polymer has an acid value of 110 mg KOH / g or higher and 170 mg KOH / g or lower.

4. The photosensitive resin composition according to claim 2, wherein, The adhesive polymer has an acid value of 120 mg KOH / g or higher and 165 mg KOH / g or lower.

5. The photosensitive resin composition according to claim 2, wherein, The adhesive polymer has an acid value of 130 mg KOH / g or higher and 160 mg KOH / g or lower.

6. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The weight-average molecular weight of the adhesive polymer is above 10,000 and below 60,000.

7. The photosensitive resin composition according to claim 6, wherein, The weight-average molecular weight of the adhesive polymer is above 25,000.

8. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The glass transition temperature of the adhesive polymer is 80–130°C.

9. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The glass transition temperature of the adhesive polymer is 85–125°C.

10. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The glass transition temperature of the adhesive polymer is 90–120°C.

11. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a4) is 0.5 to 30% by mass.

12. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a4) is 0.8 to 25% by mass.

13. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a4) is 1 to 22 by mass.

14. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a1) is 15 to 22% by mass.

15. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a1) is 20 to 22% by mass.

16. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a2) is 10 to 50% by mass.

17. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a2) is 12 to 45% by mass.

18. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a2) is 14 to 44% by mass.

19. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a3) ​​is 5 to 70% by mass.

20. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a3) ​​is 12 to 65% by mass.

21. The photosensitive resin composition according to any one of claims 1 to 5, wherein, Based on the total amount of the adhesive polymer, the content of the structural unit (a3) ​​is 15 to 64% by mass.

22. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The content of the adhesive polymer is 30 to 80 parts by mass relative to the total amount of the adhesive polymer and the photopolymerizable compound, which is 100 parts by mass.

23. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The content of the adhesive polymer is 40 to 75 parts by mass relative to the total amount of the adhesive polymer and the photopolymerizable compound, which is 100 parts by mass.

24. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The content of the adhesive polymer is 50 to 70 parts by mass relative to the total amount of the adhesive polymer and the photopolymerizable compound, which is 100 parts by mass.

25. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The content of the adhesive polymer is 50 to 60 parts by mass relative to the total amount of the adhesive polymer and the photopolymerizable compound, which is 100 parts by mass.

26. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The photopolymerization initiator contains acridine-based photopolymerization initiators.

27. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The photopolymerizable compound contains bisphenol-type di(meth)acrylate.

28. The photosensitive resin composition according to any one of claims 1 to 5, wherein, The photopolymerizable compound contains a (meth)acrylate compound having a backbone derived from dipentaerythritol or pentaerythritol.

29. A photosensitive element comprising a support and a photosensitive layer formed on the support, The photosensitive layer contains the photosensitive resin composition according to any one of claims 1 to 28.

30. A method for forming a resist pattern, comprising: The process of forming a photosensitive layer on a substrate using the photosensitive resin composition of any one of claims 1 to 28 or the photosensitive element of claim 29; The process of irradiating at least a portion of the photosensitive layer with photochemical rays to form a photocurable portion; and The process of removing at least a portion of the uncured portion of the photosensitive layer from the substrate.

31. A method for manufacturing a printed circuit board, comprising: The process of forming a conductor pattern by etching or plating a substrate with a resist pattern formed by the resist pattern forming method of claim 30.

32. The method for manufacturing a printed circuit board according to claim 31, further comprising a step of removing the resist pattern after the etching or plating process.

Images