JP7655226B2 - Photosensitive element, method for forming resist pattern, and method for manufacturing printed wiring board - Google Patents

Description

The present disclosure relates to a photosensitive element, a method for forming a resist pattern, and a method for manufacturing a printed wiring board.

In the field of printed wiring board manufacturing, photosensitive elements comprising a layer (hereinafter also referred to as "photosensitive layer") formed using a photosensitive resin composition on a support film are widely used as resist materials for etching, plating, and other processes.

Printed wiring boards are manufactured using a photosensitive element, for example, in the following manner. That is, first, the 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 to light through a mask film or the like to form a photocured portion. At this time, the support film is peeled off before or after exposure. After that, the areas of the photosensitive layer other than the photocured portion are removed with a developer to form a resist pattern. Next, the resist pattern is used as a resist to perform an etching process or a plating process to form a conductor pattern, and finally the photocured portion of the photosensitive layer (resist pattern) is peeled off (removed).

Support films used for photosensitive elements may include those with a specified haze value and those with a limited lubricant particle size (see, for example, Patent Documents 1 and 2).

JP 2001-13681 A JP 2014-74764 A

As the resolution of circuit formation has increased in recent years, the resolution required of the photosensitive elements and exposure equipment used in circuit formation has also increased, resulting in an increase in resist defects (e.g. defects such as chipped resist) caused by the lubricant or its aggregates in the support film of the photosensitive element. Furthermore, if foreign matter in the air adheres to the side of the support film on which the photosensitive layer is not formed, resist defects are likely to occur due to the foreign matter adhered to the support film when the photosensitive layer is exposed without peeling off the support film.

The present disclosure aims to provide a photosensitive element that can reduce the occurrence of resist defects, a method for forming a resist pattern using the photosensitive element, and a method for manufacturing a printed wiring board.

The photosensitive element according to the present disclosure comprises a support film and a photosensitive layer formed on a first surface of the support film, wherein the first surface of the support film has a surface resistivity of 1×10 ¹³ to 1×10 ¹⁷ Ω, and the second surface opposite the first surface has a surface resistivity of 1×10 ⁸ to 1×10 ¹² Ω.

The method for forming a resist pattern according to the present disclosure includes a lamination process in which the above-mentioned photosensitive element is laminated on a substrate in the order of a photosensitive layer and a support film; an exposure process in which a predetermined portion of the photosensitive layer is irradiated with active light through the support film to form a photocured portion; and a development process in which areas of the photosensitive layer other than the photocured portion are removed.

The method for manufacturing a printed wiring board according to the present disclosure includes a step of etching or plating a substrate having a resist pattern formed by the above-mentioned resist pattern forming method to form a conductor pattern.

The present disclosure provides a photosensitive element that can reduce the number of resist defects, a method for forming a resist pattern using the photosensitive element, and a method for manufacturing a printed wiring board.

FIG. 1 is a schematic cross-sectional view illustrating one embodiment of a photosensitive element. FIG. 2 is a schematic cross-sectional view showing one embodiment of a support film having a three-layer structure. FIG. 2 is a schematic cross-sectional view showing one embodiment of a support film having a two-layer structure.

The present disclosure will be described in detail below. In this specification, a numerical range indicated using "~" indicates a range that includes the numerical values before and after "~" as the minimum and maximum values, respectively. In a numerical range described in stages in this specification, the upper or lower limit of a numerical range of a certain stage may be replaced with the upper or lower limit of a numerical range of another stage. In a numerical range described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in an example.

In this specification, "(meth)acrylic acid" means at least one of "acrylic acid" and its corresponding "methacrylic acid", and the same applies to other similar expressions such as (meth)acrylate.

In this specification, "solids" refers to the non-volatile components excluding volatile substances such as water and solvents contained in the photosensitive resin composition, and refers to the components that remain without volatilization when the resin composition is dried, and also includes liquid, starch syrup, and wax-like components at room temperature around 25°C.

[Photosensitive element]
The photosensitive element of the present embodiment includes a support film and a photosensitive layer formed on a first surface of the support film. Fig. 1 is a schematic cross-sectional view showing one embodiment of a photosensitive element. The photosensitive element 1 according to the present embodiment includes a support film 10 and a photosensitive layer 20 as shown in Fig. 1.

(Support film)
A photosensitive layer 20 is provided on a first surface 10a of a support film 10. The support film 10 has a second surface 10b on the opposite side to the first surface 10a. The surface resistivity of the first surface 10a of the support film is greater than the surface resistivity of the second surface 10b.

From the viewpoint of reducing resist defects, the surface resistivity of the first surface is 1×10 ¹³ to 1×10 ¹⁷ Ω, and the surface resistivity of the second surface is 1×10 ⁸ to 1×10 ¹² Ω. The surface resistivity of the first surface may be 1×10 ¹⁴ to 1×10 ¹⁶ Ω. The surface resistivity of the second surface may be 1×10 ⁹ to 1×10 ¹¹ .

From the viewpoint of further reducing resist defects, the support film according to this embodiment can have a first layer containing a lubricant on the first surface side and a second layer containing an antistatic agent and a lubricant on the second surface side. The support film can have a two-layer structure having a first layer and a second layer, or a three-layer structure further having a base layer between the first layer and the second layer.

Figure 2 is a schematic cross-sectional view showing one embodiment of a three-layer support film. The support film 10 has a first layer 12, a base layer 16, and a second layer 14. The first layer 12 is located on the first surface 10a of the support film on which the photosensitive layer 20 is provided. The second layer 14 is provided on the opposite side of the base layer 16 from the first layer 12, and is located on the second surface 10b of the support film 10. The support film may be a three-layer biaxially oriented polyester film.

The first layer 12 is a layer containing a lubricant. The thickness of the first layer 12 may be 0.05 to 3.0 μm, 0.1 to 2.0 μm, or 0.2 to 1.0 μm.

The second layer 14 is a layer containing an antistatic agent and a lubricant. The thickness of the second layer 14 may be 0.05 to 3.0 μm, 0.1 to 2.0 μm, or 0.2 to 1.0 μm. The antistatic agent does not have to be uniformly dispersed in the second layer 14, and may be present on the side of the second layer 14 that is not in contact with the base layer 16 (the second surface 10b side).

The substrate layer 16 is a layer that does not contain a lubricant or an antistatic agent. The substrate layer may be composed of a polyester film containing polyester such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polyethylene-2,6-naphthalate (PEN). The thickness of the substrate layer 16 may be 5 to 40 μm, 8 to 30 μm, or 10 to 25 μm.

A three-layer support film can be produced, for example, by forming a first layer and a second layer on a base layer using known methods such as roll coating, flow coating, spray coating, curtain flow coating, dip coating, and slit die coating.

Figure 3 is a schematic cross-sectional view showing one embodiment of a support film having a two-layer structure. The support film 10 has a first layer 22 and a second layer 24. The first layer 22 is located on the first surface 10a of the support film on which the photosensitive layer 20 is provided. The second layer 24 is located on the second surface 10b. The support film may be a biaxially oriented polyester film having a two-layer structure.

The first layer 22 is a layer containing a lubricant. The thickness of the first layer 22 may be 6 to 50 μm, 8 to 40 μm, or 10 to 25 μm.

The first layer may be formed by kneading a lubricant into polyester such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polyethylene-2,6-naphthalate (PEN).

The second layer 24 is a layer containing an antistatic agent and a lubricant. The thickness of the second layer 24 may be 0.05 to 3.0 μm, 0.1 to 2.0 μm, or 0.2 to 1.0 μm. The antistatic agent does not have to be uniformly dispersed in the second layer 24, and may be present on the side of the second layer 24 that is not in contact with the first layer 22 (the second surface 10b side).

A two-layer support film can be produced, for example, by forming a first layer 22 and then forming a second layer 24 on the first layer 22 using a known method such as roll coating, flow coating, spray coating, curtain flow coating, dip coating, or slit die coating.

The average particle size of the lubricant contained in the first layer and the second layer is preferably 1 μm or less, and may be 0.1 to 1 μm, 0.1 to 0.8 μm, or 0.2 to 0.5 μm. From the viewpoint of enhancing the smoothness of the first surface 10a of the support film, it is preferable that the average particle size of the lubricant contained in the first layer is smaller than the average particle size of the lubricant contained in the second layer. The average particle size of the lubricant can be measured by observing the surface of the support film using a scanning electron microscope.

From the viewpoint of enhancing the smoothness of the first surface 10a of the support film, it is preferable that the number of lubricants contained in the first layer is smaller than the number of lubricants contained in the second layer. The number of lubricants contained in the first layer is preferably 150 or less per 15 μm×15 μm, and may be 10 to 120, or 15 to 100. The number of lubricants contained in the second layer is preferably 500 or less per 150 μm×150 μm square, and may be 200 to 480, or 300 to 460. The number of lubricants can be measured by observing the surface of the support film using a confocal laser microscope.

The lubricant is not particularly limited as long as it does not inhibit the light transmittance of the support film and is a component used in the production of polyester films, and may be an inorganic or organic lubricant. Examples of inorganic lubricants include silica, calcium carbonate, alumina, wollastonite, kaolin, zinc oxide, barium sulfate, calcium phosphate, and salts of calcium, barium, zinc, or manganese with terephthalic acid. Examples of organic lubricants include crosslinked polymers such as polystyrene and polymethyl methacrylate.

The antistatic agent can be selected within a range that does not impair the light transmittance of the support film. Examples of the antistatic agent include hydroxyl group-containing compounds such as polyoxyalkylene glycol, π-conjugated polymers such as alkoxypolythiophenes, ester products of polyhydric alcohols having three or more hydroxyl groups such as glycerin tristearate and aliphatic monocarboxylic acids having 12 or more carbon atoms, lithium metal-containing compounds such as lithium dodecylbenzenesulfonate, organic sulfonic acid metal salts such as sodium dodecylbenzenesulfonate, and lithium metal-containing compounds such as lithium trifluoromethanesulfonate.

The haze of the support film may be 0.01 to 5.0%, 0.01 to 1.5%, 0.01 to 1.0%, or 0.01 to 0.5%. Haze refers to a value measured using a commercially available haze meter (turbidity meter) in accordance with the method specified in JIS K7105. Haze can be measured, for example, using a commercially available turbidity meter such as NDH-5000 (product name, manufactured by Nippon Denshoku Industries Co., Ltd.).

The thickness of the support film may be 5 to 50 μm, 8 to 40 μm, 10 to 30 μm, or 10 to 25 μm.

(Photosensitive Layer)
The photosensitive layer 20 is a layer formed from a photosensitive resin composition. There is no particular limitation on the photosensitive resin composition used to form the photosensitive layer 20. The photosensitive resin composition may contain (A) a binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator.

The (A) binder polymer (hereinafter also referred to as "component (A)") can be produced, for example, by radical polymerization of a polymerizable monomer. Examples of the polymerizable monomer include styrene or a styrene derivative, acrylamide such as diacetone acrylamide, acrylonitrile, ethers of vinyl alcohol such as vinyl-n-butyl ether, (meth)acrylic acid alkyl esters, (meth)acrylic acid benzyl ester, (meth)acrylic acid tetrahydrofurfuryl ester, (meth)acrylic acid dimethylaminoethyl ester, (meth)acrylic acid diethylaminoethyl ester, (meth)acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, (meth)acrylic acid, α-bromoacrylic acid, α-chloroacrylic acid, β-furyl (meth)acrylic acid, β-styryl (meth)acrylic acid, 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. The polymerizable monomers may be used alone or in combination of two or more.

From the viewpoint of alkaline developability, the (A) component may have a carboxy group. The (A) component having a carboxy group can be produced, for example, by radical polymerization of a polymerizable monomer having a carboxy group and another polymerizable monomer. The polymerizable monomer having a carboxy group may be (meth)acrylic acid or methacrylic acid.

From the standpoint of achieving a well-balanced improvement in alkaline developability and alkaline resistance, the content of structural units based on polymerizable monomers having carboxy groups may be 10 to 50% by mass, 15 to 40% by mass, or 20 to 35% by mass, based on the total amount of component (A). When the carboxy group content is 10% by mass or more, alkaline developability tends to be improved, and when it is 50% by mass or less, alkaline resistance tends to be excellent.

The acid value of component (A) having a carboxy group may be 50 to 250 mg KOH/g, 50 to 200 mg KOH/g, or 100 to 200 mg KOH/g.

From the viewpoint of adhesion and peeling properties, component (A) may have a structural unit based on styrene or a styrene derivative. Styrene derivatives are polymerizable compounds in which hydrogen atoms at the α-position or aromatic ring of styrene, such as vinyltoluene and α-methylstyrene, are substituted. The content of structural units based on styrene or a styrene derivative in component (A) may be 10 to 60% by mass, 15 to 50% by mass, 35 to 50% by mass, or 40 to 50% by mass. When this content is 10% by mass or more, adhesion tends to improve, and when it is 60% by mass or less, it is possible to suppress the peeling pieces from becoming large during development, and there is a tendency to suppress the time required for peeling from increasing.

From the viewpoint of improving resolution, component (A) may have a structural unit based on benzyl (meth)acrylic acid ester. The content of structural units derived from benzyl (meth)acrylic acid ester in component (A) may be 10 to 40% by mass, 15 to 35% by mass, or 20 to 30% by mass.

From the viewpoint of improving plasticity, the (A) component may have a structural unit based on an alkyl (meth)acrylate ester. Examples of the alkyl (meth)acrylate ester include methyl (meth)acrylate ester, ethyl (meth)acrylate ester, propyl (meth)acrylate ester, butyl (meth)acrylate ester, pentyl (meth)acrylate ester, hexyl (meth)acrylate ester, heptyl (meth)acrylate ester, octyl (meth)acrylate ester, 2-ethylhexyl (meth)acrylate ester, nonyl (meth)acrylate ester, decyl (meth)acrylate ester, undecyl (meth)acrylate ester, and dodecyl (meth)acrylate ester.

The weight average molecular weight (Mw) of component (A) may be 10,000 to 300,000, 150,000 to 150,000, 200,000 to 100,000, or 25,000 to 80,000. When component (A) has an Mw of 10,000 or more, it tends to have excellent developer resistance, and when it is 300,000 or less, it tends to prevent the development time from becoming long. Component (A) may have a degree of dispersion (weight average molecular weight/number average molecular weight) of 1.0 to 3.0, or 1.0 to 2.0. When the degree of dispersion is smaller, the resolution tends to improve.

The weight average molecular weight and number average molecular weight in this specification are values measured by gel permeation chromatography (GPC) and converted using standard polystyrene as the standard sample.

The (A) component may be used alone or in combination of two or more. When two or more types of (A) components are used in combination, examples of the (A) component include two or more binder polymers made of different polymerizable monomers, two or more binder polymers having different Mw, and two or more binder polymers having different dispersities.

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

As the (B) photopolymerizable compound (hereinafter also referred to as "(B) component"), a compound having at least one ethylenically unsaturated bond in the molecule can be used. The (B) component can be used alone or in combination of two or more types.

The ethylenically unsaturated bond of component (B) is not particularly limited as long as it is photopolymerizable. Examples of ethylenically unsaturated bonds include α,β-unsaturated carbonyl groups such as (meth)acryloyl groups. Examples of photopolymerizable compounds having α,β-unsaturated carbonyl groups include α,β-unsaturated carboxylic acid esters of polyhydric alcohols, bisphenol-type (meth)acrylates, α,β-unsaturated carboxylic acid adducts of glycidyl group-containing compounds, (meth)acrylates having urethane bonds, nonylphenoxy polyethyleneoxy acrylates, (meth)acrylates having a phthalic acid skeleton, and (meth)acrylic acid alkyl esters.

Examples of α,β-unsaturated carboxylic acid esters of polyhydric alcohols include polyethylene glycol di(meth)acrylate having 2 to 14 ethylene groups, polypropylene glycol di(meth)acrylate having 2 to 14 propylene groups, polyethylene-polypropylene glycol di(meth)acrylate having 2 to 14 ethylene 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 skeleton derived from dipentaerythritol or pentaerythritol. "EO-modified" means that it has a block structure of ethylene oxide (EO) groups, and "PO-modified" means that it has a block structure of propylene oxide (PO) groups.

From the viewpoint of improving the flexibility of the resist pattern, the (B) component may contain a polyalkylene glycol di(meth)acrylate. The polyalkylene glycol di(meth)acrylate may have at least one of an EO group and a PO group, or may have both an EO group and a PO group. In a polyalkylene glycol di(meth)acrylate having both an EO group and a PO group, the EO group and the PO group may each be present in a continuous block form or may be present randomly. In addition, the PO group may be either an oxy-n-propylene group or an oxyisopropylene group. In the (poly)oxyisopropylene group, the secondary carbon of the propylene group may be bonded to an oxygen atom, and the primary carbon may be bonded to an oxygen atom.

Commercially available examples of polyalkylene glycol di(meth)acrylates include FA-023M (manufactured by Hitachi Chemical Co., Ltd.), FA-024M (manufactured by Hitachi Chemical Co., Ltd.), and NK Ester HEMA-9P (manufactured by Shin-Nakamura Chemical Co., Ltd.).

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

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, PO-modified urethane di(meth)acrylates include, for example, "UA-13" (manufactured by Shin-Nakamura Chemical Co., Ltd.).

From the viewpoint of facilitating the formation of a thick resist pattern and improving resolution and adhesion in a well-balanced manner, component (B) may contain a (meth)acrylate compound having a skeleton derived from dipentaerythritol or pentaerythritol. The (meth)acrylate compound having a skeleton derived from dipentaerythritol or pentaerythritol preferably has four or more (meth)acryloyl groups, and may be dipentaerythritol penta(meth)acrylate or dipentaerythritol hexa(meth)acrylate.

As component (B), a polyfunctional (meth)acrylate compound obtained by reacting a polyhydric alcohol with an α,β-unsaturated carboxylic acid may be contained. The polyfunctional (meth)acrylate compound may have at least one of an EO group and a PO group, or may have both an EO group and a PO group. As such a compound, dipentaerythritol (meth)acrylate having an EO group, etc., can be used. As a commercially available product of dipentaerythritol (meth)acrylate having an EO group, for example, DPEA-12 (manufactured by Nippon Kayaku Co., Ltd.) etc. can be mentioned.

From the viewpoint of improving the resolution and release properties after curing, component (B) may contain a bisphenol type (meth)acrylate, and among the bisphenol type (meth)acrylates, it may contain a bisphenol A type (meth)acrylate. Examples of bisphenol A type (meth)acrylates include 2,2-bis(4-((meth)acryloxypolyethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloxypolyethoxypolypropoxy)phenyl)propane.

Commercially available examples include 2,2-bis(4-((meth)acryloxydiethoxy)phenyl)propane (BPE-200, Shin-Nakamura Chemical Co., Ltd.), 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane (BPE-500, Shin-Nakamura Chemical Co., Ltd.), and FA-321M (Hitachi Chemical Co., Ltd.).

Examples of nonylphenoxy polyethyleneoxyacrylates include nonylphenoxytetraethyleneoxyacrylate, nonylphenoxypentaethyleneoxyacrylate, nonylphenoxyhexaethyleneoxyacrylate, nonylphenoxyheptaethyleneoxyacrylate, nonylphenoxyoctaethyleneoxyacrylate, nonylphenoxynonaethyleneoxyacrylate, nonylphenoxydecaethyleneoxyacrylate, and nonylphenoxyundecaethyleneoxyacrylate.

Examples of (meth)acrylates having a phthalic acid skeleton include γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β'-(meth)acryloyloxyethyl-o-phthalate, and β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate. γ-chloro-β-hydroxypropyl-β'-methacryloyloxyethyl-o-phthalate is commercially available as FA-MECH (Hitachi Chemical Co., Ltd.).

The (C) photopolymerization initiator (hereinafter also referred to as "component (C)") is not particularly limited as long as it can polymerize component (B), and can be appropriately selected from commonly used photopolymerization initiators. Component (C) can be used alone or in combination of two or more types.

Examples of component (C) include photopolymerization initiators such as acylphosphine oxides, oxime esters, aromatic ketones, quinones, alkylphenones, imidazoles, acridines, phenylglycine, and coumarins. Component (C) may contain an acridine-based photopolymerization initiator, a phenylglycine-based photopolymerization initiator, or an imidazole-based photopolymerization initiator in order to improve sensitivity and resolution in a well-balanced manner.

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-acridinyl)ethane, 1,4-bis(9-acridinyl)butane, 1,6-bis(9-acridinyl)hexane, and 1,8-bis(9-acridinyl)octa bis(9-acridinyl)alkanes such as 1,10-bis(9-acridinyl)decane, 1,12-bis(9-acridinyl)dodecane, 1,14-bis(9-acridinyl)tetradecane, 1,16-bis(9-acridinyl)hexadecane, 1,18-bis(9-acridinyl)octadecane, and 1,20-bis(9-acridinyl)eicosane; 1,3-bis(9-acridinyl)-2-oxapropane, 1,3-bis(9-acridinyl)-2-thiapropane, and 1,5-bis(9-acridinyl)-3-thiapentane.

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

Examples of hexaarylbiimidazole-based 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)-biimidazole, Examples include 2,2'-bis-(2-fluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3-difluoromethylphenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,4-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, and 2,2'-bis-(2,5-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole.

The content of component (C) may be 0.1 to 10 parts by mass, 1 to 5 parts by mass, or 2 to 4.5 parts by mass, relative to 100 parts by mass of the total amount of components (A) and (B). When the content of component (C) is 0.1 part by mass or more, photosensitivity, resolution, and adhesion tend to be improved, and when it is 10 parts by mass or less, resist pattern formability tends to be better.

The photosensitive resin composition according to this embodiment may further contain (D) a photosensitizer (hereinafter also referred to as "component (D)"). By containing component (D), it is possible to effectively utilize the absorption wavelength of the actinic radiation used for exposure. The component (D) may be used alone or in combination of two or more types.

Examples of the (D) component include a dialkylaminobenzophenone compound, a pyrazoline compound, an anthracene compound, a coumarin compound, a xanthone compound, a thioxanthone compound, an oxazole compound, a benzoxazole compound, a thiazole compound, a benzothiazole compound, a triazole compound, a stilbene compound, a triazine compound, a thiophene compound, a naphthalimide compound, a triarylamine compound, and an aminoacridine compound. The (D) component may contain a pyrazoline compound or an anthracene compound from the viewpoint of further improving resolution.

Examples of pyrazoline compounds include 1-(4-methoxyphenyl)-3-styryl-5-phenyl-pyrazoline, 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, 1,5-bis-(4-methoxyphenyl)-3-(4-methoxystyryl)-pyrazoline, 1-(4-isopropylphenyl)-3-styryl-5-phenyl-pyrazoline, 1-phenyl-3-(4-isopropylstyryl)-5-(4-isopropylphenyl)-pyrazoline, and 1,5-bis-(4-isopropylphenyl)-3-(4-isopropylphenyl)-pyrazoline. propylstyryl)-pyrazoline, 1-(4-methoxyphenyl)-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(4-isopropyl-styryl)-5-(4-isopropyl-phenyl) 1-(4-methoxyphenyl)-3-(4-isopropylstyryl)-5-(4-isopropylphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, 1-phenyl-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(3,4-dimethoxystyryl)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,6-dimethoxystyryl)-5-(2,6- dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,5-dimethoxystyryl)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(3,4-dimethoxystyryl)- styryl)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,6-dimethoxystyryl)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,5-dimethoxystyryl)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl )-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(3,4-dimethoxystyryl)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,6-dimethoxystyryl)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,5-dimethoxystyryl)-5-(2,5-dimethoxyphenyl) -pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(3,4-dimethoxystyryl)-5-(3,4-dimethoxyphenyl)-pyrazoline 1-(4-isopropyl-phenyl)-3-(2,6-dimethoxystyryl)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(2,5-dimethoxystyryl)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, and 1-(4-isopropyl-phenyl)-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl)-pyrazoline.

Examples of anthracene compounds include 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-dibutoxyanthracene, and 9,10-dipentoxyanthracene.

From the viewpoint of improving light sensitivity and resolution, the content of component (D) may be 0.01 to 5 parts by mass, 0.01 to 1 part by mass, or 0.01 to 0.2 parts by mass per 100 parts by mass of the total amount of components (A) and (B).

The photosensitive resin composition according to this embodiment may further contain additives such as dyes, photocoloring agents, thermal color-developing inhibitors, plasticizers, pigments, fillers, defoamers, flame retardants, adhesion-imparting agents, leveling agents, peeling promoters, antioxidants, fragrances, imaging agents, thermal crosslinking agents, and polymerization inhibitors, as necessary. These additives may be used alone or in combination of two or more.

Examples of dyes include malachite green, Victoria Pure Blue, brilliant green, and methyl violet. Examples of photochromic agents include tribromophenyl sulfone, leuco crystal violet, diphenylamine, benzylamine, triphenylamine, diethylaniline, and o-chloroaniline. Examples of plasticizers include p-toluenesulfonamide.

If necessary, the photosensitive resin composition can be dissolved in a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, propylene glycol monomethyl ether, or a mixture of these solvents, to prepare a solution with a solids content of approximately 30 to 60% by mass.

The thickness of the photosensitive layer 20 may be 1 to 200 μm, 5 to 100 μm, 10 to 50 μm, or 10 to 30 μm.

(Protective film)
The photosensitive element according to this embodiment may include a protective film (not shown) on the side of the photosensitive layer 20 opposite to the support film 10. As the protective film, it is preferable to use a film that provides a smaller adhesive strength between the photosensitive layer 20 and the protective film than the adhesive strength between the photosensitive layer 20 and the support film 10. As the protective film, a polyolefin film such as polyethylene or polypropylene can be used. The protective film may be a polyethylene film.

The thickness of the protective film may be 5 to 100 μm, 5 to 70 μm, 10 to 60 μm, 10 to 50 μm, 15 to 40 μm, or 15 to 30 μm.

(Middle class)
The photosensitive element of the present embodiment may include an intermediate layer (not shown) between the support film and the photosensitive layer. The adhesive strength between the support film and the intermediate layer may be smaller than the adhesive strength between the intermediate layer and the photosensitive layer. The intermediate layer may be water-soluble or soluble in a developer. The intermediate layer is a layer formed using a resin composition for forming an intermediate layer, which will be described later.

The resin composition for forming the intermediate layer may contain a water-soluble resin. By including a water-soluble resin, the solubility of the intermediate layer to be formed tends to be improved. In addition, the layer separation between the intermediate layer to be formed and the photosensitive layer tends to be easily maintained for a long period of time, so that the stability tends to be improved. Examples of water-soluble resins include polyvinyl alcohol and polyvinylpyrrolidone. From the viewpoint of having a low oxygen permeability coefficient and being able to further suppress the deactivation of radicals generated by the active light used for exposure, the resin composition for forming the intermediate layer may contain polyvinyl alcohol. Polyvinyl alcohol can be obtained, for example, by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate. The saponification degree of the polyvinyl alcohol used in this embodiment may be 50 mol% or more, 70 mol% or more, or 80 mol% or more. By using polyvinyl alcohol having a saponification degree of 50 mol% or more, the gas barrier property of the intermediate layer can be further improved, and the resolution of the formed resist pattern tends to be further improved. In this specification, the "saponification degree" refers to a value measured in accordance with JIS K 6726 (1994) (Testing method for polyvinyl alcohol) specified by the Japanese Industrial Standards. The upper limit of the saponification degree may be 100 mol%.

The average degree of polymerization of polyvinyl alcohol may be 300 to 3500, 300 to 2500, or 300 to 1000. The average degree of polymerization of polyvinylpyrrolidone may be 10,000 to 100,000, or 10,000 to 50,000. The polyvinyl alcohol may be used in combination with two or more types of polyvinyl alcohol having different degrees of saponification, viscosities, degrees of polymerization, modified species, etc.

The resin composition for forming the intermediate layer may contain a resin that is soluble in the developer. The resin that is soluble in the developer may contain, for example, the (A) component used in the photosensitive resin composition, or may contain the (B) component. By containing a resin that is soluble in the developer, the adhesion between the intermediate layer and the photosensitive layer to be formed tends to be improved, and also tends to make it easier to form the photosensitive layer on the intermediate layer to be formed.

The resin composition for forming the intermediate layer may contain at least one solvent as necessary to improve the handleability of the resin composition or to adjust the viscosity and storage stability. Examples of the solvent include water, organic solvents, etc. Examples of the organic solvent include methanol, acetone, toluene, or a mixed solvent thereof. Methanol may be included from the viewpoint of improving the efficiency of drying when forming the intermediate layer. In addition, when the resin composition for forming the intermediate layer contains a water-soluble resin, water, and methanol, the content of methanol may be 1 to 100 parts by mass, 10 to 80 parts by mass, or 20 to 60 parts by mass per 100 parts by mass of water from the viewpoint of solubility in the water-soluble resin. The content of the water-soluble resin may be 1 to 50 parts by mass, or 10 to 30 parts by mass per 100 parts by mass of water.

The resin composition for forming the intermediate layer may contain known additives such as surfactants, plasticizers, and leveling agents. Examples of leveling agents include silicone-based leveling agents. Examples of commercially available silicone-based leveling agents include Polyflow KL-401 (manufactured by Kyoeisha Chemical Co., Ltd.). When a leveling agent is contained, the content of the leveling agent may be 0.01 to 2.0 parts by mass or 0.05 to 1.0 parts by mass per 100 parts by mass of the resin composition for forming the intermediate layer, from the viewpoint of ease of forming the intermediate layer.

The surfactant may include a silicone-based surfactant or a fluorine-based surfactant from the viewpoint of improving the peelability from the support film. These surfactants may be used alone or in combination of two or more. When a surfactant is included, the content of the surfactant may be 0.01 to 1.0 parts by mass, 0.05 to 0.5 parts by mass, or 0.1 to 0.3 parts by mass relative to 100 parts by mass of the resin composition for forming the intermediate layer from the viewpoint of ease of forming the intermediate layer.

The plasticizer may contain, for example, a polyhydric alcohol compound in order to improve the ease of forming the intermediate layer. Examples of the plasticizer include glycerins such as glycerin, diglycerin, and triglycerin; (poly)alkylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, and polypropylene glycol; and trimethylolpropane. These plasticizers may be used alone or in combination of two or more.

The thickness of the intermediate layer is not particularly limited, but may be 12 μm or less, 10 μm or less, or 8 μm or less from the viewpoint of developability. In addition, the thickness of the intermediate layer may be 1.0 μm or more, 1.5 μm or more, or 2 μm or more from the viewpoint of ease of forming the intermediate layer and resolution.

[Method of forming a resist pattern]
The method for forming a resist pattern according to this embodiment includes a lamination process in which the photosensitive layer 20 of the photosensitive element 1 is laminated on a substrate in the order of the photosensitive layer and the support film; an exposure process in which actinic rays are irradiated through the support film 10 to a predetermined portion of the photosensitive layer 20 to form a photocured portion; and a development process in which areas of the photosensitive layer 20 other than the photocured portion are removed.

In the lamination process, for example, the photosensitive layer and the support film of the photosensitive element are laminated on the substrate in this order. In the lamination process, the photosensitive layer 20 can be laminated on the substrate by, for example, removing a protective film on the photosensitive layer 20 when the protective film is present thereon, and then heating the photosensitive layer 20 to about 70 to 130°C while pressing the layer against the substrate at a pressure of about 0.1 to 1 MPa. In the lamination process, lamination under reduced pressure is also possible. The surface of the substrate on which the photosensitive layer 20 is laminated is usually a metal surface, but is not particularly limited. In order to further improve lamination, the substrate may be preheated.

Next, in the exposure step, for example, active light rays are irradiated to a predetermined portion of the photosensitive layer 20 through the support film 10 to form a photocured portion in the photosensitive layer 20. Examples of exposure methods include a method of irradiating active light rays in an image-wise manner through a negative or positive mask pattern called artwork (mask exposure method), a method of irradiating active light rays in an image-wise manner by a projection exposure method, and a method of irradiating active light rays in an image-wise manner by a direct imaging exposure method such as an LDI (Laser Direct Imaging) exposure method or a DLP (Digital Light Processing) exposure method.

As a light source for actinic rays, any known light source can be used, for example, a carbon arc lamp, a mercury vapor arc 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, a semiconductor laser, etc., which effectively emits ultraviolet light and visible light.

From the viewpoint of improving adhesion, post-exposure bake (PEB) may be performed after exposure and before development. The temperature when performing PEB may be 50 to 100°C. As a heater, a hot plate, a box dryer, a heating roll, etc. may be used.

In the development process, at least a portion of the photosensitive layer other than the photocured portion is removed from the substrate, thereby forming a resist pattern on the substrate.

In the development process, the support film 10 is peeled off and removed from the photosensitive layer 20, and then the areas of the photosensitive layer other than the photocured portion are removed. In the development process, the unexposed areas (uncured areas) of the photosensitive layer 20 are removed and developed by, for example, wet development using a developer such as an alkaline aqueous solution, a water-based developer, or an organic solvent, or dry development, to produce a resist pattern.

Examples of the alkaline aqueous solution include a 0.1 to 5% by mass sodium carbonate solution, a 0.1 to 5% by mass potassium carbonate solution, and a 0.1 to 5% by mass sodium hydroxide solution. The pH of the alkaline aqueous solution is preferably in the range of 9 to 11. The temperature of the alkaline aqueous solution is adjusted according to the developability of the photosensitive layer 20. The alkaline aqueous solution may also contain a surfactant, an antifoaming agent, an organic solvent, etc. Examples of the development method include a dipping method, a spraying method, a brushing method, and a slapping method.

As a treatment after the development step, the resist pattern may be further hardened by heating at about 60 to 250° C. or exposing to about 0.2 to 10 J/cm ² , if necessary.

[Method of manufacturing a printed wiring board]
The method for producing a printed wiring board according to the present embodiment includes a step of forming a conductor pattern by etching or plating a substrate having a resist pattern formed by the above-described method for forming a resist pattern. Here, the etching or plating of the substrate can be performed by etching or plating the surface of the substrate by a known method using the resist pattern as a mask.

Examples of the etching solution used for etching include a cupric chloride solution, a ferric chloride solution, and an alkaline etching solution. Examples of plating include copper plating, solder plating, nickel plating, and gold plating.

After etching or plating, the resist pattern can be stripped off, for example, with an aqueous solution that is more strongly alkaline than the aqueous solution used for development. Examples of such strongly alkaline aqueous solutions include a 1-10% by weight aqueous solution of sodium hydroxide and a 1-10% by weight aqueous solution of potassium hydroxide. Stripping methods include, for example, a dipping method and a spraying method. The printed wiring board on which the resist pattern is formed may be a multilayer printed wiring board and may have small diameter through holes.

When plating is performed on a substrate that has an insulating layer and a conductor layer formed on the insulating layer, it is necessary to remove the conductor layer other than the resist pattern. Examples of this removal method include a method in which the resist pattern is peeled off and then lightly etched; a method in which the plating is followed by solder plating or the like and then the resist pattern is peeled off to mask the wiring portion with solder, and then the conductor layer is treated with an etching solution that can etch only the portion not masked by solder.

The above describes a preferred embodiment of the present invention, but the present invention is in no way limited to the above embodiment.

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

[Photosensitive resin composition]
Photosensitive resin compositions were prepared by mixing the components in the amounts (parts by mass) shown in Table 1. Details of each component shown in Table 1 are as follows.

(Binder Polymer)
A-1: Ethylene glycol monomethyl ether/toluene solution (solid content: 40% by mass) of a copolymer of methacrylic acid/methyl methacrylate/styrene/benzyl methacrylate (mass ratio: 27/5/45/23, Mw: 45,000, acid value: 107 mg KOH/g)
(Photopolymerizable Compound)
FA-321M: EO-modified bisphenol A dimethacrylate (Hitachi Chemical Co., Ltd., number of EO groups: 10 (average value))
FA-024M: Polyalkylene glycol dimethacrylate (Hitachi Chemical Co., Ltd., number of EO groups: 12 (average value), number of PO groups: 4 (average value))
BPE-200: 2,2-bis(4-(methacryloxydiethoxy)phenyl)propane (Shin-Nakamura Chemical Co., Ltd.)
(Photopolymerization initiator)
B-CIM: 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole (Hodogaya Chemical Co., Ltd.)
(Sensitizer)
EAB: 4,4'-bis(diethylamino)benzophenone (manufactured by Hodogaya Chemical Co., Ltd.)

[Support film]
As support films for photosensitive elements, support films S1 to S7 (thickness: 16 μm) having the layer structures shown in Table 2 were prepared.
S1: Three-layer biaxially oriented polyester film (Toray Industries, Inc., product name "QS64", thickness of first layer and second layer: 1 μm or less)
S2: Three-layer biaxially oriented polyester film (Toray Industries, Inc., product name "QS66", thickness of first layer and second layer: 1 μm or less)
S3: Two-layer biaxially oriented polyester film (manufactured by Mitsubishi Chemical Corporation, product name "R-705", thickness of second layer: 1 μm or less)
S4: Three-layer biaxially oriented polyester film (Toray Industries, Inc., product name "FB40", thickness of first layer and second layer: 1 μm or less)
S5: Three-layer biaxially oriented polyester film (Toray Industries, Inc., product name "QS61", thickness of first layer and second layer: 1 μm or less)
S6: Three-layer biaxially oriented polyester film (Toray Industries, Inc., product name "QS63", thickness of first layer and second layer: 1 μm or less)

(Surface resistivity of support film)
The support film cut to 10 cm x 10 cm was placed in an environment with a temperature of 23° C. and a humidity of 60±10%. An electrode was placed on the support film, and the surface resistivity was measured after leaving it for 1 minute at 100 V using a digital ultra-high resistance/microcurrent meter (ADCMT Corporation, product name "8340A").

(Average particle size of lubricant)
The surface of the support film was observed using a scanning electron microscope "SU-1500" (manufactured by Hitachi, Ltd.) and the average particle size of the lubricant was measured.

(Number of lubricants)
The surface of the support film was observed using a confocal laser microscope "OPTELICS HYBRID" (Lasertec Corporation), and the number of lubricant particles present in a 150 μm×150 μm square was counted.

[Photosensitive element]
The solution of the photosensitive resin composition was uniformly applied onto the first layer of the support film using a comma coater. The solution was then dried for 2 minutes in a hot air convection dryer at 100° C. to form a photosensitive layer having a thickness of 15 μm. A PE film (manufactured by Tamapoly Corporation, product name "NF-15A", thickness: 28 μm) was then laminated onto the photosensitive layer as a protective film to produce a photosensitive element.

(Evaluation of Resist Pattern)
The copper surface of a copper-clad laminate (manufactured by Hitachi Chemical Co., Ltd., product name "MLC-E-679"), which is a glass epoxy material with copper foil (thickness: 35 μm) laminated on both sides, was pickled, washed with water, and then dried with an air flow. The obtained copper-clad laminate was heated to 80°C, and a photosensitive element was laminated so that the photosensitive layer was in contact with the copper surface while peeling off the protective film. In this way, a laminate was obtained in which the copper-clad laminate, the photosensitive layer, and the support film were laminated in this order. The lamination was performed using a heat roll at 120°C at a pressure of 0.4 MPa and a roll speed of 1.5 m/min.

Using a phototool with a 41-step tablet, a glass chrome-type phototool with a wiring pattern of line width/space width of 2/2 to 20/20 (unit: μm) as a negative for resolution evaluation, and a projection exposure machine (UX-7 series, manufactured by Ushio Inc.) with a high-pressure mercury lamp, the photosensitive layer of the laminate was exposed with an irradiation energy amount that resulted in 9 remaining steps after development of the 41-step tablet. Next, the support film was peeled off, and development was performed by spraying a 1% by weight aqueous solution of sodium carbonate at 30°C for twice the minimum development time, removing the unexposed parts and carrying out development.

Using a scanning electron microscope "SU-1500" (manufactured by Hitachi, Ltd.), three resist patterns with a resist width of 10 μm, space width of 10 μm, and line length of 18 mm were observed, and the number of resist defects of 1 μm or more was evaluated.

1...photosensitive element, 10...support film, 10a...first side, 10b...second side, 12, 22...first layer, 14, 24...second layer, 16...base layer, 20...photosensitive layer.

Claims (8)

A photosensitive element comprising a support film and a photosensitive layer formed on a first surface of the support film,
the surface resistivity of the first surface of the support film is 1×10 ¹³ to 1×10 ¹⁷ Ω, and the surface resistivity of the second surface opposite to the first surface is 1×10 ⁸ to 1×10 ¹² Ω;
the photosensitive layer is a layer formed from a photosensitive resin composition containing (A) a binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator, the (A) binder polymer has a structural unit based on a (meth)acrylic acid benzyl ester, and a content of the structural unit derived from the (meth)acrylic acid benzyl ester is 10 to 40 mass% based on the total amount of the (A) binder polymer,
The photosensitive element , wherein the photoinitiator comprises an imidazole-based photoinitiator . The photosensitive element of claim 1, wherein the support film has a first layer containing a lubricant on the first surface side and a second layer containing an antistatic agent and a lubricant on the second surface side. The photosensitive element according to claim 2, wherein the lubricant has an average particle size of 1 μm or less. The photosensitive element according to claim 2 or 3, wherein the average particle size of the lubricant contained in the first layer is smaller than the average particle size of the lubricant contained in the second layer. The photosensitive element according to any one of claims 2 to 4, wherein the support film further has a base layer between the first layer and the second layer, and the base layer is a layer that does not contain a lubricant or an antistatic agent. The photosensitive element according to claim 5, wherein the support film is a three-layer biaxially oriented polyester film. A lamination step of laminating the photosensitive element according to any one of claims 1 to 6 on a substrate in the order of a photosensitive layer and a support film;
an exposure step of irradiating a predetermined portion of the photosensitive layer with active light through the support film to form a photocured portion;
a developing step of removing an area of the photosensitive layer other than the photocured portion;
A method for forming a resist pattern comprising the steps of: A method for manufacturing a printed wiring board, comprising a step of forming a conductor pattern by etching or plating a substrate having a resist pattern formed by the resist pattern forming method according to claim 7.

Images