JPWO2013125429A1 - Photosensitive resin composition, photosensitive element, resist pattern forming method and printed wiring board manufacturing method - Google Patents

Abstract

The present invention is a photosensitive resin composition containing a binder polymer, a photopolymerizable compound and a photopolymerization initiator, the binder polymer having a structural unit based on ethyl (meth) acrylate, and (meta ) It relates to a photosensitive resin composition in which the content of structural units based on ethyl acrylate is less than 9% by mass relative to the total amount of binder polymer and photopolymerizable compound.

Description

  The present invention relates to a photosensitive resin composition, a photosensitive element, a resist pattern forming method, and a printed wiring board manufacturing method.

  In the field of manufacturing printed wiring boards, photosensitive resin compositions are widely used as resist materials used for etching or plating. A photosensitive resin composition includes a support film and a layer (hereinafter, referred to as “photosensitive resin composition layer”) formed using the photosensitive resin composition on the support film. Often used as a laminate.

  A printed wiring board is manufactured as follows, for example. First, the photosensitive resin composition layer of the photosensitive element is laminated (laminated) on the circuit forming substrate (lamination step). Next, after peeling off and removing the support film, the exposed portion is cured by irradiating a predetermined portion of the photosensitive resin composition layer with actinic rays (exposure step). Thereafter, by removing (developing) the unexposed portion from the substrate, a resist pattern made of a cured product of the photosensitive resin composition is formed on the substrate (developing step). An etching process or a plating process is performed on the obtained resist pattern to form a circuit on the substrate (circuit forming process), and finally the resist is peeled and removed to produce a printed wiring board (peeling process).

  As an exposure method, conventionally, a method of exposing via a photomask using a mercury lamp as a light source has been used. In recent years, a direct drawing exposure method called DLP (Digital Light Processing) or LDI (Laser Direct Imaging) for directly drawing pattern digital data on a photosensitive resin composition layer has been used. This direct drawing exposure method has been introduced in order to produce a high-density package substrate because the alignment accuracy is better than the exposure method through a photomask and a high-definition pattern can be obtained.

  In the exposure process, it is necessary to shorten the exposure time in order to improve production efficiency. However, in the above-described direct drawing exposure method, in addition to using monochromatic light such as a laser as a light source and irradiating a light beam while scanning the substrate, a long exposure time is required as compared with an exposure method using a conventional photomask. Tend. Therefore, in order to shorten the exposure time and increase the production efficiency, it is necessary to improve the sensitivity of the photosensitive resin composition than before.

  In the stripping process, it is necessary to shorten the resist stripping time in order to improve production efficiency. In addition, it is necessary to reduce the size of the peeling piece in order to prevent the peeling piece of the resist from reattaching to the circuit board and to improve the production yield. Thus, the photosensitive resin composition excellent in the peeling characteristics (peeling time, peeling piece size, etc.) after hardening is requested | required.

  Furthermore, with the recent increase in the density of printed wiring boards, there is an increasing demand for a photosensitive resin composition having excellent resolution (resolution) and adhesion.

  Conventionally, various photosensitive resin compositions have been studied in response to these requirements (see, for example, Patent Documents 1 and 2).

International Publication No. 10/103918 International Publication No. 11/114593

  However, when the conventional photosensitive resin composition is used, the sensitivity, resolution, and adhesion are excellent, but when the photosensitive resin composition layer after curing is peeled, the size of the release piece increases, and the circuit May adhere to the substrate. On the other hand, if an attempt is made to improve the peeling characteristics of the cured photosensitive resin composition layer, foaming may occur in the development process, and the developer may overflow.

  Therefore, the present invention has been made in view of the above circumstances, a photosensitive resin composition that can sufficiently reduce foaming during development, and has excellent release characteristics after curing, and photosensitiveness using the same. An object is to provide an element, a method for forming a resist pattern, and a method for producing a printed wiring board.

  The present invention is a photosensitive resin composition containing a binder polymer, a photopolymerizable compound and a photopolymerization initiator, the binder polymer having a structural unit based on ethyl (meth) acrylate, and (meta ) A photosensitive resin composition is provided in which the content of structural units based on ethyl acrylate is less than 9% by mass based on the total amount of the binder polymer and the photopolymerizable compound.

  The photosensitive resin composition of the present invention has the above-described configuration, so that excellent sensitivity, resolution and adhesion can be maintained, foaming during development can be sufficiently reduced, and release characteristics after curing can be achieved. An excellent photosensitive resin composition can be formed.

  The binder polymer may further have a structural unit based on styrene or a styrene derivative. It is preferable that content of the structural unit based on styrene or a styrene derivative is 15-50 mass% with respect to the total mass of the polymerizable monomer which comprises a binder polymer.

  Furthermore, from the viewpoint of further improving sensitivity and resolution, the photopolymerization initiator can contain an acridine compound having 1 or 2 acridinyl groups.

  This invention is also a photosensitive element provided with a support film and the photosensitive resin composition layer provided on this support film, Comprising: The photosensitive resin composition layer uses the said photosensitive resin composition. A photosensitive element is provided which is a formed layer. By using such a photosensitive element, it is possible to sufficiently reduce foaming during development and to form a resist pattern having excellent release characteristics after curing.

  The present invention further includes a laminating step of laminating a photosensitive resin composition layer formed using the photosensitive resin composition on a substrate, and irradiating a predetermined portion of the photosensitive resin composition layer with actinic rays to A resist pattern made of a cured product of the photosensitive resin composition is formed on the substrate by exposing the predetermined portion to exposure and curing, and removing a portion other than the predetermined portion of the photosensitive resin composition layer from the substrate. And a developing step for forming a resist pattern. According to the above method, it is possible to efficiently and efficiently form a resist pattern having good resolution, adhesion, resist shape, and release characteristics after curing.

  Moreover, this invention provides the manufacturing method of a printed wiring board including the process of etching or plating the board | substrate with which the resist pattern was formed by the said method. According to this manufacturing method, a printed wiring board having high-density wiring such as a high-density package substrate can be efficiently manufactured with high accuracy.

  ADVANTAGE OF THE INVENTION According to this invention, the foaming at the time of image development can fully be reduced, and the photosensitive resin composition which is excellent in the peeling characteristic after hardening, the photosensitive element using this, the formation method of a resist pattern, and a printed wiring board The manufacturing method of can be provided.

It is a schematic cross section which shows suitable embodiment of the photosensitive element of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In addition, (meth) acrylic acid in this invention means acrylic acid or methacrylic acid. In addition, “EO-modified” means a compound having a (poly) oxyethylene chain, and “PO-modified” means a compound having a (poly) oxypropylene chain. “PO-modified” means a compound having both a (poly) oxyethylene chain and a (poly) oxypropylene chain.

(Photosensitive resin composition)
The photosensitive resin composition of this embodiment includes a binder polymer (hereinafter also referred to as “component (A)”), a photopolymerizable compound (hereinafter also referred to as “component (B)”), and a photopolymerization initiator (hereinafter referred to as “the component (A)”). (C) also referred to as “component”), wherein the binder polymer has a constitutional unit based on ethyl (meth) acrylate and a constitution based on ethyl (meth) acrylate Content of a unit is less than 9 mass% with respect to the total amount of (A) component and (B) component.

  Although the manifestation mechanism of the effect of the present invention by having the above configuration is not necessarily clear, the present inventors have included the content of the constituent unit of ethyl (meth) acrylate in the photosensitive resin composition within the specified value. It is presumed that the effect of the present invention was obtained by adjusting.

<(A) component: Binder polymer>
(A) A component has a structural unit based on (meth) ethyl acrylate from a viewpoint of making resolution and adhesiveness favorable. From the viewpoint of suppressing foaming during development of the photosensitive resin composition layer and improving peelability after curing, the content of the structural unit based on ethyl (meth) acrylate of the component (A) is the photosensitive resin. It is less than 9 mass% with respect to the total amount of (A) component and (B) component in a composition, It is preferable that it is 1 mass% or more and less than 9 mass%, and it is more 3-8 mass%. preferable.

  From the viewpoint of further improving the adhesion and release properties, the content of the structural unit based on the ethyl (meth) acrylate of the component (A) is based on the total mass of the polymerizable monomer constituting the component (A). 1 to 25% by mass is preferable, and 1 to 20% by mass is more preferable. When the content is 1% by mass or more, the adhesion can be further improved, and when the content is 20% by mass or less, more excellent peeling characteristics can be obtained.

  The component (A) can be obtained, for example, by radical polymerization of ethyl (meth) acrylate and another polymerizable monomer (monomer).

  Other polymerizable monomers include, for example, (meth) acrylic acid; (meth) acrylic acid alkyl esters other than ethyl (meth) acrylate, (meth) acrylic acid cycloalkyl esters, benzyl (meth) acrylate, Benzyl (meth) acrylate derivatives, furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentanyl (meth) acrylate, (meta ) Dimethylaminoethyl acrylate, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) Acrylate, α-Bromo (meth) acrylic acid, α-Chlor (meth) (Meth) acrylic esters such as acrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic acid; styrene; substituted at the α-position or aromatic ring such as vinyltoluene, α-methylstyrene Polymerizable styrene derivatives; acrylamides such as diacetone acrylamide; acrylonitrile; esters of vinyl alcohol such as vinyl-n-butyl ether; maleic acid; maleic anhydride; monomethyl maleate, monoethyl maleate, monoisopropyl maleate Maleic acid monoesters such as fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid and propiolic acid. These may be used alone or in any combination of two or more.

  From the viewpoint of improving resolution and adhesion, the component (A) can further have a structural unit based on styrene or a styrene derivative.

  When the component (A) has a structural unit based on styrene or a styrene derivative, the content thereof is based on the total mass of the polymerizable monomer constituting the component (A) in terms of excellent adhesion and peelability. Is preferably 10 to 50% by mass, more preferably 15 to 50% by mass, and still more preferably 20 to 50% by mass. In terms of excellent adhesion, the content is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more. Further, in terms of excellent peelability, the content is preferably 70% by mass or less, more preferably 60% by mass or less, and further preferably 50% by mass or less.

  The component (A) can further have a structural unit based on methyl (meth) acrylate from the viewpoint of further improving the resolution and adhesion.

  When (A) component has a structural unit based on methyl (meth) acrylate, the content is 1-50 mass% on the basis of the total mass of the polymerizable monomer which comprises (A) component. It is preferably 10 to 50% by mass, more preferably 20 to 49% by mass, and particularly preferably 30 to 48% by mass. When the content is 1% by mass or more, the adhesion can be further improved, and when the content is 50% by mass or less, more excellent peeling characteristics can be obtained.

  From the viewpoint of improving alkali developability and peeling properties, the component (A) can have a structural unit based on (meth) acrylic acid.

  The acid value of the component (A) is preferably 90 to 250 mgKOH / g, more preferably 100 to 230 mgKOH / g, still more preferably 110 to 210 mgKOH / g, and 120 to 200 mgKOH / g. It is particularly preferred. When the acid value is 90 mgKOH / g or more, the development time can be shortened, and when it is 250 mgKOH / g or less, the adhesion can be further improved. In addition, when performing solvent image development, it is preferable to prepare the polymerizable monomer (monomer) which has carboxyl groups, such as (meth) acrylic acid, in a small quantity.

  When the weight average molecular weight (Mw) of the component (A) is measured by gel permeation chromatography (GPC) (converted by a calibration curve using standard polystyrene), it is preferably 10,000 to 100,000, and 30,000 to 100,000. More preferably, it is more preferably 50,000 to 95,000. When Mw is 10,000 or more, the adhesion can be further improved, and when it is 100,000 or less, the development time can be shortened.

  Moreover, (A) component may have the characteristic group which has photosensitivity with respect to the light which has a wavelength within the range of 350-440 nm in the molecule | numerator as needed.

  As the component (A), one type of binder polymer may be used alone, or two or more types of binder polymers may be used in any combination. As a binder polymer in the case of using two or more types in combination, for example, two or more types of binder polymers comprising different copolymer components (including different monomer units as copolymer components), two or more types of different weight average molecular weights Examples of the binder polymer include two or more types of binder polymers having different degrees of dispersion. In addition, a polymer having a multimode molecular weight distribution described in JP-A No. 11-327137 can also be used.

  The content of the component (A) is preferably 30 to 70 parts by mass, more preferably 35 to 65 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). It is especially preferable to set it as -60 mass parts. If the content is 30 parts by mass or more, a film tends to be easily formed. If the content is 70 parts by mass or less, sensitivity and resolution can be further improved.

<(B) component: photopolymerizable compound>
The component (B) is not particularly limited as long as it can be photocrosslinked, but a compound having an ethylenically unsaturated bond is preferably used. As the component (B), for example, a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid; a compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid; urethane Urethane monomers such as (meth) acrylate compounds having a bond; nonylphenoxybutaethyleneoxy (meth) acrylate, nonylphenoxyoctaethyleneoxy (meth) acrylate, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxy Ethyl-o-phthalate, β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate and alkyl (meth) acrylate Light weight having one ethylenically unsaturated bond such as ester A compatible compound is mentioned. These can be used alone or in combination of two or more.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane, 2,2- Bisphenol A-based (meth) acrylate compounds such as bis (4-((meth) acryloxypolypropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane, Polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate (repeat of oxyethylene group) The total number is 1-5), P O-modified trimethylolpropane tri (meth) acrylate, EO, PO-modified trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate And dipentaerythritol hexa (meth) acrylate. These can be used alone or in combination of two or more. Among these, 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane is FA-321M (manufactured by Hitachi Chemical Co., Ltd., product name), and tetramethylolmethane triacrylate is As A-TMM-3 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name), EO-modified trimethylolpropane trimethacrylate is TMPT-21E and TMPT-30E (manufactured by Hitachi Chemical Co., Ltd., sample name). As commercially available.

  Moreover, it is preferable that (B) component contains the photopolymerizable compound which has one ethylenically unsaturated bond from a viewpoint which improves resolution, adhesiveness, a resist shape, and the peeling characteristic after hardening with sufficient balance. In this case, the content is preferably 1 to 30% by mass and more preferably 3 to 25% by mass with respect to the total amount of the component (B).

  Examples of the photopolymerizable compound having one ethylenically unsaturated bond in the molecule include nonylphenoxypolyethyleneoxyacrylate, phthalic acid compounds, and (meth) acrylic acid alkyl esters. Among these, nonylphenoxypolyethyleneoxyacrylate or phthalic acid-based compounds are preferable from the viewpoint of improving the resolution, adhesion, resist shape, and release properties after curing in a well-balanced manner, and nonylphenoxypolyethyleneoxyacrylate and phthalic acid-based compounds are used in combination. It is more preferable.

  Nonylphenoxypolyethyleneoxyacrylate includes, for example, nonylphenoxytriethyleneoxyacrylate, nonylphenoxytetraethyleneoxyacrylate, nonylphenoxypentaethyleneoxyacrylate, nonylphenoxyhexaethyleneoxyacrylate, nonylphenoxyheptaethyleneoxyacrylate, nonylphenoxyoctaethyleneoxy Examples thereof include acrylate, nonylphenoxynonaethyleneoxyacrylate, nonylphenoxydecaethyleneoxyacrylate, and nonylphenoxyundecaethyleneoxyacrylate. These may be used alone or in any combination of two or more. “Nonylphenoxypolyethyleneoxyacrylate” is also referred to as “nonylphenoxypolyethyleneglycol acrylate”.

  Examples of the phthalic acid compound 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, among which γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate is preferable. . γ-Chloro-β-hydroxypropyl-β′-methacryloyloxyethyl-o-phthalate is commercially available as FA-MECH (manufactured by Hitachi Chemical Co., Ltd., product name). These can be used alone or in combination of two or more.

<(C) component: photopolymerization initiator>
(C) Although it can use without a restriction | limiting especially as a component, The acridine compound which has an acridinyl group 1 or 2 can be included. That is, the component (C) is composed of an acridine compound having two acridinyl groups (hereinafter also referred to as “(C1) component”) and an acridine compound having one acridinyl group (hereinafter also referred to as “(C2) component”). It is preferable that at least one compound selected from the group consisting of:

  Examples of the component (C1) include acridine compounds represented by the following general formula (1).

In the formula (1), R ¹ represents an alkylene group having 2 to 20 carbon atoms, an oxadialkylene group having 2 to 20 carbon atoms, or a thiodialkylene group having 2 to 20 carbon atoms. From the viewpoint of more reliably obtaining the effect exhibited by the photosensitive resin composition of the present embodiment, R ¹ is preferably an alkylene group having 2 to 20 carbon atoms, and more preferably an alkylene group having 4 to 14 carbon atoms. preferable.

  Examples of the compound represented by the general formula (1) include 1,2-bis (9-acridinyl) ethane, 1,3-bis (9-acridinyl) propane, and 1,4-bis (9-acridinyl). Butane, 1,5-bis (9-acridinyl) pentane, 1,6-bis (9-acridinyl) hexane, 1,7-bis (9-acridinyl) heptane, 1,8-bis (9-acridinyl) octane, 1,9-bis (9-acridinyl) nonane, 1,10-bis (9-acridinyl) decane, 1,11-bis (9-acridinyl) undecane, 1,12-bis (9-acridinyl) dodecane, 14-bis (9-acridinyl) tetradecane, 1,16-bis (9-acridinyl) hexadecane, 1,18-bis (9-acridinyl) octadecane, 1,20- Bis (9-acridinyl) alkanes such as su (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 is mentioned. These can be used alone or in combination of two or more.

From the viewpoint of improving sensitivity and resolution, an acridine compound in which R ¹ in formula (1) is a heptylene group (for example, product name “N-1717” manufactured by ADEKA Corporation) is used as the component (C1). It is preferable to include.

  The content of the component (C1) is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B) from the viewpoint of sensitivity, resolution, and adhesion. More preferably, it is 5-5 mass parts, More preferably, it is 1-5 mass parts, It is especially preferable that it is 1-3 mass parts. When the blending amount is 0.1 parts by mass or more, better sensitivity, resolution, or adhesion is easily obtained, and when it is 10 parts by mass or less, a more excellent resist shape can be obtained.

  Examples of the component (C2) include acridine compounds represented by the following general formula (2).

In Formula (2), R ² represents a halogen atom, an amino group, a carboxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alkylamino group having 1 to 6 carbon atoms, and a is An integer of 0 to 5 is shown.

  Examples of the acridine compound represented by the general formula (2) include 9-phenylacridine, 9- (p-methylphenyl) acridine, 9- (m-methylphenyl) acridine, and 9- (p-chlorophenyl) acridine. , 9- (m-chlorophenyl) acridine, 9-aminoacridine, 9-dimethylaminoacridine, 9-diethylaminoacridine and 9-pentylaminoacridine. These can be used alone or in combination of two or more.

  The component (C) may contain a photopolymerization initiator other than the components (C1) and (C2).

  Examples of the photopolymerization initiator other than the components (C1) and (C2) include benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4. '-Diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and 2-methyl-1- [4- (methylthio) Aromatic ketones such as phenyl] -2-morpholino-propanone-1; 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2 -Phenylanthraquinone, 2,3-diphenylanthra Quinones such as non, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone and 2,3-dimethylanthraquinone; 2- ( o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5- 2,4,5 such as diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer and 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer -Triarylimidazole dimer; benzyl derivatives such as benzyldimethyl ketal; 9,10-dimethoxyanthracene, 9 Substituted anthracene compounds such as 10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-dibutoxyanthracene and 9,10-dipentoxyanthracene; coumarin compounds, oxazole compounds, pyrazoline compounds and triarylamine compounds Can be mentioned. These can be used alone or in combination of two or more. A combination of a thioxanthone compound and a tertiary amine compound can also be used, such as a combination of diethylthioxanthone and dimethylaminobenzoic acid.

  In the case where the photosensitive resin composition contains a photopolymerization initiator other than the components (C1) and (C2), the content thereof is the components (A) and (B) from the viewpoints of sensitivity and internal photocurability. It is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 7 parts by mass, and particularly preferably 0.2 to 5 parts by mass with respect to 100 parts by mass of the total solid content. preferable.

  (C) Component content is 0.01-20 mass parts with respect to 100 mass parts of solid content of (A) component and (B) component from a sensitivity, adhesiveness, and a viewpoint of internal photocurability. It is preferable that it is 0.05-10 mass parts, and it is especially preferable that it is 0.1-5 mass parts.

<Amine compound>
The photosensitive resin composition of the present embodiment can further contain (D) an amine compound (hereinafter also referred to as “component (D)”).

  Examples of the component (D) include bis [4- (dimethylamino) phenyl] methane, bis [4- (diethylamino) phenyl] methane, and leucocrystal violet. These can be used alone or in combination of two or more.

  When the photosensitive resin composition contains the component (D), the content is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B). It is more preferably 0.1 to 5 parts by mass, still more preferably 0.6 to 2 parts by mass, and particularly preferably 1 to 2 parts by mass. When the content is 0.01 parts by mass or more, more excellent sensitivity is easily obtained, and when the content is 10 parts by mass or less, an excessive component (D) tends to hardly precipitate as foreign matter after film formation.

<Other ingredients>
If necessary, the photosensitive resin composition of the present embodiment includes a photopolymerizable compound (such as an oxetane compound) having at least one cationically polymerizable cyclic ether group in the molecule, a cationic polymerization initiator, malachite green, and the like. Dyes, photochromic agents such as tribromomethylphenylsulfone, leucocrystal violet, thermochromic inhibitors, plasticizers such as p-toluenesulfonamide, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion imparting An agent, a leveling agent, a peeling accelerator, an antioxidant, a fragrance, an imaging agent, a thermal crosslinking agent and the like may be contained. These are used alone or in combination of two or more. These contents are preferably about 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of component (A) (binder polymer) and component (B) (photopolymerizable compound).

(Photosensitive resin composition solution)
The photosensitive resin composition of this embodiment can be dissolved in an organic solvent and used as a solution (coating solution) having a solid content of about 30 to 60% by mass. Examples of the organic solvent include methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether, and a mixed solvent thereof.

  The said coating liquid is apply | coated on surfaces, such as a metal plate, and the photosensitive resin composition layer which consists of the photosensitive resin composition of this embodiment can be formed by making it dry. Examples of the metal plate include iron alloys such as copper, copper alloys, nickel, chromium, iron, and stainless steel, preferably copper, copper alloys, and iron alloys.

  The thickness of the photosensitive resin composition layer varies depending on its use, but is preferably about 1 to 100 μm after drying. You may coat | cover the surface on the opposite side to the metal plate of the photosensitive resin composition layer with a protective film. Examples of the protective film include polymer films such as polyethylene and polypropylene.

(Photosensitive element)
FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the photosensitive element 1 of the present invention.

  The photosensitive resin composition layer 3 made of the photosensitive resin composition can be formed on the support film by applying the solution of the photosensitive resin composition onto the support film 2 and drying the solution. That is, the photosensitive resin composition layer 3 is a layer formed using the photosensitive resin composition. Thus, the photosensitive element 1 of this embodiment provided with the support film 2 and the said photosensitive resin composition layer 3 provided on this support film is obtained.

  As the support film, a polymer film formed from a polymer having heat resistance and solvent resistance such as polyester such as polyethylene terephthalate, polyolefin such as polypropylene and polyethylene, and the like can be used.

  The thickness of the support film (polymer film) is preferably 1 to 100 μm, more preferably 5 to 50 μm, and still more preferably 5 to 30 μm. When the thickness is 1 μm or more, the support film is hardly broken when the support film is peeled off, and when it is 100 μm or less, the resolution can be improved.

  The photosensitive element 1 may be provided with the protective film 4 which coat | covers the surface on the opposite side to the support film 2 of the photosensitive resin composition layer 3 as needed. As the protective film, a polymer film formed from a polyester such as polyethylene terephthalate or a polyolefin such as polypropylene or polyethylene can be used.

  The thickness of the protective film is preferably 1 to 100 μm, more preferably 5 to 50 μm, still more preferably 5 to 30 μm, and particularly preferably 15 to 30 μm. When the thickness is 1 μm or more, when the photosensitive resin composition layer and the protective film are laminated (laminated) on the substrate, the protective film is hardly broken, and when it is 100 μm or less, the cost is excellent.

  Application of the photosensitive resin composition solution onto the support film can be performed by a known method such as roll coating, comma coating, gravure coating, air knife coating, die coating, or bar coating.

  The solution is preferably dried at 70 to 150 ° C. for about 5 to 30 minutes. After drying, the amount of the remaining organic solvent in the photosensitive resin composition layer is preferably 2% by mass or less from the viewpoint of preventing diffusion of the organic solvent in the subsequent step.

  Although the thickness of the photosensitive resin composition layer in a photosensitive element changes with uses, it is preferable that it is 1-100 micrometers by the thickness after drying, it is more preferable that it is 1-50 micrometers, and it is 5-40 micrometers. Further preferred. When this thickness is 1 μm or more, it becomes easy to apply industrially, and when it is 100 μm or less, more excellent adhesion and resolution can be obtained.

  The photosensitive element may further include an intermediate layer such as a cushion layer, an adhesive layer, a light absorption layer, and a gas barrier layer.

  The obtained photosensitive element can be stored in the form of a sheet or a roll wound around a core. When it winds up in roll shape, it is preferable to wind up so that a support film may become an outer side. Examples of the core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer). From the viewpoint of end face protection, it is preferable to install an end face separator on the end face of the roll-shaped photosensitive element roll thus obtained, and it is preferable to install a moisture-proof end face separator from the standpoint of edge fusion resistance. As a packaging method, it is preferable to wrap and package in a black sheet with low moisture permeability.

(Method for forming resist pattern)
A resist pattern can be formed using the photosensitive resin composition. The resist pattern forming method according to the present embodiment includes (i) a lamination step of laminating a photosensitive resin composition layer formed using the photosensitive resin composition on a substrate, and (ii) a photosensitive resin composition. An exposure step of irradiating a predetermined portion of the physical layer with actinic rays to expose and cure the predetermined portion; and (iii) removing a portion other than the predetermined portion of the photosensitive resin composition layer from the substrate, And a development step of forming a resist pattern made of a cured product of the photosensitive resin composition on the substrate.

(I) Lamination process First, the photosensitive resin composition layer formed using the photosensitive resin composition is laminated | stacked on a board | substrate. As the substrate, a substrate (circuit forming substrate) including an insulating layer and a conductor layer formed on the insulating layer can be used.

  Lamination of the photosensitive resin composition layer on the substrate is performed, for example, by removing the protective film of the photosensitive element and then pressing the photosensitive resin composition layer of the photosensitive element on the substrate while heating. Is called. Thereby, the laminated body which consists of a board | substrate, the photosensitive resin composition layer, and the support film, and these were laminated | stacked in order is obtained.

This lamination operation is preferably performed under reduced pressure from the viewpoint of adhesion and followability. The photosensitive resin composition layer and / or the substrate is preferably heated at a temperature of 70 to 130 ° C. at a pressure of about 0.1 to 1.0 MPa (about 1 to 10 kgf / cm ² ). Although pressure bonding is preferable, these conditions are not particularly limited. In addition, if the photosensitive resin composition layer is heated to 70 to 130 ° C., it is not necessary to pre-heat the substrate in advance, but the substrate may be pre-heated in order to further improve the lamination property.

(Ii) Exposure Step Next, the predetermined portion of the photosensitive resin composition layer on the substrate is irradiated with actinic rays to expose and cure the predetermined portion. In this case, when the support film present on the photosensitive resin composition layer is transmissive to actinic rays, it can be irradiated with actinic rays through the support film, but the support film is light-shielding. In this case, after removing the support film, the photosensitive resin composition layer is irradiated with actinic rays.

  Examples of the exposure method include a method (mask exposure method) of irradiating an image with active light through a negative or positive mask pattern called an artwork. Alternatively, a method of irradiating actinic rays in an image form by a direct drawing exposure method such as an LDI (Laser Direct Imaging) exposure method or a DLP (Digital Light Processing) exposure method may be employed.

  The photosensitive resin composition of this embodiment can be used suitably for a direct drawing exposure method. That is, one of the preferred embodiments of the present invention contains a binder polymer, a photopolymerizable compound and a photopolymerization initiator, the binder polymer has a structural unit based on ethyl (meth) acrylate, and It is application to the direct drawing exposure method of the photosensitive resin composition whose content of the structural unit based on (meth) ethyl acrylate is less than 9 mass% with respect to the total amount of a binder polymer and a photopolymerizable compound.

  As the actinic ray light source, a 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 laser such as a YAG laser, a semiconductor laser, etc. Those that effectively emit ultraviolet rays, visible light, and the like are used.

  The wavelength of the actinic ray (exposure wavelength) is preferably in the range of 340 to 430 nm, more preferably in the range of 350 to 420 nm, from the viewpoint of obtaining the effect of the present invention more reliably. More preferably, it is within the range of 420 nm.

(Iii) Development Step Furthermore, a resist pattern made of a cured product of the photosensitive resin composition is formed on the substrate by removing portions other than the predetermined portion of the photosensitive resin composition layer from the substrate. When the support film is present on the photosensitive resin composition layer, the support film is removed, and then the portion (unexposed portion) other than the predetermined portion (exposed portion) is removed (developed). Development methods include wet development and dry development, but wet development is widely used.

  In the case of wet development, development is performed by a known development method using a developer corresponding to the photosensitive resin composition. Examples of the developing method include a method using a dip method, a battle method, a spray method, brushing, slapping, scraping, rocking immersion, and the like. From the viewpoint of improving the resolution, the high pressure spray method is most suitable. You may develop by combining these 2 or more types of methods.

  Examples of the developer include an alkaline aqueous solution, an aqueous developer, an organic solvent developer, and the like.

  The alkaline aqueous solution is safe and stable when used as a developer, and has good operability. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium, or potassium hydroxide; alkali carbonates such as lithium, sodium, potassium, or ammonium carbonate or bicarbonate; potassium phosphate, sodium phosphate Alkali metal phosphates such as sodium pyrophosphate and potassium pyrophosphate are used.

  As alkaline aqueous solution, 0.1-5 mass% dilute solution of sodium carbonate, 0.1-5 mass% dilute solution of potassium carbonate, 0.1-5 mass% dilute solution of sodium hydroxide, 0.1-5 A dilute solution of mass% sodium tetraborate is preferred. The pH of the alkaline aqueous solution is preferably in the range of 9 to 11, and the temperature is adjusted according to the alkali developability of the photosensitive resin composition layer. In the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for promoting development, and the like may be mixed.

(Printed wiring board manufacturing method)
A printed wiring board can be manufactured by etching or plating a substrate on which a resist pattern is formed by the above method. Etching or plating of the substrate is performed on the conductor layer of the substrate using the formed resist pattern as a mask.

  Examples of the etchant used for etching include a cupric chloride solution, a ferric chloride solution, an alkaline etchant, and a hydrogen peroxide etchant. It is preferable to use a ferric solution.

  Examples of plating methods used when plating include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-throw solder plating, watt bath (nickel sulfate-nickel chloride) plating, nickel such as nickel sulfamate Examples thereof include gold plating such as plating, hard gold plating, and soft gold plating.

  After the etching or plating is completed, the resist pattern can be peeled off with a stronger alkaline aqueous solution than the alkaline aqueous solution used for development, for example. As this strongly alkaline aqueous solution, for example, a 1 to 10% by mass sodium hydroxide aqueous solution, a 1 to 10% by mass potassium hydroxide aqueous solution and the like are used. Especially, it is preferable to use 1-10 mass% sodium hydroxide aqueous solution or potassium hydroxide aqueous solution, and it is more preferable to use 1-5 mass% sodium hydroxide aqueous solution or potassium hydroxide aqueous solution.

  Examples of the resist pattern peeling method include an immersion method and a spray method, which may be used alone or in combination. The printed wiring board on which the resist pattern is formed may be a multilayer printed wiring board or may have a small diameter through hole.

  The photosensitive resin composition of this embodiment can be used suitably for manufacture of a printed wiring board. That is, one preferred embodiment of the present invention contains a binder polymer, a photopolymerizable compound and a photopolymerization initiator, the binder polymer contains a structural unit based on ethyl (meth) acrylate, and In application to production of a printed wiring board of a photosensitive resin composition, the content of the structural unit based on the ethyl (meth) acrylate is less than 9% by mass with respect to the total amount of the binder polymer and the photopolymerizable compound. is there.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

(Preparation of solution of photosensitive resin composition)
By mixing the components (A) to (D) shown in Table 1 below in the blending amounts (g) shown in the same table, solutions of the photosensitive resin compositions of Examples 1 to 4 and Comparative Examples 1 to 5 were used. Was prepared. In addition, the compounding quantity of (A) component shown in Table 1 is the mass (solid content) of a non-volatile part, and the compounding quantity of (B) component is a solid content. Details of each component shown in Table 1 are as follows.

<(A) Binder polymer>
[Synthesis of Binder Polymer (A-1)]
A polymerizable monomer (monomer) of 130 g of methacrylic acid, 205 g of methyl methacrylate, 50 g of ethyl acrylate and 115 g of styrene (mass ratio 26/41/10/23), and 5.5 g of azobisisobutyronitrile. The solution obtained by mixing was designated as “Solution a”.

  A solution obtained by dissolving 1.2 g of azobisisobutyronitrile in 100 g of a mixed solution (mass ratio 3: 2) of 60 g of methyl cellosolve and 40 g of toluene was designated as “Solution b”.

  Into a flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas introduction tube, 450 g of a mixed solution of 270 g of methyl cellosolve and 180 g of toluene (mass ratio 3: 2) was charged, and nitrogen gas was introduced into the flask. The mixture was heated while stirring and the temperature of the mixture was raised to 80 ° C.

  The solution a was added dropwise to the mixed solution in the flask over 4 hours, and then kept at 80 ° C. for 2 hours with stirring. Next, the solution b was added dropwise to the solution in the flask over 10 minutes, and then the solution in the flask was kept at 80 ° C. for 3 hours while stirring. Further, the temperature of the solution in the flask was raised to 90 ° C. over 30 minutes, kept at 90 ° C. for 2 hours, and then cooled to obtain a solution of the binder polymer (A-1).

  The binder polymer (A-1) had a non-volatile content (solid content) of 45.0% by mass, a weight average molecular weight of 75,000, and an acid value of 170 mgKOH / g.

The weight average molecular weight was measured by gel permeation chromatography (GPC) and derived by conversion using a standard polystyrene calibration curve. The GPC conditions are shown below.
GPC conditions Pump: Hitachi L-6000 type (manufactured by Hitachi, Ltd., product name)
Column: Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (above, manufactured by Hitachi Chemical Co., Ltd., product name)
Eluent: Tetrahydrofuran Measurement temperature: 40 ° C
Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI (manufactured by Hitachi, Ltd., product name)

[Synthesis of Binder Polymer (A-2)]
A polymerizable monomer (monomer) of 130 g of methacrylic acid, 230 g of methyl methacrylate, 25 g of ethyl acrylate and 115 g of styrene (mass ratio 26/46/5/23), 5.5 g of azobisisobutyronitrile. A solution of the binder polymer (A-2) was obtained in the same manner as in the case of obtaining the solution of the binder polymer (A-1) except that the solution obtained by mixing was designated as “solution a”. The binder polymer (A-2) had a non-volatile content (solid content) of 45.0% by mass, a weight average molecular weight of 75,000, and an acid value of 170 mgKOH / g.

[Synthesis of Binder Polymer (A-3)]
A polymerizable monomer (monomer) of 130 g of methacrylic acid, 195 g of methyl methacrylate, 75 g of ethyl acrylate and 100 g of styrene (mass ratio 26/39/15/20), and 4.0 g of azobisisobutyronitrile. A solution of the binder polymer (A-3) was obtained in the same manner as that for obtaining the solution of the binder polymer (A-1) except that the solution obtained by mixing was designated as “solution a”. The binder polymer (A-3) had a nonvolatile content (solid content) of 45.0 mass%, a weight average molecular weight of 75,000, and an acid value of 170 mgKOH / g.

[Synthesis of Binder Polymer (A-4)]
A polymerizable monomer (monomer) of 130 g of methacrylic acid, 170 g of methyl methacrylate, 100 g of ethyl acrylate and 100 g of styrene (mass ratio 26/34/20/20), and 4.0 g of azobisisobutyronitrile. A solution of the binder polymer (A-4) was obtained in the same manner as that for obtaining the solution of the binder polymer (A-1) except that the solution obtained by mixing was designated as “solution a”. The binder polymer (A-4) had a nonvolatile content (solid content) of 45.0% by mass, a weight average molecular weight of 75,000, and an acid value of 170 mgKOH / g.

[Synthesis of Binder Polymer (A-5)]
A polymerizable monomer (monomer) of 130 g of methacrylic acid, 145 g of methyl methacrylate, 125 g of ethyl acrylate and 100 g of styrene (mass ratio 26/29/25/20), and 4.0 g of azobisisobutyronitrile. A solution of the binder polymer (A-5) was obtained in the same manner as that for obtaining the solution of the binder polymer (A-1) except that the solution obtained by mixing was designated as “solution a”. The binder polymer (A-5) had a non-volatile content (solid content) of 45.0% by mass, a weight average molecular weight of 75,000, and an acid value of 170 mgKOH / g.

[Synthesis of Binder Polymer (A-6)]
A solution obtained by mixing 125 g of methacrylic acid as a polymerizable monomer (monomer), 250 g of methyl methacrylate and 125 g of styrene (mass ratio 25/50/25) and 6.5 g of azobisisobutyronitrile. A solution of the binder polymer (A-6) was obtained in the same manner as that for obtaining the solution of the binder polymer (A-1) except that the “solution a” was used. The binder polymer (A-6) had a nonvolatile content (solid content) of 45.0% by mass, a weight average molecular weight of 55000, and an acid value of 163 mgKOH / g.

[Synthesis of Binder Polymer (A-7)]
A polymerizable monomer (monomer) 100 g of methacrylic acid, 250 g of methyl methacrylate, 100 g of ethyl acrylate and 50 g of styrene (mass ratio 20/50/20/10), and 4.0 g of azobisisobutyronitrile. A solution of the binder polymer (A-7) was obtained in the same manner as that for obtaining the solution of the binder polymer (A-1) except that the solution obtained by mixing was designated as “solution a”. The binder polymer (A-7) had a non-volatile content (solid content) of 45.0 mass%, a weight average molecular weight of 80000, and an acid value of 163 mgKOH / g.

[Synthesis of Binder Polymer (A-8)]
A polymerizable monomer (monomer) of 125 g of methacrylic acid, 200 g of methyl methacrylate, 75 g of ethyl acrylate and 100 g of styrene (mass ratio 25/40/15/20) and 4.0 g of azobisisobutyronitrile. A solution of the binder polymer (A-8) was obtained in the same manner as that for obtaining the solution of the binder polymer (A-1) except that the solution obtained by mixing was designated as “solution a”. The binder polymer (A-8) had a nonvolatile content (solid content) of 45.0% by mass, a weight average molecular weight of 80000, and an acid value of 163 mgKOH / g.

  Next, the materials shown in Table 1 were blended to obtain a photosensitive resin composition solution.

<(B) Photopolymerizable compound>
FA-321M (manufactured by Hitachi Chemical Co., Ltd., product name): 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane FA-MECH (manufactured by Hitachi Chemical Co., Ltd., product name) ): Γ-chloro-β-hydroxypropyl-β′-methacryloyloxyethyl-o-phthalate FA-314A (manufactured by Hitachi Chemical Co., Ltd., product name): nonylphenoxy polyethylene glycol acrylate PDE-400 (NOF Corporation) Product name): Polypropylene glycol dimethacrylate TMPT-21E (manufactured by Hitachi Chemical Co., Ltd., product name): EO-modified trimethylolpropane trimethacrylate (ethylene oxide average 21 mol adduct)

<(C) Photopolymerization initiator>
N-1717 (manufactured by ADEKA, product name): 1,7-bis (9,9-acridinyl) heptane

<(D) Amine compound>
LCV (manufactured by Yamada Chemical Co., Ltd., product name): leuco crystal violet

<Others>
MKG (manufactured by Osaka Organic Chemical Industry Co., Ltd., product name): Malachite Green BMPS (manufactured by Sumitomo Seika Co., Ltd., product name): tribromomethylphenylsulfone

<Photosensitive element>
The above photosensitive resin composition solution was uniformly applied onto a 16 μm thick polyethylene terephthalate film (product name “G2” manufactured by Teijin Limited), and dried for 10 minutes in a hot air convection dryer at 100 ° C. And the photosensitive resin composition layer whose film thickness after drying is 35 micrometers was formed. A polyethylene protective film (manufactured by Tamapoly Co., Ltd., product name “NF-13”) is laminated on the photosensitive resin composition layer, and a polyethylene terephthalate film (support film), the photosensitive resin composition layer, and a protective film are protected. A photosensitive element in which films were laminated in order was obtained.

<Laminated substrate>
The copper surface of a copper-clad laminate (made by Hitachi Chemical Co., Ltd., product name “MCL-E-679F”) composed of a glass epoxy material and copper foil (thickness 12 μm) formed on both sides thereof is # Polishing was performed using a polishing machine having a brush equivalent to 600 (manufactured by Sankei Co., Ltd., product name), washed with water, and then dried with an air stream. After heating the obtained copper clad laminated board and heating up at 80 degreeC, the photosensitive element which concerns on Examples 1-4 and Comparative Examples 1-5 was laminated | stacked (laminated | stacked) on the copper surface of a board | substrate. Laminating is performed at a temperature of 110 ° C., a laminating pressure of 4 kgf / cm ² , a laminating speed of 1.5 m / cm so that the photosensitive resin composition layer of each photosensitive element is in close contact with the copper surface of the substrate while removing the protective film. Performed under the condition of minutes. Thus, the laminated substrate by which the photosensitive resin composition layer and the polyethylene terephthalate film were laminated | stacked on the copper surface of the board | substrate was obtained.

<Evaluation of sensitivity>
A Hitachi 41-step tablet is placed on the polyethylene terephthalate film of the laminated substrate, and a direct drawing exposure apparatus (product name “DE-1UH” manufactured by Hitachi Via Mechanics Co., Ltd.) using a semiconductor laser with a wavelength of 405 nm as a light source is used. Then, exposure was performed with a predetermined energy amount. Thereafter, the polyethylene terephthalate film was peeled off, and sprayed with a 1.0% by mass aqueous sodium carbonate solution at 30 ° C. for 24 seconds to remove the unexposed portion, and then the photocured film step tablet formed on the copper clad laminate was removed. The number of steps was measured, the amount of energy (mJ / cm ² ) at which the number of remaining steps after development was 17.0 was determined, and the sensitivity of the photosensitive resin composition was evaluated. The evaluation of sensitivity indicates that the smaller this value, the higher the sensitivity.

<Evaluation of resolution>
Using drawing data having a wiring pattern with a line width / space width of 3/3 to 100/100 (unit: μm), the amount of energy at which the number of remaining step stages after development of Hitachi 41-stage step tablet is 17.0 Then, the photosensitive resin composition layer of the laminated substrate was exposed. After performing development under the same conditions as the sensitivity evaluation above, the resist pattern is observed using an optical microscope, the unexposed areas can be completely removed, and the lines are formed without meandering or chipping. The resolution was evaluated by the minimum value between the line widths in the resist pattern. The smaller this value, the better the resolution.

<Evaluation of adhesion>
Using the drawing data having a wiring pattern with a line width / space width of n / 400 (unit: μm), and the amount of energy at which the number of remaining step steps after development of the Hitachi 41-step tablet is 17.0, the laminated substrate The photosensitive resin composition layer was exposed. After developing under the same conditions as the sensitivity evaluation above, the resist pattern is observed using an optical microscope, the unexposed areas can be completely removed, and the lines remain without meandering or chipping. The adhesion was evaluated by the minimum value of the line width n. It shows that adhesiveness is so favorable that this figure is small.

<Evaluation of foamability>
A photosensitive resin composition layer of 0.6 m ² / L in which the amount of dissolution of the photosensitive resin composition layer in the developer corresponds to 1.5 times the recommended condition (0.4 m ² / L) is used as a developer ( 1 mass% Na ₂ CO ₃ aqueous solution), this solution was circulated and stirred for 90 minutes with a small developing machine, and the foaming was visually observed to measure the foaming height. The lower the foam height, the lower the foamability.

<Evaluation of peeling properties>
Using the drawing data having a pattern of 60 mm × 40 mm as the peelability evaluation pattern, the photosensitive resin composition of the above laminated substrate with an energy amount that the number of remaining step steps after development of the Hitachi 41 step tablet is 17.0. The layer was exposed. Next, after performing development processing under the same conditions as in the evaluation of sensitivity and resolution, the substrate having the formed cured film was immersed in a 3.0 mass% sodium hydroxide aqueous solution at 50 ° C., and the cured film was removed from the substrate. The time until complete removal was defined as the separation time (unit: seconds). Moreover, the size of the peeling piece after peeling was observed visually, and the following references | standards evaluated. The shorter the peeling time and the smaller the peeling piece size, the better the peeling characteristics. The results are shown in Table 2.
Peeling piece size L: Sheet shape.
M: 30-40 mm square.
S: smaller than 30 mm square.

  As shown in Table 2, the photosensitive resin compositions of Examples 1 to 4 have good adhesion and resolution, can reduce foaming during development, and have excellent release characteristics after curing. Can be confirmed.

  DESCRIPTION OF SYMBOLS 1 ... Photosensitive element, 2 ... Support film, 3 ... Photosensitive resin composition layer, 4 ... Protective film.

Claims (7)

A photosensitive resin composition containing a binder polymer, a photopolymerizable compound and a photopolymerization initiator,
The binder polymer has a structural unit based on ethyl (meth) acrylate, and the content of the structural unit based on ethyl (meth) acrylate is based on the total amount of the binder polymer and the photopolymerizable compound. The photosensitive resin composition which is less than 9 mass%.   The photosensitive resin composition of Claim 1 in which the said binder polymer further has a structural unit based on styrene or a styrene derivative.   The photosensitive resin composition of Claim 2 whose content of the structural unit based on the said styrene or a styrene derivative is 10-50 mass% with respect to the total mass of the polymerizable monomer which comprises a binder polymer.   The photosensitive resin composition as described in any one of Claims 1-3 in which the said photoinitiator contains the acridine compound which has 1 or 2 an acridinyl group. A photosensitive element comprising a support film and a photosensitive resin composition layer provided on the support film,
The photosensitive element whose said photosensitive resin composition layer is a layer formed using the photosensitive resin composition as described in any one of Claims 1-4. A laminating step of laminating a photosensitive resin composition layer formed using the photosensitive resin composition according to any one of claims 1 to 4 on a substrate;
An exposure step of irradiating the predetermined portion of the photosensitive resin composition layer with an actinic ray to expose and cure the predetermined portion;
A developing step of forming a resist pattern made of a cured product of the photosensitive resin composition on the substrate by removing portions other than the predetermined portion of the photosensitive resin composition layer from the substrate;
A method for forming a resist pattern having   The manufacturing method of a printed wiring board including the process of etching or plating the board | substrate with which the resist pattern was formed by the method of Claim 6.

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