JP2010060891A - Photosensitive resin composition, photosensitive element using the same, method for forming resist pattern and method for manufacturing printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition capable of obtaining a resist pattern excellent particularly in sensitivity, resolution and stripping characteristics of the resist, to provide a photosensitive element using the photosensitive resin composition, and to provide a method for forming a resist pattern and a method for manufacturing a printed wiring board. <P>SOLUTION: The photosensitive resin composition comprises: (A) a binder polymer comprising a copolymer composition having structural units expressed by general formulae (I), (II) and (III); (B) a photopolymerizable compound; and (C) a photopolymerization initiator. The photosensitive element, the method for forming a resist pattern and the method for manufacturing a printed wiring board are achieved by using the above composition. In the formulae, each R<SP>1</SP>independently represents a hydrogen atom or methyl group; each R<SP>2</SP>independently represents 1-3C alkyl group, 1-3C alkoxy group, OH group or a halogen atom; R<SB>3</SB>represents a substituent containing a radical polymerizable unsaturated double bond; and m is an integer from 0 to 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  In the field of manufacturing printed wiring boards, as a resist material used for etching and plating, a photosensitive resin composition and a layer made of this photosensitive resin composition (hereinafter referred to as “photosensitive resin composition layer”) are used. Photosensitive elements (laminates) formed on a support film and having a structure in which a protective film is disposed on a photosensitive resin composition layer are widely used.

  Conventionally, a printed wiring board is manufactured by the following procedure, for example, using the photosensitive element. That is, first, the photosensitive resin composition layer of the photosensitive element is laminated on a circuit forming substrate such as a copper-clad laminate.

  At this time, the surface opposite to the surface of the photosensitive resin composition layer in contact with the support film (hereinafter referred to as the “lower surface” of the photosensitive resin composition layer) (hereinafter referred to as the “upper surface of the photosensitive resin composition layer”). ") In close contact with the surface of the circuit forming substrate on which the circuit is to be formed.

  Therefore, when the protective film is arrange | positioned on the upper surface of the photosensitive resin composition layer, this lamination operation is performed while peeling off the protective film. Next, the photosensitive resin composition layer is thermocompression bonded to the underlying circuit forming substrate (normal pressure laminating method).

Next, pattern exposure is performed through a mask film or the like. At this time, the support film is peeled off at any timing before or after exposure. Thereafter, the unexposed portion is dissolved or dispersed and removed with a developer.
Next, an etching process or a plating process is performed to form a pattern, and finally the cured portion is peeled and removed.

  Here, the etching treatment is a method of removing a resist after etching away a metal surface not covered with a cured resist formed after development. On the other hand, the plating process is a method in which a metal surface not covered with a hardened resist formed after development is subjected to a plating process such as copper and solder, and then the resist is removed and the metal surface covered with the resist is etched. .

  Conventionally, the above-described pattern exposure is performed through a photomask using a mercury lamp as a light source. However, a direct drawing exposure method in which digital data of a pattern is directly drawn on a resist has been proposed. The direct drawing exposure method is being introduced for the production of a high-density package substrate because it has better alignment accuracy than a photomask exposure and can obtain a fine pattern.

  In addition, when using a photosensitive element having the same sensitivity in the direct drawing exposure method, generally, a lot of exposure time is required. Therefore, it is necessary to shorten the exposure time as much as possible in order to improve production throughput. For this purpose, it is necessary to increase the illuminance on the exposure apparatus side, increase the sensitivity of the resist, and the like.

  However, when the conventional photosensitive resin composition is applied to the direct drawing exposure method, the sensitivity, resolution, and resist stripping properties are not sufficient. In order to improve the sensitivity, resolution, and resist release characteristics, various studies have been made on binder resins, photopolymerization initiators, and the like (see, for example, Patent Documents 1 and 2).

  However, even if the photosensitive resin compositions described in Patent Documents 1 and 2 are used, the sensitivity, resolution, and resist stripping characteristics are still insufficient. Since it is important to improve the resolution to reduce the swelling during development as much as possible, in the present invention, the binder polymer side chain is branched with a substituent containing an unsaturated double bond, and not only the crosslinking agent but also the binder polymer. As a result of photocrosslinking, a stronger cross-linking network could be constructed, and swelling during development could be suppressed. As a result, resolution could be improved.

JP 2006-234959 A JP 2005-122123 A

  The present invention relates to a photosensitive resin composition capable of obtaining a resist pattern particularly excellent in sensitivity, resolution, and resist peeling characteristics, a photosensitive element using the same, a method for forming a resist pattern, and a method for producing a printed wiring board. The purpose is to provide.

  The present inventors have (A) a binder polymer comprising a copolymer composition of structural units represented by the following general formulas (I), (II) and (III),

（ここでＲ^１はそれぞれ独立に水素原子又はメチル基を表し、Ｒ^２はそれぞれ独立に炭素数１〜３のアルキル基又はアルコキシ基、ＯＨ基、ハロゲンを表し、Ｒ_３はラジカル重合性不飽和二重結合含有の置換基を示し、ｍは０〜５の整数である。）
（Ｂ）光重合性化合物及び（Ｃ）光重合開始剤を含有する感光性樹脂組成物が、高感度、かつ良好な解像度とレジスト形状を得ることができ、さらに良好な剥離性有することを見出し、本発明を完成するに至った。

(Wherein R ¹ independently represents a hydrogen atom or a methyl group, R ² independently represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group, an OH group, or a halogen, and R ₃ represents radical polymerizable unsaturated). And represents a substituent containing a double bond, and m is an integer of 0 to 5.)
It has been found that a photosensitive resin composition containing (B) a photopolymerizable compound and (C) a photopolymerization initiator can obtain a high sensitivity, good resolution and resist shape, and further has good peelability. The present invention has been completed.

  The present invention comprises (A) a binder polymer comprising a copolymer composition of structural units represented by the following general formulas (I), (II) and (III),

（ここでＲ^１はそれぞれ独立に水素原子又はメチル基を表し、Ｒ^２はそれぞれ独立に炭素数１〜３のアルキル基又はアルコキシ基、ＯＨ基、ハロゲンを表し、Ｒ_３はラジカル重合性不飽和二重結合含有の置換基を示し、ｍは０〜５の整数である。）
（Ｂ）光重合性化合物及び（Ｃ）光重合開始剤を含有してなる感光性樹脂組成物に関する。

(Wherein R ¹ independently represents a hydrogen atom or a methyl group, R ² independently represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group, an OH group, or a halogen, and R ₃ represents radical polymerizable unsaturated). And represents a substituent containing a double bond, and m is an integer of 0 to 5.)
The present invention relates to a photosensitive resin composition comprising (B) a photopolymerizable compound and (C) a photopolymerization initiator.

Moreover, this invention relates to said photosensitive resin composition whose (C) photoinitiator is a hexaaryl biimidazole derivative.
The present invention also relates to a photosensitive resin composition containing (D) a sensitizing dye in addition to any of the photosensitive resin compositions described above.

Moreover, this invention relates to the photosensitive resin composition which contains the (E) amine compound further in the photosensitive resin composition in any one of said.
Moreover, this invention relates to the photosensitive element provided with the photosensitive resin composition layer which consists of a photosensitive resin composition in any one of the above-mentioned formed on the support film and this support film.

  In the present invention, a photosensitive resin composition layer comprising any one of the photosensitive resin compositions described above is laminated on a circuit-forming substrate, and an actinic ray is applied to a predetermined portion of the photosensitive resin composition layer. The resist pattern is formed by exposing the exposed portion to photocuring, and then removing portions other than the exposed portion.

  Furthermore, the present invention relates to a method for manufacturing a printed wiring board, wherein the circuit forming substrate on which the resist pattern is formed is etched or plated by the resist pattern forming method described above.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the photosensitive resin composition which is excellent in a sensitivity, the resolution, and the peeling characteristic of a resist, the photosensitive element using this, the formation method of a resist pattern, and the manufacturing method of a printed wiring board. .

  Hereinafter, the best mode for carrying out the invention will be described in detail. In the present invention, (meth) acrylic acid means acrylic acid or methacrylic acid, (meth) acrylate means acrylate or a corresponding methacrylate, and (meth) acryloyl group means acryloyl group or methacryloyl group. Means.

(Photosensitive resin composition)
First, the photosensitive resin composition used as the constituent material of the photosensitive resin composition layer of the photosensitive element of this invention is demonstrated.

  This photosensitive resin composition is a photosensitive resin composition of a photosensitive element having at least a support film, a protective film made of a synthetic resin, and a photosensitive resin composition layer disposed between the support film and the protective film. A photosensitive resin composition that is a constituent material of a physical layer, and (A) a binder polymer comprising a copolymer composition of structural units represented by the following general formulas (I), (II), and (III):

（ここでＲ^１はそれぞれ独立に水素原子又はメチル基を表し、Ｒ^２はそれぞれ独立に炭素数１〜３のアルキル基又はアルコキシ基、ＯＨ基、ハロゲンを表し、Ｒ_３はラジカル重合性不飽和二重結合含有の置換基を示し、ｍは０〜５の整数である。）
（Ｂ）光重合性化合物及び（Ｃ）光重合開始剤を含有してなる感光性樹脂組成物である。

(Wherein R ¹ independently represents a hydrogen atom or a methyl group, R ² independently represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group, an OH group, or a halogen, and R ₃ represents radical polymerizable unsaturated). And represents a substituent containing a double bond, and m is an integer of 0 to 5.)
A photosensitive resin composition comprising (B) a photopolymerizable compound and (C) a photopolymerization initiator.

First, the binder polymer as component (A) will be described.
From the viewpoint of peeling characteristics and developability of the photosensitive resin composition layer with the photosensitive resin composition as a constituent material from the circuit-forming substrate, the structural unit of the general formula (I) is based on the total mass of the binder polymer molecule. It is preferably 15 to 50% by mass, more preferably 20 to 40% by mass, and particularly preferably 25 to 35% by mass. Examples of the polymerizable monomer having the structural unit of the general formula (I) include (meth) acrylic acid or (meth) acrylic acid derivatives.

  From the viewpoint of improving the adhesion of the resist, the constituent unit of the general formula (II) is preferably 15 to 60% by mass, and preferably 20 to 55% by mass with respect to the total mass of the binder polymer molecule. More preferably, it is 25-50 mass%, and it is especially preferable. Styrene or a styrene derivative is mentioned as a polymerizable monomer made into the structural unit of general formula (II).

  From the viewpoint of improving the adhesion of the resist, the structural unit of the general formula (III) is preferably 0.1 to 30% by mass, and 0.5 to 20% by mass with respect to the total mass of the binder polymer molecule. It is more preferable that it is 1-10 mass%. As a polymerizable monomer as a structural unit of the general formula (III), an adduct of glycidyl (meth) acrylate to (meth) acrylic acid, 2- (2-vinyloxyethoxy) ethyl (meth) acrylate, Examples include adducts to (meth) acrylic acid.

A (meth) acrylic acid alkyl ester or a (meth) acrylic acid hydroxyalkyl ester derivative may be used for the binder polymer. It is 1 to 15% by mass, preferably 2 to 12% by mass, more preferably 3 to 10% by mass, and particularly preferably 4 to 8% by mass with respect to the total mass of the binder polymer molecule. preferable. Examples of the (meth) acrylic acid alkyl ester include compounds represented by the following general formula (IV), compounds in which the alkyl group of these compounds is substituted with a hydroxyl group, an epoxy group, a halogen group, or the like. However, in the following general formula (IV), R ⁴ represents a hydrogen atom or a methyl group, and R ⁵ represents an alkyl group having 1 to 12 carbon atoms or a hydroxyalkyl group.

上記一般式（ＩＶ）中のＲ^５で示される炭素数１〜１２のアルキル基としては、例えば、ベンジル基、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基及びこれらの構造異性体が挙げられる。

Examples of the alkyl group having 1 to 12 carbon atoms represented by R ⁵ in the general formula (IV) include benzyl group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, Examples include octyl group, nonyl group, decyl group, undecyl group, dodecyl group and structural isomers thereof.

  Examples of the monomer represented by the general formula (IV) include (meth) acrylic acid benzyl ester, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, ( (Meth) acrylic acid butyl ester, (meth) acrylic acid pentyl ester, (meth) acrylic acid hexyl ester, (meth) acrylic acid heptyl ester, (meth) acrylic acid octyl ester, (meth) acrylic acid 2-ethylhexyl ester, ( (Meth) acrylic acid nonyl ester, (meth) acrylic acid decyl ester, (meth) acrylic acid undecyl ester, (meth) acrylic acid dodecyl ester, (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2-hydroxy Propyl, 3-hydro (meth) acrylic acid Shipuropiru include (meth) 4-hydroxybutyl acrylic acid. These may be used alone or in any combination of two or more.

  In the binder polymer (A) of the present invention, when the content of the structural unit of the general formula (I) is less than 15% by mass, the alkali solubility is inferior, the peel piece tends to be large, and the peel time tends to be long. If the content exceeds 50% by mass, the resolution tends to decrease.

If the content of the structural unit of the general formula (II) is less than 15% by mass, the resolution tends to be inferior, and if the content exceeds 60% by mass, the peel piece tends to be large and the peel time tends to be long. is there.
Moreover, when content of general formula (III) exceeds 30 mass%, there exists a tendency for peelability to fall.

In the present invention, the “styrene derivative” refers to a compound in which a hydrogen atom in styrene is substituted with a substituent (an organic group such as an alkyl group or a halogen atom).
When forming the photosensitive resin composition layer using this binder polymer, 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 copolymerization components (including different repeating units as constituent components), two or more types of binders having different weight average molecular weights Examples thereof include polymers and 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 weight average molecular weight (Mw) and the number average molecular weight (Mn) of the binder polymer can be measured by gel permeation chromatography (GPC) (converted by a calibration curve using standard polystyrene).

  According to this measurement method, the Mw of the binder polymer is preferably 5000 to 300000, and more preferably 40000 to 150,000. When Mw is less than 5000, the developer resistance tends to decrease, and when it exceeds 300,000, the development time tends to be long.

  The (A) binder polymer preferably has a dispersity (Mw / Mn) of 1.0 to 3.0, and more preferably 1.0 to 2.0. When the degree of dispersion exceeds 3.0, the adhesion and resolution tend to decrease.

  The (A) binder polymer may be used in combination with a styrene resin, an epoxy resin, an amide resin, an amide epoxy resin, an alkyd resin, or a phenol resin.

The (A) binder polymer of the present invention can be produced, for example, by radical polymerization of a polymerizable monomer.
Moreover, (A) binder polymer of this invention can also use together polymerizable monomers other than the polymerizable monomer for comprising the said general formula (I)-(IV).

  Examples of the polymerizable monomer other than the polymerizable monomer for constituting the general formulas (I) to (IV) include, for example, acrylamide such as diacetone acrylamide, acrylonitrile, and vinyl alcohol such as vinyl n-butyl ether. Esters, (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-bromo (meth) acrylic acid, α-chloro (meth) acrylic acid, β-furyl (meth) Acrylic acid, β-styryl (meth) acrylic acid, maleic acid, maleic Anhydride, monomethyl maleate, monoethyl maleate, maleic acid monoesters such as maleic acid monoisopropyl, fumaric acid, cinnamic acid, alpha-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid. These may be used alone or in any combination of two or more.

  The (A) binder polymer in the present invention is preferably composed of one or more kinds of polymers having a carboxyl group from the viewpoint of developability when alkali development is performed using an alkaline solution. Such a (A) binder polymer can be produced, for example, by radical polymerization of a polymerizable monomer having a carboxyl group and another polymerizable monomer.

  (A) It is preferable that the acid value of a binder polymer is 30-200 mgKOH / g, and it is more preferable that it is 45-150 mgKOH / g. When the acid value is less than 30 mg KOH / g, the development time tends to be long, and when it exceeds 200 mg KOH / g, the developer resistance of the photocured resist tends to be lowered.

Moreover, when performing solvent image development as a image development process, it is preferable to prepare the polymerizable monomer which has a carboxyl group in a small quantity.
In addition, (A) the binder polymer may have a characteristic group having photosensitivity in the molecule as necessary.

(A) As content of a binder polymer, it is preferable to set it as 30-70 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, and it is more preferable to set it as 35-65 mass parts. 40 to 60 parts by mass is particularly preferable. If the content is less than 30 parts by mass, a good shape tends not to be obtained, and if it exceeds 70 parts by mass, good sensitivity and resolution tend not to be obtained. Each is used alone or in combination of two or more.

Next, the photopolymerizable compound as the component (B) will be described.
Examples of (B) photopolymerizable compounds include compounds obtained by reacting polyhydric alcohols with α, β-unsaturated carboxylic acids, bisphenol A-based (meth) acrylate compounds, glycidyl group-containing compounds with α, β- Compounds obtained by reacting unsaturated carboxylic acids, urethane monomers such as (meth) acrylate compounds having a urethane bond in the molecule, nonylphenoxypolyethyleneoxyacrylate, phthalic acid compounds, (meth) acrylic acid alkyl esters, etc. It is done. These are used alone or in combination of two or more.

  The (B) photopolymerizable compound preferably contains a bisphenol A-based (meth) acrylate compound or a (meth) acrylate compound having a urethane bond in the molecule as an essential component from the viewpoint of plating resistance and adhesion.

  Also, a photopolymerizable unsaturated compound having one polymerizable ethylenically unsaturated bond in the molecule and a photopolymerizable unsaturated compound having two or more polymerizable ethylenically unsaturated bonds in the molecule. Use in combination is preferable from the viewpoint of obtaining the effect of the present invention more reliably.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 2 propylene groups. 14 polypropylene glycol di (meth) acrylate, 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, tetramethylolmethanetri (meta ) Acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like. These may be used alone or in combination of two or more.

Here, “EO” represents ethylene oxide, and an EO-modified compound represents one having a block structure of an ethylene oxide group.
“PO” represents propylene oxide, and a PO-modified compound has a propylene oxide group block structure.

  Examples of the bisphenol A-based (meth) acrylate compound include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolypropoxy). Phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane and the like It is done.

  Examples of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2 -Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meta ) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) Propane, 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxynonane) Xyl) phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, 2 , 2-bis (4-((meth) acryloxydodecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4- ((Meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy) Hexadecaethoxy) phenyl) propane and the like.

  2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is BPE-500 (made by Shin-Nakamura Chemical Co., Ltd., trade name), FA-321M (made by Hitachi Chemical Co., Ltd., trade name) 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). It is available.

  The number of ethylene oxide groups in one molecule of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane is preferably 4-20, and more preferably 8-15. . These may be used alone or in any combination of two or more.

  Examples of the (meth) acrylate compound having a urethane bond in the molecule include, for example, a (meth) acryl monomer having an OH group at the β-position and a diisocyanate compound (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, EO, PO-modified urethane di (meth) acrylate Etc.

Examples of the EO-modified urethane di (meth) acrylate include UA-11 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.).
Examples of the EO and PO-modified urethane di (meth) acrylate include UA-13 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). These may be used alone or in combination of two or more.

  Examples of the nonylphenoxypolyethyleneoxyacrylate include nonylphenoxytetraethyleneoxyacrylate, nonylphenoxypentaethyleneoxyacrylate, nonylphenoxyhexaethyleneoxyacrylate, nonylphenoxyheptaethyleneoxyacrylate, nonylphenoxyoctaethyleneoxyacrylate, nonylphenoxynonaethylene Examples include oxyacrylate, nonylphenoxydecaethyleneoxyacrylate, and nonylphenoxyundecaethyleneoxyacrylate. These may be used alone or in any combination of two or more.

  Examples of the phthalic acid compounds include γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloloxyalkyl-o-phthalate. Etc. These may be used alone or in any combination of two or more.

  The component (B) of the present invention preferably contains a bisphenol A (meth) acrylate compound from the viewpoint of improving sensitivity and resolution. From the viewpoint of shortening the peeling time, one ethylenically unsaturated group is contained in the molecule. It is preferable that the compound which has this is included.

  In addition, the component (B) of the present invention contains polyalkylene glycol di (meth) acrylate having both an ethylene glycol chain and a propylene glycol chain in the molecule from the viewpoint of improving the flexibility of the cured film. Is preferred.

  This (meth) acrylate is not particularly limited as long as it has both an ethylene glycol chain and a propylene glycol chain (n-propylene glycol chain or isopropylene glycol chain) as alkylene glycol chains in the molecule.

  In addition, this (meth) acrylate further includes an n-butylene glycol chain, an isobutylene glycol chain, an n-pentylene glycol chain, a hexylene glycol chain, an alkylene glycol chain having about 4 to 6 carbon atoms such as a structural isomer thereof. You may have.

When there are a plurality of ethylene glycol chains and propylene glycol chains, the plurality of ethylene glycol chains and propylene glycol chains need not be continuously present in blocks, and may be present randomly.
In the isopropylene glycol chain, the secondary carbon of the propylene group may be bonded to an oxygen atom, or the primary carbon may be bonded to an oxygen atom.

  Intramolecular of polyalkylene glycol di (meth) acrylate having at least one polymerizable ethylenically unsaturated bond in these components (B) and having both ethylene glycol chain and propylene glycol chain in the molecule The alkylene glycol chain of, for example, general formula (V):

（式中、２つのＲは各々独立に水素原子又は炭素数１〜３のアルキル基を示し、ＥＯはエチレングリコール鎖を示し、ＰＯはプロピレングリコール鎖を示し、ｍ^１、ｍ^２及びｎ^１は各々独立に１〜３０の整数である）で表される化合物、一般式（ＶＩ）：

(In the formula, two R's each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, EO represents an ethylene glycol chain, PO represents a propylene glycol chain, and m ¹ , m ² and n ¹ are A compound represented by the general formula (VI): each independently an integer of 1 to 30:

（式中、２つのＲは各々独立に水素原子又は炭素数１〜３のアルキル基を示し、ＥＯはエチレングリコール鎖を示し、ＰＯはプロピレングリコール鎖を示し、ｍ^３、ｎ^２及びｎ^３は各々独立に１〜３０の整数である）で表される化合物、及び一般式（ＶＩＩ）：

(In the formula, two Rs each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, EO represents an ethylene glycol chain, PO represents a propylene glycol chain, and m ³ , n ² and n ³ are Each independently represents an integer of 1 to 30), and general formula (VII):

（式中、２つのＲは各々独立に水素原子又は炭素数１〜３のアルキル基を示し、ＥＯはエチレングリコール鎖を示し、ＰＯはプロピレングリコール鎖を示し、ｍ^４及びｎ^４は各々独立に１〜３０の整数である）で表される化合物等が挙げられる。
これらは単独で又は２種類以上を組み合わせて使用される。

(In the formula, two Rs each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, EO represents an ethylene glycol chain, PO represents a propylene glycol chain, and m ⁴ and n ⁴ each independently represent A compound represented by 1) to 30).
These may be used alone or in combination of two or more.

Examples of the alkyl group having 1 to 3 carbon atoms in the general formulas (V), (VI), and (VII) include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group.
The total number of repeating ethylene glycol chains (m ¹ + m ² , m ³ and m ⁴ ) in the above general formulas (V), (VI) and (VII) is each independently an integer of 1 to 30. Is preferably an integer of 4 to 9, more preferably an integer of 5 to 8. If the number of repetitions exceeds 30, the tent reliability and the resist shape tend to deteriorate.

The total number of repeating propylene glycol chains (n ¹ , n ² + n ³ and n ⁴ ) in the above general formulas (V), (VI) and (VII) is each independently an integer of 1 to 30, Is preferably an integer of 8 to 16, more preferably an integer of 8 to 16, and particularly preferably an integer of 10 to 14. If the number of repetitions exceeds 30, the resolution deteriorates and sludge tends to be generated.

Specific examples of the compound represented by the general formula (V) include, for example, a vinyl compound (Hitachi Chemical Co., Ltd.) in which R = methyl group, m ¹ + m ² = 4 (average value), and n ¹ = 12 (average value). Kogyo Co., Ltd. product name FA-023M).

Specific examples of the compound represented by the general formula (VI) include, for example, a vinyl compound (Hitachi Chemical Co., Ltd.) in which R = methyl group, m ³ = 6 (average value), and n ² + n ³ = 12 (average value). Kogyo Co., Ltd. product name FA-024M).

Specific examples of the compound represented by the general formula (VII) include, for example, R = hydrogen atom, m ⁴ = 1 (average value), n ⁴ = 9 (average value) vinyl compound (Shin Nakamura Chemical Co., Ltd.) Co., Ltd., sample name NK ester HEMA-9P) and the like. These may be used alone or in combination of two or more.

  As content of the photopolymerizable compound of (B) component, it is preferable to set it as 30-70 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, and it is set as 35-65 mass parts. It is more preferable that the amount be 40 to 60 parts by mass. If the content is less than 30 parts by mass, good sensitivity and resolution tend not to be obtained, and if it exceeds 70 parts by mass, a good shape tends not to be obtained. Each is used alone or in combination of two or more.

  Next, as the photopolymerization initiator which is the component (C), for example, 4,4′-bis (diethylamino) benzophenone, benzophenone, 2-benzyldimethylamino-1- (4-morpholinophenyl) -butanone-1, Aromatic ketones such as 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, quinones such as alkylanthraquinone, benzoin ether compounds such as benzoin alkyl ether, benzoin, alkylbenzoin and the like Benzoin compounds, benzyl derivatives such as benzyldimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer 2- (o-fluorophenyl) -4,5-diphenyl 2,4,5- such as imidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer And acridine derivatives such as triarylimidazole dimer, 9-phenylacridine, 1,7-bis (9,9′-acridinyl) heptane, and the like.

Moreover, the substituents of the aryl groups of two 2,4,5-triarylimidazoles may give the same and symmetric compounds, or differently give asymmetric compounds.
From the viewpoint of adhesion and sensitivity, 2,4,5-triarylimidazole dimer is more preferable. These are used alone or in combination of two or more.

  As content of the photoinitiator of (C) component, it is preferable to set it as 0.1-10 mass parts with respect to 100 parts of total amounts of (A) component and (B) component, It is more preferable to use 3.5 to 5 parts by mass. If this content is less than 0.1 parts by mass, good sensitivity and resolution tend not to be obtained, and if it exceeds 10 parts by mass, a good shape tends not to be obtained. Each is used alone or in combination of two or more.

  The sensitizing dye of component (D) in the present invention can effectively utilize the absorption wavelength of the active light to be used. As the sensitizing dye, a compound having a maximum absorption wavelength of 370 nm to 420 nm is preferable.

  In the present invention, by using such a sensitizing dye, it becomes possible to have a sufficiently high sensitivity to the exposure light of the direct drawing exposure method. If the maximum absorption wavelength of the sensitizing dye is less than 370 nm, the sensitivity to direct drawing exposure light tends to decrease, and if it is 420 nm or more, the stability tends to decrease even in a yellow light environment.

  Examples of the sensitizing dye (D) of the present invention include pyrazolines, anthracenes, coumarins, xanthones, oxazoles, benzoxazoles, thiazoles, benzothiazoles, triazoles, stilbenes, triazines, and thiophenes. And naphthalimides.

  (D) The content of the sensitizing dye is preferably 0.01 to 10 parts by mass, and 0.05 to 5 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). More preferably, the content is 0.1 to 2 parts by mass. If this amount is less than 0.01 parts by mass, good sensitivity and resolution tend not to be obtained, and if it exceeds 10 parts by mass, a good shape tends not to be obtained. These may be used alone or in combination of two or more.

  Examples of (E) amine compounds include bis [4- (dimethylamino) phenyl] methane, bis [4- (diethylamino) phenyl] methane, and leucocrystal violet.

  (E) The content of the amine compound is preferably 0.01 to 10 parts by mass, and 0.05 to 5 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). More preferably, the content is 0.1 to 2 parts by mass. If the blending amount is less than 0.01 parts by mass, good sensitivity tends not to be obtained, and if it exceeds 10 parts by mass, there is a tendency to deposit as foreign matter after film formation. These may be used alone or in combination of two or more.

  If necessary, the photosensitive resin composition may include a photopolymerizable compound (such as an oxetane compound) having at least one cationically polymerizable cyclic ether group in the molecule, a cationic polymerization initiator, a dye such as malachite green, Photochromic agents such as bromophenylsulfone and leucocrystal violet, thermochromic inhibitors, plasticizers such as p-toluenesulfonamide, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion promoters, leveling agents , Peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, and the like can be contained in an amount of about 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of component (A) and component (B). . These are used alone or in combination of two or more.

  The photosensitive resin composition of the present invention is 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 mixed solvent thereof. It is good also as a solution about 30-60 mass% of solid content. This solution can be used as a coating solution for forming the photosensitive resin composition layer of the photosensitive element.

  In addition, the above coating solution may be used to form a photosensitive resin composition layer of a photosensitive element by coating and drying on a support film described later, but the surface of a metal plate, for example, copper, Use as a liquid resist on the surface of an iron-based alloy such as a copper-based alloy, nickel, chromium, iron, and stainless steel, preferably copper, copper-based alloy, and iron-based alloy. Also good.

  Moreover, although the layer thickness of the photosensitive resin composition layer changes with uses of the photosensitive element, it is preferable that it is about 1-100 micrometers by the thickness after drying. In the case where the above-described liquid resist is used after being coated with a protective film, examples of the protective film include polymer films such as polyethylene and polypropylene.

(Photosensitive element)
Next, the photosensitive element of the present invention will be described.
The photosensitive element of this invention has a support film, the protective film which consists of synthetic resins, and the photosensitive resin composition layer arrange | positioned between a support film and a protective film at least.

  As the support film, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used. The support film (polymer film) preferably has a thickness of 1 to 100 μm. If the thickness is less than 5 μm, the support film tends to be easily broken when the support film is peeled off before development, and if it exceeds 100 μm, the resolution tends to decrease. One polymer film is used as a support for the photosensitive resin composition layer, and the other is used as a protective film for the photosensitive resin composition, laminated on both sides of the photosensitive resin composition layer. Also good.

  The protective film preferably has a smaller adhesive force between the photosensitive resin composition layer and the protective film than the adhesive force between the photosensitive resin composition layer and the support, and is preferably a low fisheye film. "Fish eye" means that when a material is melted by heat, kneaded, extruded, biaxially stretched, casting method, etc., foreign materials, undissolved materials, oxidized degradation products, etc. It is taken in.

  As the protective film, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used. Examples of commercially available products include polyethylene terephthalate films such as Alphan MA-410 and E-200C manufactured by Oji Paper Co., Ltd., polypropylene films manufactured by Shin-Etsu Film Co., Ltd., and PS series such as PS-25 manufactured by Teijin Limited. Is not limited to this.

  The protective film preferably has a thickness of 1 to 100 μm, more preferably 5 to 50 μm, still more preferably 5 to 30 μm, and particularly preferably 15 to 30 μm. If the thickness is less than 1 μm, the protective film tends to be broken during lamination, and if it exceeds 100 μm, the cost tends to be inferior.

  The photosensitive resin composition layer is prepared by dissolving the photosensitive resin composition of the present invention in a solvent as described above to obtain a solution (coating solution) having a solid content of about 30 to 60% by mass, and then applying the solution (coating solution). (Liquid) is preferably applied on a support film and dried.

The coating can be performed by a known method such as a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, or a bar coater.
Drying can be performed at 70 to 150 ° C. for about 5 to 30 minutes.
Moreover, it is preferable that the amount of the residual organic solvent in the photosensitive resin composition shall be 2 mass% or less from the point which prevents the spreading | diffusion of the organic solvent in a next process.

  Moreover, although the thickness of the photosensitive resin composition layer changes with uses, it is preferable that it is 1-100 micrometers by the thickness after drying, and it is more preferable that it is 1-50 micrometers. If the thickness is less than 1 μm, it tends to be difficult to apply industrially, and if it exceeds 100 μm, the effect of the present invention is reduced, and the adhesive force and resolution tend to decrease.

  Moreover, it is preferable that the transmittance | permeability with respect to the ultraviolet-ray with a wavelength of 365 nm is 5 to 75%, as for the photosensitive resin composition layer, it is more preferable that it is 7 to 60%, and it is especially preferable that it is 10 to 40%. If the transmittance is less than 5%, the adhesion tends to be inferior, and if it exceeds 75%, the resolution tends to be inferior. The transmittance can be measured by a UV spectrometer, and examples of the UV spectrometer include a 228A type W beam spectrophotometer manufactured by Hitachi, Ltd.

  The photosensitive element of the present invention may further have an intermediate layer such as a cushion layer, an adhesive layer, a light absorption layer, and a gas barrier layer. Moreover, the obtained photosensitive element can be wound up and stored in a roll shape around a sheet shape or a core. At this time, it is preferable that the support is wound up so as to be the outermost side.

An end face separator is preferably installed on the end face of the roll-shaped photosensitive element roll from the viewpoint of end face protection, and a moisture-proof end face separator is preferably installed from the viewpoint of edge fusion resistance.
Moreover, as a packing method, it is preferable to wrap and package in a black sheet with low moisture permeability.

  Examples of the winding core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

(Method for forming resist pattern)
Next, the resist pattern forming method of the present invention will be described.
The method for forming a resist pattern of the present invention is a method of gradually removing the protective film of the above-described photosensitive element of the present invention from the photosensitive resin composition layer, and simultaneously exposing the photosensitive resin composition layer that is gradually exposed. A first step of laminating the photosensitive resin composition layer on the circuit forming substrate by bringing the surface portion into close contact with the surface of the circuit forming substrate on which the circuit is to be formed; and exposure of the photosensitive resin composition layer It includes at least a second step of irradiating a predetermined portion to be irradiated with actinic rays to form an exposed portion, and then a third step of removing an unexposed portion other than the exposed portion. It is. The “circuit forming substrate” refers to a substrate including an insulating layer and a conductor layer formed on the insulating layer.

  As a method of laminating the photosensitive resin composition layer on the circuit forming substrate in the first step, after removing the protective film, the photosensitive resin composition layer is used for circuit formation while heating the photosensitive resin composition layer. The method of laminating | stacking by crimping | bonding to a board | substrate is mentioned. In addition, it is preferable to laminate | stack this operation under pressure reduction from the viewpoint of adhesiveness and followable | trackability.

In the lamination of the photosensitive element, the photosensitive resin composition layer and / or the circuit forming substrate is preferably heated to 70 to 130 ° C., and the pressure bonding pressure is about 0.1 to 1.0 MPa (1 to 10 kgf / cm). it is preferably about ^2), but not particularly limited to these conditions.

  Further, if the photosensitive resin composition layer is heated to 70 to 130 ° C. as described above, it is not necessary to pre-heat the circuit forming substrate in advance, but in order to further improve the laminating property, Pre-heat treatment of the substrate can also be performed.

  Examples of the method for forming the exposed portion in the second step include a method of irradiating an image with active light through a negative or positive mask pattern called an artwork (mask exposure method).

At this time, when the support film present on the photosensitive resin composition layer is transparent to the active light, the active light can be irradiated through the support film, and when the support film is light-shielding After removing the support film, the photosensitive resin composition layer is irradiated with actinic rays.
Further, a method of irradiating actinic rays in an image form by a direct drawing method such as a laser direct drawing exposure method or a DLP (Digital Light Processing) exposure method may be adopted.

  As a light source of actinic light, known light sources such as carbon arc lamps, mercury vapor arc lamps, high pressure mercury lamps, xenon lamps, gas lasers such as argon lasers, solid state lasers such as YAG lasers, ultraviolet rays such as semiconductor lasers, visible light, etc. That effectively radiate are used.

  Next, after the exposure, as a method of removing the portion other than the exposed portion in the third step, first, when the support film is present on the photosensitive resin composition layer, the support film is removed, and then Examples include a method in which a portion other than the exposed portion is removed by wet development, dry development, or the like. Thereby, a resist pattern is formed.

  For example, in the case of wet development, using a developer corresponding to a photosensitive resin composition such as an alkaline aqueous solution, an aqueous developer, an organic solvent developer, etc., for example, spraying, rocking immersion, brushing, scraping, etc. Development is performed by a known method.

  As the developing solution, a safe and stable solution having good operability such as an alkaline aqueous solution is used. 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, and phosphoric acid. Alkali metal phosphates such as sodium and alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate are used.

Moreover, as alkaline aqueous solution used for image development, 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, A dilute solution of 0.1 to 5% by mass sodium tetraborate is preferred.
The pH of the alkaline aqueous solution used for development is preferably in the range of 9 to 11, and the temperature is adjusted according to the developability of the photosensitive resin composition layer.
Further, in the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like may be mixed.

  Examples of the aqueous developer include a developer composed of water or an alkaline aqueous solution and one or more organic solvents. Here, as the base of the alkaline aqueous solution, in addition to the substances described above, for example, borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1, Examples include 3-propanediol, 1,3-diaminopropanol-2, morpholine and the like. The pH of the developer is preferably as low as possible within a range where the resist can be sufficiently developed, preferably pH 8-12, more preferably pH 9-10.

  Examples of the organic solvent include acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and the like. It is done. These are used alone or in combination of two or more.

The concentration of the organic solvent is usually preferably 2 to 90% by mass, and the temperature can be adjusted according to the developability.
Further, a small amount of a surfactant, an antifoaming agent or the like can be mixed in the aqueous developer. Examples of the organic solvent developer used alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone.

These organic solvents preferably add water in the range of 1 to 20% by mass in order to prevent ignition.
Moreover, you may use together 2 or more types of image development methods as needed. Development methods include a dip method, a battle method, a spray method, brushing, and slapping, and the high pressure spray method is most suitable for improving the resolution.

Examples of the development method include a dip method, a spray method, brushing, and slapping. As the treatment after development, the resist pattern may be further cured and used by heating at about 60 to 250 ° C. or exposure at about 0.2 to 10 J / cm ² as necessary.
For the etching of the metal surface performed after development, for example, a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, or the like can be used.

(Printed wiring board manufacturing method)
Next, the manufacturing method of the printed wiring board of this invention is demonstrated. The method for producing a printed wiring board of the present invention comprises etching or plating a circuit forming substrate on which a resist pattern is formed by the method for forming a resist pattern of the present invention.

  Etching and plating of the circuit forming substrate is performed on a conductor layer or the like of the circuit forming substrate using the formed resist pattern as a mask. Etching solutions used for etching include cupric chloride solution, ferric chloride solution, alkaline etching solution, and hydrogen peroxide etching solution. It is preferable to use an iron solution.

  Moreover, as a plating method in the case of plating, for example, 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 sulfamate, etc. Nickel plating, hard gold plating, and gold plating such as soft gold plating.

  After completion of the etching or plating, 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.

Examples of the peeling method include a dipping method and a spray method, and the dipping method and the spray method 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. A printed wiring board is obtained as described above.

Hereinafter, preferred examples of the present invention will be described in more detail, but the present invention is not limited to these examples.
[Synthesis of Binder Polymer (A-1)]
To a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen gas introduction pipe, add 300 g of propylene glycol monomethyl ether and toluene in a mass ratio of 3: 2, and stir while blowing nitrogen gas. And heated to 80 ° C.

  On the other hand, 81 g (0.92 mmol) of methacrylic acid, 75 g (0.72 mmol) of methyl methacrylate, 69 g (0.39 mmol) of benzyl methacrylate and 75 g (0.75 mmol) of styrene as comonomer, azobisisobuty A solution (hereinafter referred to as “solution a”) prepared by mixing 1.5 g of nitrile is prepared, and the solution a is added to the above mixture of propylene glycol monomethyl ether and toluene having a mass ratio of 3: 2 heated to 80 ° C. After dropwise addition over 4 hours, the mixture was kept warm at 80 ° C. for 2 hours with stirring.

  Furthermore, a solution in which 0.5 g of azobisisobutyronitrile was dissolved in 25 g of a mixture of propylene glycol monomethyl ether and toluene (solid content concentration: 48%) having a mass ratio of 3: 2 was placed in the flask over 10 minutes. It was dripped. The solution after dropping was kept at 80 ° C. for 3 hours with stirring, and then heated to 90 ° C. over 30 minutes. After incubating at 90 ° C. for 2 hours, the mixture was cooled to 60 ° C.

  Next, 14.9 g (0.1 mmol) of glycidyl methacrylate was added while nitrogen gas was stopped and air bubbles were performed, and the mixture was stirred for 6 hours to obtain a binder polymer (A-1). The nonvolatile content (solid content) of the binder polymer (A-1) was 47.8% by mass, and the weight average molecular weight was 41,000. The weight average molecular weight was measured by a gel permeation chromatography method and was 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.]
Column: Gelpack GL-R420 + Gelpack GL-R430 + Gelpack GL-R440 (3 in total) (above, manufactured by Hitachi Chemical Co., Ltd., trade name)
Eluent: Tetrahydrofuran Measurement temperature: 40 ° C
Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI [manufactured by Hitachi, Ltd.]

[Synthesis of Binder Polymers (A-2) to (A-6)]
Binder polymers (A-2) to (A-6) were synthesized in the same manner as the binder polymer (A-1) with the following comonomer composition.

(B) Photopolymerizable compound (B-1): FA-321M (manufactured by Hitachi Chemical Co., Ltd., trade name); 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane (B-2) ): FA-024M (trade name, manufactured by Hitachi Chemical Co., Ltd.); in the compound represented by the general formula (VI), R = methyl group, m ³ = 6 (average value), n ² + n ³ = 12 (mean value))
(B-3): M-114 (trade name, manufactured by Toagosei Co., Ltd.); 4-normalnonylphenoxyoctaethylene glycol acrylate

(C) Photopolymerization initiator (C-1): BCIM (trade name, manufactured by Hampford ); 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbisimidazole ( D) Sensitizing dye DBA: (trade name, manufactured by Kawasaki Kasei Kogyo Co., Ltd.); 9,10-dibutoxyanthracene (E) color former (amine compound)
Leuco crystal violet

＊ 固形分量

* Solid content

  Next, the solution of the photosensitive resin composition was uniformly applied onto a 16 μm thick polyethylene terephthalate film and dried by a hot air convection dryer at 70 ° C. and 110 ° C. to obtain a photosensitive element. The film thickness of the photosensitive resin composition layer was 25 μm.

  On the other hand, the copper surface of a copper clad laminate (made by Hitachi Chemical Co., Ltd., trade name MCL-E-67), which is a glass epoxy material laminated with copper foil (thickness 35 mm) on both sides, is a brush equivalent to # 600. Polishing was performed using a polishing machine (manufactured by Sankei Co., Ltd.), washed with water, and dried with an air stream to obtain a copper clad laminate (substrate).

Then, after heating to copper clad laminate 80 ° C., each photosensitive resin composition (each photosensitive resin composition while removing the protective films of Examples 1 to 6 and Comparative Examples 1 and 2 on the copper clad laminate) The layer was laminated (laminated) at 120 ° C. under a pressure of 4 kgf / cm ² so that the layer adhered to the surface of the copper-clad laminate.

  Next, when the copper clad laminate on which each photosensitive element is laminated is cooled to 23 ° C., the polyethylene terephthalate surface has a concentration region of 0.00 to 2.00, a concentration step of 0.05, and a tablet size. A phototool having a 41-step tablet having a length of 20 mm × 187 mm and a size of each step of 3 mm × 12 mm was adhered.

Using a direct drawing machine DE-1AH manufactured by Hitachi Via Mechanics Co., Ltd. using a 405 nm blue-violet laser diode as a light source, direct drawing was performed with a predetermined exposure amount, and the number of remaining step steps after development of the 41-step tablet was determined.
Further, a drawing pattern having a line width / space width of 6/6 to 22/22 (unit: mm) was used, and after development, the minimum dimension at which the resolution density was obtained was defined as the resolution.

The number of remaining steps when 50 mJ / cm ² was exposed was shown as sensitivity. The illuminance was measured using an ultraviolet illuminometer (trade name: “UIT-150” manufactured by USHIO INC.) To which a 405 nm probe was applied.

  Next, the polyethylene terephthalate film was peeled off, and a 1% by mass sodium carbonate aqueous solution was sprayed at 30 ° C. for 24 seconds to remove unexposed portions. Then, the photosensitivity of the photosensitive resin composition was evaluated by measuring the number of steps of the step tablet of the photocured film formed on the copper-clad laminate. The results are shown in Table 4 below. The photosensitivity is indicated by the number of steps of the step tablet, and the higher the number of steps of the step tablet, the higher the photosensitivity.

  Resolution adhesion was evaluated based on the smallest value of equal width lines / spaces in which unexposed portions could be removed cleanly by development processing, and the lines were generated without meandering or chipping. The evaluation of sensitivity and resolution is better as the numerical value is smaller. The results are also shown in Table 4 below.

The resist shape after development was observed using a Hitachi scanning electron microscope S-500A. The resist shape is preferably close to a rectangle.
For the peelability, a photocured film having a size of 40 mm × 50 mm was prepared under the conditions shown in Table 3, and peeling was performed using a 3% by mass aqueous sodium hydroxide solution. The time when the film finished peeling from the substrate was defined as the peeling time. Moreover, the size of the peeling piece after peeling completion was observed visually (S; it shows that a peeling piece is small).

＊ 露光量８０ｍＪ／ｃｍ^２でのステップ段数

* Number of steps at exposure 80mJ / cm ²

  As shown in Table 4, in the compositions of Examples 1 to 6, the resolution adhesion (L / S) is as high as 10 μm, the peeling time is moderately short, the peeling piece size is small, and the resolution is high. It is clear that the peelability is balanced. On the other hand, in Comparative Examples 1-2, although the peelability was good, the resolution was low.

Claims (7)

(A) a binder polymer comprising a copolymer composition of structural units represented by the following general formulas (I), (II) and (III);

(Wherein R ¹ independently represents a hydrogen atom or a methyl group, R ² independently represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group, an OH group, or a halogen, and R ₃ represents radical polymerizable unsaturated). And represents a substituent containing a double bond, and m is an integer of 0 to 5.)
A photosensitive resin composition comprising (B) a photopolymerizable compound and (C) a photopolymerization initiator.   (C) The photosensitive resin composition of Claim 1 whose photoinitiator is a hexaaryl biimidazole derivative.   A photosensitive resin composition further comprising (D) a sensitizing dye in the photosensitive resin composition according to claim 1.   A photosensitive resin composition further comprising (E) an amine compound in the photosensitive resin composition according to claim 1, 2 or 3.   The photosensitive element provided with the photosensitive resin composition layer which consists of a photosensitive resin composition of Claim 1, 2, 3 or 4 formed on the support film and this support film.   A photosensitive resin composition layer comprising the photosensitive resin composition according to claim 1, 2, 3, 4, or 5 is laminated on a circuit forming substrate, and active light is applied to a predetermined portion of the photosensitive resin composition layer. Is applied to photocure the exposed portion, and then the portion other than the exposed portion is removed.   A method for manufacturing a printed wiring board, comprising etching or plating a circuit forming substrate on which a resist pattern is formed by the method for forming a resist pattern according to claim 6.