JP2014134815A - Photosensitive resin composition, photosensitive element, method for forming resist pattern, and method for manufacturing printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition having a sufficient effect on improvement in resolution and resist stripping characteristics.SOLUTION: The photosensitive resin composition comprises: (A) a binder polymer having a structural unit based on styrene or a styrene derivative, a structural unit based on a (meth)acrylic acid benzyl or a (meth)acrylic acid benzyl derivative, a structural unit based on a (meth)acrylic acid, and a structural unit based on a (meth)acrylic acid alkyl ester, and having a dispersion degree of 1.0 to 2.0; (B) a photopolymerizable compound; and (C) a photopolymerization initiator. The (A) binder polymer further includes at least one of a structural unit based on a (meth)acrylic acid 2-ethylhexyl ester and a structural unit based on a (meth)acrylic acid dodecyl ester.

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, as a resist material used for etching or plating, a photosensitive resin composition or a layer containing the photosensitive resin composition (hereinafter referred to as “photosensitive resin composition layer”). A photosensitive element (laminate) having a structure in which is formed on a support film and a protective film is disposed on the photosensitive resin composition layer is 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”). ") Is in close contact with the surface of the circuit forming substrate on which the circuit is 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. Lamination is performed by thermocompression bonding the photosensitive resin composition layer to the underlying circuit-forming substrate (normal pressure laminating method).

  Next, the photosensitive resin composition layer is subjected to pattern exposure through a mask film or the like. At this time, the support film is peeled off at any timing before or after exposure. Then, the unexposed part of the photosensitive resin composition layer 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 the cured resist after etching away the metal surface of the circuit forming substrate not covered with the cured resist formed after development. On the other hand, the plating treatment is that the metal surface of the circuit forming substrate that is not covered with the cured resist formed after development is plated with copper and solder, and then the cured resist is removed and covered with this resist. This is a method of etching a metal surface.

  By the way, as the above-described pattern exposure technique, a technique of exposing via a photomask using a mercury lamp as a light source is conventionally used. In recent years, as a new exposure technique, a direct drawing exposure method called DLP (Digital Light Processing), which directly draws digital data of a pattern on a photosensitive resin composition layer, has been proposed. This direct drawing exposure method is being introduced for the production of a high-density package substrate because the alignment accuracy is better than the exposure method through a photomask and a fine pattern can be obtained.

  In pattern exposure, it is necessary to shorten the exposure time as much as possible in order to improve production throughput. In the direct drawing exposure method described above, if a composition having the same sensitivity as that of the photosensitive resin composition used in the conventional exposure method via a photomask is used, generally a lot of exposure time is required. Therefore, it is necessary to increase the illuminance on the exposure apparatus side and increase the sensitivity of the photosensitive resin composition.

  In addition to the sensitivity described above, it is important that the photosensitive resin composition is excellent in resolution and resist peeling characteristics. If the photosensitive resin composition can provide a resist pattern with excellent resolution, it is possible to sufficiently reduce short circuits and disconnections between circuits. In addition, if the photosensitive resin composition can form a resist with excellent peeling characteristics, the resist patterning efficiency is improved by shortening the resist peeling time, and the size of the resist peeling pieces By reducing, the resist peeling residue is reduced and the yield of circuit formation is improved. A photosensitive resin composition having excellent sensitivity, resolution, and resist release characteristics using a specific binder polymer, a photopolymerization initiator, and the like has been proposed for such a demand (see, for example, Patent Documents 1 and 2). ).

JP 2006-234959 A JP 2005-122123 A

  However, the photosensitive resin compositions described in Patent Documents 1 and 2 have not been sufficient in resolution and resist stripping characteristics.

  Therefore, an object of the present invention is to provide a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for producing a printed wiring board, which are sufficiently effective in improving resolution and resist stripping characteristics.

  In order to solve the above-mentioned problems, the inventors of the present invention have made extensive studies focusing on the composition of the binder polymer. As a result, it has been found that by using a binder polymer having a specific structure, a photosensitive resin composition that is sufficiently effective in improving the resolution and resist stripping properties can be obtained, and the present invention has been completed.

ここで、式（Ｉ）、式（ＩＩ）、式（ＩＩＩ）、及び式（ＩＶ）中、Ｒ^１，Ｒ^３，Ｒ^５，及びＲ^６はそれぞれ独立に水素原子又はメチル基を示し、Ｒ^２及びＲ^４はそれぞれ独立に炭素数１〜３のアルキル基、炭素数１〜３のアルコキシ基、ＯＨ基、又はハロゲン原子を示し、Ｒ^７は炭素数１〜６のアルキル基を示し、ｍ又はｎはそれぞれ独立に０〜５の整数を示し、ｍ又はｎが２〜５のとき、複数のＲ^２又はＲ^４は互いに同一でも異なっていてもよい。 The photosensitive resin composition of the present invention comprises (A) a divalent group represented by general formula (I) (hereinafter also referred to as “structural unit”) and a divalent group represented by general formula (II). A binder polymer having a group, a divalent group represented by the general formula (III), and a divalent group represented by the general formula (IV), (B) a photopolymerizable compound, and (C) Contains a photopolymerization initiator.

Here, in formula (I), formula (II), formula (III), and formula (IV), R ¹ , R ³ , R ⁵ , and R ⁶ each independently represent a hydrogen atom or a methyl group, and R ² and R ⁴ each independently represent an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an OH group, or a halogen atom, R ⁷ represents an alkyl group having 1 to 6 carbon atoms, m or n is independently an integer of 0 to 5, when m or n is 2 to 5, a plurality of R ² or R ⁴ may be the same or different from each other.

  Moreover, as for the photosensitive resin composition of this invention, it is preferable that (C) photoinitiator has a hexaaryl biimidazole compound. Thereby, the sensitivity of the photosensitive resin composition and the adhesiveness of the resist are improved.

  Moreover, it is preferable that the photosensitive resin composition of this invention further contains (D) sensitizing dye. Thereby, when exposing with the light which has a peak in a specific wavelength range, maximum absorption can be given near the specific wavelength range, and the sensitivity of the photosensitive resin composition is improved.

  Moreover, it is preferable that the photosensitive resin composition of this invention further contains (E) amine compound. Thereby, the sensitivity of the photosensitive resin composition is further enhanced.

  Moreover, this invention is a photosensitive element provided with a support film and the photosensitive resin composition layer containing the said photosensitive resin composition formed on the said support film. According to this support film, since the photosensitive resin composition layer containing the photosensitive resin composition is provided, even when a resist pattern is formed by a direct drawing exposure method, it can be performed with sufficient resolution. is there. In addition, it is sufficiently effective in improving the resist peeling characteristics.

  The present invention also provides a lamination step of laminating a photosensitive resin composition layer containing the photosensitive resin composition on a circuit-forming substrate, and irradiating a predetermined portion of the photosensitive resin composition layer with actinic rays. A resist pattern forming method comprising: an exposure step of photocuring an exposed portion; and a developing step of removing a portion other than the exposed portion of the photosensitive resin composition layer from the circuit forming substrate on which the photosensitive resin composition layer is laminated. is there. According to this resist pattern forming method, since the resist pattern is formed using the photosensitive resin composition layer containing the photosensitive resin composition, the direct drawing exposure method having a short exposure time is sufficient. A resolution resist pattern can be formed. In addition, it is sufficiently effective in improving the resist peeling characteristics.

  Moreover, this invention is a manufacturing method of a printed wiring board which has the process of etching or plating the circuit formation board | substrate with which the resist pattern was formed by the said formation method of a resist pattern, and forming a conductive pattern. According to this printed wiring board manufacturing method, since the circuit forming substrate on which the resist pattern is formed by the resist pattern forming method is used, a high-density wiring can be formed, and disconnection and short circuit are sufficiently suppressed. Printed wiring boards can be manufactured.

  According to the present invention, it is possible to provide a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for producing a printed wiring board that are sufficiently effective in improving resolution and resist stripping characteristics.

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

  Hereinafter, preferred embodiments of the present 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.

  First, the binder polymer as component (A) will be described.

(A) In the general formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an OH group, or the like. Represents a halogen atom, and m represents an integer of 0 to 5; Examples of the polymerizable monomer that gives the structural unit represented by the general formula (I) include styrene and styrene derivatives. 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). Examples of the styrene derivative include α-methylstyrene.

Further, in the above general formula (II), ^{R 3} represents a hydrogen atom or a methyl group, ^{R 4} represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, OH group or a halogen atom, m shows the integer of 0-5. Examples of the polymerizable monomer that gives the structural unit represented by the general formula (II) include benzyl (meth) acrylate or benzyl (meth) acrylate. Examples of the benzyl (meth) acrylate derivative include 4-methylbenzyl (meth) acrylate.

In the general formula (III), R ⁵ represents a hydrogen atom or a methyl group. (Meth) acrylic acid is mentioned as a polymerizable monomer which gives the structural unit represented by general formula (III).

Further, in the general formula (IV), R ⁶ each independently represent a hydrogen atom or a methyl group, R ⁷ is 0-5 carbon atoms an alkyl group having 1 to 6 carbon atoms, m or n each independently Indicates an integer. From the viewpoint of shortening the peeling time and improving the resolution, R ⁷ is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 1 carbon atom (methyl group). (Meth) acrylic acid alkyl ester is mentioned as a polymerizable monomer which gives the structural unit represented by general formula (IV).

Examples of the (meth) acrylic acid alkyl ester include compounds represented by the following general formula (V).
^{_{CH 2 = C (R 8)}} -COOR 9 (V)

Here, in the general formula (V), R ⁸ represents a hydrogen atom or a methyl group, R ⁹ represents an alkyl group having 1 to 6 carbon atoms. The alkyl group having 1 to 6 carbon atoms represented by R ^9, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and structural isomers thereof. Examples of the polymerizable monomer represented by the general formula (V) include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, and (meth) acrylic acid butyl. Examples include esters, (meth) acrylic acid pentyl esters, and (meth) acrylic acid hexyl esters. These polymerizable monomers are used alone or in combination of two or more.

  In the binder polymer as the component (A), the content of the structural unit represented by the general formula (I) is preferably 10 to 60 parts by mass with respect to 100 parts by mass of the total amount of the component (A). The amount is more preferably 15 to 55 parts by mass, further preferably 20 to 50 parts by mass, and particularly preferably 20 to 40 parts by mass. Thereby, both the adhesiveness with respect to the circuit formation board | substrate of a photosensitive resin composition layer containing the photosensitive resin composition, and a resist peeling characteristic can be made favorable.

  Moreover, it is preferable that the content rate of the structural unit represented by the said general formula (II) is 10-60 mass parts with respect to 100 mass parts of total amounts of (A) component, and is 15-55 mass parts. More preferably, it is 20-50 mass parts, More preferably, it is 25-45 mass parts. Thereby, both the adhesiveness with respect to the circuit formation board | substrate of a photosensitive resin composition layer containing the photosensitive resin composition, and a resist peeling characteristic can be made favorable.

  Moreover, it is preferable that the content rate of the structural unit represented by the said general formula (III) is 10-60 mass parts with respect to 100 mass parts of total amounts of (A) component, and is 15-50 mass parts. It is more preferable that it is 20-40 mass parts, and it is especially preferable that it is 25-35 mass parts. Thereby, both resist stripping characteristics and developability can be improved.

  Moreover, it is preferable that the content rate of the structural unit represented by the said general formula (IV) is 1 to less than 15 mass parts with respect to 100 mass parts of total amounts of (A) component, and 2 to 13 masses Is more preferably 4 to 12 parts by mass, and particularly preferably 5 to 10 parts by mass. Thereby, both the adhesiveness with respect to the circuit formation board | substrate of a photosensitive resin composition layer containing the photosensitive resin composition, and a resist peeling characteristic can be made favorable.

  Further, in the binder polymer as the component (A), when the content ratio of the structural unit represented by the general formula (I) and the structural unit represented by the general formula (II) is less than 10 parts by mass, resolution is achieved. Tend to be inferior, and when the amount exceeds 60 parts by mass, the peeling piece tends to be large and the peeling time tends to be long. In addition, when the content ratio of the structural unit represented by the general formula (III) is less than 10 parts by mass, the alkali solubility is inferior, the peeling piece tends to be large, and the peeling time tends to be long. If it exceeds, the resolution tends to decrease. Moreover, if the content ratio of the structural unit represented by the general formula (IV) is less than 1 part by mass, the peelability tends to decrease, and if it is 15 parts by mass or more, the resolution tends to decrease.

  When preparing a photosensitive resin composition 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.

  (A) The weight average molecular weight (Mw) and number average molecular weight (Mn) of a 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 5,000 to 150,000, more preferably 10,000 to 100,000, and particularly preferably 20,000 to 50,000. When Mw is less than 5000, the developer resistance tends to decrease, and when it exceeds 150,000, the development time tends to be long.

  Moreover, (A) The dispersion degree (Mw / Mn) of the binder polymer is preferably 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.

  In addition, for example, a styrene resin, an epoxy resin, an amide resin, an amide epoxy resin, an alkyd resin, and a phenol resin can be used in combination with the (A) binder polymer. Moreover, these resin is used individually or in combination of 2 or more types.

  The binder polymer of the present invention can be produced, for example, by radical polymerization of a polymerizable monomer by a conventional method.

  The above (A) binder polymer may contain structural units other than the structural units represented by the above general formulas (I) to (IV). The above-mentioned (A) binder polymer most preferably has only the structural units represented by the above general formulas (I) to (IV), but to the extent that the object of the present invention is not impaired, You may have a structural unit about 1-10 mass parts with respect to the total amount of (A) component. In this case, examples of the polymerizable monomer that gives structural units other than the structural units represented by the general formulas (I) to (IV) include (meth) acrylic acid heptyl ester and (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, 2-hydroxyethyl, 2 -Acrylamides such as hydroxypropyl, 3-hydroxypropyl, 4-hydroxybutyl, diacetone acrylamide, esters of vinyl alcohol such as acrylonitrile, vinyl-n-butyl ether, (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic Dimethylamino acid Tilester, (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, malein Examples thereof include maleic acid monoesters such as monomethyl acid, monoethyl maleate and monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid and propiolic acid. These monomers are used alone or in 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) binder polymer is produced, for example, by radical polymerization of a polymerizable monomer having (meth) acrylic acid or other carboxyl group and another polymerizable monomer by a conventional method. be able to.

  (A) The acid value of the binder polymer is preferably 80 to 250 mgKOH / g, more preferably 100 to 220 mgKOH / g, and particularly preferably 150 to 210 mgKOH / g. When the acid value is less than 80 mgKOH / g, the development time tends to be long, and when it exceeds 250 mgKOH / 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.

  (B) As a compounding quantity of the binder polymer of (A) component, it is preferable that it is 30-70 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, and it is 35-65 mass parts. Is more preferable, and 40 to 60 parts by mass is particularly preferable. If this amount 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. (A) The binder polymer which is a component is used individually by 1 type or in combination of 2 or more types.

  Next, the photopolymerizable compound as the component (B) will be described.

  Examples of the photopolymerizable compound as component (B) include compounds obtained by reacting an α, β-unsaturated carboxylic acid with polyhydric alcohol, bisphenol A di (meth) acrylate compounds, and glycidyl group-containing compounds. Compounds obtained by reacting α, β-unsaturated carboxylic acids, urethane monomers such as (meth) acrylate compounds having a urethane bond in the molecule, nonylphenoxypolyethyleneoxyacrylate (also referred to as “nonylphenoxypolyethyleneglycol acrylate”), Examples thereof include phthalic acid compounds and (meth) acrylic acid alkyl esters. These compounds are 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, 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, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate , EO, PO modified trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipenta Examples include erythritol hexa (meth) acrylate. These compounds are 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 di (meth) acrylate compound include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxy). Polypropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane Etc. 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) acryloxy nanoe) 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 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) or FA-321M (trade name, manufactured by Hitachi Chemical Co., Ltd.). 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 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane is preferably 4 to 20, and more preferably 8 to 15. These compounds are used alone or in combination of two or more.

  As the (meth) acrylate compound having a urethane bond in the molecule, 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.) addition reaction product, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO modified urethane di (meth) acrylate, EO, PO modified urethane di (meth) acrylate, etc. Is mentioned. 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, PO-modified urethane di (meth) acrylate include UA-13 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). These compounds are used alone or in combination of two or more.

  Nonylphenoxypolyethyleneoxyacrylate includes, for example, nonylphenoxytetraethyleneoxyacrylate, nonylphenoxypentaethyleneoxyacrylate, nonylphenoxyhexaethyleneoxyacrylate, nonylphenoxyheptaethyleneoxyacrylate, nonylphenoxyoctaethyleneoxyacrylate, nonylphenoxynonaethyleneoxy Examples include acrylate, nonylphenoxydecaethyleneoxyacrylate, and nonylphenoxyundecaethyleneoxyacrylate. Examples of nonylphenoxyoctaethyleneoxyacrylate include M-114 (trade name, manufactured by Toagosei Co., Ltd.). These compounds are used alone or in 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. are mentioned. These compounds are used alone or in combination of two or more.

  Furthermore, 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. preferable. 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 is further 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 may be continuously present in blocks or 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.

で表される化合物、下記一般式（ＶＩＩ）：

で表される化合物、及び下記一般式（ＶＩＩＩ）：

で表される化合物などが挙げられる。ここで、式（ＶＩ）、式（ＶＩＩ）及び式（ＶＩＩＩ）中、Ｒ^１０，Ｒ^１１，Ｒ^１２，Ｒ^１３，Ｒ^１４，及びＲ^１５はそれぞれ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^４及びｎ^１〜ｎ^４はそれぞれ独立に１〜３０の整数を示す。これらの化合物は単独で又は２種類以上を組み合わせて用いられる。 Among these (B) components, polyalkylene glycol di (meth) acrylate having at least one polymerizable ethylenically unsaturated bond and having both an ethylene glycol chain and a propylene glycol chain in the molecule is, for example, Formula (VI):

A compound represented by the following general formula (VII):

And a compound represented by the following general formula (VIII):

The compound etc. which are represented by these are mentioned. Here, in formula (VI), formula (VII), and formula (VIII), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ are each independently a hydrogen atom or a group having 1 to 3 carbon atoms. Represents an alkyl group, EO represents an ethylene glycol chain, PO represents a propylene glycol chain, and m ^{1 to} m ⁴ and n ^{1 to} n ⁴ each independently represents an integer of 1 to 30; These compounds are used alone or in combination of two or more.

  Examples of the alkyl group having 1 to 3 carbon atoms in the general formulas (VI) to (VIII) include a methyl group, an ethyl group, an n-propyl group, and an i-propyl group.

In addition, the total number (m ¹ + m ² , m ³ and m ⁴ ) of ethylene glycol chain repeats in the general formulas (VI) to (VIII) is an integer of 1 to 30, and an integer of 1 to 10 Is preferable, an integer of 4 to 9 is more preferable, and an integer of 5 to 8 is particularly preferable. If the number of repetitions exceeds 30, the tent reliability and the resist shape tend to deteriorate.

In addition, the total number of propylene glycol chain repeats (n ¹ , n ² + n ³ and n ⁴ ) in the general formulas (VI) to (VIII) is an integer of 1 to 30, and an integer of 5 to 20 Is preferable, an integer of 8 to 16 is more preferable, and an integer of 10 to 14 is particularly preferable. 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 (VI) include, for example, vinyl having R ¹⁰ = R ¹¹ = methyl group, m ¹ + m ² = 4 (average value), and n ¹ = 12 (average value). And compounds (trade name: FA-023M, manufactured by Hitachi Chemical Co., Ltd.). Specific examples of the compound represented by the general formula (VII) include, for example, R ¹² = R ¹³ = methyl group, m ³ = 6 (average value), n ² + n ³ = 12 (average value) A certain vinyl compound (manufactured by Hitachi Chemical Co., Ltd., trade name: FA-024M) is exemplified. Further, specific examples of the compound represented by the general formula (VIII) include, for example, vinyl in which R ¹⁴ = R ¹⁵ = hydrogen atom, m ⁴ = 1 (average value), and n ⁴ = 9 (average value). Examples thereof include compounds (manufactured by Shin-Nakamura Chemical Co., Ltd., sample name: NK ester HEMA-9P). These compounds are used alone or in combination of two or more.

  (B) As a compounding quantity of the photopolymerizable compound of a component, it is preferable that it is 30-70 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, and is 35-65 mass parts. It is more preferable, and it is especially preferable that it is 40-60 mass parts. If the amount 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.

  (B) The photopolymerizable compound which is a component is used individually by 1 type or in combination of 2 or more types. This photopolymerizable compound preferably contains a bisphenol A (meth) acrylate compound or a (meth) acrylate compound having a urethane bond in the molecule from the viewpoint of improving plating resistance and adhesion. Moreover, it is preferable that a bisphenol A type (meth) acrylate compound is included from a viewpoint of improving a sensitivity and a resolution.

  The photopolymerizable compound (B) is a photopolymerization having one polymerizable ethylenically unsaturated bond in the molecule from the viewpoint of reducing the size of the resist strip and shortening the stripping time. The photopolymerizable unsaturated compound having one polymerizable ethylenically unsaturated bond in the molecule and two or more polymerizable ethylenically unsaturated bonds in the molecule are preferable. It is more preferable to use in combination with a photopolymerizable unsaturated compound. In this case, for example, as the photopolymerizable unsaturated compound having one polymerizable ethylenically unsaturated bond in the molecule, phenoxypolyethyleneoxy (meth) acrylate, phenoxypolyethyleneoxy-polypropyleneoxy (meth) acrylate, octylphenoxy Hexaethyleneoxy (meth) acrylate, octylphenoxyheptaethyleneoxy (meth) acrylate, octylphenoxyoctaethyleneoxy (meth) acrylate, octylphenoxynonaethyleneoxy (meth) acrylate, octylphenoxydecaethyleneoxy (meth) acrylate, nonylphenoxy Polyethyleneoxy (meth) acrylate, nonylphenoxypolyethyleneoxy-polypropyleneoxy (meth) acrylate, (meth) acrylic Phthalic acid derivative having a group. Examples of the photopolymerizable unsaturated compound having two or more polymerizable ethylenically unsaturated bonds in the molecule include 1,6-hexanediol di (meth) acrylate and 1,4-cyclohexanediol di (meth). Acrylate, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups, polypropylene glycol di (meth) acrylate having 2 to 14 propylene groups, polyethylene of the above general formulas (VI) to (VIII) -Polypropylene glycol di (meth) acrylate, bisphenol A di (meth) acrylate, di (meth) acrylate having a urethane bond in the molecule, bis (acryloxyethyl) hydroxyethyl isocyanurate, bisphenol A diglycidyl ether di (meth) ) Acrylate, lid (Meth) acrylic acid adduct of glycidyl ester and the like.

  In addition, from the viewpoint of improving the resolution, stripping time and exposure tolerance in a balanced manner, one kind of photopolymerizable unsaturated compound having one polymerizable ethylenically unsaturated bond in the molecule and two or more in the molecule. It is particularly preferred to use a combination of two types of photopolymerizable unsaturated compounds having a polymerizable ethylenically unsaturated bond. In this case, examples of the photopolymerizable unsaturated compound having one polymerizable ethylenically unsaturated bond in the molecule include phenoxypolyethyleneoxy (meth) acrylate, nonylphenoxypolyethyleneoxy (meth) acrylate, and (meth) acrylic. Any one of phthalic acid derivatives having a group can be used. Examples of the photopolymerizable unsaturated compound having two or more polymerizable ethylenically unsaturated bonds in the molecule include polyethylene / polypropylene glycol di (meth) acrylates of the above general formulas (VI) to (VIII). , EO-modified urethane di (meth) acrylate and EO, PO-modified urethane di (meth) acrylate, and a bisphenol A di (meth) acrylate compound may be used in combination.

  Next, the photopolymerization initiator which is the component (C) will be described.

  Examples of the photopolymerization initiator (C) include 4,4′-bis (diethylamino) benzophenone, benzophenone, and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2. -Aromatic ketones such as methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, quinones such as alkylanthraquinones, benzoin ether compounds such as benzoin alkyl ether, benzoins such as benzoin and alkylbenzoin 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-diph 2,4,5 such as nilimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer -Acridine derivatives such as -triarylimidazole dimer, 9-phenylacridine, 1,7-bis (9,9'-acridinyl) heptane.

  In the 2,4,5-triarylimidazole dimer, the substituents of the aryl groups of the two 2,4,5-triarylimidazoles may be the same and may give the target compound. Asymmetric compounds may be provided. The photopolymerization initiator is preferably a hexaarylbiimidazole compound that is a 2,4,5-triarylimidazole dimer from the viewpoint of adhesion and sensitivity. These photopolymerization initiators are used alone or in combination of two or more.

  In addition, the blending amount of the photopolymerization initiator that is the component (C) is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B), and 2 to 6 It is more preferable that it is a mass part, and it is especially preferable that it is 3.5-5 mass parts. If the amount is less than 0.1 parts by mass, good sensitivity and resolution tend to be difficult to obtain, and if it exceeds 10 parts by mass, there is a tendency that a resist pattern having a desired shape cannot be obtained. (C) The photoinitiator which is a component is used individually by 1 type or in combination of 2 or more types.

  The photosensitive resin composition of the present invention preferably contains (D) a sensitizing dye and / or (E) an amine compound in addition to the components (A) to (C) described above.

  The sensitizing dye which is the component (D) in the present invention can effectively use the absorption wavelength of actinic rays used for exposure, and is preferably a compound having a maximum absorption wavelength of 370 to 420 nm. 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. When the maximum absorption wavelength of the sensitizing dye is less than 370 nm, the sensitivity to direct drawing exposure light tends to decrease, and when it exceeds 420 nm, the stability tends to decrease even in a yellow light environment.

  Examples of sensitizing dyes include pyrazolines, anthracenes, coumarins, xanthones, oxazoles, benzoxazoles, thiazoles, benzothiazoles, triazoles, stilbenes, triazines, thiophenes, naphthalimides, etc. Is mentioned. The sensitizing dye preferably contains anthracene from the viewpoint of improving the resolution, adhesion and sensitivity. Moreover, it is preferable that it is 0.01-10 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, and, as for the compounding quantity of a sensitizing dye, it is 0.05-5 mass parts. Is more preferable, and 0.1 to 2 parts by mass is particularly preferable. If the blending 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 resist pattern having a good shape as desired tends not to be obtained. (D) The sensitizing dye which is a component is used individually by 1 type or in combination of 2 or more types.

  The amine compound as the component (E) is not particularly limited as long as it has an amino group in the molecule and can increase the sensitivity of the photosensitive resin composition. Specific examples thereof include bis [4- (dimethylamino) phenyl] methane, bis [4- (diethylamino) phenyl] methane, and leuco crystal violet. The compounding amount of the amine compound is preferably 0.01 to 10 parts by mass and more preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B). The content is preferably 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, the component (E) tends to precipitate as foreign matter after film formation. The amine compound which is (E) component is used individually by 1 type or in combination of 2 or more types.

  In the photosensitive resin composition of the present invention, 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, or the like is included as necessary. Dye, photochromic agent such as tribromophenylsulfone, leucocrystal violet, thermochromic inhibitor, plasticizer such as p-toluenesulfonamide, pigment, filler, antifoaming agent, flame retardant, stabilizer, adhesion promoter , A leveling agent, a peeling accelerator, an antioxidant, a fragrance, an imaging agent, a thermal cross-linking agent, etc. be able to. These may be 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 to using the coating solution to form the photosensitive resin composition layer of the photosensitive element, for example, the coating solution is applied as a liquid resist on the surface of a metal plate, dried, and then coated with a protective film. It may be used. Examples of the material for the metal plate include copper, copper-based alloys, iron-based alloys such as nickel, chromium, iron, and stainless steel, preferably copper, copper-based alloys, and iron-based alloys.

  Next, the photosensitive element of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the photosensitive element of the present invention. A photosensitive element 1 shown in FIG. 1 includes a support film 2, a photosensitive resin composition layer 3 containing the photosensitive resin composition formed on the support film 2, and a photosensitive resin composition layer 3. It is comprised with the protective film 4 laminated | stacked on.

  As the support film 2, 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, for example, polypropylene films such as Alfane MA-410, E-200C (above, trade name) manufactured by Oji Paper Co., Ltd., Shin-Etsu Film Co., Ltd., and PS series manufactured by Teijin Limited (for example, Examples include, but are not limited to, polyethylene terephthalate films such as trade name: PS-25).

  Moreover, it is preferable that the support film 2 is 1-100 micrometers in thickness, and it is more preferable that it is 5-25 micrometers. If the thickness is less than 1 μm, the support film tends to be broken when the support film is peeled off before development, and if it exceeds 100 μm, the resolution tends to decrease. The support film 2 is used by laminating one side as a support for the photosensitive resin composition layer and the other as a protective film for the photosensitive resin composition layer on both sides of the photosensitive resin composition layer. Also good.

  The photosensitive resin composition layer 3 is prepared by dissolving the photosensitive resin composition 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 this solution onto the support film 2. It is preferable to form it by applying to and drying. The coating can be performed by a known method using, for example, a roll coater, comma coater, gravure coater, air knife coater, die coater, bar coater or the like. 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 3 changes with uses of the photosensitive element, it is preferable that it is 1-100 micrometers in 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 be reduced.

  Moreover, the photosensitive resin composition layer 3 preferably has a transmittance of 5 to 75% for light having a wavelength of 405 nm, more preferably 7 to 60%, and particularly preferably 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. Examples of the UV spectrometer include a 228A type W beam spectrophotometer (trade name) manufactured by Hitachi, Ltd.

  The protective film 4 preferably has a smaller adhesive force between the photosensitive resin composition layer 3 and the protective film 4 than the adhesive force between the photosensitive resin composition layer 3 and the support film 2, and has a low fish. Eye films are preferred. “Fish eye” means that when a material is heated and melted, kneaded, extruded, biaxially stretched, casting method, etc., foreign materials, undissolved materials, oxidized degradation products, etc. It is taken in.

  As the protective film 4, 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, for example, polypropylene films such as Alfane MA-410, E-200C (above, trade name) manufactured by Oji Paper Co., Ltd., Shin-Etsu Film Co., Ltd., and PS series manufactured by Teijin Limited (for example, Examples thereof include polyethylene terephthalate films such as trade name: PS-25), but are not limited thereto.

  The protective film 4 preferably has a thickness of 1 to 100 μm, more preferably 5 to 50 μm, further preferably 5 to 30 μm, and particularly preferably 15 to 30 μm. When the thickness is less than 1 μm, the protective film tends to be broken during lamination, and when it exceeds 100 μm, the cost tends to be inferior.

  In addition, the photosensitive element 1 of the present invention may further include 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 1 can be wound up and stored in a sheet form or a roll around a core. In addition, it is preferable to wind up so that the support film 1 may become the outermost side in this case. 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).

  Next, the resist pattern forming method of the present invention will be described.

  The method for forming a resist pattern according to the present invention comprises a lamination step of laminating the photosensitive resin composition layer containing the photosensitive resin composition on a circuit forming substrate, and an active portion of the photosensitive resin composition layer. It includes at least an exposure step of irradiating light to photocure the exposed portion and a developing step of removing the photosensitive resin composition in a portion other than the exposed portion from the circuit forming substrate. The “circuit forming substrate” refers to a substrate including an insulating layer and a conductor layer formed on the insulating layer. Further, the circuit forming substrate may be multilayered and may have wiring formed therein, and may have a small-diameter through hole.

The following method is mentioned as a lamination | stacking method of the photosensitive resin composition layer on the circuit formation board | substrate in a lamination process. First, the protective film is gradually peeled from the photosensitive resin composition layer, and at the same time, the portion of the surface of the photosensitive resin composition layer that is gradually exposed is brought into close contact with the surface of the circuit forming substrate on which the circuit is formed. . And it laminates | stacks by crimping | bonding the photosensitive resin composition layer to the circuit formation board | substrate, heating the photosensitive resin composition layer. In addition, it is preferable to laminate | stack this operation | work under reduced pressure from the standpoint of adhesiveness and follow-up improvement. 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, the circuit forming substrate is not necessary. It is also possible to perform a pre-heat treatment.

  Examples of the method for forming the exposed portion in the exposure 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 transmits actinic rays, the support film can be irradiated with actinic rays, and when the support film is light-shielding, the support film After removing the light, the photosensitive resin composition layer is irradiated with actinic rays. Alternatively, a method of irradiating actinic rays in an image form by a direct drawing exposure method such as a laser direct drawing exposure method or a DLP (Digital Light Processing) exposure method may be employed.

  Examples of the active light source include 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, and visible light. That effectively radiate are used.

  As a method for removing portions other than the exposed portion in the development step, first, when a support film is present on the photosensitive resin composition layer, the support film is removed, and then wet development, dry development, etc. And a method of developing by removing portions other than the exposed portion. Thereby, a resist pattern is formed.

  For example, in the case of wet development, a developer corresponding to a photosensitive resin composition such as an alkaline aqueous solution, an aqueous developer, or an organic solvent developer is used, for example, a dip method, a battle method, a spray method, or a rocking immersion. Development is performed by a known method such as brushing or scraping. As the phenomenon method, the high pressure spray method is most suitable for improving the resolution. Moreover, you may use together 2 or more types of image development methods as needed.

  As the developer, an alkaline aqueous solution which is safe and stable and has good operability 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, alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate, borax and the like are used.

  The alkaline aqueous solution used for development includes a dilute solution of 0.1 to 5% by mass sodium carbonate, a dilute solution of 0.1 to 5% by mass potassium carbonate, and a dilute solution of 0.1 to 5% by mass sodium hydroxide. A dilute solution of 0.1 to 5% by mass sodium tetraborate (borax) is preferable. Moreover, it is preferable to make pH of this alkaline aqueous solution into the range of 9-11, and the temperature is adjusted according to the 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 accelerating development may be added.

  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, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1, 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, and 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 may be 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. In addition, a small amount of a surfactant, an antifoaming agent, or the like can be added to the aqueous developer.

  Examples of the organic solvent developer using an organic solvent alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. It is done. These organic solvent-based developers are preferably added with water in an amount of 1 to 20% by mass in order to prevent ignition.

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.

  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 is a method of forming a conductor pattern by 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 are performed on the conductor layer of the circuit forming substrate and the like 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. And 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, for example, a stronger alkaline aqueous solution than the alkaline aqueous solution used for development. 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 an immersion method and a spray method, and the immersion method and the spray method may be used alone or in combination. A printed wiring board is obtained as described above.

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

  EXAMPLES Hereinafter, although the preferable Example of this invention is described in detail, this invention is not limited to these Examples.

(Synthesis of binder polymer (component (A))
To a flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas introduction tube, 450 g of a mixture of methyl cellosolve and toluene at a mass ratio of 3: 2 was added, and the mixture was stirred while blowing nitrogen gas. Heated to ° C. On the other hand, a solution (hereinafter referred to as “solution a”) in which 150 g of methacrylic acid, 25 g of methyl methacrylate, 125 g of benzyl methacrylate, and 200 g of styrene and 9.0 g of azobisisobutyronitrile were mixed as a comonomer. The solution a was added dropwise to a prepared mixture of methyl cellosolve and toluene having a mass ratio of 3: 2 prepared in advance over 4 hours, and then kept warm at 80 ° C. for 2 hours with stirring. Furthermore, a solution in which 1.2 g of azobisisobutyronitrile was dissolved in 100 g of a mixture of methyl cellosolve and toluene having a mass ratio of 3: 2 was dropped over 10 minutes. The solution after dropping was kept at 80 ° C. for 3 hours with stirring, and then heated to 90 ° C. over 30 minutes. The mixture was kept at 90 ° C. for 2 hours and then cooled 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 30,000. 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.
Pump: Hitachi L-6000 type (trade name, 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., trade name)

Further, binder polymers (A-2) to (A-10) were synthesized by the same method as the synthesis method of the binder polymer (A-1) described above so as to have the composition shown in Table 1 below.

(Preparation of photosensitive resin composition)
The binder polymers (A-1) to (A-10) and the following materials are blended in the mass ratio shown in Table 2, and the photosensitive resin compositions of Examples 1 to 6 and Comparative Examples 1 to 5 are used. A solution was prepared.
<Photopolymerizable compound (component (B))>
B-1: 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane (manufactured by Hitachi Chemical Co., Ltd., trade name: FA-321M)
B-2: A compound represented by the above general formula (VII), wherein R ¹² and R ¹³ are each a methyl group, m ³ = 6 (average value), and n ² + n ³ = 12 (average value). Vinyl compound (manufactured by Hitachi Chemical Co., Ltd., trade name: FA-024M)
B-3: 4-Normal nonylphenoxyoctaethyleneoxyacrylate (manufactured by Toagosei Co., Ltd., trade name: M-114)
<Photopolymerization initiator (component (C))>
C-1: 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbisimidazole (manufactured by Hampford, trade name: BCIM)
<Sensitizing dye (component (D))>
D-1: 9,10-dibutoxyanthracene (manufactured by Kawasaki Kasei Kogyo Co., Ltd., trade name: DBA, wavelengths [λn] = 368 nm, 388 nm, 410 nm indicating absorption maximum)
<(E) Color former (amine compound)>
E-1: Leuco Crystal Violet (manufactured by Yamada Chemical Co., Ltd.)
<Dye>
Malachite green (Osaka Organic Chemical Industry Co., Ltd.)
<Solvent>
Acetone toluene methanol

(Production of photosensitive element)
The solution of each obtained photosensitive resin composition was uniformly apply | coated on the 16-micrometer-thick polyethylene terephthalate film used as a support film. Then, it dried using a 70 degreeC and 110 degreeC hot air convection dryer, and formed the photosensitive resin composition layer whose film thickness after drying is 25 micrometers. Then, the protective film was laminated | stacked on the photosensitive resin composition layer by roll pressurization, and the photosensitive element which concerns on each Examples 1-6 and Comparative Examples 1-5 was obtained.

(Preparation of test piece)
Subsequently, the copper surface of a copper-clad laminate (manufactured by Hitachi Chemical Co., Ltd., trade name: MCL-E-67), which is a glass epoxy material in which copper foil (thickness 35 mm) is laminated on both sides, is equivalent to # 600. Polishing was performed using a polishing machine having a brush (manufactured by Sankei Co., Ltd.), washed with water, and then dried with an air flow to obtain a copper clad laminate (substrate). Then, after heating the copper-clad laminate to 80 ° C., each photosensitive resin composition layer is placed on the surface of the copper-clad laminate while removing the protective film of each photosensitive element on the copper-clad laminate. Lamination was performed at 120 ° C. under a pressure of 4 kgf / cm ² so as to adhere to each other, and a test piece was produced.

(Characteristic evaluation)
<Light sensitivity>
When the copper clad laminate on which each photosensitive element is laminated is cooled to 23 ° C., the support film has a density region of 0.00 to 2.00, a density step of 0.05, and a tablet size of 20 mm × 187 mm. A photo tool having a 41-step tablet having a size of 3 mm × 12 mm for each step was brought into close contact. Using a direct drawing machine DE-1AH (trade name) manufactured by Hitachi Via Mechanics Co., Ltd., which uses a 405 nm blue-violet laser diode as a light source, it is photosensitive via a photo tool and a support film at an exposure amount of 50 mJ / cm ² . The resin composition layer was exposed (drawn). The illuminance was measured using an ultraviolet illuminance meter (USHIO Corporation, trade name: UIT-150) to which a 405 nm probe was applied.

  Subsequently, the support film was peeled off, and a 1% by mass aqueous sodium carbonate solution was sprayed at 30 ° C. for 24 seconds to remove an unexposed portion of the photosensitive resin composition layer and develop it. 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 evaluation of 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. Table 4 shows the obtained results.

<Resolution>
The resolution was exposed using a phototool having a wiring pattern of line width / space width 6/6 to 30/30 (unit: mm) as a negative for resolution evaluation. Here, in the resist pattern formed by development after exposure, the resolution is the smallest value (unit: μm) of the space width between the line widths in the portion where the unexposed portion is removed cleanly. . The smaller the numerical value, the better the resolution evaluation. Table 4 shows the obtained results.

<Resist shape>
The resist shape after development was observed using a scanning electron microscope (trade name: Hitachi scanning electron microscope S-500A). The resist shape is preferably close to a rectangle.

<Peelability>
The peelability was evaluated by the following method. First, a photosensitive resin composition layer according to each example and comparative example is formed on a copper-clad laminate, and each photosensitive resin composition layer is exposed to a phenomenon to be a photocured film having a size of 40 mm × 50 mm. Was made. Then, peeling was performed using a 3% aqueous sodium hydroxide solution. In the evaluation of peelability, the time required for the photocured film to finish peeling from the copper clad laminate was defined as the peel time. Moreover, the size of the peeling piece after peeling completion was observed visually. Table 3 shows the condition of the peeling process and the index of the size of the peeling piece. Table 4 shows the obtained results.

<Evaluation results>
As shown in Table 4, each of Examples 1 to 6 had a high resolution of 10 μm, a moderately short peeling time, and a small peeling piece size, which balanced the resolution and peelability. . On the other hand, in Comparative Examples 1, 2, and 5, although the peelability was good, the resolution was low. In Comparative Examples 3 and 4, although the resolution was high, the peeling time was long and the peeling piece size was large. As described above, the effect of the photosensitive resin composition according to the present invention was confirmed.

  According to the present invention, it is possible to provide a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for producing a printed wiring board that are sufficiently effective in improving resolution and resist stripping characteristics.

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

Claims (10)

(A) a divalent group represented by the following general formula (I), a divalent group represented by the following general formula (II), a divalent group represented by the following general formula (III), A binder polymer having a divalent group represented by the following general formula (IV) and a dispersity of 1.0 to 2.0:
(B) a photopolymerizable compound, and (C) a photopolymerization initiator,
Containing
The (A) binder polymer is a photosensitive resin composition further comprising at least one of a structural unit based on (meth) acrylic acid 2-ethylhexyl ester and a structural unit based on (meth) acrylic acid dodecyl ester.

[Formula (I), Formula (II), formula (III), and formula ^{(IV), R 1, R} 3, R 5, and ^{R 6} independently represent a hydrogen atom or a methyl group, ^{R 2} and R ⁴ independently represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an OH group, or a halogen atom, R ⁷ represents an alkyl group having 1 to 6 carbon atoms, m or n Each independently represents an integer of 0 to 5, and when m or n is 2 to 5, a plurality of R ² or R ⁴ may be the same or different from each other. ]   The (A) binder polymer is 10 to 60 parts by mass of the divalent group represented by the general formula (I) with respect to 100 parts by mass in total, and the divalent group represented by the general formula (II). 10 to 60 parts by mass, 20 to 50 parts by mass of the divalent group represented by the general formula (III), and 1 to 15 parts by mass of the divalent group represented by the general formula (IV). The photosensitive resin composition of Claim 1 which has less than a mass part.   The photosensitive resin composition of Claim 1 or 2 whose weight average molecular weights of the said (A) binder polymer are 20000-50000.   The photosensitivity as described in any one of Claims 1-3 in which the said (B) photopolymerizable compound contains the polyalkylene glycol di (meth) acrylate which has both an ethylene glycol chain and a propylene glycol chain in a molecule | numerator. Resin composition.   The photosensitive resin composition according to claim 1, wherein the (C) photopolymerization initiator has a hexaarylbiimidazole compound.   (D) The photosensitive resin composition as described in any one of Claims 1-5 which further contains a sensitizing dye.   (E) The photosensitive resin composition as described in any one of Claims 1-6 which further contains an amine compound.   A photosensitive element provided with a support film and the photosensitive resin composition layer containing the photosensitive resin composition as described in any one of Claims 1-7 formed on the said support film.   A lamination step of laminating a photosensitive resin composition layer containing the photosensitive resin composition according to any one of claims 1 to 7 on a circuit-forming substrate, a predetermined portion of the photosensitive resin composition layer An exposure step of irradiating actinic rays to photo-curing the exposed portion, and removing a portion other than the exposed portion of the photosensitive resin composition layer from the circuit forming substrate on which the photosensitive resin composition layer is laminated. A method for forming a resist pattern having a development step.   A method for producing a printed wiring board, comprising: forming a conductor pattern by 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 9.

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