JP2009042720A - Photosensitive resin composition, photosensitive element, resist pattern forming method and method for manufacturing printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for forming a resist pattern with sufficiently high sensitivity and resolution and ensuring sufficiently excellent peeling property of the formed resist pattern. <P>SOLUTION: The photosensitive resin composition comprises (A) a binder polymer having structural units of (1) (meth)acrylic acid, (2) a styrene derivative, and (3) a (meth)acrylic phenoxyalkyl ester derivative, (B) a photopolymerizable compound, and (C) a photopolymerization initiator. <P>COPYRIGHT: (C)2009,JPO&INPIT

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, resist stripping properties, and adhesion. If the photosensitive resin composition can provide a resist pattern with excellent resolution and adhesion, 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 stripping characteristics using a specific binder polymer, photopolymerization initiator, and the like has been proposed (for example, Patent Documents 1 and 2). reference).
JP 2006-234959 A JP 2005-122123 A

  However, the photosensitive resin compositions described in Patent Documents 1 and 2 fail to form a resist pattern that sufficiently satisfies all of sensitivity, resolution, and resist stripping characteristics.

  Therefore, the present invention has been made in view of the above circumstances, and can form a resist pattern with sufficiently high sensitivity and resolution, and has a photosensitive resin composition and photosensitivity that are sufficiently excellent in the peeling characteristics of the formed resist pattern. It is an object to provide an element, a method for forming a resist pattern using the element, and a method for manufacturing a printed wiring board.

In order to achieve the above object, the present invention provides (A) a binder polymer having a divalent group represented by the following general formulas (I), (II) and (III), (B) a photopolymerizable compound, And (C) a photosensitive resin composition containing a photopolymerization initiator.

Here, in formulas (I), (II) and (III), R ¹ , R ² and R ⁴ each independently represent a hydrogen atom or a methyl group, and R ³ and R ⁵ each independently represent a carbon number of 1 to An alkyl group having 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a hydroxyl group, a phenyl group, a phenoxy group, a benzyl group, a phenylalkyl group, a cycloalkyl group having 5 or more carbon atoms, or a halogen atom; m and n each independently represents an integer of 0 to 5, s represents an integer of 1 to 5, and when m or n is 2 to 5, a plurality of R ³ or R ⁵ may be the same or different from each other. Good.

  The photosensitive resin composition of the present invention is configured by combining the specific components as described above, and has the same excellent sensitivity in the formation of resist patterns by the direct drawing exposure method. In addition, a resist pattern having a good shape can be formed with sufficiently high resolution, and the peelability of the formed resist pattern can be improved. By using a binder polymer having a specific group such as the component (A), the present inventors have obtained a sufficient effect as compared with the conventional technique with respect to all of the sensitivity, resolution, and resist peeling characteristics as described above. Is thinking. Therefore, when the photosensitive resin composition of the present invention is used in forming a resist pattern or a printed wiring board, the process can be shortened and the product yield can be improved.

  In the present invention, (C) the photopolymerization initiator is preferably a hexaarylbiimidazole derivative. This improves the resolution and adhesion of the resist pattern and improves sludge removal.

  The photosensitive resin composition preferably further contains (D) a sensitizing dye. Thereby, when exposing with the light which has a peak in a specific wavelength range, maximum absorption can be given to the vicinity of the specific wavelength range, and the sensitivity of the photosensitive resin composition is further improved.

  Moreover, it is preferable that the photosensitive resin composition which concerns on this invention further contains (E) amine compound. Thereby, the sensitivity of the photosensitive resin composition can be further increased.

  The present invention provides a photosensitive element comprising a support film and a photosensitive resin composition layer containing the above-described photosensitive resin composition formed on the support film. According to this photosensitive element, 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, the sensitivity is sufficiently high and good. A resist pattern having a shape can be formed with sufficiently high resolution, and the peelability of the formed resist pattern can be improved.

  The present invention includes a step of laminating a photosensitive resin composition layer comprising the above photosensitive resin composition on a circuit forming substrate, and irradiating a predetermined portion of the photosensitive resin composition layer with actinic rays to illuminate an exposed portion. Provided is a resist pattern forming method having an exposure step of curing and a development 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. 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 patterning exposure method having a short exposure time is satisfactory. A resist pattern having a shape can be formed with sufficiently high resolution.

  The present invention also provides a printed wiring board manufacturing method including a step of etching or plating a circuit forming substrate on which a resist pattern has been formed by the resist pattern forming method to form a conductor pattern. According to this method for forming a printed wiring board, since a circuit forming substrate on which a resist pattern is formed by the above resist pattern forming method is used, high-density wiring can be formed, and disconnection and short circuit are sufficiently suppressed. Printed wiring boards can be manufactured.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to form a resist pattern with sufficiently high sensitivity and resolution, the photosensitive resin composition which is fully excellent in the peeling characteristic of the formed resist pattern can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. In the present specification, “(meth) acrylic acid” means “acrylic acid” and “methacrylic acid” corresponding thereto, and “(meth) acrylate” means “acrylate” and “methacrylate” corresponding thereto. means.

  The photosensitive resin composition of the present invention comprises (A) a binder polymer having a divalent group represented by the above general formulas (I), (II) and (III) (hereinafter also referred to as “structural unit”), It is a photosensitive resin composition containing (B) a photopolymerizable compound and (C) a photopolymerization initiator.

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

  The binder polymer as component (A) is a structural unit based on (meth) acrylic acid represented by the above general formula (I), a structural unit based on styrene or a derivative thereof represented by the above general formula (II), and It has a structural unit based on the (meth) acrylic acid phenoxyalkyl ester represented by the general formula (III) or a derivative thereof. Thereby, the sensitivity of the photosensitive resin composition can be made sufficiently excellent, and the resolution of the photosensitive resin composition layer using the photosensitive resin composition as a constituent material can be made sufficiently high, and a resist pattern having a good shape Can be formed. Then, the peelability of the formed resist pattern is sufficiently good.

Here, in the above formula (I), R ¹ represents a hydrogen atom or a methyl group, specifically a structural unit based on acrylic acid or methacrylic acid.

Further, in the above formula (II), ^{R 2} represents a hydrogen atom or a methyl group, ^{R 3} is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a hydroxyl group, a phenyl group, a phenoxy group, A benzyl group, a phenylalkyl group, a cycloalkyl group having 5 or more carbon atoms or a halogen atom is shown, and m is an integer of 0-5.

Furthermore, in the above formula (III), ^{R 4} represents a hydrogen atom or a methyl group, ^{R 5} is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a hydroxyl group, a phenyl group, a phenoxy group, A benzyl group, a phenylalkyl group, a cycloalkyl group having 5 or more carbon atoms, or a halogen atom is shown, n is an integer of 0 to 5, and s is an integer of 1 to 5.

  It is preferable that the content rate of the structural unit represented by the said general formula (I) in (A) component is 10-60 mass parts with respect to 100 mass parts of total amounts of (A) component, and 15-50 masses. Part is more preferable, 20-40 mass is still more preferable, and 25-35 mass part is especially preferable. Thereby, the developability of the resist pattern and the peeling property of the resist become more excellent. When the content ratio is less than 10 parts by mass, the peeling piece tends to be large or the peeling time tends to be long as the alkali solubility of the resist pattern is lowered. Moreover, when this content rate exceeds 60 mass parts, it exists in the tendency for the resolution to become inadequate. The structural unit represented by the general formula (I) is obtained from (meth) acrylic acid which is a polymerizable monomer.

  The content ratio of the structural unit represented by the general formula (II) in the component (A) is preferably 10 to 70 parts by mass with respect to 100 parts by mass of the total amount of the component (A), and 15 to 65 parts by mass. Part is more preferable, and 25 to 60 parts by mass is even more preferable. When the content is less than 10 parts by mass, the resolution tends to be insufficient, and when it exceeds 70 parts by mass, the peeled piece becomes large and the peeling time tends to be long. The structural unit represented by the general formula (II) is obtained from styrene which is a polymerizable monomer or a derivative thereof. Specific examples of the styrene derivative include methylstyrene, ethylstyrene, hydroxystyrene, butoxystyrene, chlorostyrene, bromostyrene, aminostyrene, and the like.

  It is preferable that the content rate of the structural unit represented by the said general formula (III) in (A) component is 5-60 mass parts with respect to 100 mass parts of total amounts of (A) component, 10-55 masses More preferably, it is 15 to 50 parts by mass. Thereby, the adhesiveness and the peeling property of the resist pattern are further improved. If this content is less than 5 parts by mass, the resolution tends to decrease. Moreover, when this content rate exceeds 60 mass parts, a peeling piece will become large and it exists in the tendency for peeling characteristics to fall.

  The structural unit represented by the general formula (III) is obtained from (meth) acrylic acid phenoxyalkyl ester or a derivative thereof which is a polymerizable monomer. Specific examples of the (meth) acrylic acid phenoxyethyl derivative include 2-phenoxyethyl (meth) acrylate, ethoxylated nonylphenyl (meth) acrylate, alkoxylated nonylphenyl (meth) acrylate, and alkoxylated 2-phenoxyethyl (meth). Examples include acrylate and EO cumylphenol (meth) acrylate. Such (meth) acrylic acid phenoxyalkyl ester derivatives can be obtained as commercial products. For example, 2-phenoxyethyl methacrylate is “SR340” (trade name, manufactured by Sartomer), 2-phenoxyethyl acrylate is “SR339A” (trade name, manufactured by Sartomer), and ethoxylated nonylphenyl acrylate is “SR504” (Sartomer). Product, trade name), alkoxylated nonylphenyl acrylate is available as “CD614” (trade name, manufactured by Sartomer), and alkoxylated 2-phenoxyethyl acrylate is available as “CD9087” (trade name, manufactured by Sartomer).

  In the present invention, the “styrene derivative” refers to a compound in which a hydrogen atom in a phenyl group of styrene is substituted with a substituent (an organic group such as an alkyl group, a hydroxyl group, or a halogen atom). In addition, “(meth) acrylic acid phenoxyalkyl ester derivative” means that a hydrogen atom in a phenoxy group of (meth) acrylic acid phenoxyalkyl ester is substituted with a substituent (an organic group such as an alkyl group, a hydroxyl group or a halogen atom). It means what was done.

  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.

  (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 measuring method, the Mw of the binder polymer is preferably 5,000 to 300,000, more preferably 10,000 to 150,000, and particularly preferably 30,000 to 80,000. 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.

  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.

  The binder polymer according to the present invention can be produced, for example, by radical polymerization of the above polymerizable monomer.

  The (A) binder polymer may contain structural units other than the structural units represented by the general formulas (I) to (III). In this case, examples of the polymerizable monomer that gives a structural unit other than the structural units represented by the general formulas (I) to (III) include acrylamide such as diacetone acrylamide, acrylonitrile, vinyl n-butyl ether, and the like. Esters of vinyl alcohol, alkyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate Esters, 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 , Β-styryl (meth) acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, monoesters of fumaric acid, cinnamic acid, α-cyanocinnamic acid, Itaconic acid, crotonic acid, propiolic acid can be mentioned. These can be used alone or in combination of two or more.

Examples of the (meth) acrylic acid alkyl ester include compounds represented by the following general formula (IV), compounds obtained by substituting alkyl groups of these compounds with hydroxyl groups, epoxy groups, halogen atoms, and the like. It is done.
^{_{CH 2 = C (R 6)}} -COOR 7 (IV)

Here, in said general formula (IV), R < ⁶ > shows a hydrogen atom or a methyl group, R < ⁷ > shows a C1-C12 alkyl group. Examples of the alkyl group having 1 to 12 carbon atoms represented by R ⁷ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, An undecyl group, a dodecyl group, and these structural isomers are mentioned. Examples of the polymerizable monomer represented by the general formula (IV) include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, and (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 Examples include esters, (meth) acrylic acid decyl esters, (meth) acrylic acid undecyl esters, and (meth) acrylic acid dodecyl esters. These polymerizable monomers can be used alone or in combination of two or more.

  The content ratio in the component (A) of structural units other than the structural units represented by the general formulas (I) to (III) is not particularly limited as long as the object of the present invention can be achieved. However, the content ratio is preferably 0 to 40 parts by mass, more preferably 0 to 20 parts by mass, and particularly preferably 0 to 10 parts by mass with respect to 100 parts by mass of the total amount of component (A). preferable.

  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) The acid value of the binder polymer is preferably 30 to 250 mgKOH / g, more preferably 80 to 220 mgKOH / g, and still more preferably 100 to 200 mgKOH / g. When the acid value is less than 30 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.

  As a compounding quantity of (A) component in the photosensitive resin composition of this invention, 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 35-65. It is more preferable that it is a mass part, and it is still more preferable that it is 40-60 mass parts. If the blending amount is less than 30 parts by mass, it is difficult to obtain a good shape of the resist pattern, and if it exceeds 70 parts by mass, it tends to be difficult to obtain good sensitivity and resolution. (A) A component can be used individually by 1 type or in combination of 2 or more types.

  Moreover, in the photosensitive resin composition of this invention, you may use together resin other than the said (A) component in the limit which can achieve the objective of this invention. Examples of such resins include acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, and phenol resins. Of these, acrylic resins are preferred from the standpoint of alkali developability. Moreover, these resin can be used individually by 1 type or in combination of 2 or more types.

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

  The photopolymerizable compound as the component (B) is, for example, a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol, a bisphenol A (meth) acrylate compound, a glycidyl group-containing compound with α, Compounds obtained by reacting β-unsaturated carboxylic acids, urethane monomers such as (meth) acrylate compounds having urethane bonds in the molecule, nonylphenoxypolyethyleneoxyacrylate, phthalic acid compounds, (meth) acrylic acid alkyl esters Can be mentioned. These compounds can be used alone or in combination of two or more.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include, 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. These compounds can 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) acryloxypoly). Propoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane, etc. Is mentioned. 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.

  The 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is “BPE-500” (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) or “FA-321M” (product manufactured by Hitachi Chemical Co., Ltd., product). The above-mentioned 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as “BPE-1300” (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). Are 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 compounds can be used alone or in 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 a hydroxyl 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 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 can 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 compounds can be 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. -Phthalates. As such phthalic acid compounds, for example, “FA-MECH” (trade name, manufactured by Hitachi Chemical Co., Ltd.) is commercially available. These compounds can be used alone or in 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. Further, from the viewpoint of shortening the peeling time, it is preferable to include a compound having one ethylenically unsaturated group in the molecule.

  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 do not need to be continuously present in blocks, but 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.

  Examples of the polyalkylene glycol di (meth) acrylate having both an ethylene glycol chain and a propylene glycol chain in the molecule in the component (B) include the following general formulas (V), (VI), and (VII). And the compounds represented.

Here, in formulas (V), (VI) and (VII), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently 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 m1 to m4 and n1 to n4 each independently represents an integer of 1 to 30. These compounds can 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 i-propyl group.

  In addition, the total number (m1 + m2, m3, and m4) of ethylene glycol chain repeats in the general formulas (V), (VI), and (VII) is an integer of 1-30, and an integer of 1-10. 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.

  The total number of propylene glycol chain repeats (n1, n2 + n3 and n4) in the general formulas (V), (VI) and (VII) is an integer of 1 to 30 and an integer of 5 to 20, respectively. 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 (V) include vinyl compounds (Hitachi Chemical Industry Co., Ltd.) where R ¹¹ = R ¹² = methyl group, m1 + m2 = 4 (average value), and n1 = 12 (average value). Product name "FA-023M"). Specific examples of the compound represented by the general formula (VI) include vinyl compounds (Hitachi Chemical Co., Ltd.) where R ¹³ = R ¹⁴ = methyl group, m3 = 6 (average value), and n2 + n3 = 12 (average value). A trade name “FA-024M” manufactured by Kogyo Co., Ltd.). Furthermore, specific examples of the compound represented by the general formula (VII) include a vinyl compound (Shin Nakamura) in which R ¹⁵ = R ¹⁶ = hydrogen atom, m4 = 1 (average value), and n4 = 9 (average value). Chemical Industry Co., Ltd., trade name "NK ester HEMA-9P"). These compounds can be used alone or in combination of two or more.

  The component (B) is composed of two kinds of compounds having two photopolymerizable bonds in one molecule and one kind having one photopolymerizable bond in one molecule among the above-mentioned photopolymerizable compounds. It is particularly preferred to use in combination with a compound. For example, when the component (B) is a (meth) acrylate compound, two types of (meth) acrylate compounds having two (meth) acryl groups in one molecule and one (meth) acryl group in one molecule It is particularly preferable to use a single (meth) acrylate compound in combination. Thereby, all of a photosensitivity, adhesiveness, resolution, and peelability can be improved with good balance.

  (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) A component can be used individually by 1 type or in combination of 2 or more types.

  Next, the photoinitiator which is (C) component is demonstrated.

  Examples of the photopolymerization initiator (C) include 4,4′-bis (diethylamino) benzophenone, benzophenone, 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-diphenylimi 2,4,5- such as sol dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer Examples include 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 derivative which 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 the sensitizing dye include pyrazolines, anthracenes, coumarins, xanthones, oxazoles, benzoxazoles, thiazoles, benzothiazoles, triazoles, stilbenes, triazines, thiophenes, and naphthalimides. Can be mentioned. The sensitizing dye preferably contains anthracene from the viewpoint of improving the resolution, adhesion and sensitivity.

  The blending amount of the sensitizing dye 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 components (A) and (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 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.

  If necessary, the photosensitive resin composition of the present invention includes a photopolymerizable compound (such as an oxetane compound) having at least one cationically polymerizable cyclic ether group in the molecule, a cationic polymerization initiator, malachite green, and the like. Dye, photochromic agent such as tribromophenylsulfone, leucocrystal violet, thermochromic inhibitor, plasticizer such as p-toluenesulfonamide, pigment, filler, antifoaming agent, flame retardant, stabilizer, adhesion promoter , Leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, and the like. These components 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 the component (A) and the component (B). These are used singly 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 of 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 polypropylene films such as “Alphan MA-410, E-200C” (trade name) manufactured by Oji Paper Co., Ltd., Shin-Etsu Film Co., Ltd., and PS series manufactured by Teijin Limited (for example, trade name “PS” -25 ") and the like, but not limited thereto.

  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 application can be performed by a known method using, for example, 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 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.

  The photosensitive resin composition layer 3 preferably has a transmittance for light having a wavelength of 365 nm or 405 nm of 5 to 75%, 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 with a UV spectrometer, and 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. Commercially available products include, for example, “Alphan MA-410, E-200C” (trade name) manufactured by Oji Paper Co., Ltd., polypropylene films manufactured by Shin-Etsu Film Co., Ltd., PS series manufactured by Teijin Limited (for example, trade name “PS” Polyethylene terephthalate film such as -25 "), but is not limited thereto.

  The protective film 4 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.

  Moreover, the photosensitive element 1 of this invention may have intermediate | middle layers, such as a cushion layer, an adhesive layer, a light absorption layer, and a gas barrier layer further. 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 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 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, an organic solvent developer, or the like 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 or the like that 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, and borax 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 weight sodium tetraborate (borax) is preferred. 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. 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, and diethylene glycol monobutyl ether. . 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. . 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 to form 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. Gold plating such as nickel plating, hard gold plating, and soft gold plating can be used.

  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.

  Thus, a printed wiring board is obtained. 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. By adopting the manufacturing method as described above, a printed wiring board such as a multilayer printed wiring board having a small diameter through hole can be suitably manufactured.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not restrict | limited to this.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

(Synthesis of binder polymer (component (A))
To a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen gas introduction tube, 450 g of a mixture of propylene glycol monomethyl ether and toluene with a mass ratio of 3: 2 was added and stirred while blowing nitrogen gas. And heated to 80 ° C. On the other hand, a solution (hereinafter referred to as “solution a”) prepared by mixing 150 g of methacrylic acid, 175 g of phenoxyethyl methacrylate and 175 g of styrene and 9.0 g of azobisisobutyronitrile as a comonomer was prepared. The solution a was added dropwise over a period of 4 hours to a blend of propylene glycol monomethyl ether and toluene having a mass ratio of 3: 2 prepared in advance, and then kept at 80 ° C. for 2 hours while stirring. Furthermore, a solution in which 1.2 g of azobisisobutyronitrile was dissolved in 100 g of a mixture of propylene glycol monomethyl ether and toluene having a mass ratio of 3: 2 was added dropwise 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 binder polymer (A-1) had a non-volatile content (solid content) of 47.8% by mass, an acid value of 196 mg / KOH / g, and a weight average molecular weight of 40000. 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 (made by Hitachi, trade name)
Column: Gelpack GL-R420 + Gelpack GL-R430 + Gelpack GL-R440 (three 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, trade name)

  Further, binder polymers (A-2) to (A-5) 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-5) and the following materials are blended in the mass ratio shown in Table 2, and the photosensitive resin compositions of Examples 1 to 3 and Comparative Examples 1 to 3 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 (VI), wherein R ¹³ = R ¹⁴ = methyl group, m3 = 6 (average value), n2 + n3 = 12 (average value) vinyl compound (Hitachi Chemical) Product name “FA-024M” manufactured by Kogyo Co., Ltd.)
B-3: 4-Normal nonylphenoxyoctaethylene glycol acrylate (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 (product name “BCIM” manufactured by Hampford)
<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 1-3 and Comparative Examples 1 and 2 was obtained.

(Preparation of test piece)
Subsequently, a 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 brushed with # 600 Polishing was performed using a polishing machine (manufactured by Sankeisha), 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. Photosensitive resin composition through a photo tool and a support film with a predetermined exposure amount using a direct drawing machine “DE-1AH” (trade name) manufactured by Hitachi Via Mechanics Co., Ltd. using a 405 nm blue-violet laser diode as a light source The layer was exposed (drawn). In addition, the number of remaining steps when a line width / space width of 6/6 to 22/22 (unit: mm) was used and 70 mJ / cm ² was exposed was shown as sensitivity. The illuminance was measured using an ultraviolet illuminometer (trade name: UIT-150, manufactured by Ushio Electric Co., Ltd.) 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 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.
Table 4 shows the obtained results.

<Resolution>
After development, the smallest dimension at which resolution adhesion was obtained was taken as the resolution. That is, the resolution (resolution adhesion) can remove the unexposed part cleanly by the development process after exposure, and the line is the smallest of the line width / space width formed without meandering and chipping. The value (unit: μm) was used as the evaluation index. The evaluation of the resolution is better as the numerical value is smaller. The results obtained are 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.

<Peeling characteristics>
The peelability of the resist pattern 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, each photosensitive resin composition layer is exposed and developed with a predetermined exposure amount, and has a size of 40 mm × 50 mm. A photocured film was prepared. Then, peeling was performed using a 3% aqueous sodium hydroxide solution. For the peelability, the time when the photocured film was completely peeled and removed from the copper clad laminate was measured as the peel time, and this was used as an evaluation index. Moreover, the size of the peeling piece after peeling completion was observed visually (S: small size, good peelability, B: large size, bad peelability) Table 3 shows the conditions of the peeling process. The obtained results are shown in Table 4.

<Evaluation results>
As shown in Table 4, in Examples 1 to 3, the resolution adhesion (L / S) is as good as 9 to 12 μm, the peeling time is moderately short, the size of the peeling piece is small, and the photosensitivity The balance between resolution and peelability was good. On the other hand, in Comparative Examples 1 and 2, although the peeling time was short, the resolution was not good.

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

Explanation of symbols

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

Claims (7)

(A) a binder polymer having a divalent group represented by the following general formulas (I), (II) and (III),
A photosensitive resin composition containing (B) a photopolymerizable compound, and (C) a photopolymerization initiator.

[In the formulas (I), (II) and (III), R ¹ , R ² and R ⁴ each independently represent a hydrogen atom or a methyl group, and R ³ and R ⁵ each independently have 1 to 10 carbon atoms. An alkyl group, an alkoxy group having 1 to 10 carbon atoms, a hydroxyl group, a phenyl group, a phenoxy group, a benzyl group, a phenylalkyl group, a cycloalkyl group having 5 or more carbon atoms, or a halogen atom is shown. m and n each independently represents an integer of 0 to 5, s represents an integer of 1 to 5, and when m or n is 2 to 5, a plurality of R ³ or R ⁵ may be the same or different from each other. Good. ]   The photosensitive resin composition according to claim 1, wherein the (C) photopolymerization initiator is a hexaarylbiimidazole derivative.   (D) The photosensitive resin composition of Claim 1 or 2 which further contains a sensitizing dye.   (E) The photosensitive resin composition as described in any one of Claims 1-3 which further contains an amine compound.   A photosensitive element provided with a support film and the photosensitive resin composition layer which consists of the photosensitive resin composition as described in any one of Claims 1-4 formed on the said support film. A step of laminating a photosensitive resin composition layer comprising the photosensitive resin composition according to any one of claims 1 to 4 on a circuit forming substrate,
An exposure step of irradiating a predetermined portion of the photosensitive resin composition layer with actinic rays to photo-cure an exposed portion; and the photosensitive resin composition from the circuit-forming substrate on which the photosensitive resin composition layer is laminated. A method for forming a resist pattern, comprising a developing step of removing a portion other than the exposed portion of the layer.   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 6.

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