JP5136423B2 - Photosensitive resin composition, photosensitive element, resist pattern forming method and printed wiring board manufacturing method - Google Patents

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 process is a metal that has been coated with copper and solder after the plating process such as copper and solder is applied to the metal surface of the circuit forming substrate that is not covered with the cured resist formed after development. This is a method of etching a 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 has been 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.

  Moreover, it is important that the photosensitive resin composition is excellent in resolution and adhesion in addition to the sensitivity described above. In order to form a fine wiring circuit, it is particularly required that the cross-sectional shape of the pattern line in the patterned resist film is good. In response to such a demand, a photosensitive resin composition having high sensitivity, high resolution, and high adhesion using a specific photopolymerization initiator has been proposed (for example, see Patent Document 1).

Furthermore, there is a problem that sludge generated during the development process for forming the resist pattern reattaches to the substrate. When the sludge is reattached to the substrate, when etching is performed after the development process, the metal foil to be removed by the etching is protected by the sludge and remains on the substrate, so that a short circuit between the wirings easily occurs. Further, when plating is performed after the development step, the remaining sludge on the substrate hinders the formation of the plating, so that disconnection is likely to occur. Therefore, it is also required to sufficiently suppress the generation of sludge in the development process.
International Publication No. 06/38279 Pamphlet

  However, in the case of the conventional photosensitive resin composition, when a high-density resist pattern is formed by the direct drawing exposure method, the resolution and the adhesion of the resist pattern to the circuit forming substrate are still not sufficient. . Further, it is desired to improve the removal of sludge generated during the development process. It is also desired to suppress development residues such as small pieces adhering to the resist pattern surface after development.

  Accordingly, the present invention provides a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a printed wiring that are sufficiently effective in improving resolution, adhesion, removal of sludge generated during the development process, and suppressing development residue. It aims at providing the manufacturing method of a board.

  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 and the photopolymerization initiator. As a result, by using a specific binder polymer and combining it with a photopolymerization initiator having a specific structure, it has sufficiently high resolution and adhesion without impairing sufficiently high sensitivity, and sludge generated during development. The present inventors have found that a photosensitive resin composition that is sufficiently effective for the removal property and the suppression of development residue can be obtained, and the present invention has been completed.

式（Ｉ）、式（ＩＩ）、及び式（ＩＩＩ）中、Ｒ^１，Ｒ^３，及びＲ^５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、アルコキシ基、ＯＨ基又はハロゲン原子を示し、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。 That is, the present invention is represented by (A) a divalent group represented by the following general formula (I), a divalent group represented by the following general formula (II), and the following general formula (III). have a divalent group that, hexa having a weight average molecular weight of 20000 to 50000 der Ru binder polymer, (B) a photopolymerizable compound, and (C) is one or more 1-5 alkoxy group having a carbon A photosensitive resin composition containing a photopolymerization initiator containing an arylbiimidazole compound.

In formula (I), formula (II), and formula (III), R ¹ , R ³ , and R ⁵ each independently represent a hydrogen atom or a methyl group, and R ² and R ⁴ each independently represent 1 carbon atom. -3 alkyl group, alkoxy group, OH group or halogen atom, m or n each independently represents an integer of 0-5, and when m or n is 2-5, a plurality of R ² or R ⁴ are They may be the same or different from each other.

  The photosensitive resin composition of the present invention can be formed with a sufficient resolution and adhesion even in the formation of a resist pattern by a direct drawing exposure method by being configured by combining specific components as described above. In addition, it is sufficiently effective in removing sludge generated during the development process. By using a binder polymer having a specific group such as the component (A) and a photopolymerization initiator containing a specific hexaarylbiimidazole compound such as the component (C), the resolution as described above, The present inventors consider that sufficient effects have been obtained in improving adhesion and sludge removal and suppressing development residue.

式（Ｖ）及び式（ＶＩ）中、Ｒ^６〜Ｒ^３５はそれぞれ独立に水素原子、ハロゲン原子又は炭素数１〜５のアルコキシ基を示し、同一分子中にＲ^６〜Ｒ^３５が複数存在するときそれらは同一でも異なっていてもよく、Ｒ^６〜Ｒ^３５の少なくとも１つは炭素数１〜５のアルコキシ基を示す。In the photosensitive resin composition according to the present invention, the photopolymerization initiator preferably contains one or more compounds represented by the following general formula (IV).
Z ¹ -Z ² (IV)
In formula (IV), Z ¹ and Z ² each independently represent a monovalent group represented by the following general formula (V) or (VI).

In formula (V) and formula (VI), R ^{6 to} R ³⁵ each independently represent a hydrogen atom, a halogen atom or an alkoxy group having 1 to 5 carbon atoms, and a plurality of R ^{6 to} R ³⁵ are present in the same molecule. Sometimes they may be the same or different, and at least one of R ^{6 to} R ³⁵ represents an alkoxy group having 1 to 5 carbon atoms.

  Thereby, the resolution of the photosensitive resin composition is increased, and the adhesion and sludge removability are further improved.

  The photosensitive resin composition according to the present invention 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 near the specific wavelength range, and the sensitivity of the photosensitive resin composition is improved.

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

  Moreover, this invention is a photosensitive element provided with the photosensitive resin composition layer containing the said photosensitive resin composition formed on the support film and 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 should be performed with sufficient resolution and adhesion. It is also possible to improve the removal of sludge generated during the development process and to suppress development residues.

  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 resist pattern with resolution and adhesion can be formed. In addition, sludge generated during the development process can be reliably removed.

  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, a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a printed wiring that are sufficiently effective in improving resolution, adhesion, removal of sludge generated during the development process, and suppressing development residue. A method for manufacturing a plate can be provided.

It is a schematic cross section which shows suitable one 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.

  Hereinafter, 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.

  The photosensitive resin composition of the present invention comprises (A) a divalent group represented by the above general formula (I) (hereinafter also referred to as “structural unit”) and a structure represented by the above general formula (II). A binder polymer having a unit and the structural unit represented by the general formula (III), (B) a photopolymerizable compound, and (C) a hexaarylbiphenyl having one or more alkoxy groups having 1 to 5 carbon atoms. It is the photosensitive resin composition containing the photoinitiator containing an imidazole compound.

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

  The binder polymer as component (A) is a structural unit based on styrene or a styrene derivative represented by the above general formula (I), benzyl (meth) acrylate or (meth) acrylic represented by the above general formula (II) It contains a structural unit based on an acid benzyl derivative and a structural unit based on (meth) acrylic acid represented by the above general formula (III). Thereby, both the adhesiveness with respect to the circuit formation board | substrate of a photosensitive resin composition layer which uses a photosensitive resin composition as a constituent material, and peeling characteristics can be made favorable.

Here, in the above formula (I), ^{R 1} represents a hydrogen atom or a methyl group, ^{R 2} 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.

Further, in the above 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 Represents an integer of 0 to 5.

In the above formula (III), R ⁵ represents a hydrogen atom or a methyl group, and specifically a structural unit based on acrylic acid or methacrylic acid.

  The content ratio of the structural unit represented by the general formula (I) is preferably 10 to 60% by mass, more preferably 15 to 50% by mass, more preferably 20 to 50% in the total amount of the component (A). It is particularly preferable that the content is% by mass. The content of the structural unit represented by the general formula (II) is preferably 10 to 60% by mass, more preferably 15 to 50% by mass, based on the total amount of the component (A), and 20 It is especially preferable that it is -50 mass%. The content of the structural unit represented by the general formula (III) is preferably 20 to 50% by mass, more preferably 23 to 40% by mass, based on the total amount of the component (A), 25 It is especially preferable that it is -35 mass%. If the blending amount of the structural unit based on styrene or a styrene derivative, the structural unit based on benzyl (meth) acrylate or the benzyl derivative (meth) acrylate is less than 10% by mass, the resolution tends to be inferior. When the amount exceeds 60% by mass, the peeled piece becomes large and the peeling time tends to be long. Moreover, when the blending amount of the structural unit based on (meth) acrylic acid is less than 20% by mass, the alkali solubility is inferior, the peeling piece tends to be large, and the stripping time tends to be long. If it exceeds, the resolution tends to decrease. The photosensitive resin composition using the binder polymer of the present invention has excellent effects in adhesion, resolution, removal of sludge generated during development, and suppression of development residue.

  In the present invention, the “styrene derivative” refers to a compound in which a hydrogen atom in styrene is substituted with a substituent (an organic group such as an alkyl group or a halogen atom).

  When forming the photosensitive resin composition layer using this binder polymer, one type of binder polymer may be used alone, or two or more types of binder polymers may be used in any combination. As a binder polymer in the case of using two or more types in combination, for example, two or more types of binder polymers comprising different copolymerization components (including different repeating units as constituent components), two or more types of binders having different weight average molecular weights Examples thereof include polymers and two or more types of binder polymers having different degrees of dispersion. In addition, a polymer having a multimode molecular weight distribution described in JP-A No. 11-327137 can also be used.

  (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 the 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.

  The binder polymer of the present invention can be produced, for example, by radical polymerization of a polymerizable monomer. Examples of the polymerizable monomer that gives the structural units represented by the general formulas (I) to (III) include styrene and / or styrene derivatives, benzyl (meth) acrylate and / or benzyl (meth) acrylate. Derivatives, (meth) acrylic acid.

  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 structural units other than the structural units represented by the general formulas (I) to (III) include acrylamides 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) ac Maleic acid monoesters such as phosphoric acid, β-styryl (meth) acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic Acid, itaconic acid, crotonic acid, propiolic acid and the like 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 (VII), and compounds obtained by substituting a hydroxyl group, an epoxy group, a halogen group or the like on the alkyl group of these compounds. .
^{_{CH 2 = C (R 36)}} -COOR 37 (VII)

Here, in the general formula ^{(VII), R 36} represents a hydrogen atom or a methyl ^{group, R 37} represents an alkyl group having 1 to 12 carbon atoms. Examples of the alkyl group having 1 to 12 carbon atoms represented by R ³⁷ 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 monomer represented by the general formula (VII) include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid butyl ester, (Meth) acrylic acid pentyl ester, (meth) acrylic acid hexyl ester, (meth) acrylic acid heptyl ester, (meth) acrylic acid octyl ester, (meth) acrylic acid 2-ethylhexyl ester, (meth) acrylic acid nonyl ester, (Meth) acrylic acid decyl ester, (meth) acrylic acid undecyl ester, (meth) acrylic acid dodecyl ester, and the like. These monomers can be 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 (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 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. More preferably, it is 40-60 mass parts especially 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) A component can be used individually by 1 type or in combination of 2 or more types.

  Further, the photosensitive resin composition of the present invention may be used in combination with a resin other than the component (A), for example, an acrylic resin, a styrene resin, an epoxy resin, an amide resin, an amide epoxy resin. Further, alkyd resins, phenol resins and the like can be used in combination. Of these, acrylic resins are preferred from the standpoint of alkali developability. Moreover, these resin can be used individually 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 a urethane bond in the molecule, nonylphenoxypolyethyleneoxyacrylate, phthalic acid compounds, (meth) acrylic acid alkyl esters, etc. Is 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, and the like. 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 and the like.

  The 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is obtained by using BPE-500 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) or FA-321M (product manufactured by Hitachi Chemical Co., Ltd.). 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 an OH group at the β-position and a diisocyanate compound (isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate). , 1,6-hexamethylene diisocyanate, etc.), tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, EO, PO-modified urethane di (meth) acrylate Etc. Examples of the EO-modified urethane di (meth) acrylate include UA-11 (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name). 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. -Phthalate etc. are mentioned. 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 or a (meth) acrylate compound having a urethane bond in the molecule from the viewpoint of plating resistance and adhesion. Moreover, it is preferable that a bisphenol A type (meth) acrylate compound is included from a viewpoint which can improve a sensitivity and a resolution.

  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.

で表される化合物、下記一般式（ＩＸ）：

で表される化合物、及び下記一般式（Ｘ）：

で表される化合物などが挙げられる。ここで、式（ＶＩＩＩ）、式（ＩＸ）及び式（Ｘ）中、Ｒ^３６〜Ｒ^４１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ることができる。The polyalkylene glycol di (meth) acrylate having both an ethylene glycol chain and a propylene glycol chain in the molecule in the component (B) is, for example, the following general formula (VIII):

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

And the following general formula (X):

The compound etc. which are represented by these are mentioned. Here, in formula (VIII), formula (IX), and formula (X), R ^{36 to} R ⁴¹ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, EO represents an ethylene glycol chain, PO represents a propylene glycol chain, and m ^{1 to} m ⁴ and n ^{1 to} n ⁴ 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 (VIII) to (X) include a methyl group, an ethyl group, an n-propyl group, and an i-propyl group.

The total number (m ¹ + m ² , m ³ and m ⁴ ) of ethylene glycol chain repeats in the above general formulas (VIII) to (X) 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.

The repeating number total number of propylene glycol chain in the above general formula ^{(VIII) ~ (X) (} n 1, n 2 + n 3 and ^{n 4)} is an integer of 1 to 30, an integer of 5-20 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 (VIII) include, for example, vinyl having R ³⁶ = R ³⁷ = methyl group, m ¹ + m ² = 4 (average value), and n ¹ = 12 (average value). And a compound (trade name FA-023M, manufactured by Hitachi Chemical Co., Ltd.). Specific examples of the compound represented by the general formula (IX) include, for example, R ³⁸ = R ³⁹ = 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. Furthermore, specific examples of the compound represented by the general formula (X) include, for example, vinyl having R ⁴⁰ = R ⁴¹ = 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 can be 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) A component can be used individually by 1 type or in combination of 2 or more types.

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

(C) The photoinitiator which is a component contains the hexaaryl biimidazole compound which has 1 or more of C1-C5 alkoxy groups. Specifically, in the formula (V) and the formula (VI) represented by the formula (IV), R ^{6 to} R ³⁵ are each independently a hydrogen atom, a halogen atom, or a carbon number of 1 to 5 And at least one of R ^{6 to} R ³⁵ preferably contains an alkoxy group having 1 to 5 carbon atoms. The hexaarylbiimidazole compound may have one or more alkoxy groups having 1 to 5 carbon atoms, but preferably has two or more, more preferably four or more. If this alkoxy group having 1 to 5 carbon atoms is not contained, the adhesion, resolution, sludge removability and development residue suppressing effect cannot be obtained. Examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group, and structural isomers thereof. Among these, it is preferable that it is C1, ie, a methoxy group. Moreover, it is preferable that a hexaaryl biimidazole compound contains both a C1-C5 alkoxy group and a halogen atom from a viewpoint which can improve the adhesiveness, the resolution, sludge removal property, and the inhibitory effect of a development residue further. Further, when there are a plurality of R ^{6 to} R ³⁵ in the same molecule, they may be the same or different. In the present specification, the groups represented by “R ^{6 to} R ³⁵ ” are R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ^15. , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ , R ³² , R ³³ , R ³⁴ , or R ³⁵ is shown.

  Examples of the hexaarylbiimidazole compound having one or more alkoxy groups having 1 to 5 carbon atoms include 2- (o-chlorophenyl) -4,5-bis (m-methoxyphenyl) imidazole dimer, 2 -(O-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-bis (o-chlorophenyl) -5- (3,4-dimethoxyphenyl) imidazole dimer, and the like. Moreover, it is preferable to use the compound obtained by the cross-coupling reaction containing the hexaaryl biimidazole compound which has one or more C1-C5 alkoxy groups, for example, 2- (o-chlorophenyl) -4,5- Compound obtained by coupling reaction of diphenylimidazole monomer and 2,4-bis (o-chlorophenyl) -5- (3,4-dimethoxyphenyl) imidazole monomer, 2,2 ′, 4-tris (o -Chlorophenyl) -4 ', 5'-diphenyl-5- (3,4 dimethoxyphenyl) -biimidazole and the like. In addition, the photosensitive resin composition of the present invention is combined with a photopolymerization initiator other than the hexaarylbiimidazole compound having one or more alkoxy groups having 1 to 5 carbon atoms, as long as the characteristics are not impaired. Can be blended.

  Photopolymerization initiators other than hexaarylbiimidazole compounds having one or more alkoxy groups include benzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl- Aromatic ketones such as 1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, quinones such as alkylanthraquinones, benzoin ether compounds such as benzoin alkyl ether, benzoin compounds such as benzoin and alkylbenzoin, benzyl Does not contain alkoxy groups such as benzyl derivatives such as dimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer 2,4,5-triary Imidazole dimer, 9-phenyl acridine, 1,7 (9,9'-acridinyl) include acridine derivatives such as heptane.

  The content ratio of the hexaarylbiimidazole compound having one or more alkoxy groups having 1 to 5 carbon atoms in the photopolymerization initiator as the component (C) is 10 to 100% by mass in the total amount of the component (C). It is preferable that it is 30-100 mass%, and it is especially preferable that it is 50-100 mass%. If the blending amount is less than 10% by mass, high sensitivity and high resolution tend not to be obtained.

  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 this amount is less than 0.1 parts by mass, good sensitivity and resolution tend not to be obtained, and if it exceeds 10 parts by mass, a good shape tends not to be obtained. (C) A component can be 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. Examples of the sensitizing dye as component (D) include dialkylaminobenzophenones, pyrazolines, anthracene, coumarins, xanthones, oxazoles, benzoxazoles, thiazoles, benzothiazoles, triazoles, and stilbenes. , Triazines, thiophenes, naphthalimides and the like. Further, as the sensitizing dye, a compound having a maximum absorption wavelength of 370 to 420 nm is preferable. By using such a sensitizing dye, it has sufficiently high sensitivity to the exposure light of the direct drawing exposure method. Is possible. 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. As the sensitizing dye having a maximum absorption wavelength of 370 to 420 nm, for example, pyrarizones, anthracenes, coumarins, xanthones and the like are preferable. It is preferable that the compounding quantity of the said sensitizing dye is 0.01-10 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, and it is 0.05-5 mass parts. More preferred is 0.1 to 2 parts by mass. If this amount is less than 0.01 parts by mass, good sensitivity and resolution tend not to be obtained, and if it exceeds 10 parts by mass, a good shape tends not to be obtained. (D) A component can be used individually by 1 type or in combination of 2 or more types.

  Examples of the amine compound as the component (E) include bis [4- (dimethylamino) phenyl] methane, bis [4- (diethylamino) phenyl] methane, and leuco crystal violet. The blending amount is preferably 0.01 to 10 parts by mass, 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). It is especially preferable that it is 1-2 mass parts. If the blending amount is less than 0.01 parts by mass, good sensitivity tends not to be obtained, and if it exceeds 10 parts by mass, there is a tendency to deposit as foreign matter after film formation. (E) A component can be 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 can 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 polypropylene films such as Alfan 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. Examples thereof include, but are not limited to, polyethylene terephthalate films such as PS-25 (trade name) and HTF-01 and HTR-02 (trade name) manufactured by Teijin DuPont Co., Ltd.

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

  Moreover, 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, and examples of the UV spectrometer include a 228A type W beam spectrophotometer manufactured by Hitachi, Ltd.

  The protective film 4 preferably has a smaller adhesive strength between the photosensitive resin composition layer 3 and the protective film 4 than the adhesive strength between the photosensitive resin composition layer 3 and the support film 2, and has a low fish eye. A film is 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 polyethylene films such as NF-13 and NF-15 (above, trade names) manufactured by Tamapoly Co., Ltd., Alfane MA-410, E-200C (above, manufactured by Oji Paper Co., Ltd.) (Trade name), polypropylene films such as Shin-Etsu Film Co., Ltd., and polyethylene terephthalate films such as Teijin Limited PS series (eg, PS-25, trade name), etc. is not.

  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.

  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.

As a method of laminating the photosensitive resin composition layer on the circuit forming substrate in the laminating step, for example, the protective film is gradually peeled off from the photosensitive resin composition layer and simultaneously exposed to light. Laminate by bonding the surface of the resin composition layer to the circuit forming surface of the circuit forming substrate and pressing the photosensitive resin composition layer onto the circuit forming substrate while heating the photosensitive resin composition layer. The method of doing is mentioned. In addition, it is preferable to laminate | stack this operation under pressure reduction from the viewpoint of adhesiveness and followable | trackability. In the lamination of the photosensitive element, the photosensitive resin composition layer and / or the circuit forming substrate is preferably heated to 70 to 130 ° C., and the pressure bonding pressure is about 0.1 to 1.0 MPa (1 to 10 kgf / cm). it is preferably about ^2), but not particularly limited to these conditions. Further, if the photosensitive resin composition layer is heated to 70 to 130 ° C. as described above, it is not necessary to pre-heat the circuit forming substrate in advance, but in order to further improve the laminating property, 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 developing solution, a safe and stable solution having good operability such as an alkaline aqueous solution is used. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium, or potassium hydroxide, alkali carbonates such as lithium, sodium, potassium, or ammonium carbonate or bicarbonate, potassium phosphate, and phosphoric acid. Alkali metal phosphates such as sodium, 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 can 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 performing 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.

(Preparation of photosensitive resin composition)
The following material was mix | blended and the solution of the photosensitive resin composition of Examples 1-4 and Comparative Examples 1-6 was prepared.
<Binder polymer>
Binder polymer solution (solid component: solid component and mass ratio shown in Table 2, solvent (mass ratio): methyl cellosolve / toluene (3/2), polymer weight average molecular weight: 30000, solid content acid value: Examples 1-4 Comparative Examples 1, 2 and 6 were 196 mg KOH / g, Comparative Examples 3 to 5 were 163 mg KOH / g): 113 g (solid content 54 g)
The polymer weight average molecular weight was measured by gel permeation chromatography (GPC), and calculated by conversion using a standard polystyrene calibration curve. The GPC conditions are shown below.
Pump: Hitachi L-6000 type (manufactured by Hitachi, Ltd.)
Column: Gelpack GL-R420 + Gelpack GL-R430 + Gelpack GL-R440 (3 in total) (above, manufactured by Hitachi Chemical Co., Ltd., trade name)
Eluent: Tetrahydrofuran Measurement temperature: 40 ° C
Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI (manufactured by Hitachi, Ltd.)
<Photopolymerizable compound>
2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane (FA-321M, manufactured by Hitachi Chemical Co., Ltd.): 31 g
A compound represented by the above general formula (IX), wherein R ³⁸ and R ³⁹ are each a methyl group, m ³ = 6 (average value), and n ² + n ³ = 12 (average value) (FA) -024M, manufactured by Hitachi Chemical Co., Ltd.): 15g
<Photopolymerization initiator>
Photopolymerization initiator and mass ratio shown in Table 2 (The composition of each photopolymerization initiator is shown in Tables 3 to 5. Table 3 shows the composition of TCDM-HABI, and Table 4 shows the composition of CDM-HABI. Table 5 shows the composition of B-CIM (trade name, manufactured by Hampford).
<Sensitizing dye>
9,10-dibutoxyanthracene (manufactured by Kawasaki Kasei Kogyo Co., Ltd., wavelengths [λn] = 368 nm, 388 nm, 410 nm showing absorption maximum): 0.8 g
<Coloring agent>
Leuco Crystal Violet (manufactured by Yamada Chemical Co., Ltd.): 0.25g
<Dye>
Malachite Green (Osaka Organic Chemical Industry Co., Ltd.): 0.03g
<Solvent>
Acetone 9g
Toluene 5g
Methanol 5g

(Production of photosensitive element)
The obtained solution of each photosensitive resin composition was uniformly coated on a 16 μm-thick polyethylene terephthalate film (trade name: HTF-01, manufactured by Teijin DuPont Co., Ltd.) serving 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. Subsequently, a protective film (manufactured by Tamapoly Co., Ltd., trade name: NF-15) was laminated on the photosensitive resin composition layer by roll pressurization, and photosensitivity according to each of Examples 1 to 4 and Comparative Examples 1 to 6. A sex element was obtained.

(Preparation of test piece)
Subsequently, a brush equivalent to # 600 is applied to the copper surface of a copper clad laminate (made by Hitachi Chemical Co., Ltd., trade name MCL-E-67) which is a glass epoxy material in which copper foil (thickness 35 mm) is laminated on both sides. Polishing was performed using a polishing machine (manufactured by Sankei Co., Ltd.), washed with water, and 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 manufactured by Hitachi Via Mechanics Co., Ltd. using a 405 nm blue-violet laser diode as a light source, a photosensitive resin composition layer through a phototool and a support film at an exposure amount of 50 mJ / cm ² Exposed (drawn). The illuminance was measured using an ultraviolet illuminometer (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. The obtained results are shown in Table 2.

<Resolution (missability)>
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. The obtained results are shown in Table 2.

<Adhesion>
The adhesion was exposed using a photo tool having a wiring pattern having a line width / space width of 6/6 to 30/30 (unit: μm) as an adhesive evaluation negative. Here, the adhesion has the smallest value (unit: line width / space width) such that an unexposed portion can be removed cleanly by a development process after exposure, and the line is generated without meandering or chipping. μm) was used as an index of adhesion. The smaller the numerical value, the better the evaluation of adhesion. The obtained results are shown in Table 2.

<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.

<Sludge removal performance>
Sludge removability was evaluated by the following method. First, 0.6 m ² of the photosensitive resin composition layer from which the protective film in each photosensitive element has been removed is dissolved in 1 L of a 1% Na ₂ CO ₃ aqueous solution and stirred for 90 minutes with a small developing spray circulator. Then, after the stirred solution is transferred to a plastic bottle and left for one week, the flow of sludge (sediment) at the bottom is compared before and after shaking the plastic bottle. Was judged. The higher the numerical value, the better the sludge removability, and 4 means complete removal.

<Development residue>
The development residue was determined on the resist pattern surface after development using a scanning electron microscope (trade name: Hitachi scanning electron microscope S-500A) as follows. It is desirable that there is almost no development residue.
A: There is almost no development residue with small pieces attached B: There are some development residues with small pieces attached C: There are many development residues with small pieces attached

<Evaluation results>
As shown in Table 2, the photosensitive resin compositions according to Examples 1 to 4 gave good results in all evaluations of step number sensitivity, adhesion, resolution, sludge removal, and resist shape. It was. On the other hand, the photosensitive resin compositions according to Comparative Examples 1 to 6 are inferior to the examples in at least one of the evaluations of step number sensitivity, adhesion, resolution, sludge removal, and resist shape. As a result.

  According to the present invention, a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a printed wiring that are sufficiently effective in improving resolution, adhesion, removal of sludge generated during the development process, and suppressing development residue. A method for manufacturing a plate can be provided.

Claims (7)

(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 weight average molecular weight of 20,000 to 50,000,
(B) a photopolymerizable compound, and (C) a photopolymerization initiator containing a hexaarylbiimidazole compound having one or more alkoxy groups having 1 to 5 carbon atoms,
Containing a photosensitive resin composition.

[In Formula (I), Formula (II), and Formula (III), R ¹ , R ³ , and R ⁵ each independently represent a hydrogen atom or a methyl group, and R ² and R ⁴ each independently represent carbon number. 1 to 3 alkyl groups, C1 to C3 alkoxy groups, OH groups or halogen atoms, m or n each independently represents an integer of 0 to 5, and when m or n is 2 to 5, R ² or R ⁴ may be the same as or different from each other. ] The photosensitive resin composition of Claim 1 in which the said photoinitiator contains 1 or more types of compounds represented by the following general formula (IV).
Z ¹ -Z ² (IV)
[In Formula (IV), Z ¹ and Z ² each independently represent a monovalent group represented by the following General Formula (V) or (VI). ]

[In Formula (V) and Formula (VI), R ^{6 to} R ³⁵ each independently represent a hydrogen atom, a halogen atom or an alkoxy group having 1 to 5 carbon atoms, and a plurality of R ^{6 to} R ³⁵ exist in the same molecule. When they are, they may be the same or different, and at least one of R ^{6 to} R ³⁵ represents an alkoxy group having 1 to 5 carbon atoms. ] (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 the photosensitive resin composition layer containing the photosensitive resin composition as described in any one of Claims 1-4 formed on the support film and 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 4 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 manufacturing 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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