JP5563256B2 - Photosensitive resin composition, and photosensitive film and photosensitive resist using the same - Google Patents

Description

  The present invention relates to a photosensitive resin composition, and a photosensitive film and a photosensitive resist using the same.

  Conventionally, a flexible printed circuit board (FPC) is formed into a circuit by press-punching and laminating a laminate-type insulating film in which an adhesive is applied to a polyimide film called a coverlay, and further heat-curing under pressure under a press. As a cover layer on the surface of the flexible substrate. Since this cover lay is composed of a low shrinkage thermosetting resin based on a polyimide film, the warpage after lamination and press curing is very small. The warpage during the reflow of the mounting can be extremely reduced, and it is used in a large amount for FPC applications.

However, since punching is performed with a press, fine processing is difficult, and there is a disadvantage that alignment accuracy is not good when laminating with a circuit board on which a circuit is formed.
On the other hand, an alkali-developable photosensitive resin composition and its dry film have been proposed as a photosensitive coverlay (see Patent Document 1).

  On the other hand, since FPC is mounted on an electronic device, there is a demand for flame retardancy, and this FPC is also required for a solder resist. The FPC is usually a polyimide substrate and is a thin film unlike a printed wiring board of a glass epoxy substrate. However, since the solder resist to be applied has the same film thickness on both the printed wiring board and the FPC, the burden on the solder resist is relatively increased. On the other hand, a composition of a solder resist for FPC having a compound having a halogenated aromatic ring and a polymerizable unsaturated double bond in the molecule has been proposed (see Patent Document 2). Use is not preferable from the viewpoint of environmental load.

JP 2000-131836 A JP 2007-10794 A

  In view of the above problems, the present invention has a high level of flame retardancy without using a halogen-based flame retardant for flame retardancy of a photosensitive resin composition, and has plasticity, resolution, solder heat resistance, and moisture resistance. An object of the present invention is to provide an alkali development type photosensitive resin composition capable of forming a film having excellent properties, adhesion, chemical resistance, and the like, and a flexible printed wiring board using the same.

（但し、ＲはＨまたはＣＨ_３である。）
（Ｆ）ホスファゼンオリゴマーと
を具えることを特徴とする、アルカリ現像型の感光性樹脂組成物に関する。 In order to solve the above problems, the present invention provides:
(A) a resin component having a (meth) acryloyl group and a carboxyl group in one molecule and soluble in a dilute alkali solution;
(B) a base polymer component;
(C) a photopolymerizable monomer having one or more ethylenically unsaturated groups;
(D) a photopolymerization initiator;
(E) a (meth) acrylic group-containing phosphorus compound represented by the general formula (1);

(Wherein, R is H or CH _3.)
And (F) a phosphazene oligomer . The present invention relates to an alkali-developable photosensitive resin composition.

  Moreover, this invention relates to the photosensitive film characterized by including a support body and the layer which consists of the said photosensitive resin composition formed on the said support body.

  Furthermore, this invention relates to the photosensitive resist which consists of a photocured material of the said photosensitive resin composition apply | coated on the board | substrate for printed wiring boards.

  As a result of diligent studies to solve the above-described problems, the inventors of the present invention, in a conventionally known photosensitive resin composition of the alkali development type, contains a specific (meth) acryl group instead of a halogen-containing compound. It has been found that the above-mentioned problems can be solved by using a phosphorus compound and a specific phosphazene compound in combination, and the present invention has been completed.

  As described above, the photosensitive resin composition of the present invention uses a specific (meth) acryl group-containing phosphorus compound and a specific phosphazene compound in combination with a conventionally known photosensitive resin composition. Even without the use of brominated epoxy resins or halogen flame retardants, it has a high level of flame retardancy and forms a film with excellent plasticity, resolution, solder heat resistance, adhesion, chemical resistance, etc. can do.

  Therefore, by using the photosensitive resin composition, a photosensitive film and a photosensitive resist reflecting the above-described characteristics of the photosensitive resin composition can be obtained. When producing, since no toxic gas such as hydrogen bromide or dioxins, which has been a problem at the time of combustion of the photosensitive resin composition as described above, is not generated, the environmental load can be reduced. Moreover, the patterning property and adhesiveness of the photosensitive film and the photosensitive resist with respect to a flexible printed circuit board can be improved due to the resolution and adhesiveness of the photosensitive resin composition, and further the characteristics such as plasticity.

  The details of the present invention as well as other features and advantages are described in detail below.

(Photosensitive resin composition)

(A) Resin component having (meth) acryloyl group and carboxyl group in one molecule and soluble in dilute alkaline solution (A) Resin component soluble in dilute alkaline solution is used in 1 molecule It has a (meth) acryloyl group and a carboxyl group, and is soluble in a dilute alkali solution. In this component, the (meth) acryloyl group in the molecule is polymerized by radicals generated from the photopolymerization initiator (E) described later by irradiation with active energy rays such as ultraviolet rays. As a result, the resin composition is It has an insolubilizing function.

  Such a resin component soluble in (A) a dilute alkaline solution is, for example, an epoxy acrylate compound obtained by subjecting an epoxy resin to an acrylic modification by esterifying (meth) acrylic acid and further adding an acid anhydride. (For example, an epoxy acrylate oligomer) can be used as a raw material. That is, this raw material is polymerized by radicals generated from the (E) photopolymerization initiator to become the resin component.

  As the epoxy resin constituting the epoxy acrylate compound, a known epoxy resin can be used, and a general bisphenol type epoxy resin or the like can be preferably used. Moreover, as (meth) acrylic acid, acrylic acid, methacrylic acid, and a mixture thereof can be used. Furthermore, acid anhydrides include phthalic anhydride, succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, itaconic anhydride, methylendomethylene. Tetrahydrophthalic anhydride or the like can be used, and succinic anhydride or phthalic anhydride is particularly preferable.

  In addition, (A) a resin component soluble in a dilute alkaline solution includes a polyol compound, a polybasic acid anhydride having two anhydrides in the molecule, and a (meth) acryl having one epoxy group in the molecule. It is also possible to use a carboxyl group-containing urethane compound (for example, a carboxyl group-containing urethane oligomer) obtained by reacting with an acid.

  The resin component soluble in the (A) dilute alkaline solution of the present invention preferably has an acid value in the range of 50 to 200 mg KOH / g, and (A) the acid of the resin component as a component soluble in the dilute alkaline solution If the value is less than 50 mgKOH / g, alkali solubility is lowered and alkali development becomes difficult. If it exceeds 200 mgKOH / g, the film thickness during development increases when used as an alkali development type photoresist. May significantly decrease. The acid value of the resin component soluble in the (A) dilute alkali solution is more preferably in the range of 80 to 150 mgKOH / g.

  The blending amount of the resin component soluble in the (A) dilute alkali solution is preferably 20 to 70% by mass with respect to the entire photosensitive resin composition of the present invention.

(B) Base polymer The base polymer as the component (B) of the present invention is, for example, acrylic resin, polyurethane, epoxy resin, phenoxy resin, polyester, polyamide, polyimide, polyamideimide, polyesterimide, polycarbonate, melamine resin, polyphenylene sulfide. And known resins such as polyoxybenzoyl and acid-modified resins thereof having a carboxyl group in the molecule. Among them, it is preferable to be obtained by polymerizing a monomer (polymerizable monomer) having an ethylenically unsaturated double bond (such as radical polymerization).

  Examples of the monomer having an ethylenically unsaturated double bond include acrylamides such as diacetone acrylamide, vinyl alcohol esters such as acrylonitrile and vinyl-n-butyl ether, (meth) acrylic acid alkyl esters, (meth ) Acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, (meth) acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth) acrylate, 2 , 2,3,3-tetrafluoropropyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acrylic acid, α-chloro (meth) acrylic acid, β-furyl (meth) acrylic acid, and β -(Meth) acrylates such as styryl (meth) acrylic acid Maleic acid monomers such as lauric acid monomers, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, and monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, Examples include itaconic acid, crotonic acid, and propiolic acid. These can be used alone or in combination of two or more.

  From the viewpoint of improving the photosensitivity and the resist shape after photocuring, an acrylic resin is preferred. The acrylic resin can be obtained by radical polymerization using, for example, (meth) acrylic acid and (meth) acrylic acid alkyl ester as a copolymerization component. In particular, a vinyl copolymer compound obtained by using methacrylic acid and (meth) acrylic acid alkyl ester as a copolymerization component is preferable.

  Examples of (meth) acrylic acid alkyl esters 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. Examples include esters, (meth) acrylic acid hexyl esters, (meth) acrylic acid butyl esters, (meth) acrylic acid octyl esters, and (meth) acrylic acid 2-ethylhexyl esters.

  As said vinyl type copolymer compound, you may use what is obtained by copolymerizing the vinyl monomer which can be copolymerized with these with (meth) acrylic-acid alkylester and (meth) acrylic acid. Examples of such vinyl monomers include (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, methacrylic acid glycidyl ester, 2,2,2- Examples include trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate acrylamide, diacetone acrylamide, styrene, and vinyl toluene.

  Moreover, what contains the acrylic acrylate which has an ethylenically unsaturated group as a copolymerization component as a vinyl-type copolymer compound which is an acrylic resin is applicable.

  As the base polymer, an acid-modified polyester resin is also preferable. Examples of the acid-modified polyester resin include a chain structure including an ester bond formed by a polymerization reaction between a diglycidyl ether type epoxy compound and a dibasic acid using a tertiary amine having a pKa of 9.0 or less as a catalyst. And a resin having a carboxyl group formed by adding an acid anhydride to this chain structure.

  Diglycidyl ether type epoxy compounds for forming this acid-modified polyester resin include bisphenol A type epoxy resins such as bisphenol A diglycidyl ether, bisphenol F type epoxy resins such as bisphenol F diglycidyl ether, and bisphenol S diester. Bisphenol S type epoxy resins such as glycidyl ether, biphenol type epoxy resins such as biphenyl diglycidyl ether, bixylenol type epoxy resins such as bixylenol diglycidyl ether, hydrogenated bisphenol A type epoxy resins such as hydrogenated bisphenol A glycidyl ether, These dibasic acid-modified diglycidyl ether type epoxy resins and the like can be mentioned. Among these, bisphenol A type epoxy resins are preferred because they are excellent in heat resistance and chemical resistance and do not relatively shrink due to curing. These can be used alone or in combination of two or more.

  From the viewpoint of improving alkali developability, the acid value of the base polymer is preferably 50 to 170 mgKOH / g, for example, 70 to 150 mgKOH / g in the case of an acrylic or acid-modified polyester base polymer. More preferably, it is 90-130 mgKOH / g.

  In addition, the weight average molecular weight (Mw) of the base polymer is preferably 20000 to 150,000, more preferably 40000 to 130,000, from the viewpoint of improving the coating properties and alkali developability of the photosensitive resin composition. Preferably, it is 60000-120,000. The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC) (in terms of standard polystyrene).

  (B) As a compounding quantity of a base polymer, it is preferable that it is 20-60 mass parts with respect to 100 mass parts of (A) resin components soluble in a dilute alkali solution.

(C) The photopolymerizable monomer (C) component having one or more ethylenically unsaturated groups is a compound having one or more ethylenically unsaturated groups in the molecule. This photopolymerizable monomer characterizes the photosensitivity of the photosensitive resin composition. It is polymerized by irradiation with active energy rays such as ultraviolet rays under a photopolymerization initiator, and then polymerized and cured. In addition, the above-described photosensitive film and photosensitive resist can be configured. In addition, the requirement of having one or more ethylenically unsaturated groups in the molecule is required for the photopolymerizable monomer to be bonded to the base polymer and the like and stably exist in the photosensitive resin composition. Is.

  Examples of the photopolymerizable monomer include a bisphenol A (meth) acrylate compound, a compound obtained by reacting a polyhydric alcohol with an α, β monounsaturated carboxylic acid, and a glycidyl group-containing compound with an α, β monounsaturated carpon. Examples thereof include a compound obtained by reacting an acid, a urethane monomer such as a (meth) auroot compound having a urethane bond in the molecule, or a urethane oligomer. Besides these, nonylphenoxy polyoxyethylene acrylate, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloyloxyalkyl Examples include phthalic acid compounds such as -o-phthalate, (meth) acrylic acid alkyl esters, and EO-modified nonylphenyl (meth) aclute. These may be used alone or in combination of two or more.

  In addition, it is preferable that the said (C) component contains a bisphenol A type (meth) acrylate compound from a viewpoint of making alkali developability favorable. Examples of bisphenol A-based (meth) acrylate compounds include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolypropoxy). ) Phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, and 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane Etc.

  Among the above-mentioned, it is more preferable to contain 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane. Examples of 2,2-bis (4-((meth) acryloxypolytechnoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxy dioxytoxyl) phenyl) propane, 2.2- Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meth)) 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 nonaethoxy) ) Phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl), 2,2- Bis (4-((meth) acryloxydodecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl), 2,2-bis (4-((meth) acrylic) Loxytetradecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxypentadecoxy) phenyl), and 2,2-bis (4- (meth) acryloxyhexadecaethoxy) phenyl ) And the like. You may use these individually or in combination of 2 or more types.

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

  Examples of 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydipropoxy) phenyl) propane, 2, 2-bis (4-((meth) acryloxytripropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetrapropoxy) phenyl) propane, 2,2-bis (4-(( (Meth) acryloxypentapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheppropoxy) Phenyl) propane, 2,2-bis (4-((meth) acryloxyoctapropoxy) phenyl) propane, 2,2-bis (4-((meth) a) Liloxynonapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxydecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxyundecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxydodecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxytridecapropoxy) phenyl), 2,2-bis (4- ( (Meth) acryloxytetradecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxypentadecapropoxy) phenyl) and 2,2-bis (4-((meth) acryloxyhexadeca) Propoxy) phenyl) and the like. These may be used alone or in combination of two or more.

Examples of 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxyoctapropoxy) phenyl) propane, Examples include 2,2-bis (4-((meth) acryloxytetraethoxytetrapropoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxyhexaethoxyhexapropoxy) phenyl) propane. .
These can be used alone or in combination of two or more.

  Examples of the compound obtained by reacting a polyhydric alcohol with α, β-unsaturated carboxylic acid include polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups. 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, tri Methylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO / PO-modified trimethylolpropane tri (meth) acrylate, tetramethylolmethanetri (meth) A Examples thereof include acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. These may be used alone or in combination of two or more.

“EO” refers to “ethylene oxide”, and “PO” refers to “propylene oxide”. Further, “EO modified” means having a block structure of ethylene oxide units (—CH ₂ —CH ₂ —0—), and “PO modified” means propylene oxide units (—CH ₂ —CH ₂ —CH _{2). -0 -, - CH (CH 3} ) means having a block structure of CH 2 -0-).

  Examples of compounds obtained by reacting a glycidyl group-containing compound with α, β monounsaturated carboxylic acid include trimethylolpropane triglycidyl ether tri (meth) acrylate and 2,2-bis (4- (meth) acryloxy- 2-hydroxy-propyloxy) phenyl and the like. In addition, as (alpha), (beta) -unsaturated carboxylic acid for obtaining the above compounds, (meth) acrylic acid etc. are mentioned, for example.

  Examples of urethane monomers include (meth) acrylic monomers having an OH group at the β-position, isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate. Examples include addition reaction products with diisocyanate compounds, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, and EO or PO-modified urethane di (meth) acrylate.

  Furthermore, examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, and (meth) acrylic acid 2-ethylhexyl ester. Can be mentioned. These can be used alone or in combination of two or more.

  The blending amount of the photopolymerizable monomer (C) is preferably 20 to 40 parts by mass with respect to 100 parts by mass of the resin component (A) soluble in the dilute alkali solution.

(D) Photopolymerization initiator Examples of the photopolymerization initiator (D) include, for example, benzophenone, N, N ' -tetraalkyl "4,4 ' -diaminobenzophenone, 2-benzyl-2-dimethylamino 11- Aromatic ketones such as (4-morpholinophenyl) -butanone-1 and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 4,4 ' -bis (dimethylamino ) Benzophenone (Miherer ketone), 4,4 ' -Bis (diethylamino) benzophenone, 4-methoxy-4 ' -dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1-morpholinophenone) -butanone-1,2-ethylanthraquinone And aromatics such as phenanthrenequinone Benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether, benzoins such as methyl benzoin and ethyl benzoin, benzyl derivatives such as benzyl dimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenyl Imidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (O-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer, and 2- (2,4-dimethoxyphenyl) -4 2,4,5-triaryl, such as 2,5-diphenylimidazole dimer Examples include midazole dimer, 9-phenylacridine and acridine derivatives such as 1,7-bis (9,9 ' -acridinyl) heptane, N-phenylglycine, N-phenylglycine derivatives, and coumarin compounds. These can be used singly or in combination of two or more.

  Here, the blending amount of the photopolymerization initiator (D) is preferably in the range of 1 to 20 parts by mass with respect to 100 parts by mass of the resin component soluble in the (A) dilute alkali solution.

（但し、ＲはＨまたはＣＨ_３である。）で表わされる。なお、この化合物自体は公知であって、例えば、特開平７−４８３９４号等に記載されている。 (E) (Meth) acrylic group-containing phosphorus compound (E) The (meth) acrylic group-containing phosphorus compound is represented by the general formula (1).

(Where R is H or CH ₃ ). This compound itself is known and described in, for example, JP-A-7-48394.

Specifically, it is preferable to include phosphazene oligomers represented by the following general formulas (2) and (3).

  Here, the blending amount of the (E) (meth) acrylic group-containing phosphorus compound is preferably in the range of 5 to 50 parts by mass with respect to 100 parts by mass of the resin component soluble in the (A) dilute alkali solution.

  This (meth) acrylic group-containing phosphorus compound contributes to the flame retardancy, plasticity, resolution, solder heat resistance, adhesion, chemical resistance, etc. of the photosensitive resin composition.

（但し、式中、Ｒ^２及びＲ^３は、それぞれ水素原子又はハロゲンを含まない１価の有機基であり、ｎは３〜１０の整数である。）を挙げることができ、このとき、Ｒ^２及びＲ^３の１価の有機基としてはフェニル基、アルキル基、アミノ基、アリル基等の基が好ましいものとして挙げられる。また、一般式（４）の末端基としては、水素原子、水酸基、アルキル基、アルコキシル基、アリールオキシ基、シアネート基等が挙げられる。 (F) Phosphazene Compound As the (F) phosphazene compound, known phosphazene compounds used for imparting flame retardancy can be used. For example, they are represented by the following general formulas (4) and (5). Phosphazene oligomer

(Wherein, R ² and R ³ are each a monovalent organic group not containing a hydrogen atom or halogen, and n is an integer of 3 to 10). Preferred examples of the monovalent organic group of ² and R ³ include a phenyl group, an alkyl group, an amino group, and an allyl group. Moreover, as a terminal group of General formula (4), a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxyl group, an aryloxy group, a cyanate group etc. are mentioned.

  More preferable phosphazene compounds include phosphazene oligomers such as propoxyphosphazene oligomers, phenoxyphosphazene oligomers, cyanate phenyl phosphazene oligomers, and cyanophenoxyphosphazene oligomers.

  The (F) phosphazene compound contributes to the flame retardancy, plasticity, resolution, solder heat resistance, adhesion, chemical resistance, etc. of the photosensitive resin composition.

  As the (F) phosphazene compound, a phosphazene compound having a melting point of 100 ° C. or higher can be preferably used in consideration of the above-described characteristics. This (F) phosphazene compound can be used individually or in mixture of 2 or more types.

  (F) The compounding amount of the phosphazene compound is preferably 1 to 50 parts by mass, particularly preferably 5 to 40 parts by mass with respect to 100 parts by mass of the resin component soluble in the (A) dilute alkali solution. .

Other Additives The photosensitive resin composition of the present invention preferably further contains (G) a block type isocyanate. The block type isocyanate is inactive at room temperature (20 to 30 ° C.), but is a compound that regenerates isocyanate groups by reversibly dissociating the blocking agent when heated. The dissociation temperature of the blocking agent is preferably 120 to 200 ° C.

  Examples of such isocyanate compounds include isocyanurate type, biuret type, and adduct type. Among these, the isocyanurate type is preferable from the viewpoint of improving the adhesion by the photosensitive resin composition. These can be used alone or in combination of two or more.

  Further, in the block type isocyanate compound, examples of the blocking agent bonded to the isocyanate include at least one selected from diketones, oximes, phenols, alkanols, caprolactam and the like. Specific examples include methyl ethyl ketone oxime and ε-caprolactam.

  Examples of such blocked isocyanate compounds include Duranate manufactured by Asahi Kasei Chemicals, Takenate manufactured by Takeshi Mitsui Chemicals, and the like. These can be used alone or in combination of two or more.

  When the insulating property excellent in the photosensitive resin composition is calculated | required, what contained aromatic rings, such as an isocyanur skeleton and a benzene ring, in the structure is preferable as block type isocyanate among the above-mentioned.

  (G) It is preferable that the compounding quantity of block isocyanate is the range of 5-50 mass parts with respect to 100 mass parts of (A) resin components soluble in a dilute alkali solution.

  In addition to the components (A) to (G) described above, the photosensitive resin composition may further include other components according to desired characteristics.

  As other components, first, a diluent may be mentioned. By including a diluent, the viscosity of the photosensitive resin composition is adjusted, and application on a predetermined substrate becomes easy. Examples of the diluent include aliphatic alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, n-pentanol and hexanol, hydrocarbons such as benzyl alcohol and cyclohexane, diacetone alcohol, Aliphatic ketones such as 3-methoxy-1-butanol, acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isobutyl ketone, methyl pentyl ketone, methyl hexyl ketone, ethyl butyl ketone, dibutyl ketone, ethylene glycol, diethylene glycol, tri Ethylene glycol, tetraethylene glycol, propylene glycol, ethylene glycol monoacetate, ethylene glycol diacetate, propylene glycol monoacetate, propylene Ethylene glycol alkyl ethers such as ethylene glycol diacetate, propylene glycol monoethyl ether, methyl cellosolve, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate And acetate thereof, diethylene glycol monoalkyl ethers and acetate thereof, diethylene glycol dialkyl ethers, triethylene glycol alkyl ethers, propylene glycol alkyl ethers and acetate thereof, and dipropylene glycol alkyl ethers.

  Also, petroleum solvents such as toluene, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha, ethyl formate, propyl formate, butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate Carboxylic acid esters such as ethyl propionate, methyl butyrate, and ethyl butyrate, amines, amides such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone, dimethyl sulfoxide Examples of the diluent include dioxane, tetrahydrofuran, cyclohexanone, γ-butyllactone, 3-hydroxy-2-butanone, 4-hydroxy-2-pentanone, and 6-hydroxy-2-hexanone. These can be used alone or in combination of two or more.

  Furthermore, if necessary, known and commonly used colorants such as phthalocyanine blue, phthalocyanine green, iodine green, buzisazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, hydroquinone, hydroquinone monomethyl ether, t- Known conventional polymerization inhibitors such as butylcatechol, pyrogallol, phenothiazine, etc., known thickeners such as asbestos, olben, benton, montmorillonite, antifoaming agents such as silicones, fluorines, and polymers, leveling agents, Known and commonly used additives such as imidazole, thiazole and triazole silane coupling agents can be used.

  In addition to the components described above, the photosensitive resin composition of the present invention may further include barium sulfate, barium titanate, silicon oxide powder, for the purpose of improving properties such as adhesion and hardness, Known and commonly used inorganic fillers such as finely divided silicon oxide, amorphous silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, and mica powder can be used.

(Photosensitive film and photosensitive resist)
The dry film resist formed using the photosensitive resin composition of the present invention may be a single film, or may be formed by forming the photosensitive resin composition layer of the present invention on a support film (carrier film). Furthermore, you may use as a photosensitive resin laminated body which laminated | stacked the protective film (cover film) further.

  When the photosensitive resin laminate is used, the support film is not particularly limited as long as it is transparent and flexible and can withstand coating drying. For example, a polyethylene terephthalate (PET) film or the like Polyester film, stretched polypropylene (OPP) film, and the like, preferably a PET film.

  The protective film has a role of preventing transfer of the photosensitive resin composition layer having adhesiveness to the support film when the photosensitive resin laminate is rolled, for example, a polyethylene (PE) film, Polyolefin films such as polypropylene (PP) films, PET films, fluororesin (PTFE) films, polyvinyl alcohol films, nylon films, etc. are used, preferably polyolefin films, particularly PE films.

  Since the film formed using the photosensitive resin composition of this invention is excellent in vacuum laminating property, the surface roughness of the protective film for ensuring the surface roughness of a film is not specifically limited. By using a protective film having an average roughness (Ra) of 1 or more, more reliable and excellent vacuum laminating properties can be imparted. The surface average roughness (Ra) is an average height obtained by dividing the area of the roughness curve by the measured length, as shown in JIS B O6011994.

  In the photosensitive resin laminate of the present invention, the thickness of the photosensitive resin composition layer varies depending on, for example, the thickness of the copper wiring, but is usually preferably 100 μm or less, more preferably 80 μm or less, and particularly preferably 20 to 60 μm. If the thickness of the photosensitive resin composition layer is too thick, curing due to pattern exposure tends to be insufficient at the bottom of the resist, so that there is a tendency for poor adhesion or difficulty in obtaining sufficient resolution.

  The thickness of the support film is preferably 10 to 25 μm. If the thickness of the film is too thin, the resistance of the photosensitive resin laminate itself is inferior, and the support film tends to be broken when peeled off, and if it is too thick, the support film becomes hard, due to its hardness. There is a tendency that the followability of the photosensitive resin composition layer to the conductor circuit is inferior. Moreover, the thickness of a protective film is 10-50 micrometers normally, Preferably it is 15-35 micrometers.

  Next, as an application example of the photosensitive resin composition of the present invention, a method for producing a flexible printed wiring board when the photosensitive resin laminate is used as a solder resist dry film will be described below.

〔laminate〕
First, the protective film of the photosensitive resin laminate is peeled off, and the surface of the photosensitive resin composition layer is bonded to the wiring surface of a substrate on which a conductor circuit such as FPC is formed using a laminator. It is preferable to use a vacuum laminator from the viewpoint of followability to the conductor circuit, whereby the photosensitive resin composition layer can be neatly bonded to the substrate wiring surface without involving air or the like.

〔exposure〕
Next, the pattern mask is directly contacted (adhered) on the support film on the opposite side of the photosensitive resin composition layer and exposed. In the case of proximity exposure and projection exposure, the pattern mask is exposed in a non-contact state. Furthermore, direct imaging (direct exposure) using a laser may be performed without using a pattern mask. The exposure is usually performed by ultraviolet (V) irradiation, and as a light source at that time, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, an argon laser, or the like is used.

〔developing〕
After the exposure, the support film on the photosensitive resin composition layer is peeled off, and then the unexposed portion (uncured portion) is dissolved and dispersed by development. When the photosensitive resin composition is a dilute alkali development type, a dilute aqueous solution having an alkali concentration of about 0.3 to 5% by weight such as sodium carbonate or potassium carbonate is used as the developer. In the development, a method of spraying at a uniform pressure is preferable from the viewpoint of resolution and adhesion stability. In the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for promoting development, and the like may be mixed. And after development, it is sufficiently washed with water and dried. By developing, the unexposed resist portion is dissolved to expose the lower copper pattern portion that requires plating or soldering.

[Heat cure]
In order to further enhance characteristics such as surface curability, solder heat resistance, and chemical resistance, a further crosslinking reaction step is performed. The cross-linking reaction step which becomes the thermal cure is usually performed at 100 to 180 ° C. for about 15 to 90 minutes. Before heat curing, UV curing (post-exposure) may be performed after sufficiently drying after development in order to improve characteristics such as surface curability, solder heat resistance, and chemical resistance. UV cure is usually used at 0.5 to ¹⁰ J / cm ² .

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

(Examples 1-3 and Comparative Examples 1-3)
[Preparation of photosensitive film]
First, the solution of the photosensitive resin composition was obtained by mixing the component (1) -component (7) shown in Table 1 and other components with the compounding quantity (part by weight) of the solid content shown in the table. In the table, resin (1) of component (1) is an acrylic resin, and is a copolymer of methacrylic acid, methyl methacrylate, butyl acrylate, and styrene (methacrylic acid: methyl methacrylate: butyl acrylate: Styrene = 25 wt%: 45 wt%: 15 wt%: 15 wt%) and a weight average molecular weight of 110000 and an acid value of 125 mgKOH / g. Component (1) corresponds to component (B) in the above-described embodiment.

  Moreover, BPE-500 of a component (2) is bisphenol A polyoxyethylene dimethacrylate (made by Shin-Nakamura Chemical Co., Ltd.). This corresponds to the component (C) of the photosensitive resin composition of the present invention described above. Furthermore, ZAR-2000 of component (3) has a (meth) acryloyl group and a carboxyl group in one molecule, and is a resin component soluble in a dilute alkaline solution (manufactured by Nippon Kayaku Co., Ltd., weight average) The molecular weight is 11000) and corresponds to the component (A) of the above-described photosensitive resin composition of the present invention.

  Furthermore, IRGACURE819 of the component (4) is acylphosphine oxide (manufactured by Ciba Specialty Chemicals Co., Ltd.) and corresponds to the component (d) of the above-described embodiment of the photosensitive resin composition of the present invention. Component (5), FRM-1000, is a phosphorus-containing monomer (manufactured by Nippon Kayaku Co., Ltd.) and corresponds to component (E) of the photosensitive resin composition of the present invention. Component (6), FP-300, is cyanophenoxyphosphazene (Fushimi Pharmaceutical Co., Ltd.) and corresponds to the component (F) of the photosensitive resin composition of the present invention. Component (7), TPA-B80E, is a block isocyanate (manufactured by Asahi Kasei Chemicals Corporation) and corresponds to the component (G) of the photosensitive resin composition of the present invention.

  In addition to the components (1) to (7) described above, a predetermined amount of silica as an inorganic filler, phthalocyanine blue and melamine as colorants was added as necessary. Moreover, the photosensitive resin composition was dissolved using methyl ethyl ketone as a diluent to prepare a solution.

  Next, the solution of the photosensitive resin composition was uniformly applied onto a 16 μm polyethylene terephthalate film (trade name G2-16, manufactured by Teijin Limited) as a support, and 100 ° C. using a hot air convection dryer. Was dried for 10 minutes to form a photosensitive resin composition layer on the support. The film thickness after drying of the photosensitive resin composition layer was 30 μm.

  Next, on the surface of the photosensitive resin composition layer opposite to the side in contact with the support layer, a polyethylene film (manufactured by Tamapoly Co., Ltd., trade name NF-15) is bonded as a protective film, and the photosensitive film is attached. Obtained.

[Characteristic evaluation]
Using the photosensitive films prepared in Examples 1 to 3 and Comparative Examples 1 to 3, the following tests were performed, respectively, and the plating resistance, solder heat resistance, crack resistance when each photosensitive film was used, Bleed resistance, laminate properties, resolution, etc. were evaluated. The results are summarized in Table 2.

  First, an evaluation substrate was prepared as follows using each photosensitive film. That is, first, the copper surface of a copper-clad polyimide film substrate for FPC (copper thickness 18 μm / polyimide film thickness 25 μm) was polished with an abrasive brush, washed with water, and then dried. Using this printed wiring board substrate and a 12.5 μm thick polyimide film (Kapton (registered trademark) 50 V, manufactured by Toray DuPont Co., Ltd.) using a vacuum laminator (Nichigo Morton, product name V-130) Under the conditions of a hot plate temperature of 70 ° C., a vacuum drawing time of 20 seconds, a laminating press time of 30 seconds, an atmospheric pressure of 4 kPa or less, and a pressure bonding pressure of 0.4 MPa, the polyethylene film of the photosensitive film is peeled off and laminated. Obtained.

The laminated product for evaluation after lamination was irradiated onto the entire surface with an exposure amount equivalent to 8 steps of a 21-step tablet made by Stouffer with a 2 kW ultra-high pressure mercury short arc lamp (parallel light), and 1% Na _{2 at} 30 ° C. Spray development (spray pressure 0.15 MPa) was performed twice with the CO ₃ aqueous solution for the minimum development time, followed by washing with water and drying. Subsequently, ultraviolet rays were irradiated with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd., and further subjected to a heat treatment at 170 ° C. for 60 minutes on the printed wiring board substrate. An evaluation substrate on which a solder resist was formed was obtained.

<Electroless gold plating resistance>
The evaluation substrate is plated using commercially available electroless nickel plating bath and electroless gold plating bath under the conditions of nickel 0.5 μm and gold 0.03 μm. After evaluating the presence or absence of penetration, the presence or absence of peeling of the resist layer was evaluated by tape peeling. The judgment criteria are as follows.
○: Infiltration and peeling are not seen.
X: There is peeling after soaking and plating.

<Solder heat resistance>
Using the evaluation substrate, solder heat resistance was evaluated as follows. That is, after applying rosin-based flux (trade name MH-820V, manufactured by Tamura Kaken Co., Ltd.) to the evaluation substrate, a soldering treatment was performed in which the substrate was immersed in a 260 ° C. solder bath for 30 seconds. The state of occurrence of cracks in the solder resist on the evaluation substrate subjected to solder plating in this way, and the degree to which the solder resist floated from the substrate and peeling were observed with a 100-fold metal microscope.
The results were evaluated according to the following criteria. In other words, “O” indicates that no cracking of the solder resist was observed and no solder resist was lifted or peeled off, and “X” indicates that any of them was recognized.

<Lamination>
Using a continuous press-type vacuum laminator (trade name MV-130, manufactured by Nichigo Morton Co., Ltd.) on the wiring pattern of the evaluation substrate, the press hot plate temperature is 70 ° C., the evacuation time is 20 seconds, the lamination press time is 30 seconds, and the atmospheric pressure. The polyethylene film of the photosensitive film was peeled off and laminated under conditions of 4 kPa or less and a pressure bonding pressure of 0.4 MPa. After the lamination, bubbles between the substrate of the laminate and the photosensitive resin composition layer and between the wiring patterns were visually observed and evaluated according to the following criteria. That is, “O” indicates that no bubbles were observed between the substrate and the photosensitive resin composition layer and between the wiring patterns, and “X” indicates that bubbles were observed.

<Resolution>
A pattern mask (silver salt-PET film) of line / space = 20 μm / 20 μm to 120 μm / 120 μm is brought into intimate contact with the PET film of the above evaluation laminate. The 21-step tablet was developed by irradiating with an exposure amount equivalent to 8 steps. At this time, the value of the minimum line width indicating the resolution (the value of the minimum width (μm) between the cured lines formed by development) was defined as the resolution.

<Electrical characteristics>
Using an IPC B-25 comb-type electrode B coupon instead of a copper-clad substrate, an evaluation board was produced under the above conditions, a DC 100 V bias voltage was applied to the comb-type electrode, and a constant temperature of 85 ° C. and 85% RH. The presence or absence of migration after 1000 hours was confirmed in a humidity chamber. The judgment criteria are as follows.
○: No change at all ×: Migration has occurred

<Flame retardance>
The test was conducted according to UL94 flame retardancy test.

<Bleed resistance>
The copper-clad evaluation substrate was exposed to a super accelerated high temperature high humidity life test (HAST) bath for 100 hours under the condition of 121 ° C./85% RH. After the test, the occurrence of bleeding of the resin component (flame retardant) on each evaluation substrate was observed with a 100 × microscope and evaluated according to the following criteria. That is, “o” indicates that no bleeding occurred in the photosensitive resin composition layer, and “x” indicates that bleeding did not occur.

<Warpage>
The polyimide film after thermosetting was cut into 5 cm × 5 cm, placed with the printed surface facing up, and the height of the warp of the film was measured.

<Evaluation of flexibility (fold resistance)>
A sample produced in the same manner as the sample for flame retardancy evaluation was repeatedly bent 180 ° by goblet folding several times, and the crack occurrence in the coverlay at that time was observed visually and with a 200-fold optical microscope. The number of times it did not occur was evaluated.

  As is apparent from Table 2, in Examples 1 to 3 according to the present invention, all the characteristics such as electroless gold plating resistance, which are the evaluation items described above, are excellent, and the criteria defined as described above are used. All turned out to be satisfactory.

  On the other hand, in Comparative Example 1 which does not contain the component (5) FRM-1000, it was found that the above-mentioned criteria were not satisfied in the electroless gold plating resistance and flame retardancy, and the resolution and warpage were low. Further, it was found that Comparative Example 2 which does not contain the component (6) FFL300 does not satisfy the above-mentioned criteria in solder heat resistance, electrical characteristics, and bleed resistance. Furthermore, in Comparative Example 3 which does not contain the component (5) FRM-1000 and the component (6) FFL300, it was found that the flame retardancy was particularly poor.

  The present invention has been described in detail based on the above specific examples. However, the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention.

Claims (7)

(A) a resin component having a (meth) acryloyl group and a carboxyl group in one molecule and soluble in a dilute alkali solution;
(B) a base polymer component;
(C) a photopolymerizable monomer having one or more ethylenically unsaturated groups;
(D) a photopolymerization initiator;
(E) a (meth) acrylic group-containing phosphorus compound represented by the general formula (1);

(Wherein, R is H or CH _3.)
(F) a phosphazene compound;
An alkali development type photosensitive resin composition characterized by comprising: The alkali-developable photosensitive resin composition according to claim 1, wherein the phosphazene compound is a cyanoxyphosphazene oligomer.   (B) The photosensitive polymer according to claim 1, wherein the base polymer is a vinyl copolymer compound obtained by using (meth) acrylic acid and (meth) acrylic acid alkyl ester as a copolymerization component. Resin composition.   (A) To 100 parts by mass of a resin component soluble in a dilute alkali solution, (B) 20 to 60 parts by mass of a base polymer, (C) 20 to 40 parts by mass of a photopolymerizable monomer having an ethylenically unsaturated group, (D) 1-20 mass parts of photoinitiators, (E) 5-50 mass parts of phosphorus containing monomers, (F) 5-50 mass parts of phosphazenes are characterized by the above-mentioned. The photosensitive resin composition as described in 1.   (G) The photosensitive resin composition as described in any one of Claims 1-4 characterized by further including block type isocyanate. A support;
A layer formed of the photosensitive resin composition according to any one of claims 1 to 5 formed on the support;
A photosensitive film characterized by comprising:   The photosensitive resist which consists of a photocured material of the photosensitive resin composition as described in any one of Claims 1-5 apply | coated on the board | substrate for printed wiring boards.