JP2006349814A - Photosensitive resin composition, and method for manufacturing resist pattern and method for manufacturing flexible wiring board using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition showing little warpage when the composition is cured and resulting favorable workability upon mounting components, and having excellent folding durability, photosensitive characteristics, electric corrosion resistance, and PCT resistance, and to provide a method for manufacturing a resist pattern and a method for manufacturing a flexible wiring board using the composition. <P>SOLUTION: The photosensitive resin composition comprises: an acid-modified vinyl epoxy resin (A) which is an addition reaction product prepared by reacting a reactive elastomer component (b) and an unsaturated monocarboxylic acid component (c) with an epoxy resin (a) expressed by formula (1), wherein R represents a hydrogen atom or a substituent expressed by formula (1a), to obtain an esterified product, and further adding a saturated or unsaturated polybasic acid anhydride (d) to the above esterified product; a photo initiator (B); an epoxy resin (C); and an epoxy group-containing polyamide imide resin (D). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition, a method for producing a resist pattern using the same, and a method for producing a flexible wiring board.

  The solder resist is used as a solder protective film formed on the outermost layer of the printed circuit board. Conventionally, the method of forming a resist pattern by printing a thermosetting type by screen printing method has been the mainstream, but since the density of printed circuit board wiring has become higher, the resolution has become limited. Photosensitive solder resists that form patterns in the mainstream have become mainstream. Among them, the alkali developing type that can be developed with a weak alkaline solution such as a sodium carbonate solution is excellent in terms of the preservation of the working environment and the global environment, and has become the current mainstream. As a representative example of such an alkali developing type photosensitive solder resist, a photosensitive resin composition disclosed in Japanese Patent Application Laid-Open No. 1-54390, which is mainly composed of a phenol novolak type or cresol novolak type epoxy acrylate, is widely known. It has been.

  A printed circuit board with a photosensitive solder resist is formed through a photomask in which a photosensitive resin composition layer is formed on an insulating substrate on which a conductor circuit pattern is formed, and a conductor portion that is electrically connected to an electronic component is provided with a shielding portion. The exposed portion is photocured by irradiating with ultraviolet rays, and after selectively removing the photosensitive resin composition of the shielding portion (unexposed portion) by development with a weak alkaline solution, a predetermined thermosetting treatment is performed. Manufactured.

As a method of forming a photosensitive resin layer on an insulating substrate on which a conductor circuit pattern is formed, a liquid photosensitive resin composition is screen-printed, roll-coated, curtain-coated, or the photosensitive resin composition is previously prepared. There exists the method of apply | coating on a heat resistant resin film, forming into a film, and bonding together by lamination. In terms of printed circuit board productivity, the method of laminating a film can form both sides of the photosensitive resin layer at the same time than the method of directly applying a liquid material to the substrate, there is no air bubbles or foreign matter mixing when forming the solder resist layer, It is advantageous in that there is no contamination of the workplace with organic solvents, but liquid materials (liquid solder resists) are used for reasons such as coating the thickness according to the application, low material costs, and excellent film properties. The majority of manufacturers use it.
JP-A-1-54390

  For the photosensitive solder resist, there has been no emphasis so far other than the characteristics as a pattern formation by photographic method and a solder protective film. However, with the recent enhancement of functionality of electronic devices, the other characteristics are also emphasized. It has become like this. Small information terminal devices represented by mobile phones have been rapidly reduced in weight, size and functionality since the latter half of the 1990s, and techniques for mounting electronic components at high density in a narrow space have been actively studied. As a result, it has been found that COF mounting, in which a semiconductor chip is mounted on a flexible wiring board, is extremely advantageous for high-density mounting, and is being adopted and studied by various electronic component manufacturers. However, there are still many problems in COF mounting. One of the problems is that the characteristic of the photosensitive solder resist formed on the outermost layer of the flexible wiring board is low.

  Specifically, a photosensitive solder resist mainly composed of phenol novolac type or cresol novolac type epoxy acrylate, which is currently mainstream, represented by JP-A-1-54390, has a warpage amount of the substrate when thermally cured. Since it is as large as about 5 mm, it is known that there is a problem in the alignment accuracy of the substrate during COF mounting, and it is known that the folding resistance is low, and improvement of these characteristics has been demanded. For the purpose of satisfying these characteristics, there has been an attempt to increase the acid value of the epoxy acrylate by lowering the blending ratio of the phenol novolac type or cresol novolac type epoxy acrylate that is a photocurable component. In this method, it is difficult to achieve both warpage characteristics, folding resistance and photosensitive characteristics, electric corrosion resistance, PCT resistance, and the like. The object of the present invention is a photosensitive resin composition having a small amount of warping when cured, good workability at the time of component mounting, and excellent folding resistance, photosensitive characteristics, electric corrosion resistance, and PCT resistance, and the use thereof. The object is to provide a method for producing a resist pattern and a method for producing a flexible wiring board.

That is, the present invention is as follows.
1. The esterified product obtained by reacting the reactive elastomer component (b) and the unsaturated monocarboxylic acid component (c) with the epoxy resin (a) represented by the general formula (1) is further saturated or unsaturated polybasic acid anhydride. Photosensitive resin comprising acid-modified vinyl epoxy resin (A), photoinitiator (B), epoxy resin (C), and epoxy group-containing polyamideimide resin (D) as an addition reaction product to which (d) is added Composition.

（Ｒは、水素原子あるいは一般式（１ａ）示される置換基である）

(R is a hydrogen atom or a substituent represented by the general formula (1a))

2. Item 2. The photosensitive resin according to Item 1, wherein the reactive elastomer component (b) is a low molecular weight polymer component having a carboxyl group at both molecular ends and containing a butadiene skeleton and having an average molecular weight of 500 to 5,000. Composition.
3. The epoxy group-containing polyamideimide resin (D) comprises a carboxyl group-terminated polyamideimide resin (e) having at least one polymer unit selected from a polyalkylene oxide unit and a polycarbonate unit in the molecular structure, and an epoxy resin (f). Item 3. The photosensitive resin composition according to Item 1 or 2, which is an epoxy group-containing polyamideimide resin obtained by reacting with an epoxy group / carboxyl group molar ratio greater than 1.
4). Item 4. The photosensitive property according to any one of Items 1 to 3, wherein the epoxy group-containing polyamideimide (D) is 20 to 50 parts by weight with respect to 100 parts by weight of the solid content of the acid-modified vinyl epoxy resin (A). Resin composition.
5. Item 5. The photosensitive resin composition according to any one of Items 1 to 4, which has a tensile elastic modulus at ordinary temperature (25 ° C.) of 1500 MPa or less and a tensile elongation of 10 to 30% when heated and cured.
6). The photosensitive resin composition according to any one of Items 1 to 5, wherein the photosensitive resin composition is laminated on a film substrate, an ultraviolet ray is irradiated onto an image to photocur an exposed portion, and an unexposed portion is selectively removed by development. A method for producing a resist pattern.
7). A method for producing a flexible wiring board, wherein a permanent mask is formed by the method for producing a resist pattern according to Item 6.

  A photosensitive resin composition having a small amount of warping when cured, good workability at the time of component mounting, and excellent in folding resistance, photosensitive characteristics, electric corrosion resistance, and PCT resistance, and a method of producing a resist pattern using the same And it became possible to provide the manufacturing method of a flexible wiring board.

  In the present invention, the epoxy resin (a) represented by the general formula (1) is further saturated or unsaturated to an esterified product obtained by reacting a reactive elastomer component (b) and an unsaturated monocarboxylic acid component (c). Photosensitivity comprising acid-modified vinyl epoxy resin (A), photoinitiator (B), epoxy resin (C), and polyamideimide resin (D), which are addition reaction products to which polybasic acid anhydride (d) is added. The resin composition is provided.

  Examples of the epoxy resin (a) which is a raw material of the acid-modified vinyl epoxy resin (A) used in the present invention include an epoxy resin containing a bisphenol F type skeleton and a phenol novolak type skeleton represented by the general formula (1). it can. Although there is no restriction | limiting in the manufacturing method, It can obtain by the well-known method of making epichlorohydrin react with a bisphenol F type epoxy resin and a phenol novolak type epoxy resin. Examples of the epoxy resin containing the bisphenol F skeleton and the phenol novolak skeleton represented by the general formula (1) include NER series manufactured by Nippon Kayaku Co., Ltd., YDPF series manufactured by Tohto Kasei Co., Ltd., and the like.

  The reactive elastomer component (b) is preferably a low molecular weight polymer component having a carboxyl group at both molecular ends and containing a butadiene skeleton, and specific examples thereof include polybutadiene acrylonitrile dicarboxylic acid and polybutadiene dicarboxylic acid. Moreover, the average molecular weight is preferably 500 to 5000, and more preferably 1000 to 3000. When the average molecular weight is less than 500, sufficient folding resistance cannot be imparted to the photosensitive resin composition, and when it exceeds 5000, reliability such as resistance to electric corrosion and PCT is lowered. Other reactive elastomer components include low molecular weight polymer components that contain silicon in the molecule, but in COF mounting, the silicon component decomposes due to the thermal history during the component mounting process, and the sealing material adheres by outgassing. Use is not preferred as it can reduce force. Examples of the polybutadiene acrylonitrile dicarboxylic acid include Hiker CTBN series manufactured by Ube Industries, Ltd., and examples of the polybutadiene dicarboxylic acid include C-1000 manufactured by Nippon Soda Co., Ltd.

  Examples of the unsaturated monocarboxylic acid (c) include acrylic acid, dimer of acrylic acid, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, α-cyanocinnamic acid and the like. It is done. Moreover, the half ester compound which is a reaction product of a hydroxyl-containing acrylate and a saturated or unsaturated dibasic acid anhydride is mentioned. The half-ester compound can be obtained by reacting a hydroxyl group-containing acrylate or unsaturated group-containing monoglycidyl ether with a saturated or unsaturated dibasic acid anhydride in an equimolar ratio. These unsaturated group-containing monocarboxylic acids (c) can be used alone or in combination of two or more.

  Examples of the hydroxyl group-containing acrylate and unsaturated group-containing monoglycidyl ether used in the synthesis of the half ester compound as an example of the unsaturated group-containing monocarboxylic acid (c) include hydroxyethyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl acrylate. , Hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol pentaacrylate , Pentaerythritol pentamethacrylate , Glycidyl acrylate and glycidyl methacrylate and the like. Examples of the saturated or unsaturated dibasic acid anhydride used in the synthesis of the half ester compound include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, and ethyltetrahydrophthalic anhydride. Examples thereof include acid, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride and the like.

  In the reaction of the epoxy resin (a) with the reactive elastomer component (b) and the unsaturated group-containing monocarboxylic acid (c) in the present invention, the reactive elastomer component with respect to 1 equivalent of the epoxy group of the epoxy resin (a) It is preferable to make it react in the ratio from which the sum total of (b) and unsaturated group containing monocarboxylic acid (c) will be 0.8-1.20 equivalent, More preferably, it is 0.9-1.10 equivalent.

  The reactive elastomer component (b) is preferably 0.005 to 0.1 equivalent, more preferably 0.01 to 0.05 equivalent, relative to the unsaturated group-containing monocarboxylic acid (c). . If the reactive elastomer component (b) is less than 0.005 equivalent to the unsaturated group-containing monocarboxylic acid (c), sufficient flexibility cannot be obtained, and folding resistance is lowered. On the other hand, when the reactive elastomer component (b) exceeds 0.1 equivalent with respect to the unsaturated group-containing monocarboxylic acid (c), the photocurability of the resin is lowered, and the photosensitive properties, electric corrosion resistance, and PCT resistance are reduced. descend.

  The epoxy resin (a) and the reactive elastomer component (b) the unsaturated group-containing monocarboxylic acid (c) are dissolved and reacted in an organic solvent. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, Aromatic hydrocarbons such as toluene, xylene, tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol mono Glycol ethers such as ethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, aliphatic hydrocarbons such as octane and decane, petroleum ether, petroleum naphtha , Hydrogenated petroleum naphtha, petroleum solvents such as solvent naphtha. Furthermore, it is preferable to use a catalyst to accelerate the reaction. Examples of the catalyst used include triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, and triphenylphosphine. The usage-amount of a catalyst is 0.1-10 weight part with respect to a total of 100 weight part of an epoxy resin (a), a reactive elastomer component (b), and an unsaturated group containing monocarboxylic acid (c). For the purpose of preventing polymerization during the reaction, a polymerization inhibitor is preferably used. Examples of the polymerization inhibitor include hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol and the like. The amount used is an epoxy resin (a), a reactive elastomer component (b), and an unsaturated group-containing monocarboxylic acid. It is 0.01-1 weight part with respect to a total of 100 weight part of an acid (c). The reaction temperature is preferably 60 to 150 ° C, more preferably 80 to 120 ° C.

  In the present invention, the acid-modified vinyl group-containing epoxy resin (A), which is a photocurable resin, reacts the above-mentioned epoxy resin (a) with the reactive elastomer component (b) unsaturated group-containing monocarboxylic acid (c). It is obtained by reacting the reaction product (A ′) obtained in this manner with a saturated or unsaturated group-containing polybasic acid anhydride (d). Examples of the saturated or unsaturated group-containing polybasic acid anhydride (d) include, for example, succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydroanhydride Examples thereof include phthalic acid, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride and the like, and these can be used alone or in combination of two or more.

  In the reaction of the reaction product (A ′) with the saturated or unsaturated group-containing polybasic acid anhydride (d), a saturated or unsaturated group-containing polyhydric acid is used with respect to 1 equivalent of the hydroxyl group in the reaction product (A ′). By reacting the basic acid anhydride (d) in an amount of 0.1 to 1.0 equivalent, the acid value of the acid-modified vinyl group-containing epoxy resin (A) can be adjusted. The acid value of the acid-modified vinyl group-containing epoxy resin (A) is preferably 30 to 150 mgKOH / g, and more preferably 50 to 120 mgKOH / g. When the acid value is less than 30 mgKOH / g, the solubility of the photocurable resin composition in a dilute alkali solution is lowered, and when it exceeds 150 mgKOH / g, the electric properties of the cured film tend to be lowered. The reaction temperature between the reaction product (A ′) and the saturated or unsaturated group-containing polybasic acid anhydride (d) is preferably 60 to 120 ° C., more preferably 80 to 100 ° C.

  As the photopolymerization initiator (B) used in the present invention, a type that generates radicals when irradiated with ultraviolet rays from a general-purpose exposure machine for producing printed wiring boards can be used. For example, benzoins such as benzoin, benzoin methyl ether, benzoin isopropyl ether, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxy Acetophenones such as cyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2,2-diethoxyacetophenone, N, N-dimethylaminoacetophenone, 2 -Anthraquinones such as methyl anthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone, 2,4-dimethylthioki Thioxanthones such as nitrophenone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal, benzophenone, methylbenzophenone, 4,4′-dichlorobenzophenone, 4,4'-bis (diethylamino) benzophenone, Michler's ketone, benzophenones such as 4-benzoyl-4'-methyldiphenyl sulfide, acridi such as 9-phenylacridine, 1,7-bis (9,9'-acridinyl) heptane Derivatives, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and the like. These can be used alone or in combination of two or more.

  The blending amount of the photopolymerization initiator (B) is preferably 0.5 to 20 parts by weight, more preferably 1 to 10% by weight with respect to 100 parts by weight of the photosensitive resin composition. When the blending amount is less than 0.5 parts by weight, the amount of radicals generated by ultraviolet rays is insufficient, so that the photocurability of the photosensitive resin composition becomes insufficient, and a problem arises in the developer resistance of the exposed portion. On the other hand, if the blending amount exceeds 20 parts by weight, light is not sufficiently transmitted to the lower part of the photosensitive resin layer, and problems such as undercut occur.

  The epoxy resin (C) used in the present invention is used for the purpose of imparting insulating properties and heat resistance to the photosensitive resin composition. Although there is no restriction | limiting in particular in the kind, For example, general purpose well-known epoxy resins, such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a novolak type epoxy resin, can be used. Examples of such epoxy resins include Epicoats 815, 828, 834, 1001, and 1009 manufactured by JER Co., Ltd. as bisphenol A type epoxy resins, YDPF series manufactured by Tohto Kasei Co., Ltd., and Nippon Steel Chemical Co., Ltd. as bisphenol F type epoxy resins. Company-made YSLV-80XY, novolac type epoxy resin includes DEN-438 manufactured by Dainippon Ink and Chemicals, ESCN-195 manufactured by Sumitomo Chemical Co., Ltd., KRM-2650 manufactured by Asahi Denka Kogyo Co., Ltd. Can do.

  In addition, for example, biphenyl type epoxy resin (manufactured by JER Corporation: YX4000), dicyclo type epoxy resin (manufactured by Dainippon Ink and Chemicals, Inc .: Epicron HP7200), glycidylamine type epoxy resin (manufactured by Dainippon Ink and Chemicals, Inc .: Epicron 430, Sumitomo Chemical Co., Ltd .: ELM100, 120, 434), Glycidyl ester type epoxy resin (Nagase Kogyo Co., Ltd .: Denacol EX-721), Naphthalene type epoxy resin (Dainippon Kagaku Kogyo Co., Ltd .: Epicron HP-) 4032, manufactured by Nippon Kayaku Co., Ltd .: NC-7000), bisphenol S type epoxy resin (manufactured by Toto Kasei Co., Ltd .: EBPS-300, manufactured by Dainippon Ink & Chemicals, Inc .: EXA-4004), and the like. These epoxy resins can be used alone or in combination of two or more. Moreover, the compounding quantity is preferable 1-70 weight part with respect to 100 weight part of solid content of the photosensitive resin composition, Furthermore, 20-50 weight part is preferable. If the amount is less than 1 part by weight, the heat resistance, chemical resistance and insulation reliability of the resist coating film tend to be lowered. If the amount exceeds 70 parts by weight, the photocurability of the photosensitive resin composition is lowered and the developer resistance is increased. In addition, the folding resistance tends to decrease.

  The epoxy group-containing polyamideimide resin (D) used in the present invention is produced by reacting an epoxy resin (f) with an acid-terminated polyamideimide resin (e) that can be synthesized from an organic diisocyanate or diamine by a condensation reaction. In synthesizing the acid-terminated polyamideimide (e), a polyvalent carboxylic acid component such as dicarboxylic acid, tricarboxylic acid, or tetracarboxylic dianhydride can be used as necessary.

  Examples of the polyvalent carboxylic acid component used for the production of the acid-terminated polyamideimide resin (e) include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, decanedioic acid, dodecanedioic acid, and dimer acid. Aromatic dicarboxylic acids such as aromatic dicarboxylic acids such as aromatic dicarboxylic acids, isophthalic acid, terephthalic acid, phthalic acid, naphthalene dicarboxylic acid, oxydibenzoic acid, trimellitic acid, pyromellitic acid, diphenylsulfone tetracarboxylic dianhydride Etc. These can be used alone or in combination of two or more.

  The organic diisocyanate used in the production of the polyamideimide resin (e) used in the present invention is 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthalene. Aromatic isocyanates such as diisocyanate, 3,3-dimethyl-4,4-diphenylmethane diisocyanate, P-phenylene diisocyanate, m-xylene diisocyanate, m-tetramethylxylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexa Methylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, transcyclohexane-1,4-diisocyanate, hydrogenated m-xylene diisocyanate Over DOO, and aliphatic isocyanates such as lysine diisocyanate. Of these, aromatic diisocyanates are preferable from the viewpoint of heat resistance, and 4,4'-diphenylmethane diisocyanate and tolylene diisocyanate are particularly preferable. These may be used singly, but since crystallinity increases, it is preferable to use two or more in combination.

  Diamine can also be used in place of the diisocyanate. Examples of the diamine include phenylenediamine, diaminodiphenylpropane, diaminodiphenylmethane, benzidine, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, diaminodiphenyl ether, and the like. 2,2-bis (3-aminophenoxyphenyl) propane, 2,2-bis (4-aminophenoxyphenyl) propane, 3,3-bis (3-aminophenoxyphenyl) sulfone to improve solubility in organic solvents 4,4-bis (3-aminophenoxyphenyl) sulfone, 3,8-bis (4-aminophenoxyphenyl) sulfone, 4,4-bis (4-aminophenoxyphenyl) sulfone, 2,2-bis (3 -Aminophenoxyphenyl) hexafluoropropane, 2,2-bis (4-aminophenoxyphenyl) hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene 4,4- (p-phenylenediisopropylidene) bisaniline, 4,4- (m-fu It is preferable to use a two-range isopropylidene) diamines such bisaniline. These diamines and diisocyanates may be used alone or in combination of two or more. However, if diamine and diisocyanate are used at the same time, they react to form a urea bond with poor heat resistance, which is not preferable.

  As the polyamideimide resin (e) used in the present invention, a carboxyl group-terminated polyamideimide resin having at least one polymer unit selected from a polyalkylene oxide unit and a polycarbonate unit in the molecular structure is preferably used. The polyalkylene oxide unit and the polycarbonate unit introduced into the molecular structure of the polyamideimide resin are usually a polyalkylene glycol or a dicarboxylic acid such as a carboxylate at both ends of a polycarbonate diol as a polyvalent carboxylic acid component, Reaction is introduced into the polyamideimide skeleton. Examples of the polyalkylene glycol include a reaction product of polytetramethylene ether glycol, polypropylene glycol, polyethylene glycol, bisphenol A or hydrogenated bisphenol A and these polyalkylene glycols, and two or more of these alkylene oxide units per molecule. May be present. Examples of the polycarbonate diol include linear aliphatic polycarbonate diols, such as Plaxel CD series (manufactured by Daicel Chemical Industries), NIPPOLAN 980, 981 (manufactured by Nippon Polyurethane Industry), and the like. About the chemical structure of polycarbonate diol, what is represented, for example by following formula (2) is mentioned.

（式中、Ｒは２価アルコール残基を表し、ｎは１〜１０の整数である。）

(In the formula, R represents a dihydric alcohol residue, and n is an integer of 1 to 10.)

  In particular, the dihydric alcohol residue has 1 to 100 carbon atoms, such as 1,5-pentanediol residue, methylpentanediol residue, cyclohexanone dimethanol residue, 1,6-hexanediol residue, 1 , 9-nonanediol residue, 2-methyl-1,8-octanediol residue, and liquid at room temperature (25 ° C.) are preferably used.

  In order to make polyalkylene glycol and polycarbonate diol into carboxylic acids at both terminals, the same polyvalent carboxylic acid as that of the polyvalent carboxylic acid component, preferably dicarboxylic acid, may be reacted with polyalkylene glycol and polycarbonate diol. The total content of the polyalkylene oxide unit or the polycarbonate unit is preferably 10% by weight or more in the polyamideimide resin (e) from the viewpoint of adhesiveness and 70% by weight or less from the viewpoint of heat resistance.

  In the production of the carboxyl group-terminated polyamideimide resin (e), the polyvalent carboxylic acid component is 1 or more, preferably 1 to 3, more preferably 1.1 to 1. in a molar ratio with respect to the total of the diisocyanate component and the diamine component. 3. Mix and react. The above reaction uses lactones such as γ-butyrolactone, amide solvents such as N-methylpyrrolidone (NMP) and dimethylformamide (DMF), sulfones such as tetramethylene sulfone, and ethers such as diethylene glycol dimethyl ether. And react at 50 to 250 ° C. Considering the reaction yield, solubility, and volatility in the subsequent step, it is preferable to use γ-butyrolactone as the main component of the solvent.

  The epoxy resin (f) to be reacted with the acid-terminated polyamideimide resin (e) is bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, naphthalene type Epoxy resin and modified product thereof, Bixylenyl diglycidyl ether, YDC1312 (trade name, manufactured by Tohto Kasei Co., Ltd.), Techmore VG3101 (trade name, manufactured by Mitsui Petrochemical Co., Ltd.), TMH574 (trade name, manufactured by Sumitomo Chemical Co., Ltd.), Epicote 1031S (oil) Aromatic epoxy resins such as Kabushiki Kaisha's trade name), aliphatic epoxy resins such as neopentyl glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and tetrahydrophthalic acid diglycidyl ester, trig And heterocyclic epoxy compounds such as triglycidyl isocyanurate. Among these, a bifunctional epoxy resin is preferable from the viewpoint of reaction control. These may be used alone or in combination of two or more. These epoxy resins are reacted with a carboxyl group-terminated polyamideimide resin and an epoxy group / carboxyl molar ratio greater than 1. When the molar ratio of epoxy group / carboxyl group is 1 or less, a terminal epoxy resin cannot be obtained. The epoxy equivalent of the modified epoxy resin thus obtained is preferably 500 to 40,000. If the molecular weight is less than 500, the molecular weight is low and the adhesiveness is lowered.

  Although the hydroxyl group remains in the epoxy group-containing polyamideimide resin (D) used in the present invention, in consideration of the photosensitive characteristics and the like, further, isocyanatoethyl (meth) acrylate, tolylene diisocyanate or isophorone diisocyanate and one molecule. An unsaturated bond may be introduced via a urethane bond by reacting an equimolar reaction product with (meth) acrylate having one or more hydroxyl groups therein, for example, hydroxyethyl (meth) acrylate.

  The blending amount of the epoxy group-containing polyamideimide resin (D) is preferably 5 to 30 parts by weight, more preferably 10 to 25 parts by weight with respect to 100 parts by weight of the solid content of the photosensitive resin composition. If the amount is less than 5 parts by weight, sufficient folding resistance cannot be imparted to the photosensitive resin composition. On the other hand, if the blending amount exceeds 25 parts by weight, a problem occurs in developability.

  For the purpose of improving the developability of the photosensitive resin composition, a part of the epoxy group-containing polyamideimide is reacted with the unsaturated monocarboxylic acid component (c) to the epoxy group of the epoxy group-containing polyamideimide (D). It can also be replaced with an acid-modified polyamideimide (D ′), which is an addition reaction product obtained by adding a saturated or unsaturated polybasic acid anhydride (d) to the esterified product obtained in advance. Examples of the unsaturated monocarboxylic acid component (c) and saturated or unsaturated polybasic acid anhydride (d) used in the addition reaction of the acid-modified polyamideimide (D ′) include an epoxy resin (a) and an acid-modified vinyl. Various compounds that can be used in obtaining the epoxy resin (A) can be used. The blending amount is preferably 0 to 60 parts by weight, more preferably 0 to 35 parts by weight with respect to 100 parts by weight of the solid content of the photosensitive resin composition. If the blending amount exceeds 60 parts by weight, a problem occurs in developability.

  In the photosensitive resin composition of the present invention, a photopolymerizable monomer can be used for the purpose of improving photosensitivity and developer resistance as required. Examples of the photopolymerizable monomer include 2-hydroxyethyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, N, N-dimethyl ( (Meth) acrylate, N-methylol (meth) acrylamide, polyethylene glycol, polypropylene glycol, polyethylene glycol or propylene glycol of bisphenol A, mono- or polyfunctional (meth) acrylates of tris (2-hydroxyethyl) isocyanuric acid, triglycidyl Photopolymerizable monomers such as (meth) acrylates of glycidyl ether such as isocyanurate and diallyl phthalate can be used. These can be used alone or in combination of two or more. As for the compounding quantity of said photopolymerizable monomer, 0.5-30 weight part is preferable with respect to 100 weight part of photosensitive resin compositions. If the blending amount is less than 0.5 parts by weight, the exposure sensitivity is low, so that it is necessary to spend a lot of time in the exposure process, and the productivity of the substrate tends to decrease. On the other hand, if the blending amount exceeds 30 parts by weight, flexibility and heat resistance tend to decrease.

  In the photosensitive resin composition of this invention, an inorganic filler can be used for the purpose of improving the mechanical strength of a coating film as needed. Examples of the inorganic filler that can be used include barium sulfate, silicon oxide, magnesium oxide, calcium carbonate, zirconium silicate, zirconium oxide, calcium silicate, talc, clay, silica, bentonite, and kaolin zirconium silicate. These can be used alone or in combination of two or more.

  In the photosensitive resin composition of the present invention, as required, known colorants such as phthalocyanine blue, phthalocyanine green, iodin green, bisazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, Various known and commonly used additives such as polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, silicone-based, fluorine-based, vinyl resin-based antifoaming agents, silane coupling agents, adhesion imparting agents, etc. Can be used.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
Production Example of Acid-Modified Vinyl Epoxy Resin (A-1) (A-1) Production Example NER-7403 (epoxy) which is an epoxy resin represented by the general formula (1) in a flask equipped with a stirrer, a reflux condenser and a thermometer. Equivalent 291 g / eq) (manufactured by Toto Kasei Co., Ltd .: trade name) 200 parts by weight, polybutadiene acrylonitrile dicarboxylic acid CTBN 1300 × 13 (average molecular weight: 3000 (average molecular weight per equivalent of carboxylic acid: 1500)), 25 parts by weight 110 parts by weight of butyl diglycol acetate was charged and heated and stirred under a nitrogen atmosphere at 100 ° C. to dissolve the mixture. Next, after cooling the solution to 70 ° C. and switching to an oxygen atmosphere, 45 parts by weight of acrylic acid, 0.2 part by weight of methylhydroquinone, 1.2 parts by weight of triphenylphosphine, and 36 parts by weight of butyl diglycol acetate are charged. The mixture was heated to 100 ° C. and reacted until the acid value was 2 (KOH mg / g) or less. Next, the resulting solution was cooled to 70 ° C., charged with 21 parts by weight of succinic anhydride, 33 parts by weight of tetrahydrophthalic anhydride, and 30 parts by weight of butyl diglycol acetate, reacted at 80 ° C. for a predetermined time, and acid value 51 ( KOH mg / g), polybutadiene acrylonitrile dicarboxylic acid (CTBN) addition type acid-modified vinyl epoxy resin (A-1) having a solid content of 65% by weight was obtained.

Production Example of Acid-Modified Vinyl Epoxy Resin (A-2) (A-2) Production Example A polybutadiene acrylonitrile dicarboxylic acid (CTBN 1300 × 13) in Production Example A-1 was converted to polybutadiene dicarboxylic acid (C-1000) (average molecular weight: 2000) (The average molecular weight per equivalent of carboxylic acid: 1000) The same production method was used except that the polybutene dicarboxylic acid (C-1000) addition type acid-modified vinyl epoxy resin (A-2) was obtained. The acid value was 53 (KOHmg / g), and the solid content was 64% by weight.

Production example (D-1) of epoxy group-containing polyamideimide resin (D-1) Production example (D-1) PEG # 1000 diamine (average), which is a polyethylene glycol in which both ends are amine-modified in a flask equipped with a stirrer, reflux condenser and thermometer (Molecular weight: 1146) (Nippon Yushi Co., Ltd .: trade name) 173 parts by weight and 57 parts by weight of trimellitic acid were charged, and the mixture was dissolved by heating and stirring under a nitrogen atmosphere at 120 ° C. Next, an appropriate amount of toluene was added to remove water in the flask. After removing water, a toluene removal reaction was performed under a nitrogen atmosphere at 200 ° C. to obtain polyimide (i). Next, the solution was cooled to room temperature (25 ° C.), 0.45 parts by weight of 4,4-diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI) (trade name: manufactured by Nippon Polyurethane Industry Co., Ltd.) 1 .26 parts by weight and 28 parts by weight of γ-butyrolactone were charged, and kept at 200 ° C. for 4 hours to obtain polyamideimide. Next, the solution was cooled to 120 ° C., and 6.4 parts by weight of YDF-2001 (epoxy equivalent 471 g / eq) (product name of Toto Kasei Co., Ltd.), which is a bisphenol F type epoxy resin, and 9 parts by weight of γ-butyrolactone were added. Charged and kept warm for 6 hours. The resulting epoxy group-containing polyamideimide resin had an acid value of 1.1 (KOHmg / g) and a solid content of 45% by weight.

Production example of epoxy group-containing polyamideimide resin (D-2) (D-2 production example)
A flask equipped with a stirrer, reflux condenser and thermometer, PEG # 1000 diamine (average molecular weight: 1146) (Nippon Yushi Co., Ltd .: trade name), a polyethylene glycol whose both ends are amine-modified, 173 parts by weight, trimellitic acid 57 A part by weight was charged and heated and stirred under a nitrogen atmosphere at 120 ° C. to dissolve the mixture. Next, an appropriate amount of toluene was added to remove water in the flask. After removing water, a toluene removal reaction was performed under a nitrogen atmosphere at 200 ° C. to obtain polyimide (i).

  6. A flask equipped with a stirrer, a reflux condenser, and a thermometer. Plaxel CD220 (average molecular weight: 2000) which is a polycarbonate diol (Daicel Chemical Industries, Ltd .: trade name), 149 parts by weight, 4,4-diphenylmethane diisocyanate (MDI) 5 parts by weight, 20.9 parts by weight of tolylene diisocyanate (TDI) (manufactured by Nippon Polyurethane Industry Co., Ltd .: trade name) and 118 parts by weight of γ-butyrolactone were added, and kept at 150 ° C. for 4 hours under a nitrogen atmosphere. (Ii) was obtained.

  Next, a flask equipped with a stirrer, a reflux condenser and a thermometer was charged with 52 parts by weight of polyimide (i), L-20, which is a linear fatty acid having 20 carbon atoms, 176 parts by weight of γ-butyrolactone, and nitrogen. The mixture was dissolved by heating and stirring under conditions of 100 ° C. in an atmosphere. Next, the resulting solution was cooled to 70 ° C., charged with 276 parts by weight of polycarbonate (ii) and 176 parts by weight of γ-butyrolactone, and kept at 200 ° C. for 3 hours in a nitrogen atmosphere to obtain polyamideimide.

  Next, the solution was cooled to 120 ° C., and 61 parts by weight of YDF-2001 (epoxy equivalent 471 g / eq) (manufactured by Tohto Kasei Co., Ltd.), which is a bisphenol F type epoxy resin, was charged and kept warm for 6 hours. The resulting epoxy group-containing polyamideimide resin had an acid value of 0.3 (KOHmg / g) and a solid content of 46% by weight.

Production Example of Acid-Modified Polyamideimide Resin (D′-1) (D′-1 Production Example)
(D-1) 371 parts by weight of an epoxy group-containing polyamideimide (D-1) produced based on the production example, 3.2 parts by weight of methacrylic acid, 0.02 parts by weight of methylhydroquinone, 0.2 parts by weight of triphenylphosphine Was placed in a flask equipped with a stirrer, a reflux condenser and a thermometer, and kept under an oxygen atmosphere at 120 ° C. for 4 hours to react until the acid value was in the range of 3 to 5 (KOH mg / g). Next, the resulting solution was cooled to 70 ° C., charged with 43 parts by weight of tetrahydrophthalic anhydride, reacted at 80 ° C. for a predetermined time, and acid-modified polyamideimide having an acid value of 47 (KOHmg / g) and a solid content of 46% by weight. Resin (D′-1) was obtained.

Production example of acid-modified polyamideimide resin (D′-2) (D′-2 production example)
(D-2) 382 parts by weight of an epoxy group-containing polyamideimide (D-2) prepared based on the production example, 4.3 parts by weight of acrylic acid, 0.05 part by weight of methylhydroquinone, 0.3 part by weight of triphenylphosphine Was placed in a flask equipped with a stirrer, a reflux condenser and a thermometer, and kept under an oxygen atmosphere at 120 ° C. for 4 hours to react until the acid value was in the range of 3 to 5 (KOH mg / g). Next, the resulting solution was cooled to 70 ° C., charged with 39 parts by weight of tetrahydrophthalic anhydride, reacted at 80 ° C. for a predetermined time, and acid-modified polyamideimide having an acid value of 41 (KOHmg / g) and a solid content of 43% by weight. Resin (D′-2) was obtained.

(Examples 1-4)
Using the acid-modified vinyl epoxy resin (A), epoxy group-containing polyamide-imide resin (D), and acid-modified polyamide-imide resin (D ′) obtained as described above, the formulations (compositions) shown in Tables 1 and 2 below. Accordingly, the resin compositions of main agents 1 to 4 (4 types) and curing agents 1 to 2 (2 types) were separately kneaded and produced using a three-roll mill. The obtained main agent and curing agent were combined in Examples 1 to 4 shown in Table 3 below, and mixed at a weight ratio of 70:30 to obtain a photosensitive resin composition (resist ink composition).

(Comparative Examples 1-3)
The case where the cresol novolac type epoxy acrylate (A-3) produced by the method shown below is used and the case where the blending amount of the epoxy group-containing polyamideimide resin (D-1) is adjusted are compared with the examples. It was. According to the formulation (composition) shown in Tables 1 and 2 below, resin compositions of main agents 5, 6 (2 types) and curing agents 3, 4 (2 types) were separately kneaded and prepared using a three-roll mill. The obtained main agent and curing agent were combined in Comparative Examples 1 to 3 shown in Table 3 below, and mixed at a weight ratio of 70:30 to obtain a photosensitive resin composition (resist ink composition).

Production Example of Acid-Modified Vinyl Epoxy Resin (A-3) (A-3) Production Example DEN-438 (epoxy equivalent 200 g / eq), which is a cresol novolac type epoxy resin, in a flask equipped with a stirrer, reflux condenser and thermometer. ) (Dainippon Ink Co., Ltd .: trade name) 200 parts by weight, polybutadiene acrylonitrile dicarboxylic acid CTBN 1300 × 13 (average molecular weight: 3000 (average molecular weight per equivalent of carboxylic acid: 1500)), 23 parts by weight butyl diglycol acetate 148 parts by weight were charged, and the mixture was heated and stirred under a nitrogen atmosphere at 100 ° C. to dissolve the mixture. Next, after cooling the solution to 70 ° C. and switching to an oxygen atmosphere, 52 parts by weight of acrylic acid, 0.15 part by weight of methylhydroquinone and 1 part by weight of triphenylphosphine were added and heated to 100 ° C. The reaction was continued until 2 (KOHmg / g) or less. Next, the obtained solution was cooled to 70 ° C., charged with 15 parts by weight of succinic anhydride, 24 parts by weight of tetrahydrophthalic anhydride, and 29 parts by weight of butyl diglycol acetate, reacted at 80 ° C. for a predetermined time, and acid value 54 ( KOH mg / g), polybutadiene acrylonitrile dicarboxylic acid (CTBN) addition type acid-modified vinyl epoxy resin (A-3) having a solid content of 65% by weight was obtained.

＊１：チバガイギー株式会社製、＊２：日本化薬株式会社製、＊３：山陽色素株式会社製

* 1: Ciba Geigy Co., Ltd. * 2: Nippon Kayaku Co., Ltd. * 3: Sanyo Dye Co., Ltd.

＊４：新日鉄化学株式会社製、＊５：日本化薬株式会社製

* 4: Nippon Steel Chemical Co., Ltd. * 5: Nippon Kayaku Co., Ltd.

The characteristics of the photosensitive resin compositions (resist ink compositions) of Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated by the following items.
(Photosensitive characteristics)
Samples for coating film appearance test evaluation were prepared and evaluated by the following methods.
1) A photosensitive resin composition is applied onto a polyimide film substrate (Espanex: manufactured by Nippon Steel Chemical Co., Ltd .: trade name) with a thickness of 25 μm so that the film thickness after drying is 10 to 15 μm and dried (80 ° C / 15 minutes).
2) Ultraviolet rays are irradiated with an exposure amount of 500 to 1000 mJ / cm ² through a photomask in which a circular shielding portion having a diameter of 100 μm is provided at a position where a resist pattern is to be formed.
3) Next, by developing for 1 to 3 minutes with a predetermined alkaline developer kept at 30 ± 5 ° C., the unexposed portion is dissolved and removed to form a resist pattern (Φ100 μm via).
4) A thermosetting treatment is performed at 150 ° C. for 60 minutes.

(Folding resistance)
The film thickness after drying the photosensitive resin composition on a 25 μm thick polyimide film substrate (Espanex: manufactured by Nippon Steel Chemical Co., Ltd .: trade name) on which a conductor circuit of L / S = 50/50 μm is formed is 10 It is applied and dried (80 ° C./15 minutes) so as to be ˜15 μm. Hereinafter, the same exposure, development, and thermosetting treatment as the photosensitive characteristics were performed to prepare samples. The folding resistance was evaluated by 135 ° facing bending according to JIS P 8115, and the number of bendings until the circuit was disconnected was evaluated.

(Warpage characteristics)
The photosensitive resin composition is applied on a polyimide film substrate (Espanex: manufactured by Nippon Steel Chemical Co., Ltd .: trade name) having a thickness of 25 μm and a size of 50 mm × 50 mm so that the film thickness after drying is 10 to 15 μm. Dry (80 ° C./15 minutes). Hereinafter, the same exposure, development, and thermosetting treatment as the photosensitive characteristics were performed to prepare samples. The warpage was evaluated at n = 5, and the value was expressed as an average value of n = 5.

(PCT resistance)
Evaluation was performed using the same sample as the warpage characteristic evaluation sample. The evaluation was performed by evaluating the appearance of the resist coating film after being left for 96 hours under the condition of 121 ° C./100%. A sample in which no abnormality such as swelling and peeling was observed in the coating film was marked with “◯”, and a sample in which abnormality such as swelling and peeling was found was marked with “X”.

(Electric corrosion resistance)
Film after drying photosensitive resin composition on 25 μm-thick polyimide film substrate (Espanex: manufactured by Nippon Steel Chemical Co., Ltd .: trade name) on which a comb-shaped conductor circuit of L / S = 50/50 μm is formed It is applied and dried (80 ° C./15 minutes) so that the thickness becomes 10 to 15 μm. Hereinafter, the same exposure, development, and thermosetting treatment as the photosensitive characteristics were performed to prepare samples. In the evaluation, a voltage of 100 V was applied for 1000 hours under the condition of 85 ° C./85%, and the change in the insulation resistance value between the circuits was examined. When the insulation resistance value between the circuits was 8th order or less before reaching 1000 hours, it was determined that the insulation was defective (insufficient electric corrosion resistance: x).

(Tensile modulus, elongation)
The photosensitive resin composition is applied onto a PET film having a thickness of 50 μm and dried (80 ° C./15 minutes) so that the film thickness after drying becomes 40 to 60 μm. Thereafter, exposure, development, and thermosetting treatment similar to the photosensitive characteristics were performed, and the PET film was peeled off to obtain a film cured product (tensile elongation, elastic modulus evaluation sample). The tensile elongation and the elastic modulus were evaluated by n = 5, and the value was expressed as an average value of n = 5.
A summary of the above evaluation results is shown in Table 4.

Conventional photosensitive resin plastics for photosensitive solder resists have been difficult to satisfy the bending resistance and warpage characteristics required for a flexible wiring board for COF mounting. The esterified product obtained by reacting the reactive elastomer component (b) and the unsaturated monocarboxylic acid component (c) with the epoxy resin (a) represented by 1) is further saturated or unsaturated polybasic acid anhydride (d). Using the acid-modified vinyl epoxy resin (A), photoinitiator (B), epoxy resin (C), and epoxy group-containing polyamide-imide resin (D), which are addition reaction products obtained by adding bisphenol, are shown in Table 4. Thus, a photosensitive resin composition excellent in folding resistance and warpage characteristics could be obtained without impairing reliability such as electric corrosion resistance and PCT resistance.

Claims (7)

The esterified product obtained by reacting the reactive elastomer component (b) and the unsaturated monocarboxylic acid component (c) with the epoxy resin (a) represented by the general formula (1) is further saturated or unsaturated polybasic acid anhydride. Photosensitive resin comprising acid-modified vinyl epoxy resin (A), photoinitiator (B), epoxy resin (C), and epoxy group-containing polyamideimide resin (D) as an addition reaction product to which (d) is added Composition.

(R is a hydrogen atom or a substituent represented by the general formula (1a))

  The photosensitive elastomer according to claim 1, wherein the reactive elastomer component (b) is a low molecular weight polymer component having a carboxyl group at both molecular ends and containing a butadiene skeleton and having an average molecular weight of 500 to 5,000. Resin composition.   The epoxy group-containing polyamideimide resin (D) comprises a carboxyl group-terminated polyamideimide resin (e) having at least one polymer unit selected from a polyalkylene oxide unit and a polycarbonate unit in the molecular structure, and an epoxy resin (f). The photosensitive resin composition according to claim 1, which is an epoxy group-containing polyamideimide resin obtained by reacting with an epoxy group / carboxyl group molar ratio of greater than 1.   The photosensitive group according to any one of claims 1 to 3, wherein the epoxy group-containing polyamideimide (D) is 20 to 50 parts by weight with respect to 100 parts by weight of the solid content of the acid-modified vinyl epoxy resin (A). Resin composition.   The photosensitive resin composition according to any one of claims 1 to 4, which has a tensile modulus at ordinary temperature (25 ° C) of 1500 MPa or less and a tensile elongation of 10 to 30% when heat-cured. .   The photosensitive resin composition according to any one of claims 1 to 5 is laminated on a film substrate, and an exposed part is photocured by irradiating an ultraviolet ray onto an image, and an unexposed part is selectively removed by development. A method for producing a resist pattern. A method for producing a flexible wiring board, wherein a permanent mask is formed by the method for producing a resist pattern according to claim 6.