KR20160004942A - Photosensitive thermosetting resin composition, dry film and printed wiring board - Google Patents

Abstract

The present invention provides a photosensitive and thermosetting resin composition which has excellent flexibility and is suitable for a uniform formation process of an insulating film on a flexible printed wiring board, especially a bent part (curved part) and a mounting part (non-curved part). In addition, provided is a printed wiring board having the hardening product as a protective film such as, for example, a cover lay or a solder resist. According to the present invention, the photosensitive thermosetting resin composition comprises: (A) a polyamideimide resin obtained by making an imide compound obtained through reaction of at least one sort of diamine containing carboxylic group-containing diamine and an acid anhydride (a1) including tricarboxylic acid anhydride react with a reacting raw material containing a diisocyanate compound; (B) a photobase generator; and (C) a thermosetting component.

Description

TECHNICAL FIELD [0001] The present invention relates to a photosensitive thermosetting resin composition, a dry film, and a printed wiring board,

The present invention relates to a photosensitive thermosetting resin composition, a dry film and a printed wiring board useful as an insulating film of a flexible printed wiring board.

BACKGROUND ART [0002] In recent years, it has become necessary to make a circuit board small in size by making electronic devices small and thin by the spread of smart phones and tablet terminals. As a result, flexibles that can be folded and housed expand their use for wiring boards, and a flexible printed wiring board is required to have higher reliability than ever before.

On the other hand, as the insulating film for securing the insulation reliability of the flexible printed wiring board at present, a coverlay based on polyimide excellent in mechanical properties such as heat resistance and bending property is used for the bent portion (bent portion) 1 and 2), and a mixed process using a photosensitive resin composition which is excellent in electric insulation property, solder heat resistance, and the like and can be microfabricated is widely adopted in the mounting portion (non-curved portion).

That is, the coverlay based on polyimide is not suitable for fine wiring because it requires machining by die punching. Therefore, it is necessary to partially use an alkali development type photosensitive resin composition (solder resist) capable of being processed by photolithography in the chip mounting portion where fine wiring is required.

Japanese Patent Application Laid-Open No. 62-263692 Japanese Patent Application Laid-Open No. 63-110224

As described above, in the conventional manufacturing process of the flexible printed wiring board, a mixed process of a process of aligning a coverlay and a process of forming a solder resist has to be adopted, and therefore, there is a problem that cost and workability are inferior.

On the other hand, conventionally, it has been studied to apply an insulating film as a solder resist or an insulating film as a coverlay as a solder resist and a coverlay of a flexible printed wiring board. However, a material which satisfies both required performance has not yet been put to practical use. Particularly, in the flexible printed wiring board, durability against bending becomes most important. Therefore, it has been demanded to realize a material which is applicable as a solder resist and a coverlay of a flexible printed wiring board and has excellent durability against bending.

Accordingly, an object of the present invention is to provide a photosensitive thermosetting resin composition excellent in flexibility and suitable for a process for collectively forming an insulating film of a flexible printed wiring board, in particular, a bending part (bending part) and a mounting part (non-bending part) And to provide a printed wiring board having cargo as a protective film, for example, a coverlay or a solder resist.

As a result of intensive studies for solving the above problems, the present inventors have found that the above problems can be solved by a specific polyamide-imide resin, a photo-base generating agent and a resin composition containing a thermosetting component, It came to the following.

That is, the photosensitive thermosetting resin composition of the present invention comprises (A) an imide compound obtained by reacting an acid anhydride (a1) containing at least one kind of diamine containing a carboxyl group-containing diamine and a tricarboxylic acid anhydride, and a diisocyanate (B) a photoacid generators, and (C) a thermosetting component. The polyimide-imide resin is obtained by reacting a reaction raw material containing a compound.

In the present invention, it is preferable that the acid anhydride (a1) includes either or both of trimellitic acid anhydride and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. Further, it is preferable that the reaction raw material further comprises a tricarboxylic acid anhydride (a2). Further, it is preferable that the acid anhydride (a2) includes either or both of trimellitic anhydride and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. Further, it is preferable that the polyamide-imide resin (A) further has an aliphatic structure and an ether bond. In this case, the aliphatic structure of the (A) polyamideimide resin is suitably hexane or cyclohexane. In this case, it is preferable that the ether bond of the (A) polyamideimide resin is a polyether structure derived from a diamine having an ether bond, and the molecular weight of the diamine having the ether bond is 200 or more.

The photosensitive thermosetting resin composition of the present invention preferably further comprises (D) a polyimide resin having an imide ring and a phenolic hydroxyl group. In this case, it is preferable that the polyimide resin (D) further comprises a carboxyl group desirable. In the present invention, it is preferable that the (C) thermosetting component is a cyclic ether compound. The photosensitive thermosetting resin composition of the present invention can be suitably used for a flexible printed wiring board.

Further, the dry film of the present invention is characterized by having a resin layer containing the photosensitive thermosetting resin composition of the present invention. The printed wiring board of the present invention is characterized by comprising a cured product formed using the photosensitive thermosetting resin composition of the present invention or the dry film of the present invention.

According to the present invention, there is provided a photosensitive thermosetting resin composition excellent in flexibility and suitable for a process for collectively forming an insulating film of a flexible printed wiring board, in particular, a bending part (bending part) and a mounting part (non-bending part), and a printed circuit board Can be realized.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a process diagram schematically showing an example of a manufacturing method of a flexible printed wiring board according to the present invention. FIG.

Hereinafter, embodiments of the present invention will be described in detail.

The photosensitive thermosetting resin composition of the present invention is a photosensitive thermosetting resin composition comprising (A) an imide compound obtained by reacting an acid anhydride (a1) containing at least one diamine containing a carboxyl group-containing diamine with a tricarboxylic acid anhydride, and a diisocyanate compound (B) a photoacid generating agent, and (C) a thermosetting component.

In the photosensitive thermosetting resin composition of the present invention, the photobase generator is activated by light irradiation, and the resulting base is used as a catalyst to cause addition reaction of the thermosetting component with the polyamide-imide resin having a carboxyl group, Can be removed by the alkali solution, whereby fine processing by the alkali development becomes possible, and it is expected that a cured product excellent in reliability can be obtained. The photosensitive thermosetting resin composition of the present invention is excellent in flexibility and has good developability and resolution, and therefore is suitable for a resin insulating layer of a flexible printed wiring board, for example, a cover or a solder resist.

Hereinafter, each component constituting the photosensitive thermosetting resin composition of the present invention will be described in detail.

[(A) Polyamideimide resin]

The polyamideimide resin (A) used in the present invention is obtained by reacting an acid anhydride (a1) containing at least one diamine containing a carboxyl group-containing diamine with a tricarboxylic acid anhydride to obtain an imide, And then reacting the reaction material containing imide and diisocyanate compound again. As described later, it is preferable that the reaction raw material further contains a tricarboxylic acid anhydride (a2) in addition to the imide cargo and the diisocyanate compound.

(Diamine)

Examples of the carboxyl group-containing diamine include diaminobenzoic acids such as 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid and 3,4-diaminobenzoic acid, 3,5-bis (3-aminophenoxy) Aminophenoxybenzoic acids such as benzoic acid and 3,5-bis (4-aminophenoxy) benzoic acid, 3,3'-methylenebis (6-aminobenzoic acid), 3,3'- Dicarboxybiphenyl, 4,4'-diamino-3,3'-dicarboxybiphenyl, 4,4'-diamino-2,2'-dicarboxybiphenyl, 4,4'- , 2 ', 5,5'-tetracarboxybiphenyl and the like, carboxybiphenyl compounds such as 3,3'-diamino-4,4'-dicarboxy diphenylmethane, 3,3'-dicarboxy- Amino-3-carboxyphenyl] propane, 2,2-bis [3-amino-4-carboxyphenyl] propane, 2,2- -Amino-4-carboxyphenyl] hexafluoropropane, and 4,4'-diamino-2, 2 ', 5,5'-tetracarboxydiphenyl methane. 3,3'-diamino-4,4'-dicarboxy diphenyl ether, 4,4'-diamino-3,3'-dicarboxy diphenyl ether, 4,4'-diamino Carboxy diphenyl ether compounds such as 2,2'-dicarboxy diphenyl ether and 4,4'-diamino-2, 2 ', 5,5'-tetracarboxydiphenyl ether, and 3,3'-diamino 4,4'-dicarboxy diphenylsulfone, 4,4'-diamino-3,3'-dicarboxy diphenylsulfone, 4,4'-diamino-2,2'- Diphenyl sulfone compounds such as 4,4'-diamino-2,2 ', 5,5'-tetracarboxydiphenyl sulfone, and diphenyl sulfone compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl (Carboxyphenoxy) phenyl] sulfone such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone and the like And the like, and they can be used alone or in appropriate combination.

In the present invention, as the diamine, it is necessary to use a carboxyl group-containing diamine, but those having no carboxyl group may be used in combination. As other diamines that can be used in combination, aliphatic diamines and aromatic diamines in general use can be used alone or in appropriate combination. Specific examples of the other diamine include p-phenylenediamine (PPD), 1,3-diaminobenzene, 2,4-toluenediamine, 2,5-toluenediamine and 2,6- Benzene nucleus, diaminodiphenyl ethers such as one diamine, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether and 3,4'-diaminodiphenyl ether, and 4,4'- Diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis Diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetramethyl-4,4' Diaminodiphenylmethane, bis (4-aminophenyl) sulfide, 4,4'-diaminobenzanilide, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine , 2'-dimethylbenzidine (m-tolidine), 3,3'-dimethoxybenzidine, 2,2'-dimethoxybenzidine, 3,3'-diaminodiphenyl ether, 3,4'- Phenyl ether, 4,4'-diaminodiphe Ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3 , 4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzophenone, 3'-diamino-4,4'-dimethoxybenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2 , 2-bis (3-aminophenyl) propane, 2,2-bis (4-aminophenyl) propane, 2,2- Fluoropropane, 2,2-bis (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenyl sulfoxide, 3,4'- Diaminodiphenylsulfoxide, 4,4'-diaminodiphenylsulfoxide, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, and other diamines such as 1,3-bis (3-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4- Benzene, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, (3-aminophenoxy) -4-trifluoromethylbenzene, 3,3'-diamino-4- (4-phenyl) phenoxybenzophenone, 3,3 ' Benzophenone, 1,3-bis (3-aminophenylsulfide) benzene, 1,3-bis (4-aminophenylsulfide) benzene, Benzene, 1,3-bis (4-aminophenylsulfone) benzene, 1,4-bis (4-aminophenylsulfone) (Aminophenylsulfone) benzene, 1,3-bis [2- (4-aminophenyl) isopropyl] benzene, 1,4- Benzene nucleus such as [2- (4-aminophenyl) isopropyl] benzene, 3,3'-bis (3-aminophenoxy) biphenyl, 3,3'- Biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, bis (4-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] (3-aminophenoxy) phenyl] ether, bis [3- (3-aminophenoxy) phenyl] ketone, bis [3- Phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [3- , Bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) Bis (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, (4-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] ) Phenyl] methane, 2,2-bis [3- (3-aminophenoxy) phenyl] propane, 2,2- Bis [3- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- , 1,1,3,3,3-hexafluoropropane, 2,2-bis [3- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane , 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2- ) Phenyl] -1,1,1,3,3,3-hexafluoropropane; aromatic diamines such as 1, 2-diaminoethane, 1, 3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9- - aliphatic diamines such as diaminodecane, 1,11-diamino undecane, 1,12-diaminododecane and 1,2-diaminocyclohexane, Can.

Examples of the diamine having ether bond include polyoxyethylene diamine, polyoxyethylene diamine, polyoxypropylene diamine, and polyoxybutylene diamine. D-400, D-2000, D-4000, Jeffamine ED-600, ED-900, ED-2003, Jeffamine XTJ-542 and the like. The molecular weight of the diamine having an ether bond is preferably 200 or more, more preferably 200 to 3,000, and still more preferably 400 to 2,000.

Examples of the amino-modified silicone include BY16-205, FZ-3760, BY16-871 and BY16-853U manufactured by Dow Corning Toray Co.,

(Acid anhydride (a1) and acid anhydride (a2))

Examples of the acid anhydride (a1) and the acid anhydride (a2) include tricarboxylic acid anhydrides having at least one of an aromatic ring and an aliphatic ring, and trimellitic anhydride (benzene- 2,4-tricarboxylic acid 1,2-anhydride, TMA), and the like having an aliphatic ring such as hydrogenated trimellitic anhydride (cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, H-TMA), and the like. These acid anhydrides may be used singly or in combination of two or more.

In the present invention, as the acid anhydride, it is necessary to use the tricarboxylic acid anhydride, but carboxylic acid dianhydride may be used in combination. Examples of the carboxylic acid dianhydride include tetracarboxylic acid anhydrides such as pyromellitic dianhydride and 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride. Further, both end-type carboxylic acid anhydride-modified silicones and the like can be mentioned.

(Diisocyanate compound)

As the diisocyanate compound, diisocyanates such as aromatic diisocyanates and isomers or isomers thereof, aliphatic diisocyanates, alicyclic diisocyanates and isomers thereof, and other general diisocyanates can be used, but the present invention is not limited thereto no. These diisocyanates may be used singly or in combination.

Specific examples of the diisocyanate include 4,4'-diphenylmethane diisocyanate (MDI), tolylene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, biphenyl diisocyanate, diphenylsulfone diisocyanate, di Aromatic diisocyanates such as benzene diisocyanate and phenyl ether diisocyanate, and isomers thereof, oligomers, hexamethylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate, xylene diisocyanate and trimethylhexamethylene diisocyanate Alicyclic diisocyanates, alicyclic diisocyanates obtained by hydrogenating the above aromatic diisocyanates and isomers, or other general-purpose diisocyanates.

As described above, the reaction raw material for obtaining the polyamideimide resin may further contain, in addition to the imide and diisocyanate compounds, the same acid anhydride (a2) as used for obtaining the imide. The content of the acid anhydride (a2) in the reaction raw material in this case is not particularly limited. From the viewpoint of improving the balance between the alkali solubility of the polyamide-imide resin and the mechanical properties of the resulting cured product, the amount of the acid anhydride (a2) in the reaction raw material relative to the amount of the diamine used to obtain the imide in the reaction raw material Is preferably 0.25 or more and 4 or less, more preferably 0.5 or more and 2 or less, and particularly preferably 0.6 or more and 1.5 or less.

The content of the diisocyanate compound in the reaction raw material is not particularly limited either. From the viewpoint of improving the balance between the alkali solubility of the polyamide-imide resin and the mechanical properties of the resulting cured product, the amount of the diisocyanate compound in the reaction raw material is preferably from 1 to 100 parts by weight, based on the amount of the diamine used for obtaining the imide in the reaction raw material, The molar ratio with respect to the total amount of the acid anhydrides (a2) contained in the raw material is preferably 0.3 or more and 1.0 or less, more preferably 0.4 or more and 0.95 or less, and particularly preferably 0.50 or more and 0.90 or less.

In particular, use of a diamine having an ether bond and H-TMA, which is an alicyclic trimellitic acid, is preferable because the alkali solubility of the obtained (A) polyamideimide resin is enhanced and the developability is improved . For the same reason, it is also preferable to use an aliphatic diisocyanate in the second-step reaction. Since the imide structure takes a stacking structure in which the molecular chains are filled with each other, it is considered that the solubility in a solvent or an aqueous alkali solution is low, but the stacking structure is broken by introducing a fatty chain or an alicyclic structure, thereby increasing alkali solubility.

In the present invention, the polyamideimide resin (A) preferably has an aliphatic structure and an ether bond. As the aliphatic structure in this case, straight chain hexane or cyclic cyclohexane can be mentioned. The ether bond is preferably a polyether structure having a molecular weight of 200 or more. Most of the imide resin has a strong alkali / solvent developability, but by introducing an aliphatic structure or an ether bond, particularly a polyether structure, the polyamideimide resin (A) has weak alkali developability, deep resolution and bendability . The aliphatic structure can be introduced, for example, by using a carboxylic acid monoanhydride having an aliphatic ring, or by using an isocyanate having an aliphatic structure, and the ether bond can be introduced, for example, by reacting a diamine having the above- Can be introduced. As the diamine having an ether bond, a diamine having a molecular weight of 200 or more is preferable.

The amide bond of the polyamide-imide resin (A) may be obtained by reacting an isocyanate with a carboxylic acid, or may be a reaction other than the reaction. The polyamideimide resin (A) may further have a bond formed by addition and condensation.

In the present invention, the blending ratio of each component in obtaining the polyamide-imide resin (A) is preferably 2.0 to 2.4 moles, more preferably 2.0 to 2.2 moles, of the acid anhydride per mole of the diamine . The reaction temperature when the diamine is reacted with the acid anhydride and imidized by dehydration ring closure is not particularly limited, but it is preferably within the range of 140 to 200 캜. The reaction temperature of the imide compound obtained by reacting the diamine with the acid anhydride and the diisocyanate compound is not particularly limited, but is preferably in the range of 130 to 200 ° C.

The polyamideimide resin (A) preferably has an acid value of 50 mgKOH / g or more, more preferably 50 to 200 mgKOH / g, more preferably 70 to 130 mgKOH / g, g. When the acid value is 50 mgKOH / g or more, the solubility in an alkali is increased, the developability is improved, and further the degree of crosslinking with the thermosetting component after irradiation is increased, so that sufficient development contrast can be obtained. On the other hand, if the acid value is 200 mgKOH / g or less, so-called thermal fogging in the post-exposure bake (PEB) process after light irradiation described later can be suppressed, and the process margin becomes large.

The molecular weight of the polyamideimide resin (A) is preferably 10,000 or less, more preferably 1,000 to 8,000, and still more preferably 2,000 to 6,000, in view of the developability and cured coating film characteristics. When the molecular weight is 10,000 or less, the alkali solubility of the unexposed portion is increased and the developability is improved. On the other hand, when the molecular weight is 1000 or more, sufficient development resistance and cured properties can be obtained after exposure and PEB in the exposed part.

[(B) Photobase generator]

The photobase generator (B) is a compound capable of functioning as a catalyst for the addition reaction between a polyimide resin having a carboxyl group and a thermosetting component by changing the molecular structure or cleaving the molecule by irradiation of light such as ultraviolet rays or visible light A compound that produces a basic or more basic substance. Examples of the basic substance include a secondary amine and a tertiary amine.

Examples of the photobase generator include an? -Amino acetophenone compound, an oxime ester compound, an acyloxyimino group, an N-formylated aromatic amino group, a N-acylated aromatic amino group, a nitrobenzyl carbamate group, And a compound having a substituent such as a carboxylate group and a carboxylate group. Of these, oxime ester compounds and? -Aminoacetophenone compounds are preferable. As the? -amino acetophenone compound, those having at least two nitrogen atoms are particularly preferred.

(E) -1- [3- (2-heptylcarbamate), WPBG-027 (trade name: WPBG-082 (trade name: guanidinium 2- (3-benzoylphenyl) propionate), WPBG-140 (trade name: 1- (anthraquinone- -Yl) ethylimidazole carboxylate) or the like may be used.

The? -aminoacetophenone compound has a benzoin ether bond in its molecule, and when exposed to light, cleavage occurs in the molecule, and a basic substance (amine) is produced which exhibits a curing catalytic action. Specific examples of the? -amino acetophenone compound include (4-morpholinobenzoyl) -1-benzyl-1-dimethylaminopropane (Irgacure 369, trade name, manufactured by BASF Japan) (Methylthiobenzoyl) -1-methyl-1-morpholinoethane (Irgacure 907, trade name, manufactured by BASF Japan) A commercially available compound such as 1- [4- (4-morpholinyl) phenyl] -1-butanone (Irgacure 379, trade name, manufactured by BASF Japan) or a solution thereof may be used.

As the oxime ester compound, any compound capable of generating a basic substance by light irradiation can be used. Examples of such oxime ester compounds include CGI-325, Irgacure OXE01, Irgacure OXE02 manufactured by BASF Japan Co., Ltd., N-1919 and NCI-831 manufactured by ADEKA CORPORATION. A compound having two oxime ester groups in the molecule described in Japanese Patent No. 4344400 can also be suitably used.

In addition, Japanese Patent Application Laid-Open Nos. 2004-359639, 2005-097141, 2005-220097, 2006-160634, 2008-094770 Carbazole oxime ester compounds described in Japanese Patent Application Laid-Open No. 2008-509967, Japanese Patent Laid-Open Nos. 2009-040762 and 2011-80036, and the like.

These photobase generators may be used alone or in combination of two or more. The blending amount of the photo-base generator in the photosensitive thermosetting resin composition is preferably 0.1 to 40 parts by mass, more preferably 0.1 to 30 parts by mass based on 100 parts by mass of the thermosetting component. When the compounding amount of the photobase generator is 0.1 parts by mass or more, the contrast of the developability of the light irradiating portion / non-irradiated portion can be satisfactorily obtained. When the blending amount of the photo-base generator is 40 parts by mass or less, the properties of the cured product are improved.

[(C) Thermal curing component]

(C) The thermosetting component has a functional group capable of addition reaction with a carboxyl group or a phenolic hydroxyl group by heat. As the thermosetting component, for example, a cyclic ether compound having a cyclic (thio) ether group is preferable, and an epoxy resin, a polyfunctional oxetane compound, and the like can be given.

The epoxy resin is a resin having an epoxy group, and any known epoxy resin can be used, and a bifunctional epoxy resin having two epoxy groups in the molecule and a polyfunctional epoxy resin having a large number of epoxy groups in the molecule. It may also be a hydrogenated bifunctional epoxy compound.

Examples of the epoxy compounds include bisphenol A epoxy resins, brominated epoxy resins, novolak epoxy resins, bisphenol F epoxy resins, hydrogenated bisphenol A epoxy resins, glycidylamine epoxy resins, hydantoin epoxy resins, Type epoxy resin, trihydroxyphenylmethane type epoxy resin, biquileneol type or biphenol type epoxy resin or a mixture thereof; A bisphenol S type epoxy resin, a bisphenol A novolak type epoxy resin, a tetraphenylol ethane type epoxy resin, a heterocyclic epoxy resin, a diglycidyl phthalate resin, a tetraglycidylsilaneoyl ethane resin, a naphthalene group containing epoxy resin, An epoxy resin having a chloropentadiene skeleton, a glycidyl methacrylate copolymer-based epoxy resin, a copolymerized epoxy resin of cyclohexylmaleimide and glycidyl methacrylate, and a CTBN-modified epoxy resin.

Examples of other liquid bifunctional epoxy resins include vinylcyclohexene diepoxide, (3 ', 4'-epoxycyclohexylmethyl) -3,4-epoxycyclohexanecarboxylate, (3', 4'- 6'-methylcyclohexylmethyl) -3,4-epoxy-6-methylcyclohexanecarboxylate, and the like. These epoxy resins may be used singly or in combination of two or more kinds.

In addition, known publicly known compounds such as a maleimide compound, a block isocyanate compound, an amino resin, a benzoxazine resin, a carbodiimide resin, a cyclocarbonate compound and an episulfide resin may be blended as the (C) thermosetting component It is possible.

The amount of the thermosetting component (C) to be blended is preferably 10: 1 to 1:10 in terms of equivalence ratio (carboxyl group: thermal reactive group such as epoxy group) to the polyamideimide resin (A). By setting the mixing ratio within such a range, the developing property becomes satisfactory, and a fine pattern can be easily formed. The equivalent ratio is more preferably from 10: 2 to 2:10.

[(D) Polyimide resin]

The photosensitive thermosetting resin composition of the present invention preferably further comprises (D) a polyimide resin having an imide ring and a phenolic hydroxyl group. When the phenolic hydroxyl group is present, it is possible to lengthen the time until it becomes alkali-resistant by the addition reaction under the same heating temperature in the heat hardening reaction (PEB) step after exposure, It is also possible to broaden the selection range of the heating temperature during the PEB process. As a result, the workability and handleability of the photosensitive thermosetting resin composition are improved. It is also possible to suppress the occurrence of so-called blurring, in which the unexposed portion becomes alkali resistant. Such a (D) polyimide resin can be synthesized by using an amine component having a phenolic hydroxyl group or an isocyanate component as a raw material.

The polyimide resin (D) is preferably an imide ring and has a partial structure represented by the following formula (1). In the formula (1), it is more preferable that R includes an aromatic ring.

It is more preferable that the partial structure represented by the formula (1) is represented by the following formula (2) or (3).

The polyimide resin (D) preferably has a carboxyl group in addition to an imide ring and a phenolic hydroxyl group, and the position of the carboxyl group in this case is not particularly limited. A carboxyl group may be present as a substituent of the imidazole ring or a group bonding thereto, and a carboxyl group may be introduced into the polyimide resin by carrying out the synthesis using a compound having a carboxyl group as an amine component or an isocyanate component described later.

For the synthesis of the polyimide resin (D), publicly known methods can be used. For example, a method of reacting one or both of carboxylic acid anhydride component, amine component and isocyanate component can be used. The imidization may be carried out by thermal imidization, by chemical imidization, or by using them in combination.

As the carboxylic acid anhydride component, carboxylic acid monoanhydrides and carboxylic acid dianhydrides exemplified for the polyamideimide resin (A) can be used. However, the carboxylic acid anhydrides are not limited to these acid anhydrides but may be those which react with amino groups or isocyanate groups As the compound having an acid anhydride group and a carboxyl group, a derivative thereof can be used. These carboxylic acid anhydride components may be used alone or in combination of two or more.

Examples of the amine component having a phenolic hydroxyl group include diamino phenols such as 2,4-diaminophenol, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-dia 3,3'-dihydroxybiphenyl, 4,4'-diamino-2,2'-dihydroxybiphenyl, 4,4'-diamino-2,2 ', 5,5'- Tetrahydroxybiphenyl and the like, 3,3'-diamino-4,4'-dihydroxydiphenylmethane, 4,4'-diamino-3,3'-dihydroxy Dihydroxydiphenylmethane, 2,2-bis [3-amino-4-hydroxyphenyl] propane, 2,2-bis [4- Amino-3-hydroxyphenyl] propane, 2,2-bis [3-amino-4-hydroxyphenyl] hexafluoropropane, 4,4'-diamino-2,2 ', 5,5'-tetra Hydroxydiphenylalkanes such as hydroxydiphenylmethane, such as hydroxydiphenylmethane, 3,3'-diamino-4,4'-dihydroxydiphenyl ether, 4,4'-diamino-3 , 3'-dihydroxydiphenyl ether, 4,4'-diamino-2,2'- Hydroxydiphenyl ether compounds such as hydroxydiphenyl ether, 4,4'-diamino-2,2 ', and 5,5'-tetrahydroxydiphenyl ether, and 3,3'-diamino-4,4 Dihydroxydiphenyl sulfone, 4,4'-diamino-3,3'-dihydroxydiphenyl sulfone, 4,4'-diamino-2,2'-dihydroxydiphenyl sulfone, 4 , 4'-diamino-2, 2 ', 5,5'-tetrahydroxydiphenylsulfone, and the like; 2,2-bis [4- (4-amino- Bis (hydroxyphenyl) phenyl] alkane compounds such as 4,4'-bis (4-amino-3-hydroxyphenoxy) biphenyl, (Hydroxyphenoxy) phenyl] sulfone compounds such as 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] sulfone and the like, 4,4'- 3'-dihydroxydiphenylmethane, 4,4'-diamino-2,2'-dihydroxydiphenylmethane, and other carboxyphenylalkanes such as 4,4'-diamino-2,2'- Dihydroxydiphenylmethane, 4,4'-bis Bis (hydroxyphenoxy) biphenyl compounds such as bis (4-amino-3-hydroxyphenoxy) biphenyl, And bis (hydroxyphenoxy) benzene compounds such as 3-bis (4-amino-3-hydroxyphenoxy) benzene. These amine components may be used alone or in combination.

As the isocyanate component, the diisocyanate exemplified for the polyamideimide resin (A) may be used singly or in combination.

The molecular weight of the polyimide resin (D) is preferably from 1,000 to 100,000, more preferably from 2,000 to 50,000, in view of the developability after exposure and PEB, the developability and the cured coating film characteristics.

A thermosetting catalyst may be incorporated into the photosensitive thermosetting resin composition of the present invention. The thermosetting catalyst is used to further improve the thermosetting property of the thermosetting component (C), and examples thereof include amine compounds such as dicyandiamide and aromatic amine, imidazoles, phosphorus compounds, acid anhydrides, A diene compound and the like can be used. Specific examples include imidazole, 1-benzyl-2-phenylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, Imidazoles such as 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole and 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; Amines such as dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine and 4- A phosphorus compound such as triphenylphosphine, or the like can be used. More specifically, 1B2PZ, 2E4MZ, 2MZ-A, 2MZ-OK, 2PHZ, 2P4MHZ (manufactured by Shikoku Kasei Kogyo Co., Ltd.) as the imidazole compound; As the block isocyanate compound of dimethylamine, U-CAT3503N, -3502T (manufactured by San-Pa); DBU, DBN, U-CAT SA102, U-CAT5002 (manufactured by San-apro Co., Ltd.) and the like can be mentioned as the 2-cyclic amidine compound and its salt. These may be used singly or in combination of two or more.

The content of the thermosetting catalyst is usually sufficient, for example, 0.1 part by mass to 10 parts by mass with respect to 100 parts by mass of the thermosetting component (C).

An inorganic filler may be blended in the photosensitive thermosetting resin composition of the present invention. The inorganic filler is used for suppressing curing shrinkage of the cured product of the photosensitive thermosetting resin composition and for improving the properties such as adhesion and hardness. Examples of the inorganic filler include inorganic fillers such as barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, , Neuburg siliceous earth, and the like. These may be used singly or in combination of two or more.

A colorant may be added to the photosensitive thermosetting resin composition of the present invention. As the colorant, conventionally known colorants such as red, blue, green, yellow, white, and black can be used, and pigments, dyes, and pigments can be used.

In the photosensitive thermosetting resin composition of the present invention, a publicly known polymer resin may be blended for the purpose of improving flexibility and tack-drying property of the resulting cured product. Examples of the polymer resin include cellulose-based, polyester-based, and phenoxy-based polymers, polyvinyl acetal based, polyvinyl butyral based, polyamide based, polyimide based, polyamideimide based binder polymers, block copolymers and elastomers . One kind of the polymer resin may be used alone, or two or more kinds may be used in combination.

In the photosensitive thermosetting resin composition of the present invention, an organic solvent may be used for the preparation of a resin composition or for viscosity adjustment when applied to a substrate or a carrier film. Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents and the like. These organic solvents may be used singly or as a mixture of two or more kinds.

The photosensitive thermosetting resin composition of the present invention may further contain known additives such as photopolymerizable monomers, mercapto compounds, adhesion promoters (adhesion promoters), antioxidants, ultraviolet absorbers, thickeners, defoamers, leveling agents, silane coupling agents, May be further added. Examples of the thickening agent include fine silica, hydrotalcite, organic bentonite, and montmorillonite. Examples of the antifoaming agent include silicone, fluorine, and high molecular weight. The blending amount of the photopolymerizable monomer is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and most preferably 0 parts by mass (not including) in 100 parts by mass of the polyamide-imide resin (A) Do.

The cured product obtained by the photosensitive thermosetting resin composition of the present invention is excellent in flexibility and heat resistance and can be further finely processed by alkali development. Therefore, according to the present invention, an alkali developing photosensitive resin composition The flexible printed wiring board can be used in any of the bent portion and the mounting portion of the flexible printed wiring board and is suitable for the batch forming process of the bent portion and the mounting portion.

The dry film of the present invention is characterized by having a resin layer containing the photosensitive thermosetting resin composition of the present invention. In the case of dry film formation, for example, the photosensitive thermosetting resin composition of the present invention is diluted with an organic solvent, adjusted to a suitable viscosity, and coated on the carrier film to a uniform thickness by a known method such as a comma coater. Then, the resin layer is formed on the carrier film by drying at a temperature of usually 50 to 130 ° C for 1 to 30 minutes.

As the carrier film, a plastic film is used. The thickness of the carrier film is not particularly limited, but is generally appropriately selected in the range of 10 to 150 mu m. After the resin layer is formed on the carrier film, a peelable cover film may be further laminated on the surface of the resin layer.

The printed wiring board of the present invention is characterized in that it comprises a cured product formed by using the photosensitive thermosetting resin composition of the present invention or the dry film of the present invention. Since the photosensitive thermosetting resin composition of the present invention is excellent in flexibility, the printed wiring board of the present invention is particularly useful as a flexible printed wiring board.

When a resin insulating layer of a printed wiring board is formed using the photosensitive thermosetting resin composition of the present invention, a suitable production method is as follows. That is, the method includes the steps of forming a resin layer containing the photosensitive thermosetting resin composition of the present invention on a printed wiring board, a step of irradiating the resin layer with light in the form of a pattern, a step of heating the resin layer (PEB) And forming a resin insulating layer having a pattern. If necessary, after the alkali development, further light irradiation or heat curing (post curing) is performed to completely cure the resin composition to obtain a highly reliable resin insulating layer. In the photosensitive thermosetting resin composition of the present invention, by the catalytic action of the base generated from the photobase generator (B) by light irradiation, the (A) the carboxyl group of the polyamideimide resin and By the addition reaction of the curing component, it becomes possible to form a negative pattern by the alkali development.

[Resin Layer Forming Step]

In this step, at least one resin layer containing the photosensitive thermosetting resin composition is formed on the printed wiring board. Examples of the method for forming the resin layer include a coating method and a lamination method. In the case of the coating method, the photosensitive thermosetting resin composition is coated on a printed wiring board by a method such as screen printing and dried to form a resin layer. In the case of the lamination method, first, the photosensitive thermosetting resin composition is diluted with an organic solvent, adjusted to an appropriate viscosity, coated on a carrier film, and dried to prepare a dry film having a resin layer. Next, the dry film is bonded to the printed wiring board by a laminator or the like so that the resin layer comes into contact with the printed wiring board, and then the carrier film is peeled off.

Here, another layer may be interposed between the resin layer and the printed wiring board. Such another layer preferably contains an alkali developing photosensitive resin composition. As the alkali developing type photosensitive resin composition, a known composition can be used, and for example, a known composition for coverlay or solder resist can be used. By adopting such a laminated structure including other layers, it is possible to obtain a cured product having further improved impact resistance and flexibility.

[Light irradiation step]

In this step, the photo-base generating agent contained in the resin layer is activated on the negative-type pattern by light irradiation to cure the light-irradiated portion. In this step, the base of the photocatalyst is destabilized by the base generated in the light irradiation portion, and the base is chemically grown, so that the core portion of the resin layer can be sufficiently cured. As the light irradiator, a direct drawing apparatus, a light irradiator equipped with a metal halide lamp, or the like can be used. The mask for light irradiation on the pattern is a negative type mask.

As the active energy ray used for light irradiation, it is preferable to use laser light or scattered light having a maximum wavelength in the range of 350 to 450 nm. By setting the maximum wavelength within this range, the photobase generator can be efficiently activated. If a laser beam of this range is used, either a gas laser or a solid laser is preferable. In addition, although the amount of light to be irradiated differs depending on the film thickness and the like, it is generally 100 to 1500 mJ / cm 2.

[Heating process]

In this step, the light irradiation part is cured by heating the resin layer after the light irradiation. By this step, the base can be cured by the base generated in the light irradiation step. The heating temperature is, for example, 80 to 140 占 폚. The heating time is, for example, 1 to 100 minutes. Since the curing of the photosensitive thermosetting resin composition in the present invention is a ring-opening reaction of an epoxy resin by, for example, a thermal reaction, distortion and curing shrinkage can be suppressed as compared with the case where curing is progressed by a photo radical reaction.

[Development process]

In this step, the light irradiation portion is removed by alkali development to form a negative pattern-like insulating film, in particular a coverlay and a solder resist. As the developing method, a known method such as dipping can be used. As the developing solution, an aqueous alkali solution such as sodium carbonate, potassium carbonate, potassium hydroxide, amines, imidazoles such as 2-methylimidazole, aqueous solution of tetramethylammonium hydroxide (TMAH), or a mixture thereof can be used. Further, the insulating film may be irradiated with light again after the development step. Further, it may be heated at 150 DEG C or higher, for example.

Next, an example of a method for producing a flexible printed wiring board from the photosensitive thermosetting resin composition of the present invention will be described based on the process of Fig. In Fig. 1, the case where the resin layer has a laminated structure is shown, but it may be a case where the resin layer consists of only one layer.

1, a laminated structure including a resin layer 3 and a resin layer 4 is formed on a flexible printed wiring board 1 on which a copper circuit 2 is formed. The resin layer (3) includes an alkali developing type photosensitive resin composition containing a carboxyl group-containing resin or the like. Further, the resin layer 4 includes the photosensitive thermosetting resin composition of the present invention comprising the polyamideimide resin, photo base generator and thermosetting component.

In the light irradiation step of FIG. 1, the photomask generating agent contained in the photosensitive thermosetting resin composition is activated by disposing the mask 5 on the resin layer 4 and irradiating light in the form of a negative pattern, It is a curing process. The heating step of FIG. 1 is a step (PEB step) of hardening the light irradiation part by heating the resin layer after the light irradiation step. The developing step shown in Fig. 1 is a step of developing with an alkaline aqueous solution to remove a non-irradiated portion to form a negative pattern layer.

In addition, the second light irradiation step of FIG. 1 is a step for activating the remaining photo-base generating agent as needed to generate a base, and the heat curing step is a step for sufficiently curing the pattern layer as necessary.

[Examples]

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

≪ Synthesis Example 1: Synthesis Example of Polyamideimide Resin Solution >

Diaminobenzoic acid and 3.8 g of 2,2'-bis [4- (4-aminophenoxy) phenyl] pyridine were placed in a separable three-necked flask equipped with a stirrer, 6.98 g of propane, 8.21 g of Zephamin XTJ-542 (manufactured by Huntsman, molecular weight 1025.64) and 86.49 g of? -Butyrolactone were added and dissolved at room temperature.

Subsequently, 17.84 g of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride and 2.88 g of trimellitic anhydride were added and kept at room temperature for 30 minutes. Subsequently, 30 g of toluene was added, the temperature was raised to 160 캜, and toluene and water were distilled off while stirring for 3 hours, followed by cooling to room temperature to obtain an imide freed solution.

9.61 g of trimellitic anhydride and 17.45 g of trimethylhexamethylene diisocyanate were added to the obtained imide cargo solution, and the mixture was stirred at a temperature of 160 캜 for 32 hours. Thus, a polyamide-imide resin solution (PA-1) having a carboxyl group was obtained. The obtained resin solution (PA-1) had a solid content of 40.1% by mass and an acid value of solid content of 83.1 mgKOH.

Synthesis Example 2: Synthesis of polyimide resin solution having imide ring, phenolic hydroxyl group and carboxyl group>

In a separable three-necked flask equipped with a stirrer, a nitrogen introducing tube, a fractionating tube and a cooling tube, 22.4 g of 3,3'-diamino-4,4'-dihydroxydiphenyl sulfone, 8.2 g of 4- (4-aminophenoxy) phenyl] propane, 30 g of NMP, 30 g of? -Butyrolactone, 27.9 g of 4,4'-oxydiphthalic anhydride and 3.8 g of trimellitic anhydride , And the mixture was stirred at 100 rpm for 4 hours at room temperature under a nitrogen atmosphere. Subsequently, 20 g of toluene was added, and the mixture was stirred for 4 hours while distilling toluene and water at a silicon bath temperature of 180 캜 at 150 rpm to obtain an alkali soluble resin solution having an imide ring.

The obtained resin (solid content) had an acid value of 18 mgKOH, a Mw of 10,000, and a hydroxyl group equivalent of 390.

≪ Preparation of Photosensitive Thermosetting Resin Composition >

The materials described in the examples and the comparative examples were each compounded in accordance with the formulation shown in the following Table 1, premixed in a stirrer, and kneaded by a three-roll mill to prepare a photosensitive thermosetting resin composition. Incidentally, the value of the blending amount in the table indicates the mass part of the solid content, unless otherwise specified.

A flexible printed wiring board having a circuit of a copper thickness of 18 mu m was prepared, and preprocessing was carried out using Macblight CB-801Y manufactured by Merck. Thereafter, each of the photosensitive thermosetting resin compositions was applied to the pretreated flexible printed wiring substrate so as to have a film thickness after drying of 25 mu m. Thereafter, the resultant was dried in a hot air circulation type drying oven at 90 DEG C for 30 minutes to form a coating film containing the photosensitive thermosetting resin composition.

<Evaluation of Alkali Developability (Patterning) and Flexibility>

The base material provided with the coating film obtained above was irradiated with HMW680GW (metal halide lamp, scattered light) manufactured by ORC Co., Ltd. in a negative patterned state at an exposure amount of 500 mJ / cm 2. Subsequently, heat treatment was performed at 90 占 폚 for 60 minutes. Subsequently, the substrate was immersed in an aqueous sodium carbonate solution at 30 占 폚 and 1 mass%, and development was carried out for 3 minutes to evaluate the alkali developing property.

Subsequently, heat treatment was performed at 150 占 폚 for 60 minutes using a hot air circulation type drying furnace to obtain a patterned cured coating film. The obtained cured coating film was subjected to MIT test (R = 0.38 mm / using a substrate of 12.5 탆 of UFIREX made by UBE KOGAN CO., LTD.) To evaluate the flexural properties. If it is about 120 cycles or more, flexibility as a flexible printed wiring board can be satisfied.

<Resolution>

A cured product pattern of each photosensitive thermosetting resin composition having a film thickness of 25 mu m and an opening diameter of? 200 mu m was formed on copper and observed with an SEM (scanning electron microscope). The obtained opening shape was confirmed and evaluated according to the following criteria.

Good: Good opening shape

X: Poor opening shape

Note: The compounding amount in the table is expressed as solid content (parts by mass).

* 1) Polyamideimide resin 1, PA-1 (Resin of Synthesis Example 1)

* 2) Polyamideimide resin 2 (having imide ring and amide bond), SOXR-M, manufactured by Nippon Kodoshi Kogyo Co., Ltd. Acid value Molecular weight 10700

* 3) Alkali developable resin 1, manufactured by Negami Chemical Industry Co., Ltd., acid value: 50 mgKOH / g Polyurethane

* 4) Alkali developing resin 2, manufactured by Kyoeisha Chemical Co., Ltd., acid value 47 mgKOH / g Polyurethane acrylate

* 5) Alkali developable resin 3, manufactured by Nippon Kayaku Co., Ltd. Acid value 98 mgKOH / g Bisphenol F type acrylate resin

* 6) imide resin (having a phenolic hydroxyl group and a carboxyl group), PI-1 (resin of Synthesis Example 2)

* 7) E828, manufactured by Mitsubishi Chemical Corp., bisphenol A type epoxy resin, epoxy equivalent 190 g / eq

* 8) OXE02, manufactured by BASF Japan Ltd., oxime-based photopolymerization initiator

As is evident from the evaluation results shown in Table 1, the photosensitive thermosetting resin compositions of the respective Examples were found to have excellent developability and resolution as well as good bendability. On the other hand, in Comparative Example 1, a polyamide-imide resin having no carboxyl group was used, and (C) the thermosetting component was not blended, and thus the developability and resolution were not obtained. From the results of Comparative Examples 2 to 4, it can be seen that when an alkali developable resin other than the polyamide-imide resin is used, the developability and the resolution are satisfactory but the flexibility is insufficient.

1 flexible printed wiring board
2 copper circuit
3 resin layer
4 resin layer
5 Mask

Claims (13)

(A) obtained by reacting an imide compound obtained by reacting at least one diamine containing a carboxyl group-containing diamine (a) with an acid anhydride (a1) containing a tricarboxylic acid anhydride and a reaction raw material containing a diisocyanate compound, Amide imide resins,
(B) a photobase generator, and
(C) a thermosetting component
Wherein the thermosetting resin composition is a thermosetting resin composition. The photosensitive thermosetting resin composition according to claim 1, wherein the acid anhydride (a1) comprises either or both of trimellitic anhydride and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. The photosensitive thermosetting resin composition according to claim 1 or 2, wherein the reaction raw material further comprises a tricarboxylic acid anhydride (a2). The photosensitive thermosetting resin composition according to claim 3, wherein the acid anhydride (a2) comprises trimellitic anhydride and / or cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. The photosensitive thermosetting resin composition according to any one of claims 1 to 4, wherein the (A) polyamideimide resin further has an aliphatic structure and an ether bond. The photosensitive thermosetting resin composition according to claim 5, wherein the aliphatic structure of the polyamide-imide resin (A) is hexane or cyclohexane. The photosensitive thermosetting resin composition according to claim 5 or 6, wherein the (A) ether bond of the polyamideimide resin has a polyether structure derived from a diamine having an ether bond and the molecular weight of the diamine having the ether bond is 200 or more . The photosensitive thermosetting resin composition according to any one of claims 1 to 7, further comprising (D) a polyimide resin having an imide ring and a phenolic hydroxyl group. The photosensitive thermosetting resin composition according to claim 8, wherein the polyimide resin (D) further comprises a carboxyl group. The photosensitive thermosetting resin composition according to any one of claims 1 to 9, wherein the (C) thermosetting component is a cyclic ether compound. 11. The photosensitive thermosetting resin composition according to any one of claims 1 to 10, which is used for a flexible printed wiring board. A dry film having a resin layer comprising the photosensitive thermosetting resin composition according to any one of claims 1 to 11. A printed wiring board characterized by comprising a cured product formed by using the photosensitive thermosetting resin composition according to any one of claims 1 to 11 or the dry film according to claim 12.

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