JP6568715B2 - Photosensitive thermosetting resin composition, dry film and printed wiring board - Google Patents

Description

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

  In recent years, as electronic devices have become smaller and thinner due to the spread of smartphones and tablet terminals, it has become necessary to reduce the space of circuit boards. For this reason, flexible printed circuits that can be folded and stored have expanded the uses of wiring boards, and flexible printed wiring boards are required to have higher reliability than ever.

  On the other hand, as an insulating film to ensure the insulation reliability of flexible printed wiring boards, a cover based on polyimide with excellent mechanical properties such as heat resistance and flexibility is used for the bent part (bent part). Using a lay (see, for example, Patent Documents 1 and 2), the mounting part (non-bent part) has a mixed mounting process using a photosensitive resin composition that is excellent in electrical insulation and solder heat resistance and can be finely processed. Widely adopted.

  That is, a cover lay based on polyimide is not suitable for fine wiring because it requires processing by die punching. Therefore, it is necessary to partially use an alkali developing type photosensitive resin composition (solder resist) that can be processed by photolithography in a chip mounting portion that requires fine wiring.

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

  As described above, the conventional flexible printed wiring board manufacturing process has to employ a mixed mounting process of bonding the coverlay and forming the solder resist, which is inferior in cost and workability. It was.

  On the other hand, in the past, 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. The material has not yet been put to practical use. Especially for flexible printed circuit boards, durability against bending is the most important, so it is applicable to solder resists and coverlays for flexible printed circuit boards, and the realization of materials with excellent durability against bending is required. It was.

  Accordingly, an object of the present invention is a photosensitive thermosetting resin composition that has excellent flexibility and is suitable for a batch forming process of an insulating film of a flexible printed wiring board, particularly a bent portion (bent portion) and a mounting portion (non-bent portion). It is to provide a printed wiring board having the cured product as a protective film, for example, a cover lay or a solder resist.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by a resin composition containing a specific polyamideimide resin, a photobase generator, and a thermosetting component. It came to be completed.

  That is, the photosensitive thermosetting resin composition of the present invention is an imide obtained by reacting (A) at least one diamine containing a carboxyl group-containing diamine with an acid anhydride (a1) containing a tricarboxylic acid anhydride. A polyamideimide resin obtained by reacting a reaction raw material containing a chemical compound with a diisocyanate compound, (B) a photobase generator, and (C) a thermosetting component.

  In the present invention, the acid anhydride (a1) preferably contains one or both of trimellitic acid anhydride and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. . Moreover, it is preferable that the said reaction raw material further contains a tricarboxylic acid anhydride (a2). Further, the acid anhydride (a2) preferably contains either one or both of trimellitic anhydride and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. Furthermore, it is preferable that the (A) polyamideimide resin further has an aliphatic structure and an ether bond. In this case, the aliphatic structure of the (A) polyamideimide resin is preferably 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 an ether bond is 200 or more.

  Furthermore, 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, the (D) polyimide resin further contains a carboxyl resin. It is more preferable to have a group. Furthermore, in the present invention, the (C) thermosetting component is preferably a cyclic ether compound. The photosensitive thermosetting resin composition of this invention can be used suitably for a flexible printed wiring board.

  Moreover, the dry film of this invention has a resin layer which consists of the said photosensitive thermosetting resin composition of this invention, It is characterized by the above-mentioned. Furthermore, 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, a photosensitive thermosetting resin composition that is excellent in flexibility and suitable for a batch forming process of an insulating film of a flexible printed wiring board, particularly a bent portion (bent portion) and a mounting portion (non-bent portion). And a printed wiring board having the cured product as a protective film can be realized.

It is process drawing which shows typically an example of the manufacturing method of the flexible printed wiring board of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
The photosensitive thermosetting resin composition of the present invention comprises (A) an imidized product obtained by reacting (A) at least one diamine containing a carboxyl group-containing diamine with an acid anhydride (a1) containing a tricarboxylic acid anhydride. And a polyamideimide resin obtained by reacting a reaction raw material containing a diisocyanate compound, (B) a photobase generator, and (C) a thermosetting component.

In the photosensitive thermosetting resin composition of the present invention, a photobase generator is activated by light irradiation, and a polyamideimide resin having a carboxyl group and a thermosetting component are subjected to an addition reaction by heating using the generated base as a catalyst. As a result, it is possible to remove only the unexposed portion with an alkali solution, and this enables fine processing by alkali development, while it can be expected to obtain a cured product having excellent reliability. Since the photosensitive thermosetting resin composition of the present invention has excellent flexibility and good developability and resolution, it is suitable for resin insulating layers of flexible printed wiring boards, such as coverlays and solder resists. is there.
Hereinafter, each component which comprises the photosensitive thermosetting resin composition of this invention is explained in full detail.

[(A) Polyamideimide resin]
The (A) polyamideimide resin used in the present invention is obtained after reacting at least one diamine containing a carboxyl group-containing diamine with an acid anhydride (a1) containing a tricarboxylic acid anhydride to obtain an imidized product. The reaction raw material containing the imidized product and the diisocyanate compound is further reacted. As will be described later, the reaction raw material preferably further contains a tricarboxylic acid anhydride (a2) in addition to the imidized product and the diisocyanate compound.

(Diamine)
Examples of the carboxyl group-containing diamine include 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, diaminobenzoic acids such as 3,4-diaminobenzoic acid, and 3,5-bis (3-aminophenoxy) benzoic acid. Acid, aminophenoxybenzoic acids such as 3,5-bis (4-aminophenoxy) benzoic acid, 3,3′-methylenebis (6-aminobenzoic acid), 3,3′-diamino-4,4′-dicarboxyl Biphenyl, 4,4′-diamino-3,3′-dicarboxybiphenyl, 4,4′-diamino-2,2′-dicarboxybiphenyl, 4,4′-diamino-2,2 ′, 5,5 ′ Carboxyphenyl compounds such as tetracarboxybiphenyl, 3,3′-diamino-4,4′-dicarboxydiphenylmethane, 3,3′-dicarboxy-4,4′-diaminodipheny Methane, 2,2-bis [3-amino-4-carboxyphenyl] propane, 2,2-bis [4-amino-3-carboxyphenyl] propane, 2,2-bis [3-amino-4-carboxyphenyl] ] Hexafluoropropane, carboxydiphenylalkanes such as carboxydiphenylmethane such as 4,4'-diamino-2,2 ', 5,5'-tetracarboxydiphenylmethane, 3,3'-diamino-4,4'-dicarboxy Diphenyl ether, 4,4′-diamino-3,3′-dicarboxydiphenyl ether, 4,4′-diamino-2,2′-dicarboxydiphenyl ether, 4,4′-diamino-2,2 ′, 5,5 ′ -Carboxydiphenyl ether compounds such as tetracarboxydiphenyl ether, 3,3'-diamino-4,4'-dicarboxydi Enylsulfone, 4,4′-diamino-3,3′-dicarboxydiphenylsulfone, 4,4′-diamino-2,2′-dicarboxydiphenylsulfone, 4,4′-diamino-2,2 ′, 5 , 5′-tetracarboxydiphenylsulfone and other diphenylsulfone compounds, and bis [(carboxyphenyl) phenyl] alkane compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] propane, Bis [(carboxyphenoxy) phenyl] sulfone compounds such as 2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone, etc., and these may be used alone or in appropriate combination. Can do.

In the present invention, it is necessary to use a carboxyl group-containing diamine as the diamine, but those having no carboxyl group may be used in combination. As other diamines that can be used in combination, general-purpose aliphatic diamines and aromatic diamines can be used alone or in appropriate combination. Specifically, examples of other diamines include p-phenylenediamine (PPD), 1,3-diaminobenzene, 2,4-toluenediamine, 2,5-toluenediamine, and 2,6-toluenediamine. Benzene nucleus 1 diamine, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, diaminodiphenyl ethers such as 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 3,3′-dimethyl- 4,4′-diaminobiphenyl, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-bis (trifluoromethyl) -4,4′-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 (o-tolidine), 2,2′-dimethylbenzidine (m-tolidine) ), 3,3′-dimethoxybenzidine, 2,2′-dimethoxybenzidine, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide 3,4′-diaminodiphenylsulfide, 4,4′-diaminodiphenylsulfide, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, 3,3 ′ -Diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzofe 3,3′-diamino-4,4′-dimethoxybenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 2,2-bis (3-amino Phenyl) propane, 2,2-bis (4-aminophenyl) propane, 2,2-bis (3-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 3,3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide, 4,4′-diaminodiphenyl sulfoxide, Two diamine diamines such as 3,3′-dicarboxy-4,4′-diaminodiphenylmethane, 1,3-bis (3-aminophenyl) ben 1,3-bis (4-aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (4-amino) Phenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) -4-trifluoromethylbenzene, 3 , 3′-Diamino-4- (4-phenyl) phenoxybenzophenone, 3,3′-diamino-4,4′-di (4-phenylphenoxy) benzophenone, 1,3-bis (3-aminophenyl sulfide) benzene 1,3-bis (4-aminophenyl sulfide) benzene, 1,4-bis (4-aminophenyl sulfide) benzene, 1,3-bis (3-amino) Phenylsulfone) benzene, 1,3-bis (4-aminophenylsulfone) benzene, 1,4-bis (4-aminophenylsulfone) benzene, 1,3-bis [2- (4-aminophenyl) isopropyl] benzene Three diamine diamines such as 1,4-bis [2- (3-aminophenyl) isopropyl] benzene, 1,4-bis [2- (4-aminophenyl) isopropyl] benzene, 3,3′-bis (3-aminophenoxy) biphenyl, 3,3′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, Bis [3- (3-aminophenoxy) phenyl] ether, bis [3- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, bis [3- (3-aminophenoxy) phenyl] ketone, bis [3- (4-aminophenoxy) phenyl] Ketone, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [3- (3-aminophenoxy) phenyl] sulfide, bis [3- (4 -Aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [3- (3-aminophenoxy) phenyl] sulfone, Bis [3- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminopheno Cis) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] methane, bis [3- (4-aminophenoxy) phenyl] methane, bis [ 4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 2,2-bis [3- (3-aminophenoxy) phenyl] propane, 2,2-bis [ 3- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2, 2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [3- (4-amino Phenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3- Aromatic diamines such as hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, etc. , 2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1, Aliphatic diamines such as 9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,2-diaminocyclohexane It is done.
Examples of the diamine having an ether bond include polyoxyalkylene diamines such as polyoxyethylene diamine, polyoxypropylene diamine, and polyoxybutylene diamine. Commercially available products include Jeffermin EDR-148, EDR-176, Jeffermin D-230, D-400, D-2000, D-4000, Jeffermin 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 3000, and still more preferably 400 to 2000.
Examples of the amino-modified silicone include BY16-205, FZ-3760, BY16-871, BY16-853U manufactured by Toray Dow Corning.

(Acid anhydride (a1) and acid anhydride (a2))
Examples of the acid anhydride (a1) and acid anhydride (a2) include tricarboxylic acid anhydrides having at least one of an aromatic ring and an aliphatic ring, and have an aromatic ring. Trimellitic anhydride (benzene-1,2,4-tricarboxylic acid 1,2-anhydride, TMA) and the like, and hydrogenated trimellitic anhydride (cyclohexane-1,2, 4-tricarboxylic acid-1,2-anhydride, H-TMA) and the like can be preferably mentioned. These acid anhydrides may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the present invention, it is necessary to use the tricarboxylic acid anhydride as an acid anhydride, but a carboxylic acid dianhydride may be used in combination. Examples of the carboxylic dianhydride include tetracarboxylic anhydrides such as pyromellitic dianhydride and 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride. Moreover, both terminal type carboxylic anhydride modified silicone etc. are mentioned.

(Diisocyanate compound)
As the diisocyanate compound, diisocyanates such as aromatic diisocyanates and isomers and multimers thereof, aliphatic diisocyanates, alicyclic diisocyanates and isomers thereof, and other general-purpose diisocyanates can be used. Is not to be done. These diisocyanates may be used alone or in combination.

  Specific examples of the diisocyanate include aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate (MDI), tolylene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, biphenyl diisocyanate, diphenyl sulfone diisocyanate, diphenyl ether diisocyanate, and isomers thereof. , Aliphatic diisocyanates such as multimers, hexamethylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate, xylylene diisocyanate, trimethylhexamethylene diisocyanate (TMDI), or alicyclic diisocyanates hydrogenated with the above aromatic diisocyanates And isomers, or other general-purpose diiso Aneto acids and the like.

  As described above, in addition to the imidized product and the diisocyanate compound, the reaction raw material for obtaining the polyamideimide resin further contains the same acid anhydride (a2) as used when obtaining the imidized product. May be. In this case, the content of the acid anhydride (a2) in the reaction raw material is not particularly limited. From the viewpoint of improving the balance between the alkali solubility of the polyamideimide resin and the mechanical properties of the resulting cured product, the acid in the reaction raw material relative to the amount of diamine used to obtain the imidized product in the reaction raw material. The molar ratio of the amount of anhydride (a2) 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. preferable.

  The content of the diisocyanate compound in the reaction raw material is not particularly limited. From the viewpoint of improving the balance between the alkali solubility of the polyamideimide resin and the mechanical properties of the resulting cured product, the amount of the diisocyanate compound in the reaction raw material was used to obtain an imidized product in the reaction raw material. The molar ratio with respect to the sum of the amount of diamine and the amount of acid anhydride (a2) contained in the reaction raw material as required is preferably 0.3 or more and 1.0 or less, and 0.4 or more and 0.95 or less. More preferably, it is more preferably 0.50 or more and 0.90 or less.

  In particular, by using a diamine having an ether bond and H-TMA which is an alicyclic trimellitic acid, the obtained (A) polyamideimide resin has increased alkali solubility and improved developability. Therefore, it is preferable. For the same reason, it is also preferable to use an aliphatic diisocyanate in the second-stage reaction. The imide structure has a stacking structure in which molecular chains are filled with each other, so the solubility in solvents and aqueous alkali solutions is low. However, by introducing an aliphatic chain or alicyclic structure, the stacking structure collapses and the alkali solubility is low. It is thought to increase.

  In the present invention, the (A) polyamideimide resin preferably has an aliphatic structure and an ether bond. Examples of the aliphatic structure in this case include linear hexane or cyclic cyclohexane. Moreover, it is preferable that the said ether bond is a polyether structure whose molecular weight is 200 or more. Many of the imide resins have strong alkali / solvent developability. However, by introducing an aliphatic structure or an ether bond, particularly a polyether structure, the above-mentioned (A) polyamideimide resin has a weak alkali developability and a deep solution. It can have imageability and flexibility. The aliphatic structure can be introduced by using, for example, a carboxylic acid monoanhydride having an aliphatic ring or an isocyanate having an aliphatic structure, and the ether bond is, for example, the above-described ether bond. It can introduce | transduce by using the diamine which has. As the diamine having an ether bond, a diamine having a molecular weight of 200 or more is preferable.

  In addition, the amide bond of the (A) polyamideimide resin may be obtained by reacting isocyanate and carboxylic acid, or may be caused by other reaction. The (A) polyamideimide resin may further have a bond composed of other addition and condensation.

  In the present invention, as the compounding ratio of the respective components when obtaining the (A) polyamideimide resin, the acid anhydride is preferably 2.0 to 2.4 mol, based on 1 mol of the diamine. Preferably it is 2.0-2.2 mol. Although the reaction temperature at the time of making diamine and an acid anhydride react and imidating by dehydration ring closure is not specifically limited, It is preferable to exist in the range of 140 degreeC-200 degreeC. Although the reaction temperature of the imide compound obtained by making it react with the said diamine and the said acid anhydride and a diisocyanate compound is not specifically limited, It is preferable to exist in the range of 130 to 200 degreeC.

  In order to correspond to the alkali development step, the (A) polyamideimide resin preferably has an acid value of 50 mgKOH / g or more, more preferably 50 to 200 mgKOH / g, and 70 to 130 mgKOH / g. More preferably it is. When the acid value is 50 mgKOH / g or more, the solubility in alkali is increased, the developability is improved, and further, the degree of crosslinking with the thermosetting component after light irradiation is increased, so that sufficient development contrast is obtained. be able to. On the other hand, when the acid value is 200 mgKOH / g or less, so-called heat fogging in a PEB (POST EXPOSURE BAKE) step after light irradiation described later can be suppressed, and the process margin is increased.

  The molecular weight of the (A) polyamideimide resin is preferably 10,000 or less, more preferably 1000 to 8000, and still more preferably 2000 to 6000, considering developability and cured coating film characteristics. When the molecular weight is 10,000 or less, the alkali solubility in the unexposed area 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 portion.

[(B) Photobase generator]
(B) The photobase generator is a catalyst for an addition reaction between a polyimide resin having a carboxyl group and a thermosetting component when the molecular structure is changed by light irradiation such as ultraviolet light or visible light, or when the molecule is cleaved. Is a compound that produces one or more basic substances that can function as Examples of basic substances include secondary amines and tertiary amines.

  Examples of the photobase generator include α-aminoacetophenone compounds, oxime ester compounds, acyloxyimino groups, N-formylated aromatic amino groups, N-acylated aromatic amino groups, nitrobenzyl carbamate groups, alcoholoxybenzyls. Examples thereof include compounds having a substituent such as a carbamate group. Of these, oxime ester compounds and α-aminoacetophenone compounds are preferred. As the α-aminoacetophenone compound, those having two or more nitrogen atoms are particularly preferable.

  Other photobase generators include WPBG-018 (trade name: 9-anthrylmethylN, N'-diethylcarbamate), WPBG-027 (trade name: (E) -1- [3- (2-hydroxyphenyl) -2-propenoyl piperidine), WPBG-082 (trade name: guanidinium2- (3-benzoylphenyl) propionate), WPBG-140 (trade name: 1- (anthraquinon-2-yl) ethyl imidazolecarboxylate), and the like.

  The α-aminoacetophenone compound has a benzoin ether bond in the molecule, and when irradiated with light, cleavage occurs in the molecule to produce a basic substance (amine) that exhibits a curing catalytic action. Specific examples of the α-aminoacetophenone compound include (4-morpholinobenzoyl) -1-benzyl-1-dimethylaminopropane (Irgacure 369, trade name, manufactured by BASF Japan Ltd.) and 4- (methylthiobenzoyl)- 1-methyl-1-morpholinoethane (Irgacure 907, trade name, manufactured by BASF Japan Ltd.), 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4- A commercially available compound such as morpholinyl) phenyl] -1-butanone (Irgacure 379, trade name, manufactured by BASF Japan Ltd.) or a solution thereof can be used.

  As the oxime ester compound, any compound that generates 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, and N-1919, NCI-831 manufactured by Adeka Corporation. Moreover, the compound which has two oxime ester groups in the molecule | numerator described in the patent 4344400 gazette can also be used suitably.

  In addition, JP-A-2004-359639, JP-A-2005-097141, JP-A-2005-220097, JP-A-2006-160634, JP-A-2008-094770, JP-A-2008-509967, Specific examples include carbazole oxime ester compounds described in JP-A-2009-040762 and JP-A-2011-80036.

  Such a photobase generator may be used individually by 1 type, and may be used in combination of 2 or more type. The blending amount of the photobase 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 with respect to 100 parts by mass of the thermosetting component. Part. When the blending amount of the photobase generator is 0.1 parts by mass or more, it is possible to satisfactorily obtain the development resistance contrast of the light irradiated part / non-irradiated part. Moreover, the characteristic of hardened | cured material improves that the compounding quantity of a photobase generator is 40 mass parts or less.

[(C) Thermosetting component]
(C) The thermosetting component has a functional group capable of undergoing an 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 examples thereof include an epoxy resin and a polyfunctional oxetane compound.

  The epoxy resin is a resin having an epoxy group, and any known one can be used, and a bifunctional epoxy resin having two epoxy groups in the molecule or a polyfunctional epoxy resin having many epoxy groups in the molecule. A functional epoxy resin etc. are mentioned. Further, a hydrogenated bifunctional epoxy compound may be used.

  Examples of the epoxy compound include bisphenol A type epoxy resin, brominated epoxy resin, novolac type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, and alicyclic type. Epoxy resin, trihydroxyphenylmethane type epoxy resin, bixylenol type or biphenol type epoxy resin or a mixture thereof; bisphenol S type epoxy resin, bisphenol A novolac type epoxy resin, tetraphenylolethane type epoxy resin, heterocyclic epoxy resin , Diglycidyl phthalate resin, tetraglycidyl xylenoyl ethane resin, naphthalene group-containing epoxy resin, epoxy resin having dicyclopentadiene skeleton, glycidyl methacrylate Relate copolymerization system epoxy resins, copolymerized epoxy resins of cyclohexylmaleimide and glycidyl methacrylate, and a CTBN modified epoxy resin.

  Other liquid bifunctional epoxy resins include vinylcyclohexene diepoxide, (3 ′, 4′-epoxycyclohexylmethyl) -3,4-epoxycyclohexanecarboxylate, and (3 ′, 4′-epoxy-6′-methyl). And alicyclic epoxy resins such as (cyclohexylmethyl) -3,4-epoxy-6-methylcyclohexanecarboxylate. These epoxy resins may be used individually by 1 type, and may use 2 or more types together.

  In addition, you may mix | blend well-known and usual compounds, such as a maleimide compound, a block isocyanate compound, an amino resin, a benzoxazine resin, a carbodiimide resin, a cyclocarbonate compound, an episulfide resin, as a thermosetting component (C).

  (C) As a compounding quantity of a thermosetting component, it is preferable that equivalence ratio (Thermo-reactive group, such as a carboxyl group: an epoxy group) with said (A) polyamideimide resin is 10: 1 to 1:10. By setting it as the range of such a compounding ratio, developability becomes favorable and a fine pattern can be formed easily. The equivalent ratio is more preferably 10: 2 to 2:10.

[(D) Polyimide resin]
The photosensitive thermosetting resin composition of the present invention preferably further includes (D) a polyimide resin having an imide ring and a phenolic hydroxyl group. When a phenolic hydroxyl group is present, the time until it becomes alkali resistant by an addition reaction under the same heating temperature in the heat curing reaction (PEB) step after exposure may be increased as compared with the case where it does not exist. In addition, the selection range of the heat temperature during the PEB process can be expanded. For this reason, workability | operativity and handleability of the photosensitive thermosetting resin composition are improved. In addition, it is possible to suppress the occurrence of so-called fogging in which the unexposed part becomes resistant to alkali. Such (D) polyimide resin can be synthesized by using an amine component or an isocyanate component having a phenolic hydroxyl group as a raw material.

上記式（１）で表される部分構造は、下記式（２）または（３）で表されるものであることが、さらに好ましい。

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

The partial structure represented by the above formula (1) is more preferably represented by the following formula (2) or (3).

  The (D) polyimide resin preferably further has a carboxyl group in addition to the imide ring and the 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 imide ring or a group bonded thereto, and the carboxyl group is introduced into the polyimide resin by synthesis using an amine component or an isocyanate component having a carboxyl group described later. May be.

  For the synthesis of the (D) polyimide resin, a known and commonly used technique can be used. For example, a technique of reacting a carboxylic anhydride component with one or both of an amine component and an isocyanate component is used. be able to. Imidization may be performed by thermal imidization, chemical imidization, or a combination thereof.

  As the carboxylic acid anhydride component, the carboxylic acid monoanhydrides and carboxylic dianhydrides mentioned for the (A) polyamideimide resin can be used, but the carboxylic acid anhydride components are not limited to these acid anhydrides. As long as it is a compound having an acid anhydride group and a carboxyl group that react with a group or an isocyanate group, derivatives thereof can be used. These carboxylic anhydride components may be used alone or in combination of two or more.

  Examples of the amine component having a phenolic hydroxyl group include diaminophenols such as 2,4-diaminophenol, 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3 ′. Hydroxybiphenyl compounds such as -dihydroxybiphenyl, 4,4'-diamino-2,2'-dihydroxybiphenyl, 4,4'-diamino-2,2 ', 5,5'-tetrahydroxybiphenyl, 3,3' -Diamino-4,4'-dihydroxydiphenylmethane, 4,4'-diamino-3,3'-dihydroxydiphenylmethane, 4,4'-diamino-2,2'-dihydroxydiphenylmethane, 2,2-bis [3 -Amino-4-hydroxyphenyl] propane, 2,2-bis [4-amino-3-hydroxyphenyl] pro 2,2-bis [3-amino-4-hydroxyphenyl] hexafluoropropane, hydroxydiphenylalkanes such as hydroxydiphenylmethane such as 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenylmethane 3,3′-diamino-4,4′-dihydroxydiphenyl ether, 4,4′-diamino-3,3′-dihydroxydiphenyl ether, 4,4′-diamino-2,2′-dihydroxydiphenyl ether, 4,4 Hydroxy diphenyl ether compounds such as' -diamino-2,2 ', 5,5'-tetrahydroxydiphenyl ether, 3,3'-diamino-4,4'-dihydroxydiphenyl sulfone, 4,4'-diamino-3,3' -Dihydroxydiphenylsulfone, 4,4'-diamino- , 2′-dihydroxydiphenylsulfone, 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenylsulfone and the like, 2,2-bis [4- (4-amino-3- Bis [(hydroxyphenyl) phenyl] alkane compounds such as hydroxyphenoxy) phenyl] propane, bis (hydroxyphenoxy) biphenyl compounds such as 4,4′-bis (4-amino-3-hydroxyphenoxy) biphenyl, Bis [(hydroxyphenoxy) phenyl] sulfone compounds such as 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] sulfone, 4,4′-diamino-3,3′-dihydroxydiphenylmethane, Such as 4,4′-diamino-2,2′-dihydroxydiphenylmethane Bis (hydroxyphenoxy) biphenyl compounds such as ruboxidiphenylalkanes, 4,4′-diamino-2,2′-dihydroxydiphenylmethane, 4,4′-bis (4-amino-3-hydroxyphenoxy) biphenyl, Examples thereof include bis (hydroxyphenoxy) benzene compounds such as 1,3-bis (3-amino-4-hydroxyphenoxy) benzene and 1,3-bis (4-amino-3-hydroxyphenoxy) benzene. These amine components may be used alone or in combination.

  As an isocyanate component, the diisocyanate mentioned about the said (A) polyamideimide resin can be used individually or in combination.

  (D) The molecular weight of the polyimide resin is preferably from 1,000 to 100,000, more preferably from 2,000 to 50,000, considering the developability after exposure / PEB, development resistance and cured coating properties. More preferred.

A thermosetting catalyst can be blended with the photosensitive thermosetting resin composition of the present invention. The thermosetting catalyst is used to further improve the thermosetting characteristics of the thermosetting component (C), for example, amine compounds such as dicyandiamide and aromatic amines, imidazoles, phosphorus compounds, acid anhydrides, and bicyclic amidines. A compound etc. can be used. Specifically, imidazole, 1-benzyl-2-phenylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2 -Imidazoles such as phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy- Amine compounds such as N, N-dimethylbenzylamine and 4-methyl-N, N-dimethylbenzylamine, phosphorus compounds such as triphenylphosphine, and the like can be used. More specifically, as imidazole compounds, 1B2PZ, 2E4MZ, 2MZ-A, 2MZ-OK, 2PHZ, 2P4MHZ (manufactured by Shikoku Kasei Kogyo Co., Ltd.); (Manufactured by San Apro); DBU, DBN, U-CAT SA1 as bicyclic amidine compounds and salts thereof
02, U-CAT5002 (manufactured by Sun Apro Co., Ltd.) and the like. These may be used singly or in combination of two or more.

  For the content of the thermosetting catalyst, a normal blending ratio is sufficient. For example, 0.1 mass part to 10 mass parts is preferable with respect to 100 mass parts of the (C) thermosetting component.

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

  A coloring agent can also be mix | blended with the photosensitive thermosetting resin composition of this invention. As the colorant, conventionally known colorants such as red, blue, green, yellow, white, and black can be used, and any of pigments, dyes, and pigments may be used.

  The photosensitive thermosetting resin composition of the present invention can be blended with conventionally known polymer resins for the purpose of improving the flexibility and dryness of the touch of the resulting cured product. Examples of the polymer resin include cellulose-based, polyester-based, phenoxy-resin-based polymer, polyvinyl acetal-based, polyvinyl butyral-based, polyamide-based, polyimide-based, polyamide-imide-based binder polymer, block copolymer, and elastomer. One type of polymer resin may be used alone, or two or more types may be used in combination.

  In the photosensitive thermosetting resin composition of the present invention, an organic solvent can be used for preparing the resin composition or adjusting the viscosity 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. Such an organic solvent may be used individually by 1 type, and may be used as a 2 or more types of mixture.

  The photosensitive thermosetting resin composition of the present invention may further include a photopolymerizable monomer, a mercapto compound, an adhesion promoter (adhesion imparting agent), an antioxidant, an ultraviolet absorber, a thickener, if necessary. Known and commonly used components such as an antifoaming agent, a leveling agent, a silane coupling agent, and a rust preventive agent can be added. Among these, examples of the thickener include finely divided silica, hydrotalcite, organic bentonite, and montmorillonite, and examples of the antifoaming agent include silicone, fluorine, and polymer. In addition, it is preferable that the compounding quantity of a photopolymerizable monomer is 15 mass parts or less with respect to 100 mass parts of said (A) polyamideimide resin, It is more preferable that it is 10 mass parts or less, It is 0 mass part. Most preferably (not included).

  The cured product obtained from the photosensitive thermosetting resin composition of the present invention is excellent in flexibility and heat resistance and can be finely processed by alkali development. On the other hand, it is not necessary to partially use the alkali development type photosensitive resin composition, and it can be used for both the bent portion and the mounting portion of the flexible printed wiring board, and is used for the batch forming process of the bent portion and the mounting portion. Is preferred.

  The dry film of the present invention is characterized in that it has a resin layer comprising the above-described photosensitive thermosetting resin composition of the present invention. In forming a dry film, for example, the photosensitive thermosetting resin composition of the present invention is diluted with an organic solvent to adjust to an appropriate viscosity, and a uniform thickness is formed on the carrier film by a known method such as a comma coater. Apply. Thereafter, the resin layer can be usually formed on the carrier film by drying at a temperature of 50 to 130 ° C. for 1 to 30 minutes.

  A plastic film is used as the carrier film. Although there is no restriction | limiting in particular about the thickness of a carrier film, Generally, it selects suitably in the range of 10-150 micrometers. After forming the resin layer on the carrier film, a peelable cover film may be further laminated on the surface of the resin layer.

  Moreover, the printed wiring board of this invention has the characteristics in the point provided with the hardened | cured material formed using the photosensitive thermosetting resin composition of the said invention or the said dry film of this 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 forming the resin insulation layer of a printed wiring board using the photosensitive thermosetting resin composition of this invention, a suitable manufacturing method is as follows. That is, a step of forming a resin layer made of the photosensitive thermosetting resin composition of the present invention on a printed wiring board, a step of irradiating the resin layer with light in a pattern, a step of heating the resin layer (PEB), and The manufacturing method includes a step of alkali-developing the resin layer to form a resin insulating layer having a pattern. Further, if necessary, after the alkali development, further light irradiation or heat curing (post-cure) can be 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, (A) the carboxyl group of the polyamidoimide resin and thermosetting in the exposed part by heating due to the catalytic action of the base generated from the photobase generator (B) upon light irradiation. By addition reaction with the components, a negative pattern can be formed by alkali development.

[Resin layer forming step]
In this step, at least one resin layer made of 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 laminating method. In the case of the application method, the photosensitive thermosetting resin composition is applied onto a printed wiring board by a method such as screen printing and dried to form a resin layer. In the case of the laminating method, first, the photosensitive thermosetting resin composition is diluted with an organic solvent to have an appropriate viscosity, applied onto a carrier film, and dried to produce a dry film having a resin layer. Next, this dry film is bonded to the printed wiring board by a laminator or the like so that the resin layer is in contact with the printed wiring board, and then the carrier film is peeled off.

  Here, another layer can be interposed between the resin layer and the printed wiring board. Such other layers are preferably made of an alkali developing type photosensitive resin composition. As an alkali development type photosensitive resin composition, a well-known composition can be used, for example, the well-known composition for coverlays or a soldering resist can be used. Thus, by setting it as the laminated structure including another layer, the hardened | cured material which was further excellent in impact resistance and flexibility can be obtained.

[Light irradiation process]
In this step, the light irradiation part is cured by activating the photobase generator contained in the resin layer in a negative pattern by light irradiation. In this step, the base generated in the light irradiation part destabilizes the photobase generator, and the base is chemically proliferated, so that the resin layer can be sufficiently hardened. As the light irradiator, a direct writer, a light irradiator equipped with a metal halide lamp, or the like can be used. The patterned light irradiation mask is a negative 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 activated efficiently. As long as a laser beam in this range is used, either a gas laser or a solid laser may be used. Moreover, although the light irradiation amount changes with film thicknesses etc., it can generally be set as 100-1500 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 process, it is possible to cure to a deep part by the base generated in the light irradiation process. The heating temperature is, for example, 80 to 140 ° C. The heating time is, for example, 1 to 100 minutes. Since the curing of the photosensitive thermosetting resin composition in the present invention is, for example, a ring-opening reaction of an epoxy resin by a thermal reaction, it can suppress distortion and curing shrinkage compared to the case where curing proceeds by a photoradical reaction. it can.

[Development process]
In this step, the light irradiation part is removed by alkali development to form a negative pattern insulating film, in particular, a cover lay and a solder resist. The developing method can be a known method such as dipping. As the developer, sodium carbonate, potassium carbonate, potassium hydroxide, amines, imidazoles such as 2-methylimidazole, alkaline aqueous solutions such as tetramethylammonium hydroxide aqueous solution (TMAH), or a mixed solution thereof. Can be used. Note that the insulating film may be further irradiated with light after the development step. For example, you may heat at 150 degreeC or more.

  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 diagram of FIG. FIG. 1 shows a case where the resin layer has a laminated structure, but it may be composed of only one layer.

  In the laminating process of FIG. 1, a laminated structure composed of the resin layer 3 and the resin layer 4 is formed on the flexible printed wiring substrate 1 on which the copper circuit 2 is formed. The resin layer 3 is made of an alkali development type photosensitive resin composition containing a carboxyl group-containing resin or the like. Moreover, the resin layer 4 consists of the photosensitive thermosetting resin composition of this invention containing the said polyamidoimide resin, a photobase generator, and a thermosetting component.

  The light irradiation process of FIG. 1 activates the photobase generator contained in the photosensitive thermosetting resin composition by disposing a mask 5 on the resin layer 4 and irradiating light in a negative pattern. This is a step of curing the light irradiation part. The heating process of FIG. 1 is a process (PEB process) of curing the light irradiation part by heating the resin layer after the light irradiation process. The development process in FIG. 1 is a process in which an unirradiated portion is removed by developing with an alkaline aqueous solution, and a negative pattern layer is formed.

  In addition, the 2nd light irradiation process of FIG. 1 is a process for activating the remaining photobase generator as needed, and generating a base, and a thermosetting process is a pattern layer as needed. This is a process for sufficient heat curing.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not restrict | limited by these Examples and a comparative example.

<Synthesis Example 1: Synthesis Example of Polyamideimide Resin Solution>
3.8 g of 3,5-diaminobenzoic acid, 2,2′-bis [4- (4-aminophenoxy) in a separable three-necked flask equipped with a stirrer, nitrogen inlet tube, fractional ring, and cooling ring 6.98 g of phenyl] propane, 8.21 g of Jeffamine XTJ-542 (manufactured by Huntsman, molecular weight 10225.64) and 86.49 g of γ-butyrolactone were charged at room temperature and dissolved.

  Next, 17.84 g of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride and 2.88 g of trimellitic anhydride were charged and held at room temperature for 30 minutes. Next, 30 g of toluene was added, the temperature was raised to 160 ° C., the mixture was stirred for 3 hours while distilling off toluene and water, and then cooled to room temperature to obtain an imidized product solution.

  To the obtained imidized product solution, 9.61 g of trimellitic anhydride and 17.45 g of trimethylhexamethylene diisocyanate were charged and stirred at a temperature of 160 ° C. for 32 hours. Thus, a polyamideimide resin solution (PA-1) having a carboxyl group was obtained. The solid content of the obtained resin solution (PA-1) was 40.1% by mass, and the acid value of the solid content was 83.1 mgKOH.

<Synthesis Example 2: Synthesis of polyimide resin solution having imide ring, phenolic hydroxyl group and carboxyl group>
To a separable three-necked flask equipped with a stirrer, a nitrogen introduction tube, a fractionation ring, and a cooling ring, 22.4 g of 3,3′-diamino-4,4′-dihydroxydiphenylsulfone, 2,2′-bis [4 -(4-aminophenoxy) phenyl] propane 8.2 g, NMP 30 g, γ-butyrolactone 30 g, 4,4′-oxydiphthalic anhydride 27.9 g, trimellitic anhydride 3.8 g, The mixture was stirred at room temperature and 100 rpm for 4 hours under a nitrogen atmosphere. Next, 20 g of toluene was added and stirred for 4 hours while distilling off toluene and water at a silicon bath temperature of 180 ° C. and 150 rpm to obtain an alkali-soluble resin solution having an imide ring.
The acid value of the obtained resin (solid content) was 18 mgKOH, Mw was 10,000, and the hydroxyl group equivalent was 390.

<Preparation of photosensitive thermosetting resin composition>
In accordance with the formulation shown in Table 1 below, the materials described in Examples and Comparative Examples were respectively blended, premixed with a stirrer, and then kneaded with a three-roll mill to prepare a photosensitive thermosetting resin composition. In addition, unless otherwise indicated, the value of the compounding amount in a table | surface shows the mass part of solid content.

  A flexible printed wiring board on which a circuit having a copper thickness of 18 μm was formed was prepared, and pre-processing was performed using MEC Bright CB-801Y manufactured by MEC. Then, each photosensitive thermosetting resin composition was apply | coated to the flexible printed wiring base material which performed the pretreatment so that the film thickness after drying might be set to 25 micrometers. Then, it dried at 90 degreeC / 30 minutes with the hot-air circulation type drying furnace, and formed the film which consists of a photosensitive thermosetting resin composition.

<Alkali developability (patterning) and flexibility evaluation>
The base material provided with the coating film obtained above was irradiated with a negative pattern in an exposure amount of 500 mJ / cm ² with an HMW680GW (metal halide lamp, scattered light) manufactured by ORC. Next, heat treatment was performed at 90 ° C. for 60 minutes. Thereafter, the substrate was immersed in an aqueous solution of sodium carbonate at 30 ° C. and 1% by mass, developed for 3 minutes, and evaluated for alkali developability.

  Next, heat treatment was performed at 150 ° C./60 minutes using a hot air circulation drying oven to obtain a patterned cured coating film. The obtained cured coating film was subjected to an MIT test (R = 0.38 mm / Upex 12.5 μm base material manufactured by Ube Industries, Ltd.) to evaluate the flexibility. If it is about 120 cycles or more, the 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 μm and an opening diameter of 200 μm 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.
○: Opening shape is good ×: Opening shape is poor

注：表中の配合量は固形分（質量部）で表す。
＊１）ポリアミドイミド樹脂１，ＰＡ−１（合成例１の樹脂）
＊２）ポリアミドイミド樹脂２（イミド環およびアミド結合を有する）、ＳＯＸＲ−Ｍ，ニッポン高度紙工業（株）製，酸価無し 分子量１０７００
＊３）アルカリ現像性樹脂１、根上工業（株）製，酸価５０ｍｇＫＯＨ／ｇ ポリウレタン
＊４）アルカリ現像性樹脂２、共栄社化学（株）製，酸価４７ｍｇＫＯＨ／ｇ ポリウレタンアクリレート
＊５）アルカリ現像性樹脂３、日本化薬（株）製，酸価９８ｍｇＫＯＨ／ｇ ビスフェノールＦ型アクリレート樹脂
＊６）イミド樹脂（フェノール性水酸基およびカルボキシル基を有する）、ＰＩ−１（合成例２の樹脂）
＊７）Ｅ８２８，三菱化学（株）製，ビスフェノールＡ型エポキシ樹脂，エポキシ当量１９０ｇ／ｅｑ
＊８）ＯＸＥ０２，ＢＡＳＦジャパン（株）製，オキシム系光重合開始剤

Note: The compounding amount in the table is represented by solid content (parts by mass).
* 1) Polyamideimide resin 1, PA-1 (Resin of Synthesis Example 1)
* 2) Polyamideimide resin 2 (with imide ring and amide bond), SOXR-M, manufactured by Nippon Kogyo Paper Industries Co., Ltd., no acid value, molecular weight 10700
* 3) Alkali developable resin 1, manufactured by Negami Kogyo Co., Ltd., acid value 50 mg KOH / g polyurethane * 4) Alkali developable resin 2, manufactured by Kyoeisha Chemical Co., Ltd., acid value 47 mg KOH / g polyurethane acrylate * 5) Alkaline development Resin 3, manufactured by Nippon Kayaku Co., Ltd., acid value 98 mg KOH / g bisphenol F type acrylate resin * 6) imide resin (having phenolic hydroxyl group and carboxyl group), PI-1 (resin of Synthesis Example 2)
* 7) E828, manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent 190 g / eq
* 8) OXE02, manufactured by BASF Japan Ltd., oxime photopolymerization initiator

  As is clear from the evaluation results shown in Table 1, it was confirmed that the photosensitive thermosetting resin composition of each example was excellent in developability and resolution and had good flexibility. On the other hand, in the comparative example 1, while using the polyamideimide resin which does not have a carboxyl group and (C) thermosetting component is not mix | blended, 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 resolution are good, but the flexibility is insufficient.

DESCRIPTION OF SYMBOLS 1 Flexible printed wiring board 2 Copper circuit 3 Resin layer 4 Resin layer 5 Mask

Claims (13)

(A) reacting an imidized product obtained by reacting at least one diamine containing a carboxyl group-containing diamine with an acid anhydride (a1) containing a tricarboxylic acid anhydride and a diisocyanate compound; The resulting polyamideimide resin,
(B) a photobase generator, and
(C) A photosensitive thermosetting resin composition comprising a thermosetting component.   2. The photosensitive heat according to claim 1, wherein the acid anhydride (a1) includes one or both of trimellitic acid anhydride and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. Curable resin composition.   The photosensitive thermosetting resin composition according to claim 1, wherein the reaction raw material further contains a tricarboxylic acid anhydride (a2).   The photosensitive heat according to claim 3, wherein the acid anhydride (a2) includes one or both of trimellitic acid anhydride and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. Curable resin composition.   The photosensitive thermosetting resin composition according to claim 1, 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 (A) polyamideimide resin is hexane or cyclohexane.   The photosensitivity according to claim 5 or 6, wherein 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 an ether bond is 200 or more. Thermosetting resin composition.   Furthermore, (D) The photosensitive thermosetting resin composition as described in any one of Claims 1-7 containing the polyimide resin which has an imide ring and a phenolic hydroxyl group.   The photosensitive thermosetting resin composition according to claim 8, wherein the (D) polyimide resin further has a carboxyl group.   Said (C) thermosetting component is a cyclic ether compound, The photosensitive thermosetting resin composition as described in any one of Claims 1-9.   The photosensitive thermosetting resin composition as described in any one of Claims 1-10 used for a flexible printed wiring board.   It has a resin layer which consists of a photosensitive thermosetting resin composition as described in any one of Claims 1-11, The dry film characterized by the above-mentioned.   A printed wiring board comprising the photosensitive thermosetting resin composition according to claim 1 or a cured product formed using the dry film according to claim 12.

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