JP2011095355A - Photosensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition having high resolution and showing high flame retardancy after curing. <P>SOLUTION: The photosensitive resin composition comprises (A) a soluble polyimide having a polyoxypropylenediamine residue, (B) a chain or cyclic phosphazene compound having two or more acryloyloxy groups, methacryloyloxy groups or alkenyl groups in a molecule and having a repeating number of 1-20 as a photopolymerizable compound, and (C) a photoinitiator. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition.

  Conventionally, a coverlay film obtained by applying an adhesive to a molded body such as a polyimide film has been used as a protective film or an insulating film of a flexible printed circuit board. As a method for patterning a coverlay film, punching by punching has been generally used. However, in recent years, miniaturization of wiring and miniaturization of chip parts mounted on a flexible printed circuit board make it difficult to cope with the miniaturization by such processing. Therefore, in order to realize fine pattern processing, there is a demand for a photosensitive cover lay utilizing photographic technology.

  Acrylic resin is listed as a photosensitive material with excellent developability, but it has insufficient flame retardancy, heat resistance, and insulation properties, and protective films and insulation films for semiconductor elements, flexible wiring boards, rigid boards, integrated circuits, etc. It is not suitable for electrical and electronic applications. Therefore, a photosensitive cover lay using a polyimide resin excellent in electrical characteristics, chemical resistance, flame retardancy, and heat resistance has been studied.

  Examples of the photosensitive resin composition using a polyimide resin include (A) a polymer binder having a carboxyl group, (B) a (meth) acrylic compound, (C) a monofunctional epoxy compound, and (D) a photoreaction. A photosensitive resin composition containing an initiator (see, for example, Patent Document 1), (A) a polyimide resin having a carboxyl group in the side chain, (B) a photocurable resin, (C) a photopolymerization initiator, (D 1) a photosensitive adhesive composition containing a polyfunctional epoxy compound which is liquid at room temperature and (D2) a polyfunctional epoxy compound which is solid at room temperature and has a monomer or dimer structure (for example, patents) Document 2) has been proposed. Although these materials are excellent in heat resistance and developability, the flame retardancy is still insufficient. Therefore, as a highly flame-retardant material, (A) soluble polyimide, (B) a compound having a 10% weight loss temperature of 300 ° C. or more and 500 ° C. or less and containing a phosphorus atom and a nitrogen atom in one molecule (phosphazene) Compound), (C) a photosensitive resin composition containing a (meth) acrylic compound (see, for example, Patent Document 3), a) in the molecule, vinyl group, allyl group, acryloyloxy group, methacryloyloxy group, A photosensitive resin composition (see, for example, Patent Document 4) containing a phosphazene compound having at least one polymerizable functional group selected from an acryloyl group and a methacryloyl group and b) a soluble polyimide as an essential component has been proposed.

JP 2005-055545 A JP 2008-274269 A JP 2003-177515 A JP 2003-302751 A

  However, although these materials are excellent in flame retardancy, since the alkali solubility of the phosphazene compound is low, there is a problem that the developability is low and the resolution is insufficient. Therefore, an object of the present invention is to provide a photosensitive resin composition having high resolution and high flame retardancy after curing.

  The present invention comprises (A) a soluble polyimide having a diamine residue represented by the following general formula (1), (B) a photopolymerizable compound represented by the following general formula (2), and (C) a photopolymerization initiator. It is a photosensitive resin composition characterized by containing.

  In said general formula (1), a shows the range of 1-10.

In said general formula (2), b shows the range of 1-20. R ¹ and R ² are each independently acryloyloxyphenyl group, acryloyloxyalkyl group having 4 to 20 carbon atoms, methacryloyloxyphenyl group, methacryloyloxyalkyl group having 5 to 20 carbon atoms, and 3 to 20 carbon atoms. Or an alkenylaryl group having 8 to 30 carbon atoms. When b is 2 or more, the plurality of R ¹ and R ² may be the same or different.

  According to the present invention, a photosensitive resin composition having high resolution and high flame retardancy after curing can be obtained.

  The photosensitive resin composition of the present invention comprises (A) a soluble polyimide having a diamine residue represented by the general formula (1), (B) a photopolymerizable compound represented by the general formula (2), and (C) A photopolymerization initiator is contained.

  The (A) soluble polyimide in the present invention is an amide solvent such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N-vinylpyrrolidone, N, N-diethylformamide, γ-butyrolactone, methyl monoglyme, methyl diglyme, methyl triglyme, ethyl monoglyme, ethyl diglyme, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol dimethyl ether, It refers to a polyimide that dissolves 1 g or more at 25 ° C. with respect to 100 g of any organic solvent such as ethylene glycol diethyl ether.

  The (A) soluble polyimide in the present invention has an acid anhydride residue and a diamine residue, and has a residue obtained by removing a hydrogen atom of an amino group from a diamine represented by the following general formula (1). To do. Thereby, the developability with respect to the aqueous alkali solution of the photosensitive resin composition containing the photopolymerizable compound represented by the general formula (2) having a low alkali solubility is improved, and the resolution can be increased. . Moreover, since it has a flexible structure, the curvature of a laminated body can be reduced when it uses as a protective film by reducing the elastic modulus of (A) soluble polyimide and reducing the thermal stress after hardening.

  In said general formula (1), a shows the range of 1-10.

  Examples of the diamine represented by the general formula (1) include D-230 (a = 2.3 in the general formula (1)) and D-400 (a = 5.6 in the general formula (1)) (BASF Corporation). Manufactured).

  The (A) soluble polyimide in the present invention preferably has 20 mol% or more of the diamine residues represented by the general formula (1) in the total diamine residues. By having 20 mol% or more of such diamine residues, the resolution can be further improved. In addition, the flexible structure can further reduce the warpage of the stacked body when used as a protective film. From the viewpoint of further reducing the warp of the laminate, 30 mol% or more is more preferable. On the other hand, 70 mol% or less is preferable from the viewpoint of chemical resistance after curing.

  The (A) soluble polyimide in the present invention preferably further has a residue obtained by removing a hydrogen atom of an amino group from a diamine represented by the following chemical formula (4). By having such a diamine residue, the solubility of (A) soluble polyimide in an organic solvent is improved. As a result, the hydrophilicity is improved by reducing the intermolecular force of the soluble polyimide, so that the developability with respect to the alkaline aqueous solution can be further improved and the resolution can be further improved. Further, since flexibility is imparted to the polyimide skeleton by the siloxane bond, it is expected to improve the adhesion to the substrate when used as a protective film.

  In the soluble polyimide (A) in the present invention, the content of the diamine residue represented by the chemical formula (4) is preferably 5 mol% or more in the total diamine residues. By having 5 mol% or more of such diamine residues, flexibility is imparted to (A) the soluble polyimide, and the warpage of the laminate after curing can be reduced when used as a protective film. On the other hand, 30 mol% or less is preferable, moderate hydrophobicity is imparted, the developability with respect to the alkaline aqueous solution can be further improved, and the resolution can be further increased.

  The (A) soluble polyimide in the present invention preferably has an alkali-soluble functional group for development with an aqueous alkali solution. The alkali-soluble functional group is a functional group having acidity, and specific examples include a phenolic hydroxyl group and a carboxyl group. In order to introduce these alkali-soluble groups into the (A) soluble polyimide, it is preferable to contain a diamine residue represented by the following general formula (5).

In the general formula (5), Y represents —CO—, —SO ₂ —, —O—, —S—, —CH ₂ —, —NHCO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) _2- , -COO- or a single bond is shown. D and E each independently represent a hydroxyl group or a carboxyl group.

  Examples of the diamine represented by the general formula (5) include 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, and 4,4′-diamino. Hydroxybiphenyl compounds such as -2,2'-dihydroxybiphenyl, 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] propane, 2, Hydroxydiphenylalkane compounds such as 2-bis [3-amino-4-hydroxyphenyl] hexafluoropropane 3,3′-diamino-4,4′-dihydroxydiphenyl ether, 4,4′-diamino-3,3′-dihydroxydiphenyl ether, 4,4′-diamino-2,2′-dihydroxydiphenyl ether, etc. Hydroxydiphenyl ether compounds, 3,3′-diamino-4,4′-dihydroxydiphenylsulfone, 4,4′-diamino-3,3′-dihydroxydiphenylsulfone, 4,4′-diamino-2,2 ′ -Hydroxydiphenylsulfone compounds such as dihydroxydiphenylsulfone, 3,3'-diamino-4,4'-dihydroxydiphenylthioether, 4,4'-diamino-3,3'-dihydroxydiphenylthioether, 4,4 '-Diamino-2,2'-dihydroxydiphenylthio Hydroxydiphenyl thioether compounds such as ether, 3,3′-diamino-4,4′-dihydroxydiphenyl ketone, 4,4′-diamino-3,3′-dihydroxydiphenyl ketone, 4,4′-diamino- Hydroxydiphenyl ketone compounds such as 2,2'-dihydroxydiphenyl ketone, 3,3'-diamino-4,4'-dihydroxydiphenylamide, 4,4'-diamino-3,3'-dihydroxydiphenylamide Hydroxydiphenylamide compounds such as 4,4′-diamino-2,2′-dihydroxydiphenylamide, 3,3′-diamino-4,4′-dihydroxydiphenylbenzoate, 4,4′-diamino-3 , 3′-dihydroxydiphenylbenzoate, 4,4′-diamino-2, Examples include diamines having a phenolic hydroxyl group such as hydroxydiphenyl ester compounds such as 2'-dihydroxydiphenylbenzoate, and diamines having a carboxyl group such as 3,3'-dicarboxy-4,4'-diaminodiphenylmethane. it can.

  The content of the diamine residue represented by the general formula (5) is preferably 5 mol% or more, and preferably 10 mol% or more in the total diamine residues from the viewpoint of further improving the developability with respect to the alkaline aqueous solution and further improving the resolution. Is more preferable. On the other hand, from the viewpoint of reducing film loss due to development, it is preferably at most 80 mol%, more preferably at most 50 mol%.

  The (A) soluble polyimide in the present invention may contain other diamine residues to the extent that the effects of the present invention are not impaired in addition to the above diamine residues. For example, diamines containing one benzene ring such as 1,4-diaminobenzene, 1,3-diaminobenzene, 2,4-diaminotoluene, 1,4-diamino-2,5-dihalogenobenzene, bis (4 -Aminophenyl) ether, bis (3-aminophenyl) ether, bis (4-aminophenyl) sulfone, bis (3-aminophenyl) sulfone, bis (4-aminophenyl) methane, bis (3- Aminophenyl) methane, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfide, 2,2-bis (4-aminophenyl) propane, 2,2-bis (3-aminophenyl) propane, 2 , 2-bis (4-aminophenyl) hexafluoropropane, o-dianisidine, o-tolidine, tolidinesulfonic acids and the like Diamines containing two rings, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, 1,4 -Bis (3-aminophenyl) benzene, α, α'-bis (4-aminophenyl) -1,4-diisopropylbenzene, α, α'-bis (4-aminophenyl) -1,3-diisopropylbenzene, etc. Diamines containing three benzene rings, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2, 2-bis [4- (4-aminophenoxy) phenyl] sulfone, 4,4 ′-(4-aminophenoxy) biphenyl, 9,9-bis (4-aminophenyl) fluore And residues such as diamines containing 4 or more benzene rings such as 5,10-bis (4-aminophenyl) anthracene.

  (A) The structure and content of each diamine residue in the soluble polyimide are known methods such as analysis with a Fourier transform infrared spectrophotometer, or analysis with a gas chromatograph mass spectrometer after decomposing polyimide with an acid or base. Can be obtained by analyzing the repeating unit structure of polyimide.

  Examples of the tetracarboxylic dianhydride constituting the acid anhydride residue of the soluble polyimide (A) in the present invention include, for example, pyromellitic anhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3, 3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3 ′, 4,4′-diphenylsulfonetetra Carboxylic dianhydride (DSDA), 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), 2,2′-bis [(dicarboxyphenoxy) phenyl] propane dianhydride (BSAA) Etc.

  Moreover, it is preferable that (A) at least a part of the terminal of the soluble polyimide is sealed with an aniline derivative or a dicarboxylic acid anhydride. Thereby, the weight average molecular weight of (A) soluble polyimide can be easily adjusted to an appropriate range. In addition, it is expected to suppress an increase in viscosity due to crosslinking of the terminal functional group. Examples of aniline derivatives include 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzenesulfonic acid, 3-aminobenzenesulfone. Acid, 4-aminobenzenesulfonic acid, 2-aminophenol, 3-aminophenol, 4-aminophenol, 2-aminothiophenol, 3-aminothiophenol, 4-aminothiophenol and the like are preferable. As dicarboxylic acid anhydride, maleic acid anhydride, phthalic acid anhydride, nadic acid anhydride, cyclohexane dicarboxylic acid anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, 1,2-dicarboxynaphthalene anhydride , 3-hydroxyphthalic anhydride and the like are preferable.

  The method for synthesizing the soluble polyimide (A) used in the present invention is not particularly limited, and is synthesized by a known method using diamine and tetracarboxylic dianhydride. For example, a method of reacting a tetracarboxylic dianhydride and a diamine compound (some of which may be substituted with an aniline derivative) at low temperature, a diester obtained by reaction of a tetracarboxylic dianhydride and an alcohol, and then condensation By reacting with diamine (partially substituted with aniline derivative) in the presence of an agent, reaction with tetracarboxylic dianhydride and alcohol to obtain a diester, and then converting the remaining two carboxyl groups to acid chloride And a polyimide precursor is obtained using a method of reacting with diamine (a part of which may be substituted with an aniline derivative). A polyimide can be obtained by carrying out imide ring closure of the obtained polyimide precursor using a well-known method.

  The photosensitive resin composition of the present invention contains (B) a photopolymerizable compound represented by the following general formula (2). Such a photopolymerizable compound is a linear or cyclic phosphazene compound having 1 to 20 repeating units having two or more acryloyloxy groups, methacryloyloxy groups or alkenyl groups in the molecule. By having a phosphazene group, the flame retardancy of the cured photosensitive resin composition can be dramatically improved.

  In said general formula (2), b shows the range of 1-20. The number of repetitions b is preferably 2 or more. The flame retardancy after curing can be further improved by increasing the phosphorus concentration. 3 or more is more preferable. Moreover, it is 20 or less from a viewpoint which improves the developability with respect to aqueous alkali solution, and improves the resolution more, and 10 or less is preferable.

In the general formula (2), R ¹ and R ² are each independently an acryloyloxyphenyl group, an acryloyloxyalkyl group having 4 to 20 carbon atoms, a methacryloyloxyphenyl group, and a methacryloyloxyalkyl group having 5 to 20 carbon atoms. Group, an alkenyl group having 3 to 20 carbon atoms or an alkenyl aryl group having 8 to 30 carbon atoms. In addition, the carbon number of an acryloyloxyalkyl group and a methacryloyloxyalkyl group refers to the total carbon number of an acryloyloxy group or a methacryloyloxy group and an alkyl group. When b is 2 or more, the plurality of R ¹ and R ² may be the same or different.

  Examples of the alkenyl group having 3 to 20 carbon atoms include a propenyl group, an isopropenyl group, a butenyl group, a pentynyl group, and a hexynyl group. Examples of the alkenylaryl group having 8 to 30 carbon atoms include phenylpropenyl group, phenylbutenyl group, phenylpentynyl group, tolylpropenyl group, tolylbutenyl group, and tolylpentynyl group. From the viewpoint of further improving developability for an aqueous alkali solution and further improving resolution, an acryloyloxyalkyl group having 4 to 20 carbon atoms and a methacryloyloxyalkyl group having 5 to 20 carbon atoms are preferable.

  (B) Examples of the photopolymerizable compound represented by the general formula (2) include PPZ having an acryloyloxy group (manufactured by Kyoeisha Chemical Co., Ltd.).

  In the photosensitive resin composition of the present invention, (B) the content of the photopolymerizable compound represented by the general formula (2) is (A) from the viewpoint of further improving the flame retardancy by increasing the phosphorus concentration. ) 5 parts by weight or more is preferable with respect to 100 parts by weight of the soluble polyimide. Moreover, 50 weight part or less is preferable from a viewpoint of improving the developability with respect to aqueous alkali solution, and improving the resolution more.

  Moreover, the photosensitive resin composition of this invention may contain photopolymerizable compounds other than the said (B). The photopolymerizable compound is preferably a compound having at least one unsaturated double bond in the molecule. For example, the compound which has a vinyl group and a (meth) acryloyl group is mentioned. Here, the (meth) acryloyl group is a generic name for an acryloyl group and a methacryloyl group.

  Examples of photopolymerizable compounds other than (B) include ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, Methylolpropane tri (meth) acrylate, 1,2-propylene glycol di (meth) acrylate, di (1,2-propylene glycol) di (meth) acrylate, tri (1,2-propylene glycol) di (meth) acrylate, Tetra (1,2-propylene glycol) di (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminopropyl (meth) Acrylate, urethane (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 1 , 3- (meth) acryloyloxy-2-hydroxypropane, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, 2 -Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, N-vinylpyrrolidone, 2-hydroxyethyl (meth) acryloyl phosphate, (meth) acrylamide, -Methylol (meth) acrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, ethylene glycol monoacrylate, dipropylene glycol monoacrylate, N, N-dimethylaminoethyl acrylate, epoxy-modified (meth) acrylic resin, urethane-modified ( Examples thereof include a (meth) acrylic resin and a polyester-modified (meth) acrylic resin. Two or more of these may be contained.

  Among these, polyethylene glycol diacrylate and urethane acrylate are preferable. Polyethylene glycol diacrylate can further improve developability with respect to an alkaline aqueous solution, and can further increase the resolution. Urethane acrylate can further reduce the stress after curing.

  Examples of the polyethylene glycol diacrylate include “Aronix (registered trademark)” M-245, M315, and M450 (above, trade names, manufactured by Toagosei Co., Ltd.). Examples of the urethane acrylate include CN981, CN982E75, CN982P90, CN966J75, CN9001 (trade name, manufactured by Sakai Kogyo Co., Ltd.).

  The content of the photopolymerizable compound other than the above (B) is preferably 5 parts by weight or more, more preferably 20 parts by weight or more with respect to 100 parts by weight of the soluble polyimide (A) from the viewpoint of reducing film loss due to development. . On the other hand, from the viewpoint of improving the heat resistance after curing, 150 parts by weight or less is preferable, and 100 parts by weight or less is more preferable.

  The photosensitive resin composition of the present invention contains (C) a photopolymerization initiator. (C) Examples of the photopolymerization initiator include Michler's ketone, 4,4′-bis (diethylamino) benzophenone, 4,4 ′, 4 ″ -tris (dimethylamino) triphenylmethane, 2,2′-bis (2 -Chlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-diimidazole, acetophenone, benzoin, 2-methylbenzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, methylanthraquinone, thioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, diacetylbenzyl, Dildimethyl ketal, benzyl diethyl ketal, 2 (2′-furylethylidene) -4,6-bis (trichloromethyl) -S-triazine, 2 [2 ′ (5 ″ -methylfuryl) ethylidene] -4,6-bis (Trichloromethyl) -S-triazine, 2 (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine, 2,6-di (p-azidobenzal) -4-methylcyclohexanone, 4,4 '-Diazidochalcone, di (tetraalkylammonium) -4,4'-diazidostilbene-2,2'-disulfonate, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy- Cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2 Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2- Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2, 4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propane-1-ketone, bis (n5-2, 4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -fur Enyl) titanium, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], iodonium, (4-methylphenyl) [4- (2-methylpropyl) phenyl] -Hexafluorophosphate (1-), ethyl-4-dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole- 3-yl]-, 1- (O-acetyloxime) and the like. Two or more of these may be contained. Among these, oxime compounds are preferable in terms of photosensitivity. For example, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime), 1-phenyl-1,2-propanedione- 2- (o-benzoyl) oxime, bis (α-isonitrosopropiophenone oxime) isophthal, “Optomer (registered trademark)” N1919 (trade name, manufactured by Adeka), OXE02 (trade name, manufactured by Ciba Specialty Chemicals) And NCI-831 (trade name, manufactured by Adeka) and the like, OXE-02 (manufactured by Ciba Japan), “Optomer” N1919, and NCI-831 (manufactured by Adeka) are preferable.

  In the photosensitive resin composition of the present invention, the content of the (C) photopolymerization initiator photopolymerization initiator is preferably 0.1 to 40 parts by weight with respect to 100 parts by weight of the (A) soluble polyimide. When two or more photopolymerization initiators are contained, the total amount is preferably within this range. Within the above range, the content can be appropriately selected according to the type of photopolymerization initiator to be selected.

  The photosensitive resin composition of the present invention preferably further contains (D) a thermosetting agent. Thereby, the toughness after hardening of the photosensitive resin composition can be improved, and folding resistance can be improved. (D) As a thermosetting agent, an epoxy compound, a bismaleimide compound, an isocyanate compound, a block isocyanate compound, etc. are mentioned. Among these, an epoxy compound is preferable from the viewpoint of improving toughness by a crosslinking reaction. From the viewpoint of further improving the resolution and reducing the warpage of the laminate when used as a protective film, a compound represented by the following general formula (3) is more preferable.

  In the general formula (3), n and m each independently represent an integer of 0 or more. However, 1 ≦ n + m ≦ 10. x represents an integer of 1 to 5.

The epoxy compound represented by the general formula (4) is a compound having two epoxy groups and alkylene oxide (—C _x H _2x O—) in the molecule. By having an epoxy group, the crosslinking density after hardening of the photosensitive resin composition can be improved, toughness can be improved, and folding resistance can be improved. Further, by having an alkylene oxide (-C x H _{2x O-),} with improved hydrophilicity and improved developability in an alkali aqueous solution, the resolution is further improved. The repeating number m + n of alkylene oxide is preferably 3 or more. Moreover, m + n is 10 or less, and 7 or less is preferable from a viewpoint of improving the crosslinking density after hardening more and improving folding resistance. The alkylene oxide, _- ethylene oxide represented by _{(CH 2 CH 2 O-),} (- OCH 2 CH (CH 3) -) and propylene oxide represented by _{(-CH 2 CH 2 CH 2 O-} ) And so on. As the epoxy compound represented by the general formula (3), “ADEKA RESIN (registered trademark)” EP-4000S, EP-4003S (manufactured by ADEKA Corporation), BEO-60E, BPO-20E (manufactured by Shin Nippon Rika Co., Ltd.) ) And the like. Two or more of these may be contained.

  (D) As a thermosetting agent, you may contain epoxy compounds other than the said General formula (3). For example, bisphenol A type epoxy compounds such as trade name Epicoat 828, 834, 1001, 1002, 1003, 1004, 1005, 1007, 1010, 1100L (Oka Shell Co., Ltd.), trade name Epicoat ESCN-220L, 220F, 220H , 220HH, 180H65 (Oka Shell Co., Ltd.) and other o-cresol novolak type epoxy compounds, trade names such as Epicoat 1032H60 (Oka Chemical Shell Co., Ltd.) and EPPN-502H (Nippon Kayaku Co., Ltd.) Epoxy compounds, naphthalene aralkyl novolak type epoxy compounds such as trade names ESN-375 and ESN-185 (Nippon Steel Chemical Co., Ltd.), biphenol type epoxy compounds such as trade name YX4000H (Oilized Shell Co., Ltd.), bisphenol A glycidyl ether Type epoch Shi compounds, bisphenol F glycidyl ether type epoxy compounds, novolak glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, glycidyl amine type epoxy compounds, cycloaliphatic epoxy compounds, and the like aromatic epoxy compound.

  (D) As for content of a thermosetting agent, 0.1 weight part or more is preferable with respect to 100 weight part of (A) soluble polyimide. From the viewpoint of further improving the folding resistance, 5 parts by weight or more is more preferable. Moreover, 100 weight part or less is preferable and 50 weight or less is more preferable from a viewpoint which improves the developability with respect to alkaline aqueous solution, and improves a resolution more.

  The photosensitive resin composition of this invention may contain various additives, such as a flame retardant, an antifoamer, a filler, a leveling agent, a polymerization inhibitor, as needed. Examples of the filler include inorganic fillers such as silica, talc, barium sulfate, wollastonite, and calcium carbonate, and organic polymer fillers. Specifically, SOE2, SOE3 (above, trade name, manufactured by Admatechs Co., Ltd.), HE5 (trade name, manufactured by Takehara Chemical Industry Co., Ltd.), SG-95, D-1000, D-800, D- 600 (above, trade name, manufactured by Nippon Talc Co., Ltd.), B-30, B-35, BF21, BF40 (above, trade name, manufactured by Sakai Chemical Industry Co., Ltd.). As for content of a filler, 10-40 weight part is preferable with respect to 100 weight part of (A) soluble polyimide.

  The photosensitive resin composition of the present invention preferably contains a solvent. Examples of the solvent include N-methylpyrrolidone (NMP), γ-butyrolactone (γ-BL), N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide and the like.

  The photosensitive resin composition of this invention can be obtained by mixing said (A)-(C) and another component as needed. Examples of the mixing method include a method of kneading with a general kneading device such as a three roll or bead mill device, and a method of stirring with a general stirring device.

  Next, an example is given and demonstrated about the method of forming a cured film using the photosensitive resin composition of this invention.

  First, the photosensitive resin composition is applied to the substrate surface by screen printing, curtain roll, reverse roll, spray coating, spin coating using a spinner, and the like, and dried. The thickness of the coating film is preferably 5 μm to 100 μm, more preferably 10 μm to 50 μm. As a drying method of a coating film, it is preferable to heat at the temperature of 120 degrees C or less, and it is more preferable to heat at the temperature of 50-100 degreeC. In addition, in order to dry quickly, it is preferable to blow hot air.

Next, exposure and alkali development are performed to form a pattern. For example, a negative photomask is placed on the dry coating film and irradiated with actinic rays such as ultraviolet rays, visible rays, electron beams, and laser beams. Exposure is preferably 50~1000mJ / cm ^2, more preferably 50~400mJ / cm ^2. The exposure may be performed under nitrogen and is preferably performed under reduced pressure. In addition, in order to harden a light irradiation part more, you may heat-process after exposure. Alkali development is to remove an uncured portion by bringing an alkaline solution into contact with the coating film after exposure by a method such as shower, paddle, immersion, or ultrasonic wave. It is preferable to remove unnecessary residues by rinsing the pattern formed by alkali development. Examples of the rinsing liquid include water and acidic aqueous solutions.

  As the alkaline aqueous solution, a sodium carbonate aqueous solution or a tetramethylammonium hydroxide (TMAH) aqueous solution is preferably used. The temperature of the alkaline solution is preferably 10 to 40 ° C, and more preferably 20 to 35 ° C. Further, the spray pressure of the etching solution is preferably 0.05 to 3.0 MPa, particularly preferably 0.1 to 2 MPa.

  Next, the formed pattern is cured by heat treatment. The temperature of the heat treatment is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, from the viewpoint of more efficiently proceeding curing. On the other hand, when used as a protective film of a flexible printed circuit board, from the viewpoint of suppressing oxidative deterioration of wiring, 250 ° C. or lower is preferable, and 200 ° C. or lower is more preferable. Further, the heat treatment may be performed in an inert gas atmosphere such as argon, nitrogen, helium, or the like, and oxidation deterioration due to oxygen can be suppressed.

  The photosensitive resin composition of the present invention is preferably used as a photosensitive coverlay. As an example of using the photosensitive resin composition of the present invention as a photosensitive coverlay, a laminate having a protective film formed by curing the photosensitive resin composition of the present invention on a flexible printed board will be described. As the base material of the flexible printed board, a polyimide film on which a metal wiring pattern such as copper is formed is generally used. As for the thickness of a metal wiring pattern, 9-18 micrometers is common. The thickness of the protective film is generally not less than the thickness of the wiring pattern of the flexible printed board and not more than twice the thickness of the wiring pattern, preferably 10 to 20 μm.

  Next, an example is given and demonstrated about the manufacturing method of the laminated body of this invention. First, the photosensitive resin composition is applied on a flexible printed board and dried. The coating method is preferably a screen printing method. Next, it exposes through the mask of a predetermined pattern. An ultrahigh pressure mercury lamp is preferably used for exposure. Furthermore, the laminated body which has a wiring protective film can be obtained by developing and hardening processing.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, the detail of the raw material shown by the abbreviation in each Example is shown below.
<Polyimide synthetic raw material>
PMDA: pyromellitic anhydride (manufactured by Daicel Chemical Industries)
OPDA: 4,4′-oxydiphthalic dianhydride (manac)
MBAA: 3,3′-dicarboxy-4,4′-diaminodiphenylmethane (manufactured by Wakayama Seika Kogyo Co., Ltd.)
D-400: polyoxypropylene diamine (manufactured by BASF, trade name “D-400” a = 5.6 in the general formula (2))
SiDA: Bis (3-aminopropyl) tetramethyldisiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.)
ABPS: 3,3′-diamino-4,4′-dihydroxydiphenyl sulfone (manufactured by AZ Electronic Materials Co., Ltd.)
3Ap: 3-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd.)
<Photopolymerizable compound>
PPZ: 2,2,4,4,6,6-hexa (2- (methacryloyloxy) -ethoxy) -1,3,5-triaza-2,4,6-triphosphorin (manufactured by Kyoeisha Chemical Co., Ltd.)
CN981: Urethane acrylate oligomer (manufactured by Sartomer Japan, Inc.)
M-245: Polyethylene glycol diacrylate (trade name “Aronix (registered trademark)” M-245, manufactured by Toagosei Co., Ltd.)
<Photopolymerization initiator>
NCI-831; photoradical polymerization initiator (manufactured by Adeka Co., Ltd., trade name "Adeka Arcles (registered trademark)" NCI-831)
<Epoxy compound>
EP-4003S: Propylene oxide modified BisA type epoxy resin (manufactured by Adeka Co., Ltd., trade name “Adeka Resin (registered trademark)” EP-4003S, m + n = 5-6 in general formula (3), x = 3)
EP-4000S: Propylene oxide-modified BisA type epoxy resin (manufactured by Adeka Co., Ltd., trade name “Adeka Resin (registered trademark)” EP-4000S, m + n = 1 to 2, x = 3 in the general formula (3))
850S: BisA type epoxy resin (manufactured by DIC Corporation, trade name “EPICLON (registered trademark)” 850S, m + n = 0 in the general formula (3))
<Thermal polymerization inhibitor>
HQME: Hydroquinone monomethyl ether <Inorganic filler>
SG-95: Talc fine particles Average particle size 2.5 μm (Nippon Talc Co., Ltd.)
<Leveling agent>
L1983: "Disparon (registered trademark)" L1983 (manufactured by Enomoto Kasei Co., Ltd.)
<Flame Retardant>
SPR-100: Cyclophosphazene oligomer flame retardant (trade name “SPR-100” manufactured by Otsuka Chemical Co., Ltd.)
<Colorant>
PB4920: Blue pigment <solvent>
γ-BL: γ-butyrolactone.

  The evaluation method in each example and comparative example is shown below.

(1) Measurement of weight average molecular weight Using a solution having a solid content concentration of 0.1% by weight in which polyimide is dissolved in NMP, a weight average molecular weight in terms of polystyrene is calculated by a GPC apparatus Waters 2690 (manufactured by Waters Co., Ltd.) having the configuration shown below. did. GPC measurement conditions were such that the moving bed was NMP in which LiCl and phosphoric acid were each dissolved at a concentration of 0.05 mol / L, and the development rate was 0.4 ml / min.
Detector: Waters 996
System controller: Waters 2690
Column oven: Waters HTR-B
Thermo Controller: Waters TCM
Column: TOSOH grand comn
Column: THSOH TSK-GEL α-4000
Column: TOSOH TSK-GEL α-2500.

(2) Imidization rate measurement A solution having a solid concentration of 40 to 25% by weight obtained by dissolving polyimide in γ-BL was prepared and applied to a silicon wafer with a spinner so as to have a film thickness of 3 to 5 μm. Heat treated for minutes. Half of this was heat-treated at 280 ° C. for 5 minutes using a hot plate to completely close the imide group. About each of what heat-processed at 120 degreeC and 280 degreeC, the FT-IR (FT-720 made from HORIBA) analysis was performed, and the imidation ratio was computed by the difference of the peak of 1366cm < ^-1 > in which absorption derived from an imide group appears.

(3) Preparation of cured film Screen printing machine MEC-2400 (manufactured by Mitani Electronics Co., Ltd.), SUS 200 mesh, emulsion thickness 20 μm, 50 mm × 50 mm screen plate, 15 μm thick copper foil (NA- The photosensitive resin composition was applied onto VLP (made by Mitsui Kinzoku) so that the film thickness after drying was 20 μm. Subsequently, heat treatment was performed at 100 ° C. for 30 minutes using a hot air oven INH-21CD (manufactured by Koyo Thermo System Co., Ltd.). Thereafter, a negative photomask in which 50 to 50 μm vias with an area of 50 × 50 mm are arranged at a pitch of 100 μm is arranged, and an ultrahigh pressure mercury lamp exposure apparatus “PEM-6M” (manufactured by Union Optics) is used. 100 mJ / cm ² full-line exposure was performed using the i-line integrated exposure dose measurement. Thereafter, using a developing device AD-1200 (manufactured by Mikasa), development was performed for 2 minutes at a discharge pressure of 0.1 MPa using a 1 wt% aqueous sodium carbonate solution having a liquid temperature of 30 ° C. as a developing solution, and washed with water for 30 seconds. Next, using a hot air oven INH-21CD (manufactured by Koyo Thermo System Co., Ltd.), heat treatment was performed at 180 ° C. for 60 minutes to completely cure the photosensitive resin composition to obtain a cured film.

(4) Resolution evaluation The surface of the cured film obtained by the method described in (3) above is observed by magnifying it 100 times with an optical microscope, and a clear pattern is drawn on the surface. The smallest minimum via diameter was taken as the resolution. Even if a 100 μm diameter via is left undeveloped, it was marked as x.

(5) Flame retardancy evaluation The flame retardancy test was performed in accordance with UL94 V-0 and V-1 test standards. The photosensitive resin composition was applied to both sides of a 25 μm-thick polyimide film “Kapton (registered trademark)” 100EN (manufactured by Toray DuPont Co., Ltd.) so that the thickness would be 20 μm after drying, and 30 minutes at 100 ° C. Dried. Subsequently, 100 mJ / cm < ² > exposure was carried out with the ultra high pressure mercury lamp, and it heat-processed for 60 minutes at 180 degreeC using the hot air oven, and obtained the sample which laminated | stacked the cured film on both surfaces of the polyimide film. Five test pieces were prepared by cutting this sample into a length of 125 mm and a width of 13 mm. These test pieces were allowed to stand for 48 hours at a temperature of 23 ° C. and a humidity of 50% RH, and then a combustion test was performed. The upper part of the test piece was clamped at 6 mm and fixed vertically, and the flame of the burner was brought close to the lower part of the test piece for 10 seconds to make contact with the flame. After 10 seconds, the flame of the burner was moved away, and the number of seconds after which the flame or burning of the test piece disappeared was measured. When the combustion stopped within 30 seconds, the flame of the burner was further indirectly flamed for 10 seconds at the bottom of the test piece, and the burner flame was moved away, and then the number of seconds after which the flame or combustion of the test piece disappeared was measured. . (I) There is no sample that continues to burn for more than 10 seconds after the burner flame is moved away from the test piece, (ii) the total burning time for 10 flame contact with 5 test pieces does not exceed 50 seconds, ( iii) No test piece that burns to the position of the clamp, (iv) No test piece that drops burning particles, (v) No test piece that continues red heat for more than 30 seconds after the second flame contact V-0 was applied in all cases. Also, (vi) after any flame contact, there is no specimen that continues to burn for 30 seconds or more, (vii) the total combustion time for 10 flames for 5 specimens does not exceed 250 seconds, iii) no test piece that burns to the position of the clamp, (iv) no test piece that drops burning particles, (viii) no test piece that continues red heat for more than 60 seconds after the second flame contact. In all cases, V-1 was set. On the other hand, when it burned for 30 seconds or more, or it burned to the position of a clamp, it was set as the rejection.

(6) Folding resistance evaluation A polyimide film “Kapton (registered trademark)” 100EN (manufactured by Toray DuPont Co., Ltd.) having a thickness of 25 μm is cut into a size of 50 mm × 50 mm, and the photosensitive resin composition is dried on this. The film was applied to a thickness of 20 μm and dried at 100 ° C. for 30 minutes. Subsequently, 100 mJ / cm < ² > exposure was carried out with the ultrahigh pressure mercury lamp, and it heat-processed for 60 minutes at 180 degreeC using hot air oven, and obtained the laminated body of the cured film and the polyimide film. The obtained laminate was cut into a strip having a width of 10 mm and a length of 50 mm, bent at 180 ° at a length of 25 mm, and visually observed for cracks. When bending was performed 10 times and a crack was observed, the number of bending at that time was regarded as folding resistance.

(7) Warpage Evaluation In order to modelly evaluate the warpage of the laminate of the protective film and the flexible printed board, the warpage of the laminate of the cured photosensitive resin composition and the polyimide film was evaluated. The laminate of the cured film and the polyimide film obtained by the method described in (6) above was placed on a flat place so that the top was convex, and the height of the convex part was measured. The height of the convex portion is preferably 10 mm or less, and when it is 5 mm or less, it can be evaluated that the warpage is extremely small.

(8) Solder heat resistance evaluation The cured film obtained by the method described in (3) above is allowed to stand for 24 hours in an atmosphere at a temperature of 23 ° C. and a humidity of 50% RH, and then 220 ° C., 230 ° C., 240 ° C., 250 C., 260.degree. C., 270.degree. C., 280.degree. C., 290.degree. C., and 300.degree. C. were immersed in a completely dissolved solder bath for 10 seconds. Thereafter, the sample pulled up was visually observed. The lowest temperature when cracking, peeling, and swelling occurred was defined as the solder heat resistance temperature.

Synthesis example 1
In a 500 ml four-necked flask under a dry nitrogen stream, 10.74 g (25.0 mol%) of MBAA, 32.63 g (50.0 mol%) of D-400, 5.59 g (15.0 mol%) of SiDA, 86.3 g of γ-BL was charged, stirred at 60 ° C. in an oil bath, and 3.27 g (20.0 mol%) of 3Ap was added as an end-capping agent and dissolved. When the solution became uniform, 29.4 g (90.0 mol%) of PMDA and 4.65 g (10.0 mol%) of ODPA were added and reacted for 1 hour. Thereafter, the temperature of the oil bath was raised to 170 to 180 ° C., and the reaction was carried out for 2 hours while removing distilled water. Thereafter, it was allowed to cool to 25 ° C. to obtain a polyimide solution A having a solid content of 50% by weight. The obtained polyimide was soluble, the weight average molecular weight was 17,500, and the imidation ratio was 99%.

Synthesis example 2
γ-BL was changed from 86.3 g to 88.7 g, D-400 was changed from 32.63 g to 26.10 g (40.0 mol%), and SiDA was changed from 5.59 g to 9.32 g (25.0 mol%). Except for the above, a polyimide solution B having a solid content of 50% by weight was obtained in the same manner as in Synthesis Example 1. The obtained polyimide was soluble, the weight average molecular weight was 17,200, and the imidation ratio was 98%.

Synthesis example 3
A polyimide solution C having a solid content of 50% by weight was obtained in the same manner as in Synthesis Example 2 except that γ-BL was changed from 88.7 g to 83.3 g and MBAA 10.74 g was changed to ABPS 10.51 g (25.0 mol%). It was. The obtained polyimide was soluble, the weight average molecular weight was 16,400, and the imidization ratio was 100%.

Synthesis example 4
Except for changing γ-BL from 83.3 g to 78.7 g, D-400 from 26.10 g to 13.05 g (20.0 mol), and SiDA from 9.32 g to 16.77 g (45.0 mol). In the same manner as in Synthesis Example 3, a polyimide solution D having a solid content of 50% by weight was obtained. The obtained polyimide was soluble, the weight average molecular weight was 16,800, and the imidization ratio was 99%.

Synthesis example 5
In the same manner as in Synthesis Example 1 except that γ-BL was changed from 86.3 g to 90.52 g, D-400 was changed from 32.63 g to 42.41 g (65.0 mol%), and SiDA was not added. A 50 wt% polyimide solution E was obtained. The obtained polyimide was soluble, the weight average molecular weight was 14400, and the imidation ratio was 100%.

Synthesis Example 6
γ-BL was changed from 78.7 g to 72.11 g, SiDA was changed from 16.77 g to 24.23 g (65.0 mol%), and D-400 was not added. A 50 wt% polyimide solution F was obtained. The obtained polyimide was soluble, the weight average molecular weight was 16,600, and the imidization ratio was 100%.

  The compositions of Synthesis Examples 1 to 6 are shown in Table 1. In addition, each component amount (mol%) in a table | surface was computed from the addition amount of a polyimide synthesis raw material.

Example 1
To the soluble polyimide solution A8 g obtained by the method described in Synthesis Example 1, 1.3 g of CN981, 0.6 g of M-245, 0.6 g of PPZ, 0.15 g of NCI-831, and 0.004 of EP-4003S. 8 g, 0.08 g of L1983, 0.02 g of HQME, 1.4 g of SG-95 and 0.02 g of PB4920 are added, and after mixing and stirring, the photosensitive resin composition which is a viscous liquid is passed 5 times through 3 rolls. Product A was obtained.

Example 2
To the soluble polyimide solution A8 g obtained by the method described in Synthesis Example 1, 1.9 g of CN981, 0.6 g of PPZ, 0.15 g of NCI-831, 0.8 g of EP-4003, 0.08 g of L1983, 0.02 g of HQME, 1.4 g of SG-95, and 0.02 g of PB4920 were added, and after mixing and stirring, the mixture was passed through 3 rolls 5 times to obtain a photosensitive resin composition B that was a viscous liquid.

Example 3
A photosensitive resin composition C which is a viscous liquid was obtained in the same manner as in Example 1 except that the soluble polyimide solution B obtained by the method described in Synthesis Example 2 was used instead of the soluble polyimide solution A.

Example 4
A photosensitive resin composition D, which is a viscous liquid, was obtained in the same manner as in Example 1 except that the soluble polyimide solution C obtained by the method described in Synthesis Example 3 was used instead of the soluble polyimide solution A.

Example 5
A photosensitive resin composition E, which is a viscous liquid, was obtained in the same manner as in Example 1 except that the soluble polyimide solution D obtained by the method described in Synthesis Example 4 was used instead of the soluble polyimide solution A.

Example 6
A photosensitive resin composition F that is a viscous liquid was obtained in the same manner as in Example 1 except that the soluble polyimide solution E obtained by the method described in Synthesis Example 5 was used instead of the soluble polyimide solution A.

Example 7
A photosensitive resin composition G that is a viscous liquid was obtained in the same manner as in Example 1 except that 0.8 g of EP-4000S was used instead of 0.8 g of EP-4003.

Example 8
A photosensitive resin composition H, which is a viscous liquid, was obtained in the same manner as in Example 1 except that 0.8 g of 850S was used instead of 0.8 g of EP-4003.

Example 9
A photosensitive resin composition I which is a viscous liquid was obtained in the same manner as in Example 1 except that 0.8 g of EP-4003S was not used.

Example 10
A photosensitive resin composition J, which is a viscous liquid, was obtained in the same manner as in Example 1 except that M-245 was changed from 0.6 g to 0.3 g and PPZ was changed from 0.6 g to 0.9 g.

Example 11
A photosensitive resin composition K that is a viscous liquid was obtained in the same manner as in Example 1, except that CN981 was changed from 1.3 g to 1.6 g and PPZ was changed from 0.6 g to 0.3 g.

Comparative Example 1
To the soluble polyimide solution A8 g obtained by the method described in Synthesis Example 1, 1.9 g of CN981, 0.6 g of M-245, 0.15 g of NCI-831, 0.8 g of EP4003S, and 0.83 of L1983. 08 g, 0.02 g of HQME, 1.4 g of SG-95, and 0.02 g of PB4920 were added. After mixing and stirring, the mixture was passed through 3 rolls 5 times to obtain a photosensitive resin composition L which was a viscous liquid.

Comparative Example 2
A photosensitive resin composition M, which is a viscous liquid, was obtained in the same manner as in Example 1 except that the soluble polyimide solution F obtained by the method described in Synthesis Example 6 was used instead of the soluble polyimide solution A.

  Table 2 shows the composition of the photosensitive resin composition obtained in each Example and Comparative Example, and Table 3 shows the evaluation results.

Claims (5)

(A) a soluble polyimide having a diamine residue represented by the following general formula (1), (B) a photopolymerizable compound represented by the following general formula (2), and (C) a photopolymerization initiator. A photosensitive resin composition.

(In the general formula (1), a represents a range of 1 or more and 10 or less.)

(In the general formula (2), b represents a range of 1 or more and 20 or less. R ¹ and R ² each independently represents an acryloyloxyphenyl group, an acryloyloxyalkyl group having 4 to 20 carbon atoms, or a methacryloyloxyphenyl. Group, a methacryloyloxyalkyl group having 5 to 20 carbon atoms, an alkenyl group having 3 to 20 carbon atoms, or an alkenyl aryl group having 8 to 30 carbon atoms, and when b is 2 or more, a plurality of R ¹ and R ² may be the same or different. Furthermore, (D) a thermosetting agent is contained, The photosensitive resin composition of Claim 1 characterized by the above-mentioned. The said (D) thermosetting agent contains the epoxy compound shown by following General formula (3), The photosensitive resin composition of Claim 2 characterized by the above-mentioned.

(In the general formula (3), n and m each independently represent an integer of 0 or more. However, 1 ≦ m + n ≦ 10. X represents an integer of 1 to 5.) The said (A) soluble polyimide further contains 5 mol% or more and 30 mol% or less of the diamine residue shown by following Chemical formula (4) in all the diamine residues. Photosensitive resin composition.

The laminated body which has a protective film formed by hardening the photosensitive resin composition in any one of Claims 1-4 on a flexible printed circuit board.