JP4627146B2 - Photosensitive thermosetting resin composition and flexible printed wiring board - Google Patents

Description

  The present invention relates to an alkali development type photosensitive thermosetting resin composition and a flexible print which are halogen-free and have flame retardancy and do not generate harmful gases such as hydrogen bromide and dioxins during combustion. It relates to a wiring board.

  In order to protect the wiring pattern formed on the substrate by screen printing or the like from the external environment, or to prevent the solder from adhering to unnecessary parts in the soldering process performed when surface mounting electronic components on the printed wiring board In order to protect the printed wiring board, a protective film called a cover coat or a solder mask is coated on the printed wiring board.

  Epoxy resins used in thermosetting solder resists for use in such protective films are likely to burn, so in order to impart flame retardancy to the resin, halogen flame retardants and flame retardant bromine Brominated epoxy resins containing benzene have been mainly used (see, for example, Patent Document 1).

However, since decabromodiphenyl oxide, the most representative brominated flame retardant, was reported to produce toxic brominated dibenzooxide and furan during incineration, the safety of brominated flame retardants as a whole is suspected. At the time of incineration of resins using brominated flame retardants so far, toxic gases such as dioxins were generated, and the environmental burden at the time of incineration and disposal was large.
JP-A-9-54434

  Therefore, the object of the present invention is to use a flame retardant method without using a halogen-based flame retardant, and generate a fine pattern without generating harmful gases such as hydrogen bromide and dioxins that are toxic gases during combustion. Alkali-developable photosensitive thermosetting resin composition that can be formed, has a cured film rich in flexibility, and can form a film with excellent solder heat resistance, electroless gold plating resistance, chemical resistance, etc. An object of the present invention is to provide a flexible printed wiring board.

  As a result of intensive studies to solve the above-described problems, the present inventor, instead of using a halogen-containing compound to flame retardant an alkali development type photosensitive thermosetting resin composition, an organic phosphorus compound The present invention was completed by finding that the above-mentioned problems can be solved by using.

  That is, the alkali development type photosensitive thermosetting resin composition of the present invention comprises (A) a resin component having a (meth) acryloyl group and a carboxyl group in one molecule and soluble in a dilute alkaline solution; It contains (B) a thermosetting component, (C) a photopolymerization initiator, (D) an organophosphorus compound, and (E) a diluent.

  In addition, the flexible printed wiring board of the present invention is formed on the surface of a flexible printed circuit board composed of a polyimide layer and a copper layer or a polyimide layer, an adhesive layer and a copper layer, using the photosensitive thermosetting resin composition of the present invention. It is characterized by having the resin layer made.

  According to the present invention, hydrogen bromide, which is inferior in characteristics and has been a problem at the time of combustion, is generated in comparison with a photosensitive thermosetting resin composition using a conventional brominated epoxy resin and a halogen flame retardant. It is possible to provide a photosensitive thermosetting resin composition having an excellent property of not and a flexible printed wiring board using the same.

  Hereinafter, the present invention will be described in detail.

  The (A) resin component used in the present invention has a (meth) acryloyl group and a carboxyl group in one molecule, and is soluble in a dilute alkali solution. In this component, (meth) acryloyl groups in the molecule are polymerized by radicals generated from the photopolymerization initiator (C) when irradiated with active energy rays such as ultraviolet rays, and as a result, the resin composition is insolubilized. It has a function.

  As such a resin component (A), for example, an epoxy acrylate compound (for example, an epoxy acrylate oligomer) obtained by esterifying (meth) acrylic acid to an epoxy resin to modify acrylic, and further adding an acid anhydride Is mentioned.

  A general bisphenol type epoxy resin or the like can be used as an epoxy resin as a raw material of the epoxy acrylate compound. Moreover, acrylic acid, methacrylic acid, and a mixture thereof can be used for (meth) acrylic acid as a raw material. Furthermore, as the acid anhydride as a raw material, phthalic anhydride, succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, itaconic anhydride, Methyl endomethylenetetrahydrophthalic anhydride or the like can be used, and among them, succinic anhydride or phthalic anhydride is particularly preferable.

  The (A) resin component is obtained by reacting a polyol compound, a polybasic acid anhydride having two anhydrides in the molecule, and (meth) acrylic acid having one epoxy group in the molecule. It is also possible to use a carboxyl group-containing urethane compound (for example, a carboxyl group-containing urethane oligomer).

  The resin component having (meth) acryloyl group and carboxyl group in one molecule (A) of the present invention preferably has an acid value in the range of 50 to 200 mgKOH / g, and the resin component as component (A) If the acid value is less than 50 mgKOH / g, alkali solubility is lowered and alkali development becomes difficult. If it exceeds 200 mgKOH / g, film loss during development increases when used as an alkali development type photoresist. The resolution may be significantly reduced. The acid value of the resin component (A) is more preferably in the range of 80 to 150 mgKOH / g.

  As a compounding quantity of this (A) resin component, it is preferable that it is 20-70 mass% with respect to the whole photosensitive thermosetting resin composition of this invention.

  The thermosetting component (B) used in the present invention may be a thermosetting compound such as an epoxy resin, a phenol resin, a urea resin, or a melamine resin, and typically uses an epoxy resin. Examples of the epoxy resin include bisphenol A type tertiary fatty acid modified polyol epoxy resin; diglycidyl esters such as diglycidyl phthalate and diglycidyl tetrahydrophthalate, and diglycidyl amines such as diglycidyl aniline and diglycidyl toluidine. And the like. These may be used individually by 1 type, and may mix and use 2 or more types.

  In addition, phenol novolac type epoxy resin, o-cresol novolak type epoxy resin, p-cresol novolak type epoxy resin, alicyclic epoxy resin, bisphenol A type novolac epoxy resin, trishydroxyphenylmethane type epoxy resin, tetraphenylethane type epoxy Although resin etc. can be used, since there is a possibility that the cured film may be hardened if too much of these are blended, it is preferably used as a combination component.

  As a compounding quantity of this (B) thermosetting component, it is preferable that it is 1-100 mass parts with respect to 100 mass parts of (A) resin component.

Moreover, when using an epoxy resin as this (B) thermosetting component, it is preferable to use an epoxy resin hardening | curing agent together in order to further improve characteristics, such as adhesiveness, chemical resistance, and heat resistance. Specific examples of such epoxy resin curing agents, for _{example, 2MZ, 2E4MZ, C 11 Z} , C 17 Z, 2PZ, 1B2MZ, 2MZ-CN, 2E4MZ-CN, C 11 Z-CN, 2PZ-CN, 2PHZ _{-CN, 2MZ-CNS, 2E4MZ-} CNS, 2PZ-CNS, 2MZ-AZINE, 2E4MZ-AZINE, C 11 Z-AZINE, 2MA-OK, 2P4MHZ, 2PHZ, imidazole derivatives such 2P4BHZ (or, Shikoku Chemicals Corporation Manufactured, trade name); guanamines such as acetoguanamine and benzoguanamine; polyamines such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, and polybasic hydrazide; Organic acid salts and / or epoxy adducts thereof; boron trifluoride amine complexes; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xylyl-S-triazine, etc. Triazine derivatives: trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa (N-methyl) melamine, 2,4,6-tris (dimethylamino) Phenol), tetramethylguanidine, tertiary amines such as m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac; tributylphosphine, triphenylphosphine, tris-2-cyanoe Organic phosphines such as tilphosphine, phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide and hexadecyltributylphosphonium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; The polybasic acid anhydride; diphenyliodonium tetrafluoroboroate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrylium hexafluorophosphate, Irgacure-261 (trade name, manufactured by Ciba-Geigy) , Photo cation polymerization catalyst such as Optomer SP-170 (manufactured by Asahi Denka Co., Ltd., trade name); styrene-maleic anhydride resin; phenyl isocyanate and dimethylamine Molar reactant or tolylene diisocyanate, it may be used alone or two or more conventionally known curing agents or curing accelerators such as an equimolar reactant of the organic polyisocyanate and dimethyl amine such as isophorone diisocyanate.

  Here, the compounding amount of the epoxy resin curing agent is preferably 0.01 to 25 parts by mass and particularly preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of the (A) resin component.

  Examples of the (C) photopolymerization initiator used in the present invention include known and commonly used photopolymerization initiators such as active radical generators and sensitizers that generate active radicals upon irradiation with actinic rays such as ultraviolet rays.

  Examples of the active radical generator include benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1 Acetophenones such as dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, N, N-dimethylaminoacetophenone, 2- Anthraquinones such as methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone, 2,4-dimethylthioxanthone, 2 Thioxanthones such as 4-diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, 2,4-diisopropylthioxanthone, thioxanthones such as acetophenone dimethyl ketal and benzyl dimethyl ketal, ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal, Benzophenones such as benzophenone, methylbenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bisdiethylaminobenzophenone, Michler's ketone, 4-benzoyl-4′-methyldiphenyl sulfide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide Etc., and these can be used alone or in combination of two or more.

  Furthermore, this (C) photopolymerization initiator is composed of three compounds such as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine. Photosensitizers such as secondary amines can be used alone or in combination of two or more.

  A preferred combination is 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (manufactured by Ciba Geigy, trade name: Irgacure-907) and 2,4-diethylthioxanthone. (Nippon Kayaku Co., Ltd., trade name: Kayacure-DETX), 2-isopropylthioxanthone or 4-benzoyl-4'-methyldiphenyl sulfide.

  Here, the blending amount of the (C) photopolymerization initiator is preferably in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the (A) resin component.

  As the (D) organophosphorus compound used in the present invention, conventionally known organophosphorus compounds that have been used for imparting flame retardancy can be used. For example, phosphazene compounds, melamine phosphate compounds, biphenyl phosphate compounds, etc. The organic phosphorus compound can be mentioned.

（但し、式中、Ｒ^１及びＲ^２は、それぞれ水素原子又はハロゲンを含まない１価の有機基であり、ｎは３〜１０の整数である。）を挙げることができ、Ｒ^１及びＲ^２の１価の有機基としてはフェニル基、アルキル基、アミノ基、アリル基等の基が挙げられる。より好ましい化合物としては、プロポキシホスファゼンオリゴマー、フェノキシホスファゼンオリゴマー等のホスファゼンオリゴマーが挙げられる。 As phosphazene compounds, phosphazene oligomers represented by the following general formulas (I) and (II)

(Wherein, R ¹ and R ² are each a monovalent organic group not containing a hydrogen atom or halogen, and n is an integer of 3 to 10), and R ¹ and R Examples of the monovalent organic group of ² include groups such as a phenyl group, an alkyl group, an amino group, and an allyl group. More preferred compounds include phosphazene oligomers such as propoxyphosphazene oligomers and phenoxyphosphazene oligomers.

が挙げられる。これは、リン酸とメラミンが塩の状態で存在するもので、このときのｎは１〜１０であることが好ましい。 Moreover, as a melamine phosphate compound, the compound represented by the following general formula (III)

Is mentioned. In this, phosphoric acid and melamine are present in a salt state, and n at this time is preferably 1 to 10.

が挙げられる。 In addition, as the biphenyl phosphate compound, a compound represented by the following general formula (IV)

Is mentioned.

が挙げられる。この中でも、含有耐熱性、耐湿性、難燃性、耐薬品性等の観点からは、融点８０℃以上である有機リン化合物を好ましく使用することができる。 In addition, as other organic phosphorus compounds, compounds represented by the following general formula (V)

Is mentioned. Among these, an organic phosphorus compound having a melting point of 80 ° C. or higher can be preferably used from the viewpoints of contained heat resistance, moisture resistance, flame resistance, chemical resistance, and the like.

  These organophosphorus compounds can be used alone or in admixture of two or more, and the amount used is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the (A) resin component. 30 parts by mass is particularly preferable.

  As the diluent (E) used in the present invention, an organic solvent and / or a photopolymerizable monomer can be used. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, toluene, xylene, Aromatic hydrocarbons such as tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether, etc. Glycol ethers, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, alcohols such as ethanol, propanol, ethylene glycol, propylene glycol S, octane, aliphatic hydrocarbons, petroleum ether decane, may be mentioned petroleum naphtha, hydrogenated petroleum naphtha, petroleum solvents such as solvent naphtha or the like.

  On the other hand, as photopolymerization monomers, hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, glycols such as ethylene glycol, methoxytetraethylene glycol and polyethylene glycol Mono- or di (meth) acrylates, (meth) acrylamides such as N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, and aminoalkyls such as N, N-dimethylaminoethyl (meth) acrylate ( (Meth) acrylates, hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, polyhydric alcohols such as tris-hydroxyethyl isocyanurate, these Polyhydric (meth) acrylates of ethylene oxide or propylene oxide adducts, polyhydric (meth) acrylates of phenolic ethylene oxide or propylene oxide adducts such as polyethoxydi (meth) acrylate of bisphenol A, polyethoxydi (meth) acrylate , Glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, glycidyl ether (meth) acrylates such as triglycidyl isocyanurate, and ε-caprolactone modified (meth) acrylates such as caprolactone-modified tris (acryloxyethyl) isocyanurate And melamine (meth) acrylate. This (E) diluent can be used alone or as a mixture of two or more.

  The amount of the diluent (E) is preferably 1 to 100 parts by mass, particularly preferably 10 to 80 parts by mass with respect to the entire photosensitive thermosetting resin composition of the present invention.

  The purpose of use of this diluent is to dilute the resin component (A) in the case of a photopolymerizable monomer, adjust the viscosity to a state where it can be easily applied, and enhance the photopolymerizability. In this case, (A) the resin component is dissolved and diluted to adjust the viscosity to a state where it can be easily applied, and after being applied in liquid form, it is dried to form a film. Therefore, either a contact method or a non-contact exposure method in which the photomask is brought into contact with the coating film is selected according to the type of diluent used.

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

  The amount of the inorganic filler used is preferably 0 to 60% by mass and particularly preferably 5 to 40% by mass with respect to the entire photosensitive thermosetting resin composition of the present invention.

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

  Also known binder resins such as copolymers of ethylenically unsaturated compounds such as acrylate esters and polyester resins synthesized from polyhydric alcohols and polybasic acid compounds, polyester (meth) acrylates, polyurethanes ( It can be used as long as it does not affect various properties as a solder resist such as photopolymerizable oligomers such as (meth) acrylate and epoxy (meth) acrylate.

  The photosensitive thermosetting resin composition of the present invention is uniformly mixed with a three-roll mill after adding and blending other components in addition to the components (A) to (E) essential for the present invention. Can be manufactured.

  Moreover, the flexible printed wiring board of this invention is on the flexible printed wiring board which bonded the polyimide film and the copper foil to the single side | surface or both surfaces with the hot roll on the photosensitive thermosetting resin composition of this invention which is varnish shape. A flexible copper-clad laminate is manufactured by the usual method of applying and then heat-curing, and if necessary, drilling through-hole plating, or overlaying a coverlay with holes in place, and heat-press molding It can also be manufactured by the usual method of doing.

  Furthermore, a flexible printed wiring board with a reinforcing plate can be produced by an ordinary method of superimposing a reinforcing plate on the flexible printed wiring board via a thermosetting resin composition and then performing heat and pressure molding.

  In addition, the multilayer flexible printed wiring board of the present invention includes a flexible printed wiring board overlaid with a flexible copper-clad laminate, etc. via a thermosetting resin composition, heat-pressed to form a through-hole, and a through-hole. After the plating, it can be manufactured by a usual method of forming a predetermined circuit.

Next, this invention is demonstrated using an Example , a reference example, and a comparative example. In addition, it showed in Table 1 about the compounding quantity of each component used by each of an Example , a reference example, and a comparative example.

( Reference Example 1 )
80 parts by mass of Kayrad ZFR1122 (trade name, manufactured by Nippon Kayaku Co., Ltd.) as an epoxy acrylate compound, 20 parts by mass of Kayrad DPHA (trade name, manufactured by Nippon Kayaku Co., Ltd.) which is a photopolymerizable monomer as a diluent, start photopolymerization Irgacure 907 (trade name; photopolymerization initiator 1 manufactured by Ciba-Geigy Co., Ltd.) as an agent 8 parts by mass and Kayacure DETX-S (trade name; photopolymerization initiator 2 manufactured by Nippon Kayaku Co., Ltd.) 2 parts by mass, heat 20 parts by mass of biphenyl type epoxy resin (trade name: Epicoat YX4000, manufactured by Japan Epoxy Resin Co., Ltd.) as a curing component, 2 parts by mass of imidazole polymerization catalyst (trade name: 2E4MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.) as a curing agent and melamine 2 parts by mass, barium sulfate (manufactured by Sakai Chemical Industry Co., Ltd., trade name: B-30) 10 parts by mass 2 parts by mass of phthalocyanine green, 5 parts by mass of finely divided silica (manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil R972) and 5 parts by mass of phenoxyphosphazene oligomer (melting point: 110 ° C.) are mixed and kneaded by a three-roll mill. A thermosetting resin composition was produced.

( Comparative Example 3 )
Photosensitive heat is obtained by the same composition and operation as in Reference Example 1 except that 5 parts by mass of melamine pyrophosphate (manufactured by Mitsui Chemicals Fine Co., Ltd., thermal decomposition temperature: 310 ° C.) is used as the organophosphorus compound instead of phenoxyphosphazene oligomer. A curable resin composition was produced.

( Reference Example 2 )
A photosensitive heat is produced by the same composition and operation as in Reference Example 1 except that 5 parts by weight of biphenyl phosphate (trade name: HCA, melting point: 118 ° C.), instead of phenoxyphosphazene oligomer, is used as the organophosphorus compound. A curable resin composition was produced.

( Reference Example 3 )
The same composition as in Reference Example 1 except that 5 parts by mass of phosphinoylpropionic acid (manufactured by Nippon Chemical Industry Co., Ltd., trade name: MPPA, melting point: 118 ° C.) instead of the phenoxyphosphazene oligomer as the organophosphorus compound, A photosensitive thermosetting resin composition was produced by the operation.

( Example 1 )
Similar to Reference Example 1 except that 2 parts by mass of phenoxyphosphazene oligomer (melting point: 110 ° C.) and 1 part by mass of melamine pyrophosphate (manufactured by Mitsui Chemicals Fine Co., Ltd., thermal decomposition temperature: 310 ° C.) were used as the organophosphorus compound. A photosensitive thermosetting resin composition was produced by blending and operation.

( Example 2 )
1 part by mass of melamine pyrophosphate (manufactured by Mitsui Chemicals Fine Co., Ltd., thermal decomposition temperature: 310 ° C.) instead of phenoxyphosphazene oligomer as an organophosphorus compound, and biphenyl phosphate (trade name: HCA, melting point: 118 ° C.) ) A photosensitive thermosetting resin composition was produced by the same composition and operation as in Reference Example 1 except that 2 parts by mass were used.

(Comparative Example 1)
Reference Example 1 except that 20 parts by mass of a brominated epoxy resin (Dainippon Ink Co., Ltd., trade name: Epicron 1121) having no flame retardant instead of the biphenyl type epoxy resin was used without blending the phosphazene oligomer. A photosensitive thermosetting resin composition containing no organophosphorus compound was produced by the same composition and operation.

(Comparative Example 2)
The same composition and operation as in Reference Example 1 except that 5 parts by mass of tetrabromobisphenol A (manufactured by Teijin Chemicals Ltd., trade name: Fireguard), which is a brominated flame retardant, is used as the flame retardant instead of the phosphazene oligomer. Thus, a photosensitive thermosetting resin composition containing no organophosphorus compound was produced.

(Test example)
A copper-clad polyimide film in which the resin compositions obtained in Examples , Reference Examples and Comparative Examples are each formed into a thickness of 20 to 30 μm using a 150 mesh polyester screen by a screen printer. The entire surface was applied to a substrate (copper thickness 18 μm / polyimide film thickness 25 μm), and the coating film was dried with a hot air dryer at 80 ° C. for 30 minutes. Next, the negative film of the resist pattern was brought into contact with the coating film and irradiated with ultraviolet rays using an ultraviolet irradiation exposure apparatus (exposure amount 400 mJ / cm ² ). Then, 1 kgf / cm ² using 1% strength by weight sodium carbonate aqueous solution is developed by spraying for 1 minute, the unexposed portion is dissolved and removed, and further cured by heat curing at 150 ° C. for 60 minutes. A membrane was obtained.

  In such a test substrate and its production process, dry touch after drying, alkali developability, adhesion, pencil hardness, solder heat resistance, solvent resistance, acid resistance, folding resistance, electromagnetic shielding effect, Measurements and evaluations were made based on the methods and criteria shown in Table 2, and the results are shown in Table 2.

[Flame retardance test]
The test was conducted according to the UL94 flame retardant test.
[Insulation resistance]
The test was conducted according to IEC-PB112.
[Combustion gas analysis]
The sample was burned in the air at 750 ° C. for 10 minutes, and the gas generated at that time was absorbed in water as an absorbing solution and analyzed by ion chromatography, and the hydrogen bromide concentration in 100 g of the generated gas was calculated.
[Adhesion]
A peel test using a cellophane tape was performed on a test piece cross-cut to 100 mm according to JIS D 0202 on the surface of the cured film of the test substrate, and the number of peeled pieces was examined.
[Pencil hardness]
It measured according to JISK5400.

[Resolution]
The opening state was confirmed with an electron microscope.
[Solder heat resistance]
The test piece was floated on a solder bath at 260 ° C. for 1 minute, observed for the presence or absence of swelling, and evaluated according to the following criteria.
◎… No swelling, ○… Partial swelling, ×… All swelling [chemical resistance]
About each of 10% sulfuric acid, 10% sodium hydroxide aqueous solution, isopropyl alcohol, methanol, and methyl ethyl ketone, the test piece was immersed for 30 minutes at room temperature, and the external appearance was confirmed.
○: No change in appearance, ×: Change in appearance [Folding resistance]
According to JIS C 6471, the number of times until a crack of the resist was generated with an MIT folding resistance tester at R = 0.8 mm and a load of 4.9 N was measured.

  From this result, the photosensitive thermosetting resin composition of the present invention is in no way inferior to the composition using a conventional brominated epoxy resin and a halogen-based flame retardant in any characteristics, and at the time of combustion. It has been found that the hydrogen bromide, which has been regarded as a problem, does not occur.

Claims (4)

(A) a resin component having a (meth) acryloyl group and a carboxyl group in one molecule and soluble in a dilute alkali solution, (B) a thermosetting component, (C) a photopolymerization initiator, (D An alkali-developable photosensitive thermosetting resin composition containing an organic phosphorus compound and (E) a diluent,
As the (D) phosphate compound, a melamine phosphate compound represented by the following general formula (III)

And a phosphazene oligomer represented by the following general formula (I) or (II):

(Wherein, R ¹ and R ² are each a monovalent organic group not containing a hydrogen atom or halogen, and n is an integer of 3 to 10). Type photosensitive thermosetting resin composition. (A) a resin component having a (meth) acryloyl group and a carboxyl group in one molecule and soluble in a dilute alkali solution, (B) a thermosetting component, (C) a photopolymerization initiator, (D An alkali-developable photosensitive thermosetting resin composition containing an organic phosphorus compound and (E) a diluent,
As said (D) organophosphorus compound, the melamine phosphate compound represented by the following general formula (III)

And a biphenyl phosphate compound represented by the following general formula (IV):

Alkali development type photosensitive optical thermosetting resin composition you characterized in that it contains. (B) thermosetting component 1-100 parts by mass, (C) photopolymerization initiator 1-50 parts by mass, and (D) organophosphorus compound 1-50 with respect to 100 parts by mass of (A) resin component. The photosensitive thermosetting resin composition according to claim 1 , comprising 1 to 100 parts by mass of a part by weight and the diluent (E). It formed with the photosensitive thermosetting resin composition of any one of Claims 1 thru | or 3 on the surface of the flexible printed circuit board comprised from a polyimide layer and a copper layer or a polyimide layer, an adhesion layer, and a copper layer. A flexible printed wiring board comprising a resin layer.