JPH0618856B2 - Liquid photosensitive resin composition and image forming method using the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid photosensitive resin composition and an image forming method using the same, and more specifically, it is suitable as a photoresist for printed circuit boards and is suitable for exposure to ultraviolet light. Relates to a liquid photosensitive resin composition capable of both thermosetting and photocuring, which has high purity, high resolution, and excellent electrical and mechanical properties of a coating film after photocuring, and an image forming method using the same .

(Prior Art) Currently, in the field of printed circuit board manufacturing technology, VLSI
Higher density packaging requires smaller conductor spacing, which results in high sensitivity, high resolution, excellent adhesion to the substrate, and electrical and mechanical properties of the coating film after photocuring. In particular, the advent of photoresists for printed circuit boards, which are composed of an excellent photosensitive resin composition, has been demanded.

In recent years, due to problems such as working environment and water pollution, it has been desired to develop a photoresist for a printed circuit board, which is composed of a photosensitive resin composition that can be developed with an alkaline aqueous solution or water.

Conventionally, as a photoresist for a printed circuit board, a film- or sheet-shaped photoresist obtained by applying a solvent solution of a photosensitive resin composition onto a support, for example, a support such as a polyethylene terephthalate film, and drying it has been developed. There is. However, the production of these film- or sheet-shaped photoresists requires an operation of applying a solution of a photosensitive resin composition onto a support and drying the solution, which is economically expensive and a printed circuit board using a laminator. There is also the problem of poor adhesion to the printed circuit board due to the inclusion of air bubbles during thermocompression bonding to the top, and also because of the use of an organic solvent in the process of making the film or sheet, there is also a problem in terms of the working environment. Have a point.

On the other hand, liquid photosensitive resin compositions are also known as photoresists for printed circuit boards. Since this liquid photosensitive resin composition is directly applied on the printed circuit board in a liquid state immediately before use, the number of steps is small, and since it is a liquid,
An excellent image can be formed even on a substrate having severe irregularities, and is suitable as a photoresist for a printed circuit board having a narrow conductor interval, for example.

However, this liquid photosensitive resin composition also has a defect that the pattern mask becomes dirty when the liquid photosensitive resin composition is applied onto the printed circuit board and then the pattern mask is directly brought into close contact with the surface of the coating film to be exposed.

As a method for solving this pattern mask stain,
A method in which a coating film surface of a liquid photosensitive resin composition is covered with a transparent film capable of transmitting actinic rays, and then a pattern mask is brought into close contact with the transparent film to expose the liquid photosensitive resin composition. There is known a method in which after coating the composition on a printed circuit board, a chemical treatment is performed before the exposure to remove tackiness of the coating film surface, and then a pattern mask is brought into close contact with the coating film surface for exposure.

For example, JP-A-58-24144 and 59-1
No. 6396 discloses that a liquid photosensitive resin composition is applied to a transparent flexible support that transmits actinic rays to a uniform thickness, and the flexible support is immediately moved to move the liquid photosensitive resin composition. By pressing the coated surface of the resin composition toward the printed circuit board with a constant pressure, the liquid photosensitive resin composition is laminated on the printed circuit board to a constant thickness and then exposed to light to form a flexible support. There is disclosed a method for manufacturing a solder mask by peeling and developing. In this method, when the liquid photosensitive resin composition is applied on the transparent flexible support with a uniform thickness and then pressed at a constant pressure toward the printed circuit board, the printed circuit board has irregularities. As a result, air bubbles are entrapped, a large number of air bubbles are generated in the image, and this causes a problem of swelling or peeling during soldering.
Moreover, this method has the drawback that it is not economical because it requires a transparent flexible support that transmits actinic radiation in the same area as the area of the printed circuit board to be manufactured, and such a support cannot be used repeatedly.

For example, JP-A-56-99339 and JP-A-57-1
No. 17139, No. 57-173140, No. 5
In JP-A-8-25630 and JP-A-58-61110, after the coating film surface of the liquid photosensitive resin composition is cured by a chemical treatment by UV irradiation before exposure to remove tackiness, UV irradiation is further performed. A method is disclosed.
However, this method balances the exposure at the time of pre-curing and the exposure at the time of image formation by the ultraviolet irradiation time, so that the properties of the coating film after photo-curing are liable to change subtly depending on the exposure conditions, and There is a problem that a slight change causes insufficient curing at the time of pre-curing, which easily causes contamination of the pattern mask.

Further, JP-A-59-147349 discloses an image forming method in which a specific liquid photosensitive resin composition is used, pre-curing is carried out by thermal polymerization, and image formation is carried out by photo-crosslinking. However, the degree of curing in the pre-exposure curing is slightly affected by the operating conditions, and the problem of pattern mask contamination has not been completely solved.

Further, since it has to be developed with an organic solvent such as cyclohexanone, there is a problem in working environment.

(Problems to be Solved by the Invention) An object of the present invention is to solve the above-mentioned conventional technical problems and to form a photosensitive resin layer having a uniform thickness without bubbles on a printed circuit board, and By removing the tackiness of the photosensitive resin coating film surface by heating and curing the printed circuit board coated with the photosensitive resin before exposure, it is possible to expose the coating film surface and the mask in close contact with each other. It is an object of the present invention to provide a liquid photosensitive resin composition which is both photocurable and can be developed with an alkaline aqueous solution, and an image forming method using the same.

(Means for Solving Problems) The present invention includes (A) 5 to 60% by weight of a reaction product of a bisphenol epoxy acrylate having at least one carboxyl group and an acid anhydride, and (B) at least one. 5 to 40% by weight of a liquid epoxy compound having an epoxy group (excluding the component (A)), and (C) 10 to 60% by weight of a photopolymerizable compound having at least one ethylenically unsaturated double bond. , (D) 0.01 to 10% by weight of a heat-reactive catalyst capable of thermally reacting an epoxy group, and (E) a photopolymerization initiator of 0.001 to 15% by weight.

In the present invention, the liquid photosensitive resin composition is applied on a substrate and cured by heating to make it non-tacky, and then a pattern mask is brought into close contact with the cured coating film to be exposed to light and developed with an alkaline aqueous solution. The present invention relates to an image forming method.

Examples of the reaction product (component A) of the bisphenol type epoxy acrylate having at least one carboxyl group and the acid anhydride in the present invention include general formula (I) Or general formula (II) [Where X is (Q is an integer of 2 to 6), (P is an integer of 4 or 5), (R ¹ and R ² represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group), —S—, —CONR ³ — (R ³ is a hydrogen atom, having 1 to 1 carbon atoms.
6 represents an alkyl group or a phenyl group), Or (R ⁴ represents an alkyl group having 1 to 6 carbon atoms or a phenyl group), R is a hydrogen atom or a methyl group, and m is 1
A compound produced by reacting a part or all of the aliphatic hydroxyl groups of the bisphenol type epoxy acrylate represented by the integer of 300, n is an integer of 0 to 300] in the presence of an acid anhydride and a catalyst. Is mentioned.

Examples of the acid anhydride to be reacted with the bisphenol type epoxy acrylate represented by the general formula (I) or (II) include succinic anhydride, methylsuccinic anhydride, 2,3-dimethylsuccinic anhydride and 2,2-dimethylsuccinic anhydride. Acid, ethylsuccinic anhydride, dodecenylsuccinic anhydride,
Nonenylsuccinic anhydride, maleic anhydride, methylmaleic anhydride, 2,3-dimethylmaleic anhydride, 2-anhydride
Chloromaleic acid, 2,3-dichloromaleic anhydride,
Anhydride bromo maleic acid, itaconic anhydride, citraconic anhydride, cis-aconitic acid, phthalic anhydride, tetrachlorophthalic anhydride, cis - △ ⁴ - tetrahydrophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic acid, Hexahydrophthalic anhydride, trimellitic anhydride, 1,8-naphthalenedicarboxylic anhydride, etc. may be mentioned.

Examples of the catalyst used at this time include acids such as sulfuric acid, tin chloride and acetic acid chloride, sodium acetate, pyridine,
Bases such as lutidine and collidine are used.

The repeating unit of the following formula (III) in the compound represented by the general formula (I) or (II) is For example, it is produced by the reaction of a bisphenol compound and epichlorohydrin. Examples of the bisphenol compound here include 4,4'-isopropylidenediphenol, 4,4 '-(hexafluoroisopropylidene) diphenol, and bis (4-hydroxyphenyl).
Methane, 4,4'-sulfoxide, 4,4'-sulfonyldiphenol, 4,4'-thiodiphenol, p,
Examples thereof include p'-dihydroxybenzanilide, 4,4'-dihydroxybenzophenone and p, p'-dihydroxydiphenyldimethylsilane.

The compounds of the component A may be used alone or in admixture of two or more.

The blending amount of the component A in the present invention is 5 to 60% by weight, preferably 10 to 40% by weight. When the content is less than 5% by weight, the developability with an alkaline aqueous solution is lowered, and when it is more than 60% by weight, the viscosity of the liquid photosensitive resin composition is increased and the coating property is lowered.

Examples of the liquid epoxy compound (component B) having at least one epoxy group used in the present invention include n-butyl glycidyl ether, allyl glycidyl ether,
Phenyl glycidyl ether, ethylene glycol diglycidyl ether, ethylene glycol phenyl glycidyl ether, polyethylene glycol diglycidyl ether, polyethylene glycol phenyl glycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, stearyl glycidyl ether, decyl glycidyl ether, bisphenol A-diglycidyl ether, bisphenol S-diglycidyl ether, glycerol monoglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane monoglycidyl ether, trimethylolpropane triglycidyl ether,
Ethers having a glycidyl group such as diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, dibromoneopentyl glycol diglycidyl ether,
Ethers having a halogen atom and a glycidyl group such as dibromophenylglycidyl ether, amines having a glycidyl group such as N, N-diglycidylaniline, N, N-diglycidyltoluidine, and diglycidyl phthalate ester, sorbic acid Esters having a glycidyl group such as glycidyl ester, linoleic acid glycidyl ester, oleic acid glycidyl ester, benzoic acid glycidyl ester and glycidyl methacrylate,
Examples thereof include glycidyl acrylate, crotonyl glycidyl ether, and epoxy having an ethylenically unsaturated bond such as maleic acid monoalkyl ester monoglycidyl ester. These compounds may be used alone or in admixture of two or more.

The amount of component B is 5-40% by weight, preferably 10-3.
It is 0% by weight. If the amount is less than 5% by weight, the viscosity of the liquid photosensitive resin composition increases, making it difficult to form a uniform coating film on the printed circuit board. As the previous thermosetting conditions, high temperature and long time heating are required, and the practicality is lowered.

Examples of the photopolymerizable compound (component C) having at least one ethylenically unsaturated double bond used in the present invention include:
First, esters of acrylic acid or methacrylic acid of monohydric or polyhydric alcohols can be mentioned.

Examples of the monohydric alcohol in the ester of acrylic acid or methacrylic acid of monohydric or polyhydric alcohol include, for example, methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, t-butanol, cyclohexyl alcohol, benzyl alcohol, octyl alcohol, 2-ethylhexanol, lauryl alcohol, n-decanol, undecanol,
Cetyl alcohol, stearyl alcohol, methoxyethyl alcohol, ethoxyethyl alcohol, butoxyethyl alcohol, polyethylene glycol monomethyl alcohol, polyethylene glycol monoethyl alcohol, 2-hydroxyethyl alcohol, 2-hydroxypropyl alcohol, 2-hydroxy-3-chloropropane, dimethyl. Aminoethanol, diethylaminoethanol, glycidol, 2-trimethoxysilylethanol, ethylene chlorohydrin, ethylene bromohydrin, 2,3-dibromopropanol, allyl alcohol, oleyl alcohol, epoxystearyl alcohol, phenol, naphthol and the like can be mentioned. . Examples of the polyhydric alcohol include ethylene glycol, 1,
3-propanediol, 1,4-butanediol, 1,
5-pentanediol, hexanediol, heptanediol, octanediol, nonanediol, dodecanediol, neopentyl glycol, 1,10-decanediol, 2-butene-1,4-diol, 2-n-butyl-2-ethyl. Propanediol, 2-butene-1,
4-diol, cycloheptanediol, 1,4-cyclohexanedimethanol, 3-cyclohexene-1,1
-Diethanol, polyethylene glycol (diethylene glycol, triethylene glycol, etc.), polypropylene glycol (dipropylene glycol, tripropylene glycol, etc.), polystyrene oxide glycol, polytetrahydrofuran glycol, xylylene diol, bis (β-hydroxyethoxy) benzene, 3
-Chloro-1,2-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-
1,3-propanediol, 2,2-diphenyl-1,
3-propanediol, decalin diol, 1,5-dihydroxy-1,2,3,4-tetrahydronaphthalene, 2,5-dimethyl-2,5-hexanediol, 2
-Ethyl-1,3-hexanediol, 2-ethyl-2
-(Hydroxymethyl) -1,3-propanediol,
2-ethyl-2-methyl-1,3-propanediol,
3-hexene-2,5-diol, hydroxybenzyl alcohol, 2-methyl-1,4-butanediol, 2
-Methyl-2,4-pentanediol, 1-phenyl-
1,2-ethanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,3,5,6-
Tetramethyl-p-xylene-α, α'-diol,
1,1,4,4-tetraphenyl-2-butyne-1,4
-Diol, 1,1'-bi-2-naphthol, dihydroxynaphthalene, 1,1'-methylene-di-2-naphthol, biphenol, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (hydroxyphenyl) methane, catechol, resorcinol, 2-methylresorcinol, 4-chlororesorcinol, hydroquinone, phloroglucinol, pyrogallol, α- (1-aminoethyl) -p-hydroxybenzyl Alcohol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, 3-amino-1,2-propanediol, N- (3-aminopropyl ) -Diethanolamine, N, N-bis (2-hydroxyethyl) pi Rajin, 1,3-bis (hydroxymethyl) urea, 1,2-bis (4-pyridyl) -1,
2-ethanediol, Nn-butyldiethanolamine, diethanolamine, N-ethyldiethanolamine, 3-mercapto-1,2-propanediol, 3-
Piperidine-1,2-propanediol, 2- (2-pyridyl) -1,3-propanediol, α- (1-aminoethyl) -p-hydroxybenzyl alcohol, glycerin, trimethylolethane, trimethylolpropane, penta Erythritol, dipentaerythritol,
Tripentaerythritol, sorbitol, glucose, α-mannitol, butanetriol, 1,2,6
-Trihydroxyhexane, 1,2,4-benzenetriol, triethanolamine, 2,2-bis (hydroxymethyl) -2,2 ', 2 "-nitrilotriethanol and the like. Among the esters of acrylic acid or methacrylic acid of alcohol, ethylene glycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexaacrylate, Dipentaerythritol hexamethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, glycerin triac Rate, glycerin trimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolethane triacrylate, trimethylolethane trimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, sorbitol hexaacrylate, sorbitol hexamethacrylate, Sorbitol pentaacrylate, sorbitol pentamethacrylate and the like are particularly preferable.

As the C component, acrylamide or methacrylamide of monoamine or polyamine can also be used. Examples of the monoamine here include ethylamine, butylamine, amylamine, hexylamine, octylamine, cyclohexylamine, monoalkylamines such as 9-aminodecalin, allylamine, methallylamine, monoalkenylamines such as benzylamine, and aniline, toluidine, Aromatic amines such as p-aminostyrene may be mentioned. Examples of polyamines include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, hexamethylenebis (2-aminopropyl) amine, diethylenetriamine, triethylenetetraamine, polyethylenepolyamine, tris. (2-aminoethyl) amine, 4,4'-methylenebis (cyclohexylamine), N, N'-bis (2-aminoethyl) -1,
3-propanediamine, N, N'-bis (3-aminopropyl) -1,4-butanediamine, N, N'-bis (3-aminopropyl) ethylenediamine, N, N'-
Bis (3-aminopropyl) -1,3-propanediamine, 1,3-cyclohexanebis (methylamine), phenylenediamine, xylylenediamine, β- (4-aminophenyl) ethylamine, diaminotoluene, diaminoanthracene, diamino Examples thereof include naphthalene, diaminostilbene, methylenedianiline, 2,4-bis (4-aminobenzyl) aniline and aminophenyl ether.

Further, as a C component, an allyl compound such as formic acid, acetic acid, propionic acid, butyric acid, lauric acid, benzoic acid, chlorobenzoic acid, malonic acid, oxalic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid, terephthalic acid, hexa Mono- or diallyl esters of mono- or dicarboxylic acids such as hydrophthalic acid and chlorendic acid, triallyl trimellitic acid, mono- or diallyl esters of disulfonic acids such as benzenedisulfonic acid and naphthalenedisulfonic acid, diallylamine, N, N'-diallyl oxalic acid Diamide,
1,3-diallyl urea, diallyl ether and the like are also used.

As the C component, for example, polyvinyl compounds such as divinylbenzene, p-allylstyrene, p-isopropenylstyrene, divinylsulfone, ethylene glycol divinyl ether, glycerol trivinyl ether, divinyl succinate, divinyl phthalate and divinyl terephthalate, 2-hydroxy. An ester compound of acrylic acid or methacrylic acid having an ionic group such as -3-methacryloyloxypropyltrimethylammonium chloride and methacryloyloxyphenyltrimethylammonium chloride can also be used.

Further, as the C component, a commercially available photopolymerizable monomer or oligomer, for example, Aronix M5 manufactured by Toagosei Kagaku Kogyo
700, M6100, M8030, M152, M20
5, M215, M315, M325, and other acrylate-based monomers, Shin Nakamura Chemical Co., Ltd. NK ester 2G, 4
G, 9G, 14G, ABPE-4, A-TMPT, U-
4HA, CB-1, CBX-1, KAYA manufactured by Nippon Kayaku Co., Ltd.
RAD R604, DPCA-30, DPCA-66,
KAYAMER PM-1, PM-2, acrylate or methacrylate monomers such as Sannopco's Photomer 4061, 5007, Showa High Polymer Epoxy V
Epoxy acrylates such as R60, VR90 and SP1509, and spirane resins having a spiro acetal structure such as Spyrac E-4000X and U3000 manufactured by the same company and an acrylic group or a methacrylic group are also used.

These compounds may be used alone or in combination of two or more.

The amount of component C is 10 to 60% by weight, preferably 20 to
It is 50% by weight. If the blending amount is less than 10% by weight, the photocurability of the liquid photosensitive resin composition is deteriorated, and the solvent resistance and mechanical strength of the coating film after photocuring cannot be sufficiently increased. If it exceeds 5% by weight, the thermal shock resistance and solvent resistance of the coating film after photocuring will be deteriorated.

Examples of the thermoreactive catalyst (component D) capable of thermally reacting the epoxy group used in the present invention include aliphatic amines such as butylamine, amylamine and n-hexylamine, alicyclic compounds such as cyclohexylamine and aminodecalin. Amine, pyridine, lutidine, collidine, aniline,
Toluidine, N, N-dimethyl-α-naphthylamine,
Aromatic amines such as diphenylamine, aminoanthracene and triphenylamine, furfurylamine, aminopyridine, aminopicoline, aminoquinoline, aminoisoquinoline, aminodibenzofuran, aminodibenzothiophene, aminoacridine and other heterocyclic amines, ethylenediamine, diethylenetriamine, triethylene. Aliphatic polyamines such as tetraamine, tetraethylenepentamine, diethylaminopropylamine, metaxylylenediamine, polyethyleneamine, etc., aromatic polyamines such as metaphenylenediamine, triaminobenzene, diaminotoluene, diaminodiphenylmethane, diaminodiphenylsulfone, 1, 3-diaminocyclohexane, N, N-diethyl-1,4-cyclohexanediamine, isophoronedia Alicyclic diamines such as amine, N-aminoethylpiperazine, piperazine, etc., unsaturated aliphatic amines such as allylamine, diallylamine, allyldiethylamine, diaminostilbene, the amines and boron trifluoride, boron trichloride, boron tribromide Such as a complex with a boron halide, a cyano group-containing amine such as dicyandiamide, a polyamide resin, imidazoles such as imidazole, benzyltetramethylenesulfonium ion, benzylsulfonium ions such as benzyldiethylsulfonium ion, and phthalic anhydride, hexahydro Phthalic anhydride, tetrahydrophthalic anhydride, entmethylene tetrahydrophthalic anhydride, dodecyl succinic anhydride,
Examples thereof include acid anhydrides such as pyromellitic dianhydride and chlorenic anhydride. These compounds may be used alone or in admixture of two or more.

The amount of the component D is 0.01 to 10% by weight, preferably 0.05 to
It is 5% by weight. When the content is less than 0.01% by weight, the component B cannot be sufficiently thermally reacted, and a cured film having high solder heat resistance cannot be obtained. The hygroscopicity is increased and the insulation resistance of the cured film is reduced.

As the photopolymerization initiator (component E) used in the present invention,
For example, benzyl, α-diketones such as diacetyl, acyloins such as benzoin, benzoin dimethyl ether, benzoin diethyl ether, acyloin ethers such as benzoin diisopropyl ether, thioxanthone, 2,4-diethylthioxanthone, thioxanthone-1-sulfonic acid, Thioxanthones such as thioxanthone-4-sulfonic acid, benzophenones, benzophenones such as 4,4′-dimethylaminobenzophenone (Michler's ketone), acetophenone, p-dimethylaminoacetophenone, α, α′-dimethoxyacetoxyacetophenone, 2,2- Examples include acetophenones such as dimethoxy-2-phenylacetophenone and p-methoxyacetophenone, and quinones such as anthraquinone and 1,4-naphthoquinone. It is.

These photopolymerization initiators may be used alone or in combination of two or more.

The amount of component E is 0.001 to 15% by weight, preferably 0.5 to
It is 10% by weight. If the content is less than 0.001% by weight, the liquid photosensitive resin composition cannot be provided with sufficient photocurability, and if it exceeds 15% by weight, all photopolymerization initiators are reacted during photocuring. Therefore, the storage stability of the coating film after photocuring may be deteriorated, and the photopolymerization initiator may be precipitated from the liquid photosensitive resin composition before curing.

The liquid photosensitive resin composition of the present invention preferably contains a thermal addition polymerization inhibitor for preventing polymerization before heat curing. Examples of the thermal addition polymerization inhibitor include hydroquinone,
p-methoxyphenol, pt-butylcatechol,
Aromatic hydroxy compounds such as 2,6-di-t-butyl-p-cresol, β-naphthol and pyrogallol, quinones such as benzoquinone and p-toluquinone, amines such as naphthylamine, pyridine, p-toluidine and phenothiazine, Aluminum salts or ammonia salts of N-nitrosophenylhydroxylamine, floranyl, nitrobenzene and the like can be mentioned. These thermal addition polymerization inhibitors may be used alone or in admixture of two or more.

The addition amount of the thermal addition polymerization inhibitor is preferably 0.001 to 15 parts by weight, and particularly preferably 0.005 to 5 parts by weight, based on 100 parts by weight of the total amount of the above components A to E.

Furthermore, in the liquid photosensitive resin composition of the present invention, a tackifier, an adhesion aid, a dispersant, a plasticizer, an anti-sagging agent, a leveling agent, a defoaming agent, a flame retardant, a brightener, a coloring agent, etc. Auxiliary additives may be added as needed.

Examples of the tackifier or the adhesion aid include alkylphenol / formaldehyde novolac resin, polyvinyl ethyl ether, polyvinyl isobutyl ether, polyvinyl butyral, polyisobutylene, styrene-butadiene copolymer rubber, butyl rubber, vinyl chloride-vinyl acetate copolymer, and chloride. Examples thereof include rubber, acrylic adhesives, aromatic, aliphatic or alicyclic petroleum resins. These compounds may be used alone or in combination of two or more.

The compounding amount of the tackifier or the adhesion aid is preferably 0.05 based on 100 parts by weight of the total amount of the above components A to E.
To 40 parts by weight, particularly preferably 0.05 to 30 parts by weight.

Addition of a tackifier or adhesion aid enhances the adhesion of the liquid photosensitive resin composition after photo-curing to the substrate, especially when it is laminated on a copper-attached laminate or a solder-attached laminate. To be done.

The dispersant is used to improve the dispersibility, storage stability and the like of the liquid photosensitive resin composition. Plasticizer, anti-sagging agent,
The necessity of blending the leveling agent and the defoaming agent depends on the method of using the liquid photosensitive resin composition, that is, the method of forming the coating film of the liquid photosensitive resin composition, and the type and amount to be used are appropriately selected. It

In these auxiliary additives, not only a single compound exhibits one type of property (dispersibility, plasticity, anti-sagging property, leveling property or defoaming property), but also a plurality of addition effects may be exhibited. For example, the dispersant may also function as a plasticizer, a leveling agent and an antifoaming agent for the liquid photosensitive resin composition, and the dispersant, the plasticizer, the anti-sagging agent, the leveling agent and the antifoaming agent may be used after photocuring. It also has an effect on the glossiness of the liquid photosensitive resin composition, and may act as a brightener.

Examples of the dispersant include fluorine-containing polymer compounds, surfactants, modified lecithin, non-silicon long-chain carboxylic acid amine salts, organic montmorillonite, and the like.

Examples of the plasticizer include ethylene glycol diphthalate, diethylene glycol diphthalate, ethylene glycol dicapric acid ester, glycol esters such as diethylene glycol dicarpuric acid ester, dimethyl phthalate, diethylene phthalate, dibutyl phthalate, dioctyl phthalate, diaryl phthalate, butyl benzyl. Phthalates such as phthalate, phosphates such as triphenyl phosphate,
Diethyl maleate, dibutyl adipate, triethyl citrate, ethyl laurate and the like are used.

Examples of the anti-sagging agent include talc, mica silicon dioxide, titanium dioxide, calcium carbonate, magnesium carbonate, barium carbonate, and other inorganic fine powders.

Examples of the leveling agent include ANTIGEL and BLISTER FREE manufactured by Schwegmann (West Germany).
84 or the like is used.

As the defoaming agent, for example, silicone oil or the like is used. Further, for example, the dispersant BM1000, BM1100, anti-settling agent and thickening-preventing agent BM-TX, antifoaming agent BM1200, fluidity improving agent BM1000, adhesion improving agent BMS40, etc. manufactured by BM Chemie (West Germany) may be used. You can also

Examples of brighteners include Schwegmann (West Germany)
Antigen is used. The amount of these dispersants, plasticizers, anti-sagging agents, leveling agents, defoamers and brighteners is preferably 40 parts by weight or less, particularly preferably a total amount of 100 parts by weight of the liquid photosensitive resin composition. Is 20 parts by weight or less in total.

Examples of the flame retardant include inorganic flame retardants such as antimony trioxide, zirconium hydroxide, barium metaborate, magnesium hydroxide, and aluminum hydroxide, tetrabromobisphenol A, chlorinated paraffin, perchloropentacyclo. Halogen-based flame retardants such as decane, tetrabromobenzene, chlorinated diphenyl, and chlorophosphonitrile derivatives, vinylphosphonates, allylphosphonates, tris (β-chloroethyl) phosphonates, tricresylphosphonates, Phosphorus flame retardants such as ammonium phosphate are used. The amount of the flame retardant compounded is preferably 10 parts by weight or less, particularly preferably 5 parts by weight or less, based on 100 parts by weight of the total amount of the components A to E.

Examples of colorants include inorganic pigments such as titanium oxide, carbon black, iron oxide, methylene blue, crystal violet, rhodamine B, fuchsin, auramine, and the like.
Organic dyes such as azo dyes and anthraquinone dyes, phthalocyanine or azo organic pigments such as butalocyanine blue and phthalocyanine green, and dialyzin red Z, blue K and green C manufactured by Mitsubishi Kasei are used. The amount of the colorant compounded is preferably 5 parts by weight or less, particularly preferably 2 parts by weight or less, relative to 100 parts by weight of the total amount of the components A to E.

The liquid photosensitive resin composition of the present invention is usually prepared by dispersing each of the above components with a stirrer such as a super mixer to make them uniform or by dissolving them in an organic solvent and then scattering the organic solvent under reduced pressure. . At this time, a certain amount of the organic solvent may be left in the liquid photosensitive resin composition and scattered after coating. Examples of the organic solvent used in this case include acetone, ketones such as methyl ethyl ketone, methanol,
Alcohols such as ethanol and isopropyl alcohol, ethers such as tetrahydrofuran, dioxane and diethyl ether, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, and hexane,
Examples thereof include aliphatic hydrocarbons such as pentane and cyclohexane, and halogenated hydrocarbons such as methylene chloride and 1,2-dichloroethane.

When forming an image using the liquid photosensitive resin composition of the present invention thus obtained, after applying the liquid photosensitive resin composition to the substrate, heat curing to make it non-adhesive,
Then, a pattern mask is brought into close contact with the cured coating film and exposed,
Develop with an alkaline aqueous solution.

Examples of the method for applying the liquid photosensitive resin composition of the present invention onto a substrate include a spray method, a dip coating method, a brush coating method, a roller coating method, a flow coater method, a curtain coater method, and a screen printing method. Especially when coating thin film metal or printed circuit board, spray method,
Roller coating method, flow coater method, curtain coater method,
A screen printing method or the like is preferable.

The liquid photosensitive resin composition of the present invention can be cured by using either heat or light, and particularly when it is used as a photoresist, the coating film is heated and cured before being irradiated with actinic rays. The tackiness of the film surface is lost. At this time, the conditions for heat curing are, for example, 80 to 120 ° C. and 5 to 30 minutes. As a result of heat-curing in this way, it becomes non-adhesive, and it becomes possible to bring a pattern mask into close contact with the cured coating film for exposure.

The exposure apparatus used for photocuring the liquid photosensitive resin composition of the present invention is not particularly limited, but it is preferable to use an ultraviolet exposure apparatus equipped with a high pressure mercury lamp that emits ultraviolet rays in the vicinity of 300 to 400 nm.

The liquid photosensitive resin composition of the present invention can be post-baked after photo-curing, if necessary, to obtain a cured film having improved solder heat resistance.

The liquid photosensitive resin composition of the present invention is an alkaline aqueous solution as a developer, such as sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate,
An aqueous solution of 0.1 to 10% by weight of lithium carbonate, ammonia, etc. is used. However, in some cases, amines such as primary amines such as butylamine, hexylamine, benzylamine and allylamine, secondary amines such as diethylamine and benzylethylamine, tertiary amines such as triethylamine, ethanolamine, diethanolamine, triethanolamine, 2 -Hydroxyl amines such as amino-1,3-propanediol, cyclic amines such as morpholine, pyridine, piperazine and piperidine, polyamines such as hydrazine, ethylenediamine and hexamethylenediamine, sulfates, carbonates and bicarbonates of the amines. It is also possible to use basic salts such as alkali metal phosphates and pyrophosphates, and hydroxide salts such as tetramethylammonium hydroxide and choline. More alcohol,
Ketones, aromatic hydrocarbons, halogenated hydrocarbons,
Organic solvents such as halogenated aromatic hydrocarbons can also be used as a developing solution. Further, a surfactant such as polyoxyethylene glycol octylphenyl monoether or stearic acid sulfate can be added to the developer.

(Examples) Hereinafter, the present invention will be described with reference to Examples.

Example 1 200 g (0.70 hydroxyl equivalent) of bisphenol A type epoxy resin having both ends acrylated (VR90 manufactured by Showa Polymer Co., Ltd.) and 70.4 g (0.70 mol) of succinic anhydride were dissolved in 600 ml of methyl ethyl ketone dried with a molecular sieve. This solution was then added to 14.1 mmol (1.71
After the addition of γ-collidine of g), the mixture was refluxed for 20 hours to prepare a methyl ethyl ketone solution of a reaction product of a bisphenol epoxy acrylate having a carboxyl group with a concentration of 37.4% by weight and succinic anhydride.

As component A, 66.8 g of a methyl ethyl ketone solution of the reaction product having a carboxyl group obtained as described above
(Solid content 25.0 g), ethylene glycol diglycidyl ether as component B 37.5 g, bisphenol A type epoxy resin with both ends acrylated as component C (VR90 manufactured by Showa High Polymer Co., Ltd.) 37.5 g, boron trifluoride as component D /
5 g of 2,6-lutidine complex, 2.5 g of 2,2-dimethoxy-2-phenylacetophenone as an E component, and 0.05 g of an aluminum salt of N-nitrosophenylhydroxylamine as a thermal addition polymerization inhibitor were added to 100 ml of acetone.
Was mixed and dissolved in to obtain a uniform solution. Then under reduced pressure 3
Acetone and methyl ethyl ketone were scattered at 0 to 40 ° C to prepare a solventless liquid photosensitive resin composition. Using this liquid photosensitive resin composition, a coating film of the liquid photosensitive resin composition having a thickness of 70 μm was formed on a copper through-hole printed circuit board using an applicator. After heating at 100 ° C. for 5 minutes, a negative pattern mask was brought into close contact with the substrate, irradiated with ultraviolet rays having an exposure dose of 200 mJ / cm ² , and then 2% by weight.
When developed with an aqueous solution of sodium carbonate for 10 minutes,
A clear image was obtained.

When the pattern mask stain after exposure was examined, no stain was observed.

Example 2 Ethylene glycol diglycidyl ether as component B
A liquid photosensitive resin composition was prepared in the same manner as in Example 1 except that 27.5 g of ethylene glycol diglycidyl ether and 10 g of bisphenol A-diglycidyl ether were used instead of 37.5 g. Using this liquid photosensitive resin composition, a 70 μm thick coating film was formed on a copper through hole printed circuit board. After heating at 120 ° C for 5 minutes, a negative pattern mask is brought into close contact with the substrate and the exposure dose is 20
Irradiation with ultraviolet rays of 0 mJ / cm ² followed by development with a 2% by weight aqueous solution of sodium carbonate for 10 minutes gave a clear image. When the pattern mask stain after exposure was examined, no stain was observed.

Example 3 40 g of component A (as a solid component) used in Example 1, 17 g of bisphenol A-type epoxy resin having both ends acrylated as component C, and Photomer 40 manufactured by San Nopco Ltd.
61 (aliphatic bifunctional acrylate monomer) 15 g,
Bisphenol A diglycidyl ether 2 as component B
A liquid photosensitive resin composition was prepared in the same manner as in Example 1, except that 8.33 g and 2.5 g of boron trifluoride / 2,6-lutidine complex were used as the D component. Using this liquid photosensitive resin composition, a coating film having a thickness of 80 μm was formed on a copper through hole printed circuit board. After heating at 120 ° C for 15 minutes, a negative pattern mask is brought into close contact and the exposure amount is set to 2
Irradiation with ultraviolet rays of 00 mJ / cm ² followed by development with a 2% by weight aqueous sodium carbonate solution for 5 minutes gave a clear image. When the pattern mask stain after exposure was examined, no stain was observed.

Example 4 Boron trifluoride / 2,6-lutidine complex as D component 7.
A liquid photosensitive resin composition was prepared in the same manner as in Example 1 except that 5 g was used. Using this liquid photosensitive resin composition, a thickness of 70μ is formed on a copper through-hole printed circuit board.
m coating film was formed. After heating at 120 ° C. for 5 minutes to eliminate the tackiness of the coating film surface, a negative pattern mask is brought into close contact with the coating film surface, and an ultraviolet ray having an exposure dose of 200 mJ / cm ² is irradiated. A clear image was obtained by spray development using an aqueous solution of sodium carbonate for 20 minutes. When the pattern mask stain after exposure was examined, no stain was observed.

Example 5 Component A (as solid content) used in Example 1 22.67 g, C
34 g of bisphenol A type epoxy resin having both ends acrylated as components, and Photonomer 4 manufactured by San Nopco
A liquid photosensitive resin composition was prepared by treating in the same manner as in Example 3 except that 0615 15 g was used. Using this liquid photosensitive resin composition, a coating film having a thickness of 70 μm was formed on a solder through hole printed circuit board. After heating at 120 ° C. for 5 minutes, a negative type pattern mask is brought into close contact with the surface of the coating film, irradiated with ultraviolet rays having an exposure amount of 200 mJ / m ² , and then spray-developed for 20 minutes using a 2 wt% sodium carbonate aqueous solution. A clear image was obtained. When the pattern mask stain after exposure was examined, no stain was observed.

Example 6 30 g of the component A (as a solid content) used in Example 1, 20 g of a bisphenol A type epoxy resin with acrylates having both ends as the component C, and Photomer 40 manufactured by San Nopco Ltd.
61 20 g, B component as bisphenol A diglycidyl ether 30 g, D component as boron trifluoride /
2.5 g of 2,6-lutidine complex, (0.05 g of N-nitrosophenylhydroxylamine aluminum salt, 2,2-dimethoxy-2-phenylacetophenone as E component 2.
A liquid photosensitive resin composition was prepared by using 5 g and 7.7 g of cellosolve acetate and otherwise treating in the same manner as in Example 1. Using this liquid photosensitive resin composition, a coating film having a thickness of 80 μm was formed on a copper through hole printed circuit board. After heating at 120 ° C. for 20 minutes to eliminate tackiness on the surface of the coating film, a negative pattern mask is brought into close contact with the surface of the coating film and irradiated with ultraviolet rays having an exposure dose of 200 mJ / cm ² , and then 2% by weight. A clear image was obtained by spray development using an aqueous solution of sodium carbonate for 20 minutes.

Further, when the solder heat resistance was examined by heating at 130 ° C. for 30 minutes, it was dipped in a solder bath at 260 ° C. for 20 seconds and then dipped again for 20 seconds, but no change was observed on the coating film surface. It was shown that the photosensitive resin composition has the solder heat resistance required as a solder resist. The insulation resistance of the coating film after soldering is 2 × 1 under normal conditions.
The value after exposure to 0 ^{12 Ω} , 50 ° C., and 90% humidity for 120 hours was 4 × 10 ^{11 Ω} , which was excellent as a solder resist. When the pattern mask stain after exposure was examined, no stain was observed.

Example 7 Using the liquid photosensitive resin composition prepared in Example 6, a coating film having a thickness of 80 μm was formed on a copper through hole printed circuit board. Heat for 15 minutes using an infrared lamp,
The tackiness of the coating film surface was lost. The temperature of the coating film surface during heating by infrared rays increased from room temperature to 100 ° C. Thereafter, when exposure and development are performed in the same manner as in Example 6,
A clear image was obtained. When the pattern mask stain after exposure was examined, no stain was observed.

The solder heat resistance of the coating film shows 260 ° C./20 seconds (twice), the insulation resistance under normal conditions and under humidity resistance shows almost the same value as in Example 6, and the liquid photosensitive resin composition of the present invention is It was shown to be very suitable as a solder resist for printed circuit boards.

(Effect of the Invention) The liquid photosensitive resin composition of the present invention is applied to a conventional exposure machine without causing contamination of the pattern mask by coating the substrate and then heat-curing it to remove the tackiness of the coating film surface. Since it can be used for contact exposure and can be developed with an alkaline aqueous solution, there is no problem of working environment pollution due to the use of a solvent, and a photosensitive resin layer of uniform thickness without bubbles can be formed on a printed circuit board. Can be formed. Further, the liquid photosensitive resin composition of the present invention is more suitable as a resist for a printed circuit board for high-density mounting,
It is characterized by high sensitivity and resolution for UV exposure, excellent electrical and mechanical properties of the coating film after photocuring, and photocuring after heat curing.

The liquid photosensitive resin composition of the present invention is extremely excellent in adhesion to metals such as copper and solder, and resins such as epoxy resin, glass epoxy resin, and paper / phenol resin, and also serves as an electrical resist. For printed circuit boards such as copper through-hole printed circuit boards and solder through-hole printed circuit boards made of copper-loaded epoxy-glass fiber laminates, etc. because of their extremely excellent characteristics such as electrical insulation. It is suitable as a photoresist, especially as a solder resist for printed circuit boards.

Furthermore, the liquid photosensitive resin composition of the present invention can be used for photoresists for plating, photoresists for etching, various printing resin plates (relief plates, planographic plates, intaglio plates, stencil plates), optical adhesives, etc. It is also suitable for fields in which it is advantageous to use, especially for applications such as permanent insulating films for electronic parts and interlayer insulating films.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Ikeda 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd. (56) Reference JP-A-49-107333 (JP, A) JP Sho 60-121444 (JP, A) Japanese Patent Sho 60-22004 (JP, B1)

Claims (2)

[Claims] (A) 5 to 60% by weight of a reaction product of a bisphenol type epoxy acrylate having at least one carboxyl group and an acid anhydride, (B) at least 1
Liquid epoxy compound having 1 epoxy group (however, excluding the component (A)) 5 to 40% by weight, (C) 10 to 60 weight of a photopolymerizable compound having at least one ethylenically unsaturated double bond %, (D) 0.01 to 10% by weight of a heat-reactive catalyst capable of thermally reacting an epoxy group, and (E) a photopolymerization initiator of 0.001 to 15% by weight. 2. (A) 5 to 60% by weight of a reaction product of a bisphenol type epoxy acrylate having at least one carboxyl group and an acid anhydride, and (B) at least 1.
Liquid epoxy compound having 1 epoxy group (however, excluding the component (A)) 5 to 40% by weight, (C) 10 to 60 weight of a photopolymerizable compound having at least one ethylenically unsaturated double bond %, (D) 0.01 to 10% by weight of a heat-reactive catalyst capable of thermally reacting an epoxy group, and (E) a photopolymerization initiator of 0.001 to 15% by weight, a liquid photosensitive resin composition comprising: An image forming method, which comprises coating on the surface, heat-curing, exposing the cured coating film to a pattern mask, exposing, and developing with an alkaline aqueous solution.