JP2668276B2 - Photosensitive resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a photosensitive resin composition. More specifically, it can be used for forming a permanent protective mask such as a solder resist for manufacturing a printed wiring board, is highly sensitive to ultraviolet light exposure, has excellent developability with an alkaline aqueous solution, and has little change in developability with time. The present invention also relates to a photosensitive resin composition having excellent electrical properties, mechanical properties, and chemical resistance of a cured coating film.

(Prior art) Conventionally, in the printed wiring board industry, solder resist,
Resin compositions used for permanent protection masks such as resists for chemical plating are mainly composed of thermosetting resins such as epoxy resins and melamine resins, and screen printing is often used for pattern formation. Have been. The main purpose of the solder resist is to limit the soldering area at the time of soldering, prevent solder bridges and the like, prevent corrosion of conductors, and maintain electrical insulation between conductors for a long period of time.

In recent years, as high-density packaging of VLSIs and the like has progressed, the spacing between conductors has been required to be reduced, and the demand for electrical insulation between conductors has been strict. It has become. However, the screen printing method has essentially low resolution, causing phenomena such as blurring, pinholes (in the case of high-viscosity ink), bleeding, bleeding, and dripping (in the case of low-viscosity), and increasing the density of printed wiring boards. Can no longer respond to.

Therefore, a photosensitive resin composition which can form a pattern by a photographic method (an image is formed by development following image exposure), has high sensitivity, high resolution, and is excellent in electrical properties and mechanical properties of a coating film after curing. However, it is currently receiving attention.

A dry film type or liquid developable photosensitive resin composition has been developed as a permanent protective mask for a printed wiring board on which a pattern is formed by a photographic method.

As a dry film type photosensitive resin composition, for example, JP-A-57-55914 and the like, a photosensitive resin composition comprising a urethane di (meth) acrylate, a linear polymer compound and a high sensitizer, JP-A-62-247353 discloses a photosensitive resin composition comprising a (meth) acryl-modified resin of a specific novolak epoxy resin and a high sensitizer.

However, in general, in the case of a dry film type photosensitive resin composition, bubbles are easily generated at the time of thermocompression bonding, and there are concerns about heat resistance and adhesion. Therefore, in order to solve those problems, a special process such as heating and pressure bonding under reduced pressure is required as disclosed in Japanese Patent Application Laid-Open No. 52-52703, etc. However, complete heat resistance and adhesion are not guaranteed.

On the other hand, a liquid developable photosensitive resin composition has a small number of steps because it is directly applied to a printed wiring board in a liquid state immediately before use. It can form an excellent image and is suitable as, for example, a photosensitive resin composition for a permanent protection mask for a printed wiring board having a narrow conductor interval.

However, this liquid photosensitive resin composition also has a drawback that the pattern mask is stained when exposed to light by directly applying the pattern mask to the coating film surface after coating on the printed wiring board.

As a method for solving the contamination of the pattern mask, as disclosed in JP-A-57-164595, the coating film surface and the pattern mask are arranged at intervals, exposed and cured, and the uncured liquid There is a special method of removing the photosensitive resin composition. However, as a result of increasing the distance between the coating film surface and the pattern mask, there are disadvantages such as a decrease in resolution and an increase in cost due to the provision of a special device.

Further, JP-A-58-24144, JP-A-59-2049, JP-A-61-10265
2, JP-A-62-27736 discloses a method for producing a solder resist using a transparent flexible support or a pattern mask, but these methods also require a specific apparatus and are expensive. There is a problem.

Further, in the method of exposing the liquid photosensitive composition according to the resist pattern as it is without drying the liquid photosensitive composition as described above, the liquid photosensitive composition uses a liquid prepolymer containing a large number of reactive monomers, and thus is resistant to acid. Also, there is a problem that properties such as chemical resistance are inferior to those of a normal method.

Therefore, usually, after applying a liquid photosensitive resin, heat drying,
A method of forming a solder resist by bringing a pattern mask into close contact with each other and performing exposure and development is used.
As such an example, a photopolymerizable compound obtained by reacting a novolak type epoxy compound with an unsaturated monocarboxylic acid as disclosed in JP-A-62-27773 and JP-A-62-27774, etc. There is a liquid resin composition containing.

Further, in recent years, a photosensitive resin composition that can be developed with an alkaline aqueous solution or water has been desired due to problems such as work environment, air and water pollution. As an example of this, Japanese Patent Laid-Open No.
-243869, 63-258975, etc., a photopolymerizable compound obtained by reacting 1) a novolak type epoxy compound with 2) an unsaturated monocarboxylic acid and 3) a polybasic anhydride. There is a liquid resin composition containing a compound.

However, these photosensitive resin compositions are used in the synthesis of a photopolymerizable compound obtained by reacting an epoxy resin, which is a main component, as (meth) an unsaturated monocarboxylic acid of 2).
Only examples of α, β unsaturated monocarboxylic acids, such as acrylic acid, are mentioned. Therefore, the obtained photopolymerizable compound has lower sensitivity as compared with a normal photopolymerizable monomer, and thus it takes a long exposure time and the workability is deteriorated. Alternatively, there is a problem that a photomask is damaged due to a rise in temperature during exposure.

In addition, these photosensitive resin compositions cause a decrease in insulation resistance due to moisture absorption (hereinafter, the magnitude of the decrease is referred to as a measure of moisture resistance) in an attempt to improve the developability in an alkaline aqueous solution or water.

In order to solve these problems, Japanese Patent Laid-Open No.
JP-A-253729 discloses 1) a novolak-type epoxy compound and 2) a (meth) acrylate semi-esterified compound having a hydroxy group of a dibasic acid alone or in a mixture with (meth) acrylic acid; and 3) a polybasic acid anhydride. A photosensitive resin composition using a photopolymerizable compound obtained by sequentially reacting has been proposed. However, these photopolymerizable compounds may have a higher molecular weight during synthesis and / or over time, and thus the photosensitive resin composition using these photopolymerizable compounds may be inferior in developability. . Further, Japanese Patent Laid-Open No.
JP-A-141904 also describes a similar photopolymerizable compound, but does not particularly describe the effects of using these photopolymerizable compounds.

(Problems to be Solved by the Invention) An object of the present invention is to solve the above-mentioned conventional technical problems and to perform ultraviolet exposure using a photopolymerizable compound capable of suppressing the increase in molecular weight during synthesis and / or aging. Photosensitivity with high sensitivity, excellent developability with alkaline aqueous solution, little change in developability over time, and excellent electrical properties, mechanical properties, chemical resistance and moisture resistance of the cured coating The purpose of the present invention is to provide a resin composition.

(Means for Solving the Problems) The present inventors have found that the above problems can be solved by using the following photosensitive resin composition, and have accomplished the present invention.

That is, the object of the present invention is obtained by sequentially reacting at least A) a polyadduct of a novolak type epoxy compound with a (meth) acrylic acid by a Michael addition reaction, and (meth) acrylic acid, and a polybasic acid anhydride. A photopolymerizable compound and a photosensitive resin composition comprising B) a photopolymerization initiator.

 Hereinafter, each component of the present invention will be described.

The photopolymerizable compound (A) is obtained by sequentially reacting a novolak-type epoxy compound, a polyaddition product obtained by a Michael addition reaction of (meth) acrylic acid, (meth) acrylic acid, and a polybasic acid anhydride.

Typical examples of the novolac type epoxy compound include a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, and a halogenated phenol novolac type epoxy resin. These are obtained by reacting phenol, cresol, halogenated phenols and the like with an aldehyde in the presence of an acid catalyst in the presence of an alkali, and reacting epichlorohydrin with a phenolic hydroxyl group of a novolak resin obtained in the presence of an alkali.

The polyadduct obtained by the Michael addition reaction of (meth) acrylic acid is represented by the following general formula.

CH2 = CRCOO (CH2CHRCOO) nH In the formula, R represents hydrogen or a methyl group, and n represents an integer of 1 or more, preferably 12 or less, more preferably 10 or less. If it exceeds 12, the tackiness will increase and it will not be suitable for practical use.

These compounds are usually obtained as a mixture of different n. Commercially available products of such compounds include, for example, Aronix M5600 manufactured by Toa Gosei Chemical Industry Co., Ltd. These compounds are used in combination with (meth) acrylic acid. The reaction sequence at this time is such that even if the polyaddition product of the Michael addition reaction of (meth) acrylic acid and the (meth) acrylic acid are the same, the polyaddition product of the Michael addition reaction of (meth) acrylic acid is first, or It may be later.

Further, as the polybasic acid anhydride, succinic anhydride,
Methyl succinic anhydride, 2,3-dimethyl succinic anhydride, 2,2-dimethyl succinic anhydride, ethyl succinic anhydride, dodecenyl succinic anhydride, nonenyl succinic anhydride, maleic anhydride, methyl maleic anhydride, 2,3-dimethyl maleic anhydride Acid, 2-chloromaleic anhydride, 2,3-dichloromaleic anhydride, bromomaleic anhydride, itaconic anhydride, citraconic anhydride, cis-accotic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, Tetrabromophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, 5- (2,5-di Oxotetrahydrofuryl) -3-me Le-3-cyclohexene-1,2-dicarboxylic acid anhydride, and dibasic acid anhydrides such as glutaric anhydride, trimellitic anhydride, 3,3 ', 4,
Polybasic acid anhydrides such as 4'-benzophenonetetracarboxylic acid can be used. Of these, the dibasic acid anhydrides mentioned above are preferable, and succinic anhydride and tetrahydrophthalic anhydride are particularly preferable.

Each is sequentially reacted to obtain a photopolymerizable compound,
The ratio in which they are reacted is preferably 0.5 to 1.2 equivalents in terms of the total amount of the polyadduct by the Michael addition reaction of (meth) acrylic acid and 1 equivalent of the epoxy group of the novolac epoxy compound, and (meth) acrylic acid. Is 0.8-1.1
And 0.1 to 1.1 equivalents, preferably 0.3 to 1.0 equivalents, of the polybasic anhydride. If the total amount of the polyaddition product by the Michael addition reaction of (meth) acrylic acid and the (meth) acrylic acid is less than 0.5 equivalent, the sensitivity is lowered and the resin gels, and if it exceeds 1.2 equivalents, the problem of tackiness occurs. If the amount of the polybasic acid anhydride is less than 0.1 equivalent, the developing property is reduced. If the amount exceeds 1.1 equivalent, problems such as tackiness and precipitation of crystals occur. Alternatively, the molar ratio of the polyadduct to the (meth) acrylic acid by the Michael addition reaction of (meth) acrylic acid is
95: 9 to 10:90, preferably 95: 5 to 20:80, more preferably
It is from 95: 5 to 40:60. The molar ratio of (meth) acrylic acid is 5
If it is less than 90, the moisture resistance will decrease. If it exceeds 90, the sensitivity and developability will decrease.

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

Examples of the photopolymerization initiator include α-diketones such as benzyl and diacetyl, acyloins such as benzoin, enzoin methyl ether, benzoin methyl ether,
Acyloin ethers such as benzoin isopropyl ether, thioxanthone such as thioxanthone, 2,4-diethylthioxanthone, thioxanthone-1-sulfonic acid, thioxanthone-4-sulfonic acid, benzophenone, 4,4′-bis (diethylamino) benzophenone;
Benzophenones such as 4,4'-bis (diethylamino) benzophenone, acetophenone, p-dimethylaminoacetonephenone, α, α'-dimethoxyacetoxyacetophenone, 2,2'-dimethoxy-2-phenylacetophenone, p-methoxyacetophenone; Acetophenones such as 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone and quinones such as anthraquinone and 1,4-naphthoquinone, phenacyl chloride, tribromomethylphenylsulfone, tris (trichloro Halogen compounds such as methyl) -s-triazine, and peroxides such as di-t-butyl peroxide.

These photopolymerization initiators may be used alone or in combination of two or more. As an example of mixing two or more kinds in this way,
Combination of 2,4,5-triarylimidazole dimer with 2-mercaptobenzoxazole or leuco crystal violet, U.S. Pat.
Combination of 4,4'-bis (dimethylamino) benzophenone with benzophenone or benzoin methyl ether, benzoyl-N-methylnaphthothiazoline and 2,4-bis (trichloromethyl) -6- (US Pat. No. 4,239,850). Combinations with 4-methoxyphenyl) triazine, and combinations of dimethylthioxanthone and 4-dialkylaminobenzoic esters described in JP-A-57-23602.

The total amount of these photopolymerization initiators is preferably 0.08 to 30 parts by weight, and particularly preferably 0.15 to 15 parts by weight, based on the photopolymerizable compound. If it is less than 0.08 part by weight, the sensitivity is lowered, and if it exceeds 30 parts by weight, crystals are precipitated and the lower part is insufficiently cured.

The liquid photosensitive resin composition of the present invention contains at least one polymerizable compound having an ethylenically unsaturated double bond and at least one epoxy group in addition to the above-mentioned photopolymerizable compound and photopolymerization initiator. It is preferable to blend a compound having the same, a thermosetting catalyst for thermally reacting an epoxy group, an organic solvent, a thermal polymerization inhibitor, and the like.

Examples of the polymerizable compound having at least one ethylenically unsaturated double bond include esters of (meth) acrylic acid of a monohydric or polyhydric alcohol.

Examples of the monohydric alcohol in the ester of (meth) acrylic acid of a monohydric or polyhydric alcohol include 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 ether,
Polyethylene glycol monoethyl ether, 2-hydroxy-3-chloropropane, dimethylaminoethyl alcohol, diethylaminoethyl alcohol, glycidol, 2-trimethoxysilylethanol, ethylene chlorohydrin, ethylene bromohydrin, 2,3-dibromopropanol, Allyl alcohol, oleyl alcohol, epoxystearyl alcohol, phenol, naphthol and the like can be mentioned. As polyhydric alcohol,
For example, ethylene glycol, 1,2-propanediol,
1,3-propanediol, 1,4-butanediol, 1,5-
Pentanediol, hexanediol, heptanediol, octanediol, nonanediol, dodecanediol, neopentylglycol, 1,10-decanediol, 2-butene-1,4-diol, 2-n-butyl-2
-Ethylpropanediol, 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,
Pyrogallol, α- (1-aminoethyl) -p-hydroxybenzyl alcohol, 2-amino-2-methyl-1,
3-propanediol, 2-amino-2-ethyl-1,3-
Propanediol, 3-amino-1,2-propanediol, N- (3-aminopropyl) -diethanolamine, N, N-bis (2-hydroxyethyl) piperazine,
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, pentaerythritol, dipentaerythritol, tripetaerythritol, 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. (Meth) of polyhydric alcohol
Among acrylic acid esters, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth)
Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) ) Acrylate, neopentyl glycol di (meth) acrylate, sorbitol hexa (meth) acrylate, sorbitol penta (meth) acrylate and the like are preferred.

Further, (meth) acrylamide of monoamine or polyamine can also be used. Examples of the monoamine here include monoamines such as ethylamine, butylamine, aminoamine, hexylamine, octylamine, cyclohexylamine and 9-aminodecalin, monoalkenylamines such as allylamine, methallylamine and benzylamine, and aniline and toluidine. And aromatic amines such as p-aminostyrene. As the polyamine, for example, ethylenediamine, trimethylenediamine, tetramethylenediamine,
Hexamethylenediamine, octamethylenediamine, hexamethylenebis (2-aminopropyl) amine, diethyltriamine, 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, diaminonaphthalene, diaminostyrene, methylenedianiline, 2, 4-bis (4-aminobenzyl) aniline, aminophenyl ether and the like.

Further, allyl compounds such as formic acid, acetic acid, propionic acid, butyric acid, lauric acid, benzoic acid, chlorobenzoic acid,
Mono- or polyallyl esters of mono- or polycarboxylic acids such as malonic acid, oxalic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid, terephthalic acid, hexahydrophthalic acid, chlorendic acid and trimellitic acid, benzenedisulfonic acid, Mono- or polyallyl esters of mono- or polysulfonic acids such as naphthalenedisulfonic acid,
Diallylamine, N, N'-diallyl oxalic acid diamide,
1,3-diallyl urea, diallyl ether, triallyl isocyanurate and the like can also be used.

Also, for example, divinylbenzene, p-allylstyrene, p-isopropenylstyrene, divinylsulfone,
Polyvinyl compounds such as ethylene glycol divinyl ether, glycerol trivinyl ether, divinyl succinate, divinyl phthalate and divinyl terephthalate, and ionic groups such as 2-hydroxy-3-methacryloyloxypropyltrimethylammonium chloride and methacryloyloxyphenyltrimethylammonium chloride Ester compounds of (meth) acrylic acid can also be used.

Further, commercially available polymerizable monomers or oligomers, for example, Alonix M5700, M6100, manufactured by Toagosei Chemical Industry Co., Ltd.
Acrylic monomers such as M8030, M152, M205, M215, M315, M325, NK ester ABPE- manufactured by Shin-Nakamura Chemical Co., Ltd.
4, U-4HA, CB-1, CBX-1, Nippon Kayaku KAYARAD
R604, DPCA-30, DPCA-60, KAYAMAR PM-1, PM-
2. (meta) such as Sannopco photomers 4061 and 5007
Acrylate monomer, Lipoxy VR6 manufactured by Showa Polymer Co., Ltd.
Epoxy acrylates such as 0, VR90, SP1509 and the like, and Spirane resins having a spiroacetal structure and a (meth) acryl group such as Spirac E-4000X and U3000 manufactured by the same company can also be used.

These compounds can be used alone or as a mixture of two or more kinds.
0% by weight, preferably in the range of 10 to 70% by weight.

Examples of the compound having at least one epoxy group include glycidyl ethers of alcohols having 2 to 20 carbon atoms such as butyl glycidyl ether, octyl glycidyl ether, decyl glycidyl ether, aryl glycidyl ether, phenyl glycidyl ether, and polyethylene glycol diglycidyl. Ether, polypropylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, glycerol triglycidyl ether, Trimethylolpropane triglycidyl ether, diglycerol tetraglycidyl ether Ter, polyglycidyl ethers of polyols such as polyglycerol polyglycidyl ether, 2,6-diglycidylphenyl glycidyl ether, 2,2,2 ′, 6′-tetramethyl-4,4′-biphenyldiglycidyl ether, Bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol F epoxy resin, bisphenol S epoxy resin, hydrogenated bisphenol S epoxy resin, phenol novolak epoxy resin Glycidyl ether type epoxy compounds such as epoxy resin, gresol novolak type epoxy resin, halogenated phenol novolak type epoxy resin and brominated epoxy resin, alicyclic diepoxy acetal, alicyclic diephoxyazi Cycloaliphatic epoxy compounds such as chromatography bets and vinylcyclohexene dioxide, glycidyl (meth) acrylate,
Tetrahydroxyphthalic acid diglycidyl ester, sorbic acid glycidyl ester, unsaturated glycidyl esters such as oleic acid glycidyl ester and linoleic acid glycidyl ester, butyl glycidyl ester,
Alkyl carboxylic acid glycidyl esters such as octyl glycidyl ester, hexahydrophthalic acid diglycidyl ester and dimer acid glycidyl ester, and aromatic carboxylic acids such as benzoic acid glycidyl ester, o-phthalic acid diglycidyl ester and dicricidyl p-oxybenzoic acid Glycidyl ester type epoxy compounds such as glycidyl esters, tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, diglycidylaniline, diglycidyltoluidine, tetraglycidyl-m-xylylenediamine, Glycidyl amine type epoxy compounds such as glycidyl tribromaniline and tetraglycidyl bisaminomethylcyclohexane Ntorein, heterocyclic epoxy compounds such as glycidyl glycidoxy alkyl hydantoin and triglycidyl Jill isocyanurate. Of these, 2,6,2 ', 6'-tetramethyl-4,4'
-Biphenyl diglycidyl ether, novolak type epoxy resin and heterocyclic epoxy compound are preferred.

These epoxy compounds can be used alone or as a mixture of two or more kinds.
To 100% by weight, preferably 20 to 80% by weight.

Examples of thermosetting catalysts for thermally reacting epoxy groups include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine (dipropyltriamine), bis (hexamethylene) triamine, and 1,3,6-trisaminomethyl. Polyamines such as hexane, polymethylene diamines such as trimethylhexamethylenediamine, polyetherdiamine, diethylaminopropylamine, mensendiamine, isophoronediamine, bis (4-amino-3-methylcyclohexyl) methane and N-aminoethyl Aliphatic primary amines such as alicyclic polyamines such as piperazine, metaphenylene diamine, diaminophenylmethane, aromatic primary amines of eutectic mixture of aromatic diamines and polyamines, polyamines Modified amines such as oxy resin adduct, polyamine-ethylene oxide adduct, polyamine-propylene oxide adduct, cyanoethylated polyamine, ketoimine, secondary amines such as piperidine, piperazine, morpholine, and tetramethylguanidine, triethanolamine, benzyldimethylamine Amine compounds such as tertiary amines such as 2,4,6-tris (dimethylaminomethyl) phenol, phthalic anhydride,
Trimellitic anhydride, ethylene glycol bis (anhydrotrimellitate), glycerin tris (anhydrotrimellitate), pyromellitic anhydride, 3,3 ', 4,4'
-Aromatic anhydrides such as benzophenonetetracarboxylic anhydride, maleic anhydride, succinic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, alkenyl Fats such as cyclic aliphatic acid anhydrides such as succinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylcyclohexenetetracarboxylic anhydride, polyadipic anhydride, polyazeline anhydride, polysebacic anhydride Group anhydride, and chlorendic anhydride, acid anhydrides such as halogenated anhydrides such as tetrabromophthalic anhydride, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-
Heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1
-Cyanoethyl-2-phenylimidazolium trimellitate, 2-methylimidazolium isocyanurate, 2-phenylimidazolium isocyanurate,
2,4-diamino-6- [2-methylimidazolyl-
(1)]-Ethyl-S-triazine, 2,4-diamino-
6- [2-ethyl-4-methylimidazolyl- (1)]
-Ethyl-S-triazine, 2,4-diamino-6- [2
-Undecylimidazolyl- (1)]-ethyl-S-triazine, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-cyanoethyl-2-phenyl- 4,5-di (cyanoethoxymethyl) imidazole,
Imidazole compounds such as 1-dodecyl-2-methyl-3-benzylimidazolium chloride and 1,3-dibenzyl-2-methylimidazolium chloride;
Phenols such as novolak type phenolic resin, cresol type phenolic resin, resorcinol type phenolic resin and polyvinyl phenol, Lewis acids such as boron trifluoride-amine complex, boron pentafluoride-amine complex and arsenic pentafluoride-amine complex Amine complexes, dicyandiamide, o-tolylbiguanide, dicyandiamide derivatives such as phenylbiguanide and α-2,5-dimethylbiguanide, organic acid hydrazides such as succinic hydrazide, adipic hydrazide, isophthalic hydrazide and p-oxybenzoic hydrazide. , Diaminomaleonitrile, benzyldiaminomaleonitrile and other diaminomaleonitrile derivatives, melamine and N, N-diallylmelamine and other melamine derivatives, amine imide derivatives, polymercaptans It can be used in the known epoxy curing accelerator.

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

Examples of the organic solvent include methyl ethyl ketone, ketones such as cyclohexane, aromatic hydrocarbons such as toluene and xylene, cellosolves such as cellosolve and butyl cellosolve, carbitols such as carbitol and butyl carbitol, ethyl acetate, and butyl acetate. Cellosolve acetate,
There are acetic acid esters such as butyl cellosolve acetate, carbitol acetate, and butyl carbitol acetate.

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

Examples of the thermal polymerization inhibitor include hydroquinone, p
-Methoxyphenol, pt-butylcatechol, 2,
Aromatic hydroxy compounds such as 6-di-t-butyl-p-cresol, β-naphthol, and pyrogallol; quinones such as benzoquinone and p-toluquinone; amines such as naphthylamine, pyridine, p-triidine and phenothiazine; Aluminum salts or ammonium salts of nitrosophenylhydroxylamine, chloranil, nitrobenzene and the like can be mentioned.

Further, the photosensitive resin composition of the present invention includes a tackifier, an adhesion promoter, a dispersant, a plasticizer, an anti-sagging agent, a leveling agent, an antifoaming agent, a flame retardant, a brightener, a coloring agent, and the like. Supplementary additives may be incorporated as needed.

Examples of the tackifier or the adhesion promoter include alkylphenol / formaldehyde novolak resin, polyvinyl ethyl ether, polyvinyl isobutyl ether, polyvinyl butyral, polyisobutylene, styrene-butadiene copolymer rubber, butyl rubber, vinyl chloride-vinyl acetate copolymer, Examples thereof include chlorinated rubber, acrylic resin-based pressure-sensitive adhesives, aromatic, aliphatic, and alicyclic petroleum resins.

The addition of the tackifier or the adhesion promoter enhances the adhesion of the photosensitive resin after photo-curing to the substrate, and particularly when used for a copper printed wiring board and a solder printed wiring board, the effect is greatly exhibited. .

The dispersant is used for improving the dispersibility, storage stability and the like of the liquid photosensitive composition. The necessity of blending a plasticizer, an anti-sagging agent, a leveling agent, and an antifoaming agent depends on the method of using the photosensitive resin composition, that is, the method of forming a coating film of the photosensitive resin composition, and the type and amount used. Is appropriately selected.

These supplementary additives may not only exhibit one kind of property (dispersibility, plasticity, anti-sagging, leveling or defoaming properties), but may also exhibit a plurality of additive effects. For example, the dispersant may also act as a superplasticizer, leveling agent and defoaming agent for the photosensitive resin composition, and the dispersing agent, anti-sagging agent, leveling agent and defoaming agent may be used as a photosensitive resin after photocuring. It also has an effect on the glossiness of the hydrophilic resin composition and sometimes acts as a brightener.

As the dispersant, for example, a fluorine-containing polymer compound, a surfactant, a modified lecithin, a non-silicon-based amine salt of a long-chain carboxylic acid, an organic montmorillite, or the like is used.

As the plasticizer, for example, ethylene glycol diphthalate, diethylene glycol diphthalate, ethylene glycol dicaprate, glycol esters such as diethylene glycol dicaprate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diaryl phthalate,
Phthalates such as butylbenzyl phthalate, phosphates such as triphenyl phosphate and tricresyl phosphate, diethyl malate, dibutyl adipate, triethyl citrate, ethyl laurate and the like are used.

As the anti-sagging agent, for example, inorganic fine powder such as talc, mica, silicon dioxide, titanium dioxide, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, magnesium sulfate, barium sulfate and the like are used.

Examples of the coloring agent include inorganic pigments such as titanium oxide, carbon black, and iron oxide; organic dyes such as methylene blue, crystal violet, rhodamine B, fuchsin, auramine, azo dyes, and anthraquinone dyes;
A phthalocyanine-based or azo-based organic pigment such as phthalocyanine blue and phthalocyanine green is used.

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 flame retardants such as decane, tetrabromobenzene, and chlorinated diphenyl; and phosphorus such as vinylphosphonate, allylphosphonate, tris (β-chloroethyl) phosphonate, tricresylphosphonate, and ammonium phosphate A flame retardant is used.

When an image is formed using the photosensitive resin composition of the present invention thus obtained, the photosensitive resin composition is applied to a substrate, and then heated and cured to make the surface non-adhesive, and then cured. The film is brought into close contact with a pattern mask, exposed and developed with an alkaline aqueous solution, and the uncured film is eluted to obtain an image.

Examples of the method of applying the photosensitive resin composition of the present invention on a substrate include, for example, spraying, dipping, brushing, roller coating, flow coater, curtain coating, screen printing, and the like. In particular, for coating on a printed wiring board or a thin film metal, a roller coating method, a curtain coating method, a screen printing method, or the like is preferable.

In the photosensitive resin composition of the present invention, it is preferred that the coating film is cured by heating before irradiation with actinic light to eliminate the tackiness of the coating film surface. As a result of heating and curing in this manner, the cured coating film becomes non-adhesive, and it becomes possible to expose the cured coating film with the pattern mask adhered thereto.

Exposure light sources used for photocuring the photosensitive resin composition of the present invention include a low-pressure mercury lamp, a hydraulic mercury lamp, a high-pressure mercury lamp,
Examples include an ultra-high pressure mercury lamp, a xenon lamp, a metal halide lamp, and a laser beam. It is preferable to use an exposure apparatus using a high-pressure mercury lamp, an ultra-high pressure mercury lamp, or a metal halide lamp that emits ultraviolet light having a wavelength of about 300 to 400 nm as a light source.

The photosensitive resin composition of the present invention can be developed with an alkaline aqueous solution. As the developer, for example, an aqueous solution of 0.1 to 10% by weight of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, ammonia or the like can be used, but in some cases, amine Classes, such as butylamine,
1 such as hexylamine, benzylamine, allylamine
Secondary amine such as tertiary amine, diethylamine, benzylethylamine, tertiary amine such as triethylamine, hydroxylamine such as ethanolamine, diethanolamine, triethanolamine, 2-amino-1,3-propanediol, morpholine, pyridine, piperazine, Cyclic amines such as piperidine, polyamines such as hydrazine, ethylenediamine, hexamethylenediamine, basic salts such as sulfates, carbonates, bicarbonates, alkali metal phosphates and pyrophosphates of the amines, teramethylammonium hydroxide And quaternary ammonium salt hydroxides such as choline.

Further, after the image formation, the photosensitive resin composition of the present invention may be subjected to post-curing by heat treatment, if necessary.

A heating device such as a hot air circulation drying oven or a far-infrared drying oven can be used for the heat treatment in curing before exposure and post-curing after image formation.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. Unless otherwise specified, parts are parts by weight
Represents

(Synthesis Example) 50 parts of a cresol novolak type epoxy resin having an epoxy equivalent of 210 (Epiclon N-673 manufactured by Dainippon Ink and Chemicals, Inc.), 0.54 part of benzyltriethylammonium chloride, 0.07 part of hydroquinone, and the unsaturated carboxylic acid of the parts by weight shown in Table 1 The acid (1.05 equivalents to the epoxy group) is dissolved in the carbitol acetate of the weight shown in Table 1 at 80 ° C.
Stir for 12 hours.

To this reaction product was added 35.5 parts of tetrahydrophthalic anhydride (0.98 equivalents based on the epoxy group), and further added at 80 ° C.
For 2.5 hours, the photopolymerizable compounds 1 to 6
Was obtained.

Table 3 shows the weight average molecular weight (in terms of polystyrene) of the photopolymerizable compound immediately after its synthesis and after being aged for 4 weeks at room temperature.
It is shown in FIG.

(Examples and Comparative Examples) Examples 1 to 3 and Comparative Examples 1 to 3 Photopolymerizable compounds 1 to 6 shown in Synthesis Examples were used one week after the synthesis, and photosensitive liquids M1 to M6 were prepared according to the following formulations. , A thermosetting liquid N was prepared.

The photosensitive liquid M and the thermosetting liquid N were separately kneaded by a roll mill to prepare inks.

Next, the photosensitive liquid M and the thermosetting liquid N were kneaded to obtain a liquid photosensitive resin composition.

Table 2 shows the results of evaluating the performance of these liquid photosensitive resin compositions by the following methods.

1. Formation of coating film The copper-clad laminate was pretreated by polishing, washing, and removing moisture. A photosensitive resin composition prepared under various conditions was applied onto the entire surface of the pretreated copper-clad laminate by a screen printing method, and dried at 70 ° C. for 30 minutes in a hot air circulation drying oven to obtain a coating film.

2. Evaluation of developability The coating film was developed under the following conditions, and the time required for dissolving the coating film was measured.

Developer: 1% aqueous sodium carbonate solution Temperature: 25 ° C. Spray pressure: 1.8 kg / cm ^{2 In} practical use, the development time is preferably within 10 seconds.

3. Evaluation of Sensitivity A step wedge with a density step of 0.15 (ΔlogE) is brought into close contact with the coating film, exposed to 1000 mj / cm ² with a 5KW ultra-high pressure mercury lamp, and developed for twice the time required for dissolving the coating film. Was obtained, and the number of stages at which the image was completely eluted (the number of clear stages) was examined.

 The higher the number, the higher the sensitivity.

4. Evaluation of pencil hardness Solid exposure at an exposure amount at which the number of clear steps becomes 12, and after development in the same manner as in 3, after-curing in a hot-air drying oven at 140 ° C. for 50 minutes, to IJS K 5400 6-14 It measured according to.

5. Evaluation of Adhesion In the same manner as in the evaluation of the pencil hardness, exposure, development, and post-curing were performed, and a base test was performed according to JIS K 5400 6-15.

6. Evaluation of insulation resistance Except for using a double-sided copper-clad laminate on which an IPC-B-25 test pattern was formed, exposure, development, and post-curing were performed in the same manner as in the pencil hardness evaluation method, and according to JIS Z 3197. Then, DC500V was applied using "TR-8601" manufactured by Advantest Co., Ltd., and the resistance value after one minute was examined.

7. Evaluation of insulation resistance after moisture absorption In the same manner as the evaluation of insulation resistance, exposure, development, and post-curing are performed, and after aging for 4 days in an atmosphere of 40 ° C. and 90% relative humidity, the same as the evaluation of insulation resistance is performed. To determine the resistance.

In 6 and 7, the resistance value is preferably 1 × 10 ¹¹ or more.

8. Evaluation of solvent resistance In the same manner as in the evaluation of insulation resistance, exposure, development, and post-curing are performed, and the sample is immersed in 1,1,1-trichloroethane at 20 ° C. for 1 hour, and the state of the coating film is determined. The adhesion was comprehensively judged.

9. Evaluation of acid resistance As in the case of solvent resistance, exposure, development, and post-curing were performed, and the sample was immersed in a 10 vol% sulfuric acid aqueous solution at 20 ° C for 30 minutes. It was judged comprehensively.

Example 5 A photosensitive liquid M and a thermosetting liquid N were prepared in the same manner as in Example 1 except that the photopolymerizable compound 2 shown in Synthesis Example was used 5 weeks after the synthesis, and the performance was evaluated. The performances before aging were not much different, and the developing time was 9 seconds, which was not much different from before.

Comparative Example 4 A photosensitive liquid M and a thermosetting liquid N were prepared in the same manner as in Example 1 except that the photopolymerizable compound 6 shown in Synthesis Example was used 5 weeks after the synthesis, and the performance was evaluated. There were no great differences in other performances from before the aging, but the developability was reduced to 15 seconds, which was not practically preferable.

(Effects of the Invention) As is clear from the above examples, the photosensitive resin composition of the present invention has high sensitivity to ultraviolet exposure, excellent developability with an alkaline aqueous solution, and further, during synthesis and / or aging. Since it uses a photopolymerizable compound with a low molecular weight, there is little change in developability over time, and it is a composition with excellent electrical properties, mechanical properties, chemical resistance, and moisture resistance of the cured film. And a photosensitive resin composition useful as a permanent protection mask for printed wiring boards.

Claims (1)

(57) [Claims] 1. At least A) a polyaddition product by a Michael addition reaction of a novolac type epoxy compound and (meth) acrylic acid, and (meth)
A photosensitive resin composition comprising: a photopolymerizable compound obtained by sequentially reacting acrylic acid and polybasic acid anhydride; and B) a photopolymerization initiator, and not containing calcined kaolin.