JP7392061B2 - Photosensitive resin composition, plating method, and metal pattern manufacturing method - Google Patents

Description

The present invention relates to a photosensitive resin composition, a plating method using the photosensitive resin composition, and a method for manufacturing a metal pattern.

In recent years, as electronic devices have become smaller and lighter, patterns on printed wiring boards, metal masks, etc. have become increasingly finer. Therefore, in the production of conductor circuits for printed wiring boards or the production of metal masks, metal layers are produced by an additive method using a photosensitive resin composition and electrolytic plating.

For example, in the (semi-)additive method for printed wiring boards, first a thin electroless plating layer is formed on the surface of an insulating resin such as glass epoxy resin by electroless plating, and then a photosensitive resin composition containing a photosensitive resin composition is applied to the surface of the copper layer. A photosensitive resin layer is formed, then exposed and developed to form a resist pattern, and then a thick electrolytic plated layer is laminated by electrolytic plating, the resist pattern is peeled off, and the electroless plating that appears after peeling. This is a method of etching a layer (for example, Patent Document 1).

For example, as a method for producing a metal mask, a first step of forming a photosensitive resin layer containing a photosensitive resin composition with a predetermined thickness on a substrate, and an opening of the metal mask on the photosensitive resin layer. a second step of pattern exposure according to the pattern; a third step of developing and removing only the unexposed portions of the photosensitive resin layer to form a resist pattern and exposing the substrate; After performing a fourth step of forming a metal mask material layer on the exposed portion by electrolytic plating, a fifth step of removing the remaining photosensitive resin layer and a sixth step of separating the metal mask material layer from the substrate are performed. There is a manufacturing method (for example, Patent Document 2).

In these methods, a resist pattern with a narrow pitch is formed, electrolytic plating is performed between the narrow spaces, and a thick metal layer is formed to become an electroplated layer or a metal mask material layer. However, in the subsequent resist peeling process, which is a process of peeling off the resist pattern or removing the remaining photosensitive resin layer, the resist pattern is not peeled off properly, and resist peeled pieces appear on the printed wiring board or metal mask. There was a problem in that some remained.

In order to solve this problem of resist peeling, photosensitive resin compositions that have high adhesion to substrates and are soluble in resist stripping solutions have been proposed (see, for example, Patent Documents 3 to 6). If the solubility in the resist stripping solution is good, the problem of resist stripping pieces remaining between narrow spaces can be eliminated.

Patent Documents 3 to 6 disclose photosensitive resin compositions in which the content of methacrylate monomers is reduced and the content of acrylate monomers is increased as crosslinking monomers in order to increase the solubility of the photosensitive resin compositions in resist stripping solutions. things are being proposed. However, when the content of acrylate monomer is increased, the photosensitive resin layer swells during alkaline development due to the high hydrophilicity of the photosensitive resin composition, and as a result, when the resist thickness is as thick as 50 μm or more, There are problems such as difficulty in resolving narrow resist spaces, and problems in which fine lines and dots tend to peel off from the substrate during resist pattern formation and plating processes.

Therefore, it has the property of being soluble in resist stripping solutions, and even in resist patterns with fine lines and dots, it is stably retained on the substrate during pattern formation and plating processes, and has a photosensitive property that has high resolution. Resin compositions are desired.

Japanese Patent Application Publication No. 2004-101617 Japanese Patent Application Publication No. 4-166844 Japanese Patent Application Publication No. 9-265180 Japanese Patent Application Publication No. 2010-113349 JP2011-081031A Japanese Patent Application Publication No. 2013-037272

The object of the present invention is to enable easy resist peeling even in a narrow pitch resist pattern, maintain fine lines and dots stably on a substrate during pattern formation and plating processes, and have high resolution. It is an object of the present invention to provide a photosensitive resin composition, a plating method using the photosensitive resin composition, and a method for manufacturing a metal pattern.

As a result of intensive study to solve the above problem, the following means were discovered.

<1>
Contains (A) an alkali-soluble resin, (B) a photopolymerization initiator, and (C) an acrylate monomer,
The content of (D) methacrylate monomer is 0 to 5% by mass with respect to (C) acrylate monomer,
(C) Contains (C1) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by the general formula (i), where l + m + n + o = 24 to 48) as an acrylate monomer,
(C) The content of (C1) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by general formula (i), where l + m + n + o = 24 to 48) is 30 to 70% by mass based on the total amount of acrylate monomer. A photosensitive resin composition characterized by:

<2>
The photosensitive resin composition contains (C2) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by the general formula (i), where l + m + n + o = 4 to 8) as the (C) acrylate monomer, and (C) ) The content of (C2) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by the general formula (i), where l + m + n + o = 4 to 8) is 30 to 70% by mass based on the total amount of acrylate monomers <1 ＞The photosensitive resin composition described above.

<3>
The photosensitive resin composition contains (E) a polymerization inhibitor, with respect to the total amount of (A) alkali-soluble resin, (B) photopolymerization initiator, (C) acrylate monomer, and (E) polymerization inhibitor, (E) The photosensitive resin composition according to <1>, wherein the content of the polymerization inhibitor is 400 to 1000 ppm.

<4>
The photosensitive resin composition contains (F) a photocolor former, and the total amount of (A) alkali-soluble resin, (B) photopolymerization initiator, (C) acrylate monomer, and (F) photocolor former is ( F) The photosensitive resin composition according to <1>, wherein the content of the photochromic agent is 0.15 to 1.5% by mass.

<5>
A photosensitive resin layer containing the photosensitive resin composition according to any one of <1> to <4> is formed on a base material, then pattern exposure is performed to harden the exposed area, and then alkaline development is performed. A plating method comprising: removing a photosensitive resin layer in non-exposed areas to form a resist pattern including a cured photosensitive resin layer, and then plating the exposed base material.

<6>
A method for manufacturing a metal pattern, comprising forming a metal pattern on a base material using the plating method described in <5>.

According to the present invention, resist peeling is easy even in a narrow pitch resist pattern, fine lines and dots are stably held on a substrate during pattern formation and plating processes, and high resolution is achieved. It is possible to provide a photosensitive resin composition having the present invention and a plating method using the photosensitive resin composition.
Further, according to the present invention, it is easy to peel off the resist after pattern formation, and the resist pattern is stably held on the base material, so fine lines and dots are not formed on the base material during the plating process. , metal patterns with high resolution can be formed.

Hereinafter, the photosensitive resin composition and plating method of the present invention will be explained in detail.

The photosensitive resin composition of the present invention contains (A) an alkali-soluble resin, (B) a photopolymerization initiator, and (C) an acrylate monomer, and contains (D) a methacrylate monomer relative to the (C) acrylate monomer. contains (C1) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by the general formula (i), where l + m + n + o = 24 to 48) as the (C) acrylate monomer, and ( C) The content of (C1) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by general formula (i), where l + m + n + o = 24 to 48) is 30 to 70% by mass based on the total amount of acrylate monomers. It is characterized by

l, m, n, and o in general formula (i) are all repeating unit numbers in general formula (i), and all are natural numbers.

In the alkali-soluble resin (A) in the present invention, "alkali-soluble" means that when the target resin is formed into a film and immersed in a 1% by mass sodium carbonate aqueous solution at 25°C for 10 minutes, the film thickness is 0.01 μm or more. Refers to the property of dissolving.
Specifically, the alkali-soluble resin (A) is a resin containing an acidic group, and includes a resin having an acid value of 40 mgKOH/g or more. Specific examples of the acidic group include carboxyl group, phenolic hydroxyl group, sulfonic acid group, and phosphoric acid group.

(A) Examples of the alkali-soluble resin include organic polymers such as (meth)acrylic resin, styrene resin, epoxy resin, amide resin, amide epoxy resin, alkyd resin, and phenol resin. . These may be used alone or in combination of two or more.

Among these, it is preferable to use (meth)acrylic resin. As the (meth)acrylic resin, a (meth)acrylic polymer mainly composed of (meth)acrylate and copolymerized with ethylenically unsaturated carboxylic acid is preferable. Moreover, this may be one obtained by copolymerizing other copolymerizable monomers having an ethylenically unsaturated group.

Examples of the (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate Acrylate, lauryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-(dimethylamino)ethyl (meth)acrylate, 2-(diethylamino)ethyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, ) acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, and the like.
In addition, when described as "(meth)acrylic type", "(meth)acrylate", etc., it means "acrylic type or methacrylic type", "acrylate or methacrylate", etc., respectively.

As the ethylenically unsaturated carboxylic acid, monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid are preferably used, and dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, and their anhydrides and half esters are preferably used. It can also be used. Among these, acrylic acid and methacrylic acid are particularly preferred.

Examples of the other copolymerizable monomers having an ethylenically unsaturated group include styrene, α-methylstyrene, p-methylstyrene, p-ethylstyrene, p-methoxystyrene, p-ethoxystyrene, and p-chlorostyrene. Examples include styrene, p-bromostyrene, (meth)acrylonitrile, (meth)acrylamide, diacetone acrylamide, vinyltoluene, vinyl acetate, and vinyl-n-butyl ether.

(A) The acid value of the alkali-soluble resin affects the alkali development rate, resist peeling rate, exposure sensitivity, softness of the photosensitive resin layer, adhesion between the photosensitive resin layer and the substrate, and the like. The acid value of the alkali-soluble resin (A) is preferably 40 to 500 mgKOH/g, more preferably 100 to 300 mgKOH/g.
If the acid value is less than 40 mgKOH/g, the alkaline development time may become long; on the other hand, if it exceeds 500 mgKOH/g, the adhesion between the photosensitive resin layer and the substrate may deteriorate. The above acid value is a value measured in accordance with JIS K2501:2003.

Furthermore, the weight average molecular weight of the alkali-soluble resin (A) is preferably from 5,000 to 150,000, more preferably from 10,000 to 100,000. If the weight average molecular weight of the alkali-soluble resin (A) is less than 5,000, it may be difficult to form the photosensitive resin composition into a film before curing. On the other hand, if the weight average molecular weight of the alkali-soluble resin (A) exceeds 150,000, the solubility in an alkaline developer may deteriorate or the rate of dissolution in a resist stripping solution may become slow.

(B) As the photopolymerization initiator, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2 - Aromatic ketones such as morpholino-propan-1-one; 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenyl Anthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone quinones such as; benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin compounds such as benzoin, methylbenzoin, and ethylbenzoin; benzyl dimethyl ketal, 1-hydroxy-cyclohexyl-phenyl-ketone, 2- Hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy -1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-(dimethylamino)-2-[(4-methyl Alkylphenones such as phenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone; 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6- Acylphosphine oxides such as trimethylbenzoyl)-phenylphosphine oxide; 1,2-octanedione, 1-[4-(phenylthio)-,2-(o-benzoyloxime)], ethanone, 1-[9- Oxime esters such as ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(o-acetyloxime); 2-(o-chlorophenyl)-4,5-diphenylimidazole 2-(o-chlorophenyl)-4,5-bis(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxy 2,4,5-triarylimidazole dimers such as phenyl)-4,5-diphenylimidazole dimer and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer; 9-phenylacridine , 1,7-bis(9,9'-acridinyl)heptane and other acridine derivatives; N-phenylglycine, N-phenylglycine derivatives; Coumarin compounds; benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone , hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 4,4'-bis(dimethylamino) Examples include benzophenone compounds such as benzophenone and 4,4'-bis(diethylamino)benzophenone.

The substituents on the aryl groups of the two 2,4,5-triarylimidazole in the above 2,4,5-triarylimidazole dimer may be the same and give a symmetrical compound, or they may be different. Asymmetric compounds may also be provided. Furthermore, a thioxanthone compound and a tertiary amine compound may be combined, such as a combination of diethylthioxanthone and dimethylaminobenzoic acid.
These may be used alone or in combination of two or more. Among these, imidazole dimer is highly sensitive and can be preferably used, and furthermore, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer can be usefully used.

The photosensitive resin composition of the present invention contains (C1) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by the general formula (i), where l + m + n + o = 24 to 48) as the (C) acrylate monomer. By containing (C1), while maintaining the property that resist pieces dissolve during resist peeling, the cured photosensitive resin layer exhibits less swelling during alkaline development and has excellent adhesion to the substrate. , it is possible to achieve the effect that fine lines and dots are stably maintained during pattern formation and plating processes.

If the value of l+m+n+o in (C1) is smaller than 24, undercuts (thinning of the image line width at the bottom of the resist) may become large, and if the value of l+m+n+o is larger than 48, the photosensitivity may be reduced by alkaline development. The resin layer tends to swell, and a fine pattern may not be formed in some cases. Therefore, the value of l+m+n+o in (C1) is from 24 to 48, more preferably from 30 to 40.

The photosensitive resin composition of the present invention contains (C2) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by the general formula (i), where l+m+n+o=4 to 8) as the (C) acrylate monomer. is preferred. By containing (C2), the photosensitive resin layer has less swelling during alkaline development and has excellent adhesion to the substrate, while maintaining the property that the resist peeling pieces dissolve during resist peeling. More effective.

If the value of l+m+n+o in (C2) is smaller than 4, undercuts may become large, and if the value of l+m+n+o is larger than 8, the photosensitive resin layer will easily swell during alkaline development, resulting in a fine pattern. may not be formed. Therefore, the value of l+m+n+o in (C2) is 4 to 8, more preferably 4.

(C) The acrylate monomer may contain "(C3) an acrylate monomer other than (C1) and (C2)". Examples of (C3) include compounds having one or more acryloyl groups.

Examples of (C3) having one acryloyl group include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl Acrylate, cyclohexyl acrylate, benzyl acrylate, isomyristyl acrylate, stearyl acrylate, nonylphenoxy polyethylene glycol acrylate (one or more ethoxy groups), 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl acrylate, lauryl acrylate, tetrahydrofurfuryl acrylate , 2-(dimethylamino)ethyl acrylate, 2-(diethylamino)ethyl acrylate, 2,2,2-trifluoroethyl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, glycerin monoacrylate, methoxypolyethylene glycol acrylate (2 to 30 ethoxy groups), phenoxypolyethylene glycol acrylate (2 to 30 ethoxy groups), methoxypolypropylene glycol acrylate (2 to 30 propoxy groups), phenoxypolypropylene glycol acrylate (2 to 30 propoxy groups), 2- Examples include acryloyloxyethyl succinate, 2-hydroxy-3-phenoxypropyl acrylate, and ethoxylated o-phenylphenol acrylate.
"Ethoxy group" is "-CH2CH2O-". The "propoxy group" is "-C3H6O-" and may be linear or branched.

Further, examples of (C3) having two acryloyl groups include a compound obtained by reacting a polyhydric alcohol with two acrylic acids. Also, for example, ethylene glycol diacrylate, polyethylene glycol diacrylate (the number of ethoxy groups is 2 to 30), propylene glycol diacrylate, polypropylene glycol diacrylate (the number of propoxy groups is 2 to 30), polytetramethylene glycol diacrylate, neopentyl glycol Diacrylate, 3-methyl-1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, 1,10-decanediol diacrylate, 1,9-nonanediol diacrylate, dimethyloltricyclodecane diacrylate , diacrylate of ethylene oxide adduct of bisphenol A (2 to 30 ethoxy groups), diacrylate of propylene oxide adduct of bisphenol A (2 to 40 propoxy group), ethylene oxide and propylene oxide adduct of bisphenol A Diacrylate (sum of ethoxy and propoxy groups is 2 to 40), hydroxypivalate neopentyl glycol diacrylate, 9,9-bis[4-(2-acryloyloxyester)phenyl]fluorein, tricyclodecane dimethanol Examples include diacrylate.

Further, examples of (C3) having three or more acryloyl groups include compounds obtained by reacting polyhydric alcohol with acrylic acid. Also, for example, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, ethylene oxide modified pentaerythritol triacrylate, trimethylolpropane triacrylate, Glycidyl ether triacrylate, ethylene oxide modified isocyanuric acid triacrylate, ε-caprolactone modified tris-(2-acryloxyethyl) isocyanurate, glycerin triacrylate, ethylene oxide modified glycerin triacrylate, ethylene oxide modified pentaerythritol tetraacrylate (general formula Compounds represented by (i) in which l+m+n+o is less than 4, more than 8 and less than 24, and more than 48).

Examples of the methacrylate monomer (D) include compounds in which the acryloyl group of the acrylate monomer (C) above is replaced with a methacryloyl group.
The photosensitive resin composition of the present invention may contain (D) a methacrylate monomer, and the content thereof is 0 to 5% by mass based on the (C) acrylate monomer. (D) When the content of the methacrylate monomer exceeds 5% by mass, peeled pieces of the cured photosensitive resin layer become large and do not dissolve when the resist is peeled off.

The content of (C1) in the present invention is 30 to 70% by mass, more preferably 35 to 65% by mass, and even more preferably 40 to 60% by mass, based on the total amount of acrylate monomer (C).
If the content is less than 30% by mass, or if the content is too small, undercuts may become large; if the content is more than 70% by mass, or if the content is too large, the alkali The photosensitive resin layer is likely to swell during development, resulting in poor adhesion or peeling of fine lines or dots during development.

Moreover, it is preferable that the photosensitive resin composition of this invention contains (C2). The content of (C2) is preferably 30 to 70% by mass, more preferably 40 to 60% by mass, based on the total amount of acrylate monomer (C). If the content is less than 30% by mass, the photosensitive resin layer may easily swell during alkaline development, resulting in poor adhesion, and if the content is more than 70% by mass, the cured film may become hard. Since the resist becomes brittle, the resist may be chipped by contact with conveyance rollers, etc.

In the photosensitive resin composition of the present invention, the content of (A) is preferably 30 to 75% by mass based on the total amount of (A), (B), (C) and (D), and 35% by mass. It is more preferably 70% by mass, and even more preferably 40% to 60% by mass. If the content of (A) is less than 30% by mass, film properties may deteriorate or alkali developability may deteriorate. If the content of (A) exceeds 70% by mass, the resolution of the resist pattern may decrease.

The content of (B) is preferably 0.1 to 10% by mass, and 0.2 to 5% by mass based on the total amount of (A), (B), (C) and (D). It is more preferable. If the content of (B) is less than 0.1% by mass, photopolymerizability may become insufficient. On the other hand, if it exceeds 10% by mass, absorption may increase on the surface of the photosensitive resin layer during exposure, resulting in insufficient photocrosslinking within the photosensitive resin layer.

The content of (C) is preferably 15 to 60% by mass, more preferably 17 to 55% by mass based on the total amount of (A), (B), (C) and (D). , more preferably 20 to 50% by mass. If the content of (C) is less than 15% by mass, crosslinking properties may decrease and photosensitivity may become insufficient. On the other hand, if it exceeds 55% by mass, the tackiness of the film surface may increase.

It is preferable that the photosensitive resin composition of the present invention contains (E) a polymerization inhibitor, and (E) the polymerization inhibitor is More preferably, the content is 400 to 1000 ppm.

(E) The polymerization inhibitor has the effect of suppressing the photocuring ability of the photosensitive resin composition.
(E) The polymerization inhibitor is not particularly limited as long as it can capture radicals and stop the photochemical reaction of the photosensitive resin composition, but examples include hydroquinone, methylhydroquinone, 4-methoxyphenol, 2, 5-di-tert-butylhydroquinone, tert-butylhydroquinone, 2,6-di-tert-butyl-p-cresol, p-benzoquinone, methyl-p-benzoquinone, tert-butyl-p-benzoquinone, catechol, 4- Examples include hydroquinones such as tert-butylcatechol, 3-methoxycatechol, pyrogallol, and picric acid.
In addition, phenoxazine, 3,7-bis(diethylamino)phenoxazin-5-ium perchlorate, 5-amino-9-(dimethylamino)-10-methylbenzo[a]phenoxazin-7-ium chloride, etc. Examples include sazin derivatives.
Further examples include copper chloride, N-nitrosophenylhydroxylamine aluminum salt, and the like.

(E) The polymerization inhibitor not only improves the storage stability of the photosensitive resin composition but also improves the resolution of the resist pattern. These can be used alone or in combination of two or more. Among them, 4-methoxyphenol is preferably used in terms of storage stability, solubility in solvents, and the like.

The content of (E) is preferably 400 to 1000 ppm, more preferably 500 to 900 ppm, based on the total amount of (A), (B), (C) and (E). If the content of (E) is less than 400 ppm, resolution and adhesion may decrease. On the other hand, if it exceeds 1000 ppm, sensitivity may become insufficient.

The photosensitive resin composition of the present invention preferably contains (F) a photocoloring agent, and the (F) photocoloring agent is It is more preferable that the content is 0.15 to 1.5% by mass.

(F) The photochromic agent is not particularly limited, but includes, for example, leuco crystal violet, leuco victoria blue BH, leuco victoria pure blue BOH, leuco diamond green, leuco acid violet 5B, leuco solar cyanine 6B, leuco brilliant green, 3 , 6-bisdiethylamino-9-phenylxanthene and the like. Among these, leuco crystal violet is preferably used from the viewpoint of color development, discoloration, color tone, etc.

The content of (F) is preferably 0.15 to 1.5% by mass, more preferably 0.2% by mass based on the total amount of (A), (B), (C) and (F). ~1.0% by mass. If the content of the photochromic agent is less than 0.15% by mass, the contrast between exposed areas and unexposed areas may decrease when the photosensitive resin layer is exposed. On the other hand, if the content of (F) exceeds 1.5% by mass, (F) may not be completely dissolved and may precipitate as crystals inside the photosensitive resin layer, or the storage stability of the photosensitive resin composition may increase. performance may decrease.

The photosensitive resin composition of the present invention may contain components other than the above (A) to (F), if necessary. Such ingredients include solvents, plasticizers, colorants (pigments, dyes, pigments), photoreducing agents, thermal color inhibitors, fillers, antifoaming agents, flame retardants, adhesion agents, leveling agents, and release agents. Examples include accelerators, antioxidants, fragrances, thermosetting agents, water repellents, oil repellents, etc. (A), (B), (C), (D), (E) and (F), respectively. It can be contained in an amount of about 0.01 to 20% by mass based on the total amount. These can be used alone or in combination of two or more.

The photosensitive resin composition of the present invention may have a dry film resist structure in which a support, a photosensitive resin layer containing the photosensitive resin composition, and a cover film are laminated. Hereinafter, "dry film resist" may be simply abbreviated as "DFR".
The support only needs to be peelable from the uncured or cured photosensitive resin layer, and is preferably a transparent film that transmits actinic rays. The thinner the support is, the less light is refracted, and the thicker the thickness is, the better the coating stability is. Particularly preferred is 5 to 50 μm. Examples of such films include films of polyethylene terephthalate, polycarbonate, and the like.

The cover film only needs to be peelable from the uncured photosensitive resin layer, and a resin with high mold releasability is used. Examples include polyethylene film; polypropylene film; polyalkylene film coated with a release agent such as silicone; and the like.
The photosensitive resin layer is a layer made of the photosensitive resin composition of the present invention.

In the case of a dry film resist structure, the thickness of the photosensitive resin layer is preferably 10 to 150 μm, more preferably 30 to 120 μm. If the thickness of this photosensitive resin layer is too large, problems such as decreased resolution and increased cost will likely occur. On the other hand, if it is too thin, adhesion and acid resistance may deteriorate.

Next, the plating method of the present invention will be explained in detail. The plating method of the present invention can be applied as a plating method when performing plating processes such as copper plating and nickel plating. Specifically, it is preferably used for applications such as the additive method for forming metal circuits, the semi-additive method, and the additive method for producing high-definition metal masks. This is a method in which metal patterns and circuit patterns are formed by plating the exposed base material other than the parts.

For example, in a semi-additive method for producing a printed wiring board, first, a substrate in which a thin metal layer is provided on an insulating substrate is prepared as a base material. Next, a resist pattern is formed in a portion where a circuit pattern is not to be formed. Next, electrolytic plating is performed to form a plated metal layer on the exposed surface of the thin metal layer. Subsequently, the resist pattern is removed by a resist stripping process. A metal pattern/circuit pattern is then formed by (flash) etching away the thin metal layer.

Examples of base materials include metal bases such as copper, copper-based alloys (titanium-copper alloy, copper-nickel alloy, etc.); nickel; chromium; iron; tungsten; iron-based alloys such as stainless steel and 42 alloy; aluminum; amorphous alloys; material can be used.
In addition, copper-clad laminates, electroless plated substrates, electroplated substrates, catalyst-applied substrates for electroless plating, flexible copper-clad laminates, flexible stainless steel plates, multi-tier structure substrates, etc. are used in printed wiring board manufacturing, etc. can be used.

A photo method is used to form a resist pattern on a base material. In the photo method, first, a coating liquid containing a photosensitive resin composition is applied to a substrate and dried to form a photosensitive resin layer containing the photosensitive resin composition. A DFR in which a photosensitive resin layer is formed on a support (carrier film) may be prepared in advance, and the photosensitive resin layer may be transferred to the base material.

Next, pattern exposure is performed to harden the exposed areas. Next, alkaline development is performed to remove the photosensitive resin layer in non-exposed areas, which are unnecessary portions of the resist pattern, to form a resist pattern including the cured photosensitive resin layer. As the alkaline developer used for alkaline development, for example, an aqueous solution of an inorganic basic compound can be used. Examples of the inorganic basic compound include carbonates and hydroxides of lithium, sodium, potassium, etc., and a 0.1 to 3% by mass aqueous sodium carbonate solution can be preferably used.
A small amount of a surfactant, an antifoaming agent, a solvent, etc. may be appropriately mixed into the developer. Development processing methods include a dipping method, a battle method, a spray method, brushing, and scraping, with the spray method being the most suitable in terms of removal speed. The temperature of the development treatment is preferably 15 to 35°C, and the spray pressure is preferably 0.02 to 0.3 MPa.

In the present invention, the resist pattern after alkaline development may be subjected to baking treatment. By the baking treatment, the effect of improving the adhesion between the photosensitive resin layer and the base material, the effect of improving the plating resistance, etc. can be obtained. The baking temperature is preferably 80° C. or higher, and the baking time is preferably 5 minutes or longer. Furthermore, if the base material is copper or the like and is a material that easily discolors due to oxidation or the like, the baking treatment is performed at about 80°C. If the base material is made of a material that is difficult to oxidize, such as stainless steel, the temperature of the baking treatment may be 100° C. or more, and the baking treatment may be performed for a long time of 30 minutes or more. Moreover, for the purpose of preventing deformation of the photosensitive resin layer due to heat, irradiation treatment with actinic light such as ultraviolet rays may be performed before the baking treatment.

Next, the exposed portion of the base material on which the resist pattern is not formed is plated to form a metal pattern/circuit pattern. The plating method is as described above, and may be electrolytic plating, substitution type or reduction type electroless plating. Moreover, the metal (alloy) to be plated (plating metal (alloy)) is not particularly limited.

In the resist stripping process, an alkaline aqueous solution is usefully used as a resist stripping solution. Examples of basic compounds used in the resist stripping solution include inorganic basic compounds such as alkali metal silicate, alkali metal hydroxide, alkali metal phosphate, alkali metal carbonate, ammonium phosphate, and ammonium carbonate. Compounds: Examples include organic basic compounds such as ethanolamine, ethylenediamine, propanediamine, triethylenetetramine, morpholine, and tetramethylammonium hydroxide.

In the resist stripping process, in order to control the solubility of the cured photosensitive resin layer, it is necessary to adjust the concentration, temperature, spray pressure, ultrasonic conditions, etc. of the resist stripping solution. The higher the temperature of the resist stripping solution, the faster the cured photosensitive resin layer dissolves, and a temperature of 40° C. or higher is preferable. The concentration of the basic compound in the resist stripping solution is preferably a concentration suitable for solubility, and when the basic compound is sodium hydroxide, it is preferably 1 to 4% by mass. As the device, a dip treatment device, an ultrasonic device, a shower spray device, etc. can be used.

In the present invention, the photosensitive resin layer that has been cured by pattern exposure and optionally subjected to baking treatment is dissolved in the resist stripping solution when it is removed by the resist stripping solution in the resist stripping step. In the present invention, "dissolution" of the cured photosensitive resin layer means that the photosensitive resin layer is dissolved in the resist stripping solution, or that the resist stripping pieces are so fine that they cannot be visually confirmed. Refers to the state of being. The state in which the resist peeled pieces are extremely fine includes a state in which they are dispersed at the molecular aggregate level, a state in which they are dispersed as fine particles of 100 μm or less, and the like.

The present invention is also a method for manufacturing a metal pattern, characterized in that a metal pattern is formed on a base material using the above-described plating method.
It is preferable to use the above-described method in each step to form the metal pattern.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

In Tables 1 to 3, each component is as follows.

(A-1) Copolymer resin made by copolymerizing methyl methacrylate/n-butyl acrylate/methacrylic acid at a mass ratio of 64/15/21 (mass average molecular weight 40,000)

(B-1) 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer (B-2) 4,4'-bis(diethylamino)benzophenone

(C1-1) Ethylene oxide-modified pentaerythritol tetraacrylate (compound represented by general formula (i), where l+m+n+o=35)
(C2-1) Ethylene oxide-modified pentaerythritol tetraacrylate (compound represented by general formula (i), where l+m+n+o=4)

(C3-1) Pentaerythritol triacrylate (C3-2) Polyethylene glycol #600 diacrylate (number of repeats of ethylene oxide is 14)

(D-1) Dimethacrylate of ethylene oxide adduct of bisphenol A (total number of repeats of ethylene oxide is 10)

(E-1) 4-methoxyphenol

(F-1) Leuco crystal violet

Examples 1-1 to 1-6, Comparative Examples 1-1 to 1-4
Each component shown in Table 1 was mixed to obtain a photosensitive resin composition and a coating liquid. In addition, the unit of the amount of each component in Table 1 represents parts by mass.
The obtained coating liquid was applied onto a polyethylene terephthalate (PET) film (product name: R310, 16 μm thick, manufactured by Mitsubishi Chemical Corporation) using an applicator, dried at 80°C for 8 minutes, and the solvent was evaporated. , a DFR in which a photosensitive resin layer (dry film thickness: 30 μm) made of the photosensitive resin compositions of Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-4 was provided on one side of a PET film. I got it.

A stainless steel plate with a surface roughness Ra of 0.01 μm to 1 μm was subjected to surface treatments such as alkaline degreasing and acid treatment, and the photosensitivity of Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-4 was determined. A resin layer was attached. Next, it was exposed to light through a photomask having a 50 μm line and space pattern, and then the PET film was peeled off and alkaline development was performed with a 1.0% by mass sodium carbonate aqueous solution, and the photosensitive resin layer in the non-exposed area was was removed to form a resist pattern.

At that time, in the photosensitive resin layer of Comparative Example 1-1 in which the content of (C1) was more than 70% by mass with respect to the total amount of the (C) acrylate monomer, the resist pattern made of the cured photosensitive resin layer was It swelled and a 50 μm line and space pattern was detached.
On the other hand, in Examples 1-1 to 1-6, good 50 μm line and space patterns were all produced.

Next, by electrolytic plating using a nickel sulfamate (Ni) bath, a plating film is grown on the portions of the stainless steel plate not covered by the resist pattern, and a Ni metal layer is grown to a thickness of 25 μm. Formed.

At that time, in Comparative Examples 1-2 and 1-3 using photosensitive resin compositions in which the content of (C1) was less than 30% by mass based on the total amount of acrylate monomer (C), the line bottom of the resist pattern It was found that the plating solution had seeped into the resist, and there was thinning of the image at the bottom of the resist. Therefore, the Ni metal layer penetrated into the bottom of the resist, making it impossible to produce a good Ni pattern.
On the other hand, in Examples 1-1 to 1-6, good Ni patterns were all produced.

Next, in Examples 1-1 to 1-6 and Comparative Example 1-4, the resist patterns were removed by immersion in a 3% by mass aqueous sodium hydroxide solution (liquid temperature 50°C).
The resist patterns were successfully removed using the photosensitive resin compositions of Examples 1-1 to 1-6.
On the other hand, in Comparative Example 1-4 using a photosensitive resin composition in which the content of (D) was 8.8% by mass and more than 5% by mass based on the total amount of acrylate monomer (C), A problem occurred in which resist pattern residue remained between spaces.

Furthermore, as a result of immersing the peeled pieces of the photosensitive resin layers of Examples 1-1 to 1-6 in a 3% by mass aqueous sodium hydroxide solution (liquid temperature 50°C) for 3 hours, the peeled pieces could no longer be visually confirmed. . As a result, when processing the next work, there is no need to worry about "entanglement" of the peeled resist pieces between the Ni patterns.

Examples 2-1 to 2-7, Comparative Example 2-1
Each component shown in Table 2 was mixed to obtain a photosensitive resin composition and a coating liquid. In addition, the unit of the amount of each component in Table 2 represents parts by mass. Moreover, the content rate of (E) is the content rate of (E) with respect to the total amount of (A), (B), (C), and (E), and its unit is mass ppm.
The obtained coating liquid was applied onto a polyethylene terephthalate (PET) film (product name: R310, 16 μm thick, manufactured by Mitsubishi Chemical Corporation) using an applicator, dried at 80°C for 8 minutes, and the solvent was evaporated. A DFR was obtained in which a photosensitive resin layer (dry film thickness: 30 μm) containing the photosensitive resin compositions of Examples 2-1 to 2-7 and Comparative Example 2-1 was provided on one side of a PET film.

A stainless steel plate with a surface roughness Ra of 0.01 μm to 1 μm was subjected to surface treatments such as alkaline degreasing and acid treatment, and the photosensitive resin layers of Examples 2-1 to 2-7 and Comparative Example 2-1 were attached. I attached it.

Next, it was exposed to light through a photomask having a circular dot pattern with diameters of 200, 150, 100, and 80 μm, and then the PET film was peeled off and alkaline development was performed with a 1.0 mass% sodium carbonate aqueous solution. , the photosensitive resin layer in non-exposed areas was removed to form a resist pattern.

At this time, in Comparative Example 2-1 which did not contain (C1) as the (C) acrylate monomer, more than half of the dot pattern with a diameter of 150 μm or less was lost during the development process.
Further, in Example 2-7 in which the content of (E) was less than 400 ppm, the dot pattern with a diameter of 100 μm or more remained on the substrate during the development process, but the dot pattern with a diameter of 80 μm was slightly lost.

On the other hand, in Examples 2-1 to 2-6, all circular dot patterns with diameters of 200, 150, 100, and 80 μm remained on the substrate even after development, showing high adhesion.

Next, by electrolytic plating using a nickel sulfamate (Ni) bath, a plating film is grown on the portions of the stainless steel plate not covered by the resist pattern, and a Ni metal layer is grown to a thickness of 25 μm. Formed.

At this time, in Comparative Example 2-1, it was found that in a circular dot pattern with a diameter of 200 μm, the plating solution permeated and there was thinning of the image at the bottom of the resist. Therefore, the Ni metal layer penetrated under the resist, and a good Ni metal layer could not be formed.
On the other hand, in Examples 2-1 to 2-7, there was no seepage of the plating solution and a good Ni metal layer was formed.

Next, the resist pattern was removed by immersion in a 3% by mass aqueous sodium hydroxide solution (liquid temperature: 50°C). The resist patterns formed by the photosensitive resin compositions of Examples 2-1 to 2-7 and Comparative Example 2-1 were successfully peeled off.

Furthermore, as a result of immersing the peeled pieces of the photosensitive resin layer of Examples 2-1 to 2-7 and Comparative Example 2-1 in a 3% by mass sodium hydroxide aqueous solution (liquid temperature 50°C) for 3 hours, the peeled pieces were It can no longer be visually confirmed. As a result, when processing the next workpiece, there is no need to worry about the peeled resist pieces becoming entangled between the Ni patterns.

Examples 3-1 to 3-7, Comparative Examples 3-1 to 3-2
The components shown in Table 3 were mixed to obtain a photosensitive resin composition and a coating liquid. Note that the unit of the amount of each component in Table 3 is parts by mass. The obtained coating liquid was applied onto a polyethylene terephthalate (PET) film (product name: R310, 16 μm thick, manufactured by Mitsubishi Chemical Corporation) using an applicator, dried at 80°C for 8 minutes, and the solvent was evaporated. , a DFR in which a photosensitive resin layer (dry film thickness: 50 μm) made of the photosensitive resin compositions of Examples 3-1 to 3-7 and Comparative Examples 3-1 to 3-2 was provided on one side of a PET film. Obtained.

A stainless steel plate with a surface roughness Ra of 0.01 μm to 1 μm was subjected to surface treatments such as alkaline degreasing and acid treatment, and the photosensitivity of Examples 3-1 to 3-7 and Comparative Examples 3-1 to 3-2 was A resin layer was attached.

Next, it was exposed to light through a photomask having a circular dot pattern with diameters of 100, 80, 70, and 60 μm, and then the PFT film was peeled off and alkaline development was performed using a 1.0 mass% sodium carbonate aqueous solution. , the photosensitive resin layer in non-exposed areas was removed to form a resist pattern.

At this time, the photosensitive resin layer of Example 3-7 in which the content of (F) was less than 0.15% by mass had low sensitivity to exposure, and the same exposure amount as Examples 3-1 to 3-6 The curing of the resist did not progress sufficiently. Therefore, as a result of observing the resist image, more than half of the dot patterns with a diameter of 80 μm or less were lost, but the dot patterns with a diameter of 100 μm remained.

In addition, the photosensitive resin layers of Comparative Examples 3-1 to 3-2 that do not contain (C1) as the (C) acrylate monomer have weak adhesion to the base material, and the dot patterns are halved in all diameters during the development process. More than that was lost.

On the other hand, in Examples 3-1 to 3-6, the dot patterns remained on the substrate at all diameters even after development, showing high adhesion.

Next, in Examples 3-1 to 3-7, a plating film was grown on the portion not covered by the resist pattern on the stainless steel plate by electrolytic plating using a nickel sulfamate (Ni) bath. A Ni metal layer was formed to have a thickness of 25 μm.

At this time, in Examples 3-1 to 3-7, there was no seepage of the plating solution and a good Ni metal layer was formed.

Next, the resist pattern was removed by immersion in a 3% by mass aqueous sodium hydroxide solution (solution temperature: 50° C.). The resist patterns formed by the photosensitive resin compositions of Examples 3-1 to 3-7 were successfully peeled off.

Furthermore, as a result of immersing the peeled pieces of the photosensitive resin layers of Examples 3-1 to 3-7 in a 3% by mass aqueous sodium hydroxide solution (liquid temperature 50°C) for 3 hours, the peeled pieces could no longer be visually confirmed. . As a result, when processing the next workpiece, there is no concern that the peeled resist pieces will become entangled between the Ni patterns.

INDUSTRIAL APPLICABILITY The present invention can be widely used in the field of producing and using photosensitive resin compositions. In particular, the production and use of photosensitive resin compositions for forming resist patterns used during plating in the production of printed wiring boards, lead frames, metal masks, shadow masks, semiconductor packages, electrode members, electromagnetic shields, etc. Can be widely used in various fields.

Claims (6)

Contains (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) an acrylate monomer, and (E) a polymerization inhibitor,
The content of (D) methacrylate monomer is 0 to 5% by mass with respect to (C) acrylate monomer,
(C) As the acrylate monomer, (C1) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by general formula (i), where l+m+n+o=24 to 48) and (C2) ethylene oxide-modified pentaerythritol tetraacrylate (general formula (i), where l + m + n + o = 4 to 8) ,
(C) The content of (C1) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by general formula (i), where l + m + n + o = 24 to 48) is 35 to 70% by mass, based on the total amount of acrylate monomer. ,
(C) The content of (C2) ethylene oxide-modified pentaerythritol tetraacrylate (a compound represented by general formula (i), where l + m + n + o = 4 to 8) is 30 to 60% by mass, based on the total amount of acrylate monomer. ,
The content of (E) polymerization inhibitor is 400 to 1000 ppm based on the total amount of (A) alkali-soluble resin, (B) photopolymerization initiator, (C) acrylate monomer, and (E) polymerization inhibitor. Characteristic photosensitive resin composition.

The photosensitive resin composition according to claim 1, wherein the polymerization inhibitor (E) is a hydroquinone. The polymerization inhibitor (E) is hydroquinone, methylhydroquinone, 4-methoxyphenol, 2,5-di-tert-butylhydroquinone, tert-butylhydroquinone, 2,6-di-tert-butyl-p-cresol, p- -Benzoquinone, methyl-p-benzoquinone, tert-butyl-p-benzoquinone, catechol, 4-tert-butylcatechol, 3-methoxycatechol, pyrogallol, picric acid, phenoxazine, 3,7-bis(diethylamino)phenoxazine- selected from the group consisting of 5-ium perchlorate, 5-amino-9-(dimethylamino)-10-methylbenzo[a]phenoxazin-7-ium chloride, copper chloride and N-nitrosophenylhydroxylamine aluminum salt The photosensitive resin composition according to claim 1, which is one or more kinds of compounds. The photosensitive resin composition contains (F) a photocoloring agent, and based on the total amount of (A) alkali-soluble resin, (B) photopolymerization initiator, (C) acrylate monomer, and (F) photocoloring agent, The photosensitive resin composition according to any one of claims 1 to 3, wherein the content of the photochromic agent (F) is 0.15 to 1.5% by mass. A photosensitive resin layer containing the photosensitive resin composition according to any one of claims 1 to 4 is formed on a base material, then pattern exposure is performed to harden the exposed area, and then Plating characterized by performing alkaline development to remove the photosensitive resin layer in non-exposed areas to form a resist pattern containing a cured photosensitive resin layer, and then plating the exposed base material. Method. A method for manufacturing a metal pattern, comprising forming a metal pattern on a base material using the plating method according to claim 5 .