JPH05107760A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain developability by an aq. alkaline soln. and to enhance sensitivity and resolution by constituting the above compsn. of a binder polymer, compd. and a copolymer of methyrol(meta)acryl amide deriv. which are respectively specific. CONSTITUTION:This photosensitive resin compsn. consists of the film formable binder polymer which is soluble or swells in the aq. alkaline soln., the compd. which generates a strong acid when irradiated with active rays, and the polymer contg. the repeating unit expressed by formula I. In the formula I, R<1> denotes a hydrogen or 1 to 3C alkyl group; R<2> denotes hydrogen, 1 to 6C alkyl group or 1 to 6C hydroxyalkyl group. The compd. which generates the strong acid when irradiated with the active energy is the compd. which generates the strong acid when this compsn. is irradiated with the active energy rays and which enhances the solubility in the aq. alkaline soln. and imparts developability thereto.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive resin composition. In particular, the present invention relates to a photosensitive resin composition suitable as a resist used when manufacturing a printed wiring board.

[0002]

2. Description of the Related Art A method (hereinafter referred to as image reversal) is known in which a positive type photosensitive resin composition whose exposed portion becomes soluble in a developing solution upon irradiation with active energy rays is used for forming a negative image. However, the resist produced by the image reversal method cannot be used as a resist such as an electroless plating resist or a solder resist for a printed wiring board. This resist is exposed to, for example, an electroless copper plating solution having a pH of about 12 and 70 ° C. for a long period of time, and thus it is required to have resistance to an electroless plating solution that can withstand a high alkaline aqueous solution. Further, in recent years, circuits have become finer with the increase in density of printed wiring boards, and resists are required to have excellent sensitivity, resolution, and developability. Examples of the photosensitive resin composition for image reversal include, for example, the binders described in JP-A-63-271346, which are insoluble in water and may be used in an alkaline aqueous solution, 1,2-
A photosensitive resin composition comprising a quinonediazide or a compound which generates an acid upon exposure, a urethane / formaldehyde condensation product, or a binder which is insoluble in water and soluble in an aqueous alkali solution, as described in JP-A-60-39642. A photosensitive resin composition comprising quinonediazide and hexamethylolmelamine hexamethyl ether is known.

[0003]

However, although the above-mentioned conventional photosensitive resin composition is suitable for use as a printing plate, it is used as a resist which requires resistance to electroless plating solution, sensitivity, resolution and developability. Can not. The present invention provides a photosensitive resin composition used for negative image formation by image reversal, which can be developed with an alkaline aqueous solution and is excellent in sensitivity, resolution and resistance to electroless plating solution.

[0004]

[Means for Solving the Problems] A film-forming polymer which is soluble or swellable in an alkaline aqueous solution, B. A compound that generates a strong acid upon irradiation with an active energy ray, and C.I. The following general formula 2

[0005]

[Chemical 2]

(However, R ¹ is hydrogen or has 1 carbon atom.
Represents an alkyl group having 3 to 3 carbon atoms, R ² hydrogen, an alkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms. This can be achieved by a photosensitive resin composition composed of a polymer containing a repeating unit represented by

A. The film-forming binder polymer which is soluble or swellable in the alkaline aqueous solution serves as a binder for the cured product of the photosensitive resin composition and imparts developability to the alkaline aqueous solution to the photosensitive resin composition. Examples of such a polymer include a polymer having a carboxy group, a polymer having an anhydrous carboxy group, polyvinylphenols, polyvinyl alcohols, novolac resins, and a (meth) acrylate copolymer having a hydroxy group [(meth) acrylate is an acrylate or Represents methacrylate. The same applies below. ] Etc. are mentioned.

As the polymer having a carboxy group,
A monomer having a carboxy group and a (meth) acrylic acid ester [(meth) acrylic acid represents acrylic acid or methacrylic acid. The same applies below. ], Copolymers with vinyl monomers such as styrenes and acrylonitriles. The weight average molecular weight is preferably 5,000 to 200,000.

Specific examples of the monomer having a carboxy group include (meth) acrylic acid, itaconic acid, crotonic acid, sorbic acid, fumaric acid, propiolic acid, maleic acid and cinnamic acid.

Specific examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate and isobutyl. (Meth) acrylate, sec
-Butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth ) Acrylate, nonyl (meth) acrylate, decyl (meth)
Acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate,
Oleyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclopentanyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, naphthyl (meth) acrylate and other alkyl or aryl (meth) acrylates, methoxyethyl ( (Meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxytetraethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) Acrylate, phenoxyethyl (meth) acrylate,
Phenoxydiethylene glycol (meth) acrylate, phenoxydiethoxy (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, phenoxyhexaethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, ethoxy polyethylene glycol (meth)
Polyether diol monoether (meth) acrylate such as acrylate, nonylphenoxy polyethylene glycol (meth) acrylate, nonylphenoxy polypropylene glycol (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-chloroisopropyl (meth) acrylate, 2- Bromoethyl (meta)
Acrylate, 2,3-dibromopropyl (meth) acrylate, tribromophenyl (meth) acrylate,
Halogenated alkyl (meth) acrylates such as trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate , 2-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-
Hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2
In addition to hydroxy group-containing (meth) acrylates such as -hydroxypropyl (meth) acrylate and 3-chloro-2-hydroxybutyl (meth) acrylate,
Examples thereof include glycidyl (meth) acrylate, 2-cyanoethyl acrylate, and tetrahydrofurfuryl (meth) acrylate.

Specific examples of styrenes include styrene,
Examples include α-methylstyrene, p-isopropenylstyrene, vinyltoluene and the like.

Specific examples of acrylonitriles include acrylonitrile and α-methylacrylonitrile.

In addition to the above vinyl monomers, vinyl formate, vinyl acetate, vinyl butyrate, vinyl propionate, vinyl laurate, vinyl benzoate, vinyl benzenesulfonate, vinyl isopropyl ether, vinylpyrrolidone, vinyl chloride and the like can be mentioned.

Examples of the polymer having an anhydrous carboxy group include a copolymer of a monomer having an anhydrous carboxy group and a vinyl monomer such as (meth) acrylic acid ester, styrenes and acrylonitriles. The weight average molecular weight is preferably 2000 to 100000.

Specific examples of the monomer having a carboxy anhydride group include 2,3-dichloromaleic anhydride and 2 anhydride.
-Chloromaleic acid, citraconic anhydride, dodecenylsuccinic anhydride, nonenylsuccinic anhydride, bromomaleic anhydride, maleic anhydride and the like can be mentioned.

The polyvinylphenols include homopolymers of vinylphenol or vinyl monomers such as vinylphenol and (meth) acrylic acid ester, styrenes, acrylonitriles, monomers having a carboxy group, and monomers having an anhydrous carboxy group. Copolymers of Specifically, Marzen Resin M,
Maruzen resin MB, resin CMM, resin CHM, resin MAA, resin MS-2, resin MS-3 [above,
Maruzen Petrochemical Co., Ltd.] and the like. The weight average molecular weight of polyvinylphenols is 2,000 to 50,000.
Is preferred.

Examples of polyvinyl alcohols include fully saponified vinyl acetate polymers and partially saponified vinyl acetate polymers. The weight average molecular weight of polyvinyl alcohol is preferably 5,000 to 50,000.

Examples of novolac resins include phenol novolac resins and cresol novolac resins which are swellable or soluble in an alkaline aqueous solution. The weight average molecular weight of the novolac resin is preferably 500 to 5000.

Examples of the (meth) acrylate copolymer having a hydroxy group include a mono (meth) acrylate having a hydroxy group and a (meth) acrylic acid ester, styrenes, acrylonitriles, a monomer having a carboxy group, and an anhydrous carboxy group. Examples thereof include a copolymer with a vinyl monomer such as a monomer having the same. The weight average molecular weight of the copolymer is preferably 5,000 to 100,000.

As specific examples of the mono (meth) acrylate of the hydroxy compound, those mentioned in the specific examples of the (meth) acrylic acid ester can be used.

The content of the binder polymer in the photosensitive resin composition is preferably 20 to 80% by weight. 20% by weight
If it is less than the range, developability is deteriorated and the cured product becomes hard and brittle. In addition, the viscosity decreases, and there is a risk of edge fusion when the photosensitive resin composition is laminated. If it exceeds 80% by weight, the photosensitive resin composition is easily dissolved in the developing solution, the adhesion is lowered and the resolution is deteriorated. Two or more binder polymers may be used in combination.

B. The compound that generates a strong acid upon irradiation with an active energy ray is a compound that generates a strong acid when the composition of the present invention is irradiated with an active energy ray, enhances solubility in an alkaline aqueous solution, and imparts developability. is there. In addition, after the development, when the heat treatment is performed after irradiating the unexposed portion with the active energy ray, the generated strong acid serves as a catalyst, and C.I. Of the polymer containing the repeating unit represented by the general formula (2), promotes a crosslinking reaction by heat to form a strong bond. Examples of such compounds include 1,2-quinonediazidesulfonic acid 4-esters; 1,2-quinonediazidesulfonic acid 4-amides; 1,2-quinonediazidecarboxylic acid 4-esters; 1,2-quinonediazide Carboxylic acid 4-amides; 1,2-quinonediazide sulfonic acid 5-esters; s-triazine derivative; diazonium complexed with an acid such as tetrafluoroboric acid, hexafluorophosphoric acid, or hexafluoroantimonic acid Examples thereof include compounds, phosphonium compounds, sulfonium compounds, iodonium compounds, and the like.

The content of the compound that generates a strong acid upon irradiation with active energy rays in the photosensitive resin composition is 5% by weight to
50% by weight is preferred. If it is less than 5% by weight, the developability is deteriorated, and if it exceeds 50% by weight, sufficient resistance to electroless plating solution cannot be obtained.

C. The polymer containing a repeating unit represented by the general formula 2 of B.I. A strong acid generated from the compound of (1) as a catalyst causes a cross-linking reaction to form a strong bond to improve resist adhesion and resistance to electroless plating solution. Therefore, the pattern formed using the photosensitive resin composition of the present invention has excellent resolution. Examples of such a polymer include a copolymer of a monomer represented by the following general formula 3 and a vinyl monomer such as (meth) acrylic acid ester, styrenes and acrylonitriles. Weight average molecular weight is 5,000 to 20
0000 is preferable.

[0025]

[Chemical 3]

(However, R ¹ is hydrogen or has 1 carbon atom.
Represents an alkyl group having 3 to 3 carbon atoms, R ² hydrogen, an alkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms. )

Specific examples of the monomer represented by the general formula 3 include N-methylol acrylamide, Nn-butoxymethyl acrylamide and Nn-propoxymethyl acrylamide.

Vinyl monomers such as (meth) acrylic acid esters, styrenes, acrylonitriles, etc. As the monomer having an ethylenically unsaturated bond, the above-mentioned A. The specific examples of the film-forming binder polymer which is soluble or swellable in the alkaline aqueous solution are mentioned. The content of the polymer containing the repeating unit represented by the general formula 2 in the photosensitive resin composition is preferably 10 to 60% by weight. If it is less than 10% by weight, the adhesion to the substrate surface will be deteriorated and the resistance to electroless copper plating solution will be poor. If it exceeds 60% by weight, the developability will deteriorate.

The photosensitive resin composition of the present invention may optionally contain a crosslinking catalyst, a thermal polymerization inhibitor, a filler, a dye, a pigment, a heat stabilizer, an adhesion promoter, a plasticizer, a defoaming agent, a leveling agent,
An anti-sagging agent, a flame retardant and the like may be added in the range of 0.1 to 50% by weight.

The photosensitive resin composition of the present invention can be dissolved in a solvent and used as a liquid resist. When it is used as a liquid resist, it can be directly applied on a support by a method such as a dipping method, a spray method, a flow coating method or a screen printing method to form a photosensitive layer having a thickness of 10 to 150 μm. The solvent used at this time may be a solvent that dissolves the photosensitive resin composition, and examples thereof include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, propylene glycol methyl ether, propylene glycol. Glycol ethers such as ethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol methyl ether acetate, glycol esters such as propylene glycol ethyl ether acetate, alcohols such as methanol and ethanol, dichloromethane, 1,1,1-trichloroethane Examples include chlorine-containing aliphatic solvents such as, and aromatic hydrocarbon solvents such as toluene and xylene.
These solvents may be used alone or as a mixture.

The photosensitive resin composition of the present invention can be used as a dry film. As the supporting film when used as a dry film, for example, a film made of polyethylene terephthalate, polypropylene, polyethylene or the like is used, and a polyethylene terephthalate film is particularly preferable. The thickness of the film is preferably 5 to 100 μm. Further, one of these films may be used as a protective film for the photosensitive layer. The solvent described above can be used as a solvent for making the photosensitive resin composition into a liquid state when producing a dry film. A liquid photosensitive resin composition is uniformly applied on a support film, and the solvent is removed by heat drying or hot air drying to form a photosensitive layer. The thickness of the photosensitive layer is preferably 10 to 100 μm. Next, the dry film in which the photosensitive layer is formed on the support film is kept as it is, or a protective film is laminated on the photosensitive layer and wound up in a roll shape for storage.

Next, a method of using the photosensitive resin composition of the present invention will be described. 1) by applying a liquid resist on a substrate by the above-mentioned method and removing the solvent by heat drying or hot air drying, or 2) laminating a photosensitive layer on the substrate by a dry film by a usual laminating method. Then, a photosensitive layer of the photosensitive resin composition of the present invention is formed on a substrate. After that, the photosensitive layer is irradiated with an active energy ray through a negative mask or a positive mask. Examples of active energy rays include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, and ultraviolet rays using a tungsten lamp as a light source, an argon laser, a helium cadmium laser,
A krypton laser or the like is used.

Then, the exposed portion of the photosensitive layer is removed by a method such as spraying, dipping or brushing with a developing solution. The developer is, for example, lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium phosphate, potassium phosphate, sodium pyrophosphate. Aqueous solutions of potassium pyrophosphate, sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, ammonia, monoethanolamine, diethanolamine, triethanolamine, monomethylamine, dimethylamine, triethylamine and the like are used. Further, an antifoaming agent, an organic solvent, etc. may be added to the developing solution.

After development, the developing solution is removed by washing with water, irradiation with active energy rays and heat treatment at 100 to 200 ° C. are carried out. The pattern-formed cured product thus obtained has excellent electroless plating solution resistance.

[0035]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to the following examples.

Examples 1 to 4 and Comparative Examples 1 to 2 Photosensitive resin compositions having the compositions shown in Table 1 were prepared. In addition,
The compounding ratio described below is% by weight.

[0037]

[Table 1]

* 1: Weight ratio = 45/30/25 * 2: SMA resin 1000 manufactured by ARCO Chemical Co., Ltd. * 3: 2,3,4-trihydroxybenzophenone-
1,2-naphthoquinonediazide-4-sulfonic acid ester * 4: 4- (2-ethylhexanoyl) resorcinol-1,2-naphthoquinonediazide-4-sulfonic acid ester * 5: weight ratio = 80/20

This photosensitive resin composition was coated on a polyethylene terephthalate film having a thickness of 25 μm, and the temperature was 80 ° C.
The film was heated and dried for 10 minutes with a normal air dryer to obtain a photosensitive layer having a thickness of 40 μm. This photosensitive layer was covered with a polyethylene film having a thickness of 20 μm to prepare a dry film. Then, while peeling off the polyethylene film, a photosensitive layer was laminated on a printed board to which an electroless copper plating catalyst was applied by a laminating device. Next, through a positive mask, exposure was performed at 250 mJ / cm ² using a high pressure mercury lamp. After exposure,
After leaving it for 30 minutes at room temperature, spray development was performed for 100 seconds at 20 ° C. using a 1% sodium carbonate aqueous solution. After the development, the developing solution remaining on the printed board was removed by washing with water, and after drying, exposure was performed with a high pressure mercury lamp at 5 J / cm ² . Then, heat treatment was performed at 150 ° C. for 60 minutes to perform heat curing.

The performance of the resist thus obtained on the printed board was evaluated by the following method. The results are shown in Table 2. Sensitivity A step wedge with an optical density difference of 0.15 was used as a positive mask, and the number of steps of the positive image removed after development was taken as the sensitivity. Resolution The minimum width (μm) of the line / space (= 1/1) formed after development was taken as the resolution. Adhesiveness Adhesiveness is defined as the minimum width (μm) at which one independent pattern is formed without breaking or meandering when the interval between two adjacent patterns is 400 μm. Resistance to Electroless Plating Solution The resist after heat curing was immersed in an electroless copper plating solution having a pH of 12 and 70 ° C. for 15 hours, and the appearance was observed.

[0041]

[Table 2]

○: no change ×: blister

[0043]

The present invention has the following effects. (1) Excellent resistance to electroless plating solution. A resist using a conventional positive-type photosensitive resin composition is inferior in adhesiveness to a substrate surface and alkali resistance.
When immersed in an electroless copper plating solution at 0 ° C. and pH 12, phenomena such as peeling and swelling from the substrate surface appear. The photosensitive resin composition of the present invention provides a resist having excellent electroless plating solution resistance by forming a strong bond by thermal crosslinking to improve adhesion to a substrate surface, and alkali resistance. You can

(2) It has excellent sensitivity and resolution. The photosensitive resin composition of the present invention can provide a resist having excellent sensitivity and resolution by using a binder polymer having excellent developability.

(3) Excellent developability with an alkaline aqueous solution. The photosensitive resin composition of the present invention, by the action of a strong acid generated by irradiation with active energy rays, and by using a binder polymer having excellent developability with an alkaline aqueous solution, a resist with excellent developability with an alkaline aqueous solution is obtained. Can be provided.

Because of the above effects, the photosensitive resin composition of the present invention is used in addition to a solder resist used in the production of printed wiring boards, a plating resist in the full additive method, an etching resist, an interlayer insulating material, etc.
It is suitable for applications such as fine processing of metals, PS plates, photosensitive liquids for screen printing and resist inks.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location G03F 7/029 9019-2H 7/038 505 7124-2H H01L 21/027 H05K 3/06 H 6921- 4E

Claims (1)

[Claims] 1. A. A film-forming binder polymer soluble or swelling in an alkaline aqueous solution, B. A compound that generates a strong acid upon irradiation with an active energy ray, and C.I. A polymer containing a repeating unit represented by the following general formula 1, (However, R ¹ represents hydrogen or an alkyl group having 1 to 3 carbon atoms, R ² represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms.)
A photosensitive resin composition comprising: