JPH0823696B2 - Alkali developable photosensitive resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an alkali-developable photosensitive resin composition, and more specifically, it comprises an alkali-developable photosensitive resin composition on a printed wiring board. The present invention relates to an alkali-development-type photosensitive resin composition which can be alkali-developed after exposure by forming a film, and can be suitably used as a solder resist and an electroless gold plating resist in the exposure-cured portion, and as a solder mask. It is a thing.

(Prior Art) In recent years, as the density of ICs and LSIs has been increasing, the density of printed wiring boards on which they are mounted has also been increasing, and lead wires have been miniaturized or parts without lead wires have been replaced. We are moving to adopting the surface mounting method that mounts directly on the surface of the board.

By the way, when forming a solder resist on a printed wiring board, conventionally, a thermosetting type resist ink was printed by a screen printing method, and the transfer part was heat-cured. However, the fact is that this method cannot fully meet the demand for higher density, and a method for obtaining a solder resist using the principle of photography has been developed. Along with this, the development of photoresist ink has been studied. Has been done.
Further, in terms of work environment and processing cost, photoresist inks have been proposed that can be developed with a weak alkaline aqueous solution such as an aqueous solution of sodium carbonate, instead of the type developed with an organic solvent.

For example, JP-A-61-243,869 and JP-A-63-278,052 disclose a resist ink composition containing a resin component having a novolak type or bisphenol A type epoxy resin skeleton and developable in a weak alkaline aqueous solution or a photosensitive material. A film coating composition is disclosed. Further, in JP-A-61-158,710, JP-A-62-285,903 and JP-A-63-11,930, a hydroxyalkylene acrylate or hydroxyalkylene methacrylate is opened in a copolymer of maleic anhydride and styrene. There is disclosed an alkali developing type resin composition having a base polymer added thereto.

Also, as the circuit density of printed wiring boards increases,
When it is difficult to take lead wires by design, a method of connecting from a part of the circuit instead of from the terminal part is adopted. In this case, in order to obtain a contact and prevent corrosion of copper that constitutes the circuit. In addition, electroless gold plating is applied.

However, since gold is expensive, it is desirable to perform plating by applying an electroless gold plating resist in order to avoid unnecessary adhesion of gold to the copper circuit portion and land portion (also, this electroless gold plating resist is used. Can be used as a solder resist, and it is also desirable to double as a solder mask in the process). However, when the composition disclosed in the above publication is used as an electroless gold plating resist also as a solder mask, it cannot withstand the conditions of gold plating under high temperature and acidity, and it may be whitened after the treatment. However, when it also functions as a solder mask, there is a problem in that the adhesion between the mask and the substrate decreases. Therefore, the electroless gold plating process must be performed before the solder mask is formed.

(Problems to be Solved by the Invention) In view of the above situation, an object of the present invention is to carry out alkali development, which can be suitably used as a solder resist and an electroless gold plating resist, and further as a solder mask. A type photosensitive resin composition is provided.

(Means for Solving the Problems) As a result of intensive studies for solving the above problems, the present inventors have found that the above problems can be achieved by using a specific photopolymerizable compound together with an epoxy compound. Reached

 That is, the gist of the present invention is as follows.

It consists of the following components (A), (B) and (C),
The ratio of the component (B) to 100 parts by weight of the component (A) is 5 to 1
An alkali-developable photosensitive resin composition in which the amount of component (C) is 0.1 to 30 parts by weight, which is 00 parts by weight.

Component (A): (a) A compound having at least two epoxy groups is reacted with (b) an alkaline acid or methacrylic acid and (c) a monovalent saturated aliphatic carboxylic acid or a monovalent aromatic carboxylic acid. A photopolymerizable unsaturated compound obtained by reacting the reaction product thus obtained with (d) a polybasic acid anhydride.

Component (B): a compound having at least one epoxy group.

Component (C): Photopolymerization initiator or sensitizer.

 The present invention will be described in detail below.

First, each component constituting the alkali developing type photosensitive resin composition of the present invention will be described.

Component (A): (a) compound having at least two epoxy groups, (b) alkaline acid or methacrylic acid [hereinafter referred to as (meth) acrylate] and (c) monovalent saturated aliphatic carboxylic acid or monovalent (A) in the photopolymerizable unsaturated compound obtained by reacting (d) a polybasic acid anhydride with a reaction product obtained by reacting with an aromatic carboxylic acid
As a compound having at least two epoxy groups,
Epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, novolac type epoxy resin, alicyclic epoxy resin, diglycidyl isocyanurate, triglycidyl isocyanurate, biphenyl-4,4'- Diglycidyl ether, 3,3 ′, 5,5′-tetramethylbiphenyl-4,
Examples thereof include compounds having an epoxy group such as 4'-diglycidyl ether, glycidyl methacrylate homopolymers and polymers having glycidyl methacrylate such as glycidyl methacrylate / styrene copolymers.

Among these, preferred are compounds having an epoxy group represented by the following general formula [1] and general formula [2].

In the formula, R ₁ and R ₂ are a hydrogen atom or a methyl group, and Y is a hydrogen atom or a bromine atom. n represents the degree of polymerization and is an integer of 1 to 30, preferably 5 to 10. Examples of the compound having an epoxy group represented by the formula [1] include bisphenol A type epoxy resin and bisphenol F type epoxy resin.

In the formula, R ₃ , R ₄ and R ₅ are groups selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms and a halogen atom, m
Represents the degree of polymerization and is an integer of 2 to 30, preferably 5 to 10.
Examples of the compound having an epoxy group represented by the formula [2] include novolac type epoxy resin.

Further, as the (c) monovalent saturated aliphatic carboxylic acid or monovalent aromatic carboxylic acid constituting the component (A),
Formic acid, acetic acid, propionic acid, n-butyric acid, isobutyric acid, valeric acid, trimethylacetic acid, caproic acid, n-heptanoic acid,
Monovalent saturated aliphatic carboxylic acids such as caprylic acid, pelargonic acid, methoxyacetic acid, palmitic acid, stearic acid and benzoic acid, alkylbenzoic acid, alkylaminobenzoic acid, halogenated benzoic acid, phenylacetic acid, anisic acid, benzoylbenzoic acid Examples thereof include monovalent aromatic carboxylic acids such as acid and naphthoic acid.

Examples of the (d) polybasic acid anhydride constituting the component (A) include maleic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, tetrapropenyl succinic anhydride, phthalic anhydride, and hexahydrophthalic acid. Acid anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-ethylhexahydrophthalic anhydride, 4-ethylhexahydrophthalic anhydride, 3-propylhexahydrophthalic acid Acid anhydride, 3-isopropylhexahydrophthalic anhydride, 4-propylhexahydrophthalic anhydride, 4-isopropylhexahydrophthalic anhydride, 3
-Methyltetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, 3-ethyltetrahydrophthalic anhydride, 4-ethyltetrahydrophthalic anhydride, 3-propyltetrahydrophthalic anhydride, 3-isopropyltetrahydrophthalic acid An anhydride, 4-propyltetrahydrophthalic anhydride, 4-isopropyltetrahydrophthalic anhydride and the like can be mentioned.

The photopolymerizable unsaturated compound which is the component (A) in the present invention can be produced, for example, as follows. That is, (a) a compound having at least two epoxy groups is dissolved in an ethylene oxide solvent such as cellosolve acetate, and (b) (meth) acrylic acid and (c) a monovalent saturated aliphatic carboxylic acid or A monovalent aromatic carboxylic acid and, if necessary, a reaction accelerator of an acid and an epoxy group are added in an amount of 0.2 to 2% by weight, and the mixture is reacted at 80 to 120 ° C for 2 to 8 hours. Then, (d) polybasic acid anhydride is added to this reaction product, and the reaction product is reacted at 80 to 120 ° C. for 2 to 4 hours to obtain the desired product. At this time, these raw materials are It is preferable to react within the range. If this value exceeds 1, the acid may become excessive and cause wiring corrosion. If this value is less than 0.8, the coating adhesion and photosensitivity may be insufficient, and the storage stability of the photopolymerizable unsaturated compound obtained by reacting a polybasic acid anhydride will be poor. Tends to decline. Further, the reaction ratio of (b) and (c) is preferably selected within the range of the number of moles of (b): the number of moles of (c) = 19: 1 to 1: 1. If reacted outside this range, the adhesion or photosensitivity of the coating film tends to decrease.

The amount of polybasic acid anhydride (d) to be added is It is preferable to react within the range. If this value exceeds 1, the acid anhydride may become excessive, which may cause corrosion of the wiring, and the stability of the product tends to decrease.
On the other hand, if this value is less than 0.5, the content of carboxyl groups per unit weight becomes low, so that the developability with respect to an alkaline aqueous solution tends to be lowered.

The compound having at least one epoxy group which is the component (B) constituting the resin composition of the present invention is added for the purpose of heat curing the resin composition of the present invention. Examples of the component (B) include epoxy resins such as the bisphenol S type epoxy resin, alicyclic epoxy resin, phenylglycidyl ether, p, etc. other than the epoxy resin represented by the general formula [1] or [2]. Examples thereof include compounds having an epoxy group such as butyl phenyl glycidyl ether, cresyl glycidyl ether, diglycidyl isocyanurate, triglycidyl isocyanurate, allyl glycidyl ether, and glycidyl methacrylate.

The photopolymerization initiator or sensitizer, which is the component (C) that constitutes the resin composition of the present invention, acts on the component (A) and the photopolymerizable monomer or oligomer that is blended if necessary, to generate light. It initiates polymerization. Like this (C)
Examples of the component include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butyltrichloroacetone. Acetophenones such as phenone, benzophenone, 2-chlorobenzophenone, p, p'-dichlorobenzophenone, p, p'-bisdimethylaminobenzophenone (also called Michler's ketone), p, p'-bisdiethylaminobenzophene Benzophenones such as non, 3,3'4,4'-tetra (tert-butylperoxycarbonyl) benzophenone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin-n- Benzo such as butyl ether N'eteru such,
Benzyl dimethyl ketal, tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide,
Sulfur compounds such as thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, and 2-methylthioxanthone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone Anthraquinones such as 2,2,3-diphenylanthraquinone, organic peroxides such as azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, cumene peroxide, 2,4,5-triaryl Thiol compounds such as imidazole dimer, riboflavin tetrabutyrate, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2,4,6-tris (trichloromethyl)-
Examples thereof include organic halogen compounds such as s-triazine, 2,2,2-tribromoethanol and tribromomethylphenyl sulfone. These compounds can also be used in combination of two or more kinds. Although it does not act as a photopolymerization initiator itself, when used in combination with the above compound,
It is also possible to add a compound capable of increasing the ability of the photopolymerization initiator. Examples of such compounds include tertiary amines such as triethanolamine, which are effective when used in combination with benzophenone. The alkali-developable photosensitive resin composition of the present invention is A)
Consisting of a component, a component (B) and a component (C),
The mixing ratio of each component in this resin composition is such that (B) component is 5 to 100 parts by weight, preferably 10 to 80 parts by weight, and (A) component is 100 parts by weight with respect to 100 parts by weight of (A) component. (C) component is 0.1 to 30 parts by weight, preferably 1 to 30 parts by weight.

When the blending ratio of the component (B) is less than 5 parts by weight relative to 100 parts by weight of the component (A), the curability of the resin composition of the present invention by heating is lowered. On the other hand, if the amount exceeds 100 parts by weight, the photopolymerization rate becomes slow and the sensitivity is lowered, or development with a weak alkaline aqueous solution becomes difficult.

On the other hand, if the mixing ratio of the component (C) to the component (A) is less than 0.1 parts by weight, the photopolymerization rate becomes slow and the sensitivity is lowered. If the amount exceeds 30 parts by weight, it is difficult for light to reach the substrate, resulting in poor adhesion between the substrate and the resin.

The alkali-developable photosensitive resin composition of the present invention can be suitably used as a solder resist, an electroless gold plating resist, and a solder mask for printed wiring boards as described below. For example, the alkali-developable photosensitive resin composition of the present invention is dissolved in a solvent and applied on the surface of a printed wiring board, or a dry film made of the alkali-developable photosensitive resin composition of the present invention is applied to a printed wiring board. A film is formed by a method such as sticking to the surface, and then a negative film is applied onto the film thus obtained and irradiated with actinic rays to cure the exposed portion,
Further, the unexposed portion is eluted with a weak alkaline aqueous solution and developed.

Examples of the solvent suitable for dissolving the alkali-developable photosensitive resin composition of the present invention include ketones such as methyl ethyl ketone and methyl isobutyl ketone, and cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve and cellosolve acetate. To be

As a method of applying the solution in which the alkali-developable photosensitive resin composition of the present invention is dissolved to a printed wiring board, there are a solution dipping method, a spray method, a roller coater machine and a spinner coating machine. Yes, either method can be adopted. By these methods, for example, a film is formed on the printed wiring board by removing the solvent after applying it to a thickness of 20 to 30 μm.

Further, a dry film can be prepared by applying a solution in which the alkali-developable photosensitive resin composition of the present invention is dissolved onto a flexible support such as polyethylene terephthalate film and drying. In addition, in dry film,
A polyethylene film or the like may be coated for protection.

Light suitable for curing the alkali-developable photosensitive resin composition of the present invention includes light from a light source such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp or a metal halide lamp. The resin composition of the present invention can be cured not only by light but also by heat.

As a developer suitable for alkali development after exposure,
For example, an aqueous solution of an alkali metal carbonate or an alkaline earth metal carbonate, an aqueous solution of an alkali metal hydroxide, or the like can be given. In particular, a weakly alkaline aqueous solution containing 1 to 3% by weight of a carbonate such as sodium carbonate, potassium carbonate or lithium carbonate can be used to precisely develop a fine image. Alkaline development is 10 to 50 ℃, preferably 20 to 40 ℃
It can be carried out at a temperature of ° C using a commercially available developing machine or ultrasonic cleaning machine.

After alkali development, in order to improve the corrosion resistance of the exposed and hardened area, it is desirable to apply heat treatment to further harden it. When heat treatment is applied, water resistance to strong alkaline water, adhesion to metals such as copper, heat resistance and durability The surface hardness is significantly improved, and various properties required for a protective mask for a printed wiring board, such as electroless gold plating resistance and solder heat resistance, are further improved. The heat treatment condition is preferably 80 to 200 ° C. for 10 minutes to 2 hours.

The alkali-developable photosensitive resin composition of the present invention comprises
In addition to components (A), (B) and (C), photopolymerizable monomers and oligomers, curing accelerators having epoxy groups, thermal polymerization inhibitors, fillers, dyes, pigments, plasticizers, leveling agents, adhesion Additives such as improvers, defoamers, flame retardants, etc., and compounding agents and additives such as organic solvents can be compounded. The kind and the amount of such compounding agents and additives are the same as those of the present invention. It can be appropriately selected within a range that does not impair the properties of the developable photosensitive resin composition.

As the photopolymerizable monomer or oligomer, for example, 2
-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and other monomers having hydroxyl groups, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol di Acrylate, tetramethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, pentaerythritol diacrylate,
Acrylic esters such as pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipontaerythritol tetraacrylate, dipentaerythritol hexaacrylate, glycerol acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate , Trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, glycero Esters of unsaturated carboxylic acids such as esters of methacrylic acid such as methacrylate with aliphatic polyol compounds, urethane acrylate compounds obtained by reaction of diisocyanate with monohydric alcohol having at least one acrylate group or methacrylate group, etc. Can be mentioned. Further, these compounds may be used in combination of two or more kinds. These compounds act as a viscosity modifier or a photocrosslinking agent.

Examples of the epoxy group curing accelerator include amine compounds, imidazole compounds, carboxylic acids, phenols, quaternary ammonium salts, and methylol group-containing compounds. When the coating film obtained by using these in small amounts is post-heated, various properties such as heat resistance, solvent resistance, acid resistance, plating resistance, adhesion, electrical characteristics and hardness are improved. Therefore, particularly when used as a solder resist or an electroless gold plating resist, a suitable resist can be obtained.

Examples of the thermal polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine and the like.

Examples of the filler include white alumina, clay, talc, fine powder silica, barium sulfate, barium carbonate, magnesium oxide, titanium oxide and the like.

Examples of dyes and pigments include phthalocyanine green, phthalocyanine blue, phthalocyanine yellow, benzidine yellow, permanent red R, and brilliant carmine 6B.

Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, tricresyl and the like.

Examples of the defoaming agent and the leveling agent include silicon-based compounds, fluorine-based compounds, and acrylic compounds.

Examples of the flame retardant include inorganic flame retardants such as aluminum hydroxide and zinc borate, organic flame retardants such as tris- (β-chloroethyl) -phosphate, and halogen-containing phosphates such as pentachlorophenol methacrylate. An example is a flame retardant.

(Examples) Hereinafter, the present invention will be specifically described with reference to Examples. In addition, "part" indicates "part by weight".

Reference Examples 1-10 With the compounding composition (Reference Examples 1-10) mentioned later, the component (A) which is a photopolymerizable compound was synthesize | combined by the method described below.

(A) A compound having at least two epoxy groups and a solvent were put into a three-necked flask equipped with a stirrer, a reflux condenser and a thermometer, and heated to 50 to 60 ° C to form a uniform solution. . Next, (b) (meth) acrylic acid and (c) a monovalent saturated aliphatic carboxylic acid or a monovalent aromatic carboxylic acid,
P-Methoxyphenol (0.1% by weight of total solids) as a thermal polymerization inhibitor and 2-hydroxyethylimidazole (0.1% by weight of total solids) as a catalyst were added, and the temperature was raised to 80 to 90 ° C for 2 to 8%. Reacted for hours. At this time, a part of the reaction contents was taken out to an Erlenmeyer flask, the acid value was measured with 0.1N alcoholic potassium hydroxide solution using phenolphthalein as an indicator, and the point when the value became 1 or less was the end point of the reaction. And

Then (d) polybasic acid anhydride was added to this solution,
A photopolymerizable unsaturated compound (including Reference Examples 1 to 10 and an organic solvent) was obtained by reacting at ˜90 ° C. for 2 to 8 hours. At the end point of the reaction at this time, the acid value was determined by the same method as described above.

Blending composition Reference example 1 (a): Bisphenol A type epoxy resin (Epicoat
1001, Epoxy equivalent 450) 225 g Solvent: Ethyl cellosolve acetate 200 g (b): Acrylic acid 43 g (c): Propionic acid 22 g (0.30 mol) (d): Hexahydrophthalic anhydride Reference Example 2 (a): Bisphenol A Type Epoxy resin (Araldite 6071, Epoxy equivalent 450) 225g Solvent: Methyl cellosolve acetate 230g (b): Methacrylic acid 60g (0.70mol) (c): Isobutyric acid 18g (0.20mol) (d): Phthalic anhydride 133g (0.90) Reference Example 3 (a): Brominated bisphenol A type epoxy resin (Epicoat 1045, epoxy equivalent 500) 25 g Solvent: Ethyl cellosolve acetate 230 g (b): Acrylic acid 40 g (0.55 mol) (c): n-butyric acid 26 g (0.30 mol) (d): Tetrahydrophthalic anhydride 106 g (0.70 mol) Reference Example 4 (a): o-cresol novolac type epoxy resin (ESCN
-195HH, Epoxy equivalent 200) 200g Solvent: Ethyl cellosolve acetate 205g (b): Acrylic acid 43g (0.60mol) (c): Stearic acid 57g (0.20mol) (d): Succinic anhydride 80g (0.80mol) Reference example 5 (a): Brominated phenol novolac type epoxy resin (BREN-S, epoxy equivalent 280) 280 g Solvent: Ethyl cellosolve acetate 230 g (b): Acrylic acid 36 g (0.50 mol) (c): Propionic acid 30 g (0.40 mol) (D): 80 g (0.80 mol) of succinic anhydride Reference Example 6 (a): Bisphenol S type epoxy resin (Epicoat
807, Epoxy equivalent 500) 250 g Solvent: Methyl cellosolve acetate 275 g (b): Methacrylic acid 60 g (0.70 mol) (c): n-caproic acid 34 g (0.20 mol) (d): Maleic anhydride 69 g (0.70 mol) Reference Example 7 (a): Glycidyl methacrylate / styrene copolymer (epoxy equivalent 250) 250 g Solvent: Butyl cellosolve acetate 250 g (b): Methacrylic acid 52 g (0.60 mol) (c): n-butyric acid 26 g (0.30 mol) (d) : 133 g (0.90 mol) of phthalic anhydride Reference Example 8 (a): Bisphenol A type epoxy resin (Epicoat
1001, Epoxy equivalent 450) 225 g Solvent: Ethyl cellosolve acetate 220 g (b): Acrylic acid 65 g (0.90 mol) (c): Not used (d): Hexahydrophthalic anhydride 123 g (0.80 mol) Reference Example 9 (a ): Bisphenol A type epoxy resin (Epicoat
1001, Epoxy equivalent 450) 225 g Solvent: Ethyl cellosolve acetate 230 g (b): Acrylic acid 14 g (0.20 mol) (c): Propionic acid 52 g (0.70 mol) (d): Hexahydrophthalic anhydride 139 g (0.90 mol) Reference Example 10 (a): o-cresol novolac type epoxy resin (ESCN
-195HH, Epoxy equivalent 200) 200g Solvent: Ethyl cellosolve acetate 180g (b): Acrylic acid 58g (0.80mol) (c): Not used (d): Succinic anhydride 80g (0.80mol) Examples 1-7, comparison Examples 1-3 Components (A) and (B) obtained in Reference Examples 1-10,
The component (C), the photopolymerizable monomer, the inorganic filler pigment and the organic solvent were mixed in the proportions (parts by weight) shown in Table 1 and kneaded using a test three-roll mill to prepare a resist ink. Then, these resist inks were applied to a degreased and washed 1.6 mm thick copper clad laminate to a thickness of 17 to 25 μm, dried, and then a negative film was adhered to them, and 3
KW ultra high pressure mercury lamp [NMW-6, manufactured by Oak Manufacturing Co., Ltd.]
-N] with an illuminance of 5 mw / cm ² for ultraviolet light near the wavelength of 365 nm
It was exposed to light for 100 seconds. After the exposure, using a developing device (YCE-85 manufactured by Yoshitani Shokai Co., Ltd.), it was immersed in a 1 wt% sodium carbonate aqueous solution at 30 ° C. for 80 seconds to remove the unexposed portion of the coating film.
Developed. After that, heat treatment was performed at 145 ° C for 50 minutes using a hot air dryer.

Regarding the sample obtained in the above process, the drying property of the coating film, the exposure sensitivity, the developability with respect to the alkaline solution, the coating film hardness, the adhesion to the substrate, the solder heat resistance, the electroless gold plating resistance of the coating film, the chemical resistance, The insulation resistance was evaluated. The results are shown in Table 2.

Among these performance evaluations, regarding the drying property of the coating film, the developing property with respect to the alkaline aqueous solution, and the exposure sensitivity, the resist ink was applied on the copper clad laminate in a thickness of 17 to 25 μm,
The coating film obtained by drying at 70 ° C. for 30 minutes using a hot air drier was evaluated.

For hardness, adhesion to substrate, solder heat resistance, electroless gold plating resistance, chemical resistance, solvent resistance and insulation resistance, 500 mJ / cm ² after exposure and development, edge resistance was 5
After exposing and developing at 00mJ / cm ² , heat at 145 ℃ for 50 minutes,
The coating film as a solder resist after complete curing was evaluated.

 Each evaluation was carried out as follows.

(1) Drying property of coating film The drying property of the coating film was evaluated according to JIS K-5400.

 The evaluation ranks are as follows.

◯: No tack observed △: Slight tack observed ×: Remarkable tack (2) Exposure sensitivity Kodak stepper tablet No.2 (Eastman Kodak Co., optical density 0.15, 21 steps negative film)
Was adhered to the coating film and 500mJ / cm using a 3KW ultra high pressure mercury lamp.
^Two light doses were applied. Next, this coating film was subjected to a developability test with respect to a weak alkaline aqueous solution, which will be described later, to check the number of steps of the stepper blts remaining on the copper foil. In this evaluation method, the higher the sensitivity, the greater the number of remaining stages.

(3) Developability with Alkaline Aqueous Solution Using a 1% by weight sodium carbonate aqueous solution, development was carried out by a developing machine under a pressure of 2.1 kg / cm ² at 30 ° C. for 80 seconds. After development, the image was magnified 30 times and observed, and the remaining resin was visually evaluated.

 The evaluation ranks are as follows.

◯: Good developability (no resist left on the copper surface) X: Poor developability (some resist left on the copper surface) (4) Coating hardness JIS K-5400 According to the test method, a pencil hardness tester was used and the film was not scratched when a load of 1 kg was applied. As the pencil, "Mitsubishi High Uni" (manufactured by Mitsubishi Pencil Co., Ltd.) was used.

(5) Adhesion with the substrate Put a cross-cut on the coating film so that at least 100 eyes are made, and then perform a peeling test using an adhesive tape to visually evaluate the state of peeling of the eyes. did. The evaluation ranks are as follows.

◯: No peeling was observed at all measuring points Δ: Peeling was observed at 1 to 20 points among 100 measuring points ×: Peeling was observed at 21 or more points among 100 measuring points Items (6) Solder heat resistance According to JIS D-0202, the sample was immersed in a solder bath at 260 ° C for 20 seconds, and the state of the coating film after immersion was evaluated. The evaluation ranks are as follows.

◯: The appearance of the coating film is normal. ×: The appearance of the coating film is swollen, melted, and peeled. (7) Electroless gold plating resistance The patterned substrate obtained by the above method is degreased and washed, and then catalyst activation treatment. Then, it was treated with a commercially available electroless nickel plating solution (PH = 6) at 90 ° C for 15 minutes. Further, the electroless gold plating solution [PH = 6, KAu (CN) 3 g / l] was used for 90 minutes at 90 ° C. to deposit gold having a thickness of 2 μm. Next, a peeling test was performed using an adhesive tape, and the state of peeling on the copper circuit was visually evaluated. The evaluation ranks are as follows.

○: No peeling was found on the copper circuit △: Peeling was found at 1 to 2 places ×: Peeling was found at 3 or more places (8) Chemical resistance The following chemicals Each was dipped for 1 hour at 25 ° C and the appearance and adhesion after dipping were evaluated.

 Acid resistance 10 wt% HCl aqueous solution Alkali resistance 10 wt% NaOH aqueous solution Solvent resistance Trichloroethane Methylene chloride Isopropyl alcohol The rank of evaluation is as follows.

○: No abnormality ×: Melting or swelling (9) Insulation resistance A circular electrode was formed on the film according to JIS Z-3197, and the insulation after normal conditions and 55 ° C, 95% RH, 100 hours was measured by Toa Denpa Co., Ltd. It was measured by using a Super Megohmeter Model SM-5h manufactured by Mitsui Chemicals.

As is clear from Tables 1 and 2, it can be seen that the film made of the alkali-developable photosensitive resin composition of the present invention is excellent in electroless gold plating resistance and other properties.

(Effect of the Invention) Since the present invention is configured as described above, when a film made of the alkali-developable photosensitive resin composition of the present invention is formed on a printed wiring board, alkali development becomes possible after exposure. In addition, the exposed and hardened part forms an excellent solder resist and electroless gold plating resist, and further a solder mask. Therefore, according to the alkali-developable photosensitive resin composition of the present invention, electroless gold plating can be performed after the solder mask is formed, and waste in electroless gold plating can be eliminated.

In addition, the alkali-developable photosensitive resin composition of the present invention has acid resistance, alkali resistance, solvent resistance, solder heat resistance,
Since it also has excellent electrical insulation properties, mechanical strength, surface hardness, etc., it can be suitably used as a permanent protection mask for plating resists in the full additive method. In addition, it is used for etching resists and interlayer insulating materials related to printed wiring boards, photosensitive adhesives, paints, plastic reliefs, plastic hard coating agents, PS plates as offset printing plates, photosensitive liquids for screen printing and resist inks. It can be used in a wide range of fields.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-64-62375 (JP, A) JP-A-63-278052 (JP, A) JP-A-57-40517 (JP, A) JP-A-62- 104817 (JP, A) JP 2-43551 (JP, A) JP 2-173747 (JP, A) JP 2-173749 (JP, A) JP 2-190860 (JP, A)

Claims (3)

[Claims] 1. A composition comprising the following components (A), (B) and (C), wherein the proportion of the component (B) is 5 to 100 parts by weight relative to 100 parts by weight of the component (A), and the component (C) is Of 0.1 to 30
An alkali-developable photosensitive resin composition, which is part by weight. Component (A): (a) A compound having at least two epoxy groups is reacted with (b) acrylic acid or methacrylic acid and (c) a monovalent saturated aliphatic carboxylic acid or a monovalent aromatic carboxylic acid. A photopolymerizable unsaturated compound obtained by reacting the reaction product thus obtained with (d) a polybasic acid anhydride. Component (B): a compound having at least one epoxy group. Component (C): Photopolymerization initiator or sensitizer. 2. The alkali-developable photosensitive resin composition according to claim 1, wherein the compound having at least two epoxy groups is a compound represented by the following general formula [1]. (In the formula, R ₁ and R ₂ are a hydrogen atom or a methyl group, Y is a hydrogen atom or a bromine atom, and n is the degree of polymerization.) 3. The alkali-developable photosensitive resin composition according to claim 1, wherein the compound having at least two epoxy groups is a compound represented by the following general formula [2]. (However, in the formula, R ₃ , R ₄ and R ₅ are hydrogen atoms and have 1 to 5 carbon atoms.
Is a group selected from the group consisting of an alkyl group and a halogen atom, and m is an integer of 2 or more and represents the degree of polymerization. )