KR20060081361A - Photocuring/thermosetting one-component solder resist composition and print wiring board using same - Google Patents

Abstract

Provides alkali developable photocurable and thermally curable one-component solder resist compositions having excellent storage stability, workability, heat resistance, adhesion, electroless gold plating resistance, electroless tin plating resistance, and electrical properties, and printed wiring boards using the same do.

(A) To the copolymer containing an unsaturated monobasic acid (a) and the compound (b) which has one unsaturated group in 1 or more types of molecule, the compound (c) which has an alicyclic epoxy group and an unsaturated group together in one molecule is added. (B) a diluent, (C) photoinitiator, (D) melamine or its organic acid salt, and (E) inorganic filler, It is characterized by the above-mentioned.

Solder Resist Composition, Photo Curable, Thermal Curable, Printed Wiring Boards

Description

Photo-curable, thermosetting one-component solder resist composition and printed wiring board using same {PHOTOCURING / THERMOSETTING ONE-COMPONENT SOLDER RESIST COMPOSITION AND PRINT WIRING BOARD USING SAME}

<Patent Document 1> Japanese Patent Application Laid-Open No. 1-54390 (Patent Claims)

<Patent Document 2> Japanese Patent Application Laid-Open No. 8-335768 (claims)

INDUSTRIAL APPLICABILITY The present invention is suitable for use as a permanent mask of a printed wiring board, is image-formed by developing with an aqueous alkali solution after exposure, and is heat-cured to provide heat resistance, adhesion, electroless gold plating resistance, electroless tin plating resistance, and solder resist excellent in electrical properties. The present invention relates to an alkali developable photocurable and thermosetting one-component solder resist composition capable of forming a film. The present invention also relates to a printed wiring board using the composition for forming a solder resist pattern.

Currently, liquid alkali developing solder resists are used as solder resists of most printed wiring boards in order to form images by post-exposure development, heat-harden, and form a coating film from the viewpoint of high precision and high density. As an alkali developing type soldering resist using such a thin aqueous alkali solution, for example, a photosensitive resin, a photopolymerization initiator, a diluent, and an epoxy compound in which an acid anhydride is added to the reaction product of a novolak-type epoxy compound and an unsaturated monobasic acid are used. A two-component liquid solder resist composition containing has been proposed (see Patent Document 1, for example).

However, most of the liquid alkali developing solder resists include a main component composed mainly of a photosensitive resin, a photopolymerization initiator, and the like, in which an acid anhydride is added to a reaction product of a novolak-type epoxy compound and an unsaturated monobasic acid. It is a two-component soldering resist containing the diluent or the hardening agent which has an epoxy compound as a main component, and should be used after mixing a main material and a hardening agent well. Moreover, the usable time after mixing is short within 24 hours, and also the operation problem arises, such as developing defect, since the carboxyl contained in the main photosensitive resin and the epoxy group of the epoxy compound in a hardening agent react slowly between a drying process and a developing process. have. In addition, in terms of characteristics, there is a problem that the electroless tin plating resistance, which is increasing in demand to cope with lead-freeization, is not sufficient.

In addition, in order to solve the problems of workability and storage stability, for example, a high molecular compound, a diluent, a photopolymerization initiator, melamine or a derivative thereof, or a 2,4,6-trimercapto having a photoreactive group with a carboxyl group in a molecule thereof. A one-component solder resist containing -S-triazine has also been proposed (see Patent Document 2, for example). However, although this one-component solder resist is excellent in workability, its heat resistance and electroless gold plating resistance are unstable compared to that of the two-component liquid solder resist, which has not been brought to practical use. Of course, it did not have electroless tin plating resistance.

Therefore, this invention is made | formed in order to solve the problem which the said prior art has, The main objective is heat resistance, adhesiveness, and radio | wireless which have sufficient storage stability and workability which are the characteristics as one part type, and can fully satisfy | fill as a soldering resist. Alkali-developable photocurable and thermally curable one-component solder resist compositions having coating film properties such as gold plating resistance, electrical properties, and electroless tin plating resistance that were not sufficient even in conventional two-component solder resists, and dry films using the same And a printed wiring board.

As a result of intensive studies to achieve the above object, a first aspect of the present invention includes (A) an unsaturated monobasic acid (a) and a compound (b) having one unsaturated group in at least one molecule thereof. Copolymer-based resin having a carboxyl group formed by adding a compound (c) having an alicyclic epoxy group and an unsaturated group together in one molecule, (B) a diluent, (C) a photoinitiator, (D) melamine or an organic acid salt thereof And (E) alkali developable photocurable and thermosetting one-component solder resist compositions comprising an inorganic filler. Moreover, as another provision form, there exists a photocurable and thermosetting dry film obtained by apply | coating and drying the said soldering resist composition to a carrier film. According to a second aspect, after applying and drying the one-component solder resist composition on a printed circuit board surface formed with a circuit, or after laminating the dry film, pattern exposure is performed by an active energy line, and the unexposed portion is exposed by an aqueous alkali solution. The printed wiring board which develops and heat-hardens, and forms a soldering resist film is provided.

Best Mode for Carrying Out the Invention

The basic aspect of the alkali developable photocurable and thermosetting one-component solder resist composition of this invention contains (A) unsaturated monobasic acid (a) and the compound (b) which has one unsaturated group in 1 or more types of 1 molecule. A copolymer-based resin having a carboxyl group formed by adding a compound (c) having an alicyclic epoxy group and an unsaturated group together in one molecule, (B) diluent, (C) photopolymerization initiator, (D) melamine or organic The solder resist composition containing an acid salt and an inorganic filler (E) has storage stability and workability, and can be satisfied as a solder resist, heat resistance, adhesion, electroless gold plating resistance, electroless tin plating resistance, electrical properties, and the like. It discovered that it has the various characteristics of, and came to complete this invention.

That is, since the 1st characteristic expresses the characteristic as a soldering resist, without using a thermosetting composition, the alkali developable photocurable and thermosetting one-component soldering resist composition of this invention is excellent in film formability. A copolymer-based resin having a carboxyl group formed by adding a compound having an alicyclic epoxy group and an unsaturated group together in one molecule, a melamine or an organic acid salt thereof to a copolymer containing a basic acid and a compound having one unsaturated group in at least one molecule thereof. It is in combination. Melamine or its organic acid salt is used as its curing accelerator catalyst in a two-component solder resist composition incorporating a thermosetting component such as an epoxy resin, but it is considered to be ineffective in a composition that does not use a thermosetting component such as an epoxy resin. It became.

In the present invention, it was found that the heat resistance, the electroless gold plating resistance, and the electroless tin plating resistance were remarkably improved only when the specific copolymer-based resin (A) and melamine or organic acid salts thereof were used in combination. This cannot obtain these characteristics in combination with copolymer type resin comprised from another molecular skeleton like those described in the cited example mentioned above. This is because the active hydrogen of melamine or its organic acid salt is added to the molecular chain by partially adding Michael to the unsaturated double bond of this specific copolymer type resin (A) during heat-hardening, heat resistance improves, and the chelate effect to copper foil It is thought that the adhesiveness of a coating film and copper foil is improved by the rust prevention effect.

In addition, the electroless tin plating solution is a strongly acidic liquid, and in order to obtain resistance thereto, in addition to excellent adhesion between the resist and the copper foil, excellent surface curability is required, but this copolymer-based high molecular compound is an acrylate of a cresol or phenol novolac type epoxy resin. Unlike the photosensitive resin which has the unsaturated group and carboxyl group which added dibasic acid anhydride to a cargo together, since it has a conjugated double bond in a principal chain, it can have the outstanding photocurability.

Moreover, in order to achieve monoliquidity, the 2nd characteristic is to use an unsaturated group mainly as a reactive group of a coating film formation component, without using a thermally reactive epoxy resin or a melamine resin. In the unsaturated group, the reaction by light irradiation proceeds easily in the presence of a photopolymerization initiator, but the reaction by heat is unlikely to occur, so such a composition exhibits excellent storage stability, and one-component solution, which is one of the objects of the present invention, is achieved. .

The 3rd characteristic is that the shrinkage of hardening shrinkage is reduced by using an inorganic filler as an essential component and using a comparatively large quantity.

Hereinafter, each component of the one-component solder resist composition of this invention is demonstrated in detail.

First, to a copolymer comprising (A) an unsaturated monobasic acid (a) used in the present invention and a compound (b) having one unsaturated group in at least one molecule, an alicyclic epoxy group and an unsaturated group are combined in one molecule. Copolymer-type resin which has a carboxyl group which adds the compound (c) which has is acid value 30-150 mg KOH / g, More preferably, acid value 50-140 mg KOH / g. When the acid value is less than 30 mg KOH / g, the solubility in aqueous alkali solution becomes worse and development becomes difficult. On the other hand, when an acid value exceeds 150 mg KOH / g, since it develops to the coating film surface of an exposure part irrespective of exposure conditions, it is unpreferable.

Moreover, the weight average molecular weight of this copolymer resin is 8,000-70,000, More preferably, it is 10,000-50,000. In the present invention, the film formability due to the molecular weight effect of the resin is important, and if it is less than 8,000, sufficient film formability is not obtained, while if it is 70,000 or more, developability is not obtained.

Typical examples of the unsaturated monobasic acid (a) used in the production of this copolymer resin include acrylic acid, methacrylic acid, itaconic acid, β-carboxyl ethyl (meth) acrylate, and 2-hydroxyethyl (meth). The compound which added dibasic acid anhydride to hydroxyl-containing (meth) acrylates, such as an acrylate, 2-hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate, etc., As a dibasic acid anhydride, Phthalic anhydride, methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, maleic anhydride, itaconic anhydride, nadine anhydride and the like. Among them, acrylic acid or methacrylic acid is particularly preferable in view of photosensitivity and storage stability. These unsaturated monobasic acids (a) can be used individually or in mixture of 2 or more types.

In addition, in this specification, a (meth) acrylate generically refers to an acrylate and a methacrylate, and the same also about another similar expression.

Moreover, as a compound (b) which has one unsaturated group in 1 molecule, Vinyl compounds, such as styrene and vinyl acetate; Alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, lauryl (meth) acrylate, isopropyl (meth) acrylate and t-butyl (meth) acrylate; 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, hydroxyethyl (meth) acrylate, (Meth) acrylic acid esters, such as hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and phenylglycidyl ether (meth) acrylate, etc. are mentioned.

Examples of the compound (c) having one alicyclic epoxy group and one unsaturated group in one molecule include 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, and 3 And 4-epoxycyclohexyl butyl (meth) acrylate, 3,4-epoxycyclohexylmethylamino acrylate, and the like. Among them, 3,4-epoxycyclohexylmethyl (meth) acrylate is particularly preferable.

The diluent (B) used in the present invention is used to improve the workability by adjusting the viscosity of the ink composition, to increase the crosslinking density, to improve the adhesiveness, and the like, and to use a reactive diluent such as a photopolymerizable monomer (B- 1) and a well-known conventional organic solvent (B-2) can be used.

As a reactive diluent (B-1), Alkyl (meth) acrylates, such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; Hydroxyalkyl (meth) acrylates, such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; Alkylene jade, such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol Mono or di (meth) acrylates of seed derivatives; Polyhydric alcohols such as hexanediol, nonanediol, tricyclodecanedimethanol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, trishydroxyethyl isocyanurate or ethylene oxide or propylene thereof Polyvalent (meth) acrylates of oxide adducts; (Meth) acrylates of ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth) acrylate and polyethoxydi (meth) acrylate of bisphenol A; (Meth) acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether and triglycidyl isocyanurate; And melamine (meth) acrylate etc. are mentioned.

These can be used individually or in combination of 2 or more types, From the point of adhesiveness, (meth) acrylate containing hydrophilic group is preferable, and the polyfunctional (meth) acrylate is preferable at the point of photocurability. It is preferable that the compounding quantity of these photopolymerization monomers is 20-120 mass parts with respect to 100 mass parts of copolymerization resin (A), More preferably, it is 20-100 mass parts. If it is less than 20 mass parts, photoreactivity is bad, and when it is more than 120 mass parts, since touch-drying property worsens, it is unpreferable.

As said organic solvent (B-2), Ketones, such as methyl ethyl ketone and cyclohexanone; Aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; Cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether Glycol ethers such as these; Esters such as ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; Aliphatic hydrocarbons such as octane and decane; Known conventional organic solvents such as petroleum solvents such as petroleum ether, petroleum naphtha and solvent naphtha can be used. These organic solvents can be used individually or in combination of 2 or more types.

The blending amount of such an organic solvent varies depending on the coating method or the boiling point of the organic solvent to be used, and is not particularly limited. However, when a high boiling point organic solvent is contained in a large amount, the touch drying property is reduced or flows to dry after coating. It is not preferable because it generates sex.

As a photoinitiator (C) used by this invention, For example, benzoin and benzoin alkyl ether, such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether; Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, etc. Acetophenones; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone- Aminoacetophenones such as 1; Anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone and 1-chloroanthraquinone; Thioxanthones, such as 2, 4- dimethyl thioxanthone, 2, 4- diethyl thioxanthone, 2-chloro thioxanthone, and 2, 4- diisopropyl thioxanthone; Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal: benzophenones such as benzophenone; or xanthones; (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphineoxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine jade Phosphine oxides such as seeds and ethyl-2,4,6-trimethylbenzoylphenylphosphinate; Various peroxides, titanocene-type initiator, etc. are mentioned, These are N, N- dimethyl amino benzoate ethyl ester, N, N- dimethyl amino benzoic acid isoamyl ester, pentyl-4- dimethyl amino benzoate, and triethylamine And photosensitizers such as tertiary amines such as triethanolamine and the like. These photoinitiators can be used individually or in combination of 2 or more types. Moreover, the compounding quantity of these photoinitiators (C) is 1-25 mass parts with respect to 100 mass parts of copolymerization resin (A), More preferably, it is 2-20 mass parts. When the said compounding quantity is less than 1 mass part, since photocurability falls and the pattern formation after exposure and image development becomes difficult, it is unpreferable. On the other hand, when it exceeds 25 mass parts, since thick film sclerosis | hardenability falls and it becomes a cause of high cost, it is unpreferable.

As melamine or its organic acid salt (D), what reacted melamine or the organic acid of melamine and sugar mole can be used. The organic acid salt of melamine is obtained by dissolving melamine in boiling water and filtering the precipitated salt by adding an organic acid dissolved in water or a hydrophilic solvent such as alcohol. Since one amino group in the melamine molecule has a high reactivity, but the other two are low in reactivity, the reaction proceeds stoichiometrically to form a melamine salt in which one organic acid is added to one amino group in the melamine molecule. As an organic acid, a carboxyl group-containing compound, an acidic phosphate ester compound, a sulfonic acid-containing compound can be considered, and all can be used, but a carboxyl group-containing compound is more preferable.

Examples of the carboxyl group-containing compound include formic acid, acetic acid, propionic acid, butyric acid, lactic acid, glycolic acid, acrylic acid, methacrylic acid and the like, and dicarboxylic acids include oxalic acid, malonic acid, succinic acid and glutaric acid. , Adipic acid, sebacic acid, maleic acid, itaconic acid, phthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, tetrahydro Phthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, crotonic acid, and tricarboxylic acid include trimellitic acid. Among these, salt obtained by equimolar reaction of dicarboxylic acid and melamine is especially preferable because there is little characteristic fall of the soldering resist which adds this. Moreover, polybasic acid anhydride can also be used. Generally, polybasic acid anhydrides are easily ring-opened by, for example, dissolving in boiling water to produce the corresponding polycarboxylic acids.

It is preferable that the compounding quantity of these melamine or its organic acid salt (D) is 1-25 mass parts, More preferably, it is 2-20 mass parts with respect to 100 mass parts of copolymer resins (A). When the said compounding quantity is less than 1 mass part, adhesiveness and heat resistance fall, and when it exceeds 25 mass parts, photoreactivity will fall. In addition, when using the organic acid salt of melamine, it is usually required about 1.5 to 2 times that of using melamine.

As the inorganic filler (E), known conventional inorganic fillers such as barium sulfate, barium titanate, silicon oxide powder, finely divided silicon oxide, amorphous silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, mica and the like It can be used individually or in combination of 2 or more types. These are used for the purpose of suppressing the cure shrinkage of a coating film and improving characteristics, such as adhesiveness and hardness. It is preferable that the compounding quantity is 50-250 mass parts with respect to 100 mass parts of copolymerization resin (A). When less than the said range, adhesiveness, heat resistance fall etc. generate | occur | produce, On the other hand, since a fall of a coating film intensity | strength, a sensitivity fall, etc. generate | occur | produce, it is not all preferable.

Moreover, if necessary, a well-known conventional coloring pigment, a coloring dye, a thermal polymerization inhibitor, a thickener, an antifoamer, a leveling agent, a coupling agent, a flame retardant adjuvant, etc. can be used.

Moreover, in this invention, you may use well-known conventional epoxy resins, such as a phenol novolak-type epoxy resin, a cresol novolak-type epoxy resin, a bisphenol-type epoxy resin, a biphenyl type epoxy resin, and triglycidyl isocyanurate, as needed. However, it is one-liquid and care must be taken not to impair the storage stability.

In addition, the one-component solder resist composition of the present invention may be provided in the form of a liquid, paste or dry film. When supplying as a dry film, after apply | coating the soldering resist composition of this invention by a roll coater, a doctor bar, a wire bar system, a spin coating system, a doctor plate system, etc., on a carrier film, for example, at 60-100 degreeC, It can obtain by drying in a set drying furnace, removing an organic solvent, and bonding a mold release film as needed. At this time, the film thickness of the resist on the carrier film is adjusted to 5 to 150 mu m, preferably 10 to 60 mu m. As the carrier film, films such as polyethylene terephthalate and polypropylene are preferably used.

The one-component solder resist composition of the present invention having the composition as described above is diluted as necessary and adjusted to a viscosity suitable for the coating method, which is, for example, a screen printing method, a curtain coating method, a spray coating method, or the like on a printed circuit board having a circuit formed thereon. A coating-free coating film can be formed by apply | coating by methods, such as a roll coating method, and volatilizing the organic solvent contained in a composition at the temperature of 70-90 degreeC, for example. Thereafter, the photomask is selectively exposed with an active energy ray, and the unexposed portion can be developed with a dilute aqueous alkali solution to form a resist pattern, and further heat cured to provide heat resistance, adhesion, electroless gold plating resistance, and electrolessness. The printed circuit board which has the soldering resist film excellent in sea-plating resistance, electrical property, etc. is formed.

As said diluted aqueous alkali solution, aqueous alkali solution, such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, can be used. As the irradiation light source for exposure, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a xenon lamp, a metal halogen lamp, or the like can be used. In addition, a laser beam etc. can also be used as an active ray.

<Example>

Although an Example and a comparative example are shown to the following and this invention is demonstrated concretely, of course, this invention is not limited to the following Example. In addition, in the following, "part" means a "mass part" unless there is particular notice.

Synthesis Example 1

In a flask equipped with a thermometer, a stirrer, a dropping lot and a reflux condenser, 300.0 g of dipropylene glycol monomethyl ether as a solvent was heated to 100 ° C, 172.0 g of methacrylic acid and ε-caprolactone modified methacrylic acid (average molecular weight 344 ), A mixture of 172.0 g, methyl methyl methacrylate 150.0 g, 142.0 g dipropylene glycol monomethyl ether, and 10.0 g of azobisisobutyronitrile was added dropwise over 3 hours as a polymerization catalyst, and further stirred at 110 ° C. for 3 hours. The polymerization catalyst was deactivated to obtain a copolymer resin solution. After cooling this resin solution, 170.0 g of 3, 4- epoxycyclohexyl methyl acrylate (Dycel Chemical Industries, Ltd. cycloma-A400), 3.0 g of triphenylphosphines, and 1.3 g of hydroquinone monomethyl ether are added. The ring-opening addition reaction of epoxy was performed by heating up and stirring at 100 degreeC. The copolymer-based resin having two or more acryloyl groups and carboxyl groups in one molecule thus obtained had a weight average molecular weight of 25,000, a nonvolatile content of 60% by weight, and an acid value of solids of 90 mg KOH / g. Hereinafter, this reaction solution was called varnish A-1.

Synthesis Example 2

Into a flask equipped with a thermometer, a stirrer, a dropping lot, and a reflux condenser, 276.0 g of dipropylene glycol monomethyl ether as a solvent and 8.0 g of azobisisobutyronitrile were added as a polymerization catalyst. It heated at 80 degreeC by nitrogen atmosphere, the monomer which mixed 172.0 g of methacrylic acid, 100.0 g of methyl methacrylate, and 114.0 g of ethyl methacrylate was dripped over about 3 hours, and after stirring for 1 hour, the temperature was 115 It heated up to ° C and deactivated the polymerization catalyst to obtain a copolymer resin solution.

After lowering this resin solution to 85-95 degreeC, 0.3 g of methylhydroquinones as a polymerization inhibitor and 2.0 g of triphenylphosphines are added as a catalyst, 160.0 g of glycidyl methacrylates were dripped gradually, and it was made to react for about 24 hours. . The copolymer-based resin having two or more (meth) acryloyl groups and carboxyl groups in one molecule thus obtained had a weight average molecular weight of 16,000, a nonvolatile content of 60% by weight, and an acid value of a solid of 90 mg KOH / g. Hereinafter, this reaction solution was called varnish A-2.

Synthesis Example 3

In a flask equipped with a thermometer, a stirrer, a dropping lot, and a reflux condenser, 280.0 g of diethylene glycol monoethyl ether acetate as a solvent and 2.8 g of azobisisobutyronitrile were added as a polymerization catalyst. It heated at 60 degreeC under nitrogen atmosphere, the monomer which mixed 100.0 g of methyl methacrylates and 142.0 g of glycidyl methacrylate was dripped over about 4 hours, and after stirring for 2 hours, the temperature was raised to 115 degreeC, The polymerization catalyst was deactivated to obtain a copolymer resin solution.

After cooling this resin solution, 0.2 g of methylhydroquinone as a polymerization inhibitor and 2.0 g of triphenylphosphines were added as a catalyst, and it heated to 95-105 degreeC. 72.0 g of acrylic acid was slowly added dropwise to this mixed solution and allowed to react for 24 hours until the acid value became 4.0 mg KOH / g or less. Further, 106.0 g of tetrahydrophthalic anhydride was added and reacted for 8 hours until absorption of the acid anhydride disappeared by infrared absorption analysis. The copolymer resin having two or more acryloyl groups and carboxyl groups in one molecule thus obtained had a weight average molecular weight of 24,000, a nonvolatile content of 60% by weight, and an acid value of solids of 92 mg KOH / g. Hereinafter, this reaction solution was called varnish A-3.

Examples 1 to 7, and Comparative Examples 1 to 4

Using each varnish obtained in Synthesis Examples 1 to 3, each component was blended at the blending ratio shown in Table 1 below, kneaded using three roll mills, and alkali-developed photocurable and thermosetting one-component solder resist compositions. Was prepared. In addition, at the time of printing, it diluted with the organic solvent as needed.

Example Comparative example One 2 3 4 5 6 7 One 2 3 4 Varnish A-1 166 166 166 166 166 166 166 166 Varnish A-2 166 166 Varnish A-3 166 Irg-369 ^{* 1} 5 5 5 5 5 5 5 5 5 5 Irg-907 ^{* 2} 10 TMPTA ^{* 3} 50 50 50 50 50 50 50 50 50 DPHA ^{* 4} 50 50 Melamine 3 8 5 5 5 5 5 Melamine Phthalate 8 15 Phthalocyanine green One One One One One One One One One One One Silicone Defoamer One One One One One One One One One One One talc 20 20 20 20 20 20 20 20 20 20 20 Barium sulfate 100 100 100 100 100 100 100 100 100 100 100 DPM ^{* 5} 50 50 50 50 50 50 50 50 50 50 50 Epicoat 828 ^{* 6} 40 Remarks * 1: Photoinitiator of Ciba Specialty Chemicals * 2: Photoinitiator of Ciba Specialty Chemicals * 3: Trimethylolpropane triacrylate * 4: Dipentaerythritol hexaacrylate * 5: Dipropylene glycol monomethyl ether * 6 : Bisphenol A epoxy resin of Japan epoxyxylene

About the one-part type | mold soldering resist composition of the said Examples 1-7 and Comparative Examples 1-4, each item below was tested and evaluated. The evaluation results are shown in Table 2 below. In addition, the method of an evaluation test is shown below.

(1) One-liquid viscosity stability: The composition of each said Example and the comparative example was stored in the thermostat of 20 degreeC, 5 rotation values of the EHD type viscometer were measured until 6 months, and the presence or absence of thickening was confirmed. Judgment criteria were as follows.

(Circle): A thickening rate is 120% or less.

(Triangle | delta): A thickening rate is 120 to 200% or less.

X: Gelation or thickening rate is 200% or more.

(2) developability

The one-component solder resist compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 4 were respectively coated on a copper-clad substrate by screen printing, dried at 90 ° C. for 60 minutes in a hot air circulation drying furnace, and spray pressure. for 1 minute development with a 1 wt% Na ₂ CO ₃ solution of 0.2 MPa, to evaluate the developability of the coating film surface with the following criteria.

(Circle): A coating film is removed completely and there is no residue.

△: very little filler remaining,

×: There is residue of coating film

(3) sensitivity

The one-component solder resist compositions obtained in the above Examples 1 to 7 and Comparative Examples 1 to 4 were completely coated by screen printing on the printed wiring boards formed with circuits, respectively, and dried at 80 ° C. for 30 minutes in a hot air circulation drying furnace. These substrates exposed to Kodak step tablet No.2 touched 200 mJ / cm ^2, and a, and 1 minutes developed with a 1 wt% Na ₂ CO ₃ aqueous solution and the spraying pressure of 0.2 MPa, a coating film was evaluated in a number of stages that fully remains.

(4) solder heat resistance

The one-component solder resist compositions obtained in the above Examples 1 to 7 and Comparative Examples 1 to 4 were completely coated by screen printing on the printed wiring boards formed with circuits, respectively, and dried at 80 ° C. for 30 minutes in a hot air circulation drying furnace. It touched the negative film is a solder resist pattern drawn on these substrates exposed in the exposure conditions of the exposure dose 300 mJ / cm ^2, and for 1 minute development with a 1 wt% Na ₂ CO ₃ aqueous solution and the spraying pressure 2 MPa to form a solder resist pattern. This board | substrate was thermosetted at 150 degreeC for 60 minutes, and the evaluation board | substrate was produced.

The rosin-based flux was applied to the evaluation substrate, immersed in a solder bath previously set at 260 ° C. for 30 seconds to wash the flux with isopropyl alcohol, and then a tape peeling test was performed to evaluate expansion, peeling and discoloration of the resist layer. It was.

(Circle): A change is not confirmed at all.

(Triangle | delta): A thing with the change of discoloration etc. very slightly

X: expansion of a resist layer and peeling

(5) electroless gold plating resistance

An evaluation substrate was produced in the same manner as in the above (4). Using this commercially available electroless nickel plating solution and an electroless gold plating solution, the evaluation substrate was subjected to electroless gold plating under conditions of 5 µm of nickel and 0.03 µm of gold. About the evaluation board | substrate after this plating, the tape peeling test was done and the peeling of the resist layer and plating penetration were evaluated.

(Circle): A change is not confirmed at all.

(Triangle | delta): Very slight peeling and a thing with permeation

X: thing with peeling in a coating film

(6) Electroless Tin Plating Resistance

An evaluation substrate was produced in the same manner as in the above (4). The evaluation substrate was subjected to pretreatment (acidic degreasing + soft etching + sulfuric acid treatment), and electroless tin plating was carried out using a commercially available electroless tin plating solution under conditions of a plating thickness of 1 μm (70 ° C., 12 minutes). The peeling test with the cellophane adhesive tape was performed about the evaluation board | substrate after this plating, and the peeling of a resist layer was evaluated.

(Circle): A change is not confirmed at all.

(Triangle | delta): Very slight peeling and a thing with permeation

X: thing with peeling in the whole resist layer

(7) electrical insulation

Using the comb-shaped electrode B coupon of the IPC B-25 test pattern, an evaluation substrate was prepared under the same conditions as in (4) above, and a bias voltage of DC 100V was applied to the comb-shaped electrode, and the temperature was 85 ° C and 85% RH. The insulation resistance value after 1000 hours was measured in the thermo-hygrostat.

Example Comparative example One 2 3 4 5 6 7 One 2 3 4 One liquid viscosity stability ○ ○ ○ ○ ○ ○ × ○ ○ ○ ○ Developability ○ ○ ○ ○ ○ ○ × ○ ○ ○ ○ Sensitivity 8 steps 7-speed 8 steps 7-speed 6 steps 7-speed 6 steps 8 steps 7-speed 7-speed 6 steps Solder heat resistance ○ ○ ○ ○ ○ ○ ○ △ △ △ △ Electroless Gold Plating Resistance ○ ○ ○ ○ ○ ○ ○ × △ × × Electroless Tin Plating Resistance ○ ○ ○ ○ ○ ○ ○ × × × × Electrical insulation (Ω) > 10 ¹² > 10 ¹² > 10 ¹² > 10 ¹² > 10 ¹² > 10 ¹² > 10 ¹² > 10 ¹² > 10 ¹² > 10 ¹² > 10 ¹²

As is clear from the results shown in Table 2, the one-component solder resist compositions of Examples 1 to 7 according to the present invention are excellent in one-liquid stability, have a high dry control width and sensitivity, and the obtained cured coating films also have solder heat resistance and electrolessness. It was found that the plating plating resistance, the electroless tin plating resistance, and the electrical characteristics were excellent. On the other hand, in the one-component solder resist compositions of Comparative Examples 2 to 4 using the copolymer resins obtained in Synthesis Examples 2 and 3, the solder heat resistance, the electroless gold plating resistance, and the electroless tin plating resistance were not good. In addition, even if the copolymer resin obtained in Synthesis Example 1 is used, the one-component solder resist composition of Comparative Example 1, in which no melamine or melamine organic acid salt is added, has all solder heat resistance, electroless gold plating resistance, and electroless tin plating resistance. It was not good.

The alkali developable photocurable and thermally curable one-component solder resist composition of the present invention has developability as a one-liquid, long developability, and develops heat resistance, adhesiveness, and electrolessness that can be sufficiently satisfied as a solder resist. Since it has coating film characteristics, such as gold plating resistance and electrical characteristics, it becomes possible to provide the printed wiring board which was excellent in productivity and highly reliable at low cost. Moreover, since it has electroless tin plating tolerance, it can respond to the request | response to lead-free conversion. Moreover, since the copolymer resin (A) used by this invention can remove a halogen completely, it can respond to the requirement of halogen freeization.

Claims (8)

(A) To the copolymer containing an unsaturated monobasic acid (a) and a compound (b) having one unsaturated group in at least one molecule, a compound (c) having an alicyclic epoxy group and an unsaturated group together in one molecule is added, Alkali-developable photocurable and thermally curable comprising copolymerizable resin having a carboxyl group, (B) diluent, (C) photoinitiator, (D) melamine or organic acid salt thereof, and (E) inorganic filler. One-component solder resist composition. The one-component solder resist composition according to claim 1, wherein the copolymer-based resin (A) has a weight average molecular weight of 10,000 to 50,000. The one-component soldering resist composition according to claim 1 or 2, wherein the compound (c) having an alicyclic epoxy group and an unsaturated group together in one molecule is 3,4-epoxycyclohexylmethyl (meth) acrylate. The said diluent (B) contains a reactive diluent (B-1) and an organic solvent (B-2), The compounding quantity of a reactive diluent (B-1) 100 mass of the said copolymer-type resin (A) of Claim 1 A one-component solder resist composition having 20 parts by mass to 120 parts by mass with respect to parts. The compounding quantity of a photoinitiator (C) is 1-25 mass parts, and the compounding quantity of melamine or its organic acid salt (D) is 1-25 mass parts with respect to 100 mass parts of said copolymerization resins (A). The compounding quantity of an inorganic filler (E) is 50-250 mass parts, The one-component soldering resist composition characterized by the above-mentioned. The photocurable and thermosetting dry film obtained using the one-component soldering resist composition of any one of Claims 1-5. The printed wiring board formed by forming the soldering resist film by the one-component soldering resist composition of any one of Claims 1-5 on the printed wiring board surface with a circuit. The printed wiring board formed by forming the soldering resist film by the dry film of Claim 6 on the printed wiring board surface in which the circuit was formed.