JP3072811B2 - Liquid resist ink composition and printed circuit board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid resist ink composition suitable for manufacturing a printed wiring board and developable with a dilute alkaline aqueous solution, and a printed circuit board using the same.

[0002]

2. Description of the Related Art Conventionally, a screen printing method has been widely used as a resist pattern forming method for various printed wiring boards for consumer and industrial use. However, in recent years, as the wiring density of printed wiring boards has increased and strict dimensional accuracy has been required for pattern formation, the resolution is low, ink bleeds during printing, and ink is buried between lines. The screen printing method, in which defects are likely to occur, cannot cope with recent high density. In order to solve such a problem, a dry film or a liquid developable resist ink has been developed. Among them, a resist ink which can be developed with a dilute alkaline aqueous solution has attracted attention.

[0003] Such a liquid resist ink composition is disclosed in JP-B-56-40329 and JP-B-57-457.
No. 85 discloses a composition containing a reaction product obtained by reacting an unsaturated monocarboxylic acid with an epoxy resin and adding a polybasic acid anhydride as an essential component (hereinafter referred to as “acid anhydride addition type”). Epoxy acrylate "). Also,
JP-A-61-243869 discloses a weak alkali developing type containing a thermosetting component comprising an acid anhydride addition type epoxy acrylate derived from a novolak type epoxy resin, a photopolymerization initiator, a diluent and an epoxy compound. A photosensitive resin composition for a liquid resist ink is disclosed.

However, the acid anhydride-added epoxy acrylate used in the above liquid resist ink composition has aromaticity and is easily colored by heating, so that it has insufficient heat resistance and light resistance. At present, a material having a sufficiently high molecular weight has not been obtained.

[0005]

The object of the present invention is to provide good resolution and solvent resistance, excellent electrical properties such as plating resistance and electric corrosion resistance, flexibility and substrate adhesion. In particular, it is an object of the present invention to provide a photosensitive resin composition for a liquid resist ink capable of developing a dilute alkali and having a very good heat resistance and capable of forming a good pattern even when exposed to a low amount of light, and a printed circuit board using the same. is there.

[0006]

According to the present invention, there is provided a liquid resist ink composition which can be developed with a dilute aqueous alkaline solution. The following general formula (I)

[0007]

Embedded image

Wherein R is an organic compound residue having k active hydrogens, and n ₁ , n ₂ ·· _nk are 0 or 1 to 5
It is an integer of 0, and the sum is 1 to 50. Also, the following functional groups in the formula

[0009]

Embedded image

[0010]

(However, R ′ represents a hydrogen atom, an alkyl group, an alkylcarbonyl group or an arylcarbonyl group.)
May be replaced by Isocyanate group in the molecule of the reaction product of the compound represented by
UV-curable resin obtained by reacting a compound having at least two and a saturated or unsaturated polybasic acid anhydride,

B. A photopolymerization initiator, C.I. Diluent and D. It is characterized by containing a thermosetting epoxy compound.

Hereinafter, the present invention will be described in detail. <A. Regarding UV-curable resin> As described above, the UV-curable resin is obtained by reacting the compound represented by the general formula (I) with an unsaturated monocarboxylic acid ,
Isocyanate groups such as sophorone diisocyanate
An isocyanate compound having at least two
Obtained by reacting a saturated or unsaturated polybasic acid anhydride.
You.

The alicyclic epoxy compound represented by the general formula (I) used in the present invention can be synthesized by a known method. For example, in the general formula (I), k = 3
Are triols such as glycerin and trimethylolpropane, and compounds where k = 1 are ring-opening polymerization of 4-vinylcyclohexene-1-oxide using methanol, ethanol, propanol and butanol as initiators. It is obtained by doing.

In the preparation of the liquid resist ink composition according to the present invention, when a compound of the general formula (I) where k ≧ 2 is used, particularly high film strength is obtained, and k =
When the compound of No. 1 is used, the adhesion to the printed circuit board is particularly improved.

As the unsaturated monocarboxylic acid, for example,
Acrylic acid, methacrylic acid, crotonic acid, cinnamic acid and the like can be mentioned, but acrylic acid is particularly preferred.

Examples of the isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate, and toluidine. Examples include diisocyanate, lysine diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, triphenylmethane triisocyanate, and polymethylene polyphenyl polyisocyanate. Isocyanate, tolylene diisocyanate and xylylene diisocyanate And the like, and among them, an aromatic ring such as isophorone diisocyanate and hydrogenated xylylene diisocyanate is preferred because there is little problem of coloring at a high temperature.
Those that do not have are optimal.

Further, as the saturated or unsaturated polybasic anhydride, for example, maleic anhydride, succinic anhydride,
Dibasic anhydrides such as itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride and methylhexahydrophthalic anhydride; and trimellitic anhydride, anhydride Examples thereof include acid anhydrides of three or more basic acids such as pyromellitic acid, benzophenonetetracarboxylic anhydride and methylcyclohexenetetracarboxylic anhydride.

The method for producing the ultraviolet curable resin will be described in detail. For example, the compound represented by the general formula (I) is dissolved in an organic solvent such as carbitol acetate, cellosolve acetate and methyl ethyl ketone, and hydroquinone and hydroquinone monomethyl ether are dissolved. And tertiary amines such as benzyldimethylamine and triethylamine, and quaternary ammonium salts such as trimethylbenzylammonium chloride and methyltriethylammonium chloride, or a catalyst such as triphenylstibine. The unsaturated monocarboxylic acid such as acrylic acid is used in an amount of preferably about 0.7 to 1.3 chemical equivalents, more preferably about 0.9 to 1.1 chemical equivalents with respect to one chemical equivalent of the epoxy group. In a conventional manner, preferably from 60 to 50 ° C., particularly preferably 80 to
The reaction is performed at a reaction temperature of 120 ° C. to obtain a first reaction product composed of epoxy acrylate.

Subsequently , an isophore is added to the first reaction product.
The ratio of isocyanate compound such as long diisocyanate is preferably 0.01 to 0.90 chemical equivalent, more preferably 0.05 to 0.40 chemical equivalent, with respect to 1 chemical equivalent of the former secondary hydroxyl group. In a conventional manner, a catalyst prepared in the previous reaction with or without the addition of an organic tin compound such as dibutyltin dilaurate or a tertiary amine such as benzyldimethylamine as a catalyst at a reaction temperature of 20 to 100 ° C. The reaction is performed by heating and stirring to obtain a second reaction product. If the reaction amount of the isocyanate group with respect to 1 chemical equivalent of the hydroxyl group in the first reaction product is more than 0.90 chemical equivalent, the solubility of the ultraviolet curable resin in the diluent tends to be poor, and particularly, 0.05 The best use characteristics are obtained in the range of ０．４0.40 chemical equivalent.

Further , an acid anhydride is added to the second reaction product, and a ratio of 0.99 to 0.10 chemical equivalent of the acid anhydride to 1 chemical equivalent of the hydroxyl group in the first reaction product. To react. At this time, as the acid anhydride, at least one selected from the above-mentioned saturated or unsaturated polybasic acid anhydrides is selected, and reacted by a conventional method, preferably by heating and stirring at 70 to 120 ° C. to obtain an ultraviolet curable resin.

The UV-curable resin can be made into a non-tacky solid at room temperature by partially cross-linking with an isocyanate compound as described above. Exposure becomes easy, and the molecular weight of the ultraviolet curable resin is increased, so that it is possible to obtain a resist ink composition capable of forming a good pattern even in exposure with a small amount of light.

The UV-curable resin is not limited to the above-mentioned synthesis examples, but can be synthesized by various conventional synthesis methods. For example, the compound represented by the general formula (I) may be synthesized with an acrylic acid or the like. After the reaction with a saturated monocarboxylic acid to form an epoxy acrylate, first, an acid anhydride may be reacted, and then, an isocyanate compound or the like may be reacted for synthesis.

The acid value of the obtained ultraviolet curable resin is 30.
It is preferably about 160 mgKOH / g. If the acid value is less than 30, the solubility in an alkali developing solution will be poor, and if it is greater than 160, it will be a factor of deteriorating properties such as chemical resistance of the cured resist film.

The UV-curable resin is prepared from a known epoxy acrylate to which a polybasic acid anhydride is added and an epoxy compound other than a hydrogenated epoxy compound in the same manner as the UV-curable resin according to the present invention. The induced ultraviolet curable resin can be used in combination as appropriate.

<B. Regarding photopolymerization initiator> Examples of photopolymerization initiators include benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether and their alkyl ethers, and acetophenone and 2,2-dimethoxy-2-phenylacetophenone. , 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one And anthraquinones such as 2-methylanthraquinone and 2-amylanthraquinone; and 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and the like. And 2,
Thioxanthones such as 4-diisopropylthioxanthone, ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal, benzophenones or xanthones such as benzophenone, and lucilin TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide manufactured by BASF) And the like, and these may be used in combination with a known photopolymerization accelerator such as benzoic acid or a tertiary amine. These photopolymerization initiators are preferably 0.1 to 30 parts by weight, particularly preferably 1 to 25 parts by weight, based on 100 parts by weight of the ultraviolet curable resin.
It is blended by weight.

<C. Regarding Diluent> As the diluent, a photopolymerizable monomer and / or an organic solvent can be used. Examples of the photopolymerizable monomer include 2-hydroxyethyl acrylate and 2-hydroxyethyl acrylate.
Hydroxypropyl acrylate, N-vinylpyrrolidone, acryloylmorpholine, methoxytetraethylene glycol acrylate, methoxypolyethylene glycol acrylate, polyethylene glycol diacrylate, N, N-dimethylacrylamide, N-methylolacrylamide, N, N-dimethylaminopropylacrylamide, N , N-dimethylaminoethyl acrylate, N, N-dimethylaminopropyl acrylate and melamine acrylate, or water-soluble monomers such as methacrylates corresponding to the acrylates, diethylene glycol diacrylate, triethylene glycol diacrylate, propylene glycol diacrylate, Tripropylene glycol diacrylate, phenoxyethyl ac Rate tetrahydrofurfuryl acrylate, cyclohexyl acrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, isobonyl acrylate, cyclopentanyl (Mono or di) acrylate, cyclopentenyl (mono or di) acrylate, or methacrylates corresponding to the acrylate and mono-, di-, tri- or more of polybasic acid and hydroxyalkyl (meth) acrylate Water-insoluble monomers such as polyester, polyester acrylate, urethane acrylate, bisphenol A Epoxy acrylates such as epoxy acrylate, phenol novolak type epoxy acrylate and cresol novolak type epoxy acrylate (even if these epoxy acrylates are partially cross-linked with a compound having at least two isocyanate groups in the molecule or a polybasic acid anhydride) Good), high molecular weight acrylate monomers such as polyester acrylate and urethane acrylate. The water-soluble monomer, the water-insoluble monomer, the polymer acrylate monomer and the like can be used alone or in combination with one another as appropriate.

Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone;
And aromatic hydrocarbons such as toluene and xylene; and cellosolves such as cellosolve and butyl cellosolve; and carbitols such as carbitol and butyl carbitol; and ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate and butyl carbitol. Acetates such as acetate and propylene glycol monomethyl ether acetate can be exemplified.

The photopolymerizable monomer such as the water-soluble monomer, the water-insoluble monomer and the high-molecular-weight acrylate monomer dilutes the ultraviolet-curable resin to make it easy to apply and adjusts the acid value to improve the photopolymerizability. give. When a water-soluble monomer is used alone or in combination with a water-insoluble monomer or a high-molecular-weight acrylate monomer, the solubility in an alkaline aqueous solution is improved when the mixing ratio of the water-soluble monomer is increased. Since the water resistance of the completely cured resist film is reduced, the resist film may be blended to such an extent that the resist film does not become sparingly soluble in an aqueous alkali solution, preferably in a range of 100% by weight or less based on the ultraviolet curable resin. In addition, the organic solvent dissolves and dilutes the ultraviolet curable resin, makes it applicable as a liquid, and forms a film by drying.

The above diluent is preferably used alone or as a mixture of two or more kinds in a range of 10 to 95% by weight based on the total amount of the liquid resist ink composition, though it depends on a coating method.

<D. About thermosetting epoxy compound> As the thermosetting epoxy compound, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, N- Glycidyl type epoxy resin or alicyclic epoxy resin, triglycidyl isocyanurate, “Y
X-4000 "(epoxy resin manufactured by Yuka Shell Epoxy) and the like having two or more epoxy groups in one molecule. These are preferably used in an amount of 10 to 150 parts by weight, particularly preferably 30 to 100 parts by weight, based on 100 parts by weight of the ultraviolet curable resin.

The liquid resist ink composition comprising the above components A to D may contain, if necessary, an imidazole derivative, a polyamine, a guanamine, a tertiary amine,
Epoxy resin curing agents and curing accelerators such as quaternary ammonium salts, polyphenols and polybasic anhydrides, and fillers such as barium sulfate, silicon oxide, talc, clay and calcium carbonate, and phthalocyanine blue, phthalocyanine green, Coloring pigments such as titanium oxide and carbon black, and various additives such as antifoaming agents, adhesion promoters or leveling agents, dispersion stabilizers, or hydroquinone, hydroquinone monomethyl ether, pyrogallol, tertiary butyl catechol, and phenothiazine May be added.

The liquid resist ink composition according to the present invention is prepared by kneading the respective components and additives with, for example, a three-roll mill, a ball mill, a sand mill or the like. Further, as a method of using the same, for example, after applying the composition by spraying, a roll coater or screen printing on a printed wiring board, performing pre-curing at 70 to 90 ° C. to volatilize the solvent, and then drawing a pattern Contact the mask with the dry ink surface with or without contact, using a chemical lamp, low-pressure mercury lamp,
A pattern can be formed by irradiating and developing an ultraviolet ray using a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like, and a target resist film can be formed by post-heating. In addition, this composition can be used not only as a solder resist but also as an etching resist by not applying post-curing by heat.

[0034]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Synthesis Examples, Reference Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples. Note that “parts” and “%” used below are all based on weight.

[Synthesis Example 1] The following general formula (II)

[0036]

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(Where n ₁ , n ₂ and n ₃ are 1 to 1)
It is an integer of 0, and the sum is 10-20. 185 parts of EHPE-3150 (Epoxy resin manufactured by Daicel Chemical Co., Ltd., epoxy equivalent: 185) represented by the following formula (1) was heated and dissolved in 60 parts of carbitol acetate, and 74 parts of acrylic acid, 0.1 part of hydroquinone and benzyl were stirred under stirring. Dimethylamine (1.4 parts) was added, and the mixture was reacted at 90 to 100 ° C for 24 hours by a conventional method. After cooling the reaction mixture ,
60 parts of tall acetate, swazol 1500 (Maruzenishi
Oil based aromatic solvent) 63 parts, 2,4-tolylenedi
5 parts of isocyanate and 0.1 part of dibutyltin dilaurate.
One part was added and reacted at 50 ° C. for 4 hours with stirring. Further
Then, 76 parts of tetrahydrophthalic anhydride was added to the reaction product, and the mixture was heated to 100 ° C. and reacted with stirring for about 3 hours to obtain an ultraviolet-curable resin (A-1).

[Synthesis Example 2] EHPE-3150 (Epoxy resin manufactured by Daicel Chemical Co., Ltd.)
Instead of the epoxy equivalent 185), the following general formula (II)
I)

[0039]

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The use (wherein, n is an integer from 10 to 20.) In EHPE-1150 represented a (manufactured by Daicel Chemical Industries epoxy resin, epoxy equivalent 172) 172 parts
The amount of SWASOL 1500 was changed to 56 parts.
By following the same procedure as in Synthesis Example 1 except for the above, an ultraviolet curable resin (A-2) was obtained.

[Synthesis Example 3] Instead of 5 parts of 2,4-tolylene diisocyanate,
Swolazole 15 using 7 parts of sophorone diisocyanate
Synthesis Example 1 except that the blending amount of 00 was changed to 64 parts.
By operating in the same manner as described above, the ultraviolet curable resin (A-
3) was obtained.

[Synthesis Example 4] Epicron N-680 (a product of Dainippon Ink and Chemicals, Inc. )
Zole novolak epoxy resin, epoxy equivalent 214)
214 parts were heated and dissolved in 60 parts of carbitol acetate.
Acrylic acid 74 parts, hydroquinone
0.1 parts and 0.7 parts of benzyldimethylamine were added,
It was 24 hours reaction at 90 to 100 ° C. in a conventional manner. this
Swazol 1500 (aromatic manufactured by Maruzen Petrochemical Co., Ltd.)
94 parts), stirred and cooled, and then epoxy
Rate (B-1) was obtained.

REFERENCE EXAMPLE 1 A mixture of 212 parts of Epicron N-673 (cresol novolak resin manufactured by Dainippon Ink and Chemicals, epoxy equivalent 212) dissolved in 60 parts of carbitol acetate under heating was stirred with 74 parts of acrylic acid. , Hydroquinone 0.1
And 0.7 parts of benzyldimethylamine,
The reaction was carried out at 100 ° C. for 24 hours by a conventional method. After cooling the reaction solution, 65 parts of carbitol acetate and 70 of swazole 1500 (an aromatic solvent manufactured by Maruzen Petrochemical Co.) were used.
Parts and 76 parts of tetrahydrophthalic anhydride.
C. and the reaction was carried out under stirring for about 3 hours to obtain an ultraviolet curable resin (C-1).

REFERENCE EXAMPLE 2 A solution prepared by heating and dissolving 178 parts of Epicoat 154 (Novolak epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 178) in 63 parts of carbitol acetate was mixed with 74 parts of acrylic acid and hydroquinone 0 under stirring. .1 part and 0.7 part of benzyldimethylamine were added and reacted at 90-100 ° C. for 24 hours by a conventional method. After cooling the reaction solution, 25 parts of carbitol acetate, 15 parts of swazole
Then, 88 parts of 00 (aromatic solvent manufactured by Maruzen Petrochemical Co., Ltd.) and 76 parts of tetrahydrophthalic anhydride were added, and the mixture was heated to 100 ° C. and reacted under stirring for about 3 hours to produce an ultraviolet curable resin (C-2). Obtained.

[Examples 1 to 3 and Comparative Examples 1 and 2] The components shown in Table 1 below were kneaded with a three-stage roll in each composition, and the diluted alkali developing type liquid resist ink composition according to each of the Examples and Comparative Examples was used. Was prepared.

[0046]

[Table 1]

[Test Results] A copper-clad laminate made of a glass epoxy base material of 35 μm of copper foil and a pattern obtained by etching the copper-clad laminate in advance using the dilute alkali-developing liquid resist ink compositions of the above Examples and Comparative Examples Was applied on the entire surface of the printed wiring board on which screen was formed by screen printing, and precure was performed at 90 ° C. for 20 minutes to volatilize the solvent to obtain a dry coating film having a thickness of 20 μm. Then, a mask on which the pattern is drawn is directly applied to the coating film surface, irradiated with 300 mJ of ultraviolet light, and then developed with a 1% aqueous solution of sodium carbonate as a developing solution to form a pattern, and further heated at 150 ° C. for 30 minutes. Hardening was performed to prepare a test piece. Table 2 shows the results of various physical property tests on the obtained test pieces.

[0048]

[Table 2]

The method for evaluating the test results is as follows. A --- Excellent. ○ ---- Excellent. Δ −−− Slightly inferior. X --- Inferior.

[0050]

As described above, the liquid resist ink composition according to the present invention has good resolution and solvent resistance, electrical properties such as plating resistance and electrolytic corrosion resistance, flexibility and substrate. Not only is it possible to form a good pattern even with excellent heat resistance, particularly excellent heat resistance and a low exposure dose , especially because it uses an ultraviolet curable resin partially cross-linked with an isocyanate compound, Excellent resist properties can be obtained after precure, and contact exposure of a pattern can be easily performed, and a resist ink composition capable of forming a good pattern even with low-light exposure can be obtained.

Accordingly, this liquid resist ink composition can be suitably used as a solder resist ink or an etching resist ink, particularly for the production of printed wiring boards for consumer or industrial use.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-120308 (JP, A) JP-A-6-93221 (JP, A) JP-A 5-179185 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C09D 11/00-11/20 C08G 59/17 C08G 59/40 H05K 3/00-3/28

Claims (4)

(57) [Claims] 1. A. First Embodiment The following general formula (I): [Wherein, R is an organic compound residue having k active hydrogens, n ₁ , n ₂ ·· _nk is 0 or an integer of 1 to 50,
The sum is 1 to 50. Further, the following functional group in the formula: (However, R ′ represents a hydrogen atom, an alkyl group, an alkylcarbonyl group or an arylcarbonyl group). The compound represented by the formula (I) and an unsaturated monocarboxylic acid have at least two isocyanate groups in the molecule.
An ultraviolet-curable resin obtained by reacting a compound having two or more and a saturated or unsaturated polybasic acid anhydride; A photopolymerization initiator, C.I. Diluent and D. A liquid resist ink composition containing a thermosetting epoxy compound and developable with a dilute alkaline aqueous solution. 2. Component C is a high molecular weight acrylate monomer.
2. An epoxy acrylate as a binder.
The liquid resist ink composition according to the above. 3. The method according to claim 1 , wherein the epoxy acrylate is an isocyanate.
Compounds or polybases having at least two thio groups in the molecule
3. The liquid resist ink composition according to claim 2, partially crosslinked with an acid anhydride . 4. A liquid resist according to claim 1, 2 or 3.
A printed circuit board manufactured using the ink composition .