JPH05186729A - Solder resin ink composition curable with combination of ultraviolet ray and heat - Google Patents

Abstract

PURPOSE:To provide the title composition which is prepared without using any organic solvent, can form a resist film curable with a combination of ultraviolet rays and heat, gives a coating film excellent in strength after ultraviolet curing, and forms, when thermally cured, a resist film excellent in adhesion, resistance to soldering heat, resistance to electroless gold plating, resistance to electrolytic corrosion, and hardness. CONSTITUTION:The title composition consists mainly of a compound (A) having at least two acrylate or methacrylate groups in the molecule, a monofunctional acrylate or methacrylate compound (B), a photopolymerization initiator (C), an epoxy resin (D) having at least one epoxy group in the molecule, and a curing agent (E) for epoxy resin, wherein the weight ratio of the total of components A and B to the component D is (50:50) to (95:5) and the component B accounts for at least 10wt.% of the total solids.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a UV / heat curable solder resist ink composition having excellent heat resistance, gold plating resistance and electric insulation used for printed wiring boards.

[0002]

2. Description of the Related Art In the recent field of printed wiring boards, the demand for liquid photosolder resists has increased along with the increase in density, but the screen printing method has been applied from the viewpoint of productivity and cost. ing. Conventionally, a thermosetting solder resist ink composition has been used for those with severe reliability requirements, and an ultraviolet curable solder resist ink composition has been used for those for which productivity is important. .. By the way, the thermosetting type has a problem that the curing time is long and the productivity is inferior, the heat has an adverse effect on the substrate, in particular, the dimensional accuracy is inferior and warpage occurs. Further, since it contains an organic solvent as an essential component, it has a bad influence on the problem of working environment, generation of voids and bleeds, and electrolytic corrosion. On the other hand, the ultraviolet-curing type does not have the above problems, but is inferior in reliability. Further, it is well known that the characteristics are improved by post-heat treating the ultraviolet curable solder resist ink, but various characteristics have not reached the level of the curable solder resist ink. From these viewpoints, development of a solder resist ink having both productivity and reliability is desired.

By the way, the technique of curing by using both ultraviolet rays and heat is widely used in various fields such as paints, adhesives and molded products, and also in printed wiring boards, it is used as a chip adhesive, potting agent and the like. It is used. For example, Japanese Patent Application Laid-Open No. 53-142447 discloses a method of curing an epoxy resin with cations generated by ultraviolet rays and further heat curing, and Japanese Patent Application Laid-Open No. 60-20837.
No. 7 and No. 61-272228 disclose a method of using a partially vinyl esterified epoxy resin, and JP-A No. 63-238174 discloses that an epoxy resin and an ultraviolet radical curable resin can be combined. It is disclosed.

[0004]

However, when the techniques disclosed in the above-mentioned JP-A-53-142447, JP-A-60-208377 and JP-A-61-272228 are used for a solder resist, curability, Adhesion,
There are fundamental problems such as cost, and the characteristics required for solder resist have not been satisfied. Further, the one disclosed in Japanese Patent Laid-Open No. 63-23817 has a problem that the coating film strength after ultraviolet curing is weak and scratches are likely to occur during work. Moreover, since a compound having two or more polymerizable double bonds in one molecule is used as the unsaturated compound, if a large amount of the unsaturated compound is used, the thermosetting property becomes poor and the final coating There was a problem that the resistance of the membrane was poor. Further, unless the working viscosity of the resist ink is lowered, the workability for printing is markedly restricted, and therefore an organic solvent is required. Therefore, not only the touch dryness at the time of UV curing is lowered, but also voids are formed. There is also a problem that the occurrence and the electrolytic corrosion property are significantly deteriorated.

Therefore, an object of the present invention is to solve the above-mentioned problems in the prior art. That is, an object of the present invention is to form a resist film that is cured by ultraviolet rays and heat without using an organic solvent, and has excellent coating strength after the effect of ultraviolet rays, and is formed after heat curing. The resist film has excellent adhesion, solder heat resistance,
UV rays with electroless gold plating resistance, electrolytic corrosion resistance and hardness
It is intended to provide a heat-curable solder resist ink composition.

[0006]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of the above problems, and as a result, have used a monofunctional acrylate or methacrylate compound as an essential component as an ultraviolet curing component, By setting the ratio of the ultraviolet curing component and the thermosetting component to 50% or more of the ultraviolet curing component, the coating film strength after ultraviolet curing is increased, the post-thermosetting property is not deteriorated, and the productivity is good, Moreover, they have found that the characteristics equal to or higher than those of the thermosetting solder resist ink can be obtained, and have completed the present invention.

That is, the curable solder resist ink composition of the present invention is of a combined UV / heat type,
-1) A compound having at least two acrylate or methacrylate groups in one molecule, (A-2) a monofunctional acrylate or methacrylate compound, (B) a photopolymerization initiator, and (C) at least one in one molecule. Mainly composed of an epoxy resin having an epoxy group and (D) an epoxy curing agent, and the weight ratio of component (A-1) + component (A-2): component (C) is in the range of 50:50 to 95: 5. Yes,
Moreover, the component (A-2) is characterized by being 10% by weight or more of the total solid content.

The UV / heat combined curable solder resist ink composition of the present invention is described in detail below. In the present invention, the ultraviolet curable component is composed of the component (A-1) and the component (A-2), and the compounding amount thereof is a weight ratio with respect to the epoxy resin of the component (C) which is a thermosetting component. In 5
It is necessary to be in the range of 0:50 to 95: 5, preferably 60:40 to 80:20. When the ratio of the UV-curing component is lower than 50:50, the strength of the coating film after the UV effect becomes weaker, and 95:
When the value is higher than 5, problems occur in reliability, corrosion resistance, galvanic corrosion resistance and the like.

In the present invention, examples of the compound having at least two acrylate or methacrylate groups in one molecule of the component (A-1) used as one of the ultraviolet curing components are as follows. Poly (meth) acrylates of polyhydric alcohols (both acrylate and methacrylate are abbreviated as “(meth) acrylate” hereinafter), for example, ethylene glycol di (meth).
Acrylate, propylene glycol glycol di (meth) acrylate, 1,4-butanediol di (meth)
Acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol diacrylate (for example, HDDA manufactured by Nippon Kayaku Co., Ltd.), 1,6-hexanediol dimethacrylate, diethylene glycol di (meth) acrylate, di Propylene glycol glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane triacrylate (Toagosei Kagaku Kogyo Co., Ltd .: Aronic M-309, Nippon Kayaku Co., Ltd. ): Kayahard TMPT
A), trimethylolpropane trimethacrylate, glycerin tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta- or hexa (meth) acrylate, trismethacryloyloxyethyl isocyanurate, trisacryloyloxyisocyanurate (TOA) Synthetic Chemical Industry Co., Ltd .: Aronic M-215) and the like.
Further, as the acrylate oligomer, acrylic acid or methacrylic acid immiscible substance of epoxy resin, for example, diacrylate of bisphenol A type epoxy resin (TOHRAD-3700 manufactured by Toto Kasei Co., Ltd.), diacrylate of phenol novolac type epoxy resin (Toto). Kasei Co., Ltd .: TOHRAD-63223 and Showa Highpolymer Co., Ltd .: SP-4010), bisphenol F type epoxy resin diacrylate (Showa Highpolymer Co., Ltd .: SP)
-1506), a terminal isocyanate group-containing compound obtained by previously reacting a diisocyanate compound and a polyol with two or more (meth) acryloyloxy groups in the molecule obtained by reacting an alcoholic hydroxyl group-containing (meth) acrylate. Urethane acrylate oligomer having (for example, Toagosei Kagaku Kogyo Co., Ltd .: Aronic M
-1100, M-1200), an oligoester acrylate in which a (meth) acryloyl group is introduced into the terminal of a polyester resin synthesized from a divalent or trivalent alcohol and a dibasic acid (for example, manufactured by Toa Gosei Chemical Industry Co., Ltd.). Examples include Aronic M-6100, Aronic M-6300, Aronic M-8030, and Aronic M-8060).

As the monofunctional acrylate or methacrylate compound of the component (A-2) which is another one of the ultraviolet curing components, alkyl (meth) acrylate, 2
-Methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, benzyl ( Examples thereof include (meth) acrylate, cyclohexyl (meth) acrylate, and glycidyl methacrylate. In the present invention,
The monofunctional acrylate or methacrylate compound of the component (A-2) may be a compound having a hydroxyl group. Specific examples of such a compound include 2-hydroxy-3-phenoxypropyl (meth) acrylate and 2-hydroxy-3-phenoxypropyl (meth) acrylate.
Examples thereof include hydroxyethyl acrylate, 2-hydroxyethyl methacrylate (light ester HO: manufactured by Kyoeisha Oil & Fat Co., Ltd.), and 2-hydroxypropyl (meth) acrylate.

In the present invention, the component (A-2) is required to be at least 10% by weight of the total solid content, preferably 10 to 20% by weight. (A
If the blending amount of -2) is lower than 10% by weight, the adhesion after UV curing becomes a problem.

As the photopolymerization initiator of the component (B), known ones are used. For example, ketals such as benzyl methyl ketal (Irguacure 651 manufactured by Ciba-Geigy), benzoin methyl ether, benzoin ethyl ether, benzoin-1-propyl ether, benzoin, benzoins such as α-methylbenzoin,
Anthraquinones such as 9,10-anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone and 2-ethylanthraquinone, benzophenones such as benzophenone, p-chlorobenzophenone and p-dimethylaminobenzophenone, 2-hydroxy-2-methylpro Piophenone (Merck & Co .: Darocur117
3), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropiophenone (manufactured by Merck: Da
rocur1116) and other propiophenones, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 (Irugac manufactured by Ciba-Geigy).
ure907) etc. can be used. The component (B) is used in an amount of 0.1 to 20 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the ultraviolet curing component.

In the present invention, as the epoxy resin of component (C) which is a thermosetting component, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, alicyclic epoxy resin, phenol novolac type Epoxy resin, cresol novolac type epoxy resin, resorcinol diglycidyl ether, xylene resin modified novolac type epoxy resin, bisphenol S modified epoxy resin, bisphenol A modified novolac type epoxy resin, glycidyl amines and the like can be used.

Specific examples of these are Epicoat 828, Epicoat 834, Epicoat 1001, and Epicoat 1004 as bisphenol A type epoxy resins.
(Above, Yuka Shell Epoxy Co., Ltd.), DER-33
0, DER-331, DER-661, DER-664
(Above, Dow Chemical Co., Ltd.), Araldite GY-26
0, Araldite GY-280, Araldite 607
1, Araldite 6084 (above, manufactured by Ciba Geigy)
Etc. As the bisphenol F type epoxy resin, Epicoat 807 (Yukaka Shell Epoxy Co., Ltd.)
Manufactured by Dainippon Ink and Chemicals, Inc.). As the alicyclic epoxy resin, Araldite CY-175, Araldite CY-1
77, Araldite CY-179, Araldite CY-
184, Araldite CY-192 (above, manufactured by Ciba Geigy), ERL-4221, ERL-4209, ER
L-4299 (above, manufactured by Union Carbide), Epicoat 171 (manufactured by Yuka Shell Epoxy Co., Ltd.) and the like can be mentioned.

As the bisphenol AD type epoxy resin, Epomic R-710 (Mitsui Petrochemical Industry Co., Ltd.)
Manufactured) is a typical example. Also, as a phenol / novolak type epoxy resin, Epicoat 1
52, Epikote 154 (Okaka Shell Epoxy Co., Ltd.)
Made), Araldite EPN-1138, Araldite E
Examples include PN-1139 (all manufactured by Ciba-Geigy), Epicron N-738, and Epiclon N-770 (manufactured by Dainippon Ink and Chemicals, Inc.). As cresol / novolak type epoxy resin, EOCN-102S, EO
CN-103, EOCN-104 (all manufactured by Nippon Kayaku Co., Ltd.), Epiclon N-665, Epicron N-6
73 (manufactured by Dainippon Ink and Chemicals, Inc.).
As a xylene resin-modified novolac type epoxy resin,
Epicron EXA-1857 (manufactured by Dainippon Ink and Chemicals, Incorporated), and bisphenol A-modified novolac type epoxy resins include Epicron N-865 and Epiclon N-880 (manufactured by Dainippon Ink and Chemicals).
Examples of the bisphenol S-modified novolac type epoxy resin include Epiclon EXA-4004 (manufactured by Dainippon Ink and Chemicals, Inc.), and resorcinol-modified novolac type epoxy resin is Epiclon N.
-510 is given. Further, as glycidyl amines, Sumiepoxy ELN-125, Sumiepoxy EL
N-120, Sumiepoxy ELN-434 (above, Sumitomo Chemical Co., Ltd. product), TETRAD-X (Mitsubishi Gas Chemical Co., Inc. product), etc. are mentioned.

Further, as the epoxy resin curing agent as the component (D), imidazole compounds, dicyandiamide, biguanide compounds, organic acid anhydrides, polyhydric phenol compounds and the like are preferably used. Specifically, as the imidazole compound, Curezol 2MZ, Curezol 2E4MZ, Curezol 2PZ, Curezol C
11Z, Curezol 1B2MZ, Curezol 2MZ
-CN, Curezol 2E4MZ-CN, Curezol 2PZ-CN, Curezol MZ-AZINE, Curezol 2E4MZ-AZINE, Curezol C11Z
-AZINE, Curezol AMZ, Curezol 2P
HZ, Curezol 2P4MHZ, Curezol 2PH
Z-CN, Curezol 2E4MZ-BIS (above, manufactured by Shikoku Chemicals Co., Ltd.), carboxylic acid salt of the above imidazole compound, salt of the above imidazole compound and mono- or polyhydric phenol compound, isocyanurate of the above imidazole compound ( Shikoku Chemicals Co., Ltd .: Curesol 2
MZ-OK, Curezol 2PZ-OK, Curezol 2MA-OK), adducts of the above imidazole compounds with monoepoxy compounds or epoxy resins, and salts of these adducts with polyhydric phenol compounds.

As the biguanide compound, o-toluyl biguanide (manufactured by Ouchi Shinko Chemical Co., Ltd .: NOXCELLER B)
G), cyanoethylated o-toluyl biguanide, o
Examples include trilbiguanide monoepoxy adducts and epoxy resin adducts. Examples of organic acid anhydrides include Epicron B4400 (manufactured by Dainippon Ink and Chemicals, Inc.), 1,2,3,4-butanetetracarboxylic dianhydride, long-chain dibasic acid anhydride (Okamura Oil Co., Ltd.). Made: I
PU-22AH, SB-20AH) and the like. Examples of the polyhydric phenol compound include pyrogallol and novolac resin (for example, BRG-55 manufactured by Showa High Polymer Co., Ltd.).
8), cresol novolac resin and the like. Examples of the bisurea include aromatic dialkylureas, aromatic monoalkylureas, alicyclic dialkylureas, aliphatic dialkylureas, and the like, ultraviolet curable,
Considering storage stability and the like, an alicyclic dialkyl urea (for example, San-Apro Co .: U-CAT3503N) can be preferably used. Furthermore, Tris-
It is also possible to use a tertiary amine compound such as dimethylaminomethylphenol (K-54, manufactured by Anchor Chemical Co.), benzyldimethylamine and the like.

These components (D) are used in the range of 1 to 20 parts by weight with respect to 100 parts by weight of the component (C).
It is preferably used in the range of 1 to 10 parts by weight.

The ultraviolet / heat curable solder resist ink composition of the present invention comprises the components (A-1) and (A-
2), (B), (C), and (D), if necessary,
Inorganic filler, inorganic and organic pigments for coloring, thixotropic agent for imparting appropriate printability, leveling agent and defoaming agent for forming a smooth coating film,
A flame retardant for imparting self-extinguishing property can also be included.

[0020]

EXAMPLES The present invention will be described below with reference to examples and comparative examples. In addition, "part" means "part by weight" unless otherwise specified. Examples 1 to 6 and Comparative Examples 1 to 5 Components and amounts shown in Table 1 below (numerals indicate parts).
60 parts of precipitating barium sulfate as a filler, 5 parts of finely divided silica, and 1 part of a coloring pigment (phthalocyanine green) are added to each mixture, and the particle size according to JIS K-5400 is 12.5 μm by a three-roll mill. The mixture was sufficiently kneaded so as to obtain the resist ink composition.
The components in Table 1 are as follows.

Lipoxy SP-4010 (Polyacrylate of phenol novolac type epoxy resin manufactured by Showa High Polymer Co., Ltd.) Aronix M8060 (Acryloyl group-introduced oligoester acrylate manufactured by Toagosei Chemical Industry Co., Ltd.) TOHRAD-3700 (Toto) Kasei Co., Ltd. bisphenol A type epoxy resin diacrylate) Kayahard TMPTA (Nippon Kayaku Co., Ltd. totimethylol propane triacrylate) Light ester HO (Kyoeisha Yushi Co., Ltd. 2-hydroxyethyl methacrylate) Irga Cure 651 (benzyl methyl ketal manufactured by Ciba Geigy) Epicoat 807 (bisphenol F type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.) U-CAT3502T (aromatic dialkyl urea manufactured by San-Apro) -CAT3503N (manufactured by San-Apro Ltd. alicyclic dialkylurea) CUREZOL 2E4MZ (manufactured by Shikoku Chemicals Co., Ltd. imidazole compound)

[0022]

[Table 1]

The characteristics of the obtained resist ink composition were evaluated as follows. That is, a circuit pattern was formed on both sides of a glass fiber reinforced epoxy resin laminated plate with double-sided copper clad by an ordinary method, and acid treatment, buffing, washing with water and drying were performed. A resist ink is applied to one surface of this epoxy resin plate by a screen printing method so as to have a film thickness of 15 to 25 μm, and an air-cooled 80 W / cm 3 lamp type high pressure mercury lamp (OHM: HHM-8400 / E-FS). Type)
After irradiating ultraviolet rays at a conveyor speed of 6 m / min, the resist ink was applied to the other surface in the same manner and was irradiated with ultraviolet rays. 1 for the obtained epoxy resin plate
A heat curing treatment was performed at 50 ° C. for 20 minutes to prepare a test piece. In addition, in the case of Comparative Example 2, the UV irradiation after the application of the resist ink was not performed, the heat curing of one surface was performed at 140 ° C. for 15 minutes, and the heat curing of the other surface was performed at 140 ° C. for 20 minutes. Was produced.

With respect to the obtained test pieces, the characteristics of the coating film after ultraviolet curing and the coating film after curing using both ultraviolet rays and heat were evaluated. The results are shown in Table 2. The test conditions and evaluation criteria are as follows. 1) Touch-free drying It was measured according to JIS K-5400 5.8. Those that were dry to the touch were rated as ◯, and those that were not dry to the touch were rated as x. 2) Pencil hardness Measured according to JIS K-5400 6.14. 3) Adhesion According to JIS D-0202, when 100 crosses of 1 x 1 mm grid are engraved on the coating film and peeled off with cellophane tape, even if one grid is not peeled off, even one peels off. What was done was marked with x. The test was performed on both the copper foil and the coating film on the resin. 4) Solder heat resistance The test piece was immersed in molten solder at 260 ° C for 30 seconds, immediately cooled under running water, and then the state of the coating film was observed. When there were no abnormalities such as swelling, peeling and melting in the coating film, it was evaluated as ◯, and when some abnormality was observed, it was evaluated as x. 5) Resistance to Electroless Gold Plating Plating (3 μm nickel layer and 0.05 μm nickel layer) was performed by immersing in an electroless nickel plating solution at 80 ° C. for 30 minutes and then in an electroless gold plating solution at 95 ° C. for 30 minutes. Then, the state after the cellophane tape was attached and peeled off was observed. The case where no abnormality was observed was marked with ◯, and the case of peeling was marked with x. 6) Electrolytic property In the comb-shaped electrode pattern of JIS Z-3197, 60
The test piece was held under a direct current of 50 V in an atmosphere of ° C and a relative humidity of 95%. When there was no abnormality for 1000 hours or more, it was evaluated as ◯, when abnormality such as discoloration of the conductor was recognized within 100 hours, as ×, and when abnormality was recognized within 500 hours was evaluated as Δ.

[0025]

[Table 2]

[0026]

Since the resist ink of the present invention has the above-mentioned constitution, it is possible to form a resist film which is curable to both ultraviolet rays and heat without using an organic solvent. And, the strength of the coating film after ultraviolet curing of the formed resist film is excellent, and the post-thermosetting property is also excellent, such as adhesion, solder heat resistance, electroless gold plating resistance, electrolytic corrosion resistance, and electrical resistance. A resist film excellent in insulation and hardness can be formed.

Claims (2)

[Claims] 1. (A-1) A compound having at least two acrylate or methacrylate groups in one molecule,
(A-2) A monofunctional acrylate or methacrylate compound, (B) a photopolymerization initiator, (C) an epoxy resin having at least one epoxy group in one molecule, and (D) an epoxy curing agent as a main component. (A-
1) + component (A-2): component (C) in a weight ratio of 50: 5.
It is in the range of 0 to 95: 5, and the component (A-2) is
A curable solder resist ink composition for combined use of ultraviolet rays and heat, which comprises 10% by weight or more of the total solid content. 2. A compound having one or more hydroxyl groups is used as the monofunctional acrylate or methacrylate compound, and dicyandiamide or a derivative thereof and bisurea or a derivative thereof are used in combination as an epoxy curing agent. A curable solder resist ink composition as described in combination with ultraviolet and heat.