JPS6112772A - Epoxy resin ink composition - Google Patents

Abstract

PURPOSE:The titled composition, containing an epoxy resin, poly-p-phenol, 2- vinyl-4,6-diamino-s-triazine and an imidazole compound, and having preventing performance of discoloration of silver and copper and migration, etc. CONSTITUTION:An epoxy resin composition obtained by incorporating (A) an epoxy resin with (B) 2-vinyl-4,6-diamino-s-triazine and (C) a filler to form the first solution, dissolving the resultant solution and (D) poly-p-phenol having preferably 25-70 average polymerization degree and (E) an imidazole compound in an adequate amount of an organic solvent, e.g. butylcarbitol acetate, to form the second solution, and mixing the first and second solutions just before the use. The compounding ratio of the components based on 100pts.wt. component (A) is preferably as follows; 5-20pts.wt. component (B), 10-40pts.wt. component (D) and 0.025-10pts.wt. component (E).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an epoxy resin ink composition. This material has excellent electrical insulation, moisture resistance, heat resistance, chemical resistance, and adhesion, and also has silver or copper discoloration and migration prevention properties, and also has medium- to high-temperature fast curing properties, so it can be used for printed circuit boards. It can be used for manufacturing etc.

(Prior Art) Several methods are known for manufacturing conventional printed circuit boards.

That is, (A) screen printing a desired circuit using silver, platinum, palladium conductors, resistors, capacitors, etc. using glass frit as a binder on an inorganic insulating substrate made of an inorganic material such as ceramic or glass as a base material. The so-called thick film hybrid integrated circuit board is formed by forming and firing at high temperature.

(B) Laminated insulating base 8Fj based on an organic material such as paper/phenol, paper/epoxy, glass-epoxy, etc., with phenol resin, phenol-modified xylene resin, epoxy resin, etc. as a binder, silver thread conductor, resistor A printed circuit board/board made by forming the desired circuit by screen printing and baking at medium to high temperature.

(C) A printed circuit board in which a desired circuit is formed by etching the copper foil of a copper-clad laminate in which copper foil is laminated to a laminate made of the same organic material as a base material.

Incidentally, the surface of the conductive circuit formed by each of the above methods is usually exposed in a planar manner and is therefore susceptible to the influence of the environmental atmosphere. That is, accidents are likely to occur due to corrosion of the conductor circuit portion due to adhesion of conductor-corrosive impurities or moisture contained in the atmosphere to the conductor.

In order to prevent accidents caused by such factors and further improve the reliability of circuits, a method is generally used and practiced in which a protective coating called a permanent resist is formed on the circuit by screen printing or the like.

(Problems to be Solved by the Invention) In this case, the protective coating film is required to have properties such as electrical insulation, moisture resistance, chemical resistance, adhesion, and hardness.

Furthermore, in the thick film hybrid integrated circuit boards and printed circuit boards, the formed circuits are often minute and complex, so when plating with nickel, gold, copper, solder, etc., short circuits due to plating may occur. I'm used to waking up.

In order to prevent this, a method has been adopted today in which a protective coating called resist ink is applied by screen printing to areas where plating is not needed, and after curing to form a coating film, plating is applied only to the areas where it is necessary. In this case, the protective coating is required to have functions as an ink such as viscosity, stringiness, and thixotropic properties suitable for screen printing and the like.

Discoloration and migration of silver and copper conductor circuits, which occur when voltage is applied under high temperature and high humidity environmental conditions, are a problem due to the recent advances in electronic equipment, such as smaller size, lighter weight, higher density, and higher reliability. This has become a problem today due to high demands.

With the exception of triazine resin or bis-maleicide-triazine resin, there are hardly any materials for protective coatings that have the ability to prevent discoloration and migration of silver and copper conductors.

Conventionally, as a protective coating with the above-mentioned characteristics and functions,
Sintered glass-based paints, heat-curable epoxy resins, phenolic resin-based paints, melamine resin-based paints, epoxy-melamine resin-based paints, silicone resin-based paints, and ultraviolet curable resin-based paints are known, but with the exception of glass-based paints, All of these are insufficient in preventing discoloration and migration of silver and copper conductors.

Even with the above-mentioned triazine resin system and bis-maleicide-triazine resin system, there are problems in handling such as curing conditions (temperature, time) and pot life, and it cannot be said that they are in a satisfactory state.

In view of these circumstances, the inventors of the present invention have conducted extensive research to find a coating that has a long pot life, prevents discoloration and migration of silver and copper conductors, and has various properties that are satisfactory as a protective coating. A functional two-component epoxy resin ink composition has been discovered.

(Means for Solving the Problems) That is, the epoxy resin ink composition of the present invention contains a small amount (both 2-vinyl 4
,6-diamino-S-)riazine, 1 part of polyvinyl-para-phenol 10-40ii, and an imidazole compound in a ratio of 25 to 10 parts by weight.

When the composition of the present invention is heated, the vinyl group of 2-vinyl-4,6-diamino-s-)riazine is cleaved and undergoes a polymerization reaction, and the two amino groups attached to the triazine ring are also converted into epoxy groups due to the presence of the imidazole compound. Reacts with resin.

Additionally, the hydroxyl group of polyvinyl-bara-phenol also easily reacts with the epoxy resin due to the action of the imidazole compound.

Furthermore, the epoxy resin itself reacts with an imidazole compound in addition to the above-mentioned 2-vinyl-4,6-diamino-S-triazine and polyvinyl-bala-phenol, and is cured by anionic polymerization. As a result of these controlled reactions occurring almost simultaneously, a coating film is produced that exhibits the characteristics necessary for circuit board inks, such as heat resistance, chemical resistance, color fastness, and anti-migration function.

However, the pot life of this composition is unfortunately short, and in order to make it practical, it must be used in the following configuration.

Namely, epoxy resin and 2-vinyl-4,6-diamino-
s-) Mix riazine, filler, etc. uniformly to prepare solution A, then dissolve polyvinyl-para-phenol and imidazole compound, etc. in an appropriate amount of an organic solvent (e.g., butylcarpitol-acetate, etc.). The resulting solution is designated as Solution B, and Aijjl and Solution B are mixed immediately before use.

Although the composition according to the present invention has the drawback that it has a short pot life and cannot be stored for a long period of time, and is therefore impractical, this drawback can be overcome by handling it as a two-component composition as described above.

The performance of the protective coating after curing is extremely high, and the curing speed is comparable to that of ultraviolet curing resin paints (which have been frequently used in the field in recent years due to their fast curing speed).

The composition according to the present invention can be used as a protective coating for thick-film hybrid integrated circuit boards, printed circuit boards, etc., and as an insulating layer for multiple (multilayer) wiring.

Epoxy resins suitable for the practice of this invention include polyglycidyl ethers of polyhydric phenols, such as bisphenol-A-
These include diglycidyl ether, bisphenol-F-diglycidyl ether, epoxidized phenol novolak resin, and epoxidized resol novolac resin.

In the present invention, the filler can be added in a proportion of up to 100 parts by weight per 100 parts by weight of the epoxy resin.
Typical examples are barium sulfate, calcium carbonate,
These include talc, mica, silica, aluminum hydroxide, alumina, etc., and these can be used alone or in combination of two or more. Methods for reacting lorides other than these [J
, Am, Chem, Soc,, 80.988 (19
58)], a method for reacting dicyandiamide with β-dimethylamino-propionitrile (French Patent No. 1563255), and 1,2-di(4'',6°-diamino-5-triazidou(2)') - Method of heating cyclobutane under reduced pressure (Japanese Patent Publication No. 35068/1983)
It can be manufactured by etc.

The amount used is 5 to 2 parts per 100 parts by weight of epoxy resin.
0 parts by weight, particularly preferably 7 to 15 parts by weight. If the amount of 2-vinyl-4,6-diamino to 5-1-riazine used is outside the above range and is too small, it will not have the effect of preventing discoloration and migration of silver and copper, the curing speed will be low, and practicality will be lost. be exposed. If the amount is too high, the cured coating will be brittle and lack functionality as a protective coating.

Prevents intrusion (during the curing of thin pattern coatings).

The average degree of polymerization is preferably in the range of 25 to 70.

Typical imidazole compounds used in the present invention are 2-methyl-imidazole, 2-ethyl-4
-methyl-imidazole, 2-phenylimidazole,
2-undecylimidazole, 2-heptadecyl imidazole, 2-phenyl-4-methylimidazole, 1-position cyanoethyl compounds of these 2-substituted imidazoles,
Carboxylate salts of these imidazole compounds, 2,4-diamino-6=(2-methylimidazolyl-(1)) -
Ethyl-3-triazine, 2,4-diamino-6-(2
-ethyl-4-methylimidazolyl-(1,+1-ethyl-3-triazine, 2,4-diamino-6-(2-
Methylimidazolyl-(1)) -ethyl-5-triazine-isocyanurate, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-3-hydroxymethylimidazole, etc. A fast-curing composition can be obtained by using one type or a combination of two or more types of highly reactive imidazole compounds. Imidazole compounds, such as 2-methylimidazole, 2-ethyl-4-methylimidazole, etc., which are soluble in polyvinyl-para-phenol solvents, such as butylcalcithyl acetate, etc., are used as dissolved in the solvent, and imidazole compounds that are insoluble in the solvent are used. The compound is dispersed in a polyvinyl-bara-phenol solution using a kneader such as a three-roll mill so that the particle size is 10 microns or less.

The curing temperature of the composition in the present invention is 130 to 20
It is in the range of 0°C.

(Example) Each composition in the Examples and Comparative Examples was uniformly dispersed and kneaded using a three-roll mill so that the particle size was 10 microns or less.

Performance tests were conducted on the compositions prepared according to Table 1, and the results are shown in Tables 2 and 3.

The mixing ratio of liquid A and liquid B should be determined according to the performance, but in this example, the weight ratio of liquid A: liquid B -
1,00: 13.6. Comparative Examples 1 to 3 are -liquid epoxy resin ink compositions. The commercially available product of Comparative Example 4 is an ultraviolet curing solder resist UR3000 manufactured by Sunf Chemical Industry Co., Ltd.

Table 2 Performance test of composition “1 fruit*l: 80W/c+n ozone-less high-pressure mercury lamp,
Irradiation with 3 tubes, furnace speed: 4m/old n *2: Store A and B separately *3: Pot life after mixing A and B in specified amounts (Note) (1) 150°C The mixture is placed on a hot plate adjusted to a temperature of approx.
．． Place 3gr and spread it thinly with a metal spatula, and the time until there is no thread between the spatula and the mixture.

(2) Time until the viscosity reaches twice the initial value as measured by a B-type rotational viscometer.

However, a coating film with a thickness of 20μ is formed by screen printing.
, which was cured at 150°C for 15 minutes.

* Commercially available resist: An ultraviolet curable ink composition. Curing conditions: 80W/cm ozone-less high-pressure mercury lamp 3
The furnace was irradiated at a speed of 4 m/old n.

(Note) (3) The test piece was placed at a temperature of 60°C, a humidity of 95%, and an applied voltage of D.
Measurements were made at predetermined intervals under the condition of C30V.

(The copper foil of the 41N HM A standard
A test piece obtained by forming a 3 mm interdigitated electrode circuit, screen printing different formulations on the circuit, and curing the circuit was left under the above conditions for 500 hours.

(Screen-print a comb-shaped electrode circuit with a conductor line width of 0.5 mm and a conductor spacing of 0.3 mm using a silver powder-phenol resin paste on a 51NIEM^ standard x PC laminated board, 1
After baking at a temperature of 50°C for 30 minutes, each different formulation was screen printed on the circuit, and the test piece obtained by heat curing was left under the conditions described in (3) above for 100 hours. case.

(6) Screen-print a comb-shaped electrode circuit with a conductor line width of 0.5+nn+ using silver/palladium powder-glass paste on a ceramic substrate, bake it at a temperature of 700°C for 2 hours, and then print each layer on the circuit. When a test piece obtained by screen printing the formulation and heat curing it was left under the conditions of (3) above for 500 hours.

(Measurements were made on aluminum plates on which protective films were formed by screen printing each of the different formulations in accordance with 71 JIS-C-2103.

(8) The test piece prepared by the method in (4) above was heated to 260°C.
After being immersed in a molten solder bath for 30 seconds, the appearance of the coating film was observed for blistering, peeling, etc., and a cross-cut beer test was conducted in accordance with J15-D-0202.

(9) Changes in the biofilm were observed after the test piece prepared by the method (4) above was immersed in a 10% sulfuric acid solution and a 10% caustic soda solution for 120 hours.

00) The test piece prepared by the method (4) above was
Pencil hardness was measured according to D-0202.

Procedural amendment (spontaneous) July 24, 1980 Patent Application No. 133560 2, Title of invention Epoxy resin ink composition 3, Person making the amendment Relationship with the case 2 Representative applicant 4, Subject of the amendment Detailed Explanation of the Invention in the Specification 5, Contents of Amendment (1) [Murray, l+

Claims (3)

[Claims] (1) An epoxy resin ink composition containing at least an epoxy resin, polyvinyl-para-phenol, 2-vinyl-4,6-diamino-s-triazine, and an imidazole compound. (2) At least epoxy resin and 2-vinyl-4,6-
An epoxy resin ink composition in which solutions obtained by dissolving a mixture containing diamino-s-triazine and a mixture containing polyvinyl-para-phenol and imidazole in a suitable organic solvent are prepared separately, and the two are blended immediately before use. thing. (3) For 100 parts by weight of epoxy resin, 2-vinyl-
5 to 20 parts by weight of 4,6-diamino-s-triazine,
The epoxy resin ink composition according to claims 1 and 2, which contains 10 to 40 parts by weight of polyvinyl-para-phenol and 0.025 to 10 parts by weight of an imidazole compound.