JPS63218776A - Metx resistant solder resist ink composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a plating-resistant stain-resistant ink composition. For more information, please see plating-resistant solder resist ink that provides a film with excellent chemical resistance (plating liquid resistance), heat resistance, and adhesion to the board that can be used in the manufacture of printed circuit boards using electroless metal plating (chemical plating). Related to composition〇 [Prior art] Generally, the film thickness of the conductor circuit of a printed circuit board is 30 to 3
511m is required. Furthermore, this conductor circuit tensile strength 2
1 requires 9/- or more. Electroless metal plating that satisfies this requirement can generally only be obtained in a strong alkaline bath with a pH of 12 to 130 (60 to 80°C), and the deposition rate of electroless plating is approximately 0.5 to 5 μm/hour. Therefore, in order to obtain a thickness of 30 to 35 μm, it is necessary to conduct plating for a long time.

Therefore, when forming a conductor circuit on such a circuit board, the resist film used for circuit protection must be able to withstand high temperature strong alkaline plating solution for a long time. In addition, it must have good printability on the board, good adhesion between the board and the conductor, and must be able to withstand temperature and be easy to handle when soldering.

Various resist films for protecting conductor circuits have been known in the past, but an epoxy resin composition that satisfies the above points and is suitable for use as an easy-to-use overnight solder resist ink has not yet been developed.

In other words, most conventional solder resists are two-component, consisting of a base agent and a hardening agent, and currently there is no known molded solder resist that fully satisfies soldering heat resistance, etc. be.

[Problem that the invention seeks to solve]

The purpose of the present invention is to prevent the resist film from dissolving in the solvent, whitening, sagging, cracking, or swelling even when immersed in an electroless metal plating solution for a long time, and to have excellent adhesion to base materials and conductors. The object of the present invention is to provide an ink composition for an overnight solder resist that has good heat resistance, can withstand soldering work well, and has little thermal deterioration at high temperatures.

In other words, in the conventional printed circuit board manufacturing process, for example, a semi-additive method was used in which a conductor pattern was formed on a copper-clad laminate board by etching, this was protected with a solder resist ink film, and only the through-holes were formed by electroless plating. In most cases, poor adhesion occurs in the resist film on the conductor pattern connected to the through-hole, and this area bulges during soldering. This is because, as mentioned above, since the resist film is immersed in a high-temperature, strongly alkaline electroless plating solution for a long time, moisture enters through the resist film, reducing the adhesive strength between the resist film and the conductor. Also, if the heat resistance is not sufficient, the film will become brittle if heat treated for a long time.
Blistering or peeling of the paint film occurs.

[Means for solving problems]

As a result of various studies, the inventors of the present invention have determined that Dracino 6
It has been found that the above problem can be solved by using -methylamino-8-) riazine.

That is, the present invention provides 100 parts by weight of the epoxy compound (2), 5 to 35 parts by weight of 2,4-dihydrazino-6-methylamino-s-trifle (2), (/→ filler) 3 to 40 parts by weight, and) the thixotropic agent is in a proportion of O, S to 10 parts by weight.

The epoxy compound (A) used in the present invention is a compound having an average of two or more epoxy groups per molecule and is liquid at room temperature, such as bisphenol A.

Polyglycidyl ether obtained by reacting a polyhydric alcohol such as bisphenol F with epichlorohydrin in the presence of a basic catalyst can be used.

2,4-dihydrazino-6 used in (b) of the present invention
-Methylamino-S-) lyazine has the following structure and a curing accelerator can be used in combination if necessary.

Examples of curing accelerators include quaternary ammonium salts, quaternary
Examples include class phosphonium salts, amine compounds, and the like. 2,4-dihydroxy-6-methylamino-8 which is a curing agent
- Triazine is used in an amount of 5 to 35 parts by weight, preferably 15 to 25 parts by weight, per 1 part of epoxy compound 100'ii. If it is less than 5 parts by weight, curing will be insufficient, and if it is more than 35 parts by weight, the coating performance will deteriorate, which is undesirable. Aluminum oxide,
Silica, TiO! It is a solid powder such as. The amount of filler used is 3 to 40 parts by weight per 100 parts by weight of the epoxy compound.

This is because when the amount is more than 40 parts by weight, the coating film forming properties are poor, and when it is less than 3 parts by weight, there is no effect of improving the properties. The average particle diameter of the filler is preferably about 0.5 to 10 μm.

Note that the filler serves to improve the printability of the solder resist ink and to improve the mechanical properties of the cured solder resist.

The thixotropic agent ()→ is 0.5 to 10 parts by weight per 100 parts by weight of the epoxy compound. used. If the amount of thixotropic agent is outside this range, the screen printability of the ink will deteriorate and it cannot be put to practical use.

The composition of the present invention may be modified by adding various known additives as necessary, without detracting from the spirit of the present invention.

Examples include additives such as curing accelerators, leveling agents, anti-settling agents, coupling agents, monoepoxy compounds, colorants, pigments, antifoaming agents, adhesion agents, and solid solvents with a boiling point of 100°C or higher. be able to.

The composition of the present invention is produced by adding the above-mentioned main components and additional components and thoroughly mixing the composition with a triple roll or the like.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to examples thereof.

Examples 1 to 3 and Comparative Examples 1 to -@1 The compositions shown in the table were sufficiently pre-kneaded, passed through three times with a ceramic triple roll, and formed into a film on a full Darrehole polyimide substrate using a screen printing machine. Thickness is approximately 25μm
The protective film was coated on the copper-clad printed wiring board by applying the coating so as to give a protective film and curing by heating at 180° C. for 8 hours. Using this as a test piece, the coated substrate was immersed in a fire for 20 hours, then removed from the plating solution, washed with water, and dried at 90°C for 30 minutes. The surface of the resist film was observed using a microscope.

O: No abnormality in the paint film. ×: Whitening, dissolution, and blistering of the paint film. Adhesion: The dried paint film was subjected to an interstitial adhesion test.

Solder resistance: Dry coating film is molten solder at 260℃ 1
It was immersed for a minute and the condition of the coating film was evaluated.

0: No abnormality in the appearance of the coating film ×... Peeling of the coating film, melting heat deterioration test): The condition and adhesion of the coating film after aging in Drying 6 at 230° C. for 72 hours was evaluated.

○...No abnormality ×...Full of coating film (margin below peeling C) Table 1 *1 Yuka Shell Epoxy Co., Ltd. gg-szs*2 2.4
-dihydrazino-6-methylamino-S-) riazine*3 2t4-diamino-6(2'-methylimidazole α))ethyl-s-triazine*4 Tatsumorisha Seki Silica powder■■Average particle size IPm*5
Made by Nippon Aerosil, ultrafine powder silica, Aerosil 20
0 Average particle size 12

Claims (1)

[Scope of Claims] Containing the following components (a), (b), (c), and (d),
(a) Epoxy compound (b) 2,4-dihydrazino-6-methylamino-S-
triazine (c) filler (d) thixotropic agent and (b) 2,4-dihydrazino-6-methylamino- to 100 parts by weight of the epoxy compound (a);
A plating-resistant solder resist ink characterized in that the proportion of S-triazine is 5 to 35 parts by weight, (c) the filler is 3 to 40 parts by weight, and (d) the thixotropic agent is 0.5 to 10 parts by weight. Composition.