JPH0192376A - Resist ink for electroless plating - Google Patents

Abstract

PURPOSE:To manufacture resist ink for electroless plating causing no crack to fine pattern by incorporating phenolnovolak-type epoxy resin, aliphatic polyol polyglycidyl ether, phenolnovolak resin, montmorilonite organic complex compound, thermosetting reaction-accelerating catalyst, and organic solvent. CONSTITUTION:Resist ink is prepared by using [A] phenolnovolak-type epoxy resin, [B] aliphatic polyol polyglycidyl ether, [C] phenolnovolak resin, [D] montmorilonite organic complex compound, [E] thermosetting reaction- accelerating catalyst, and [F] organic solvent. Moreover, respective contents of the above components are regulated so that the component B is about 10-100wt.% based on the component A, the number of phenolyc hydroxyl groups in the component C per piece of epoxy group in the components A, B is about 0.5-2.0, the component D is 3-25wt.% based on the total content of the components, A, B, C, and E, the component E is about 0.5-10wt.% based on the total content of the components A, B, and C, and the component F is about 20-80wt.% based on the total content of the components A, B, and C.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a resist ink used when manufacturing printed circuit boards by electroless plating.

(Prior art and problems) Conventionally, resists for electroless plating have been made using two liquids, for example, consisting of a main ingredient containing an epoxy resin, an inorganic filler, and an organic solvent, and a curing agent containing an aromatic polyamine compound and an organic solvent. Warming type resist inks are known.

Although conventional products have achieved fairly high performance in terms of chemical resistance, adhesion to substrates, and heat resistance, their performance is still not sufficient. In particular, the following drawbacks have been pointed out compared to conventional products.

■ Ink viscosity, especially thixotropy, changes easily (
, it is difficult to obtain stable printability.

■ When screen printing, pattern reproducibility is not sufficient, making it difficult to handle fine patterns.

That is, when a pattern has a line width of approximately 200 μm, its reproducibility is insufficient.

■ The chemical resistance of the cured resist film is still insufficient under today's harsh chemical processing conditions.

■ During electroless plating, copper tends to precipitate and adhere to the plating resist, causing the so-called "copper flaking" phenomenon. When the deposited copper grows, it causes a short circuit between lines.

The present inventors have previously developed a resist ink for electroless plating that overcomes these drawbacks, and have filed a patent application (patent application filed in 1983).
1-308926).

Although this resist ink was satisfactory, subsequent studies revealed that there was a tendency for cracks to occur in the fine patterns when various stresses were applied during substrate manufacturing, and measures were needed to deal with this problem. A new request has been made.

(Object of the invention) In order to meet the above-mentioned demands, the present invention aims to provide a resist ink that does not cause cranking in fine patterns and has good chemical resistance and copper-free property. It is.

(Structure of the invention) The present invention is as follows.

The following components [A] to [F] [A] Phenol novolac type epoxy resin [B] Aliphatic polyol polyglycidyl ether [C] Phenol novolac resin [D] Montmorillonite organic composite, [E] Thermosetting reaction accelerating catalyst [F] ]A resist ink for electroless plating containing an organic solvent.

The present invention having such a configuration was completed based on the following findings obtained by the present inventors.

(2) To prevent the occurrence of cracks in fine patterns, it is basically important that the resin constituting the resist film has flexibility.

■ In order to improve the chemical resistance of the resist film and to prevent the phenomenon of copper flaking on the resist film, it is basically important to improve the chemical resistance of the resin that makes up the resist film.

(2) If the resin constituting the resist film has flexibility, chemical resistance generally decreases.

(2) By using a specific combination of components in the present invention, particularly aliphatic polyol polyglycidyl ether, cracking and copper flaking phenomena can be effectively prevented.

Hereinafter, the configuration of the present invention will be explained in detail.

Component (A) Phenol novolak type epoxy resin is a phenol novolak resin obtained by condensing phenols such as phenol, cresol, and bisphenol A with formaldehyde, etc. in the presence of an acidic catalyst, and further condensing the resin in the presence of an alkali catalyst. It is obtained by reacting with epichlorohydrin, and preferably has an epoxy equivalent of 170 to 250.

Specific examples include Epicoat 154 (manufactured by Yuka Shell Epoxy Co., Ltd.).

Component [B] Aliphatic polyol polyglycidyl ether is obtained by reacting polyols such as (poly)ethylene glycol, 1,6-hexanediol, and trimethylolpropane with epichlorohydrin in the presence of an alkali catalyst. , preferably having an epoxy equivalent of 100 to 400.

Specifically, (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, ■, 4-butanediol diglycidyl ether, 1
．． Examples include 6-hexanesiol diglycidyl ether, (poly)glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, and halogenated products thereof. Evolite 80MF (
manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.), etc.

Component [C] Phenol novolak resin is obtained by condensing phenols such as phenol, cresol, and bisphenol A with formaldehyde, etc. in the presence of an acidic catalyst, and preferably has a hydroxyl equivalent of 100-150 and a softening point. The temperature is 60 to 130°C.

A specific example of a commercial product is BRG-556 (Showa Kobunshi Co., Ltd.)
Made in Japan.

Component [D] Montmorillonite organic complex is a complex of montmorillonite and an organic substance, and commercially available products include Olben [manufactured by Shiraishi Kogyo Co., Ltd.], Nini D Olben [same as above], and Nisben [Hojun]. manufactured by Yoko Co., Ltd.).

Component [E] The catalyst for promoting thermosetting reaction is the epoxy resin of [A] and [
B] has the effect of accelerating the thermosetting reaction of the phenol novolak resin.

Specific examples include 2-methylimidazole, 2-phenylimidazole, 2-heptadecylimidazole, 2-undecylimidazole, 2-ethyl-4-methylimidazole, 2,4-dimethylimidazole, 2-isopropylimidazole, 2-phenyl. -4-methylimidazole and the like can be mentioned. Further, triphenylphosphine, 1,8-diaza-bicyclo(5.4.0)undecene-7, or its phenol salt, 2-ethylhexanoate, carbonate, etc. can also be used.

Component [F] The organic solvent is the epoxy resin of component [A] and the component [B].
of phenolic novolak resin, preferably at a temperature at which the curing reaction of the ink is quite high (usually 150
It has a relatively high boiling point because it is carried out at a temperature of ~250°C).

Specifically, cellosolves such as ethyl cellosolve, butyl cellosolve, and phenyl cellosolve, their acetate esters, carpitols such as ethyl carpitol, butyl carpitol, and phenyl carpitol, and aralkyl alcohols such as benzyl alcohol may be mentioned. Can be done.

These can be used in one type of vehicle or in combination of two or more types.

The organic solvent used in the base resin and the organic solvent used in the curing agent system may be the same or different.

The content of each component in the present invention is preferably as follows.

Component [B] is 10 to 100% by weight based on component [A]
It is. In component [C], the number of phenolic hydroxyl groups in component [C] is 0.5 per epoxy group in components [A] and [C].
Use at a ratio of ~2.0 pieces.

Component [D] is component [A], [B], [C] and [E]
3 to 25% by weight based on the total amount.

Component [E] is 0.5 to 10% by weight based on the total amount of components [A], [B] and [C]. Component [F] is 20 to 20% of the total amount of components [A], (I3) and [C].
It is 80% by weight.

When the resist ink has a content within the above range, particularly excellent performance can be exhibited. Especially component [B]
The aliphatic polyol polyglycidyl ether is the above 10-
When the amount is in the range of 100% by weight, an excellent resist ink having both crank resistance and chemical resistance and reproducible screen printability can be obtained.

When component [B] is less than 10% by weight relative to component [A], it is difficult to achieve flexibility, and when the weight is 100%, chemical resistance tends to decrease. .

In the present invention, in addition to the above components [A] to [F], other components may be blended as desired.

For example, in order to facilitate identification of the resist film, a blue pigment, a green pigment, carbon black, or the like may be appropriately added as a coloring agent. The blending amount of the colorant is usually in the range of 0.5 to 10% by weight based on components [A] to [E].

The resist ink of the present invention is preferably manufactured by separately preparing the base agent and the curing agent system as described below, and then mixing the two.

[Main agent]

Approximately 50 to 120 phenol novolac type epoxy resin
C. to fluidize and measure a predetermined amount, add a predetermined amount of aliphatic polyol polyglycidyl ether, an organic solvent, and a montmorillonite organic composite, and mix uniformly using a day silver or the like. After cooling the obtained mixture to room temperature, fillers are thoroughly mixed and dispersed using a kneading machine such as a three-roll mill to form an ink.Finally, a predetermined amount of organic solvent is added as needed, and dye Mix well with silver or the like to form a main ingredient that exhibits a predetermined viscosity.

As described above, it is preferable to add the montmorillonite organic composite filler used in the present invention to the main agent, but it is not necessarily limited to this, and in some cases, it may be added to the curing agent system. It is also possible to use

[Curing agent system]

Separately from the above-mentioned main agent, the phenol novolak resin is usually added to an organic solvent preheated to about 50 to 130°C with stirring to dissolve it, and then a catalyst for accelerating the thermosetting reaction is added and homogenized to form a curing agent. system.

The base agent and curing agent system prepared as described above are each weighed out and thoroughly mixed using a stirrer or the like to make the mixture uniform, thereby producing a resist ink.

Catalysts for promoting thermal curing reactions are usually added and mixed into the curing agent system in advance, but if they are not, e.g.
Prepare the catalyst as a solution dissolved in an organic solvent,
This catalyst solution can also be added at the same time when the base agent and curing agent system are mixed to produce an ink.

When manufacturing a resist ink by mixing the base agent and the curing agent system, the amount of each used is 0.5 phenolic hydroxyl group of component [C] per epoxy group of components [A] and [B]. It is preferable to use a proportion of ~260 pieces, preferably 0.8~1.2 pieces.

When used within this range, the cured resist film will have good crank resistance, heat resistance, and chemical resistance.

(Effects of the Invention) As is clear from the results in Table 3 below, the resist ink of the present invention is excellent in crack resistance, chemical resistance, and non-copper flaking property, and electroless plating that has all of these properties. It is extremely useful as a resist for commercial use.

(Examples and Comparative Examples) Example 1.2 and Comparative Example 1.2 Base ingredients [A] to [II] were prepared according to the formulations shown in Table 1, respectively. Separately, a curing agent system was prepared with the formulation shown in Table 2. Each of the obtained main ingredients and each curing agent system were blended in the combinations shown in Table 3 to produce resist inks.

When the characteristics of this resist ink were investigated, the results shown in Table 3 were obtained.

The method for measuring the characteristics is as follows.

[Crank resistance]

Screen printing was performed on an ACL substrate (10 (ln x 500 x 1.Q@m) with a line width of 150 μm and a thickness of 20 μm, and after curing (150°C, 30 minutes), the center part was placed at both ends in the longitudinal direction. Warp it 200mm higher than that and measure whether a crank occurs.

[Chemical resistance and copper content]

After curing the resist pattern printing, further chemical roughening,
Electroless plating treatment is performed to improve chemical resistance to chemical roughening solutions and the number of copper particles (1crA) that can be observed with a 20x magnifying glass.
(per hit) was measured as the amount of copper sprinkled.

[Notes (Tables 1 and 2)] (1) Phenol novolak type resin manufactured by Yuka Shell Epoxy■, epoxy equivalent 176-181 (2) Glycerin diglycine ether manufactured by Kyoeisha Yushi Chemical Industry, epoxy equivalent 140-170 (3) Manufactured by Kyoeisha Oil and Fat Chemical Industry
Trimethylolpropane triglycidyl ether amount 135-165 (4) Montmorillonite organic composite manufactured by Shiraishi Kogyo ■ (5
)Mitsubishi Kasei Carbon blank (black pigment) (6)
Showa Kobunshi side type phenol novolac resin, softening point 8
0℃

Claims (3)

[Claims] (1) The following components [A] to [F] [A] Phenol novolak type epoxy resin [B] Aliphatic polyol polyglycidyl ether [C] Phenol novolac resin [D] Montmorillonite organic composite [E] Thermosetting reaction accelerating catalyst [F] Resist ink for electroless plating containing an organic solvent. (2) Component [A] Phenol novolac type epoxy resin, [B] Aliphatic polyol polyglycidyl ether, [
D] montmorillonite organic composite, [F] main agent containing organic solvent, [C] phenol novolac resin, [E
[Thermosetting reaction accelerating catalyst, [F] Organic solvent, if desired [
D] The resist ink according to claim (1), which is blended with a curing agent system containing a montmorillonite organic composite. (3) The resist ink according to claim (1), which contains component [B] 10 to 100% by weight of aliphatic polyol polyglycidyl ether based on [A].