JPH05106056A - Partial plating method - Google Patents

Abstract

PURPOSE:To carry out partial plating harmless to stock with excellent environmental safety without deteriorating the masking performance of conventional resist ink. CONSTITUTION:A layer of resist ink based on at least one kind of temp. sensitive polymer selected among poly-N-methylacrylamide, poly-N-- isopropylacrylamide, poly-N-t-butylacrylamide, poly-N-hydroxyethylacrylamide and poly-N,N-dimethylacrylamide is formed on a part not requiring plating. After etching, the resist ink layer is removed and electroless plating is carried out to complete partial plating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial plating method for performing on plastics, printed wiring boards and the like.

[0002]

2. Description of the Related Art The partial plating method is generally widely applied to the production of circuit patterns on printed wiring boards. Specifically, the method of masking with insulating tape, photoresist, resist ink, etc., plating can be performed. Resin and non-formable resin forming two-color molding method, catalyst-containing resin and resin-free resin forming two-color molding method, conductive paint or organic paint applied and plated on it Methods etc. are known. In particular, the partial plating method using the above resist ink is capable of extremely fine masking and is excellent in operability and the like, and is therefore widely used in various manufacturing fields such as plastic plating and the production of printed wiring boards. ..

However, in the partial plating method using a conventional resist ink such as an alkali-soluble resist ink or a solvent-soluble resist ink, an alkaline aqueous solution or an organic solvent is used to remove these resist ink layers after the plating process is completed. Must be used. For this reason,
In the method using the resist ink, it is necessary to consider the influence on the material to be plated, and there is a problem in the working environment due to an organic solvent that is harmful to the living body and a problem in wastewater treatment.

From the above viewpoint, at present, the above-mentioned problems do not occur without impairing the masking performance of the conventional resist ink, that is, the adhesiveness to the material, the chemical resistance to the processing liquid, the resist peeling property and the like. Development of a partial plating method using resist ink has been earnestly desired.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a partial plating method which is harmless to the material and is excellent in environmental safety without impairing the masking performance of the conventional resist ink.

That is, in the present invention, poly-N-methyl acrylamide, poly-N-isopropyl acrylamide, and
A layer of a resist ink containing, as a main component, at least one selected from temperature-sensitive polymers consisting of poly-N-t-butylacrylamide, poly-N-hydroxyethylacrylamide and poly-N-N-dimethylacrylamide. The present invention relates to a partial plating method characterized in that the resist ink layer is formed in advance, the resist ink layer is removed after the etching treatment, and then the electroless plating treatment is performed.

As a result of intensive studies to develop a novel partial plating method, the present inventors have found that the above problems can be solved when a specific temperature-sensitive polymer is used as a resist ink, and the present invention is realized. It came to completion.

The present invention will be described in detail below.

The temperature-sensitive polymer in the present invention is usually water-soluble and has a unique property that it is insoluble in water at a certain temperature or higher. As such a polymer, poly-N-methylacrylamide, Poly-N-
Isopropyl acrylamide, poly-N-t-butyl acrylamide, poly-N-N-dimethyl acrylamide,
Examples thereof include poly-N-hydroxyethyl acrylamide, and a copolymer containing at least one of these as a main component is used as a resist ink. The water-soluble / water-insoluble transition temperature of the above-mentioned copolymer can be arbitrarily set by changing the type of the monomer to be copolymerized, the mixing ratio, and the like.

A resist ink having the above components is applied to a material and dried at about 20 to 60 ° C. for 1 to 3 hours,
Then, it is left at room temperature for about 1 to 6 hours. Next, degreasing and washing with hot water are carried out in accordance with a conventional method, but these operations must be carried out at the transition temperature of the resist ink used or higher.
The material applicable in the present invention may be any known resin, for example, ABS resin, polyacetal resin, polyamide resin, polycarbonate resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyphenylene oxide resin. , Various resins such as polysulfone resin, polyether sulfone resin, polyarylate resin, polyimide resin, polyamideimide resin, polyphenylene sulfide resin, and polypropylene resin. Further, as the metal, for example, a metal or alloy such as copper, nickel, stainless steel, or brass can be applied.

Then, an etching treatment, a neutralization treatment, a catalyst application and an activation treatment are sequentially carried out in accordance with a conventional method. Here, the resist ink layer may be removed after any of the steps as long as it is after the etching treatment. However, as described above, each treatment is performed at a temperature equal to or higher than the transition temperature until the resist ink layer is removed from the material. As a method of removing the resist ink layer, the resist ink layer can be easily removed in a water washing tank or the like set to a water temperature below the transition temperature.

When the resist ink layer is removed after the catalyst is applied, it is necessary to completely remove the resist ink layer from the material before performing electroless plating. At this time, if palladium remains on the surface of the material even a little, an electroless plating film will be formed on that part, so it is necessary to pay attention to the removal treatment. Usually, after activation of a catalyst, sulfuric acid, hydrochloric acid, ammonia, activation treatment using an activation solution such as caustic soda provides activated palladium necessary for electroless plating. When a halogenated compound is added, the effect of dissolving and removing the catalyst in the activation solution is enhanced, unnecessary residual palladium is completely removed, and more excellent partial plating can be performed. Examples of the halogenated compound that can be used in this case include sodium chloride, potassium chloride, sodium fluoride, potassium fluoride, ammonium fluoride, potassium bromide, potassium iodide and the like. The amount of the halogenated compound added cannot be uniformly specified depending on the conditions of the catalyst application step and the like, but usually, one or more of these halogenated compounds are added to the activation solution in an amount of 0.1 to 10 g / Add about l.

When the material which has been subjected to the above-mentioned removal of the resist ink layer and the pretreatment of the usual electroless plating is subjected to the usual electroless plating, a plating film is formed on the portion where the resist ink layer is applied. A product in which the so-called partial plating is formed is obtained. The electroless plating coating material in this case is not limited as long as it is used in ordinary electroless plating, but electroless copper plating, electroless nickel plating, etc. are particularly preferable.

[0014]

According to the partial plating method of the present invention, the following excellent effects can be obtained.

(1) Since etching is performed only where plating is required, and plating is performed from above, high adhesion strength can be obtained between the material and the plating film.

(2) Since the resist ink layer in the portion not requiring plating can be easily removed, the surface of the material itself can be fully utilized.

(3) By masking, the coating material can be directly coated on the resin surface, and in this case, a stronger adhesion strength can be obtained as compared with coating on the plating film.

(4) Since the temperature-sensitive polymer is used as the resist ink, the resist ink layer can be easily removed with water, and there is no fear of environmental pollution such as a solvent, resulting in excellent safety. Demonstrate.

[0019]

EXAMPLES Examples will be shown below to clarify the features of the present invention. The present invention is not limited to the examples.

Example 1 A resist ink having a water-soluble / water-insoluble transition temperature of 40 ° C.
Using a copolymer containing poly-N-methylacrylamide as the main component, the ABS resin plate (10 cm x 10 cm
X 0.3 cm) was applied to one side. Then dry for 1 hour,
After being left at room temperature, this was used as a test piece.

Then, a 50 g / l solution of "A-screen A-220" (manufactured by Okuno Chemical Industries Co., Ltd.) was used for immersion for 5 minutes at 60 ° C. for degreasing. Subsequently, after washing with hot water at 60 ° C., CrO ₃ 400 g / l and H ₂ SO ₄ 200 ml / l
Etching treatment was performed at 65 ° C. for 8 minutes with the treatment liquid consisting of, and after the treatment, the resist ink layer was removed by washing with water at 25 ° C.

Then, the mixture was neutralized with 50 ml / l hydrochloric acid at 25 ° C. for 2 minutes, washed with water, and then treated with "Catalyst C" (manufactured by Okuno Chemical Industries Co., Ltd.) 40 ml / l and hydrochloric acid 50 ml / l. The catalyst was applied at 25 ° C. for 4 minutes.

After washing with water at 25 ° C., activation treatment was carried out with a solution of 100 ml / l of sulfuric acid and 1 g / l of sodium chloride at 50 ° C. for 5 minutes.

After further washing with water at 25 ° C., finally using “TMP Chemical Copper New 100” (manufactured by Okuno Chemical Industry Co., Ltd.),
Electroless copper plating was performed at 25 ° C for 12 minutes. As a result, it was possible to obtain a partial plating in which the plating film was not deposited on the resist ink applied portion.

Example 2 A resist ink having a water-soluble / water-insoluble transition temperature of 25 ° C.
The copolymer containing poly-N-isopropylacrylamide as the main component adjusted to
(× 10 cm × 0.3 cm) was applied on one side. Then, it was dried for 1 hour, left at room temperature, and used as a test piece.

Then, a 50 g / l solution of "A-screen A-220" (manufactured by Okuno Chemical Industries Co., Ltd.) was used to immerse the solution for 5 minutes at 60 ° C for degreasing. Subsequently, after washing with hot water at 60 ° C., CrO ₃ 400 g / l and H ₂ SO ₄ 200 ml / l
Etching treatment was performed at 65 ° C. for 8 minutes with a treatment liquid consisting of, and then washed at 30 ° C. with water.

Then, after neutralizing with 50 ml / l hydrochloric acid for 2 minutes at 25 ° C., the resist ink layer was removed at 20 ° C. by washing with water.

After the removal, a catalyst was applied for 4 minutes at 25 ° C. with a treating agent consisting of 40 ml / l of "Catalyst C" (manufactured by Okuno Chemical Industries Co., Ltd.) and 50 ml / l of hydrochloric acid.

After washing with water at 25 ° C., activation treatment was carried out with a solution of 50 ml / l of hydrochloric acid and 1 g / l of potassium chloride at 35 ° C. for 5 minutes.

After washing with water at 25 ° C., “TMP Chemical Copper New 1
00 "(manufactured by Okuno Chemical Industries Co., Ltd.)
Electroless copper plating was performed for a minute. As a result, it was possible to obtain a partial plating in which the plating film was not deposited on the resist ink applied portion.

Example 3 A resist ink having a water-soluble / water-insoluble transition temperature of 25 ° C.
The copolymer containing poly-N-t-butylacrylamide as the main component, which was prepared as described above, was used, and an ABS resin plate (10 cm × 10
cm x 0.3 cm) was applied to one side. Then, it was dried for 1 hour, left at room temperature, and used as a test piece.

Next, a 50 g / l solution of "A-screen A-220" (manufactured by Okuno Chemical Industries Co., Ltd.) was used for immersion for 5 minutes at 60 ° C. for degreasing. Then, after washing with water at 30 ° C., CrO ₃ 400 g / l and H ₂ SO ₄ 200 ml / l
Etching treatment was performed at 65 ° C. for 8 minutes with a treatment liquid consisting of, and then washed at 30 ° C. with water.

Then, it was neutralized with 50 ml / l hydrochloric acid at 25 ° C. for 2 minutes, washed with water at 25 ° C., and then "catalyst C".
(Okuno Pharmaceutical Co., Ltd.) 40 ml / l and hydrochloric acid 50 m
The catalyst application was carried out for 4 minutes at 25 ° C. with the treating agent consisting of 1 / l. Then, the resist ink layer was removed by washing with water at 20 ° C.

Subsequently, activation treatment was carried out with a solution of 50 g / l of sodium hydroxide and 1 g / l of sodium fluoride at 40 ° C. for 5 minutes.

After washing with water at 25 ° C., "TMP chemical nickel"
(Okuno Pharmaceutical Co., Ltd.) was used for electroless nickel plating at 40 ° C. for 8 minutes. As a result, it was possible to obtain a partial plating in which the plating film was not deposited on the resist ink applied portion.

Example 4 A resist ink having a water-soluble / water-insoluble transition temperature of 20 ° C.
The copolymer whose main component is poly-NN-dimethylacrylamide prepared in
(× 10 cm × 0.3 cm) was applied on one side. Then, it was dried for 1 hour, left at room temperature, and used as a test piece.

Next, a 50 g / l solution of "A-screen A-220" (manufactured by Okuno Chemical Industries Co., Ltd.) was used for immersion at 60 ° C. for 5 minutes for degreasing. Then, after washing with water at 30 ° C., CrO ₃ 400 g / l and H ₂ SO ₄ 200 ml / l
Etching treatment was performed at 65 ° C. for 8 minutes with a treatment liquid consisting of, and then washed at 30 ° C. with water.

Then, the mixture was neutralized with 50 ml / l hydrochloric acid at 25 ° C. for 2 minutes, washed with water, and then treated with "Catalyst C" (manufactured by Okuno Chemical Industries Co., Ltd.) 40 ml / l and hydrochloric acid 50 ml / l. The catalyst was applied at 25 ° C. for 4 minutes.

After washing with water at 25 ° C., 50% of 37% ammonia water
ml / l and ammonium fluoride 1g / l solution at 35 ° C
Was activated for 5 minutes. After that, the resist ink layer was removed by washing with water at 15 ° C.

Finally, "TMP chemical nickel" (manufactured by Okuno Chemical Industries Co., Ltd.) was used to perform electroless nickel plating at 40 ° C. for 8 minutes. As a result, it was possible to obtain a partial plating in which the plating film was not deposited on the resist ink applied portion.

Example 5 A resist ink having a water-soluble / water-insoluble transition temperature of 40 ° C.
The copolymer containing poly-N-hydroxyethylacrylamide as the main component, prepared as described in 1. above, was used and coated on one side of an ABS resin plate (10 cm × 10 cm × 0.3 cm). Then 1
After being dried for an hour and left at room temperature, this was used as a test piece.

Next, a 50 g / l solution of "A-screen A-220" (manufactured by Okuno Chemical Industries Co., Ltd.) was used for immersion for 5 minutes at 60 ° C. for degreasing. Subsequently, after washing with hot water at 60 ° C., CrO ₃ 400 g / l and H ₂ SO ₄ 200 ml / l
Etching treatment was performed at 65 ° C. for 8 minutes with the treatment liquid consisting of, and after the treatment, the resist ink layer was removed by washing with water at 25 ° C.

Then, the mixture was neutralized with 50 ml / l hydrochloric acid at 25 ° C. for 2 minutes, washed with water, and then treated with "Catalyst C" (Okuno Pharmaceutical Co., Ltd.) 40 ml / l and hydrochloric acid 50 ml / l. The catalyst was applied at 25 ° C. for 4 minutes.

After washing with water at 25 ° C., activation treatment was carried out with a solution of 100 ml / l of sulfuric acid and 1 g / l of sodium chloride at 50 ° C. for 5 minutes.

After further washing with water at 25 ° C., finally using “TMP Chemical Copper New 100” (manufactured by Okuno Chemical Industry Co., Ltd.),
Electroless copper plating was performed at 25 ° C for 12 minutes. As a result, it was possible to obtain a partial plating in which the plating film was not deposited on the resist ink applied portion.

Example 6 A resist ink having a water-soluble / water-insoluble transition temperature of 40 ° C.
The copolymer containing poly-N-methylacrylamide as the main component, which was adjusted to 1. As a sample, a glass epoxy laminated plate plated with copper by a semi-additive method was used.

First, the sample was filled with holes, and then the resist ink was used for patterning, and then "Top Etch" (manufactured by Okuno Chemical Industries Co., Ltd.) was used to perform alkali etching at 55 ° C. It was

Then, the sample was filled with holes, and at the same time, the resist ink layer was removed by washing with water. Further, it was dipped in solder resist and solder to perform terminal plating. As a result, a printed wiring board utilizing partial plating could be obtained.

Test Example 1 Degreasing and etching were carried out in the same manner as in Example 1 using an ABS resin, and palladium and tin were adsorbed in the subsequent catalyst application step, and a test piece was activated under each condition as shown in Table 1. After the chemical treatment, the amount of adsorption of palladium and tin after the treatment was measured. The results are shown in Table 1. In addition, 1 g / l of sodium chloride was used for the activation treatment as a halogenated compound.

[0050]

[Table 1]

From these results, it is understood that the effect of removing the catalyst is more excellent when the activation treatment is performed by adding the halogenated compound than when the halogenating compound is not added.

Claims (2)

[Claims] 1. In an electroless plating process, poly-N-methylacrylamide, poly-N-isopropylacrylamide, poly-Nt-butylacrylamide, poly-N-hydroxyethylacrylamide and poly A layer of a resist ink containing at least one selected from a temperature-sensitive polymer composed of -NN-dimethylacrylamide as a main component is formed in advance, the resist ink layer is removed after etching, and then electroless. A partial plating method characterized by performing a plating treatment. 2. The partial plating method according to claim 1, wherein a halogenated compound is added to the activation solution in the electroless plating step.