JPS59129766A - Electroless plating method - Google Patents

Abstract

PURPOSE:To reduce the stage for forming a metallic pattern by forming only the desired pattern on a substrate with a resist of an alkali soluble type and performing simultaneously the stripping of the resist and the formation of a catalyst nucleus. CONSTITUTION:A substrate 1 having an insulating characteristic is formed thereon with a desired pattern exposing the substrate 1 only in the part where electroless plating is deposited by using a resist 2 of an alkali soluble type. The substrate is dipped in a catalyzer soln. to form a catalyst colloid complex ion 3 on the substrate 1 and the resist 2. The substrate is then dipped in an alkali soln. to change the ion 3 to a catalyst nucleus 4 and to dissolve away the resist 2 and the ion 3 at the same time. Electroless plating and a metallic film 5 are formed with the nucleus 4 adsorbed securely on the substrate 1 as a nucleus. The stage is thus reduced by a number of steps.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electroless plating method, and is intended to form a solid pattern on a substrate by aseptic and sanding without an etching process.

Taking the conventional metal pattern forming method as an example of a printed circuit board,
Explain including the shortcomings. The manufacturing process of Tourinto board is
A large number of steps must be performed, even if briefly described as adhesive application, copper foil pasting, hole cleaning, sensitizer dipping, activator dipping, through-hole menky resist pattern formation, etching, resist peeling, and final plating.

Requiring a large number of processes increases costs, delays in delivery,
This causes problems such as decreased yield and impeded rationalization.

The present invention is intended to eliminate these drawbacks,
Taking printed circuit boards as an example, it is possible to eliminate the use of copper foil, eliminate the adhesive coating process, copper foil pasting process, through-hole coating process, etching process, and resist stripping process, and replace it with electroless plating without the etching process. The purpose is to form a metal pattern on a substrate. The present invention will be explained in detail below with reference to the drawings.

1 to 5 are manufacturing process diagrams showing the present invention.

For the insulating substrate 1 as a raw material, any insulating material such as glass epoxy, polyimide, ABS, ceramic thread, glass thread, etc. can be used. Further, when using a conductive material such as a spiritual material, the manufacturing process of the present invention can be applied to coat the surface with an insulating material.

FIG. 2 is a cross-sectional view of an alkali-soluble type resist 2 formed on a substrate 1. As shown in FIG. In order to produce the effects of this manufacturing method, it is essential to use an alkali-soluble type resist. As a pattern forming method, conventional methods such as screen printing and photolithography can be applied as they are. In forming the pattern, care must be taken to expose the portion of the substrate 1 where the metal pattern is to be formed.

FIG. 3 is a cross-sectional view showing catalyst colloid complex ions 3 formed on the substrate 1 and resist 2 by immersion in a catalytic solution. It is desirable to use a one-component type of catalyst nucleation treatment solution for electroless plating as the catalyzer solution for catalyst nucleation and resist stripping, and the composition is P(1(! 12-0.2 ~
5g/1. ．． Snc 12-10~40g/t
, concentrated F['4 100 to 200 cc/l, the catalyst colloidal complex ions 3 can be formed as an invisible thin film on the surfaces of the substrate 1 and the resist 20 in a range of 10 seconds to 10 minutes at room temperature.

FIG. 4 is a diagram in which the catalyst colloid complex ions 3 are immersed in an alkaline solution to convert them into catalyst nuclei 4, and the catalyst colloid ions 3 on the resist 2 are removed at the same time as the alkali-soluble resist 2 is dissolved. Catalyst colloid complex ion 3
Since is hydrophilic, the alkaline solution easily reaches the resist 2 and dissolves it, and at the same time, the colloidal complex ions 3 on the resist 2 are also removed. In addition, the catalyst core colloidal complex ions 3 on the substrate change into catalyst nuclei 4 when they come into contact with an alkali, and are strongly adsorbed to the substrate 1, so that the catalyst nuclei 4 other than the resist area
remains after alkali treatment. The solution used for alkali treatment may be a chemical that shows alkalinity when dissolved, and NaoE (-10g/L to 100g/L, 1
The effects of the present invention can be obtained by treatment at 0 to 80°C for 1 to 10 minutes.

FIG. 5 shows a cross-sectional view of the α metal coating 5 formed by electroless coating using the catalyst core 4 as the core. By immersing the substrate shown in FIG. 4 in an electroless plating bath, electroless plating starts to be deposited using the catalyst nuclei 4 as the nuclei, and thereafter the deposited metal film 5 acts as a catalyst and the metal film 5 is formed. Continue to grow. Further, since no metal coating is grown in areas where catalyst nuclei 4 are not formed, selective plating or pattern plating in which metal coating 5 is formed only in desired areas is possible. Any metal bath can be used as the electroless plating bath as long as it is an autocatalytic type bath.

As described in detail above, by using the method according to the present invention, it is possible to form a @ group p-y on a substrate without an etching step. Furthermore, since resist stripping and catalyst nucleation are performed simultaneously, a great effect can be obtained in shortening the process.

The manufacturing process when using the electroless plating method of the present invention for a printed circuit board is as follows: stripping, cleaning, resist pattern formation, catalytic treatment, alkali treatment, electroless menky finish plating, through-hole metal plating, and metal pattern formation at the same time. 9, and the number of steps has been reduced from 11 in the conventional method to 7.
It is possible to significantly shorten the process.Shortening the process can greatly contribute to rationalization and cost reduction.

As for other uses, it can be applied to anything that forms a metal pattern on a substrate, and can be used for a wide range of purposes, such as hard masks for 7-office applications, patterning on glassware, and plating for improving the functionality of liquid crystal panels. I can do it.

Finally, to restate the characteristics of the electroless plating method according to the present invention, it is possible to form a metal pattern on the substrate without an etching process, resulting in a significant cost reduction. IAiL
This technology enables pattern plating of fine lines within the range allowed by the resolution of photoresist, and is an indispensable technology for the development of future electronic technology.

[Brief explanation of drawings]

1 to 5 of the drawings are cross-sectional views showing one process of the present invention. FIG. 1 is a diagram showing a substrate that provides insulation. Figure 2 is a diagram of Bakun formation by the resist, Figure 15 is a diagram showing the catalyst colloid complex ion adhesion by the catalytic liquid. A diagram showing pattern plating with an electroless plating film deposited on top. 1...Substrate, 2...Resist, 5...Catalyst colloid complex ion. 4... Catalyst nucleus, 5... Metal coating. Applicant Suwa Seikodai Co., Ltd. Agent Patent Attorney Mogami Tsumu 2 2 2 2 4

Claims (1)

[Claims] (1) Form a desired pattern on an insulating substrate with an alkali-soluble resist, exposing only the part where the electroless coating is to be deposited, and adsorb catalyst colloid complex ions on the entire surface by immersion in a catalyzer. . Next, the catalyst colloid complex ions are converted into form nuclei by immersion in an alkaline solution, and at the same time, the alkali-soluble resist and the hornworm colloid complex ions on the alkali-soluble resist are simultaneously dissolved and removed, and the catalyst colloid of the substrate is removed. An electroless plating method characterized by depositing deplated metal only on the areas where the nuclei are adsorbed.