JPS6211291A - Manufacture of circuit board - 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] [Technical field of invention] The present invention relates to a method of manufacturing a circuit board.

[Technical background of the invention and its problems]

Conventionally, when manufacturing circuit boards, etching resist is screen printed on the metal layer on the insulating plate.

Alternatively, a predetermined resist pattern is obtained by photolithography using a photosensitive etching resist, and the exposed metal layer is dissolved with an etching solution to obtain a single circuit pattern. When using these methods, a photographic mask was always required as the original image. For this reason.

Because of the time required for mask production, there were inconveniences such as not being able to meet short delivery deadlines, and defective products being manufactured because the masks were easily damaged. Provided is a method for manufacturing a circuit board that overcomes problems in forming the circuit board by technology.

[Summary of the invention]

In the present invention, 8 gold layers are formed on one or both sides of an insulating plate, and on this metal layer, an etching resist layer made of a polymer compound that easily absorbs light, denatures, and does not easily leave a residue is formed. The irradiation area of the resist 1 is scanned in a predetermined pattern with a laser beam controlled by a computer to volatilize the resist layer, the exposed metal layer is etched, and the remaining resist layer is peeled off to form a predetermined pattern. This is a method of manufacturing a circuit board in which a pattern is formed.

Here, as an etching resist made of a polymer compound that easily absorbs light, denatures, and does not easily leave a residue,
Polyethylene resin, polypropylene resin, acrylic resin, nitrocellulose.

Ethyl cellulose, carboxymethyl cellulose.

Examples include polyvinyl butyl wool resin. Acrylic resins are particularly suitable, and various acrylic copolymers can be used. On the other hand, additives for absorbing light must be selected depending on the wavelength of the laser light to be used.

For example, Rhodamine B, Desperfast Pink R9, etc. are suitable for the wavelength of 487 nm of the argon laser, and oil black, diamond black, etc. are suitable for the wavelength of 11060 nm of the Nd;YAG laser. The etching resist is prepared by selecting dyes and pigments depending on the laser used and dispersing them in the polymer compound.

〔Effect of the invention〕

(1) There is no need to create an original mask for pattern formation; the distribution layout can be drawn on a computer, and a predetermined pattern can be directly formed on the etching resist using this data.

The delivery time can be shortened, and circuit boards can be manufactured economically in small quantities.

[Embodiment 1 of the Invention] An embodiment of the present invention will be described with reference to the drawings. 1.6mm thick phenolic resin copper clad laminate (product name: Nitrite CCL)
-8A73 (manufacturer Mitsubishi Gas Chemical KK) is covered with 35μ steel foil. This was cut into 100 square pieces. Separately, as an etching resist, polymethyl methacrylate resin was dissolved in N,N-dimethylformamide to a concentration of 10% and 1%, and 2 tons of oil black was added to 100 parts by weight of this solution to uniformly disperse and dissolve. Ta. This was uniformly applied onto the steel layer 2 of the steel clad laminate 1 using a spinner to obtain an etch resist layer 3. The dry thickness was approximately 5 μm. Next, a Na:YAG L/- laser device (trade name LAY-7) with a wavelength of 1.06 μm was used.
11 (using Toshiba I!ri, beam spot diameter 50μ, bite size 2μ, Q switch, chi frequency 2000Hz,
Average laser beam output 5W, spot moving speed 40mm/
See and remember. 4 in the figure is a laser beam irradiation part.

As shown in the figure, draw 500 straight lines with a pitch of 100 μm and a length of 50 mm, and then irradiate the fc local area.
I made it so that each line has an independent pattern. This drawing was automatically drawn using a computer built into the laser device.

The copper foil surface is exposed to the laser beam without any damage! 7. This was etched in a ferric chloride water bath for 5 minutes. Thereafter, the etching resist layer was removed using trichlorethylene. As a result of observing this with a microscope, the conductor width was 55 μm.
A clean pattern was formed with an insulating part of 45 μm, and there were no short circuits in all cases when electrically checked.

[Brief explanation of drawings]

The drawings are diagrams for explaining one embodiment of the present invention. 1... Copper-clad laminate, 2... Steel layer, 3... Resist layer. 4... Laser light irradiation part. Agent Patent Attorney Ken Nori Chika Udo Kikuo Takehana

Claims (1)

[Claims] a step of forming a metal layer with a uniform thickness on the entire surface of the insulating layer;
A process of forming an etching resist layer made of a polymer compound that easily absorbs light, denatures, and does not leave residue on this metal layer, and a laser beam controlled by a computer is scanned in a predetermined pattern to volatilize the resist layer. 1. A method for manufacturing a circuit board, comprising: a step of etching an exposed metal layer; and a step of peeling off a resist layer.