JPS59207651A - Manufacture of filmy circuit substrate - Google Patents

Abstract

PURPOSE:To facilirate the manufature of an accurate filmy circuit, by depositing a film circuit material, and thereafter forming or shaping a filmy circuit pattern by the projection of a laser light beam. CONSTITUTION:A thick filmy conductor paste is printed on an insulating alumina substrate 1 and burned. Thus a thick conductor film 2 of silver palladium is formed. A thick filmy resistor paste is printed and burned and a thick film resistor 3 is formed. Unnecessary parts of the thick conductor film 2 and the thick film resistor 3 are burned away by a laser light beam, and a thick film conductor inductor 2' and a thick film resistor 3' are shaped.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a film circuit board, and particularly to a method for manufacturing a thick film circuit board.

A conventional method for manufacturing a thick film circuit board combines the steps of printing thick film conductor paste, thick film resistor paste, etc. on an insulating substrate, and firing each of the printed pastes.

However, the thick Iu film formed by this manufacturing method
When printing on an insulating substrate using a printing screen, the printing accuracy of each paste is poor because the screen is mesh-like and has a thickness of 25 to 50μ. Moreover, when the printed paste is fired, the paste spreads further due to the so-called "bleeding phenomenon", so the dimensional accuracy of the thick film circuit after firing is 50 to 10
It becomes 0μ.

Therefore, with this method, it was not possible to produce a fine pattern of 50 μm or less as a thick film circuit. One possible way to eliminate this drawback is to add a photoetching process using photoresist to the above-mentioned manufacturing process, but this increases costs due to restrictions on resist materials and etching solutions, and the addition of a complicated photoetching process. It's possible.

It is an object of the invention to provide a simple method for manufacturing precision membrane circuits.

Specifically, the method for manufacturing a film circuit board of the present invention includes shaping the entire desired portion of a film conductor or film resistor by irradiating it with a laser beam during the process of manufacturing the film circuit on an insulating substrate. The details of the special non-invention characterized in that it includes a step of forming the invention will be specifically explained by giving an example.

Figures 1(a) and 3(b) to 3(a) and (b) show each process diagram until the completion of the thick film circuit board according to the present invention, (a) is a surface view, and (b) is a cross-sectional view. Figures are shown respectively.

First, as shown in Fig. 1, a thick film conductor paste (mixed base of rose seam and silver) is applied on an alumina plate 1 which will become an insulating substrate.
19R Print the desired shape and sinter it in an electric furnace for firing to form the desired thick film conductor 2 of silver baladium on the alumina plate 1. After alignment, a thick film resistor paste (ruthenium oxide) is screen printed and fired in the same manner as the thick film conductor to form the desired thick film resistor 3. Next, the thick film conductor 2 of the thick film circuit shown in FIG. Unnecessary portions of the thick film resistor 3 are burned off by laser beam irradiation, and the thick film conductor inductor 2' and the thick film resistor 3 are shaped. In this case, it is also possible to shape the thick film resistor 3 and then laser trim the resistance value of the resistor. Generally, the width of the thick film conductor 20 at both ends of the thick film resistor 30 is generally wider than the width of the resistor 30. This aligns the thick film 24 body 2 and thick film resistor 3 (
This is to prevent both ends of the thick film resistor 3 from protruding from the thick film conductor due to misalignment when performing f-screen printing. In particular, resistor pattern misalignment has a more direct effect on circuit constants than conductor pattern misalignment, so the resistor must be made with greater precision. However, with such pattern design methods for thick film conductors and resistors, it is difficult to create dense layers and fine patterns for thick film circuits. In order to realize high-density, fine patterns for thick film circuits, it is necessary to match the width of the conductors at both ends of the resistor, eliminate unnecessary conductor width, and lay out the entire structure in a more dense manner. Not even '. Therefore, in the uninvented thick film substrate manufacturing method, the thick film conductors at both ends of the thick film resistor are printed in advance with a width equal to the design width required for the thick film #:vc body in FIG. In the screen printing of the resistor shown in Figure 2, the width of the resistor is printed and fired to be wide, contrary to the conventional method, so that the width of the resistor corresponds to the design width necessary for the resistor. This allows the misaligned portion to be burned off and shaped to the final design width of the resistor. Similarly, on the right side of the thick film conductor 2(1) in FIG. 2, unnecessary portions of the conductor are burned off by irradiation with a laser beam to form a fine conductive inductor circuit element.

In the description of the present invention, it has been described that the thick film conductor 2 and the thick film resistor 3 are shaped and pattern designed by irradiating each with a laser beam, but either the thick film conductor or the resistor is irradiated with a laser beam. It is clear that a method of shaping or forming the shape is also effective.

As explained above, according to the method for manufacturing a thick film circuit board of the present invention, a laser beam irradiation method is used as necessary to form a high-density, fine thick film circuit pattern. Correction of misalignment.

Improving dimensional accuracy, forming inductors, gears, capacitors, etc. may be difficult, and adding an extra complicated and expensive photo-etching process will reduce the resistance value correction that has traditionally been done. This is not possible simply by changing the program for the laser resistor trimming process. Therefore, it is possible to provide a method for manufacturing a fine thick film circuit board at low cost, with high yield, and with high positional accuracy, and its effects are significant.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, and FIG. 3 show process diagrams for explaining one embodiment of the method for manufacturing a thick film circuit board of the present invention.
) shows its surface view, and (b) shows its cross-sectional view. 1...Insulating alumina substrate, 2...Silver baladium thick film conductor, 2'...Thick film conductor inductor, 3...Ruthenium oxide thick film resistor body, 3
′・・・・・・Shaped thick film resistor. 6- 沁3珂(72) ri53 しd (shi)

Claims (1)

[Claims] 1. A method for manufacturing a film circuit board, which comprises, in the step of manufacturing a film circuit on an insulating substrate, forming or shaping a film circuit pattern by irradiating a laser beam after depositing a film circuit material.