JPS59106190A - Method of producing electronic 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 The present invention relates to a method for manufacturing an electronic circuit board, and in particular to an improvement in a method for forming fine conductor patterns on the corners of the board.

In liquid crystal display devices, hybrid integrated circuit devices, and the like, there is a strong desire to form conductive patterns at high density on the end faces of insulating substrates due to the requirement for high-density packaging. A conventional method of manufacturing an electronic circuit board used for this type of application will be explained with reference to the drawings. FIG. 1 is a perspective view showing an electronic circuit board formed by a conventional method. In the figure, (1) is an insulating substrate made of a material such as glass or ceramic, (1a) is the corner of the main surface and end surface of the substrate (1), and (2) is the first conductor pattern. The second conductor pattern (3) is formed on the main surface of the conductor pattern using a method such as screen printing using a conductive paste made of materials such as silver, copper, or silver-palladium. Using the same kind of material, for example, with the end surface of the substrate (1) facing up, transfer technology,
It is formed on the end surface of the substrate (1) by a method such as screen printing technology. (8a) is an overlapping conductor, which is a part of the second conductor pattern (3), and is caused by dripping of the conductive paste when forming the second conductor pattern (3).
The substrate ( 1
) is formed on a part of the main surface of the

Thereafter, the second conductor pattern (3) is cured or fired under predetermined conditions and adhered to the substrate (1). Electrical connection between the first conductor pattern (2) and the second conductor pattern (3) is made by the overlapping conductor (8a) portion of the second conductor pattern (3). In such a conventional method, the overlapping conductor (8a) connects the first conductor pattern (2) by utilizing the dripping of the conductive paste when forming the second conductor pattern (3).
), the dimensional accuracy of the overlapping conductor (8a) and the reliability of the connection with the first conductor pattern 2) were poor, and it was particularly difficult to form a conductor pattern with a pitch of 1 mm or less. In addition, although it is possible to form fine patterns on a flat surface using methods such as screen printing, when this method is used on corners, lifting will inevitably occur between the screen and the substrate (1). It was difficult to form fine patterns on the corners. Furthermore, in the conventional method, the substrate (
There was also a drawback that the second conductor pattern (3) was easily disconnected at the corner (1a) of (1), and reliability and productivity were poor.

This invention was made in order to eliminate the drawbacks of the conventional method as described above.A conductive paste is applied to the corners of an insulating substrate, and then the conductive paste is shaped into a predetermined shape using a laser beam. By hardening or firing the paste, and then removing the unhardened or unfired conductive paste to form a second conductive pattern, it is possible to overcome the limitations of fine patterns produced by conventional transfer techniques, especially V (difficult to manufacture corners). The purpose of this method is to form more precise micropatterns, especially at the corners.

The invention will now be explained with reference to the drawings. FIG. 2 is a perspective view of an electronic circuit board used to implement an embodiment of the present invention, and FIG. 8 is a perspective view of an m-child circuit board formed in an embodiment of the invention. (1a) is an insulating substrate (
1) The corner between the main surface and the end surface is processed into a curved surface by a method such as polishing. ) is a conductive paste,
Using the same type of material as the first conductor pattern (2), the end surface of the substrate (1) and the main part of the substrate 4 which is continuous with this and connects to the first conductor pattern (2) are formed using a method such as a transfer technique. It is formed on a part of the surface. C80a) is an overlapping coating. (4) uses a laser beam to coat the conductive paste, and then YAG (Yttrium Alum
A predetermined part of this conductive paste member is irradiated with a Garne J laser or the like to harden or bake the conductive paste in that part, and then the conductive paste is washed with ethanol, trichlorethylene, etc. Laser light (4) out of the conductive paste
The uncured or unfired portions that have not been irradiated are washed off to form a second conductor pattern (3). Electrical connection between the first conductor pattern (2) and the second conductor pattern (3) is made by the overlapping conductor (8a) as in the conventional case. Note that if the insulating substrate (1) is heated after forming the second conductor pattern (3), the second conductor pattern (3) and the substrate (
1) It is possible to improve the adhesion with 1). The second conductor pattern (3) thus formed has good dimensional accuracy and can form a precise fine pattern.

In addition, in the above embodiment, the second conductor pattern (3) was formed using the same kind of material as the first conductor pattern (2).
A different charge may also be used.

Furthermore, in the above embodiment, the corner (1a) between the end surface and the main surface of the substrate (1) is curved, but the substrate (1) which does not have a curved shape (
Of course, for 1), a fine pattern can also be formed by a similar method.

As described above, according to the present invention, after applying a conductive paste to the corners of a substrate, the conductive paste is cured or fired into a predetermined shape with a laser beam, and then the uncured or unfired conductive paste is Since the second conductor pattern is formed by removing the second conductor pattern, a more precise fine pattern can be formed, and there is an effect that formation can be easily performed especially at corners.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an electronic circuit board formed by a conventional method, FIG. 2 is a perspective view of an electronic circuit board used to implement an embodiment of the present invention, and FIG. FIG. 2 is a perspective view of an electronic circuit board formed in one embodiment. In the figure, (1) is an insulating substrate, (1a) is a corner of the main surface and end surface of the insulating substrate, (2) is a first conductor pattern, (
3) is the second conductor pattern, 2) is the conductive paste, and (4) is the conductive paste.
) is laser light. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Figure 1 Figure 2 Figure 3 =431-

Claims (2)

[Claims] (1) A step of forming a first conductor pattern on the main surface of the insulating substrate;
A step of applying a conductive paste to a part of the main surface of the insulating substrate so as to be connected to the conductor pattern, a step of curing or baking the conductive paste into a predetermined shape using a laser beam, a step of uncured or A method for manufacturing an electronic circuit board, comprising the step of removing the unfired conductive paste to form a second conductor pattern connected to the first conductor pattern. (2) A method for manufacturing an electronic circuit board according to claim 1, characterized in that the corners of the main surface and end surfaces of the insulating substrate are curved.