JP2643450B2 - Method of forming through-hole conductor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a through-hole conductor on a thick-film integrated circuit board.

2. Description of the Related Art Generally, to form through holes in a thick film integrated circuit board, conventionally, as shown in the process diagram of FIG. The thick film conductor paste is printed using a screen printer while adsorbing, and the thick film conductor paste is attached to the inner wall of the through-hole.

The circuit pattern printed from the surface and the thick-film conductor paste in the through-holes are dried in an atmosphere at a temperature of 130 ° C. to 150 ° C. for about 10 minutes.

Using a screen printer to print a thick film conductor paste while vacuum-sucking from the lower part of the insulating base material in the same way from the back side, and apply a thickness so as to overlap the through-hole conductor formed from the front surface on the inner wall of the through-hole hole. The film conductor paste is applied.

The circuit pattern printed from the back side and the thick film conductor paste in the through-hole are dried in an atmosphere at a temperature of 130 ° C. to 150 ° C. for about 10 minutes.

In a thick film incinerator, the thick film conductor paste is sintered at a predetermined temperature profile to form electrically conductive through holes.

Undergoing the process.

FIG. 4 is a cross-sectional view of a conventional through-hole portion.
Is an insulating substrate, 2 is a thick film conductor, and 3 is a through-hole.

However, in the conventional through-hole conductor forming method as described above, the thickness of the thick-film conductor paste adhered to the inner wall of the through-hole increases, and at the same time, the printed portion from the front surface and the printing from the back surface. Due to the large step at the overlapping part of the formation part, cracks occur inside the through-hole holes during sintering of the through-hole conductor paste and the heat history and thermal shock test of the subsequent process, etc. There was a disadvantage that an open accident occurred.

The present invention has been made in view of the above circumstances, and has as its object to provide a highly reliable formation of a through-hole conductor by a simple method.

Means for Solving the Problems A method of forming a through-hole conductor according to the present invention is a method for forming a circuit pattern from a front side and a back side on a thick-film integrated circuit substrate having a thick-film circuit conductor on both sides of an insulating base material and through-holes for electrical connection between the front and back. And the thick-film conductor paste in the through-hole holes printed separately or simultaneously is dried simultaneously on the front and back.

Therefore, according to the present invention, the thickness of the thick film conductor paste adhered to the inner wall of the through-hole can be formed thin, and the step of the overlap between the print forming portion from the front surface and the print forming portion from the back surface is eliminated, so that a highly reliable through-hole can be obtained. A hole conductor is formed.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a process chart of a method of forming a through-hole conductor according to one embodiment of the present invention. Hereinafter, the steps of the embodiment will be described with reference to the drawings. First, a thick film conductor paste is printed using a screen printer while the vacuum is sucked from the lower part of the insulation substrate at the same time as the circuit pattern on the surface of the insulation substrate, and the thick film conductor paste is attached to the inner wall of the through-hole. .

Using a screen printer to print a thick film conductor paste while vacuum-sucking from the lower part of the insulating base material in the same way from the back side, and apply a thickness so as to overlap the through-hole conductor formed from the front surface on the inner wall of the through-hole hole. The film conductor paste is applied.

The circuit pattern printed from the front and back and the thick film conductor paste in the through-hole are dried in an atmosphere at a temperature of 130 ° C. to 150 ° C. for about 10 minutes.

In a thick film incinerator, the thick film conductor paste is sintered at a predetermined temperature profile to form electrically conductive through holes.

In this embodiment, through holes are formed in an insulating substrate through the above steps. FIG. 2 is a cross-sectional view of a through hole portion in one embodiment, wherein 1 is an insulating base material, 2 is a thick film conductor, and 3 is a through hole hole.

As described above, according to the present embodiment, the thick film conductor paste in the through hole hole printed and formed at the same time as the circuit pattern from the front and back sides of the thick film integrated circuit board is simultaneously dried on the front and back sides to adhere to the inner wall of the through hole. In addition to reducing the thickness of the thick film conductor paste to be made, there is no step between the print formation part from the front side and the overlap part of the print formation part from the back side, realizing a highly reliable through-hole conductor without cracks can do.

Effect of the Invention As is clear from the above description, the present invention provides a through-hole structure by simultaneously drying the thick-film conductor paste in the through-hole holes formed individually or simultaneously with the circuit pattern from the front and back of the thick-film integrated circuit board. The thickness of the thick film conductor paste attached to the inner wall of the hole can be reduced, and the step of the overlap between the print forming part from the front side and the print forming part from the back side is eliminated, and a highly reliable through-hole conductor without cracks is generated. An excellent effect that formation can be realized is obtained.

[Brief description of the drawings]

1 and 2 are process diagrams of a method of forming a through-hole conductor and a cross-sectional view of a through-hole portion in one embodiment of the present invention, and FIGS. 3 and 4 are process diagrams of a conventional method of forming a through-hole conductor. It is sectional drawing of a through-hole part. 1 ... insulating base material, 2 ... thick film conductor, 3 ... through-hole hole.

Claims (1)

(57) [Claims] 1. A method of forming a through-hole conductor for electrically connecting a thick-film circuit conductor to both sides of an insulating base material, the method comprising the steps of: a) simultaneously or separately from a surface of the insulating base material with a circuit pattern; A step of printing and forming a thick film conductor paste on the inner wall, and b) simultaneously or separately with the circuit pattern from the back surface of the insulating base material so as to overlap with the thick film conductor paste formed on the inner wall of the through hole by suction. A step of printing and forming a thick film conductor paste on the inner wall of the through hole by printing and suction; and c) a step of simultaneously drying the thick film conductor paste on the inner wall of the through hole hole printed and formed from the front and back sides. Conductor formation method.