JPS6031116B2 - Electric wiring circuit board and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical wiring circuit board and a method for manufacturing the same, and more particularly to an electrical wiring circuit board in which the material of the electrical wiring circuit is improved and a method for manufacturing the same.

Accordingly, etching methods and photoetching methods are known as methods for forming a desired electrical wiring circuit on an insulating substrate. FIG. 1 is a diagram schematically showing a manufacturing process for forming an electrical wiring circuit or circuit pattern by a conventional etching method.

In the figure, when forming an electric wiring circuit by the etching method, first a layer of copper foil is applied to the surface in the first step.
An insulating substrate 2 such as a laminate or a laminate film having a laminate formed thereon is prepared, or a copper foil 1 is pasted on the insulating substrate. In the second step, the copper foil 1
An etching resist 3 is printed on top to form a desired electrical wiring circuit. In the third step, the insulating substrate on which the etching resist 3 is printed is immersed in a ferric chloride solution to remove unnecessary copper foil from areas other than desired electrical wiring circuit parts. Thereafter, in a fourth step, the etching resist 3 is peeled off to obtain a desired electrical wiring circuit. Then, if necessary, in a fifth step, gold plating 4 is applied to the surface of the copper foil 1 that will form the desired electrical wiring circuit for the purpose of preventing oxidation of the copper foil. Note that the copper foil 1 may be protected by carbon printing instead of gold plating. However, the method of manufacturing electrical wiring circuits using the etching process shown in FIG. 1 requires printing of an etching resist, etching process, peeling off the resist, and anti-oxidation process, resulting in a large number of process steps. This method requires a step of removing the copper foil by immersing it in a ferric chloride solution, which requires a long processing time, and there is a problem in that a large amount of etching cannot be carried out quickly and in a short period of time.

Further, electric wiring circuit boards manufactured by the etching process cannot be mass-produced due to the complexity of the etching process and are expensive because the surface of the copper foil is plated with a precious metal. Therefore, an object of the present invention is to provide an electrical wiring circuit board that can be manufactured at low cost without using precious metals and is suitable for mass production.

Another object of the present invention is to manufacture an electrical wiring circuit board that can simplify the manufacturing process, shorten the processing time, and eliminate the need for processes such as printing etching resist, etching, and peeling off the resist film. The purpose is to provide a method. In summary, this invention involves making base metal powder into a paste form using an adhesive, forming a desired circuit pattern on an insulating substrate using the base metal paste, attaching an antioxidant material powder to the base metal paste, and curing the base metal paste with heat. This is an electrical wiring circuit board manufactured by and a method for manufacturing the same.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a diagram schematically showing the steps of an electric wiring circuit board and a method for manufacturing the same according to an embodiment of the present invention.

Next, a method for manufacturing an electrical wiring circuit board according to the present invention will be explained with reference to FIG. In the first step, an insulating substrate 2 and a base metal paste 5 are prepared. Here, as the insulating substrate 2, various substrates such as a laminate plate, a glass plate, or an insulating film can be used as long as the adhesive strength between the insulating substrate 2 and the base metal paste 5 is sufficient. The base metal paste 5 is made by pasting conductive base metal powder with an adhesive. Base metal here refers to precious metals, and refers to metals that are easily oxidized in the air. Copper, nickel, aluminum, or the like is used as the base metal. Base metal powder such as copper is then mixed with a polymer adhesive or the like to create a base metal paste (or knot paste). In the second step, a desired electrical wiring circuit is formed on the insulating substrate 2 using the base metal paste 5 using a screen printing method. In the third step, the surface on which the base metal base 5 was printed in the above-mentioned second step and the insulating substrate 2 on which the base metal paste 5 is not printed, if necessary.
Antioxidant material powder 6 is sprinkled on the upper surface of.

Here, as the antioxidant material powder 6, graphite powder, carbon powder, or the like is used. In this way, the printed base metal paste 5 to form the desired electrical wiring circuit is coated with an antioxidant material powder 6 such as graphite powder or carbon powder. At this time, since the base metal paste 5 contains an adhesive, the antioxidant material powder 6 is
However, it remains on the isolated diamond substrate 2 without adhering to it. Thereafter, in a fourth step, the insulating substrate 2 on which the base metal paste 5 was coated with the antioxidant material powder 5 in the third step is heated with heat 7, and as a result, the base metal paste 5 is heated and hardened. be done.

By heating and curing in this manner, the base metal paste 5 remains on the insulating substrate 2 in a state covered with the antioxidant material powder 6, but the antioxidant material powder 6 in the portion where the base metal base 5 is not formed is It is removed without adhering to the insulating substrate 2. The electrical wiring circuit board manufactured in this manner is shown at the bottom of FIG. 2.

That is, in the electric wiring circuit board manufactured by the manufacturing method of the present invention, a desired electric wiring circuit is formed on an insulating substrate 2 using a base metal paste 5, an antioxidant material powder is adhered on the base metal paste 5, and the base metal paste 5 is thermally cured. By the way, depending on the electrical wiring circuit board, some circuit parts may require soldering.

Therefore, when manufacturing an electrical wiring circuit board with circuit parts that require soldering, it is sufficient to manufacture them as shown in FIG. 3. That is, after performing the second step shown in FIG. 2, the anti-oxidant material powder 6 is partially sprayed on the part 8 that requires soldering using a mask, etc., and the anti-oxidant material powder is applied only to the other parts. 6 may be sprayed and then heated and cured. In this way, after heating and curing, by removing the mask, the base metal paste 5 remains exposed in the portion 8 that requires soldering, and it becomes possible to perform soldering directly. As described above, according to the present invention, the following unique effects are achieved.

Printing of etching resist, etching process, peeling of resist film, and anti-oxidation measures are no longer required, which simplifies the processing process, reduces processing time for each process, facilitates mass production, and significantly reduces costs. can be achieved.

(b) Since the base metal powder of the base metal paste is covered with anti-oxidation material powder and shielded from the atmosphere, it is possible to prevent a decrease in conductivity due to oxidation of the base metal powder and improve the reliability of contact continuity.

C. Various types of insulating substrates can be used as long as the adhesive strength between the insulating substrate and the base metal paste is sufficient, and in particular, when an insulating film is used, it is highly flexible and can be used by being bent.

D. Since anti-oxidation treatment can be performed without using precious metals, the manufacturing cost of one electrical wiring circuit board is reduced. E) Since the base metal paste oxidizes the circuit surface after curing, it could not be used for circuits or contacts that require continuity through contact, such as keyswitches. Therefore, the scope of use of base metal paste can be greatly expanded.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram schematically showing a method for manufacturing an insulating substrate using a conventional etching method. FIG. 2 is a diagram schematically showing an insulating substrate according to an embodiment of the present invention and a method for manufacturing the same. FIG. 3 is a diagram schematically showing a manufacturing method of another embodiment of the present invention. In the figure, 1 is a copper foil, 2 is an insulating substrate, 3 is an etching resist, 4 is gold plating, 5 is a base metal paste, 6 is an antioxidant material powder, 7 is heat, and 8 is a circuit portion that requires soldering. Ticket 1 Diagram ヱ Oni Hayabusa 1 Z Yomo Z Boss Hatake 3 S Hatake 4 Ehaku 3 Ren Otsu Zu/Kaneboshi 1 Engineering Work 2 Toyo 3.4 Figure 3

Claims (1)

[Scope of Claims] 1. An insulating substrate, a base metal paste in which conductive base metal powder is made into a paste with an adhesive and formed on the insulating substrate to form a desired electrical wiring circuit, and a base metal paste on the base metal paste. An electrical wiring circuit board having an antioxidant material powder that prevents oxidation of a deposited and thermoset base metal paste. 2. The electrical wiring circuit board according to claim 1, wherein the base metal paste is made of copper powder made into a paste with a polymer adhesive. 3. The electrical wiring circuit board according to claim 1, wherein the antioxidant material powder is carbon powder. 4. The electrical wiring circuit board according to claim 1, wherein the antioxidant material powder is graphite powder. 5. A method for forming a desired electrical wiring circuit on an insulating substrate, the step of preparing a base metal paste made of conductive base metal powder with an adhesive, and forming the insulation with the base metal paste by screen printing. forming a desired electrical wiring circuit on a substrate, at least the step of sprinkling an antioxidant material powder on the printed base metal paste, and the insulation with the antioxidant material powder sprinkled on the base metal paste. A method for manufacturing an electrical wiring circuit board, which comprises manufacturing the electrical wiring circuit board by heating the board and thermosetting the base metal paste.