JPS63304692A - Manufacture of printed-wiring board - Google Patents

Abstract

PURPOSE:To simplify a process, to save a manhour, to cut down a raw material cost as well and to make low a manufacturing cost by a method wherein a bonding agent pattern part is formed on the surface of an insulating substrate, the substrate is covered with fine powder of solder to make the fine powder adhere to the pattern part and the solder fine powder is heated and fused to form a solder conductive circuit on the bonding agent pattern part. CONSTITUTION:An insulating substrate 1 is subjected to perforation processing, then when a circuit is printed, a thermosetting bonding agent 3 is used instead of printing ink and the bonding agent is ready-coated on the parts of holes 2 as well. Then, the substrate is covered with fine powder of solder 4, the excessive parts of the powder are blown off with the compressed air and the powder is adhered only to a printed circuit part. Then, the powder is heated in a nonoxidizing atmosphere to cure the bonding agent and to fuse the solder. In case a solder film is thin and the wire diameter of the circuit is fine, they are reinforced by dipping it in solder using a solder machine. Thereby, the substrate can be used for any if it can withstand a solder temperature, the raw material cost is low, a reduction in the cost of the substrate is possible as there is not such a wet treatment process as plating and the substrate becomes one having a competitive power in cost.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a printed wiring board. [Prior Art] Conventionally, this type of manufacturing method uses a copper-clad laminate,
The subtrack method involves etching all parts other than the circuit, the full additive method involves forming copper only on the circuit directly on the insulating laminate, and the subtrack tip method described above is used to form the circuit by removing the hole walls and lands. A partial additive method, which is created using the above-mentioned full additive method, is known.

[Problem that the invention seeks to solve]

All of the above-mentioned conventional manufacturing methods have nine problems: the steps are complicated and require a lot of man-hours, and many of the raw materials are of high quality, resulting in high manufacturing costs.

[Means for solving problems]

The uninvented printed wiring board manufacturing method includes a step of forming an entire adhesive pattern on the surface of an insulating base material, a step of sprinkling fine powder of solder on the base material and adhering it to the pattern part, and a step of dispersing the solder. The present invention is characterized in that it includes a step of heating and melting the solder powder to completely form a solder conductive circuit on the adhesive pattern portion.

〔Example〕

Next, the present invention will be explained with reference to all the drawings.

First, an insulating substrate 1 (for example,
Holes are drilled into the phenolic resin paper substrate), and then the circuit is printed. At this time, a thermosetting adhesive 3 is used instead of printing ink (FIG. 1(B)). Adhesive is also applied to the hole wall 2. Next, apply fine solder powder 4 (Figure 1 (C)) and blow off the excess with compressed air (
Figure 1 u)l). Fine solder powder adheres only to the printed circuit area. Next, it is heated in a non-oxidizing atmosphere to harden the adhesive and melt the solder (see Figure 1 (smell)).

If the cow skin is thin or the wire diameter of the circuit is small, V
C is reinforced by soldering with a solder machine (
Figure 1 (c).

〔Effect of the invention〕

As explained above, the inventiveness is that ■ Any insulating substrate can be used as long as it can withstand the soldering temperature (
(e.g. ceramics, general laminates, high temperature resistant resins, etc.).

■ Not only one side but also both sides are possible.

■ If you use pad printing, it can also be used on housings, etc.

■ Low raw material costs.

■ Cost reduction is possible because there is no wet processing process such as plating.

It is a highly cost-competitive manufacturing method with the following characteristics.

It is particularly suitable for manufacturing low-cost printed wiring boards for home appliances, keyboards, etc.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention. 1... Insulating substrate, 2... Hole, 3...
...Thermosetting adhesive.

Claims (1)

[Claims] forming an adhesive pattern on the surface of the insulating base material;
The method includes the steps of sprinkling fine solder powder on the base material and adhering it to the pattern portion, and heating and melting the fine solder powder to form a solder conductive circuit on the adhesive pattern portion. A method for manufacturing a printed wiring board.