JPS5826199B2 - Manufacturing method of printed wiring board with metal core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a printed wiring board with a metal core. Specifically, the present invention relates to a method for manufacturing a printed wiring board with a metal core. The present invention relates to a method for cutting into final product shapes.

As the density of electronic devices increases, the physical requirements for printed wiring boards, such as heat dissipation ability and rigidity that can withstand the mounting of a large number of heavy components, are increasing. Printed wiring boards made of metal materials are not fully satisfactory, so there is a trend towards printed wiring boards based on metal materials.

Metal-core printed wiring boards use a metal-core substrate whose surface is insulated, but generally, this metal-core substrate is either an insulated one with a work handle added to the final product external shape, or a final product. It is a piece that is slightly larger than the original shape and has been insulated.

After forming a conductive circuit on this metal core board by printing wiring processing, the metal core board is shaped into a final product by cutting the handle for external processing or working, and insulating the cut portion to complete a metal core printed wiring board.

When cutting this external shape or working handle to make the metal core board into the final product shape, when cutting with normal mold punching or shearing, burrs are generated at the cut part as shown in Figure 1, and the finishing process is to remove burrs with a file. In addition, dust and foreign matter from the deburring work adhere to the printed wiring board, causing problems both industrially and in terms of quality.

In FIG. 1, 1 is a board in the shape of a final product, 2 is a handle for working, and 3 is a handle.

The present invention has been made in view of these points, and involves printing wiring or cutting work handles on a metal core substrate whose surface has been insulated, shaping the metal core substrate into a final product shape, and insulating the cut portion. In the manufacturing method of printed wiring boards, when processing the external shape or cutting the work handle, a groove is cut in the cut part, and the die is cut by punching from the opposite side of the groove at the groove part. Since it does not protrude from the board, there is no need to perform deburring work, thereby preventing dust from adhering.

FIG. 2 shows the case of cutting by the method of the present invention, and 4 indicates the groove.

The present invention will be specifically illustrated by examples.

Example: A through hole with a diameter of 16 mm was punched at a predetermined location on an iron plate with a thickness of 1.2 mm using an NC turret punch press, and a working handle was left in the final product size.

Epoxy resin is formed with a thickness of 150μ by electrodeposition coating,
Furthermore, a sensitizer-containing adhesive HA-0,4 (trade name, Hitachi Chemical Co., Ltd.) was applied to a thickness of 40 μm.

Panel copper plating was formed by chemical copper plating of 5 μm on the entire surface and further electroplating of 20 μm of copper.

A resist for pattern plating was formed, and pattern electrolytic copper plating and solder plating were performed to form circuits and plugs.

After pattern plating, the pattern plating resistor was removed using a methylene chloride remover, and unnecessary panel copper was etched using ammonium persulfate or the like.

Next, use a die to punch a groove in the cutting part of the work handle, and then use a die to cut from the groove part using a die from the opposite side of the groove, then apply epoxy resin to the cut section with a brush. As a result of coating, it was confirmed that the cut part did not protrude beyond the thickness of the product board, and even after the epoxy resin was applied with a brush, it was sufficiently insulated and beautiful.

As explained above, in conventional external processing or cutting of handles for work, the burr protrudes from the plate thickness, requiring burr removal work, and furthermore, this dust adheres to the product, causing defects and also problems in terms of work man-hours. However, according to the present invention, the cutting edge does not fly off beyond the board thickness, and furthermore, since there is no need to remove the edge, there is no adhesion of dust, and the same can be achieved in terms of man-hours and quality. done.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the cutting part of the working handle in the conventional method,
The figure is a sectional view of a cut portion of the working handle according to the present invention. Explanation of symbols, 1... Board in final product shape, 2.
...Work handle, 3... Paris, 4...
...■ Groove.

Claims (1)

[Claims] 1 After forming a conductive circuit on a metal core substrate whose surface has been insulated, the metal core substrate is shaped into a final product by external processing or cutting of a working handle that connects to the external shape, and the cutting area is insulated. In the manufacturing method of wiring boards, a notch is formed in a metal core substrate that has been insulated, and the groove portion is punched and cut from the opposite side to form the final product shape of the metal core substrate. A method for manufacturing a printed wiring board with a metal core, characterized by: