JPS6233353Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is used to manufacture printed circuits using the die stamping method. This relates to a die that can be simultaneously engraved with a symbol (e.g., "etc.").

(Prior art) Printed circuits using the die stamping method, for example, place a resin insulating substrate on a metal stand, and then place a metal foil with an adhesive layer on one side on top of the substrate. Place the die so that they face each other, and then punch down a die with a sharp edge according to the circuit pattern to be punched out from above, heat and press it onto the insulating substrate, and punch out the circuit conductor while adhering it. After the metal foil is removed, a conductive metal foil punched onto an insulating substrate is then bonded using a hot press.

FIG. 10 shows a part of the cross section of a die 20 used in the conventional die stamping method. It is formed by two sharp blades 21. That is, the portion of the metal foil 7 surrounded by the blade 21 formed on the die forms the circuit conductor, and the other portions of the metal foil are removed after stamping.

Characters, etc. are often engraved on the conductor parts of printed circuits made by the die stamping method, taking into consideration the convenience of incorporating the circuit board into equipment such as meters, wiring, and connections. In such cases, it is necessary to carry out a separate process of printing by pressing a die in which characters or the like to be engraved are engraved on the conductor portion.

(Purpose of the invention) The present invention has been made in view of the above-mentioned current situation, and it is an object of the present invention to provide a die capable of stamping characters, etc., on a circuit conductor portion at the same time as punching out the circuit conductor.

(Structure of the idea) The die of the present invention will be explained based on the drawings.

FIG. 1 is a plan view of the die 3 of the present invention, and the second
The figure is a sectional view of the section AA shown in FIG. 1. In Figures 1 and 2, 1 is a blade that punches out the outline of the circuit conductor, the part surrounded by this blade 1 is the part that forms the conductor part of the printed circuit, and 2 is the part that is stamped on the conductor part. This is the part where characters such as digits are printed, and in the present invention, this part will be referred to as a tooth to distinguish it from a blade.

As shown in FIG. 2, the cross-sectional shape of the blade 1 has a sharp angle at its tip. This angle is usually 20
~60 degrees; if the angle is more acute than this, the mechanical strength will be weak, and if the angle is obtuse, a large shearing load will be required, which is not preferable.

The cross-sectional shape of the tooth 2 is different from the blade 1 which cuts metal foil for forming a conductor, in that the tip part is flat with respect to the stamp surface, and the peripheral part is rounded. . If the periphery is not curved but has an acute angle, letters etc. will be engraved due to the shearing effect during stamping, but the metal foil may break.

The tip of blade 1 and the tip of tooth 2 have almost the same stamp surface, but even if the tip of tooth 2 protrudes beyond the tip of blade 1, the tip of tooth 2 is flat, so the metal foil It does not break and there is no particular inconvenience. A heat-resistant sheet material 4 such as a fluoroethylene sheet is bonded to the inner surface of the portion surrounded by the blade 1 as a filler. Due to the presence of this heat-resistant sheet material 4, when the die 3 is pressed, the conductor forming part is shallow, so it helps to suppress the metal foil by pressing, and the metal foil is not pressed in other parts. Even if there is an adhesive layer, there is hardly any adhesion between the metal foil and the substrate, which is convenient for removing this portion of the metal foil after stamping.

Since the die 3 of the present invention has the above-described structure, when stamping is performed, the blade part 1 cuts the metal foil 7 to form a circuit conductor as shown in FIG. 2 simply deforms the metal foil 7 into a concave shape by shearing, and characters etc. can be engraved without breaking the metal foil 7. In addition, FIG. 8 shows stamping with the die 3 on the metal foil 7 with the adhesive 8 on the insulating substrate 9, and as a result,
It can be engraved as shown in Figure 9. The manufacturing method will be explained below with reference to the drawings.

First, a die material 30 is prepared. die material 30
Usually, alloy tool steels such as SKS and SKD are used. The surface of the die material 30 that will become the stamping surface is chemically polished to a smooth plane. On the surface of the polished die material 30, a conductor contour 11 to be formed with an acid-resistant resist and characters etc. 12 to be formed within the conductor contour are drawn.

This operation covers the entire surface of the die material 30, e.g.
Apply an ultraviolet curable resin, place a negative film on the resin coating, irradiate it with ultraviolet rays to harden the exposed areas, and then remove the negative film.
This is immersed in a liquid that dissolves the uncured resin, and the uncured resin is dissolved and removed, leaving only the cured resin. In this way, the conductor outline and characters etc. are drawn on the surface of the die material 30 using the cured resin.

Prior to forming the conductor outline 11, characters, etc. 12 using the acid-resistant resist, artwork is created.
Artwork is done on a film or paper sheet that allows light to pass through using an automatic NC-controlled drawing machine, but it can also be done by inking, taping, etc. In this artwork, the line width dimension of the cured resin that forms the conductor outline, letters, etc. is calculated and selected based on the height of the completed die blade, but normally the conductor outline 11 has a line width of 0.1 to 2.0 mm.
It is determined by an appropriate value in the range of , and the line width of 12 characters etc. is drawn 0.1 to 0.4 mm thicker than that. For example, when the line width of the conductor outline 11 is 0.6 mm, the line width of the characters 12 is drawn to be 0.8 mm.

The die material 30 after forming the conductor contour 11 and characters 12 of the acid-resistant resist is filled with a liquid 13 that corrodes the die material 30, for example, when the die material 30 is SKS-based tool alloy steel, it is usually ferric chloride. A system etchant is used and immersed in it. By this immersion, the die material exposed portion 14 is melted, and the die material is scraped off to form a recess 15 as shown in FIG. Next, the cured resin is removed from the surface of the die material 30 on which the recess 15 is formed. There are various methods for removing the cured resin, but usually a chemical peeling method or a mechanical polishing method can be used.

In this way, conductor contours, characters, etc. are shaped into convex shapes 1
The die material 30 formed in 6 and 17 is again immersed in the corrosive liquid 13 as shown in FIG. Then, the narrow protrusion 16 forming the conductor contour is corroded by the corrosive liquid, resulting in a blade shape 1 with a sharp tip as shown in FIG.
will be formed. On the other hand, the wide convex portions 17 forming characters etc. are corroded around the flat surface of the tip of the convex portions and become rounded, forming a tooth pattern 2 as shown in FIG. This corrosive liquid 13 may be of the same type as the aforementioned corrosive liquid. In this way, die 3 is manufactured. However, as it is, the depth of the recess in the circuit conductor forming part (inner moat part) 18 and the board exposed part forming part (outer moat part) 19 of the circuit board is almost the same, so the inner moat part 18 is A filling 4 is provided. As the filler 4, a heat-resistant sheet, for example, a polychloroethylene sheet coated with a heat-resistant adhesive is used.

(Effects of the invention) As explained above, according to the invention, characters etc. to be engraved on the circuit conductor portion can be stamped simultaneously with punching of the circuit conductor, and as shown in FIG. 4, the metal foil 7 does not come into contact with the die 3 in areas other than the circuit conductor forming area during stamping, and therefore the metal foil 7 in these areas can be prevented from adhering to the insulating substrate 9.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the die of the present invention, and FIG. 2 is a sectional view taken along the line A--A in FIG. Figures 3 to 7 show the stages of manufacturing the die of the present invention. Figure 3 is a cross-sectional view of the die material with conductor contours and letters made of cured resin on the surface by artwork, and Figure 4. 5 is a cross-sectional view of a die material with an uneven surface formed by corroding the exposed parts of the die material other than the cured resin coating, and FIG. Figure 6 is a cross-sectional view of a die in which the conductor contour is formed into an acute-angled blade and the lettering is formed into a tooth by dipping the die material with unevenness into a corrosive liquid again, and Figure 7 shows a die made of heat-resistant material in the inner moat. FIG. FIG. 8 shows the state of stamping using the die of the present invention, and FIG. 9 shows the state of the remaining metal foil after stripping. FIG. 10 is a cross-sectional view of a conventional die. DESCRIPTION OF SYMBOLS 1... Blade, 2... Teeth, 3... Die, 4... Heat-resistant material, 11, 12... Acid-resistant resist, 13... Corrosion liquid, 7... Metal foil, 8... Adhesive layer, 9 ...Insulating board.

Claims (1)

[Scope of utility model registration request] A blade shape with an acute tip that forms the conductor contour for forming a circuit conductor on the surface of the die, and a flat tip that is used to engrave characters, symbols, diagrams, etc. on the circuit conductor, and the surrounding area thereof. 1. A die for manufacturing a printed circuit by a die stamping method, characterized by having a rounded tooth shape and a filling provided on the inner surface of a portion surrounded by the blade shape.