JPS6017675B2 - How to punch out laminates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a single-sided punching die with a punching section consisting of a group of hole-drilling punches and a punch for thinning and smoothing the wall surface of the hole formed by the punching section. The present invention relates to a method for punching a laminate using a mold having a finishing section consisting of groups.

With the recent trend toward high-density mounting of pin-wire devices, the use of through-hole boards has become popular in order to increase the wiring density of printed wiring boards.

In the semi-industrial field, which was created due to the transition to consumer products related to information processing technology that was previously thought to be industrial, glass cloth-epoxy resin laminates and glass nonwoven fabric-epoxy resin laminates are being used as substrates for printed circuit boards due to reliability. Boards, etc. are used, and in terms of price, it is desired that the price be as low as in the consumer equipment field. Therefore, as a response to lower prices of printed wiring boards in the semi-industrial field, it is desired to develop a punching method instead of the conventional drilling method for through-hole processing. In general, the characteristics of punched holes are that the blank is inserted between the punch and die hole of the punching die, and the hole is formed by the cracks that occur in the blank, so the hole is smaller than that of a drilled hole. The wall roughness increases.

Therefore, the shape of through-hole plating applied to a punched hole is more uneven than that of through-hole plating applied to a drilled hole, and is evaluated to be unreliable. In recent years, in order to improve the above-mentioned problem, a punching method has been developed in which the wall surface of the hole obtained by punching is further smoothed by using a second punch.
(hereinafter referred to as the shaving processing method) was proposed.

More specifically, a punching section consisting of a group of punches for making holes and a finishing section consisting of a group of punches for sharpening and smoothing the edge surface of the hole formed in the punching section are provided on one side of the mold, and the blank is punched. This is a processing method in which punching is performed sequentially from the section to the finished section. However, there are serious problems with the above shaving method.

That is, the punching powder generated when cutting the wall surface of the punched hole in the finishing section is removed from the blank. For shaving molds, the punches in the punching section and finishing section are designed to have the same length, and the depth of penetration of the punch into the die hole in the punching section and finishing section when punching a blank is set to the same length as in the punching process for general laminates. Adjust the Planck thickness to about 2'3 on the same plane. When shaving is performed at the penetration depth, the plank is sandwiched between the punch and the die hole at the punching part, and is broken and punched out due to the crack that occurs on the line connecting the punch edge and the die hole edge, and the punching powder is removed. It is pushed into the die hole. However, in the finishing part, unlike the punching part, the hole wall surface formed in the punching part is scraped with a punch edge, so that the separation of the punching powder from the blank is insufficient. In addition, the shape of the punching powder in the finishing part is cylindrical and it is finer than the punching powder generated in the punching part, so when the punch is pulled out from the blank after punching, there is an accident in which the punching powder is drawn into the hole. It is easy to cause Therefore, the following two problems occur regarding punching powder in the finishing section. First, removing the cylindrical punching powder or fine powder adhering to the vicinity of the hole in the finishing section requires a process such as brushing, which causes a considerable drop in work efficiency. Secondly, when the punch is pulled out from the blank, the punching powder drawn into the hole is pressed against the wall of the hole due to the frictional heat generated between the punch and the blank. This phenomenon is
When the blank is a glass cloth-evoxy resin laminate, the appearance is very similar to a smear, and the punching powder cannot be removed sufficiently even if the inside of the hole is washed with high pressure. The shape of through-hole plating applied to such punched holes is evaluated to be more uneven and unreliable than through-hole plating applied to drilled holes. The purpose is to prevent

That is, in the present invention, the depth of penetration of the finishing part punch into the die hole during blank punching is set to be 0.3 to 3 bars longer than the penetration depth of the punch of the punching part into the die hole during blank punching. It is a punching method, preferably a processing method in which the sail is lengthened by one length and then punched out.

Even if the penetration depth of the finishing part punch into the die hole when punching the blank is greater than the penetration depth of the punch of the punching part into the die hole when punching the blank, if the difference is 0.3 mm. , a lot of punching powder adheres to the area around the finished hole.

Furthermore, if the difference in penetration depth exceeds three sides, the metal foil on the punch penetration side of the blank metal foil-clad laminate will swell up when the punch is pulled out after punching. Next, examples of the present invention will be described.

The penetration depth of the punch into the die hole during blank punching of the punching part and finishing part of the mold is 1.
An epoxy resin double-sided steel-clad laminate (glass cloth as a base material on both surfaces of the laminate, glass nonwoven fabric as an intermediate layer) having a thickness of 1.6 to 1.6 ribs was punched out.

The test results for the punched holes are shown in Table 1. The depth of penetration into the die hole during blank punching of the punch in the punching part and finishing part in the comparative mold was 1.
1 side, and punched out a double-sided steel clad laminate similar to the example.

The test results for the punched holes are shown in Table 1. Table 1 ×-1 Punching powder adhesion rate = Number of holes XI to which punching powder (cylindrical) adheres.

. (Total number of punched holes for chicks: 12) Through-hole plating: After high-pressure cleaning, 25mm thick through-hole plating is applied.

As is clear from Table 1, according to the present invention, there is no adhesion of punching powder around or inside the punched hole, so brushing around the punched hole or cleaning inside the punched hole is reduced, and through-hole plating can also be done with a drill. Its industrial value is extremely great, as there is no discernible difference from when it is applied to a hole.

Claims (1)

[Claims] 1. When punching a laminate board with a mold that has a punching section consisting of a group of punches for making holes and a finishing section consisting of a group of punches for thinning and smoothing the wall surface of the hole formed by the punching section, The punching feature is that the depth of penetration of the punch in the finishing section into the die hole of the mold when punching the blank is 0.3 to 3 mm longer than the depth of penetration of the punch in the punching section into the die hole of the die when punching the blank. A method for punching laminates.