JPS62287686A - Printed wiring board and manufacture of the same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 1. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a printed wiring board and a method for manufacturing the same, and in particular to through holes for mounting electronic components on printed wiring boards and through holes for conduction between the front and back surfaces. The present invention relates to the shape of an external end face located close to a hole such as a hole, and a method of processing the same.

[Conventional technology]

Conventionally, the external shape of the end face in the vicinity of the hole provided in the printed wiring board was previously drilled using a hole IN/C drilling machine, etc., and after performing through-hole plating as necessary, punching with a press mold, etc. Therefore, the outer shape of the hole is pressed once larger than the predetermined size at a position where the hole does not cause distortion, and then the outer shape is framed and finished to the specified size, or the hole is formed by router processing.

[Problem that the invention seeks to solve]

For this reason, in the former case of the conventional example, since the outer shape of the printed wiring board is punched, the end face of the outer contour near the hole is crushed by the impact during shearing, causing strain in the hole. There was a drawback that the punch was punched out thickly in a position that would not have any effect. Further, when this dimension is reduced, there is a drawback that distortion occurs in the hole. Therefore, when mounting electronic component leads by inserting them into these holes, it was not possible to easily insert the electronic component leads. On the other hand, in a through hole where a plating layer is applied to the hole wall surface, a part of the plating layer may be damaged, causing an abnormality in which the conductive connection between the front and back surfaces of the printed wiring board is broken.

In addition, in the latter type of router machining in the conventional example, the cutting process is used for router bits, and each end face of the external shape is finished in a clean and uniform state, so it takes a lot of machining time, and it is difficult to process mass-produced products. had some disadvantages that made it unsuitable.

[Means for solving problems]

An object of the present invention is to provide a printed wiring board and a method for manufacturing the same that solves the above conventional drawbacks.

According to the present invention, the end face portion of the notch of the minute circular arc portion is obtained at a pitch interval opposite to a plurality of through holes provided close to each other along the edge of the external contour. There is also a step of forming a first through hole along an edge of the printed wiring board;
forming a second through hole with the same gap as the through hole;
A method for manufacturing a printed wiring board is obtained, which includes the step of forming the external shape of the printed wiring board into a press mold and cutting the printed wiring board at a position where a diameter of 1710 mm or less of the diameter of the second through hole remains on the external outline.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a perspective view of the printed wiring board of the present invention.

In the figure, reference numeral 1 indicates a printed wiring board having a circuit pattern (not shown) on the front and back surfaces of an insulating board such as a glass epoxy resin;
is a through hole that connects the front and back surfaces of the printed wiring board. Reference numeral 3 indicates an end face having an outer shape cut out by punching with a press die, and shows an end face where the outer outline is relatively distant from the hole provided in the printed wiring board surface. Reference numeral 4 indicates a micro-arc portion provided in the vicinity of the through-hole hole 2; 5 indicates a micro-arc portion 4;
This is one end surface of the outer contour formed by the .

Next, a method for manufacturing a printed wiring board according to the present invention will be explained with reference to FIGS. 2 to 4.

First, as shown in FIG. 4, an insulating plate 9 made of glass epoxy resin or the like for forming a printed wiring board is blanked to a predetermined size that can be processed into a printed wiring board.

Next, pilot holes 2C of through-holes used for conductive connection are formed in the patterns on the front and back surfaces of the printed wiring board using an N/C drilling machine or the like. During this step, a second through hole 7 is bored at a position opposite to the first through hole provided close to the edge of the outer contour, that is, outside the outer contour area.

Next, the relationship between the hole position and hole diameter during the above-mentioned process will be explained using FIG.

FIG. 3 is an enlarged plan view of the first through-hole and second through-hole portions in which a circuit has been formed after the well-known through-hole plating and development/etching processes are completed.

The front and back edges of the through-hole hole 2 are provided with lands 2A and a circuit pattern 2B. This is indicated by an external contour line f'i6. The distance between the hole wall of the through-hole hole 2 and the external contour line is generally the distance greater than the board thickness of the printed wiring board shown in Figure 1, but in recent years, as devices have become smaller, the printed wiring density has increased. has increased, and things less than t are needed. Therefore, it is necessary to drill the second through-hole 7 so that the through-hole hole 2 is not deformed by the shear VJ impact of the punching process using the press die. The position of the through hole 7 is such that after the outer shape is formed by punching with a press die, 1/10 or less of the diameter Dφ of the through hole remains at the edge of the outer shape, and the same dimension pitch as the through hole hole 2. Drill holes at the same intervals. Therefore, the diameter of the second through hole is determined by the two dimensions. If the two dimensions are small and the diameter Dφ is large, the drill will come into contact with the 11J hole and break during N/C drilling, resulting in a bad shape 41. Also, 2 dimensions are 2
In the case of a relatively large pitch size of about 51131, 2
Using a drill diameter of about φ, there is no drill breakage and it is efficient.
Can be drilled.

Next, a process in which the outer end surface portion 5 adjacent to the through-hole hole 2 is formed into the minute circular arc portion 4 will be described with reference to FIGS. 3 and 4.

By forming the second circular holes 7 in the above-described process, the mesh of glass cloth in the insulating substrate is cut and divided by the through holes. Then, using a punching section in which a mold punching reference pilot pin of a mold (not shown) is arranged, three press pilot holes 8 of the insulating substrate 9 shown in FIG. 4 are aligned and punched. At this time, the second
The mold is designed so that the diameter of the press mold is 1/10 or less between the position where the circular hole is drilled and the cutting edge of the press mold for forming the outline of the printed wiring board. A punching reference pilot pin and a pilot hole 8 of the printed wiring board are provided.

Therefore, press punching can be performed accurately on the line connecting the positions where 1/10 or less of the second through-hole 7 is left, and the external end face adjacent to the through-hole 2 can be punched without damaging the adjacent through-hole. 5 can be formed into a minute circular arc portion.

〔Effect of the invention〕

As described above, the present invention has the following effects.

(1) By drilling a second circular hole along with the first through-hole, etc., a printed circuit board can be processed with a small remaining size of the hole and external outline without the need for any special process. However, we can handle press processing.

(!1) During the shear punching process of the press die, the second circular hole is drilled outside the area of the end face where the hole is close to, so the finished end face has less remaining dimension from the hole wall to the external outline. This has the advantage that the holes can be provided without destroying them.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a printed wiring board according to one embodiment of the present invention, and FIG.
The figure is an enlarged plan view showing the positional relationship between the first circular hole and the second circular hole of the present invention, FIG. FIG. 2 is a perspective view of an insulating substrate according to an example. 1...Printed wiring board, 2...Through hole, 2 people...Land, 2B...Circuit pattern, 2C...Prepared hole , 3...---outer end surface, Dφ...(diameter of the second circular through hole),
4...Minute circular hole part, H...Remaining dimensions (of the minute circular hole part), End part...(close to the hole) external end surface part, P... ... Hole pitch, 6 ... Outline, t ... Plate thickness, 7 ... - Second circular through hole, 8 ... (Substrate ) Pilot hole, 9.
・・・−・Insulating board.・＼ -l i:1=pregnancy; no m

Claims (2)

[Claims] (1) Printed wiring characterized by having a plurality of through holes provided close to each other along the edge of the external contour, and an end surface of a notch of a minute circular arc portion at a pitch interval opposite to the through holes. substrate. (2) forming a first through hole along the edge of the printed wiring board; forming a second through hole with the same gap as the first through hole; A method for manufacturing a printed wiring board, comprising the step of cutting the outer shape using a press mold at a position where 1/10 or less of the diameter of the second through hole remains at the edge of the outer shape outline.