JPH0516008A - Punching method for printed wiring board - Google Patents

Abstract

PURPOSE:To provide a punching method for a printed wiring board in which elliptic holes having no misregistration can be punched easily and surely. CONSTITUTION:A punching method for a printed wiring board for forming elliptic holes 5 by punching a plurality of circular holes 2, 3 in the printed wiring board 1 by means of a drill in the state that the holes are partially overlapped each other is provided, in such a manner that whether lead hole 4 concentric with one circular hole 3 out of mutually adjacent circular holes 2, 3 and, smaller than the hole 3, and not in contact with the other circular hole 2 is punched of the circular hole 3, a concentric circle with the lead hole 4, is punched after the other circular hole 2 is punched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of punching a printed wiring board for forming an elliptical hole by punching a plurality of circular holes so as to overlap each other.

[0002]

2. Description of the Related Art Conventionally, as a method of forming an elliptical hole in a printed wiring board, an NC drill is used, and two circular holes are partially overlapped and punched in the printed wiring board. .. That is, as shown in FIG. 7, a drill (not shown) is arranged on one end side of the printed wiring board 1 forming the elliptical hole to open the first circular hole 2.

Subsequently, as shown in FIG. 8, the drill is shifted to the right in the drawing to change its position, and a second circular hole 3 is formed so as to partially overlap the first circular hole 2. In this way, the elliptical hole 5 in which the first circular hole 2 and the second circular hole 3 are connected is formed.

[0004]

However, in the conventional drilling method described above, the position of the first circular hole 2 to be drilled first is accurate, but the second circular hole 3 to be drilled next is the same as the first circular hole 3 to be drilled. A slight displacement occurs in the direction away from the circular hole 2. That is, FIG.
As shown in FIG. 2, when the second circular hole 3 is to be drilled, if the cutting edge 7 at the tip of the drill 6 does not reach the side wall of the first circular hole 2 that was previously drilled, the drill 6 is It descends toward a predetermined position (two-dot chain line in the figure) for making the circular hole 3.

However, as shown in FIG. 10, when the cutting edge 7 at the tip of the drill 6 reaches the side wall of the first circular hole 2, the drill 6 receives force from the side wall in the direction of the arrow in the figure. Next, as shown in FIG. 11, when the drill 6 is further lowered, the resistance received in the original traveling direction of the drill 6 is almost the same as the resistance received in the other directions. It descends straight as it is. Therefore, the second circular hole 3 is formed at a position slightly displaced from the predetermined position, that is, at a position displaced rightward in the drawing.

As a result, the oval hole 5 formed by the first circular hole 2 and the second circular hole 3 is displaced from the predetermined position, and the desired oval hole is not formed. was there.

The present invention has been made in order to solve the above problems, and an object thereof is to make a hole in a printed wiring board in which an elliptical hole with no displacement can be easily and surely made. To provide a method.

[0008]

To achieve the above object, in the present invention, a drill is used to form a plurality of circular holes in a printed wiring board so as to partially overlap each other, thereby forming an elliptical hole. A method of forming a hole in a printed wiring board for forming a lead hole, which is concentric with one circular hole of adjacent circular holes and smaller than that, and which does not contact the other circular hole or the other circular hole. After that, the gist is a method of drilling a printed wiring board in which one of the concentric circles with the lead hole is drilled.

[0009]

First, of the circular holes which are adjacent to each other and partially overlapped with each other, a lead hole which is concentric with one circular hole and smaller than the circular hole and which does not contact the other circular hole is formed, or the other circular hole is formed. Make a hole. Since these lead holes or the other circular holes are independently formed on the printed wiring board, the lead holes or the other circular holes can be accurately formed at predetermined positions without causing positional displacement. Next, one circular hole that is concentric with the lead hole is opened.

At this time, when the cutting edge portion of the drill tip reaches the side wall of the other circular hole that was previously drilled, a force is applied from this side wall to the outside of the other circular hole, but the lead hole is pre-drilled. Since the lead hole is not resistant to the drill, the drill is guided by the lead hole and goes straight. Therefore, one of the circular holes, which will be opened later, can be opened at a predetermined position without causing displacement. As a result, an oval hole formed by connecting both of these circular holes is formed at a predetermined position.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to FIGS. In this embodiment, two adjacent
A method of forming an oval hole by opening two first and second circular holes of the same size so as to partially overlap each other will be described. The same parts as those of the conventional example will be described using the same reference numerals.

First, as shown in FIGS. 1 and 2, a lead hole 4 which is concentric with the second circular hole 3 and smaller than the second circular hole 3 and which does not overlap the first circular hole 2 is formed. Set.
Then, a drill (not shown) is arranged above the center of the lead hole 4. Then, the drill is lowered to open the lead hole 4. At this time, since the lead hole 4 is opened in the printed wiring board 1 itself, there is no risk of receiving a biased force, and therefore the lead hole 4 can be opened in a predetermined position without causing displacement.

Next, as shown in FIG. 3, the first circular hole 2 is opened at a predetermined position where it does not overlap with the lead hole 4. At this time, since the first circular hole 2 is formed in the printed wiring board 1 itself like the lead hole 4, the first circular hole 2 can be formed in a predetermined position without displacement.

Next, as shown in FIG. 1, the lead hole 4 is formed.
A second circular hole 3 is opened at a position concentric with. At this time, as shown in FIG. 4, the cutting edge 7 at the tip of the drill 6 is the first
Until it hits the side wall of the circular hole 2, the second circular hole 3 is lowered toward a predetermined position (a chain double-dashed line in the same figure). Then, as shown in FIG. 5, when the cutting edge 7 of the drill 6 reaches the side wall of the first circular hole 2, the drill 6 receives a resistance force from the side wall, so that the drill 6 is located outside the first circular hole 2, That is, the force is applied to the right in the figure.

However, as described above, the lead hole 4
Is opened in advance so as to guide the drill 6 in advance. Therefore, when the drill 6 is further lowered, as shown in FIG.
As shown in, since there is no resistance at the lead hole 4,
The drill 6 is guided by the lead hole 4, returns to the original traveling direction, and descends straight along that direction.
As a result, the second circular hole 3 is not substantially displaced. Thus, the elliptical hole 5 in which the first circular hole 2 and the second circular hole 3 are connected is formed. This oval hole 5 can be surely opened at a predetermined position with high positional accuracy.

As described above, when the second circular hole 3 is opened, the drill 6 receives the resistance force from the side wall of the first circular hole 2 to the outside thereof. This is the case where the second circular holes 3 overlap little, for example, 30% or less. Further, regardless of the hole diameters of the first and second circular holes 2 and 3, the positional displacement of both circular holes 2 and 3 does not occur. The holes 5 are in place.

The present invention is not limited to the above embodiment, but may be embodied as follows. (1) In the above embodiment, the first circular hole 2 and the lead hole 4
The order of opening the second circular hole 3 may be as follows. That is, first, the first circular hole 2 is formed, and then the lead hole 4 is formed. Next, the second circular hole 3 may be formed at a position concentric with the lead hole 4. (2) The lead hole 4 does not necessarily have to penetrate, and it is sufficient that the lead hole 4 reaches the lower part of the printed wiring board 1. (3) The number of circular holes adjacent to each other may be three or more. In that case, it is necessary to provide the lead holes 4 corresponding to the number of circular holes.

[0018]

According to the present invention, it is possible to easily and surely open an oval hole that does not cause a positional deviation.

[Brief description of drawings]

FIG. 1 is a partial plan view showing an embodiment of the present invention and showing a state in which elliptic holes are formed by sequentially forming circular holes in a printed wiring board.

FIG. 2 is a partial plan view showing a state in which lead holes are formed in a printed wiring board.

FIG. 3 is a partial plan view showing a state in which lead holes and first circular holes are opened in a printed wiring board.

FIG. 4 is a cross-sectional view showing a state in which the tip of the drill reaches the printed wiring board when the second circular hole is formed.

FIG. 5 is a cross-sectional view showing a state in which the cutting edge of the tip portion of the drill approaches the side wall of the first circular hole when the second circular hole is opened.

FIG. 6 is a cross-sectional view showing a state where the drill is further lowered from the state of FIG.

FIG. 7 is a partial plan view showing a conventional example and showing a state in which a first circular hole is opened in a printed wiring board.

FIG. 8 is a partial plan view showing a state where a second circular hole is further opened from the state of FIG.

FIG. 9 is a cross-sectional view showing a state in which the tip of the drill reaches the printed wiring board when the second circular hole is formed.

FIG. 10 is a cross-sectional view showing a state where the cutting edge of the tip of the drill approaches the side wall of the first circular hole when the second circular hole is opened.

11 is a cross-sectional view showing a state in which the drill is further lowered from the state of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printed wiring board, 2 ... 1st circular hole as another circular hole, 3 ... 2nd circular hole as one circular hole, 4 ... Lead hole, 5 ... Elliptical hole, 6 ... Drill.

Claims (1)

Claim: What is claimed is: 1. A drill (6) is used to form a plurality of circular holes (2, 3) in a printed wiring board (1) in such a manner that they partially overlap each other. A method of punching a printed wiring board for forming a circular hole (5), which is concentric with one circular hole (3) of adjacent circular holes (2, 3) and smaller than the circular hole (3), and Open the lead hole (4) that does not contact 2) or the other circular hole (2)
After drilling, one hole (3) concentric with the lead hole (4) is drilled.