JPH11214822A - Drilling method for printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy of working position when making an elliptic hole by using a drill. SOLUTION: At first, a plurality of holes 13 with a diameter smaller than the length of a short side of an elliptic hole 2 are drilled along a circular arc portion of one end side 2a of the elliptic hole 2, then, a circular hole 14 is drilled at the other end side 2b of the elliptic hole 2 by using a drill having a diameter equal to the length of the short side of the elliptic hole 2, moreover, a circular hole 15 is drilled at one end side 2a of the elliptic hole by using a drill having the diameter equal to the length of the short side of the elliptic hole 2, thereby avoiding the overlapping of the center positions of any drills and further, the drilling is performed by boring each drill into the printed circuit board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for drilling a printed wiring board, and more particularly to a method for drilling a printed wiring board capable of accurately drilling an oval hole.

[0002]

2. Description of the Related Art Conventionally, a method of forming an elliptical hole using an NC drill in a printed wiring board is performed by partially overlapping two or more circular holes in the printed wiring board to form a hole. ing.

That is, as shown in FIG.
In order to form the oblong hole 2 on the upper side, a method of forming an oblong hole by performing continuous processing sequentially from one side of the oblong hole 2 is generally used. In the conventional method shown in FIG. 5, the first circular hole 3a is accurately drilled with an accuracy of 0.05 to 0.10 mm, which is equivalent to ordinary drilling. As shown in FIG. 6, when drilling a hole with the drill 4 after the second, the force of the drill 4 escapes to the space on the left side, so that the drill 4 shifts in the arrow direction 5.

The drill 4 is rotating at a high speed, and when the rotation direction is the rotation direction (clockwise direction) 6 shown in FIG. This gap is 0.
The deviation was as large as 10 to 0.50 mm, which was a serious problem.

As a method for solving this problem, Japanese Patent Laid-Open No.
According to the technology disclosed in JP-A-352487, FIG.
As shown in (1), first circular holes 8a and 8b are formed at both ends in the longitudinal direction for forming the oblong hole 2.

[0006] Next, a circular hole 8c is formed at a center position between the two first circular holes 8a and 8b, and then a hole is formed at a central position 8d and 8e between the respective circular holes to form an oval hole as a whole. Is formed.

According to the technique disclosed in Japanese Patent Application Laid-Open No. Hei. 5-1608, as shown in FIG. 9, one of the circular holes 9a and 9b adjacent to each other is concentric with and smaller than one circular hole 9b. And a pilot hole 10 not in contact with the other circular hole 9a
And an oval hole is formed as a guide hole when the circular hole 9b is drilled.

Further, according to the techniques disclosed in JP-A-2-274409 and JP-A-2-185307,
As shown in FIG. 10, a large circular hole 11 is formed by making a small diameter circular hole 12 along the inner periphery.

[0009]

However, the above-described conventional manufacturing method has the following problems. That is, JP-A-4-352487 shown in FIG.
The technique disclosed in JP-A-5-16008 shown in FIG. 9 has no effect when the length direction of the oval hole is short, and there is a problem in the position accuracy of the oval hole.

The reason is that a hole is drilled at one end of the oblong hole and then the other hole is machined. When one hole is machined, the existing hole shown in FIG. With the power to shift,
This is because a repulsive force is generated due to the rotation of the drill 4 shown in FIG. In particular, if there are 30 circular holes
If they overlap by more than%, a shift occurs.

[0011] Further, as shown in FIG.
In the technology disclosed in Japanese Patent Application Laid-Open No. 9-185307 and Japanese Patent Application Laid-Open No. 2-185307, when a small diameter hole is drilled along a tangent line on the inner circumference, the small diameter circular holes overlap, and the position of the drill is shifted and the dimensional positional accuracy is shifted. And the drill is broken.

An object of the present invention is to provide a method for drilling a printed wiring board which improves the processing position accuracy of an oblong hole.

[0013]

In order to achieve the above object, a method for drilling a printed wiring board according to the present invention is a method for drilling an oval hole in a printed wiring board using a drill, A plurality of second circular holes that are smaller in diameter than one of the first circular holes adjacent to each other and that are in contact with the circumference are machined, and then the first circular holes adjacent to each other are processed. A third circular hole having the same diameter as the other circular hole is machined, and a fourth circular hole having the same diameter as the first circular hole on the side where the second circular hole is provided.
The above-mentioned elliptical hole is drilled by processing the circular hole.

Further, three second circular holes are provided along an arc portion of the first circular hole.

The three positions for machining the second circular hole are varied depending on the diameter of the drill to be used and the pitch between the hole centers of the third and fourth circular holes.

Further, when the pitch of the hole centers of the third and fourth holes is smaller than the radius of the holes, the first hole is the third or fourth hole. A hole is formed at a position of a circle that is in contact with the starting point, the ending point, and the center of the arc portion of the circular hole of No. 4.

Further, the third or fourth circular hole may be arranged such that when the pitch of the hole centers of the third and fourth circular holes is larger than the radius of the circular hole and smaller than 1.4 times the radius, The center of the third or fourth circular hole is machined by shifting in the direction of the fourth or third circular hole by an amount larger than the radius.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 are views showing a method for punching a printed wiring board according to an embodiment of the present invention, and FIGS. 1 (a) to 3 (a) are plan views showing drilling positions. 1 (b) to 3 (b) are cross-sectional views of the same, and FIG. 4 is a view showing the size of a circular hole.

First, the NC drill is moved to a position where the oblong hole 2 of the printed wiring board 1 is formed. Next, as shown in FIG. 1, before forming the oval hole 2, a circular hole 13 having a smaller diameter than the short side length of the oval hole 2 is formed along the arc portion of one end 2 a of the oval hole 2. Dawn. In this case, the NC drill 4a has a diameter smaller than the length of the short side of the oblong hole 2, and the small-diameter hole 13 has a starting point and an ending point of an arc portion at one end 2a of the oblong hole 2. And drilling at three places, the center of the starting point and the center of the ending point. At this time, since the drill 4a is formed in the printed wiring board 1 itself, the circular hole 13 can be formed at a predetermined position without receiving a biased force.

Next, as shown in FIG. 2, a circular hole 14 is formed in the other end 2b of the oval hole 2 by using an NC drill 4b having a diameter equal to the length of the short side of the oval hole 2. . At this time, circular hole 1
It is conceivable that the drill 4b partially overlaps the previously drilled circular hole 13. However, since the drill 4b is drilled in the printed wiring board 1 itself, the drill 4b does not receive a biased force. 14 can be drilled along the arc of the other end 2b of the oblong hole 2.

Next, as shown in FIG. 3, a circular hole 15 is formed in one end 2a of the oval hole 2 using an NC drill 4c having a diameter equal to the length of the short side of the oval hole 2. This NC drill 4c has the diameter of the short side of the oblong hole 2 as a diameter.
It has the same diameter as the NC drill 4b. At this time, the circular hole 15
The drill 4c for drilling a hole is formed on the printed wiring board 1 in the remaining portion around the circular hole 13 whose center position has already been drilled.
The hole is formed only at the upper position, without receiving a biased force, and the circular hole 14 can be drilled along the arc portion of the other end 2b of the oblong hole 2.

As described above, in the embodiment of the present invention, first, a plurality of circular holes 13 having a smaller diameter than the short side length of the oblong hole 2 are formed along the arc portion of one end 2a of the oblong hole 2. ,
Next, an NC drill 4b having the diameter of the short side of the oval hole 2
A hole 14 is formed in the other end 2b of the oval hole 2 by using a hole, and a hole 15 is formed into an oval hole by using an NC drill 4c having a diameter of the short side of the oval hole 2. Since one end side 2a of the drill 2 is drilled, the center positions of the drills 4a, 4b, 4c do not overlap, and the drills 4a, 4b,
4c cuts into the printed wiring board 1 and drills, so that there is no displacement of the circular holes 13, 14, 15 and the circular holes 13, 14, 15 can be drilled at accurate positions. it can.

Here, the size of the circular hole 13 will be described. As shown in FIG. 4, the circular hole 13 is a circle that is in contact with a line obtained by dividing a circular hole 16 having a diameter equal to the short side length of the oblong hole 2 into four. 0.41 of diameter
The drill 4c is quadruple, and the drill 4c whose diameter is enlarged in 0.05 mm units is used. Also, the fact that the diameter of the circular hole 16 is 0.414 times that of the triangles S1, S2, S
It can be derived from the relationship between 3 and the circular hole 13.

The positions of the three holes for machining the circular holes 13 vary depending on the drill diameter of the circular holes 13 to be used and the pitch of the hole centers of the circular holes 14 and 15. However, if the radius is smaller than the radius of the circular hole, the circular hole 13 is machined at a position of a circle that is in contact with the starting point, the ending point, and the center of the arc portion of the oblong hole 2, and is larger than the radius and 1.4 times the radius If smaller, the center of the circular hole 15 is machined by shifting in the direction of the circular hole 14 by an amount larger than the radius. If the radius is larger than 1.4 times, this drilling method is not applied, and ordinary elliptical hole processing is performed.

[0026]

As described above, according to the present invention, a plurality of holes smaller than one of the holes are machined in advance in the holes adjacent to each other before forming a long hole circle. Therefore, at present, the processing position accuracy of 0.1 to 0.5 mm due to the bias of the rotational force can be raised to the original processing position accuracy of the drill of 0.05 to 0.1 mm.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a method for making holes in a printed wiring board according to an embodiment of the present invention, wherein FIG. 1A is a plan view showing a hole processing position, and FIG.

FIGS. 2A and 2B are diagrams illustrating a method of punching a printed wiring board according to an embodiment of the present invention, wherein FIG. 2A is a plan view illustrating a hole processing position, and FIG.

3A and 3B are diagrams illustrating a method of punching a printed wiring board according to an embodiment of the present invention, in which FIG. 3A is a plan view illustrating a hole processing position, and FIG.

FIG. 4 is a view showing the size of a circular hole in the method for boring a printed wiring board according to the embodiment of the present invention.

FIG. 5 is a plan view showing a method for punching a printed wiring board according to a conventional example.

FIG. 6 is a sectional view taken along line a-a ′ of FIG. 5;

FIG. 7 is a diagram showing a method of punching a printed wiring board according to a conventional example.

FIG. 8 is a diagram showing a method of punching a printed wiring board according to a conventional example.

FIG. 9 is a diagram showing a method of punching a printed wiring board according to a conventional example.

FIG. 10 is a diagram showing a method of punching a printed wiring board according to a conventional example.

[Explanation of symbols]

 Reference Signs List 1 printed wiring board 2 oval hole shape 3a-3b circular hole 4a, 4b, 4c drill 13 circular hole 14, 15 circular hole 16 circular hole

[Procedure amendment]

[Submission date] April 26, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

[0013]

In order to achieve the above object, a method for forming a hole in a printed wiring board according to the present invention comprises the steps of :
The first circular hole having a diameter smaller than the short side length of the oval hole
A plurality of holes are drilled along an arc portion on one end side of the second hole, and then a second hole having a diameter equal to the short side length of the oblong hole to be drilled.
Drilling a circular hole at the other end side of the oblong hole, and forming a third hole having a diameter equal to the short side length of the oblong hole to be drilled.
Is formed in one end of the oblong hole .

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

[0014] The first circular hole, the three drilling along one side arc portion of the oval hole.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

[0015] position of the three positions for processing the first circle hole, Ru varied by the pitch diameter and the second and third hole center of the circle hole of the drill to be used.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

[0016] When the pitch of the previous SL second and third hole center of the circle hole is less than the radius of the second and third circles hole, the
1 of circular hole is drilled in the position that Sessu to the start and end points and the center of the circular arc portion of the elongated circle hole.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

The second or third circular hole is provided in the second or third circular hole.
If the pitch of the hole centers of the second and third holes is larger than the radius of the hole and smaller than 1.4 times the radius, shift toward the third or second hole by an amount larger than the radius. By doing so, the center of the second or third circular hole is machined.

Claims (5)

[Claims] 1. A method for drilling an oblong hole in a printed wiring board using a drill, wherein the diameter of the first circular hole is smaller than the diameter of one of the first circular holes adjacent to each other, and the first circular hole is formed in a circumferential direction. Processing a plurality of second circular holes that are in contact with each other, and then processing a third circular hole having the same diameter as the diameter of the other circular hole among the first circular holes adjacent to each other; Forming an elliptical hole by forming a fourth circular hole having the same diameter as the diameter of the first circular hole on the side where the circular hole is provided. Method. 2. The method according to claim 1, wherein three second circular holes are provided along an arc portion of the first circular hole. 3. The method according to claim 1, wherein the three positions for machining the second circular hole are varied depending on a drill diameter to be used and a pitch between hole centers of the third and fourth circular holes. Item 3. The method for drilling a printed wiring board according to Item 2. 4. The second circular hole, if the pitch between the hole centers of the third and fourth circular holes is less than or equal to the radius of the circular hole, the first circular hole is the third or fourth circular hole. 4. The method according to claim 3, wherein a hole is formed at a position of a circle that is in contact with the start point, the end point, and the center of the arc portion of the circular hole of No. 4. 5. The third or fourth circular hole is provided with the third circular hole.
And when the pitch of the hole center of the fourth circular hole is larger than the radius of the circular hole and smaller than 1.4 times the radius, it is shifted toward the fourth or third circular hole by an amount larger than the radius. 2. The method according to claim 1, wherein the center of the third or fourth circular hole is processed.