JPS623889A - Piercing method for printed board - Google Patents

Abstract

PURPOSE:To perform a piercing without any displacement for a wiring pattern by forming a wiring pattern on a printed board, by detecting the shape and size of the wiring pattern part where a through hole is to be made and by deciding the position to be pierced. CONSTITUTION:Wiring patterns 2A, 3A and 2B, 3B, etc. are formed on a printed board 1 prior to piercing a through hole 4 on the printed board 1. The shape and size of the wiring pattern part 3A where the through hole 4 is to be pierced on the printed board 1 are detected by a wiring pattern image pickup device. Based on this detected result, the position to be pierced is decided and the piercing is performed by the laser beam, etc. on this decided position. The piercing of the through hole can thus be performed without any displacement for the wiring pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a method for drilling holes in printed circuit boards, and is particularly suitable for use in drilling through holes on wiring patterns.

B. Summary of the Invention The present invention provides a printed circuit board hole processing method for drilling through holes in a printed circuit board, in which a wiring pattern is formed on the printed circuit board before drilling the through holes, and the shape and size of the wiring pattern portion are determined. By reading this to determine the position to be drilled, misalignment between the wiring pattern and the through hole can be easily eliminated.

C. Conventional technology In printed wiring boards, the fourth method is used to electrically connect the front side wiring pattern to the back side wiring pattern.
As shown in the figure and FIG.
There is a through hole (this is called a through hole) 4 that passes through the land 3A, the printed circuit board 1, and the land 3B at approximately the center of B.
By drilling a hole and forming a plating layer 5 on the inside of this through hole 4 using a 4-electroconductive material, such as solder,
A structure in which the lands 3A and 3B are electrically connected by the plating layer 5 is used.

In order to obtain an electrical connection structure having such a configuration, conventionally, a through hole is first drilled in the printed circuit board 1 using, for example, a drill, and then the inside of the through hole is plated with a conductive material, and then the front and back surfaces of the printed circuit board 1 are plated. A processing method has been adopted in which a wiring pattern is formed by performing a pattern etching process on the substrate.

D Problems to be Solved by the Invention However, according to this method, after a through hole is drilled in the printed circuit board 1, a screen for pattern etching is positioned so as to be aligned with the through hole 4, and this screen is used. During processing steps such as printing and forming a wiring pattern, there is a risk that the lands 3A and 3B may be misaligned with respect to the through-hole 4, and if such misalignment occurs over time, as shown in FIG. As shown, the position of through hole 4 is at lands 3A and 3.
The result was that the through hole 4 was deviated from the center of B, or the through hole 4 protruded outward from the lands 3A and 3B as shown in FIG.

Incidentally, the screen used for printing the pattern tends to partially stretch as the number of times it is printed increases, and as a result, the through hole 4 gradually becomes eccentric from the land 3A13B and eventually comes off. This problem is secondary to the fact that a single screen reduces the number of prints that can be made (which means a shorter screen life), especially when fine wiring patterns have to be formed. It can also cause problems.

The present invention has been made in consideration of the above points, and is a printed circuit board that allows the drilling position of a through hole to be aligned with a predetermined position (for example, the center position of a land) with high accuracy with respect to a wiring pattern. This paper attempts to propose a method for drilling holes.

E Means for Solving the Problem In order to solve this problem, in the present invention, before drilling the through holes 4 in the printed circuit board 1, wiring patterns 2A and 2B are formed on the printed circuit board 1, and The shape and size of the wiring pattern portion 21 on the board 1 where the through hole 4 is to be drilled is detected by the wiring pattern imaging means 15, and the position P0 where the hole is to be drilled is determined based on the detection result. Drilling is performed at position P0.

After a wiring pattern is formed on the F-effect printed circuit board 1, the position to be drilled is determined based on the shape and size of the wiring pattern, so that through-holes can be drilled without misalignment with respect to the wiring pattern. can do.

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 3, reference numeral 11 denotes a printed circuit board, and a large number of processing positions P on the It is positioned at the irradiation position L, that is, the processing position.

In the case of this embodiment, the processing control device 13 is composed of a computer, and by sequentially specifying processing positions according to a machine program stored in a built-in memory, the printed circuit board driving device 12 controls the printed circuit board 11. The upper machining points P are sequentially positioned at the machining position, and each time such positioning is performed, the machining control device 13
The laser beam L drills a hole at a processing point P on the printed circuit board 11 according to a drive control signal S2 supplied from the laser beam generator 214 to the laser beam generator 214.

When the processing points P of the printed circuit board 11 are sequentially positioned at the processing positions of the laser beam L in this way, the wiring pattern at the processing point P position is imaged by the wiring pattern I imaging device 15, which is a COD camera, for example. The video signal S3 is input to the processing control device 13. Here, the printed circuit board 11 is subjected to a pattern etching process in advance before being drilled using a laser beam, so that the wiring pattern imaging device 15 can damage the wiring pattern on the printed circuit board Fill.

Thus, the processing control value W, 13 determines whether the wiring pattern to be drilled is positioned at the processing position of the laser beam L, and if the processing point P is deviated from the wiring pattern, the printed circuit board drive By correcting the position control signal S1 for the device 12, the printed circuit board driving device W12
The printed circuit board 11 is driven for correction, thereby making it possible to correctly align the processing point P with the processing position of the laser beam L.

For example, as described above with reference to FIGS. 4 and 5, when the through holes 4 are drilled in the circular lands 3A and 3B, the position of the machining point P is located at the circular land '21 as shown in FIG. center point P.

Therefore, the processing control device 13 calculates the diameter of the lead pattern portion 22 drawn out from the land 21 in the direction of a predetermined angle, and sets the center point P0 of the land 21 to the laser beam L based on the calculation result. The print base ill is corrected and controlled so that it can be aligned with the processing position.

In the case of this embodiment, the processing control value 213 is set at a center point P with an inclination of 45" clockwise and counterclockwise, respectively, with respect to the virtual straight line N1 passing through the center of the lead pattern section 22.
The diameters φA and φB of the land 21 are calculated for virtual straight lines N2 and N3 extending through , respectively, and the coordinates of the center point Pc of the diameter portions are calculated and stored in advance as the coordinates of the center point P0. The printed circuit board driving device 12 Processing point P of the printed circuit board 11 via
Align the position with the processing position of the laser beam L.

In practice, after through-holes are drilled at predetermined positions relative to the wiring pattern formed on the printed circuit board 11, the through-holes are plated as described above with reference to FIG.

In the above configuration, the processing control device 13 drills through holes on the printed circuit board 11 according to the processing program shown in FIG.

First, the CPU of the machining control device 13 enters the drilling program for the machining point in step SP1, and
Proceeding to step SP2, a virtual straight line N2 passing through the land 21 is based on the video signal S3 of the wiring pattern imaging device 15.
and calculate the diameters φA and φB for N3. Based on the calculation result data of the diameters φA and φB, the CPU of the processing control device 13 determines the coordinates of the center point P0 to be drilled in the next step SP3, and determines the diameter of the laser beam L at the processing point in the following step SP4. Determine.

In this way, the processing control device 13 can obtain data regarding the processing points based on the actual wiring pattern imaged by the wiring pattern imaging device 15, and performs a position correction operation in the subsequent step SP5 based on these processing data. Execute.

In other words, the center point P0 at which the hole should be drilled and the coordinates of the center point predetermined by the Cannibal program (the position of the printed circuit board 11 before correction is positioned at the machining point position determined by the Cannibal program). Based on the difference between Align to position P0.

Next, the CPU of the processing control device 13 moves to step SP6 and controls the laser beam generator 14 using the drive control signal S2, thereby setting the diameter of the laser beam and directing the laser beam L to the processing point P. irradiate. Thus, by irradiating the laser beam L to the center point P0 of the land 21 on the printed circuit board 11,
Drilling work will be carried out.

In this way, the CPU of the machining control device 13 moves to step SP7, finishes the drilling nib program, and then returns to the main routine.

In this way, the processing control device 13 corrects the position to be drilled in accordance with the actual wiring pattern imaged by the wiring pattern imaging device 15.
As described above with reference to FIG. 7 and FIG. 7, it is possible to prevent the through hole from shifting or coming out of the optimum position of the wiring pattern. Therefore, even if the screen shifts or stretches slightly during pattern printing, as long as the amount of shift or stretch is not extremely large, the wiring pattern can always be printed by correcting the drilling position of the through holes accordingly. Through holes can be drilled at predetermined locations.

In the above description, a case has been described in which the drilling position of the through hole is aligned with the center position of the wiring pattern, but the drilling position is not limited to this, and may be eccentric at a predetermined ratio.

In addition, in the above-mentioned embodiment, a case was described in which the drilling process was performed using a laser beam, but the same effect as in the case described above can also be obtained when other processing means, such as a drill, are used instead. can be obtained.

Furthermore, in the above embodiment, a hole with a circular cross section for electrically connecting the front side pattern and the back side pattern of the printed circuit board 1 was used as a through hole, but there are various shapes of the hole. A cross-sectional shape of can be applied. The drilled through holes may also be used for other purposes, such as holes for attaching parts.

Effects of the Invention As described above, according to the present invention, a wiring pattern is formed on a printed M board, and through holes are drilled at predetermined positions in the wiring pattern.
Even if the position of the wiring pattern is shifted, it is possible to reliably drill a through hole at a predetermined position relative to the wiring pattern.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a method for drilling holes in a printed circuit board according to the present invention, FIG. 2 is a route diagram showing an example of a method for determining the hole position for a wiring pattern, and FIG. 3 is a processing apparatus for implementing the method of the present invention. Route block diagram shown,
FIGS. 4 and 5 are a plan view and a sectional view showing the structure of a conventional through hole, and FIGS. 6 and 7 are plan views of the through hole for explaining the problems of the conventional method. ■, 11... Printed circuit board, 2A, 2B...
...Pattern, 4...Through hole, 12.
...Printed board drive device, 13...Processing control device, 14...Laser beam generator,
15...Wiring pattern side image device.

Claims (1)

[Claims] Before drilling through holes in the printed circuit board, a wiring pattern is formed on the printed circuit board, and the shape and size of the wiring pattern portion on the printed circuit board in which the through holes are to be drilled is determined by wiring. A method for drilling a hole in a printed circuit board, characterized in that the pattern is detected by a pattern imaging means, a position to be drilled is determined based on the detection result, and the hole is drilled at the determined position.