JP4080639B2 - Laser drilling method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
According to the present invention, there is provided a means capable of controlling the irradiation position of the laser beam in a rectangular range in which the length of one side is a and the length of the other side is b. The present invention relates to a drilling method.
[0002]
[Prior art]
In a build-up type printed circuit board, a blind hole (hereinafter referred to as a hole) for connecting layers is often processed with a laser beam. Such a laser processing machine will be described with reference to FIG.
FIG. 6 is a configuration diagram of a laser processing machine that has been conventionally implemented. The pulsed laser beam 2 oscillated from the laser oscillator 1 is reflected by total reflection corner mirrors 3a and 3b whose reflecting surfaces are fixed, and as shown by arrows in the figure, can be rotated around the rotation axis and reflected. The light passes through an optical path determined by galvanometer mirrors 4a and 4b that can position the surface at an arbitrary angle, and is collected by a condenser lens 5 (fθ lens). The processing head 6 operates the galvanometer mirrors 4a and 4b to sequentially process the holes in the scan region 8. When the processing of the holes in one scan area 8 is completed, the XY table 9 is moved to perform the process in the next scan area 8. The diameter of the hole to be processed (hereinafter referred to as the hole diameter) is usually 0.3 mm or less, and the size of one scan region 8 is about 50 mm × 50 mm. The laser pulse period that can be oscillated by the laser oscillator is about 0.33 ms (frequency 3 KHz), and the pulse period TP is several tens of μs. The period TG affected by the inertia of the drive system and the natural frequency is about 2 ms, and the positioning of the table is about 200 ms.
[0003]
[Problems to be solved by the invention]
By the way, there are various types of hole diameters to be processed, and the positions where the holes are arranged are not always uniform. For this reason, simply moving the scan area in order resulted in low work efficiency and varying hole quality.
[0004]
An object of the present invention is to provide a drilling method using a laser beam that can solve the above-described problems in the prior art, improve work efficiency, and has excellent hole quality.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention uses an optical path deflecting unit that controls the irradiation position of laser light in a rectangular range in which the length of one side is a and the length of the other side is b. In the drilling method using a laser beam so as to process a circular hole whose center is defined within the range, prior to processing, the hole to be processed is classified for each hole diameter, and for each divided hole diameter In addition, the operation of arranging the range for each length a is repeated from one end of the workpiece to the other end in the X direction, and this repeating operation is repeated from one end of the workpiece to the other end in the Y direction for each length b. By arranging the range in the entire work by checking the presence or absence of the hole to be processed existing in the range arranged in each of the placement work, if the hole exists in the range, One or more of the above existing in the range X-coordinate minimum value of the X coordinate value, the minimum value of the Y coordinate and an apex point of the Y-coordinate values, the same range as the range of the square of the vertex in the X direction and the Y direction with respect of The rectangular area is set, the coordinate value of the vertex is stored, and the coordinate data of the hole included in the area is excluded from the target for determining the next area, and for each range defined by the vertex The workpiece is machined by irradiating a laser beam to the center of the hole existing in the range.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiments.
FIG. 1 is a flowchart showing a processing procedure of a drilling method according to the present invention, FIG. 2 is a flowchart showing a table moving position determination procedure for each hole diameter, and FIG. 3 is a plan view of a printed circuit board. The printed circuit board 7 has a rectangular shape with two sides of A × B. One vertex is the moving origin 0 of the table 9, one side of the length A is on the X axis, and the other side of the length B is Y. Each is positioned on an axis. The processing machine itself is the same as that shown in FIG.
[0007]
Prior to machining the workpiece, the machining program is read (step S100 in FIG. 1), and the hole diameter data to be machined described in the machining program is classified for each hole diameter (step S110). Next, the center x coordinate is rearranged for each hole diameter (step S120). In this embodiment, the x coordinates are arranged in ascending order. Then, the movement position of the table 9 is determined for each hole diameter according to the procedure of FIG. 2 to be described later (procedure S130). A movement route that minimizes the movement distance 9 is determined (step S140).
[0008]
The reason why the data is classified for each hole diameter in step S110 is as follows. That is, in order to process a hole with excellent quality, such as improving the roundness of the hole or smoothing the inner surface of the hole, it is necessary to process under appropriate conditions. However, since the appropriate conditions differ depending on the hole diameter, for example, if the output of the laser oscillator is changed, it may take time for the output to stabilize, and working with the same hole diameter together improves work efficiency. This is because there are many cases where this can be achieved.
[0009]
Further, the process of step S120 is for improving the calculation speed of table movement positioning described later, and may be omitted.
[0010]
Next, a procedure for determining the movement position of the table 9 for each hole diameter will be described with reference to FIG. The size of the scan region 8 is 50 mm × 50 mm where the two sides are equal, and if the center of the hole is within this range, it is possible to process a hole with excellent quality.
First, assuming that i = 0, j = 0, and k = 0 (procedure S200), the x coordinate is 50i ≦ x ≦ 50i + 50,
And y coordinate is 50i ≦ y ≦ 50i + 50
Whether there is a hole in the range (step S210). If there is no hole to be processed in this range, the process of step S260 is performed. If there is a hole,
k = k + 1
(Step S220), the minimum value xmin of the x coordinate is obtained,
xk = xmin (in this case x1 = xmin)
And Subsequently, the minimum value ymin of the y coordinate is obtained,
yk = ymin (in this case y1 = ymin)
(Step S230), the point Pk (in this case, P1 (x1, y1)) whose X coordinate is xk and Y coordinate is yk is stored (step S240).
[0011]
next,
xk ≦ x ≦ xk + 50
And yk ≦ y ≦ yk + 50
The coordinates of the hole in the range are removed from the data for determining the next Pk (step S250), and the process of step S260 is performed.
[0012]
In step S260, after i = i + 1, 50i is compared with A (step S270). If 50i ≧ A, the process of step S280 is performed, and if 50i <A, the process of step S210 is performed.
[0013]
In step S280, after i = 0 and j = j + 1, 50j is compared with B (step S290). If 50j ≧ B, the process of step S210 is performed, and if 50j <B, the process ends. .
[0014]
FIG. 4 is a diagram showing an example of Pk determined by the above procedure. Q1 to Q12 marked with “X” in the figure indicate the positions of the holes described in the machining program, P1 to P4 indicate the positions of the points Pk determined above, and D1 to D4 indicated by solid lines are determined by P1 to P4. S1 to S15, which indicate the scan range with dotted lines, indicate the ranges arranged in step S210, respectively. As can be seen from the figure, in the present embodiment, for example, Q6 included in S7 is included in the scan region D1, and Q7 and Q8 included in S7 and S8 are included in the scan region D2. It is not necessary to position the table at S7 and S8 for processing, and the work efficiency can be improved. In the illustrated case, the processing is performed in the order of D1, D2, D4, and D3 by the above-described procedure S140.
[0015]
FIG. 5 is a flowchart showing the procedure for determining the table movement position for each hole diameter according to the present invention. The size of the scan area 8 is 50 mm × 50 mm, the same as described above.
First, assuming that i = 0, j = 0, and k = 0 (step S300), the x coordinate is 50i ≦ x ≦ 50i + 50,
And y coordinate is 50i ≦ y ≦ 50i + 50
Whether there is a hole in the range (step S310). If there is no hole to be processed in this range, the process of step S380 is performed. If there is a hole,
k = k + 1
(Step S320), the minimum value xmin of the x coordinate is obtained,
xn = xmin
And Subsequently, the minimum value ymin of the y coordinate is obtained,
yn = ymin
(Procedure S330).
[0016]
next,
xn ≦ x ≦ xn + 50
And yn ≦ y ≦ yn + 50
The maximum value xmax of the x coordinate out of the center coordinates of the holes in the range of
xm = xmax
Then, the maximum value ymax of the y coordinate is obtained,
ym = ymax
(Procedure S340).
[0017]
next,
xk = xn- (xn + 50-xm) / 2
yk = yn- (yn + 50-ym) / 2
That is,
xk = xm + xn + 25
yk = ym + yn + 25
Xk and yk are obtained (step S350), and the point Pk (in this case, P1 (x1, y1)) whose x coordinate is xk and y coordinate is yk is stored (step S360).
[0018]
next,
xk ≦ x ≦ xk + 50
And yk ≦ y ≦ yk + 50
The coordinates of the hole in the range are removed from the data for determining the next Pk (step S370), and the process of step S380 is performed. The holes erased in step S370 are
xn ≦ x ≦ xn + 50
And yn ≦ y ≦ yn + 50
Needless to say, it matches the hole in the range of.
[0019]
In step S380, after i = i + 1, 50i is compared with A (step S390). If 50i ≧ A, the process of step S400 is performed, and if 50i <A, the process of step S310 is performed. In step S400, after i = 0 and j = j + 1, 50j is compared with B (step S410). When 50j ≧ B, the process of step S310 is performed, and when 50j <B, the process is terminated. .
[0020]
Usually, the inner surface of the hole processed at the end of the scan region 8 tends to have a lower vertical degree than the inner surface of the hole processed near the center. In this embodiment, the scan region is formed at the center of a rectangle formed by the center of the hole at both ends in the X-axis direction to be machined and the center of the hole at both ends in the Y-coordinate axis direction by steps S340 and S350. Since the center of 8 is arranged, variation in the distance between the center of the hole at the end and the center of the scan region 8 can be reduced. As a result, the perpendicularity of the inner surface of the processed hole can be improved, and the quality of the hole can be further improved.
[0021]
In the above description, the coordinates of the vertices of the scan area are determined based on the coordinates of the holes located at both ends of the X coordinate and the Y coordinate in the scan area, but in addition, in place of steps S340 and S350, Pk May be corrected so that the sum of the distances from the centers of all the holes included in the scanning region in the moving direction having Pk as the apex to the center of the scanning region is minimized.
[0022]
In any of the above cases, the point defining the scan area is the apex close to the origin of the scan area, but may be the center of the scan area, for example.
[0023]
Further, the present invention is not limited to a rectangular workpiece, and can be applied to any shape.
[0024]
【The invention's effect】
As described above, according to the present invention, it is possible to improve the work efficiency, and can also be improved hole quality.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a processing procedure of a drilling method according to the present invention.
FIG. 2 is a flowchart showing a table moving position determination procedure according to the present invention.
FIG. 3 is a plan view of a printed circuit board.
FIG. 4 is a diagram showing the results determined by the procedure of the present invention.
FIG. 5 is a flowchart showing a procedure for determining the movement position of another table of the present invention.
FIG. 6 is a configuration diagram of a conventional laser beam machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Laser oscillator 2 Laser beam 3a, 3b Total reflection corner mirror 4a, 4b Galvano mirror 5 Condensing lens 6 Processing head 7 Printed circuit board 8 Scan area 9 XY table

Claims (4)

A circular hole whose center is determined for each of the ranges by using an optical path deflecting unit that controls the irradiation position of the laser beam in a square range in which the length of one side is a and the length of the other side is b. In the drilling method using laser light,
Prior to machining, the hole to be machined is divided for each hole diameter, and the operation of arranging the range for each length a for each divided hole diameter is repeated from one end of the workpiece to the other end in the X direction. , By repeating this repeated operation from one end of the workpiece to the other end in the Y direction for each length b, the range is arranged over the entire workpiece,
Confirm the presence or absence of the hole to be processed existing in the range arranged in each of the arrangement work,
If the hole in the range exists, the minimum value of the X coordinate of one or more of the holes in the coordinate present in the range as the X coordinate value, the minimum value of the Y-coordinate point of the Y-coordinate value Is set as a vertex, a rectangular region having the same range as the rectangular region is set in the X direction and the Y direction with reference to the vertex, the coordinate value of the vertex is stored, and the holes included in the region are stored. The coordinate data is excluded from the target for determining the next region, and the workpiece is processed by irradiating the center of the hole existing in the range for each range determined by the vertex. Drilling method with laser light.   The middle coordinate of the X coordinate of the hole at both ends in the X direction included in the defined area is the center in the X direction of the range, and the Y coordinate of the hole at both ends in the Y direction included in the defined area 2. The drilling method using laser light according to claim 1, wherein the region is moved so that the intermediate coordinates of the region coincide with the center of the range in the Y direction.   The defined region is moved so that the sum of the distances from the centers of all the holes included in the defined region to the center of the defined region is minimized. Drilling method by laser beam.   4. A drilling method using a laser beam according to claim 1, wherein when there are three or more defined areas, the shortest path connecting them is obtained.

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