JP2003084224A - Method and device for controlling galvanoscanner, and the galvanoscanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve processing precision by improving the positioning precision of galvanoscanners while minimizing a decrease in throughput. SOLUTION: In the case of controlling galvanoscanners 14 and 16 for scanning an irradiation position of a laser beam by driving mirrors 15 and 16, patterns A and B of command values are changed according to a target irradiation position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a galvano scanner control method and device for driving a mirror to scan the irradiation position of a laser beam, and a galvano scanner,
In particular, the present invention relates to a galvano scanner control method and apparatus suitable for use in a laser drill machine that irradiates a laser beam to perform a plurality of drilling processes on a printed circuit board wiring, and a galvano scanner using the same.

[0002]

2. Description of the Related Art When a laser is used for processing, a method of moving an irradiation position by means of a galvano scanner enables high-speed processing.

FIG. 1 is a structural example of a general laser drill machine. In this configuration example, a first galvanometer scanner 14 including a mirror 15 for scanning, for example, a pulsed laser beam 12 emitted from a laser oscillator (not shown) in a predetermined direction (a direction perpendicular to the paper surface in FIG. 1). And the first
The laser beam 12 scanned by the galvano scanner 14 in the direction perpendicular to the paper surface is used for the first galvano scanner 1
Second galvano scanner 16 including a mirror 17 for scanning in a direction perpendicular to the scanning direction of 4 (direction parallel to the paper surface in FIG. 1), and the first and second galvano scanners 1
An f-θ lens 18 is provided for polarizing the laser beam scanned in two directions by 4 and 16 in a direction perpendicular to the surface of the processing object 10.

In this galvano scanner, the first and second galvano scanners 14 and 16 are used to form a laser beam 12.
Can be moved to any position on the surface of the object to be processed 10. The laser beam deflected by the mirrors 15 and 17 passes through the f-θ lens 18 and is focused on the surface of the processing object 10. For this reason, two galvo scanners 1
By controlling 4 and 16, it becomes possible to perform laser processing on an arbitrary portion of the surface of the processing object 10.

Since a high throughput is required for drilling a substrate or the like, a galvano scanner capable of performing high-speed processing by moving a laser beam is used as compared with a method of moving the object to be processed 10. Often used.

On the other hand, since a slight angle change generated in the galvano scanner is largely projected on the machined surface, the galvano scanner is required to have high positioning accuracy in order to perform the machining with high accuracy.

Generally, the driving characteristics of the galvano scanner differ depending on the operating angle. Although this difference in characteristics is slight, it cannot be ignored due to the demand for higher speed and higher accuracy.

FIG. 2 is a graph showing an error between a target machining position and an actual machining point when a hole is machined in one direction under a certain machining condition. The horizontal axis represents the distance from the starting point of the target processing position, and the vertical axis represents the error of the processing point from the target processing position. As the machining position progresses, a positive error occurs and the accuracy deteriorates. This is a phenomenon that occurs because laser irradiation is performed despite the delay in settling due to changes in the drive characteristics of the processing position.

[0009]

Conventionally, as a measure against such deterioration of processing accuracy, Japanese Patent Laid-Open No. 2000-117 has been proposed.
As proposed in 476, (1) a method of performing processing after waiting for a delay in the setting of the galvano scanner, (2) a method of slowing the driving speed of the galvano scanner to prevent the change of the setting characteristic, Alternatively, (3) measures have been taken such as reducing the processing area, but all of them have the problem of low throughput.

The present invention has been made in order to solve the above-mentioned conventional problems, and improves the positioning accuracy of the galvano scanner while minimizing the decrease in the shharput,
The task is to be able to perform processing with high accuracy.

[0011]

According to the present invention, in a galvano scanner control method for driving a mirror to scan an irradiation position of a laser beam, a pattern of a command value is changed according to a target irradiation position. Thus, the above problem is solved.

Further, the pattern of the command value to be changed is
This is the rate of change of the command value.

Further, the pattern is set for each operating direction of the mirror.

According to the present invention, in a control device of a galvano scanner for driving a mirror to scan an irradiation position of a laser beam, a means for setting a pattern of a command value for each target irradiation position and a target irradiation position. The problem is solved by providing means for selecting the pattern of the command value according to the above.

The present invention also provides a galvano scanner including the above control device.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

In the present embodiment, as shown in FIG. 3, a digital calculator 30 which calculates a command value in accordance with a target angle of the mirror 20 input from a host system (not shown) and generates a waveform of the command value. And a D / A for converting the command value output from the digital calculator 30 into an analog command voltage
Measured angle of the mirror input from the converter 32, the analog command voltage input from the D / A converter 32, and the angle sensor 24 for detecting the rotation angle of the mirror 20 driven by the motor 22. An analog circuit 34 that outputs a current command from a signal, and a power amplifier 36 that drives a motor 22 by generating a drive current according to the current command input from the analog circuit 34 are configured.

The rotation target angle of the mirror 20 is input to the digital calculator 30 from a higher-level system (not shown). The digital calculator 30 calculates a command value according to the target angle. The calculation result is the D / A converter 32.
Is input to the analog circuit 34 as an analog command voltage.

On the other hand, the angle of the mirror 20 is determined by the angle sensor 2
4 and is input to the analog circuit 34.

The analog circuit 34 outputs a current command from the command voltage and the measurement angle signal. The power amplifier 36 creates a current according to the current command, which drives the motor 22 and rotates the mirror 20.

In this way, by combining the digital calculator 30 and the analog circuit 34, it is possible to realize high-speed and high-level control. That is, high-level processing can be realized by performing feedback control that requires high-speed processing in the analog circuit 34 and generating a command value that does not matter at a relatively low speed in the digital calculator 30.

FIG. 4 shows an example of command values from the digital computer 30. The horizontal axis represents time and the vertical axis represents the command value.
According to the digital computer 30, the change rate of the command value can be changed according to the calculation method. For example, the normal command value (pattern) shown by the solid line A in FIG. 4 and the change rate shown by the alternate long and short dashed line B can be displayed. A delayed command value (pattern) can be created.

FIG. 2 shows the error of the machining point when the normal command value shown by the pattern A in FIG. 4 is used. In contrast to FIG. 2, FIG. 5 shows an example of the error of the processing point when the command pattern B shown in FIG. 4 in which the rate of change of the command value is delayed is used.
As is clear from FIG. 5, when the command pattern B is used, the error is negative at the processing position near the starting point, but the error becomes smaller as the processing position advances.

Based on such a result, in this embodiment, as shown in FIG. 6, the pattern of the command value given from the digital computer 30 to the galvano scanner is changed according to the distance from the starting point, and as shown in FIG. By using the normal command pattern A at the processing position and the pattern B at which the rate of change of the command value given to the galvano scanner is slowed at the processing position away from the start point, it is possible to perform the processing with high accuracy at any processing position. I am trying.

In determining the command pattern,
For example, it is possible to perform an experiment for measuring the machining accuracy for two or more kinds of command value change rates, and to determine the command value change rate according to the processing target position according to the experiment. The method of changing the command pattern is not limited to changing the rate of change, and the command pattern may be changed by another method, for example.

In a laser processing apparatus using a galvano scanner, the operating characteristics of the galvano scanner are non-interfering on the X axis and the Y axis.
The axis and the Y axis can be separately performed.

Further, in the above-described embodiment, the normal command pattern A and the command pattern B having a slower change rate are used, but the type and number of command patterns are not limited to this, and the change rate is, for example. It is also possible to use a command pattern that is faster. Also, depending on the characteristics of the galvano scanner, conversely, the rate of change of the command value may be slowed at the processing position where the distance from the starting point is close, or,
It is also possible to use a combination of three or more, such as pattern A → pattern B → pattern C or A.

Although the present invention has been applied to the laser drill machine in the above-described embodiments, the object to which the present invention is applied is not limited to this. For example, if a galvano scanner is used, the marking machine is, for example, a marking machine. It is obvious that other machines can be similarly applied.

[0029]

According to the present invention, it is possible to suppress the influence of the change in the settability of the galvano scanner due to the processing position, and it is possible to improve the processing accuracy.

Further, it is possible to reduce the delay of the processing time required for improving the processing accuracy. For example, in terms of processing
When the movement equivalent to mm is performed in 1 millisecond, the conventional method of processing after waiting the delay of the galvano scanner settling is
It was necessary to wait at least 0.1 milliseconds to get the effect. Further, in the case of the conventional method in which the driving speed of the galvano scanner is slowed down so that the change in the settling characteristics does not occur, it is necessary to extend the required time by at least 0.5 milliseconds to obtain the effect. On the other hand, the method according to the present invention is effective only by extending the time required to generate the command value given to the galvano scanner by 0 to 0.05 milliseconds according to the processing position.

[Brief description of drawings]

FIG. 1 is a front view showing a main configuration of a laser drill machine which is an example of an application target of the present invention.

FIG. 2 is a diagram showing an example of an error of a processing point for explaining a conventional problem.

FIG. 3 is a block diagram showing a configuration example of a galvano scanner control device according to the present invention.

FIG. 4 is a diagram showing an example of a command pattern in the embodiment of the present invention.

FIG. 5 is a diagram showing an example of a processing point error in a command pattern in which the rate of change of a command value is delayed.

FIG. 6 is a diagram showing an example of a relationship between a processing position and a command pattern.

[Explanation of symbols]

10 ... Object to be processed 12 ... Laser beam 14, 16 ... Galvano scanner 15, 17, 20 ... Mirror 22 ... Motor 24 ... Angle sensor 30 ... Digital calculator A, B ... Command pattern 32 ... D / A converter 34 ... Analog circuit 36 ... Power amplifier

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenta Tanaka             Sumitomo Heavy Industries, No. 15-15 Kyoritsutsumi, Hiratsuka City, Kanagawa Prefecture             Machine Industry Co., Ltd. Hiratsuka Office F-term (reference) 2H045 AB03 AB53 BA12                 4E068 AF00 CB01 CD11 CE03

Claims (5)

[Claims] 1. A control method of a galvano scanner for driving a mirror to scan an irradiation position of a laser beam, wherein a pattern of a command value is changed according to a target irradiation position. . 2. The control method of the galvano scanner according to claim 1, wherein the pattern of the command value to be changed is a rate of change of the command value. 3. The method of controlling a galvano scanner according to claim 1, wherein the pattern is set for each scanning direction of the mirror. 4. A control device of a galvano scanner for driving a mirror to scan an irradiation position of a laser beam, a means for setting a pattern of a command value for each target irradiation position, and a command value according to the target irradiation position. A control device for the galvano scanner, comprising: a means for selecting the pattern. 5. A galvano scanner including the control device according to claim 4.