JP3850308B2 - Method and apparatus for digital control of galvano scanner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital control method and apparatus for a galvano scanner for moving a beam irradiation position using a plurality of mirrors that operate independently from each other , and more particularly, a laser beam is applied to a printed wiring board or the like. The present invention relates to a digital control method and apparatus for a galvano scanner suitable for use in a laser drill machine that performs drilling at an appropriate position and capable of reducing the processing time.
[0002]
[Prior art]
A configuration example of a main part of a general laser drill machine is shown in FIG. In this configuration example, for example, a pulsed laser beam 12 irradiated from a laser oscillator (not shown) is applied to a predetermined Y direction (a direction perpendicular to the paper surface in FIG. 1) on the surface (processed surface) 10A of the processing target 10. A first galvano scanner 14 including a mirror (referred to as a Y mirror) 15 for scanning, and a laser beam 12 scanned in the Y direction by the first galvano scanner 14 are similarly processed on the processing surface 10A by the first galvano scanner 14. A second galvano scanner 16 including a mirror (referred to as an X mirror) 17 for scanning in the X direction (direction parallel to the paper surface in FIG. 1) perpendicular to the scanning direction by the first and second galvano scanners 14, And an f-θ lens 18 for deflecting the laser beam scanned in two directions by 16 in a direction perpendicular to the processing surface 10A.
[0003]
In this galvano scanner, the laser beam 12 can be moved to an arbitrary position in the processing surface 10A by rotating the mirrors 15 and 17 with the first and second galvano scanners 14 and 16. When the laser beams deflected by the mirrors 15 and 17 pass through the f-θ lens 18, they are condensed on the processing surface 10 </ b> A. For this reason, by controlling the two galvano scanners 14 and 16, it is possible to perform laser processing on an arbitrary portion of the processing surface 10A.
[0004]
Although FIG. 1 illustrates the case where there are two galvano scanners, there may be three or more.
[0005]
Since a high throughput is required for drilling a substrate, etc., a galvano scanner that can perform processing at high speed by moving the laser beam is used compared to the method of moving the workpiece 10. There are many.
[0006]
[Problems to be solved by the invention]
In general, however, the galvano scanner differs depending on the size and amount of movement of the mirror. After reaching the target angle, the time required for positioning until the vibration is settled and the laser beam can be irradiated differs. The longer the positioning takes. Further, the positioning characteristics may differ depending not only on the movement amount but also on the absolute movement position.
[0007]
In order to reach a certain processing point, it is necessary to position the plurality of galvano scanners, and it is meaningless to position only one of them quickly.
[0008]
When command values are output to a plurality of galvano scanners, there may be a time difference in output depending on the system configuration. The influence on the completion of positioning when such a time difference occurs will be described with reference to FIG. 2, taking an example of two galvano scanners. As shown in FIG. 2A, when the X mirror 17 is always driven with priority (referred to as X priority), the movement direction in the X direction is long under the condition (a) in which the movement time in the Y direction is long. Compared with the condition (A), the completion of positioning to the machining point is delayed by the time difference of the command value output. On the other hand, as shown in FIG. 2B, when the Y mirror 15 is always driven with priority (referred to as Y priority), this phenomenon occurs under the condition (i) in which the movement time in the X direction becomes longer. appear. Even if this time difference is small, it has become impossible to ignore in accordance with the demand for higher speed.
[0009]
Conventionally, either (1) the larger mirror (X mirror 17 in the example of FIG. 1) is always driven first, or (2) the smaller mirror (Y in the example of FIG. 1). Measures such as always driving the mirror 15) first and increasing the number of movements of the Y mirror on the machining path have been taken, but all of them can only reduce the problem and are not necessarily optimal. I couldn't.
[0010]
The present invention has been made to solve the above-described conventional problems, and minimizes a decrease in throughput by performing determination / operation for each movement without fixing the order of command value output to a plurality of galvano scanners. The problem is to keep it at a minimum.
[0011]
[Means for Solving the Problems]
The present invention relates to a digital control method of a galvano scanner for moving a beam irradiation position using a plurality of mirrors operating independently from each other, and does not fix the output order of command values, and the time required for positioning of each mirror And the command value is output in order from the one that takes time for positioning, thereby solving the above-mentioned problem.
[0012]
The time required for the positioning is predicted based on the relationship between the movement amount of each mirror and the movement time obtained in advance by experiments.
[0013]
Further, the time required for the positioning is obtained by multiplying the moving amount of each mirror by a coefficient obtained for each mirror.
[0014]
Alternatively, the time required for the positioning is obtained using a table prepared for each mirror.
[0015]
The present invention also provides a beam irradiation position control method characterized in that the beam irradiation position is controlled using the digital control method of the galvano scanner.
[0016]
The present invention also provides means for predicting the time required for positioning of each mirror in a digital control device for a galvano scanner for moving a beam irradiation position using a plurality of mirrors operating independently from each other, and a command value The output order is not fixed, and means for outputting command values in order from the one that takes time for positioning is provided to solve the above-mentioned problem.
[0017]
The present invention also provides a beam irradiation position control device comprising the digital control device for the galvana scanner.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the embodiment of the present invention will be described in detail by taking the case of two galvano scanners as an example.
[0019]
As shown in FIG. 3, the galvano scanner control device according to the present invention and its peripheral device are digital units that generate a command value 320 for each mirror in accordance with a target angle 200 for each mirror input from the host controller 20. Triggered by a calculator 32, a D / A converter 34 that converts the command value 320 output from the digital calculator 32 into an analog command voltage 340, and a movement start command 202 from the host controller 20 The analog command voltage 340 input from the / A converter 34 and the angle sensor 42 provided for each mirror for detecting the rotation angle of the mirror driven by the motor 40 provided for each mirror are input. The analog circuit 36 that outputs a current command 360 for each mirror from the mirror angle measurement signal 420, and the analog circuit 36 That current creates a driving current 380 in response to a command 360, for driving the motor 40 is configured to include a power amplifier 38 provided for each mirror.
[0020]
Here, a portion surrounded by a broken line is the galvano scanner control device 30.
[0021]
In the figure, reference numeral 50 denotes a laser oscillator that oscillates a laser beam in response to a trigger signal 204 input from the host controller 20.
[0022]
In the present embodiment, the target angle 200 of the two mirrors 14 and 16 is input from the host controller 20 to the digital calculator 32, and a command value 320 is generated. This is converted into an analog command voltage 340 by the D / A converter 34 and input to the analog circuit 36 using the movement start command 202 from the host controller 20 as a trigger.
[0023]
On the other hand, the angle 420 of the mirrors 14 and 16 is measured by the angle sensor 42 and input to the analog circuit 36.
[0024]
In the analog circuit 36, feedback control is incorporated, and a current command 360 is output from the command voltage 340 and the measurement angle signal 420.
[0025]
A drive current 380 in accordance with the current command 360 is generated for each mirror by the power amplifier 38, whereby the motor 40 is driven and the mirrors 14 and 16 are rotated.
[0026]
The analog circuit 36 further generates a set-in-range signal 362 indicating that the motor angle is within a preset set-up range for each mirror. The generation of the signal within the settling range is described in detail in Japanese Patent Application Laid-Open No. 2003-236692 previously filed by the applicant, and thus the description thereof is omitted.
[0027]
The set-in-range signal 362 is input to the digital calculator 32, and a positioning completion determination is made based on the signal, and a positioning completion signal 322 is output to the host controller 20.
[0028]
Receiving this, the host controller 20 outputs a trigger signal 204 to the laser oscillator 50, and the laser is irradiated.
[0029]
The output order of the command value 320 to the two galvano scanners according to the present invention is determined by the digital calculator 32.
[0030]
Hereinafter, in order to make the explanation easy to understand, details in the case of two galvano scanners will be specifically described.
[0031]
In order to determine which galvano scanner the command value is to be output first, the relationship between the movement amount and the movement time in each galvano scanner is clarified in advance by experiments or the like. Hereinafter, an example of a method for determining based on this relationship will be described.
[0032]
First, as shown in FIG. 4, regardless of the amount of movement, if the ratio of the X and Y galvano scanner movement times is almost the same, the ratio of the X movement time and the Y movement time is determined one. can do. These are set as Tx and Ty and stored in the digital calculator 32.
[0033]
The output order of the command values in such a case is determined according to a procedure as shown in FIG. That is, in the operation, first, when the target value is input, the movement amount of X and Y is calculated in step 100. Next, the relative movement times are calculated by multiplying the movement times of X and Y by the preset coefficients Tx and Ty, respectively.
[0034]
Next, in step 102, these are compared, and in step 104 or 106, the command value is first output to the galvano scanner having the longer movement time.
[0035]
On the other hand, as shown in FIG. 6, in the second case where the ratio of the movement time of X and Y varies depending on the movement amount, the movement time is approximated for each movement amount range. At this time, the movement amount range is narrow where the change in the movement time is large, and is broadly divided where the movement time is small. The narrower the movement amount range, the more accurately the movement time can be obtained.
[0036]
The obtained travel time is stored in the digital calculator 32 as a travel time table as shown in FIG.
[0037]
The output order of the command values in such a case is determined according to a procedure as shown in FIG.
[0038]
That is, in the operation, first, when the target value is input, the movement amount of X and Y is calculated in step 100.
[0039]
Next, in step 202, the X and Y movement times corresponding to the movement amount are read from a preset movement time table and approximated for each movement amount range.
[0040]
Next, in step 204, these are compared, and in step 206 or 208, the command value is first output to the galvano scanner having the longer movement time.
[0041]
By such a method, the command value output order is not fixed, and the command value to the galvano scanner under conditions that require time for positioning is determined / operated for each movement so that the command value is output first. 2) Avoiding a decrease in positioning time as shown in FIGS. 2B and 2A, it is possible to always operate without waste as shown in FIGS. 2A, 2B and 2A. It becomes.
[0042]
In the above embodiment, the number of galvano scanners is two for the sake of simplicity. However, the number of galvano scanners is not limited to this, and three or more, for example, two holes are simultaneously punched. In order to perform processing, it is apparent that the present invention can be similarly applied to a laser drill machine in which two optical systems as shown in FIG. 1 are arranged in parallel and there are 2 × 2 = 4 galvano scanners. In this case, the command value can be output in order from the longest movement time.
[0043]
Moreover, in the said embodiment, although this invention was applied to the laser drill machine, application of this invention is not limited to this, For example, if a galvano scanner is used, other machines, such as a marking machine, are used. Obviously, the same applies to machines. The type of beam is not limited to a laser beam.
[0044]
【The invention's effect】
According to the present invention, command values can be output to a plurality of galvano scanners in an appropriate output order in consideration of the time required for movement, and a reduction in throughput can be minimized.
[0045]
Therefore, for example, when used in a laser drill machine, the drilling time can be shortened.
[Brief description of the drawings]
FIG. 1 is a front view showing a configuration of a main part of a laser drill machine to which the present invention is applied. FIG. 2 is a time chart showing the influence of positioning completion in the order of command value output for explaining conventional problems. FIG. 3 is a block diagram showing a configuration of an embodiment of a galvano scanner control device and peripheral devices according to the present invention. FIG. 4 is a diagram showing an example of a relationship between a moving amount of a mirror and a moving time. FIG. 6 is a diagram showing another example of the relationship between the amount of movement of the mirror and the time of movement. FIG. 7 is used for the example of FIG. FIG. 8 is a flowchart showing an example of a procedure for determining the order of command value output.
DESCRIPTION OF SYMBOLS 10 ... Processing object 10A ... Processing surface 12 ... Laser beam 14, 16 ... Galvano scanner 15, 17 ... Mirror 18 ... f-theta lens 20 ... Host controller 30 ... Galvano scanner control device 32 ... Digital calculator 34 ... D / A Converter 36 ... Analog circuit 38 ... Power amplifier 40 ... Motor / mirror 42 ... Angle sensor 50 ... Laser oscillator 200 ... Mirror target angle 202 ... Movement start command 204 ... Trigger signal 320 ... Mirror command value 322 ... Positioning completion signal 340 ... Analog Command voltage 360 ... Current command 362 ... Settling range signal 380 ... Drive current 420 ... Mirror angle measurement signal

Claims (7)

In a digital control method of a galvano scanner for moving a beam irradiation position using a plurality of mirrors operating independently of each other,
The order of command value output is not fixed,
Predict the time required to position each mirror,
A digital control method for a galvano scanner, characterized in that command values are output in order from the one that takes time for positioning. The galvano scanner digital control method according to claim 1, wherein the time required for the positioning is predicted based on a relationship between a movement amount and a movement time of each mirror obtained in advance by an experiment. 3. The digital control method for a galvano scanner according to claim 2, wherein the time required for the positioning is obtained by multiplying the moving amount of each mirror by a coefficient obtained for each mirror. 3. The digital control method for a galvano scanner according to claim 2, wherein the time required for the positioning is obtained by using a table prepared for each mirror. A beam irradiation position control method, comprising: controlling a beam irradiation position using the digital control method for a galvano scanner according to claim 1. In a digital control device of a galvano scanner for moving a beam irradiation position using a plurality of mirrors operating independently of each other,
Means for predicting the time required to position each mirror;
Means for outputting the command values in order from the one that takes time for positioning without fixing the output order of the command values;
A digital control device for a galvano scanner, comprising: A beam irradiation position control device comprising the digital control device for a galvano scanner according to claim 6.

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