JP7043128B2 - Laser control device and laser processing method - Google Patents

Description

The present invention relates to a laser control device and a laser processing method.

A laser processing technique is known in which a laser beam is incident on a substrate on which a metal film is arranged on the upper surface and the bottom surface of the resin layer to make a hole in the metal film on the upper surface and the resin layer (Patent Document 1). In the laser processing disclosed in Patent Document 1, a portion of one laser pulse output from the laser oscillator having a relatively high light intensity is cut out and a hole is formed in the metal film on the upper surface, and after attenuation is started. A portion with low light intensity is cut out and a hole is drilled in the resin layer. In this way, the processing of processing the next work point after the drilling of one work point is completed is called burst processing.

For burst machining, one cycle is a procedure in which a pulsed laser beam is sequentially incident on a plurality of machining points of a machining object one shot at a time, and a plurality of cycles are repeated for a plurality of common machining points. Is called cycle processing. In cycle processing, since the time interval between a plurality of laser pulses incident on one processing point becomes long, there is an advantage that the heat storage due to the incident of the laser pulses is not easily affected.

In the cycle processing, the metal film is drilled in the first cycle, and the resin film is drilled in the second and subsequent cycles. The total number of cycles is determined by the required specifications of processing quality, the thickness of the resin film, and the like.

Japanese Unexamined Patent Publication No. 2017-47471

In machining using a pulsed laser beam, the optimum pulse energy for machining is selected. The pulse energy when drilling a hole in a metal film is larger than the pulse energy when drilling a hole in a resin film. When cycle processing is performed, the pulse energy of the first cycle becomes larger than the pulse energy of the second and subsequent cycles. Generally, the pulse energy is adjusted by changing the pulse width.

During laser machining, feedback control is performed on the laser oscillator so that the pulse energy is maintained at the target value. However, when cycle processing is performed, the target value of pulse energy changes for each cycle. For this reason, conventionally, feedback control has not been performed during cycle machining.

An object of the present invention is to provide a laser control device capable of performing feedback control so that pulse energy is maintained at a target value even during cycle processing. Another object of the present invention is to provide a laser machining method capable of performing cycle machining while performing feedback control so that pulse energy is maintained at a target value.

According to one aspect of the invention
One cycle is a procedure in which a pulsed laser beam is output from a laser oscillator having a discharge electrode for exciting a laser medium, and the pulsed laser beam is sequentially incident on a plurality of work points of a workpiece one shot at a time. It is a laser control device incorporated in a laser processing device that repeats a plurality of cycles for a plurality of the machined points to perform laser processing.
Feedback that changes the discharge voltage applied to the discharge electrode so that the energy measurement value, which is the measurement value of the pulse energy of the pulse laser beam, is maintained at the energy target value, which is the target value of the pulse energy set for each cycle. A laser control device for controlling is provided.

According to another aspect of the invention
It is a method of performing laser machining by repeating a plurality of cycles for a plurality of the workpieces, with the procedure of injecting a pulsed laser beam one shot at a time into a plurality of workpieces of an object to be machined in order as one cycle. hand,
For a laser oscillator that has a discharge electrode for exciting a laser medium and outputs a pulsed laser beam, the discharge electrode has a pulse energy maintained at an energy target value, which is a target value of the pulse energy . A laser processing method is provided in which different values are used as the energy target values in at least two different cycles when a plurality of cycles are executed while performing feedback control for changing the applied discharge voltage .

Since the target value of the pulse energy is set for each cycle, feedback control can be performed even if the target value of the pulse energy is different for each cycle.

FIG. 1 is a schematic view of a laser processing device incorporating a laser control device according to an embodiment. 2A and 2B are a plan view and a cross-sectional view of the object to be machined, respectively, and the views on the left side of FIGS. 2C to 2E show the machining order of the machined points in the 1st to 3rd cycles in one block, respectively. It is a plan view shown, and the figure on the right side is a cross-sectional view of one work point at the end of the first to third cycles, respectively. FIG. 3 is a block diagram of the laser control device according to the present embodiment. FIG. 4 is a chart showing an example of oscillation condition parameters. FIG. 5 is a graph showing the relationship between the deviation (energy deviation) from the energy target value Er to the energy measurement value Em and the amount of increase / decrease in the voltage command value Vc. FIG. 6 is a flowchart of processing performed by the laser control device. FIG. 7 is an example of time changes of the oscillation command signal S0, the cycle designation signal S3, the energy target value Er, the energy measurement value Em, and the feedback gain G when processing with the laser processing device equipped with the laser control device according to the embodiment. It is a graph which shows. FIG. 8 shows an example of time changes of the oscillation command signal S0, the cycle designation signal S3, the energy target value Er, the energy measurement value Em, and the feedback gain G when processing with a laser processing device equipped with a laser control device according to a modification. It is a graph which shows.

A laser control device and a laser processing method according to an embodiment will be described with reference to FIGS. 1 to 7.
FIG. 1 is a schematic view of a laser processing device incorporating a laser control device according to an embodiment. The laser oscillator 10 receives control from the laser control device 30 and outputs a pulsed laser beam. As the laser oscillator 10, a laser oscillator that outputs a pulsed laser beam, for example, a gas laser oscillator such as a carbon dioxide laser oscillator can be used. The laser oscillator 10 includes a laser medium gas, a discharge electrode for excitation, a power source for supplying high frequency power to the discharge electrode, and the like.

The pulsed laser beam output from the laser oscillator 10 passes through the optical system 11 including the beam expander, is reflected by the bending mirror 12, passes through the aperture 13, and is incident on the branched optical system 15. The branching optical system 15 branches the incident pulsed laser beam into two paths. As the branched optical system 15, a half mirror, a polarizing beam splitter, an acoustic optical element (AOM), or the like can be used.

The pulsed laser beam branched by the branched optical system 15 and propagating in one path is incident on the workpiece 20A via the beam scanner 16A and the lens 17A. The pulsed laser beam propagating in the other path enters the workpiece 20B via the beam scanner 16B and the lens 17B. The beam scanners 16A and 16B include, for example, a pair of galvano mirrors and have a function of scanning a pulsed laser beam in a two-dimensional direction. The lenses 17A and 17B focus the pulsed laser beam on the surfaces of the workpieces 20A and 20B, respectively. It should be noted that the aperture 13 may be configured to form an image on the surfaces of the objects to be processed 20A and 20B.

The objects to be processed 20A and 20B are, for example, printed wiring boards, and are held on the holding surface of the stage 18. Drilling is performed by injecting a pulsed laser beam onto the printed wiring board. The holding surface of the stage 18 is, for example, horizontal. The stage 18 can move the objects to be processed 20A and 20B in two directions in the horizontal plane. As the stage 18, for example, an XY stage can be used.

A part of the pulsed laser beam incident on the bending mirror 12 passes through the bending mirror 12 and is incident on the photodetector 19. The photodetector 19 outputs an electric signal (detection signal S1) corresponding to the light intensity of the incident pulsed laser beam. As the photodetector 19, an infrared sensor having a response speed capable of following a change in a laser pulse waveform, for example, an MCT sensor or the like can be used. The detection signal S1 is input to the laser control device 30.

The host control device 40 controls the beam scanners 16A, 16B, and the stage 18. Further, the host control device 40 transmits an oscillation command signal S0 that commands the laser control device 30 to start and stop the output of the laser pulse. The laser control device 30 starts the excitation of the laser oscillator 10 when the host control device 40 commands the start of output of the laser pulse, and stops the excitation of the laser oscillator 10 when the output stop is commanded.

FIG. 2A is a plan view of the object to be machined 20. The surface of the object to be machined 20 is divided into a plurality of blocks 21, and a plurality of work points 22 are defined in each of the blocks 21. Each of the blocks 21 is smaller than the range in which the pulsed laser beam can be scanned by the beam scanners 16A and 16B. Therefore, by driving the beam scanners 16A and 16B without moving the object to be machined 20 on the stage 18, the machining in one block 21 can be performed.

FIG. 2B is a cross-sectional view of the object to be machined 20. Metal films 24 and 25 are attached to the upper surface and the lower surface of the resin layer 23, respectively. For example, copper foil is used for the metal films 24 and 25. In this embodiment, a pulsed laser beam is incident on the workpiece 22 (FIG. 2A) of the object to be machined 20 to make a hole in the metal film 24 and the resin layer 23 on the upper surface, and the metal on the lower surface is formed in the bottom of the hole. Processing is performed to expose the film 25.

In this embodiment, cycle processing is applied. One cycle is a procedure in which a pulsed laser beam is output from a laser oscillator 10 (FIG. 1) and a pulsed laser beam is sequentially incident on all processed points 22 (FIG. 2A) in one block 21 one shot at a time. do. By repeating a plurality of cycles for a plurality of workpiece points 22, a plurality of laser pulses are incident on all the workpiece points 22 in one block 21 to perform drilling. The plurality of work points 22 to which the pulsed laser beam is incident in each cycle are common. That is, the plurality of workpiece points 22 to which the pulsed laser beam is incident in each cycle after the second cycle are the same as the plurality of workpiece points 22 to which the pulsed laser beam is incident in the first cycle. The order of the processed points 22 to which the pulsed laser beam is incident does not necessarily have to be the same between the cycles.

Next, a procedure for drilling a hole in the object to be machined 20 will be described with reference to FIGS. 2C to 2E. The figure on the left side of FIG. 2C is a plan view showing the processing order of the machined points 22 in the first cycle in one block 21, and the figure on the right side is one machined point when the first cycle is completed. 22 is a cross-sectional view of 22. 2D and 2E are similar plan views and cross-sectional views in the second cycle and the third cycle, respectively.

As shown in the figures on the left side of FIGS. 2C to 2E, a plurality of work points 22 are defined on the surface of the block 21. In any of the first cycle, the second cycle, and the third cycle, the machining order of the plurality of workpiece points 22 is the same.

As shown in the figure on the right side of FIG. 2C, the hole 29 is formed by the laser pulse 26 incident on the work point 22 in the first cycle. The width of the figure representing the laser pulse 26 corresponds to the beam size, and the area corresponds to the pulse energy. The hole 29 formed in the first cycle penetrates the metal film 24 on the upper surface and reaches halfway in the thickness direction of the resin layer 23, but does not reach the metal film 25 on the lower surface.

As shown in the figure on the right side of FIG. 2D, the laser pulse 27 is incident on the work point 22 in the second cycle, and the hole 29 becomes deep. As shown in the figure on the right side of FIG. 2E, the laser pulse 28 is incident on the work point 22 in the third cycle, and the hole 29 reaches the metal film 25 on the lower surface. Laser machining is completed in 3 cycles. The pulse energy of the laser pulse 27 in the second cycle and the laser pulse 28 in the third cycle is smaller than the pulse energy of the laser pulse 26 in the first cycle.

FIG. 3 is a block diagram of the laser control device 30 according to the present embodiment. The laser control device 30 includes a drive signal transmission unit 31, a feedback control unit 32, a parameter setting unit 33, a cycle designation information setting unit 34, and a pulse energy calculation unit 35. The functions of each of these parts are realized, for example, by a computer executing an application program.

The drive signal transmission unit 31 receives the oscillation command signal S0 commanding the start and stop of oscillation from the host control device 40, and transmits the drive signal S2 to the laser oscillator 10 based on the oscillation command signal S0. For example, the rising and falling edges of the oscillation command signal S0 mean commands for starting and stopping oscillation, respectively. When the drive signal transmission unit 31 receives a command to start oscillation, it starts transmitting the drive signal S2 to the laser oscillator 10, and when it receives a command to stop oscillation, it stops transmitting the drive signal S2 to the laser oscillator 10. .. The laser oscillator 10 applies a high-frequency discharge voltage to the discharge electrode during the period in which the drive signal S2 is received from the drive signal transmission unit 31. When the discharge voltage is applied to the discharge electrode, a laser pulse is output from the laser oscillator 10.

The parameter setting unit 33 receives the oscillation condition parameter setting signal S4 from the host control device 40 and stores the oscillation condition parameter.

FIG. 4 is a chart showing an example of oscillation condition parameters. The oscillation condition parameters include an energy target value Er, a voltage initial value Vo, and a feedback gain G. These oscillation condition parameters are set for each cycle. For example, the information that specifies the nth cycle is represented by the cycle number n. The oscillation condition parameter is used in the feedback control executed by the feedback control unit 32.

The cycle designation information setting unit 34 shown in FIG. 3 acquires a cycle designation signal S3 that designates one cycle from the first cycle to the third cycle from the host control device 40, and is designated by the cycle designation signal S3. Cycle designation information Cy, for example, a cycle number is stored. The host control device 40 transmits a cycle designation signal S3 that specifies the currently executing cycle to the cycle designation information setting unit 34.

The pulse energy calculation unit 35 receives the detection signal S1 from the photodetector 19, and calculates the pulse energy based on the detection signal S1. For example, the pulse energy is calculated by integrating the pulse waveform of the detection signal S1. Further, the energy measurement value Em is obtained by averaging the calculated values of the pulse energy over a plurality of laser pulses.

The feedback control unit 32 performs feedback control to the laser oscillator 10 so that the energy measurement value Em obtained by the pulse energy calculation unit 35 is maintained at the energy target value Er stored in the parameter setting unit 33. conduct. For example, the voltage command value Vc given to the laser oscillator 10 is increased or decreased based on the deviation from the energy target value Er to the energy measurement value Em and the feedback gain G. The laser oscillator 10 applies a voltage commanded by the voltage command value Vc to the discharge electrode to perform pulse laser oscillation.

When performing this feedback control, the feedback control unit 32 uses the energy target value Er and the feedback gain G corresponding to the cycle currently being executed. The currently executing cycle can be specified based on the cycle designation information Cy stored in the cycle designation information setting unit 34.

Next, the feedback control performed by the feedback control unit 32 will be described with reference to FIG.

FIG. 5 is a graph showing the relationship between the deviation (energy deviation) from the energy target value Er to the energy measurement value Em and the amount of increase / decrease in the voltage command value Vc. The relationship between the energy deviation and the amount of increase / decrease in the voltage command value Vc is defined for each feedback gain G. If the deviation is 0 regardless of the feedback gain G, the amount of increase / decrease in the voltage command value Vc is 0. When the energy measurement value Em is equal to or greater than the energy target value Er (when the energy deviation is positive), the voltage command value Vc is lowered as the energy deviation increases. When the energy measurement value Em is equal to or less than the energy target value Er (when the energy deviation is negative), the voltage command value Vc is increased as the absolute value of the deviation increases. The feedback gain G is the ratio of the increase / decrease amount of the voltage command value Vc to the energy deviation (slope of the graph in FIG. 5). The larger the feedback gain G, the larger the slope of the graph in the negative direction.

The feedback control unit 32 determines the amount of increase / decrease in the voltage command value Vc based on the relationship between the energy deviation shown in FIG. 5 and the amount of increase / decrease in the voltage command value Vc. The feedback control to the voltage command value Vc is executed, for example, every predetermined number of shots (for example, every 1000 shots) during the processing period of one block 21 (FIG. 2A).

FIG. 6 is a flowchart of laser processing using a laser processing device equipped with a laser control device 30. First, the laser control device 30 receives the oscillation condition parameter setting signal S4 (FIG. 3) from the host control device 40 and stores the oscillation condition parameter (FIG. 4) (step ST0). Further, the laser control device 30 receives the cycle designation signal S3 from the host control device 40. Initially, the cycle number 1 is designated by the cycle designation signal S3, and the cycle number is initially set (step ST1).

The feedback control unit 32 of the laser control device 30 acquires the cycle designation information Cy from the cycle designation information setting unit 34. Further, the energy target value Er and the feedback gain G (FIG. 4) of the cycle designated by the cycle designation information Cy are acquired from the parameter setting unit 33 (step ST2).

The laser control device 30 updates the feedback gain G based on the measurement result of the laser energy during the same cycle execution of the block 21 (FIG. 2A) processed immediately before (step ST3). When the block 21 to be machined is the first block, the value acquired from the parameter setting unit 33 is used as the feedback gain G. For example, when the energy measurement value Em of the same cycle of the block 21 processed immediately before is too large with respect to the energy target value, the feedback gain G may be updated in the direction of reducing the feedback gain G. In this way, the feedback gain G may be increased or decreased based on the difference between the measured energy value Em and the energy target value.

One cycle of machining is executed while periodically updating the voltage command value Vc (every predetermined number of shots) so that the energy measurement value Em is maintained at the energy target value Er (step ST4). As the initial value of the voltage command value Vc, the voltage initial value Vo (FIG. 4) stored in the parameter setting unit 33 is used.

The cycle number is updated (step ST6) until the processing of one block 21 (FIG. 2A) is completed, and the processing from step ST2 to step ST4 is repeated (step ST5). The host control device 40 determines whether or not the processing of one block is completed. The cycle number is updated by the host control device 40 transmitting the cycle designation signal S3 to the cycle designation information setting unit 34 of the laser control device 30.

When the processing of one block 21 is completed, it is determined whether or not the processing of all the blocks 21 is completed (syTep ST7). This determination is executed by the host control device 40. When the unprocessed block 21 remains, the host control device 40 moves the block 21 to be processed next within the laser scannable range (step ST8), and initializes the cycle number (step ST9). After that, the processes from step ST2 to step ST5 are repeated. When the processing of all the blocks 21 is completed, the laser processing for the object to be processed 20 is completed.

FIG. 7 is a graph showing an example of time changes of the oscillation command signal S0, the cycle designation signal S3, the energy target value Er, the energy measurement value Em, and the feedback gain G. One block 21 (FIG. 2A) is processed during the period from time t0 to t5, and the next block 21 is processed during the period from time t6 to t11. The first cycle of machining is performed during the period from time t0 to t1 and from time t6 to t7, and the second cycle of machining is performed during the period from time t2 to t3 and from time t8 to t9. The third cycle of machining is performed during the period from time t4 to t5 and from time t10 to t11.

During the processing period of the first cycle, the cycle designation signal S3 for designating the first cycle is transmitted from the host control device 40 to the laser control device 30. During the processing period of the second cycle, the cycle designation signal S3 for designating the second cycle is transmitted from the upper control device 40 to the laser control device 30. During the processing period of the third cycle, the cycle designation signal S3 for designating the third cycle is transmitted from the host control device 40 to the laser control device 30.

During the machining period of the first cycle, the energy target value Er and the feedback gain G are set to the energy target value Er (1) and the feedback gain G (1) of the first cycle, respectively. During the machining period of the second cycle, the energy target value Er and the feedback gain G are set to the energy target value Er (2) and the feedback gain G (2) of the second cycle, respectively. During the machining period of the third cycle, the energy target value Er and the feedback gain G are set to the energy target value Er (3) and the feedback gain G (3) of the third cycle, respectively.

In each cycle, processing is performed while periodically updating the voltage command value Vc based on the deviation between the energy measurement value Em and the energy target value Er (step ST4 in FIG. 6).

When machining the first cycle from time t6 to t7, the energy measurement value Em (from time t0 to t1) of the same cycle of the block 21 machined immediately before is fed back to the feedback gain G. Similarly, when processing the second cycle from time t8 to t9 and the third cycle from time t10 to t11, the energy measurement value Em from time t2 to t3 and the energy measurement from time t4 to t5, respectively. The value Em is fed back to the feedback gain G. For example, the feedback gain G is increased or decreased based on the magnitude of the fluctuation of the energy measurement value Em.

Next, the excellent effect obtained by mounting the laser control device 30 (FIGS. 1 and 3) on the laser processing apparatus according to the above embodiment will be described.

In the above embodiment, a different energy target value Er (FIG. 4) can be set for each cycle. Further, the cycle designation signal S3 notifies the laser control device 30 from the host control device 40 of the cycle number of the machining currently being executed. Therefore, even if the target pulse energy is different for each cycle, the laser control device 30 can perform feedback control so as to maintain the energy measurement value Em at the energy target value Er.

In particular, in a gas laser such as a carbon dioxide gas laser, changing the pulse width changes the gas temperature in the chamber, so in order to obtain a stable output, it is necessary to change the discharge voltage and feedback gain G according to the pulse width. desirable. In the above embodiment, the initial voltage value Vo and the feedback gain G (FIG. 4) are set for each cycle, so that a stable output can be obtained.

When executing a certain cycle of one block, it is fed back to the feedback gain G of the next cycle to be machined based on the energy measurement value Em of the same cycle of the block 21 machined immediately before, not to the cycle immediately before. For example, in the example shown in FIG. 7, the measurement result in the cycle three times before is fed back to the machining of the cycle from the time t6 to t7. In this way, by feeding back the measurement results of the same cycle, appropriate feedback control can be performed.

Next, various modifications of the above embodiment will be described.
In the above embodiment, three cycles are executed for machining one block 21 (FIG. 2A), but the number of cycles may be other. For example, the metal film 24 (FIG. 2B) on the upper surface may be penetrated in the first cycle, and one cycle or three or more cycles may be executed for processing the resin layer 23 (FIG. 2B). In a plurality of cycles after the second cycle, the energy target value Er may be the same or different. For example, in order to reduce damage to the metal film 25 (FIG. 2B) on the lower surface, the energy target value Er of the cycle executed later may be smaller than the energy target value Er of the cycle executed earlier.

Further, in the above embodiment, since the oscillation condition parameter for each cycle is stored in the laser control device 30, it is not necessary for the host control device 40 to notify the laser control device 30 of the oscillation condition parameter every time the cycle is switched. When the cycle is switched, the upper control device 40 may notify the laser control device 30 of the cycle number. Therefore, it is possible to speed up the cycle switching process.

When the time required for transferring various information between the upper control device 40 and the laser control device 30 is sufficiently short, the oscillation condition parameter is transmitted from the upper control device 40 to the laser control device 30 at each cycle change. You may try to do it.

In the above embodiment, the printed wiring board is drilled, but the laser control device 30 (FIG. 1) according to the embodiment can be applied to a laser machining device that performs cycle machining using a pulse laser. ..

Next, another modification will be described with reference to FIG.
FIG. 8 shows the oscillation command signal S0, the cycle designation signal S3, the energy target value Er, the energy measurement value Em, and the feedback gain G time when processing is performed by the laser processing device equipped with the laser control device 30 according to this modification. It is a graph which shows an example of a change.

In the embodiment shown in FIG. 7, the measurement result of the same cycle of the block 21 (FIG. 2A) processed immediately before was fed back to the feedback gain G. On the other hand, in the modification shown in FIG. 8, in the processing of the first cycle, the measurement result of the first cycle of the block 21 (FIG. 2A) processed immediately before is fed back to the feedback gain G. The same conditions as the feedback conditions of the first cycle are applied to the feedback to the feedback gain G of the second and subsequent cycles.

The fluctuation of the correlation between the increase / decrease amount of the voltage command value Vc and the increase / decrease amount of the energy measurement value Em shows the same tendency in each cycle. Therefore, effective feedback control can be performed even in the modified example shown in FIG.

It goes without saying that each of the above embodiments is exemplary and the configurations shown in different examples can be partially replaced or combined. Similar actions and effects due to the same configuration of a plurality of examples will not be mentioned sequentially for each example. Furthermore, the present invention is not limited to the above-mentioned examples. For example, it will be obvious to those skilled in the art that various changes, improvements, combinations, etc. are possible.

10 Laser oscillator 11 Optical system 12 Bending mirror 13 Aperture 15 Branching optical system 16A, 16B Beam scanner 17A, 17B Lens 18 Stage 19 Optical detector 20, 20A, 20B Processing target 21 Block 22 Processing point 23 Resin layer 24 Top surface Metal film 25 Metal film on the lower surface 26 Laser pulse of the first cycle 27 Laser pulse of the second cycle 28 Laser pulse of the third cycle 29 Hole 30 Laser control device 31 Drive signal transmission unit 32 Feedback control unit 33 Parameter setting Unit 34 Cycle designation signal acquisition unit 35 Pulse energy calculation unit 40 Upper control device

Claims (6)

One cycle is a procedure in which a pulsed laser beam is output from a laser oscillator having a discharge electrode for exciting a laser medium, and the pulsed laser beam is sequentially incident on a plurality of work points of a workpiece one shot at a time. It is a laser control device incorporated in a laser processing device that repeats a plurality of cycles for a plurality of the machined points to perform laser processing.
Feedback that changes the discharge voltage applied to the discharge electrode so that the energy measurement value, which is the measurement value of the pulse energy of the pulse laser beam, is maintained at the energy target value, which is the target value of the pulse energy set for each cycle. A laser control device that controls. The control for changing the discharge voltage includes a control for increasing / decreasing a voltage command value which is a command value of the discharge voltage given to the laser oscillator according to a deviation from the energy target value to the energy measurement value, and the energy. The laser control device according to claim 1, wherein the feedback gain, which is the ratio of the increase / decrease amount of the voltage command value to the deviation from the target value to the measured energy value, is set for each cycle. The surface of the object to be machined is divided into a plurality of blocks, and a plurality of the machines to be machined are defined in each of the blocks, and the laser machining apparatus repeats a plurality of cycles for each block. Laser processing
The laser control device according to claim 2, wherein the feedback gain is updated based on the energy measurement value in the same cycle at the time of processing the block that has been processed immediately before. Moreover,
The energy target value is stored for each cycle.
When a signal specifying one of a plurality of cycles is received from the host control device of the laser processing device, the laser oscillator is controlled using the energy target value stored corresponding to the specified cycle. The laser control device according to claim 1. The laser control device according to any one of claims 1 to 4, wherein different values are used as the energy target values in at least two different cycles among the plurality of cycles. It is a method of performing laser machining by repeating a plurality of cycles for a plurality of the workpieces, with the procedure of injecting a pulsed laser beam one shot at a time into a plurality of workpieces of an object to be machined in order as one cycle. hand,
For a laser oscillator that has a discharge electrode for exciting a laser medium and outputs a pulsed laser beam, the discharge electrode has a pulse energy maintained at an energy target value, which is a target value of the pulse energy. A laser processing method in which different values are used as the energy target values in at least two different cycles when a plurality of cycles are executed while performing feedback control for changing the applied discharge voltage.

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