JP7066368B2 - Laser machining machine control device, laser machining method, and laser machining machine - Google Patents

Description

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

A laser processing machine that performs processing by injecting a pulsed laser beam onto an object to be processed via a beam scanner and a condenser lens is known (for example, Patent Document 1). The beam scanner is calibrated before the actual machining in order to inject the pulsed laser beam into the target position of the machining object.

Japanese Unexamined Patent Publication No. 2004-66300

Despite the calibration of the beam scanner, it was found that the position where the pulsed laser beam actually incident may deviate from the target position. An object of the present invention is a control device of a laser processing machine capable of reducing a deviation between an incident position of a laser beam after calibration of a beam scanner and a target incident position, a laser processing method, and laser processing. To provide an opportunity.

According to one aspect of the invention
A control device that controls a laser processing machine having a beam scanner that moves the incident position of the pulsed laser beam on the surface of the object to be processed by scanning the pulsed laser beam output from the laser light source.
A function for controlling the output timing of a pulsed laser beam from the laser light source,
The function of instructing the beam scanner to indicate the target position for incident the pulsed laser beam, and the control of the laser light source based on the pulse frequency at the time of actual processing, the target position for calibration of the evaluation sample. The beam scanner is controlled so that the pulsed laser beam is incident on a plurality of points for calibration, and the beam scanner is based on the target positions of the plurality of points for calibration and the incident positions of the pulsed laser beam . A control device for a laser processing machine having a function of performing calibration is provided.

According to another aspect of the invention
It is a laser processing method in which a pulsed laser beam output from a laser light source is scanned by a beam scanner, and the pulsed laser beam is sequentially incident on a plurality of work points on the surface of the object to be processed to perform processing.
While outputting the pulsed laser beam based on the pulse frequency at the time of actual processing, the pulsed laser beam is incident at multiple points for calibration of the evaluation sample as target positions .
A laser processing method for calibrating the beam scanner based on the target position and the incident position of the actual pulsed laser beam is provided.

According to yet another aspect of the invention.
A laser light source that outputs a pulsed laser beam and
A beam scanner that moves the incident position of the pulsed laser beam on the surface of the workpiece by scanning the pulsed laser beam output from the laser light source.
A laser processing machine having the above control device is provided.

It is possible to reduce the deviation between the incident position of the laser beam after calibration of the beam scanner and the target incident position.

FIG. 1 is a schematic view of a laser processing machine according to an embodiment. FIG. 2 is a schematic diagram showing an optical path from a laser light source to an object to be machined. FIG. 3 is a schematic plan view of the object to be processed. FIG. 4 is a flowchart of a laser processing method using a laser processing machine according to an embodiment.

A laser beam machine according to an embodiment will be described with reference to FIG.
FIG. 1 is a schematic view of a laser processing machine according to an embodiment. The laser light source 10 outputs a pulsed laser beam. As the laser light source 10, for example, a carbon dioxide laser oscillator can be used. The pulsed laser beam output from the laser light source 10 is incident on the workpiece 30 held on the stage 17 via the acoustic optical element (AOM) 11, the mirror 12, the beam scanner 13, and the condenser lens 14. ..

The AOM 11 cuts out a part used for processing from the laser pulse of the pulsed laser beam output from the laser light source 10 by a command from the control device 20. The cut out laser pulse is directed to the object to be machined 30, and the remaining pulsed laser beam is incident on the beam damper 15.

The beam scanner 13 receives a command from the control device 20 and scans the laser beam in a two-dimensional direction to move the incident position of the pulsed laser beam on the surface of the workpiece 30. As the beam scanner 13, for example, a galvano scanner having a pair of galvano mirrors can be used.

The condenser lens 14 concentrates the pulsed laser beam scanned by the beam scanner 13 on the surface (processed surface) of the object 30 to be processed. As the condenser lens 14, for example, an fθ lens can be used.

The stage 17 receives a command from the control device 20 to move the workpiece 30 in a two-dimensional direction parallel to its surface. As the stage 17, for example, an XY stage can be used.

The image pickup apparatus 16 is arranged above the stage 17. The image pickup apparatus 16 takes an image of the surface of the processing object 30 held on the stage 17 or the evaluation sample, and generates image data. The image data generated by the image pickup device 16 is read into the control device 20.

The control device 20 has a function of controlling the output timing of the pulsed laser beam from the laser light source 10. Further, the control device 20 has a function of instructing the beam scanner 13 at a target position for incident the pulsed laser beam. Further, the control device 20 has a function of detecting the incident position of the pulsed laser beam by analyzing the image data acquired by the image pickup device 16 and calibrating the beam scanner 13 based on the detection result.

The storage device 21 stores information necessary for laser machining, for example, position information of a work point of a machining object 30, machining order information, calibration result information of a beam scanner 13, and the like.

A lens system, an aperture, or the like may be arranged in the optical path of the pulsed laser beam from the laser light source 10 to the object to be processed 30 as needed.

Next, the optical path from the laser light source 10 of the laser machine according to the embodiment to the object to be machined 30 will be described with reference to FIG. In FIG. 2, one virtual lens 35 represents an optical system arranged in an optical path from a laser light source 10 to an object 30 to be processed. The virtual lens 35 forms an image of the outlet 10A of the laser light source 10 at the image formation point Pi. An image point of the outlet 10A may be formed on the optical axis of the optical system from the laser light source 10 to the object 30 to be processed. In this case as well, the outlet 10A is finally the imaging point Pi. Is imaged in. In some cases, the aperture is placed at the position of the image point.

The stage 17 (FIG. 1) sets the object to be machined 30 in a state where the surface of the object to be machined 30 is displaced from the imaging point Pi in the optical axis direction (height direction in FIG. 1). Hold. For example, the stage 17 has an elevating function, and the control device 20 controls the stage 17 to realize such a deviated state. By arranging the surface of the object to be machined 30 at a position deviated from the image formation point Pi, the beam spot can be narrowed down to a smaller size on the surface of the object to be machined 30.

From the verification experiment of the inventor of the present application, it has been found that when the pulse frequency of the pulsed laser beam output from the laser light source 10 is changed, the emission direction of the laser beam may change. Even if the emission direction of the laser beam changes, the position of the imaging point Pi does not change. When processing is performed at the image formation point Pi, there is no deviation in the processing position.

However, when the surface of the object to be processed 30 is arranged at a position deviated from the image formation point Pi, the incident position of the pulsed laser beam fluctuates according to the fluctuation of the emission direction. For example, the pulsed laser beam following the optical path OP1 is incident on the point P1 on the surface of the object to be machined 30, and the pulsed laser beam following the optical path OP2 is incident on the point P2 on the surface of the object to be processed 30.

For example, if the beam scanner 13 is calibrated at the pulse frequency when the laser beam follows the optical path OP1 and the processing is performed with the laser beam that follows the optical path OP2, the incident position of the pulsed laser beam at the time of processing deviates from the target position. It ends up.

Next, a laser processing method using a laser processing machine according to an embodiment will be described with reference to FIGS. 3 and 4.

FIG. 3 is a schematic plan view of the object to be processed 30. A plurality of unit scanning regions 31 are defined on the surface of the object to be machined 30. A plurality of work points 32 are defined inside each of the unit scanning regions 31. By operating the beam scanner 13 (FIG. 1) without moving the object to be machined 30, the pulsed laser beam can be incident on any position in one unit scanning region 31.

When the processing in one unit scanning area 31 is completed, the stage 17 is driven to move the unprocessed unit scanning area 31 to a position where the beam scanner 13 can scan. By repeating this process, all the unit scanning regions 31 can be processed.

FIG. 4 is a flowchart of a laser processing method using a laser processing machine according to an embodiment. First, the control device 20 acquires information regarding the pulse frequency during actual machining (step S1). Hereinafter, a method of acquiring information on the pulse frequency during actual processing will be described.

The storage device 21 stores information on the positions of a plurality of work points defined on the surface of the object to be machined 30 and information on the order of machining. At the time of processing, after the pulsed laser beam is incident on one machined point, the control device 20 commands the beam scanner 13 to the target position, and the incident position of the laser beam is set to the position of the machined point to be machined next. Move it. After the beam scanner 13 is set, the control device 20 commands the laser light source 10 to output the pulsed laser beam. When the distance from one machined point to the next machined point to be machined is long, it takes a long time for the beam scanner 13 to settle. Therefore, the pulse interval of the pulsed laser beam becomes long (the pulse frequency becomes low).

The control device 20 operates the beam scanner 13 so that the incident position of the pulsed laser beam sequentially traces a plurality of work points of the workpiece 30 without outputting the pulsed laser beam from the laser light source 10. At this time, the time until the beam scanner 13 is settled is measured for all the workpiece points. After the incident position of the laser beam traces all the work points in the unit scanning region 31 (FIG. 3) in order, information on the pulse frequency is acquired. This process is executed for all the unit scanning areas 31. For example, the information on the pulse frequency includes the settling time of the beam scanner 13 for each machined point in each unit scanning region 31 and the time for the pulsed laser beam to be incident on the machined point after settling (actually from the output command of the pulsed laser beam). Includes the delay time until the pulsed laser beam is output, the pulse width, etc.).

After step S1, the evaluation sample is held in the stage 17, and the surface of the evaluation sample is made to match the height of the surface of the object to be processed 30 at the time of processing. The control device 20 determines the pulse frequency based on the information regarding the pulse frequency at the time of actual processing. A pulsed laser beam is output from the laser light source 10 at a determined pulse frequency, and the pulsed laser beam is incident on a plurality of locations for calibration (step S2). If the beam scanner 13 is not set in time by the time the laser pulse is output, the laser pulse is incident on the beam damper 15 (FIG. 1) until the beam scanner 13 is set.

The pulse frequency of the pulsed laser beam incident on the evaluation sample may be, for example, a frequency between the maximum value and the minimum value of the pulse frequency when all the unit scanning regions 31 acquired in step S1 are actually processed. .. For example, it may be a statistic such as an average value, a mode value, and a median value of pulse frequencies at the time of actual processing.

After step S2, the control device 20 drives the stage 17 to arrange the evaluation sample within the angle of view of the image pickup device 16, and images the evaluation sample to acquire image data. By analyzing this image data, the incident position of the pulsed laser beam is detected and the incident position information is acquired (step S3).

After step S3, the control device 20 calibrates the beam scanner 13 based on the incident position information of the pulsed laser beam acquired in step S3 and the command value of the target position to the beam scanner 13. (Step S4). The calibration result is stored in the storage device 21.

After step S4, the object to be machined 30 is held on the stage 17, and the actual machining is performed (step S5). Step S5 is repeated until the processing of all the objects to be processed 30 is completed (step S6).

Next, the excellent effect of the laser processing machine according to the embodiment will be described.
In this embodiment, since the pulse frequency at the time of calibration is determined based on the pulse frequency at the time of actual processing, the accuracy of calibration can be improved. This makes it possible to reduce the positional deviation of the incident position of the laser beam during processing.

Next, a modification of the above embodiment will be described.
In the above embodiment, in step S1 (FIG. 4), information on the pulse frequency at the time of processing was acquired based on the operation of the beam scanner 13 at the time of actual processing. As another method, the pulse frequency at the time of processing may be fixed and the processing may be performed at a constant pulse frequency. If the beam scanner 13 is not set in time by the time the laser pulse is output, the laser pulse output during the period until the beam scanner 13 is set is incident on the beam damper 15 (FIG. 1). The pulse frequency of the pulsed laser beam incident on the evaluation sample in step S2 may be matched to the fixed pulse frequency at the time of actual processing.

Further, in the above embodiment, the statistic of the pulse frequency at the time of processing all the unit scanning regions 31 (FIG. 3) in the object to be processed 30 is defined as the pulse frequency at the time of calibration. When there is a large difference in the distribution density of the work points in the plurality of unit scanning regions 31, the statistic of the pulse frequency at the time of actual machining varies greatly for each unit scanning region 31. In such a case, it is advisable to calibrate the beam scanner 13 for each unit scanning region 31. The calibration result is stored in the storage device 21 for each unit scanning area 31. When processing the unit scanning region 31, it is preferable to drive the beam scanner 13 using the calibration result of the unit scanning region 31.

In the above embodiment, the surface of the object to be processed 30 is arranged at a position deviated from the image formation point Pi (FIG. 2) and processed, but the surface of the object to be processed 30 is moved from the image point Pi (FIG. 2). The effect can also be obtained when processing is performed without shifting. For example, even if the position of the image formation point Pi does not shift, the attenuation rate of the light intensity may change if the optical path leading to the image formation point Pi fluctuates. When the beam scanner 13 is calibrated by the method according to this embodiment, the optical path of the pulsed laser beam is almost fixed, so that the fluctuation of the light intensity is suppressed and the stability of the position detection result at the time of calibration is improved. Can be made to.

It goes without saying that the above-mentioned Examples and Modifications are examples, and partial replacement or combination of the configurations shown in the Examples and Modifications is possible. Similar effects and effects due to the same configuration of Examples and Modifications will not be mentioned sequentially for each Example and Modification. Furthermore, the present invention is not limited to the above-mentioned examples and modifications. For example, it will be obvious to those skilled in the art that various changes, improvements, combinations, etc. are possible.

10 Laser light source 10A Laser outlet 11 Acoustic optical element (AOM)
12 Mirror 13 Beam scanner 14 Condensing lens 15 Beam damper 16 Imaging device 17 Stage 20 Control device 21 Storage device 30 Processing object 31 Unit scanning area 32 Processing point 35 Virtual lens

Claims (7)

A control device that controls a laser processing machine having a beam scanner that moves the incident position of the pulsed laser beam on the surface of the object to be processed by scanning the pulsed laser beam output from the laser light source.
A function for controlling the output timing of a pulsed laser beam from the laser light source,
The function of instructing the beam scanner to indicate the target position for incident the pulsed laser beam, and the control of the laser light source based on the pulse frequency at the time of actual processing, the target position for calibration of the evaluation sample. The beam scanner is controlled so that the pulsed laser beam is incident on a plurality of points for calibration, and the beam scanner is based on the target positions of the plurality of points for calibration and the incident positions of the pulsed laser beam . A control device for a laser processing machine that has a function to perform calibration. In addition, it has an image pickup device that captures the surface of the object to be processed.
The laser processing according to claim 1, wherein the surface of the evaluation sample after the incident of the pulsed laser beam is imaged by the image pickup apparatus and the image data obtained is analyzed to acquire the incident position information of the pulsed laser beam. Machine control device. Further, claim 1 or 2 has a function of controlling the laser light source and the beam scanner in a state where the surface of the object to be machined is located at a position deviated from the imaging point of the exit of the pulsed laser beam of the laser light source. The control device for the laser processing machine described. Instead of outputting the pulsed laser beam from the laser light source, the beam scanner is operated so that the pulsed laser beam is sequentially incident on a plurality of machined points of the object to be machined. The control device for a laser processing machine according to any one of claims 1 to 3, further having a function of acquiring information on a pulse frequency. It is a laser processing method in which a pulsed laser beam output from a laser light source is scanned by a beam scanner, and the pulsed laser beam is sequentially incident on a plurality of work points on the surface of the object to be processed to perform processing.
While outputting the pulsed laser beam based on the pulse frequency at the time of actual processing, the pulsed laser beam is incident at multiple points for calibration of the evaluation sample as target positions .
A laser processing method for calibrating the beam scanner based on the target position and the incident position of the actual pulsed laser beam. The laser processing method according to claim 5 , wherein the processing is performed in a state where the surface of the object to be machined is located at a position deviated from the image formation point of the exit of the pulsed laser beam of the laser light source. A laser light source that outputs a pulsed laser beam and
A beam scanner that moves the incident position of the pulsed laser beam on the surface of the workpiece by scanning the pulsed laser beam output from the laser light source.
A laser processing machine having the control device according to any one of claims 1 to 4 .

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