WO2020202440A1

WO2020202440A1 - Laser processing device, laser processing method, and error adjustment method

Info

Publication number: WO2020202440A1
Application number: PCT/JP2019/014493
Authority: WO
Inventors: 昌裕竹内
Original assignee: 三菱電機株式会社
Priority date: 2019-04-01
Filing date: 2019-04-01
Publication date: 2020-10-08
Also published as: TW202037438A; TWI787595B; JP6632781B1; JPWO2020202440A1

Abstract

A laser processing device (100) equipped with a processing table (2A), a galvano-scanner (5A) for driving a galvano-mirror (4A), a camera (7A) for observing the surface of the processing table, and a control device (10) for controlling the laser processing of a workpiece to be processed (3A), wherein a reference plate (8) on which a plurality of reference marks (M) are arranged is placed on the processing table (2A), and the control device (10) calculates a positioning error of the processing table (2A) on the basis of the measurement positions (MQ) of four or more of the reference marks (M) and operates the camera (7A) and the processing table (2A) in conjunction with each other to repeat a process for measuring the reference marks (M). The control device (10) calculates a positioning error across the entire area of the processing table (2A) and controls the laser processing of an object to be processed on the basis of the calculated positioning error.

Description

Laser processing equipment, laser processing method, and error adjustment method

The present invention relates to a laser processing apparatus for laser processing a processing work placed on a processing table, a laser processing method, and an error adjusting method.

The laser processing device performs laser processing at various positions on the processing work by moving the processing table on which the processing work is placed. Since this laser processing device has a positioning error in the processing table, the laser processing device needs to correct the irradiation position of the laser beam based on the positioning error.

The laser processing apparatus described in Patent Document 1 is a camera capable of observing a surface to be processed via a galvano scanner, detects the position of a scale mark formed on a glass scale on the galvano scanner, and detects the position of the scale mark and the detection result. Therefore, the correction value for correcting the drive amount of the galvano scanner is obtained.

Japanese Unexamined Patent Publication No. 2008-264789

However, in the technique of Patent Document 1, since the camera and the galvano scanner are not linked, the correction can be performed only within the range in which the image to be processed can be captured by the movement of the galvano scanner, and the processing table is wider than the galvano scan area. There was a problem that the above processing target area could not be corrected.

The present invention has been made in view of the above, and an object of the present invention is to obtain a laser processing apparatus capable of accurately processing a processing target area on a processing table having a wider range than a galvanoscan area.

In order to solve the above-mentioned problems and achieve the object, the laser processing apparatus of the present invention includes a processing table on which an object to be processed is placed, a galvano mirror that irradiates the object to be processed with a laser beam and scans the object, and a galvano. It includes a galvano scanner that drives a mirror, a measuring device that observes the surface of the machining table, and a control device that controls laser machining of the machining object. In the laser processing apparatus of the present invention, a reference plate on which a plurality of reference marks are arranged is placed on the processing table, and the control device determines the positioning error of the processing table based on the measurement positions of four or more reference marks. By calculating and linking the measuring device and the machining table, the process of measuring the reference mark is repeated, and the control device calculates the positioning error over the entire area of the machining table. Laser machining of the workpiece is controlled based on the calculated positioning error.

The laser processing apparatus according to the present invention has the effect of being able to accurately process the processing target area on the processing table, which is wider than the galvanoscan area.

The figure which shows the structure of the laser processing apparatus which concerns on embodiment The figure which shows the structure of the control apparatus included in the laser processing apparatus which concerns on embodiment A flowchart showing a procedure for calculating a correction coefficient by the laser processing apparatus according to the embodiment. The figure for demonstrating the measurement area of the reference plate used in the laser processing apparatus which concerns on embodiment. The figure for demonstrating the reference mark measured by the laser processing apparatus which concerns on embodiment. The figure for demonstrating the relationship between the actual position of the reference mark and the measurement position acquired by the laser processing apparatus which concerns on embodiment. A flowchart showing a procedure for calculating a galvano correction amount by the laser processing apparatus according to the embodiment. The figure for demonstrating the alignment mark used by the laser processing apparatus which concerns on embodiment. The figure which shows the hardware configuration example of the control device which concerns on embodiment

The laser processing apparatus, the laser processing method, and the error adjusting method according to the embodiment of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to this embodiment.

Embodiment.
FIG. 1 is a diagram showing a configuration of a laser processing apparatus according to an embodiment. The laser processing apparatus 100 is an apparatus that performs laser drilling on the

machining workpieces

3A and 3B while correcting the positioning error of the machining tables 2A and 2B for placing the

machining workpieces

3A and 3B which are the objects to be machined. The position correction of the processing tables 2A and 2B by the laser processing apparatus 100 is effective for processing by interlocking the

galvano scanners

5A and 5B and the processing tables 2A and 2B.

The laser processing apparatus 100 places a reference plate for measuring the positioning error on the processing tables 2A and 2B, and measures the position of the reference mark arranged on the reference plate. The reference plate is a plate on which the position of the reference mark is measured while being placed on the processing tables 2A and 2B. The laser processing apparatus 100 calculates the positioning error of the processing tables 2A and 2B based on the difference between the actual position of the reference mark and the measurement position of the reference mark, and calculates a correction coefficient for correcting the positioning error. .. The actual position of the reference mark is the design position (design value) of the reference mark, and the measurement position of the reference mark is the position of the reference mark measured with the reference plate placed on the processing tables 2A and 2B. Is.

The laser processing apparatus 100 repeats the process of measuring the reference mark by interlocking the

cameras

7A and 7B and the processing tables 2A and 2B, and calculates the correction coefficient over the entire area of the processing tables 2A and 2B. The correction coefficient is used when correcting the positions of the processing tables 2A and 2B. The laser processing apparatus 100 corrects the positions of the processing tables 2A and 2B by correcting the positions of the alignment marks arranged on the

processing works

3A and 3B on the processing tables 2A and 2B with a correction coefficient. The alignment mark is a mark whose position is measured while the

machining workpieces

3A and 3B are placed on the machining tables 2A and 2B, and is used when correcting the positions of the

machining workpieces

3A and 3B. The details of the alignment mark will be described later.

The laser processing apparatus 100 includes a processing mechanism 20 that performs laser processing on the

processing workpieces

3A and 3B that are workpieces, and a control device 10 that controls the processing mechanism 20. The control device 10 calculates the correction coefficient by using the least squares approximation or the like for each measurement area in which the reference mark is arranged. The control device 10 creates a calibration table showing the correspondence between the correction coefficient and the measurement area. The calibration table is a table for correcting the positioning error of the processing tables 2A and 2B. When controlling the laser processing, the control device 10 extracts a correction coefficient for each measurement area based on the calibration table, applies the extracted correction coefficient to each measurement area, and irradiates the

laser beams

1A and 1B. Correct the position.

The processing mechanism 20 separates the laser light (laser beam) output from the laser oscillator (not shown) into

laser light

1A and 1B on the optical path, and simultaneously lasers the

processing workpieces

3A and 3B on the processing tables 2A and 2B. Process.

The processing mechanism 20 includes a first processing unit that irradiates the processing work 3A with the laser beam 1A, and a second processing unit that irradiates the processing work 3B with the laser light 1B. The first processing portion has a galvano scanner 5A, a galvano mirror 4A, a camera 7A, an fθ lens 6A, and a processing table 2A, and the second processing portion includes a galvano scanner 5B and a galvano mirror. It has a 4B, a camera 7B, an fθ lens 6B, and a processing table 2B.

Further, the processing mechanism 20 includes a drive table 21 that drives the processing tables 2A and 2B. The processing tables 2A and 2B are XY processing tables that can be moved in an XY plane such as a horizontal plane. The machining tables 2A and 2B move the

machining workpieces

3A and 3B in the XY plane by moving in the X-axis direction and the Y-axis direction, respectively, thereby moving the

laser beams

1A and 1B onto the

machining workpieces

3A and 3B. Adjust the irradiation position.

The machining table 2A fixes the machining work 3A on the machining table 2A by adsorbing the machining work 3A, and the machining table 2B fixes the machining work 3B on the machining table 2B by adsorbing the machining work 3B. As described above, the machining mechanism 20 is configured such that two machining tables 2A and 2B are attached to the drive table 21 and two

machining workpieces

3A and 3B can be machined at the same time.

Both the machining tables 2A and 2B are placed on the drive table 21, but the amount of error is different between the positioning error of the machining table 2A and the positioning error of the machining table 2B. Therefore, the control device 10 separately calculates the correction coefficient for the machining table 2A and the correction coefficient for the machining table 2B.

The processing mechanism 20 may be a processing mechanism that laser-processes one processing work with one laser light without separating the laser light. That is, the processing mechanism 20 may be a processing mechanism having one of a first processed portion and a second processed portion. Since the first processed portion and the second processed portion perform the same operation with the same configuration, the configuration and operation of the first processed portion will be described below.

The galvano scanner 5A positions the irradiation position of the laser beam 1A at a high speed at the machining target position on the machining work 3A. The galvano scanner 5A includes a galvano mirror 4A, a servomotor (not shown) that drives the galvano mirror 4A, and a drive control device (not shown) that controls the drive of the servomotor. In the galvano scanner 5A, the drive control device drives the galvano mirror 4A, and the galvano mirror 4A scans the machining workpiece 3A with the laser beam 1A from the laser oscillator.

In the galvano scanner 5A, the drive control device rotates, for example, the galvano mirror 4A within a specific swing angle range. The galvano scanner 5A receives a command from the control device 10 and moves the irradiation position of the laser beam 1A so that the laser beam 1A is irradiated to the target processing position in the scan area. In this way, in the galvano scanner 5A, the drive control device drives the galvano mirror 4A so that the laser beam 1A is irradiated to a specific position in each scan area in the machining surface of the machining work 3A. The scan area is the area scanned by the Galvano Mirror 4A. The scan area corresponds to the driveable area of the galvano scanner 5A. After the laser beam 1A is irradiated, the galvano scanner 5A repeats the operation of moving the irradiation position of the laser beam 1A to the next target position and stopping the operation.

The first processing section has two galvano scanners 5A and two galvano mirrors 4A. In the first processing section, the irradiation position of the laser beam 1A on the processing work 3A is moved in the X-axis direction by rotating the galvano mirror 4A of one of the galvano scanners 5A. Further, in the first processing section, the irradiation position of the laser beam 1A on the processing work 3A is moved in the Y-axis direction by rotating the galvano mirror 4A of the other galvano scanner 5A. The laser beam 1A reflected by one galvano mirror 4A is sent to the other galvano mirror 4A and reflected by the other galvano mirror 4A. The laser beam 1A reflected by the other galvanometer mirror 4A is applied to the machining work 3A.

The fθ lens 6A concentrates the laser beam 1A on the processing work 3A placed on the processing table 2A. The camera 7A, which is a measuring device, observes the surface of the processing table 2A and measures the positions of various marks. When calculating the correction coefficient, the camera 7A detects the position (coordinates) of the reference mark arranged on the reference plate on the processing table 2A. When the machining work 3A is placed on the machining table 2A, the camera 7A detects the position (coordinates) of the alignment mark placed on the machining work 3A.

The alignment mark is a mark for correcting the position of the machining work 3A. The machining work 3A placed on the machining table 2A may be displaced due to distortion, expansion and contraction, and the like. The laser processing apparatus 100 detects the position of the alignment mark and corrects the coordinates in the processing work 3A based on the position of the alignment mark and the correction coefficient.

The camera 7A sends the position of the reference mark, which is the detection result of the reference mark, and the position of the alignment mark, which is the detection result of the alignment mark, to the control device 10.

In the laser processing apparatus 100, the laser beam 1A from the laser oscillator is irradiated into the scan area of the processing work 3A via the galvano mirror 4A attached to each axis and the fθ lens 6A.

Since the area of the machining work 3A is larger than the area of the scan area, the laser machining apparatus 100 moves the machining table 2A from the scan area to the next scan area, and sets the irradiation position of the laser beam 1A in the scan area to the galvano scanner. Move at 5A. That is, the laser processing apparatus 100 moves the irradiation position of the laser beam 1A between the scan areas by the processing table 2A, and moves the irradiation position of the laser beam 1A within the scan area by the galvano scanner 5A. The laser processing apparatus 100 laser-processes the entire processing region of the processing work 3A by irradiating each scan area with laser light 1A. That is, the laser processing apparatus 100 has a configuration in which the entire area of the processing work 3A is processed by repeating the process of moving the processing table 2A to each scan area and the process of irradiating the laser beam 1A in each scan area. ing.

The control device 10 is a computer that controls the processing mechanism 20. The control device 10 controls the drive of the processing table 2A, the laser oscillator, the

galvano scanners

5A, 5B, and the like. The control device 10 of the embodiment calculates a calibration table based on the information sent from the machining mechanism 20, and corrects the positioning error of the machining table 2A by using the calibration table. The control device 10 corrects the position of the machining work 3A by using the correction coefficient stored in the calibration table, and corrects the drive amount of the galvano scanner 5A based on the corrected position. The control device 10 corrects the position of the galvano mirror 4A by correcting the driving amount of the galvano scanner 5A, thereby correcting the irradiation position of the laser beam 1A.

Here, the configuration of the control device 10 will be described. FIG. 2 is a diagram showing a configuration of a control device included in the laser processing device according to the embodiment. The control device 10 includes an input unit 11, a correction coefficient calculation unit 12, a storage unit 13, a correction amount calculation unit 14, and a control unit 15.

The input unit 11 receives the position of the reference mark sent from the camera 7A of the processing mechanism 20 and inputs it to the control unit 15. Hereinafter, the position of the reference mark sent from the camera 7A is referred to as a measurement position. The input unit 11 receives the position of the alignment mark sent from the camera 7A of the processing mechanism 20 and inputs it to the correction amount calculation unit 14.

The correction coefficient calculation unit 12 reads out from the storage unit 13 information indicating the correspondence between the actual position of the reference mark arranged in each measurement area of the reference plate and the measurement area. Further, the correction coefficient calculation unit 12 reads out information indicating the correspondence between the measurement position of the reference mark and the measurement area from the storage unit 13.

The position of the measurement area of the reference plate corresponds to the position of the processing table 2A. The actual position of the reference mark is the design value. Hereinafter, the actual position of the reference mark is referred to as an actual position, and the information indicating the correspondence between the actual position and the measurement area is referred to as the actual position information. Further, information indicating the correspondence between the measurement position and the measurement area is referred to as measurement position information.

The correction coefficient calculation unit 12 calculates the difference between the actual position and the measurement position based on the actual position information and the measurement position information. The correction coefficient calculation unit 12 calculates a correction coefficient for correcting the position of the measurement area based on the difference between the actual position and the measurement position. The correction coefficient calculation unit 12 calculates the correction coefficient for each measurement area, and sends information indicating the correspondence between the correction coefficient and the measurement area to the storage unit 13. Hereinafter, the information indicating the correspondence between the correction coefficient and the measurement area is referred to as correction coefficient information.

The storage unit 13 stores the actual position information. Further, the storage unit 13 stores the measurement position information sent from the control unit 15. Further, the storage unit 13 stores the correction coefficient information sent from the correction coefficient calculation unit 12.

The correction amount calculation unit 14 reads the correction coefficient information from the storage unit 13. The correction amount calculation unit 14 corrects the position (coordinates) of the alignment mark using the correction coefficient information. Specifically, the correction amount calculation unit 14 specifies the measurement area corresponding to the position of the alignment mark, and extracts the correction coefficient corresponding to the specified measurement area from the correction coefficient information. The correction amount calculation unit 14 corrects the position of the alignment mark using the extracted correction coefficient. The position of the alignment mark corrected by using the correction coefficient is an accurate position of the alignment mark in consideration of the position error of the machining table 2A, the misalignment of the machining work 3A, and the like. Therefore, the correction amount calculation unit 14 sets the position of the machining table 2A and the drive correction amount for correcting the drive amount of the galvano scanner 5A (hereinafter referred to as galvano correction amount) based on the position of the corrected alignment mark. Calculate the formula showing the correspondence. This mathematical formula is a mathematical formula that can obtain the galvano correction amount corresponding to the coordinates on the machining table 2A by substituting the X coordinate and the Y coordinate on the machining table 2A. The coordinates (X coordinate and Y coordinate) of the processing table 2A are the center coordinates of the scan area by the galvano scanner 5A.

The correction amount calculation unit 14 calculates the galvano correction amount corresponding to this position based on the position of the processing table 2A specified by the processing program. The correction amount calculation unit 14 sends the calculated galvano correction amount to the control unit 15.

The control unit 15 controls the processing mechanism 20. The control unit 15 sends a drive instruction to the galvano scanner 5A, the processing table 2A, and the like. The control unit 15 moves the imaging position of the camera 7A to the position of the reference mark arranged in the measurement area by moving the processing table 2A when the correction coefficient information is calculated. The imaging position of the camera 7A is the center position of the scan area. The control unit 15 generates measurement position information in which the measurement area corresponding to the imaging position of the camera 7A is associated with the actual position sent from the input unit 11. The actual position sent from the input unit 11 is the actual position measured in the measurement area corresponding to the imaging position of the camera 7A. The control unit 15 sends the measurement position information to the storage unit 13.

Further, when driving the galvano scanner 5A, the control unit 15 corrects the driving amount of the galvano scanner 5A by using the galvano correction amount for each table position which is the position of the processing table 2A. The control unit 15 sends a drive instruction corrected for the drive amount of the galvano scanner 5A to the processing mechanism 20. As a result, the swing angle of the galvano mirror 4A is corrected, so that the irradiation position of the laser beam 1A is corrected.

As described above, the control device 10 of the embodiment calculates the galvano correction amount for correcting the positioning error of the machining table 2A by using the measurement position of the reference mark, and uses the galvano correction amount to generate the galvano scanner 5A. Drive.

Next, the procedure for calculating the correction coefficient by the laser processing apparatus 100 will be described. FIG. 3 is a flowchart showing a procedure for calculating a correction coefficient by the laser processing apparatus according to the embodiment. FIG. 4 is a diagram for explaining a measurement area of a reference plate used in the laser processing apparatus according to the embodiment. FIG. 5 is a diagram for explaining a reference mark measured by the laser processing apparatus according to the embodiment.

When calculating the correction coefficient, the laser processing apparatus 100 measures the position of the reference mark M with the position correction of the processing table 2A disabled, and calculates the correction coefficient based on the measured position. This is because the position deviation of the reference mark M cannot be measured when the position correction is enabled. Therefore, the control device 10 of the laser processing device 100 invalidates the position correction of the processing table 2A when the position correction of the processing table 2A is enabled (step S1). That is, when the setting for correcting the drive amount of the galvano scanner 5A is valid, the laser processing apparatus 100 invalidates the setting for correcting the drive amount of the galvano scanner 5A.

A reference plate 8 as a reference for creating a calibration table is placed on the processing table 2A. The reference plate 8 has a plurality of reference marks M printed on the upper surface of the reference plate 8 at equal intervals. The reference marks M are arranged in a grid pattern in a region that can cover the entire surface of the processing table 2A. The reference mark M may be arranged on the upper surface of the reference plate 8 by a method other than printing. Further, the reference marks M may be arranged in a shape other than the grid pattern. The reference plate 8 is a quartz glass plate or the like having good placement accuracy of the reference mark M. In the laser processing apparatus 100, the reference plate 8 is used as the master scale of the processing table 2A, that is, the reference scale.

As shown in FIG. 4, the reference plate 8 is provided with a plurality of measurement areas such as a measurement area 30n and a measurement area 30 (n + 1) on the entire surface. Here, n is a natural number. Since each measurement area set on the reference plate 8 has the same shape and size, the measurement area 30n will be described below. The measurement area 30n is a rectangular area, and reference marks M are arranged at each of the four vertices. In FIG. 5, four reference marks M in the measurement area 30n are illustrated by reference marks P1 to P4. As for the measurement area on the reference plate 8, the larger the number of areas, that is, the narrower each measurement area, the more accurate the displacement correction can be performed.

The reference plate 8 is formed by using, for example, a plate-shaped member having an X-axis direction of 800 mm and a Y-axis direction of 600 mm. An example of a scan area corresponding to the operable area of the galvano scanner 5A is 30 mm × 30 mm.

In the reference plate 8, measurement areas adjacent to each other share two reference marks M (one side which is a line segment region between the two reference marks M). For example, the measurement area 30 (n + 1) adjacent to the measurement area 30n and the measurement area 30n share two reference marks M. Specifically, the reference marks P3 and P4 are reference marks arranged on the right side of the measurement area 30n and reference marks arranged on the left side of the measurement area 30 (n + 1). Similarly, the lower side of the measurement area 30n is shared by other measurement areas. In this way, the adjacent measurement areas share one side, so that the measurement areas are set in a grid pattern on the reference plate 8.

The laser processing apparatus 100 performs a process of moving the imaging position of the camera 7A onto the reference mark Pm of the measurement area 30n, a process of measuring the position of the reference mark Pm, and a process of storing the measurement data m = 1 to 4. Repeat until. Specifically, the control unit 15 moves the processing table 2A to a table position where the imaging position of the camera 7A is on the reference mark P1 of the measurement area 30n. The imaging position of the camera 7A is a position on the reference plate 8 imaged by the camera 7A. That is, the laser processing apparatus 100 moves the processing table 2A on which the reference plate 8 is placed in a plane parallel to the table surface of the processing table 2A, so that the imaging position of the camera 7A is moved on the reference mark P1 in the measurement area 30n. (Step S2).

The laser processing apparatus 100 measures the position of the reference mark P1 with the camera 7A (step S3). In FIG. 5, the measurement position which is the measurement result of the reference mark P1 is shown at the measurement position Q1. The laser processing device 100 sends the measurement position Q1 to the control device 10. As a result, the laser processing apparatus 100 saves the measurement data (step S4). Specifically, the laser processing apparatus 100 associates the measurement area 30n with the measurement position Q1 of the reference mark P1 and stores it in the storage unit 13.

The laser processing apparatus 100 determines whether or not the position has been measured from the reference mark P1 to the reference mark P4 (step S5). When the position is not measured up to the reference mark P4 (step S5, No), the laser processing apparatus 100 repeats the processes of steps S2 to S5. That is, the laser processing apparatus 100 repeats the processes of steps S2 to S5 until the position of the reference mark P4 is measured (until m = 4).

That is, the laser processing apparatus 100 moves the processing table 2A to the position of the reference mark P2 (step S2), measures the position of the reference mark P2 (step S3), and uses the measurement area 30n and the measurement result of the reference mark P2. It is stored in the storage unit 13 in association with a certain measurement position Q2 (step S4).

Similarly, the laser processing apparatus 100 moves the processing table 2A to the position of the reference mark P3 (step S2), measures the position of the reference mark P3 (step S3), and measures the measurement area 30n and the reference mark P3. It is stored in the storage unit 13 in association with the measurement position Q3 (step S4).

Similarly, the laser processing apparatus 100 moves the processing table 2A to the position of the reference mark P4 (step S2), measures the position of the reference mark P4 (step S3), and measures the measurement area 30n and the reference mark P4. It is stored in the storage unit 13 in association with the measurement position Q4 (step S4). In this way, by moving the processing table 2A, the reference mark is sequentially moved to the measurement position by the camera 7A. The information in which the measurement area 30n and the measurement positions Q1 to Q4 are associated with each other is the measurement position information.

When the position is measured up to the reference mark P4 (step S5, Yes), the correction coefficient calculation unit 12 reads the actual position information and the measurement position information from the storage unit 13, and based on the actual position information and the measurement position information, sets the actual position. Calculate the difference from the measurement position. The correction coefficient calculation unit 12 calculates the correction coefficient for each measurement area based on the difference between the actual position and the measurement position, and stores the correction coefficient in the storage unit 13 (step S6). At this time, the correction coefficient calculation unit 12 calculates the correction coefficient by the least squares approximation using the four actual positions of the reference marks P1 to P4 and the four measurement positions Q1 to Q4 which are the measurement positions. Specifically, the correction coefficient calculation unit 12 calculates the correction coefficient by applying the least squares approximation to the difference between the four actual positions and the four measurement positions Q1 to Q4. Further, the correction coefficient calculation unit 12 may calculate the correction coefficient for the table position in the measurement area 30n by performing parallelogram correction or trapezoidal correction in addition to the calculation of the correction coefficient.

The camera 7A is not limited to measuring the positions of the reference marks P1 to P4 at four points within the measurement area 30n, and may measure the positions of the reference marks at five or more points. That is, it suffices that four or more (at least four) reference marks are arranged in the measurement area 30n. In this case, the camera 7A measures four or more reference marks in the measurement area 30n, and the correction coefficient calculation unit 12 calculates the correction coefficient using the measurement position information of the four or more reference marks. Here, the reason why the positions of the four or more reference marks are measured is that if the positions of the four or more reference marks are known, the correction coefficients in the X-axis direction and the Y-axis direction can be calculated easily and accurately. Is.

The control unit 15 determines whether or not the correction coefficients have been calculated for all the measurement areas (step S7). When there is a measurement area for which the correction coefficient has not been calculated (step S7, No), the laser processing apparatus 100 follows the instruction from the control unit 15 for the measurement area for which the correction coefficient has not been calculated, from steps S2 to S6. Executes the processing of. The laser processing apparatus 100 executes the processes of steps S2 to S6 in each measurement area until the correction coefficients are calculated for all the measurement areas. When the measurement area for which the correction coefficient has not been calculated disappears (step S7, Yes), the laser processing apparatus 100 ends the calculation process of the correction coefficient.

The correction coefficient calculation unit 12 creates a calibration table showing the correspondence between the correction coefficient and the measurement area by using the calculated correction coefficient for all the measurement areas. When the correction coefficient calculation unit 12 calculates the correction coefficient in each measurement area by performing parallelogram correction or keystone correction, the calibration table also has high accuracy for the table position between the reference marks in the measurement area 30n. Can be created.

FIG. 6 is a diagram for explaining the relationship between the actual position of the reference mark and the measurement position acquired by the laser processing apparatus according to the embodiment. FIG. 6 shows the correspondence between the actual position AP of the reference mark M arranged on the reference plate 8 and the measurement position MQ. In FIG. 6, the difference between the actual position AP and the measurement position MQ is multiplied by 1000. The actual position AP is arranged on the entire surface of the reference plate 8, and the laser processing apparatus 100 measures the measurement position MQ for each actual position AP. The measurement position MQ that overlaps the actual position AP is the measurement position MQ corresponding to the actual position AP. When the reference plate 8 is fixed to the processing table 2A with reference to the reference point BP at the upper left position in the entire area of the reference plate 8, the position farther from the reference point BP is the reference position and the actual position. The difference (error) between them becomes large.

The laser processing apparatus 100 calculates the galvano correction amount after calculating the correction coefficient information, and executes laser processing of the machining work 3A using the galvano correction amount. Here, the procedure for calculating the galvano correction amount by the laser processing apparatus 100 will be described.

FIG. 7 is a flowchart showing a procedure for calculating a galvano correction amount by the laser processing apparatus according to the embodiment. The laser processing apparatus 100 starts processing the processing work 3A in a state where the reference plate 8 is removed from the processing table 2A and the processing work 3A is placed on the processing table 2A.

The laser processing apparatus 100 enables the position correction of the processing table 2A (step S11). The laser processing apparatus 100 moves the imaging position of the camera 7A to the position of the alignment mark of the processing work 3A (step S12). That is, the laser processing apparatus 100 moves the imaging position of the camera 7A to the table position corresponding to the alignment mark by moving the processing table 2A. The camera 7A measures the position of the alignment mark (step S13).

FIG. 8 is a diagram for explaining an alignment mark used by the laser processing apparatus according to the embodiment. FIG. 8 shows the machining work 3A when the machining work 3A placed on the machining table 2A is viewed from the upper surface side. Alignment marks 9 are arranged at the positions of the four vertices of the machining work 3A or near the positions of the vertices.

The camera 7A sends the position of the alignment mark 9, which is the measurement result of the alignment mark 9, to the control device 10. The correction amount calculation unit 14 of the control device 10 calculates the alignment correction amount based on the position of the alignment mark 9 and the correction coefficient information, and applies it to the correction of the position of the alignment mark 9 (step S14). The alignment correction amount is a correction amount for correcting the position of the alignment mark 9.

The control unit 15 determines whether or not the alignment correction amount has been calculated for all the alignment marks 9 (step S15). When there is an alignment mark 9 for which the alignment correction amount has not been calculated (step S15, No), the laser processing apparatus 100 steps with respect to the alignment mark 9 for which the alignment correction amount has not been calculated, in accordance with the instruction from the control unit 15. The process of step S14 is executed from S12. The laser processing apparatus 100 executes the processes of steps S12 to S14 in each measurement area until the alignment correction amount is calculated for all the alignment marks 9. When the alignment mark 9 for which the alignment correction amount has not been calculated disappears (step S15, Yes), the correction amount calculation unit 14 determines the galvano correction amount at the time of laser processing of each table position based on the calculated plurality of alignment correction amounts. Is calculated (step S16).

In this way, the control device 10 calculates the positioning error of the machining table 2A in each measurement area based on the measurement position MQ of the reference mark, calculates the correction coefficient for correcting the positioning error based on the positioning error, and calculates the correction coefficient. Is used to correct the position of the alignment mark 9, and the galvano correction amount is calculated based on the corrected position of the alignment mark 9.

The correction amount calculation unit 14 calculates the galvano correction amount for each table position, and the control unit 15 executes laser processing while correcting the drive amount of the galvano scanner 5A using the galvano correction amount for each table position. As a result, the swing angle of the galvano mirror 4A is corrected for each table position, so that the irradiation position of the laser beam 1A is corrected for each table position. Since the correction of the irradiation position of the laser beam 1A is a correction corresponding to the positioning error of the machining table 2A, the laser machining apparatus 100 corrects the positioning error of the machining table 2A for each table position, and the machining work 3A Laser processing can be performed.

According to this embodiment, the positioning accuracy of the machining table 2A has been improved from 13.33 μm to 6.46 μm. That is, the positioning error when the positioning error of the machining table 2A was not corrected was 13.33 μm, whereas the positioning error when the laser machining apparatus 100 used the reference plate 8 corrected the positioning error of the machining table 2A. The positioning error was 6.46 μm.

Further, according to the present embodiment, the positioning accuracy of the processing table 2B has been improved from 11.65 μm to 7.62 μm. That is, the positioning error when the positioning error of the machining table 2B was not corrected was 11.65 μm, whereas the positioning error when the laser machining apparatus 100 used the reference plate 8 corrected the positioning error of the machining table 2B. The positioning error was 7.62 μm.

The machining table 2A has a squareness or straightness that depends on the machining accuracy of the machining table 2A itself. Therefore, when the machining table 2A is moved, not only a one-dimensional deviation for each movement axis but also a two-dimensional deviation (rotational deviation) occurs. In the present embodiment, the correction coefficient is calculated by the least squares approximation using the four actual positions of the reference marks P1 to P4 and the four measurement positions Q1 to Q4 for the measurement area 30n. It is possible to correct the two-dimensional deviation of the movement of 2A.

Further, in the present embodiment, the machining table 2A is moved without driving the galvano scanner 5A, and a calibration table for correcting the positioning error of the machining table 2A is created. Therefore, it is possible to obtain a correction coefficient that can bring the positioning error of the machining table 2A at the actual position AP of the reference mark M close to 0 by creating the table once. Therefore, the time required to create the calibration table can be reduced, and the accuracy of correcting the positioning error can be improved, so that efficient and highly accurate laser processing can be realized.

Further, by performing parallelogram correction or keystone correction, a correction coefficient can be obtained for the table position within the measurement area 30n, so that the machining table 2A can be positioned with high accuracy even between the reference marks M. The error can be corrected.

Here, the hardware configuration of the control device 10 will be described. FIG. 9 is a diagram showing a hardware configuration example of the control device according to the embodiment. The control device 10 can be realized by the processor 301, the memory 302, and the interface circuit 303 shown in FIG. The processor 301, the memory 302, and the interface circuit 303 can send and receive data to and from each other by a bus. An example of the processor 301 is a CPU (Central Processing Unit, central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, processor, DSP (Digital Signal Processor)) or system LSI (Large Scale Integration). An example of the memory 302 is a RAM (Random Access Memory) or a ROM (Read Only Memory).

The control device 10 is realized by the processor 301 reading and executing a program stored in the memory 302 for executing the operation of the control device 10. It can also be said that this program causes a computer to execute the procedure or method of the control device 10. The memory 302 is also used as a temporary memory when the processor 301 executes various processes.

The program executed by the processor 301 may be a computer program product having a computer-readable and non-transitory recording medium containing a plurality of instructions for performing data processing, which can be executed by a computer. .. The program executed by the processor 301 causes the computer to execute data processing by a plurality of instructions.

Further, the control device 10 may be realized by dedicated hardware. Further, the functions of the control device 10 may be partially realized by dedicated hardware and partly realized by software or firmware.

In the present embodiment, the processing mechanism 20 separates the laser beam into two

laser beams

1A and 1B, and simultaneously performs laser processing of two

processing workpieces

3A and 3B on the two processing tables 2A and 2B. However, the configuration of the processing mechanism 20 is not limited to this configuration. The machining mechanism 20 may have a configuration in which a plurality of machining workpieces are machined on one machining table, or a plurality of machining tables may be attached to a plurality of drive systems to machine a plurality of machining workpieces. ..

As described above, according to the embodiment, the positioning error of the machining table 2A is calculated based on the measurement positions of the reference marks at four or more points, and the reference marks are measured by linking the camera 7A and the machining table 2A. Since the positioning error is calculated over the entire area of the processing table 2A by repeating the processing, the range that the galvano scanner 5A can handle (the range in which the image to be processed can be captured by the movement of the galvano scanner 5A), that is, the galvano scan area. The galvano correction amount for the positioning error can be calculated for a large machining target area. Therefore, it is possible to accurately process a processing target area larger than the range that the galvano scanner 5A can handle. Further, since the positioning error of the machining table 2A is calculated based on the measurement position MQ of the reference marks M at four or more points and the galvano correction amount is calculated based on the positioning error, the accuracy corresponding to the positioning error of the machining table 2A is calculated. The high galvano correction amount can be calculated in a short time. Therefore, highly accurate machining can be realized in a short time.

The configuration shown in the above-described embodiment shows an example of the content of the present invention, can be combined with another known technique, and is one of the configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

1A, 1B laser light, 2A, 2B processing table, 3A, 3B processing work, 4A, 4B galvano mirror, 5A, 5B galvano scanner, 6A, 6B fθ lens, 7A, 7B camera, 8 reference plate, 9 alignment mark, 10 Control device, 11 input unit, 12 correction coefficient calculation unit, 13 storage unit, 14 correction amount calculation unit, 15 control unit, 20 processing mechanism, 21 drive table, 30n, 30 (n + 1) measurement area, 100 laser processing equipment, AP Actual position, BP reference point, M, P1 to P4 reference mark, MQ, Q1 to Q4 measurement position.

Claims

A processing table on which the object to be processed is placed, and
A galvano mirror that irradiates the processed object with laser light to scan it,
A galvano scanner that drives the galvano mirror,
A measuring device for observing the surface of the processing table and
A control device that controls laser processing of the object to be processed, and
With
A reference plate on which a plurality of reference marks are arranged is placed on the processing table.
The control device calculates the positioning error of the processing table based on the measurement positions of the reference marks at four or more locations, and calculates the positioning error.
By interlocking the measuring device and the processing table, the process of measuring the reference mark is repeated, and the control device calculates the positioning error over the entire area of the processing table and is based on the calculated positioning error. To control the laser processing of the processing object,
A laser processing device characterized by this.
The measuring device measures four or more reference marks in a rectangular area on the processing table.
The laser processing apparatus according to claim 1.
The control device calculates a drive correction amount of the galvano scanner for correcting the positioning error, and controls the laser processing of the machining object while driving the galvano scanner using the drive correction amount.
The laser processing apparatus according to claim 2.
The measuring device measures the position of the alignment mark provided on the machined surface of the machined object while the machined object is placed on the machined table.
The control device calculates a correction coefficient for correcting the positioning error, corrects the measurement position of the alignment mark using the correction coefficient, and calculates the drive correction amount based on the corrected measurement position of the alignment mark. To do,
The laser processing apparatus according to claim 3.
The control device calculates the drive correction amount by using the positioning error of the rectangular region corresponding to the position of the alignment mark among the positioning errors.
The laser processing apparatus according to claim 4.
The control device applies a least squares approximation to the difference between the actual position of the reference mark and the measurement position to calculate the positioning error of the rectangular region.
The laser processing apparatus according to any one of claims 2 to 5, wherein the laser processing apparatus is characterized.
The control device calculates the positioning error in the rectangular region by parallelogram correction or keystone correction.
The laser processing apparatus according to claim 6.
The rectangular area is adjacent to the adjacent rectangular area and shares an adjacent side.
The laser processing apparatus according to any one of claims 2 to 7, wherein the laser processing apparatus is characterized.
A processing table on which a processing object is placed, a galvano mirror that irradiates the processing object with a laser beam to scan the object, a galvano scanner that drives the galvano mirror, and a measuring device that observes the surface of the processing table. A mounting step of placing a reference plate on which a plurality of reference marks are arranged on the machining table with respect to the laser machining device including a control device for controlling laser machining of the machining object.
A calculation step in which the control device calculates a positioning error of the machining table based on the measurement positions of the reference marks at four or more locations.
Including
By interlocking the measuring device and the processing table, the process of measuring the reference mark is repeated, the control device calculates the positioning error over the entire area of the processing table, and based on the calculated positioning error. To control the laser processing of the processing object,
A laser processing method characterized by this.
A processing table on which a processing object is placed, a galvano mirror that irradiates the processing object with a laser beam to scan the object, a galvano scanner that drives the galvano mirror, and a measuring device that observes the surface of the processing table. A mounting step of placing a reference plate on which a plurality of reference marks are arranged on the machining table with respect to the laser machining device including a control device for controlling laser machining of the machining object.
A calculation step in which the control device calculates a positioning error of the machining table based on the measurement positions of the reference marks at four or more locations.
Including
By interlocking the measuring device and the processing table, the process of measuring the reference mark is repeated, the control device calculates the positioning error over the entire area of the processing table, and laser processing of the processing object. To correct the positioning error when controlling
An error adjustment method characterized by that.