TWI392551B - Laser processing device and laser processing method - Google Patents

Description

Laser processing device and laser processing method

The present invention relates to a laser processing apparatus and a laser processing method for performing laser processing on a workpiece placed on an XY table.

A laser processing apparatus that performs laser processing on a workpiece for irradiating laser light to a workpiece of a workpiece is configured as an XY table (processing table) on which a workpiece is placed. When there are irregularities of about 10 to 30 μm on the surface of the XY table, for example, the focus position of the laser light irradiated onto the workpiece on the XY table has a difference of about 10 to 30 μm due to the position on the XY table. In this case, when the focus margin of the laser light emitted from the condensing lens is 30 μm or less, there is a problem that the focus position is not matched and the processing quality is deteriorated.

In the laser processing machine described in Patent Document 1, the height of the surface of the XY table on which the workpiece is placed is measured in a lattice shape, and the height of the point is obtained by the height of four points at any point on the upper surface of the workpiece. Operation. Moreover, the imaging position of the laser is determined by the position corresponding to the calculated height.

(previous technical literature) (Patent Literature)

(Patent Document 1): JP-A-2008-73806

However, in the above-mentioned conventional technique, it is necessary to increase the number of measurement points when there are complicated irregularities on the surface of the table. In addition, it is necessary to store (X, Y, Z) 3 points of data (position coordinates) as workbench data for the measurement site at 1 point. Therefore, there is a problem of a large amount of data to be stored.

The present invention has been made in view of the above problems, and an object of the invention is to provide a laser processing apparatus and a laser processing method which can easily perform laser processing on a workpiece placed on an XY table.

In order to solve the above problems and achieve the object, the laser processing apparatus of the present invention irradiates laser light onto a workpiece placed on an XY table to perform laser processing on the workpiece, and includes a laser beam irradiation unit. The workpiece is moved to a predetermined height to irradiate the processed object with laser light, and the calculation unit calculates the thunder using each of the processing positions on the workpiece using an approximate expression modeled on the surface height of the XY table. a correction value of the height of the light-emitting portion, and when the processing of the workpiece is performed, correcting the corrected machining height by the correction value to calculate a corrected machining height; and driving the portion to move the laser beam irradiation portion to The processing height after the above correction.

According to the present invention, since the height correction value of the laser light irradiation portion is calculated for each processing position on the workpiece using an approximate expression modeled by the surface height of the XY table, it is easy to perform the corresponding XY table. The effect of surface height on the laser processing of the workpiece.

Hereinafter, a laser processing apparatus and a laser processing method according to embodiments of the present invention will be described in detail based on the drawings. Further, the present invention is not limited to the embodiment.

Implementation form

Fig. 1 is a view showing a laser processing apparatus according to an embodiment of the present invention. The laser processing apparatus 1 is a device that performs laser processing while correcting the height of the focus position during processing so that the focus position of the laser light is aligned with the unevenness of the XY table 35. In the laser processing apparatus 1 of the present embodiment, the height (surface height) of the XY table 35 is calculated as a model (model type) after the height measured at each position of the XY table 35, and the model is used. Adjust the height of the laser light irradiation position. The laser processing apparatus 1 is configured to include an fθ lens 31, a height measuring sensor 32, a camera 33, a Z-axis driving unit 34, and an XY table 35.

The fθ lens (laser light irradiation unit) 31 is a workpiece W that is emitted from a laser oscillator (not shown) and guided to the laser light on the head side to be condensed and irradiated onto the XY table 35. The laser light 30 irradiated through the fθ lens 31 determines the imaging position in accordance with the height of the fθ lens 31 in the Z-axis direction (optical axis direction). Therefore, the fθ lens 31 is moved to the height corresponding to the unevenness of the XY table 35.

The height measuring sensor 32 is a sensor that measures the heights of the XY table 35 and the workpiece W. The height measuring sensor 32 measures the height of the XY table 35 or the workpiece W, for example, by contacting the upper surface of the XY table 35 or the upper surface of the workpiece W.

The camera 33 captures the upper surface of the workpiece W. The camera 33 captures a positioning mark formed on the workpiece W when, for example, a machining position in the XY direction of the workpiece W is determined. Further, the camera 33 captures a machined hole formed in the workpiece W.

The Z-axis drive unit 34 is connected to the fθ lens 31, the height measurement sensor 32, and the camera 33. The Z-axis drive unit 34 moves the fθ lens 31, the height measurement sensor 32, and the camera 33 in the Z-axis direction by the Z-axis direction movement.

The XY table 35 mounts the workpiece W and moves in the XY plane. The XY table 35 has a main surface parallel to the XY plane, and the workpiece is placed on the main surface. The unevenness in the XY plane of the XY table 35 is measured by the height measuring sensor 32.

Fig. 2 is a functional block diagram showing the configuration of a laser processing apparatus. The laser processing apparatus 1 is configured to include a processing control unit 11 and a height control device 2. Further, the laser processing apparatus 1 includes a measurement sensor control unit 12, a height measurement sensor 32, a height data measurement unit 16, a table position measurement unit 13, an XY table 35, and a table position measurement unit 17, The lens height control unit 14, the camera height control unit 15, and the Z-axis drive unit 34. Here, the height measuring sensor 32 and the height data measuring unit 16 correspond to the height measuring unit described in the patent application. Further, in Fig. 2, the illustration of the fθ lens 31 and the camera 33 is omitted.

The machining control unit 11 controls the measurement sensor control unit 12, the table position control unit 13, the lens height control unit 14, and the camera height control unit 15. The machining control unit 11 sends a command (height measurement command) for measuring the heights of the XY table 35 and the workpiece W to the measurement sensor control unit 12. The machining control unit 11 sends a height measurement command to the measurement sensor control unit 12, for example, when calculating the Z-axis correction coefficient to be described later and the correction data Zbase of the reference position to be described later.

The machining control unit 11 sends a command (table movement command) for moving the XY table 35 in the XY plane to the table position control unit 13. The machining control unit 11 sends a table movement command to the table position control unit 13 when the machining position of the workpiece is moved and when the height of the XY table 35 is measured.

The machining control unit 11 sends a command (lens movement command) for moving the fθ lens 31 in the height direction (Z-axis direction) to the lens height control unit 14. The machining control unit 11 sends a lens movement command to the lens height control unit 14 when the workpiece W is laser processed.

The machining control unit 11 sends a command (camera movement command) for moving the camera 33 in the height direction to the camera height control unit 15. The machining control unit 11 sends a camera movement command to the camera height control unit 15 when positioning the workpiece W onto the XY table 35.

The machining control unit 11 is configured to be connectable to either one of the lens height control unit 14 and the camera height control unit 15. In other words, the machining control unit 11 performs switching between the control of the lens height control unit 14 and the control of the camera height control unit 15. Thereby, the machining control unit 11 performs one of height control (processing of sending a lens movement command) based on the fθ lens 31 or height control (processing of sending a camera movement command) based on the camera 33.

When the measurement sensor control unit 12 receives the altitude measurement command from the machining control unit 11, the height measurement sensor 32 measures the heights of the XY table 35 and the workpiece W. The height measuring sensor 32 is a sensor that measures the height of the XY table 35 and the workpiece W. The height measuring sensor 32 sends the measurement result (measurement signal) to the height data measuring unit 16.

The height data measuring unit 16 measures the heights of the XY table 35 and the workpiece W as height data based on the measurement results sent from the height measuring sensor 32. The height data measuring unit 16 sends the measured height data to the height control device 2.

When the table position control unit 13 receives the table movement command from the machining control unit 11, the XY table 35 sends a table movement instruction for moving the XY table 35 to a predetermined position in the XY plane. Further, the table position control unit 13 sends a table movement instruction to the height control device 2. The table position measuring unit 17 measures the position (coordinate) of the XY table 35 in the XY plane as the table position. The table position measuring unit 17 sends the measured table position to the height control device 2.

When the lens height control unit 14 receives the lens movement command from the processing control unit 11, an instruction to move the fθ lens 31 to a predetermined height (lens height command) is sent to the height control device 2. When the camera height control unit 15 receives the camera movement command from the processing control unit 11, the camera height control unit 15 sends an instruction to move the camera 33 to a predetermined height (a camera height control instruction). The Z-axis drive unit 34 is connected to the height control device 2 and moves in the Z-axis direction in accordance with an instruction from the height control device 2.

The height control device 2 includes a Z-axis correction data storage unit 21, a Z-axis correction coefficient calculation unit 22, a Z-axis correction position calculation unit 23, and a height control unit 24. Here, the Z-axis correction coefficient calculation unit 22 and the Z-axis correction position calculation unit 23 correspond to the calculation unit described in the patent application.

The Z-axis correction data storage unit 21 is a memory or the like connected to the height data measurement unit 16 and the table position measurement unit 17. The Z-axis correction data storage unit 21 stores the height data sent from the height data measurement unit 16 and memorizes the table position sent from the table position measurement unit 17. Before the laser processing of the workpiece W, the Z-axis correction data storage unit 21 stores information (the XY-Z correspondence information 101 to be described later) in which the height data and the table position are associated with each other. The XY-Z correspondence information 101 is information indicating the correspondence relationship between the height Z of the XY table 35 and the table position (X, Y).

The Z-axis correction coefficient calculation unit 22 calculates the unevenness of the XY table 35 using the XY-Z correspondence information 101 stored in the Z-axis correction data storage unit 21 before performing the laser processing of the workpiece W. Specifically, the Z-axis correction coefficient calculation unit 22 calculates a model expression (complementary) indicating the unevenness of the XY table 35 by performing polynomial approximation on the XY-Z correspondence information 101. In the present embodiment, the case where the Z-axis correction coefficient calculation unit 22 approximates the unevenness of the XY table 35 by the fourth-order polynomial will be described. The Z-axis correction coefficient calculation unit 22 holds the coefficient of the fourth-order polynomial indicating the unevenness of the XY table 35 as the Z-axis correction coefficient.

The Z-axis correction coefficient calculation unit 22 is configured to be connectable to any of the Z-axis correction position calculation unit 23 or the height control unit 24. The Z-axis correction coefficient calculation unit 22 is connected to the Z-axis correction position calculation unit 23 when performing laser processing of the workpiece W using the calculated model formula, and is connected to the height control unit 24 when the model formula is calculated. Switching destinations. When the Z-axis correction coefficient calculation unit 22 is connected to the Z-axis correction position calculation unit 23, the Z-axis correction coefficient is sent to the Z-axis correction position calculation unit 23.

The Z-axis correction position calculation unit 23 is connected to the camera height control unit 15, the lens height control unit 14, and the Z-axis correction coefficient calculation unit 22. The Z-axis correction position calculation unit 23 uses the lens height command sent from the lens height control unit 14 and the table movement instruction sent from the table position control unit 13 and the Z-axis sent from the Z-axis correction coefficient calculation unit 22. By correcting the coefficient, the corrected height command for the Z-axis drive unit 34 (the command for correcting the height of the lens height command) is calculated.

Specifically, the Z-axis correction position calculating unit 23 calculates the position (table position) of the XY table 35 corresponding to the table movement instruction, and calculates the thunder on the XY table 35 based on the position of the XY table 35. The location of the illumination. Further, the height of the irradiation position (X, Y) of the laser light is calculated using the correction coefficient of the fourth-order polynomial. Further, the difference between the calculated height and the height of the current position is calculated as the correction amount ΔZ (Z-axis correction position) (correction value). The Z-axis correction position calculation unit 23 calculates the corrected height command at the next machining position using the calculated correction amount ΔZ, the height correction amount Zbase at the reference position, and the lens height command. The Z-axis correction position calculation unit 23 sends the calculated corrected height command to the height control unit 24.

The height control unit 24 is connected to the Z-axis drive unit 34 to control the Z-axis drive unit 34. The height control unit 24 controls the height of the Z-axis driving unit 34 using the corrected height command sent from the Z-axis correction position calculating unit 23.

Next, an operation program of the laser processing apparatus 1 will be described. Here, a procedure for calculating the Z-axis correction coefficient of the operation program of the laser processing apparatus 1 will be described. Next, a correction processing procedure for performing the laser light irradiation position (height) at the time of laser processing will be described.

Fig. 3 is a flow chart showing a calculation procedure for calculating the Z-axis correction coefficient. When the Z-axis correction coefficient is calculated, the Z-axis correction coefficient calculation unit 22 is connected to the height control unit 24 in advance, and the height correction by the Z-axis correction position calculation unit 23 is invalidated. In the laser processing apparatus 1, the height measuring sensor 32 is moved to an arbitrary position (measurement point of the first point) on the XY table 35, and the height of the XY table 35 is measured (step S10). Specifically, the machining control unit 11 sends a table movement command to the table position control unit 13. When the table position control unit 13 receives the table movement command from the machining control unit 11, the table movement control instruction for moving the height measurement sensor 32 to the first point measurement point in the XY plane is sent to the XY table. 35 and height control device 2. The table position measuring unit 17 measures the position of the XY table 35 measured by the height measuring sensor 32 as a table position. The table position measuring unit 17 sends the measured table position to the height control device 2.

When the height measuring sensor 32 is moved to the first point measurement point in the XY plane, the machining control unit 11 sends a height measurement command for measuring the height of the workpiece W to the measurement sensor control unit 12. When the measurement sensor control unit 12 receives the altitude measurement command from the machining control unit 11, the height measurement sensor 32 measures the height of the XY table 35. Thereby, the height measuring sensor 32 measures the height of the XY table 35 and sends the measurement result to the height data measuring unit 16. The height data measuring unit 16 measures the height of the XY table 35 as height data based on the measurement result sent from the height measuring sensor 32 (step S20). The height data measuring unit 16 sends the recorded height data to the height control device 2. Thereby, the height data is associated with the table position of the first point, and the Z-axis correction data storage unit 21 memorizes it as XY-Z correspondence information (step S30).

Here, a measurement point for measuring the height of the XY table 35 on the XY table 35 will be described. Fig. 4 is a view for explaining a height measurement point set on the XY table 35. A plurality of measurement points P that are targets for height measurement are placed in advance on the XY table 35. The measurement point P is arranged, for example, at a predetermined interval in the X direction and the Y direction. In the fourth embodiment, the measurement point P is arranged at nine points in the X direction and eight points in the Y direction, and is arranged at equal intervals in the X direction and the Y direction.

The machining control unit 11 determines whether or not the height has been measured at all the measurement points P set in advance (step S40). If the height has not been measured at all the measurement points P (step S40, No), the machining control unit 11 moves the height measurement sensor 32 to an arbitrary position (next measurement point P) on the XY table 35, and measures the XY operation. The height of the stage 35 (step S10). Then, the height data is measured at the next measurement point P, and the information on which the table position of the measurement point P is associated with the height data is stored in the XY-Z correspondence information 101 in the Z-axis correction data storage unit 21 (step S30). .

The machining control unit 11 repeats the processes of steps S10 to S40 until the height is measured at all the measurement points P set in advance. Here, the XY-Z correspondence information 101 will be described. Fig. 5 is a view showing an example of XY-Z correspondence information. The XY-Z correspondence information 101 is an information worksheet in which the coordinates of the measurement point P and the height of the XY table 35 at the coordinate position are given. In Fig. 5, the X direction of the measurement point P on the XY table 35 is arranged at intervals of 90 mm in the manner of X = 0, 90, 180, 270, and Y = 0, 80, 160, 240 in the Y direction on the XY table 35. The case when the mode is arranged at intervals of 80 mm. In the XY-Z correspondence information 101, the coordinates of the measurement point P arranged in a lattice at predetermined intervals are given to the height of the corresponding XY table 35. In Fig. 5, (X, Y) = (0, 0) gives a corresponding height a, and (X, Y) = (90, 0) gives a corresponding height b.

When the height is measured at all the measurement points P (Yes in step S40), the Z-axis correction coefficient calculation unit 22 divides the area 4 on the XY table 35. Thereby, the data 4 of the XY-Z correspondence information 101 stored in the Z-axis correction data storage unit 21 is divided. In other words, the Z-axis correction coefficient calculation unit 22 assigns the measurement points P of the measurement height to the four groups corresponding to the regions on the XY table 35 (step S50).

Fig. 6 is a view for explaining area division of the XY table. As shown in Fig. 6, four regions are set on the XY table 35 by dividing the region on the XY table 35 as the regions A1 to D1. Fig. 6 shows a case where the region on the XY table 35 is divided into two in the X direction and divided in the Y direction. In other words, the region 4 on the XY table 35 is divided by a line parallel to the X axis and a line parallel to the Y axis. When the intersection between the line parallel to the X-axis and the line parallel to the Y-axis which divides the area on the XY table 35 is taken as the origin, the area corresponding to the first quadrant is the area B1, which corresponds to the second quadrant. The area is area A1. Further, the region corresponding to the third quadrant is the region C1, and the region corresponding to the fourth quadrant is the region D1.

Further, the area setting on the XY table 35 is not limited to the area division of the XY table 35. For example, each area may be set in such a manner that a part of the area after the area setting is overlapped with other areas. Fig. 7 is a view for explaining an area setting when a part of the areas overlap with each other. Fig. 7 shows a case where the areas A2 to D2 after the areas A1 to D1 are expanded by overlapping with other areas in the predetermined area, respectively, are set on the XY table 35.

The region A2 is a region in which the region A1 is enlarged in the X-axis direction and the Y-axis direction, and the region B2 is a region in which the region B1 is enlarged in the X-axis direction and the Y-axis direction. Further, the region C2 is a region in which the region C1 is enlarged in the X-axis direction and the Y-axis direction, and the region D2 is a region in which the region D1 is enlarged in the X-axis direction and the Y-axis direction. Thereby, the regions A2 to D2 are only partially overlapped with other regions.

The Z-axis correction coefficient calculation unit 22 calculates a Z-axis correction coefficient for each divided region. The Z-axis correction coefficient calculation unit 22 models the unevenness (height) of the XY table 35 by polynomial approximation by the least square method or the like. For example, the Z-axis correction coefficient calculation unit 22 approximates the height Z of the XY table 35 by the formula (1).

Z=a+bY+cY ² +dY ³ +eY ⁴ +fX+gXY+hXY ² +iXY ³ +jX ² +kX ² Y+1X ² Y ² +mX ³ +nX ³ Y+oX ⁴ (1)

The Z-axis correction coefficient calculation unit 22 calculates the Z-axis correction coefficient for each region by calculating the coefficient of the equation (1) (step S60). The Z-axis correction coefficient calculation unit 22 stores the calculated Z-axis correction coefficient in association with each region.

Further, when the areas A2 to D2 are set in the XY table 35, the fields in which the plurality of areas are set (for example, the area in which the area A2 and the area B2 overlap) are selected by the selected area, and the selected one is applied. The Z-axis correction factor for the zone. Further, in a field in which a plurality of regions are set, a plurality of regions may be selected from the set regions, and the Z-axis correction coefficients of the selected regions may be all applied. At this time, the height average value or the like calculated using the respective Z-axis correction coefficients of the respective regions will be the height of the XY table 35.

Next, a correction processing procedure for the laser light irradiation position (height) at the time of laser processing will be described. Fig. 8 is a flow chart showing a procedure for correcting the height of the irradiated laser light. The workpiece W is placed on the XY table 35 before the laser processing is started. Thereafter, the laser processing apparatus 1 moves the altimeter sensor 32 to the coordinates in the XY plane set on the XY table 35 at the height reference position, and measures the height of the workpiece W on the XY table 35 (becomes the reference). the height of). The coordinates in the XY plane which becomes the height reference position may be any position on the workpiece W, and may be, for example, a position other than the machined hole.

When the height of the workpiece W is measured, the Z-axis correction coefficient calculation unit 22 is connected to the height control unit 24 in advance, and the height correction by the Z-axis correction position calculation unit 23 is invalidated. Thereafter, the machining control unit 11 sends a table movement command to the table position control unit 13. When the table position control unit 13 receives the table movement command from the machining control unit 11, the table movement instruction for moving the height measurement sensor 32 to the height reference position measurement point is sent to the XY table 35. The table position measuring unit 17 measures the position of the XY table 35 measured by the height measuring sensor 32 as the table position. The table position measuring unit 17 sends the measured table position to the height control device 2.

When the height measuring sensor 32 is moved to the reference position measurement point in the XY plane, the machining control unit 11 sends a height measurement command for measuring the height of the workpiece W to the measurement sensor control unit 12. When the measurement sensor control unit 12 receives the altitude measurement command from the machining control unit 11, the height measurement sensor 32 measures the height of the XY table 35. Thereby, the height measuring sensor 32 measures the height signal corresponding to the height of the workpiece W and sends the measurement result to the height data measuring unit 16. The height data measuring unit 16 measures the height of the workpiece W at the reference position based on the measurement result sent from the height measuring sensor 32. The height data measuring unit 16 sends the measured height to the height control device 2 as height data.

The height data measured by the height data measuring unit 16 and the table position measured by the table position measuring unit 17 are stored in the Z-axis correction data storage unit 21. The Z-axis correction coefficient calculation unit 22 calculates an offset value of the height calculated using the Z-axis correction coefficient (model formula). The offset value is a height corresponding to the thickness of the workpiece W, and the shift is calculated by the model to a height up to the offset value. Specifically, the Z-axis correction coefficient calculation unit 22 calculates the height at the reference position using the table position and the model expression at the reference position, and uses the height and height data measuring unit 16 measured at the calculated reference position. The correction data Zbase whose height is the offset value of the height is calculated (step S110).

After that, the Z-axis correction coefficient calculation unit 22 is connected to the Z-axis correction position calculation unit 23, and the height correction obtained by the Z-axis correction position calculation unit 23 is validated. Further, the processing control unit 11 is connected to the lens height control unit 14.

Thereafter, the laser processing apparatus 1 starts the laser processing at the first point. The machining control unit 11 inputs the movement command (X1, Y1, Z1) corresponding to the machining position of the first point to the lens height control unit 14 and the table position control unit 13 (step S120). Specifically, the machining control unit 11 sends the lens movement command to the lens height control unit 14 and sends the table movement command to the table position control unit 13.

When the lens height control unit 14 receives the lens movement command from the processing control unit 11, the lens height command Z1 for moving the height of the fθ lens 31 to the laser light irradiation position is sent to the Z-axis correction position calculating unit 23. Here, the lens height command Z1 indicates that the XY table 35 is flat and the workpiece W is not placed, and the indication information indicating the height of the fθ lens 31 that can irradiate the laser light on the XY table 35 with the best focus is specified.

When the table position control unit 13 receives the table movement command from the machining control unit 11, the table position control unit 13 sends a table movement instruction for moving the fθ lens 31 to the first point machining position to the XY table 35. Thereby, the XY table 35 is moved to the first processing position. Specifically, the XY table 35 is moved such that the fθ lens 31 is moved toward the first processing position on the workpiece W.

Further, the table position control unit 13 sends a table movement instruction corresponding to the first point machining position to the Z-axis correction position calculating unit 23. The Z-axis correction position calculation unit 23 calculates the difference between the height of the first point machining position and the height of the reference position as the correction amount ΔZ1 of the movement destination using the model formula calculated by the Z-axis correction coefficient calculation unit 22 (step S130). ). The correction amount ΔZ1 referred to here is when the height at the first machining position is Z1, and when the height of the reference position is Z0, ΔZ1 = Z1 - Z0.

After that, the Z-axis correction position calculating unit 23 calculates the corrected height command at the time of performing the first point machining using the model formula. Specifically, when the corrected height command is Zz1, the corrected height command Zz1 is calculated by the equation (2) (step S140).

Zz1=Z1+ΔZ1-Zbase ...(2)

The Z-axis correction position calculation unit 23 sends the calculated corrected height command Zz1 to the height control unit 24, and the height control unit 24 controls the Z-axis drive unit 34 using the corrected height command Zz1. Thereby, the fθ lens 31 is moved to the position (X1, Y1, Zz1) obtained by correcting the movement command (X1, Y1, Z1) from the machining control unit 11 (step S150). Further, the laser processing apparatus 1 performs laser processing at the first point (step S160).

The machining control unit 11 determines whether or not all the machining points have been processed (step S170). If all the machining points have not been processed (step S170, No), the laser processing apparatus 1 starts the processing of the second point (step S180).

The machining control unit 11 inputs the movement command (X2, Y2, Z2) corresponding to the machining position of the second point to the lens height control unit 14 and the table position control unit 13 (step S120). Specifically, the machining control unit 11 sends the lens movement command to the lens height control unit 14 and sends the table movement command to the table position control unit 13.

When the lens height control unit 14 receives the lens movement command from the processing control unit 11, the lens height command Z2 for moving the height of the fθ lens 31 to the laser light irradiation position is sent to the Z-axis correction position calculating unit 23. Here, the lens height command Z2 is the same height as the lens height command Z1 when the first point processing is performed.

When the table position control unit 13 receives the table movement command from the machining control unit 11, the table position control unit 13 sends a table movement instruction to move the fθ lens 31 to the processing position of the second point to the XY table 35. Thereby, the XY table 35 is moved to the processing position of the second point. Specifically, the XY table 35 is moved such that the fθ lens 31 reaches the second processing position on the workpiece W.

Further, the table position control unit 13 sends a table movement instruction corresponding to the second point machining position to the Z-axis correction position calculating unit 23. The Z-axis correction position calculation unit 23 calculates the difference between the height at the second machining position and the height at the first machining position as the correction amount of the movement destination using the model formula calculated by the Z-axis correction coefficient calculation unit 22 . ΔZ2 (step S130). The correction amount ΔZ2 referred to here is ΔZ2=Z2-Z1 when the height of the second processing position is Z1.

After that, the Z-axis correction position calculating unit 23 calculates the corrected height command at the time of performing the second point machining using the model formula. Specifically, when the corrected height command is Zz2, the corrected height command Zz2 is calculated by the equation (3) (step S140).

Zz2=Z2+ΔZ2-Zbase...(3)

Z2 of the formula (3) is a post-correction height command Zz1 when the first point is processed. Therefore, the corrected height command Zz2 at the second point is calculated by the equation (4).

Zz2=Zz1+ΔZ2-Zbase...(4)

The Z-axis correction position calculation unit 23 sends the calculated corrected height command Zz2 to the height control unit 24, and the height control unit 24 controls the Z-axis drive unit 34 using the corrected height command Zz2. Thereby, the fθ lens 31 is moved to the position (X2, Y2, Zz2) obtained by correcting the movement command (X2, Y2, Z2) from the machining control unit 11 (step S150). Further, the laser processing apparatus 1 performs laser processing at the second point (step S160).

Fig. 9 is a view for explaining the correction amount and correction data at the movement destination. As shown in Fig. 9, the difference between the height Z0 at the reference position and the height Z1 at the first machining position is ΔZ1, and the height Z1 at the first machining position and the height Z2 at the second machining position. The difference is ΔZ2. As described above, the height at each processing point can be represented by the difference from the height of the previous processing point. In the present embodiment, the height difference ΔZ1, ΔZ2, and the like are calculated by a model formula, and the corrected height command is calculated using ΔZ1, ΔZ2, or the like. In addition, when calculating the corrected height command, the height displacement correction data Zbase amount calculated by the model formula is used.

The machining control unit 11 determines whether or not all the machining points have been processed (step S170). The laser processing apparatus 1 repeats the processing of steps S120 to S180 until all the processing points are processed.

When the nth (n is a natural number) point is processed, the Z-axis correction position calculating unit 23 calculates the height at the n-th processing position and the first (the) using the model equation calculated by the Z-axis correction coefficient calculation unit 22. N-1) The difference between the heights of the point machining positions is the correction amount ΔZn of the movement destination. At this time, the correction amount ΔZn is Zn at the processing position at the nth point, and ΔZn=Zn-Z when the height at the (n-1)th processing position is Z(n-1). 1).

Further, the Z-axis correction position calculating unit 23 calculates a corrected height command when the n-th point is processed using the model formula. Specifically, when the corrected height command is Zzn, the corrected height command Zzn is calculated by the equation (5).

Zzn=Zz(n-1)+ΔZn-Zbase...(5)

When all the machining points are processed (step S170, Yes), the laser processing apparatus 1 ends the laser processing for the workpiece W. Thereafter, the processing of steps S110 to S180 is repeated when the next workpiece W is processed.

As described above, in the present embodiment, the amount of unevenness on the surface of the XY table 35 is calculated using a model formula. Thereafter, when a movement command below the table position is generated, the amount of unevenness of the movement destination is calculated based on the model formula and the difference from the height before the movement is calculated. Thereafter, when the table is moved, the irradiation position of the laser light is moved in the height direction by the calculated difference amount. Thereby, the height of the processing position of the workpiece W can be corrected along the concave-convex model of the XY table 35.

Further, in the present embodiment, the case where the unevenness of the XY table 35 is approximated by the fourth-order polynomial is described as an example, but it may be a polynomial of less than four times or a polynomial of five or more times. The bump of the XY table 35 is approximated.

Further, in the present embodiment, the case where the model is calculated by the laser processing apparatus 1 will be described as an example, but the model may be calculated by another device. At this time, the laser processing apparatus 1 calculates the corrected height command Zzn using the model equation calculated by another apparatus.

In the present embodiment, the case where the region 4 on the XY table 35 is divided and the Z-axis correction coefficient is calculated for each region will be described as an example. However, the region division is not limited to four divisions. For example, the area on the XY table 35 may be divided into two, three, or five or more. Further, the Z-axis correction coefficient may be calculated without dividing the area on the XY table 35.

According to the above embodiment, since the approximation is performed using a polynomial, only a small amount of data (correction coefficient) for calculating the unevenness of the XY table 35 is required. Thus, the amount of data to be stored is small.

Further, since the Z-axis correction coefficient is calculated for each region by dividing the region on the XY table 35, the unevenness of the XY table 35 can be accurately approximated. Further, since the regions are set on the XY table 35 so that the regions A2 to D2 partially overlap with one of the other regions, the approximation can be accurately performed even in the vicinity of the boundary.

(industrial availability)

As described above, the laser processing apparatus and the laser processing method of the present invention are suitable for laser processing of a workpiece placed on an XY table.

1. . . Laser processing device

2. . . Height control device

11. . . Processing control department

12. . . Measurement sensor control unit

13. . . Workbench position control

14. . . Lens height control

15. . . Camera height control

16. . . Height data measurement department

17. . . Workbench position measurement unit

twenty one. . . Z axis correction data memory

twenty two. . . Z-axis correction coefficient calculation unit

twenty three. . . Z-axis correction position calculation unit

twenty four. . . Height control department

30. . . laser

31. . . Fθ lens

32. . . Height measuring sensor

33. . . camera

34. . . Z-axis drive unit

35. . . XY table

101. . . XY-Z correspondence information

A1 to D1, A2 to D2. . . region

W. . . Machining

Fig. 1 is a view showing a laser processing apparatus according to an embodiment.

Fig. 2 is a functional block diagram showing the configuration of a laser processing apparatus.

Fig. 3 is a flow chart showing a calculation procedure for calculating the Z-axis correction coefficient.

Fig. 4 is a view for explaining a height measurement point set on the XY table.

Fig. 5 is a view showing an example of information corresponding to XY-Z.

Fig. 6 is a view for explaining area division of the XY table.

Fig. 7 is a view for explaining an area setting when a region has a part overlapping each other.

Fig. 8 is a flow chart showing a correction processing procedure for irradiating the height of the laser light.

Fig. 9 is a view for explaining the correction amount and correction data at the movement destination.

1. . . Laser processing device

2. . . Height control device

11. . . Processing control department

12. . . Measurement sensor control unit

13. . . Workbench position control

14. . . Lens height control

15. . . Camera height control

16. . . Height data measurement department

17. . . Workbench position measurement unit

twenty one. . . Z axis correction data memory

twenty two. . . Z-axis correction coefficient calculation unit

twenty three. . . Z-axis correction position calculation unit

twenty four. . . Height control department

32. . . Height measuring sensor

34. . . Z-axis drive unit

35. . . XY table

Claims (5)

A laser processing apparatus that performs laser processing on a workpiece by irradiating laser light onto a workpiece placed on an XY table, wherein the laser beam irradiation unit moves to a predetermined position on the workpiece The workpiece is irradiated with the laser beam at a height; and the calculation unit calculates the height of the laser beam irradiation unit at each processing position on the workpiece using the approximation formula (1) in which the surface height of the XY table is modeled. And correcting the value, and correcting the processed height after the processing of the processed object by the correction value to calculate the corrected processing height; and driving the portion to move the laser light irradiation unit to the processing height after the correction ;Z=a+bY+cY ² +dY ³ +eY ⁴ +fX+gXY+hXY ² +iXY ³ +jX ² +kX ² Y+lX ² Y ² +mX ³ +nX ³ Y+oX ⁴ (1 ). The laser processing apparatus according to claim 1, further comprising: a height measuring unit that measures a height of the XY table; wherein the calculating unit is based on the XY table at a plurality of points measured by the height measuring unit The approximate expression is calculated from the surface height. The laser processing apparatus according to claim 2, wherein the calculation unit sets a plurality of regions on the XY table, and calculates the approximate expression for each region. The laser processing apparatus according to claim 3, wherein the calculation unit overlaps a portion of the adjacent regions The mode sets the aforementioned area. A laser processing method for performing laser processing on a workpiece by irradiating laser light onto a workpiece placed on an XY table, wherein the method includes a correction value calculation step of moving the workpiece to The height correction value of the laser beam irradiation unit that irradiates the laser beam with the predetermined height is calculated by using the approximation formula (1) in which the surface height of the XY table is modeled on each of the processing positions on the workpiece; a height calculation step of calculating a corrected machining height by correcting the instructed machining height with the correction value when the machining of the workpiece is processed, and a machining step of moving the laser beam irradiation unit to the corrected machining height Perform laser processing; Z=a+bY+cY ² +dY ³ +eY ⁴ +fX+gXY+hXY ² +iXY ³ +jX ² +kX ² Y+lX ² Y ² +mX ³ +nX ³ Y+oX ⁴ ... (1).