Laser processing equipment

Abstract

To provide a laser processing device that is able to shorten downtime by reducing an adjustment work, while suppressing deterioration in processing quality resulting from a difference in converging position.SOLUTION: A laser processing device 1 comprises a control unit 90 including: a storage unit 91 that, based on an amount of displacement between a center line of a first groove formed by converging a laser beam 21 at a position of a first height using an upper surface 101 of a work piece 100 as a reference and a center line of a second groove formed by converging a laser beam 21 at a position of a second height different from the first height, stores a correlation between a height position of a converging point of the laser beam 21 and the amount of displacement; a calculation unit 92 that, based on the correlation stored in the storage unit 91, estimates and calculates an amount of displacement of a processed groove formed when the converging point is located at the position of the height; and a correction unit 93 that, when processing is performed with the converging point located at the position of the predetermined height, corrects a horizontal position of the converging point so as to cancel out the amount deviation calculated by the calculation unit 92.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laser processing apparatus. [Background technology]

[0002] In order to manufacture chips by dividing a workpiece such as a semiconductor wafer, a laser processing device is used that irradiates a laser beam onto the workpiece to form a processing groove (see Patent Document 1). Generally, a laser processing device is configured so that a laser beam propagated from a mounted laser oscillator through various optical components such as mirrors and lenses is focused by a focusing lens onto a processing point where the workpiece is processed.

[0003] If the laser beam is incident on the focusing lens with a deviation or tilt, various problems may occur, such as the machining groove being formed at an angle, or debris scattered during machining being formed on one side of the machining groove. Therefore, the optical axis of the laser beam needs to be adjusted to minimize the angle and positional deviation, and the focal position is offset to adjust the positional deviation of the machining mark when machining the workpiece so that it falls within a predetermined tolerance range (see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-275912 A [Patent Document 2] JP 2020-196038 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, there is a processing method in which a pair of processing lines is formed in a street with the light focused on the surface of the workpiece (just focused), and then the processing between the pair of processing lines is performed with the light focused position offset (defocused), thereby reducing the number of passes while suppressing film peeling. When using this processing method, the amount of positional deviation of the processing marks is adjusted to a minimum by the method described in Patent Document 2, but positional deviation occurs within the range of the allowable value, and there are cases in which it is not possible to completely suppress the occurrence of delamination due to the positional deviation between the processing marks at both ends and the processing mark in the center.

[0006] Therefore, currently, an operator checks the amount of positional deviation of the processing marks at the focusing position when processing a workpiece, and sets the control unit to correct the confirmed amount of deviation. However, this method is cumbersome because it requires confirmation each time processing is performed at a different focusing position.

[0007] The present invention has been made in consideration of such problems, and its purpose is to provide a laser processing apparatus that can reduce adjustment work and shorten downtime while suppressing deterioration in processing quality caused by differences in the focusing position. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the laser processing apparatus of the present invention includes a chuck table for holding a workpiece, a laser beam application unit having a condensing lens for condensing and irradiating a laser beam onto the workpiece held on the chuck table, a processing feed unit for relatively moving the chuck table and the condensing point of the laser beam in a processing feed direction, an indexing feed unit for relatively moving the chuck table and the condensing point of the laser beam in an indexing feed direction perpendicular to the processing feed direction, a condensing point position adjustment unit for adjusting the height position of the condensing point by moving the condensing lens in a direction perpendicular to a holding surface of the chuck table, an imaging unit for imaging the workpiece, a display unit for displaying an image captured by the imaging unit, and a control unit, and the control unit is configured to focus the laser beam at a position of a first height based on an upper surface of the workpiece to form a mark on the workpiece. Along the processing feed direction The first groove is formed on the workpiece by converging the laser beam at a position of a second height different from the first height based on the center line of the first groove in a first image obtained by imaging the first groove and the top surface of the workpiece. Along the processing feed direction A center line of the second groove in a second image obtained by imaging the second groove; and In the index feed direction A memory unit that stores a correlation between the height position of the focal point of the laser beam and the amount of deviation based on the amount of deviation, and a machining groove that is formed when the focal point is positioned at a predetermined height position based on the correlation stored in the memory unit. In the index feed direction A calculation unit that predicts and calculates the amount of deviation, and the amount of deviation calculated by the calculation unit when processing is performed in a state in which the light condensing point is positioned at the predetermined height position. The coordinate position where the sign is inverted in the index feed direction The horizontal position of the focal point is Automatically and a correction unit for correcting the difference. Effect of the Invention

[0009] The present invention can reduce downtime by reducing adjustment work while suppressing deterioration in processing quality caused by differences in the focusing position. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing an example of the configuration of a laser processing device according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a first example of an adjustment state of the optical axis of a laser beam. [Diagram 3] FIG. 3 is a plan view showing an example of a processing state by a laser beam in the adjustment state shown in FIG. [Figure 4] FIG. 4 is a schematic diagram showing a second example of the adjustment state of the optical axis of the laser beam. [Diagram 5] FIG. 5 is a plan view showing an example of a processing state by the laser beam in the adjustment state shown in FIG. [Figure 6] FIG. 6 is a schematic diagram showing a third example of an adjustment state of the optical axis of a laser beam. [Figure 7] FIG. 7 is a plan view showing an example of a processing state by the laser beam in the adjustment state shown in FIG. [Figure 8] FIG. 8 is a diagram showing a first image obtained by imaging the first groove. [Figure 9] FIG. 9 is a diagram showing a second image obtained by imaging the second groove. [Figure 10] FIG. 10 is a diagram showing a third image obtained by imaging the third groove. [Figure 11] FIG. 11 is a diagram showing an example of the relationship between the height position of the light-collecting point and the amount of deviation in the horizontal direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. Furthermore, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the gist of the present invention.

[0012] [Embodiment] First, the configuration of a laser processing device 1 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of the configuration of a laser processing device 1 according to an embodiment. In the following description, the X-axis direction is one direction on a horizontal plane. The Y-axis direction is a direction perpendicular to the X-axis direction on a horizontal plane. The Z-axis direction is a direction perpendicular to the X-axis direction and the Y-axis direction. The Z-axis direction is a direction perpendicular to the X-axis direction and the Y-axis direction. In the laser processing device 1 of the embodiment, the processing feed direction is the X-axis direction, and the indexing feed direction is the Y-axis direction.

[0013] 1, the laser processing apparatus 1 includes a chuck table 10, a laser beam irradiation unit 20, a processing feed unit 40, an indexing feed unit 50, a focal point position adjustment unit 60, an imaging unit 70, a display unit 80, and a control unit 90. The laser processing apparatus 1 according to the embodiment is an apparatus for processing the workpiece 100 by irradiating the workpiece 100 held on the chuck table 10 with a laser beam 21 by the laser beam irradiation unit 20. The processing of the workpiece 100 by the laser processing apparatus 1 is, for example, groove processing for forming grooves on the surface of the workpiece 100, or cutting processing for cutting the workpiece 100 along a planned division line.

[0014] In the embodiment, the workpiece 100 is a disk-shaped semiconductor device wafer, an optical device wafer, or other wafer having a substrate of silicon (Si), sapphire (Al2O3), gallium arsenide (GaAs), silicon carbide (SiC), lithium tantalate (LiTa3), or the like, and is a dummy wafer for verification processing. Note that the workpiece 100 is not limited to the embodiment, and does not have to be disk-shaped in the present invention. The workpiece 100 is supported within an opening of the annular frame 110, for example, with an annular frame 110 attached and a tape 111 having a diameter larger than the outer diameter of the workpiece 100 attached to the back surface of the workpiece 100.

[0015] The chuck table 10 holds the workpiece 100 on a holding surface 11. The holding surface 11 is a disk shape made of porous ceramics or the like. In the embodiment, the holding surface 11 is a plane parallel to the horizontal direction. The holding surface 11 is connected to a vacuum suction source, for example, via a vacuum suction path. The chuck table 10 holds the workpiece 100 placed on the holding surface 11 by suction. A plurality of clamps 12 are arranged around the chuck table 10 to clamp an annular frame 110 that supports the workpiece 100.

[0016] The chuck table 10 is rotated about an axis parallel to the Z-axis direction by a rotation unit 13. The rotation unit 13 is supported by an X-axis direction moving plate 14. The rotation unit 13 and the chuck table 10 are moved in the X-axis direction by a processing feed unit 40 via the X-axis direction moving plate 14. The rotation unit 13 and the chuck table 10 are moved in the Y-axis direction by an indexing feed unit 50 via the X-axis direction moving plate 14, the processing feed unit 40, and the Y-axis direction moving plate 15.

[0017] The laser beam irradiation unit 20 is a unit that irradiates the workpiece 100 held on the chuck table 10 with a pulsed laser beam 21 having a predetermined wavelength for processing the workpiece 100. The laser beam irradiation unit 20 includes, for example, a laser oscillator that oscillates the laser beam 21, a condenser lens 22 (see FIGS. 2, 4, and 6), and various optical components that are provided on the optical path of the laser beam 21 between the laser oscillator and the condenser lens 22. The condenser lens 22 condenses the laser beam 21 oscillated from the laser oscillator and propagated by the various optical components onto the workpiece 100 held on the holding surface 11 of the chuck table 10, and irradiates the workpiece 100.

[0018] The processing feed unit 40 is a unit that relatively moves the chuck table 10 and the laser beam irradiation unit 20 in the X-axis direction, which is the processing feed direction. In the embodiment, the processing feed unit 40 moves the chuck table 10 in the X-axis direction. In the embodiment, the processing feed unit 40 is installed on the device body 2 of the laser processing device 1.

[0019] The processing feed unit 40 supports the X-axis moving plate 14 so as to be movable in the X-axis direction. The processing feed unit 40 includes a well-known ball screw 41, a well-known pulse motor 42, and a well-known guide rail 43. The ball screw 41 is provided so as to be rotatable about its axis. The pulse motor 42 rotates the ball screw 41 about its axis. The guide rail 43 supports the X-axis moving plate 14 so as to be movably in the X-axis direction. The guide rail 43 is provided and fixed to the Y-axis moving plate 15.

[0020] The indexing feed unit 50 is a unit that relatively moves the chuck table 10 and the laser beam irradiation unit 20 in the Y-axis direction, which is the indexing feed direction. In the embodiment, the indexing feed unit 50 moves the chuck table 10 in the Y-axis direction. In the embodiment, the indexing feed unit 50 is installed on the device body 2 of the laser processing device 1.

[0021] The indexing feed unit 50 supports the Y-axis moving plate 15 so as to be movable in the Y-axis direction. The indexing feed unit 50 includes a well-known ball screw 51, a well-known pulse motor 52, and a well-known guide rail 53. The ball screw 51 is provided so as to be rotatable about its axis. The pulse motor 52 rotates the ball screw 51 about its axis. The guide rail 53 supports the Y-axis moving plate 15 so as to be movably in the Y-axis direction. The guide rail 53 is provided and fixed to the device body 2.

[0022] The focal point position adjustment unit 60 is a unit that moves the focal point 23 (see FIGS. 2, 4 and 6) of the laser beam 21 focused by the focusing lens 22 (see FIGS. 2, 4 and 6) of the laser beam irradiating unit 20 in the optical axis direction perpendicular to the holding surface 11 of the chuck table 10, and adjusts the height position of the focal point 23. More specifically, the focal point position adjustment unit 60 relatively moves the chuck table 10 and the laser beam irradiating unit 20 in the Z-axis direction, which is the focal point position adjustment direction. In the embodiment, the focal point position adjustment unit 60 moves at least the focusing lens 22 of the laser beam irradiating unit 20 in the Z-axis direction. In the embodiment, the focal point position adjustment unit 60 is installed on a pillar 3 erected from the device body 2 of the laser processing device 1.

[0023] The focal point position adjustment unit 60 supports at least the focusing lens 22 (see Figures 2, 4 and 6) of the laser beam irradiation unit 20 so as to be movable in the Z-axis direction. The focal point position adjustment unit 60 includes a well-known ball screw 61, a well-known pulse motor 62, and a well-known guide rail 63. The ball screw 61 is provided so as to be rotatable about its axis. The pulse motor 62 rotates the ball screw 61 about its axis. The guide rail 63 supports the laser beam irradiation unit 20 so as to be movably in the Z-axis direction. The guide rail 63 is provided and fixed to the pillar 3.

[0024] The imaging unit 70 images the workpiece 100 held on the chuck table 10. The imaging unit 70 includes a CCD (Charge Coupled Device) camera or an infrared camera that images the workpiece 100 held on the chuck table 10. The imaging unit 70 is fixed, for example, adjacent to the condenser lens 22 (see FIGS. 2, 4, and 6) of the laser beam irradiation unit 20. The imaging unit 70 images the workpiece 100 to obtain an image for performing alignment between the workpiece 100 and the laser beam irradiation unit 20, and outputs the obtained image to the control unit 90.

[0025] The display unit 80 is a display section configured by a liquid crystal display device or the like. The display unit 80 displays, for example, a setting screen for processing conditions, the state of the workpiece 100 captured by the imaging unit 70, the state of the processing operation, and the like on the display surface. When the display surface of the display unit 80 includes a touch panel, the display unit 80 may include an input unit. The input unit can receive various operations such as an operator registering processing content information. The input unit may be an external input device such as a keyboard. The display unit 80 switches information and images displayed on the display surface by operations from the input unit or the like. The display unit 80 may include an alarm device. The alarm device emits at least one of sound and light to notify the operator of the laser processing device 1 of predetermined alarm information. The alarm device may be an external alarm device such as a speaker or a light-emitting device.

[0026] The control unit 90 controls each of the above-mentioned components of the laser processing apparatus 1, and causes the laser processing apparatus 1 to execute a processing operation on the workpiece 100. The control unit 90 controls the laser beam irradiation unit 20, the processing feed unit 40, the indexing feed unit 50, the focal point position adjustment unit 60, the imaging unit 70, and the display unit 80. The control unit 90 is a computer including an arithmetic processing device as a calculation means, a storage device as a storage means, and an input / output interface device as a communication means. The arithmetic processing device includes, for example, a microprocessor such as a CPU (Central Processing Unit). The storage device has a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory). The arithmetic processing device performs various calculations based on a predetermined program stored in the storage device. The arithmetic processing device outputs various control signals to each of the above-mentioned components via the input / output interface device according to the calculation results, and controls the laser processing apparatus 1.

[0027] The control unit 90, for example, causes the imaging unit 70 to capture an image of the workpiece 100. The control unit 90, for example, performs image processing of the image captured by the imaging unit 70. The control unit 90, for example, detects a processing line of the workpiece 100 by image processing. The control unit 90, for example, drives the processing feed unit 40 so that the processing point, which is the focal point 23 (see Figs. 2, 4, and 6) of the laser beam 21, moves along the processing line, and causes the laser beam irradiation unit 20 to irradiate the laser beam 21. The control unit 90 includes a memory unit 91, a calculation unit 92, and a correction unit 93. The functions of the memory unit 91, the calculation unit 92, and the correction unit 93 of the control unit 90 will be described later.

[0028] Next, the adjustment state of the optical axis 24 of the laser beam 21 and the difference in the machining state due to the difference in the height position of the focal point 23 will be described. FIG. 2 is a schematic diagram showing a first example of the adjustment state of the optical axis 24 of the laser beam 21. FIG. 3 is a plan view showing an example of the machining state by the laser beam 21 in the adjustment state shown in FIG. 2. FIG. 4 is a schematic diagram showing a second example of the adjustment state of the optical axis 24 of the laser beam 21. FIG. 5 is a plan view showing an example of the machining state by the laser beam 21 in the adjustment state shown in FIG. 4. FIG. 6 is a schematic diagram showing a third example of the adjustment state of the optical axis 24 of the laser beam 21. FIG. 7 is a plan view showing an example of the machining state by the laser beam 21 in the adjustment state shown in FIG. 6.

[0029] 3, 5 and 7 show a pair of first processing lines 120 formed on the upper surface 101 of the workpiece 100 and a second processing line 121 formed between the first processing lines 120. The first processing line 120 is formed in a state where the height position of the focal point 23 of the laser beam 21 is adjusted to the upper surface 101 of the workpiece 100, that is, in a state where the defocus is 0 μm (just focus). The processing width (width in the Y-axis direction) of the first processing line 120 formed in a state where the defocus is 0 μm (just focus) is about 5 μm or more and 15 μm or less. The second processing line 121 is formed between the pair of first processing lines 120 in a state where the height position of the focal point 23 is offset by a predetermined amount (for example, +300 μm) after the first processing line 120 is formed. The processing width of the second processing line 121 formed in a state where the defocus is +300 μm is about 20 μm or more and 50 μm or less.

[0030] 2, in the adjusted state of optical axis 24 of laser beam 21 in the first example, optical axis 24 is incident on the center of condenser lens 22. In this case, optical axis 25 of laser beam 21 that has passed through condenser lens 22 is parallel to the Z-axis direction, i.e., travels straight. Therefore, even if the height position of condenser point 23 is offset, optical axis 25 of laser beam 21 that has passed through condenser lens 22 does not shift in the horizontal direction (XY plane direction) with respect to condenser point 23.

[0031] That is, in the first example adjustment state shown in Fig. 2, the center in the Y-axis direction of the laser beam 21 is fixed, so even if the focusing point 23 is offset in the Z-axis direction from the processing point, the center in the Y-axis direction of the processing mark does not shift. Therefore, in the processing state by the laser beam 21 in the adjustment state shown in Fig. 2, a second processing line 121 is formed along the center between a pair of first processing lines 120, as shown in Fig. 3.

[0032] 4, in the adjusted state of optical axis 24 of laser beam 21 in the second example, optical axis 24 is incident on a position shifted in the -Y direction with respect to the center of condenser lens 22. In this case, optical axis 25 of laser beam 21 that has passed through condenser lens 22 is tilted in the +Y direction with respect to the Z-axis direction. Therefore, when the height position of condenser point 23 is offset, optical axis 25 of laser beam 21 that has passed through condenser lens 22 is shifted in the -Y direction with respect to condenser point 23 above condenser point 23, and is shifted in the +Y direction with respect to condenser point 23 below condenser point 23.

[0033] That is, in the second example adjustment state shown in Fig. 4, the Y-axis direction center of the laser beam 21 moves from the -Y direction to the +Y direction as it advances in the -Z direction, so if the focusing point 23 is offset in the Z direction from the processing point, the Y-axis direction center of the processing mark will shift. Therefore, in the processing state by the laser beam 21 in the adjustment state shown in Fig. 4, a second processing line 121 is formed at a position shifted in the -Y direction from the center between a pair of first processing lines 120, as shown in Fig. 5.

[0034] 6, in the adjusted state of optical axis 24 of laser beam 21 in the third example, optical axis 24 is incident on a position shifted in the +Y direction with respect to the center of condenser lens 22. In this case, optical axis 25 of laser beam 21 that has passed through condenser lens 22 is tilted in the -Y direction with respect to the Z-axis direction. Therefore, when the height position of condenser point 23 is offset, optical axis 25 of laser beam 21 that has passed through condenser lens 22 is shifted in the +Y direction with respect to condenser point 23 above condenser point 23, and is shifted in the -Y direction with respect to condenser point 23 below condenser point 23.

[0035] That is, in the adjustment state of the third example shown in Fig. 6, the Y-axis direction center of the laser beam 21 moves from the +Y direction to the -Y direction as it advances in the -Z direction, so if the focusing point 23 is offset in the Z direction from the processing point, the Y-axis direction center of the processing mark will shift. Therefore, in the processing state by the laser beam 21 in the adjustment state shown in Fig. 6, a second processing line 121 is formed at a position shifted in the +Y direction from the center between a pair of first processing lines 120, as shown in Fig. 7.

[0036] Next, the function of the control unit 90 of the laser processing device 1 shown in Fig. 1 will be described in detail. Fig. 8 is a diagram showing a first image 71 obtained by imaging the first groove 130. Fig. 9 is a diagram showing a second image 72 obtained by imaging the second groove 140. Fig. 10 is a diagram showing a third image 73 obtained by imaging the third groove 150. Fig. 11 is a diagram showing an example of the relationship between the height position of the focal point 23 and the horizontal deviation amounts 132, 142. Figs. 8, 9, and 10 are images obtained by imaging a predetermined imaging area of ​​the upper surface 101 of the workpiece 100 by the imaging unit 70.

[0037] 8 is formed in the workpiece 100 by converging the laser beam 21 at a position of a first height 26 (see FIG. 11) based on the top surface 101 of the workpiece 100. A center line 131 of the first groove 130 is shifted in the -Y direction by a shift amount 132 with respect to a reference line 74. The reference line 74 is a line parallel to the X-axis direction that is set in advance in the imaging area imaged by the imaging unit 70.

[0038] 9 is formed in the workpiece 100 by focusing the laser beam 21 at a position of a second height 27 (see FIG. 11) that is based on the upper surface 101 of the workpiece 100 and is different from the first height 26. The center line 141 of the second groove 140 is shifted by a shift amount 142 in the +Y direction with respect to the reference line 74.

[0039] 10, a third groove 150 is formed in the workpiece 100 by focusing the laser beam 21 on the top surface 101 of the workpiece 100. A center line 151 of the third groove 150 coincides with the reference line 74.

[0040] 1 stores a correlation 94 (see FIG. 11) between the height position (first height 26 and second height 27) of the focusing point 23 of the laser beam 21 and the deviation amounts 132, 142. The correlation 94 between the height position of the focusing point 23 of the laser beam 21 and the deviation amounts 132, 142 is based on the deviation amounts 132, 142 between the center line 131 of the first groove 130 in the first image 71 and the center line 141 of the second groove 140 in the second image 72, as shown in FIG.

[0041] 11 is a proportional relationship in which the deviation is 0 μm when the height position of the focal point 23 is the top surface 101 of the workpiece 100, that is, the correlation 94 passes through the origin. In the embodiment, the first height 26 is set to a position below (−Z direction) the top surface 101 of the workpiece 100, and the second height 27 is set to a position above (+Z direction) the top surface 101 of the workpiece 100, but either one may be set to the top surface 101 of the workpiece 100. Since the correlation 94 is a proportional relationship, it can be calculated based on the deviation amounts at at least two height positions.

[0042] The calculation unit 92 predicts and calculates the amount of deviation (e.g., deviation amount 162 shown in FIG. 11) of a processed groove formed when the light-focusing point 23 is positioned at a predetermined height position (e.g., height position 28 shown in FIG. 11) based on the correlation 94 stored in the storage unit 91. For example, when the height position (defocus amount) of the light-focusing point 23 during processing is input to the processing conditions of the laser processing device 1, the calculation unit 92 automatically calculates the amount of deviation corresponding to the defocus amount.

[0043] When processing is performed with the light-focus point 23 positioned at a predetermined height position (for example, height position 28 shown in FIG. 11), the correction unit 93 automatically corrects the horizontal position of the light-focus point 23 so as to cancel the amount of deviation (for example, deviation amount 162 shown in FIG. 11) calculated by the calculation unit 92. That is, the correction unit 93 corrects the light-focus point 23 to a coordinate position in which the positive and negative of the amount of deviation calculated by the calculation unit 92 are inverted in the Y-axis direction (indexing feed direction).

[0044] The function of the storage unit 91 is realized by the storage device of the control unit 90. The functions of the calculation unit 92 and the correction unit 93 are realized by the arithmetic processing unit of the control unit 90 executing a program stored in the storage device.

[0045] As described above, the laser processing device 1 according to the embodiment measures the correlation 94 between the height position (first height 26 and second height 27) of the focal point 23 and the deviation amounts 132, 142 of the processed groove in advance and stores it in the memory unit 91, and when processing is performed with the focal point 23 positioned at a predetermined height position 28, the calculation unit 92 automatically calculates the deviation amount 162. Furthermore, in the laser processing device 1 according to the embodiment, based on the deviation amount 162 calculated by the calculation unit 92, the correction unit 93 automatically corrects the horizontal position of the focal point 23 so as to offset the deviation amount 162. This reduces the adjustment work and shortens downtime, and also makes it possible to suppress deterioration of processing quality caused by differences in the focal point position.

[0046] It should be noted that the present invention is not limited to the above-described embodiment, and can be practiced in various modified forms without departing from the gist of the present invention. [Explanation of symbols]

[0047] 1 Laser processing equipment 10 Chuck table 11 Holding surface 20 Laser beam irradiation unit 21 Laser Beam 22 Condenser lens 23 Focus point 24, 25 Optical axis 26 1st Height 27 2nd Height 28 Height position 40 Processing feed unit 50 Indexing feed unit 60 Focus point position adjustment unit 70 Imaging unit 71 1st image 72 2nd image 73 3rd image 74 Reference Line 80 display units 90 Control Unit 91 Storage section 92 Calculation section 93 Correction section 94 Correlation 100 Workpiece 101 Top surface 120 First Processing Line 121 Second Processing Line 130 First groove 140 Second groove 150 Third groove 131, 141, 151 center line 132, 142, 162 Displacement

Claims

[Claim 1] A chuck table for holding the workpiece; a laser beam irradiation unit including a condenser lens for condensing and irradiating a laser beam onto the workpiece held on the chuck table; a processing feed unit that relatively moves the chuck table and the focal point of the laser beam in a processing feed direction; an indexing feed unit that relatively moves the chuck table and the focal point of the laser beam in an indexing feed direction perpendicular to the processing feed direction; a focus position adjustment unit that adjusts the height position of the focus by moving the focus lens in a direction perpendicular to the holding surface of the chuck table; An imaging unit for imaging the workpiece; a display unit that displays an image captured by the imaging unit; A control unit, The control unit a memory unit that stores a correlation between a height position of a focusing point of the laser beam and an amount of deviation in the indexing feed direction between a center line of a first groove in a first image obtained by imaging a first groove along the processing feed direction formed in the workpiece by focusing the laser beam at a position of a first height based on the top surface of the workpiece, and a center line of a second groove in a second image obtained by imaging a second groove along the processing feed direction formed in the workpiece by focusing the laser beam at a position of a second height based on the top surface of the workpiece and different from the first height, and A calculation unit that predicts and calculates a deviation amount in the indexing feed direction of a processed groove that is formed when a light condensing point is positioned at a predetermined height position based on the correlation stored in the storage unit; and a correction unit that automatically corrects the horizontal position of the light-focusing point to a coordinate position obtained by inverting the positive and negative of the deviation calculated by the calculation unit in the indexing feed direction when processing is performed with the light-focusing point positioned at the predetermined height position; A laser processing device comprising:

Images