Laser processing apparatus, program, non-temporary recording medium, and method for processing a workpiece.

Abstract

To provide a laser processing device which can remove chips adhering to a groove while forming the groove in a workpiece, and flexibly change a position of a laser beam with which the workpiece is irradiated.SOLUTION: A laser processing device for processing a workpiece comprises: a holding unit; a laser beam irradiation unit; a processing feeding mechanism; and a control unit. The control unit executes the procedure of moving a focusing point in the first movement direction intersecting the processing feeding direction within a range of the width of a processing scheduled line when the focusing point and a holding unit relatively move along the processing feeding direction according to a program, and the procedure of controlling the power of the laser beam such that the power of the laser beam in a case where the focusing point is located in a region on an outer edge side of the processing scheduled line becomes smaller in comparison to a case where the focusing point is located in a region on the center side of the processing scheduled line when the focusing point moves in the first movement direction to form a groove on the processing scheduled line.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laser processing apparatus used when processing a plate-shaped workpiece such as a wafer, a program used for controlling the laser processing apparatus, a non-temporary recording medium storing the program, and a method for processing a workpiece.

Background Art

[0002] In electronic devices typified by mobile phones and personal computers, a device chip having devices such as electronic circuits is an essential component. The device chip is obtained, for example, by partitioning the surface side of a wafer made of a semiconductor such as silicon into a plurality of regions by streets (processing planned lines), forming devices in each region, and then dividing the wafer along these streets.

[0003] When dividing a plate-shaped workpiece such as a wafer into small pieces such as device chips, for example, a cutting device in which an annular grinding tool called a cutting blade is attached to a spindle serving as a rotation axis is used. By cutting the workpiece along the street with the cutting blade rotated at high speed, the workpiece is cut along this street and divided into a plurality of small pieces.

[0004] In recent years, a low dielectric constant material (Low-k material) having a lower dielectric constant than conventional materials has been adopted for an interlayer insulating film or the like constituting a device so as to reduce the capacitance between wirings that causes signal delay. On the other hand, this low dielectric constant material is more brittle than conventional materials and may be damaged and peeled off when processed by the above-described mechanical method. Therefore, when a workpiece having a film of a low dielectric constant material is mechanically processed, a portion overlapping the street of the film is removed in advance by a laser beam.

[0005] Specifically, this process, called laser ablation, involves absorbing a laser beam into the workpiece to remove portions that overlap the film's streets. However, this method partially melts and vaporizes the workpiece with the laser beam, making it prone to generating debris and recast material. For example, if debris adheres to the edges or walls of the grooves formed in the streets during film removal, the quality of the device chip deteriorates.

[0006] To solve this problem, a method has been proposed in which a weak laser beam is irradiated again onto the edges of grooves where debris has adhered to remove the debris (see, for example, Patent Documents 1 and 2). By irradiating the area where debris has adhered with a weak laser beam, the debris is melted and evaporated by the weak laser beam and removed from the workpiece. In this method, since a weak laser beam is used, the shape of the groove does not change significantly. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2009-49390 [Patent Document 2] Japanese Patent Publication No. 2010-284670 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, in the method described above, where a laser beam is irradiated onto the workpiece to form grooves, and then a weaker laser beam is irradiated again, even a slight shift in the position of the weaker laser beam irradiated onto the workpiece can result in improper removal of debris. It is also conceivable to use a diffraction grating to split the laser beam and perform groove formation and debris removal simultaneously, but this method requires expensive diffraction gratings with fixed branching patterns, making it difficult to change the position of the laser beam irradiated onto the workpiece when the groove width is changed, etc.

[0009] Therefore, the object of the present invention is to provide a laser processing apparatus that can form grooves in a workpiece while removing debris adhering to these grooves, and that can flexibly change the position of the laser beam irradiated onto the workpiece. [Means for solving the problem]

[0010] According to one aspect of the present invention, a laser processing apparatus for processing a workpiece by irradiating a laser beam onto a processing line having a predetermined width set on the workpiece, comprising: a holding unit for holding the workpiece; a laser beam irradiation unit for irradiating the workpiece held by the holding unit in such a way that the laser beam is focused onto the workpiece; a processing feed mechanism for moving the focusing point where the laser beam is focused and the holding unit relative to each other along the processing feed direction; and a control unit having a processing device and a storage device, which controls the laser beam irradiation unit and the processing feed mechanism according to a program stored in the storage device, wherein the laser beam irradiation unit comprises: a laser oscillator for generating the laser beam; a concentrator for focusing the laser beam generated by the laser oscillator onto the focusing point; and a first focusing point moving unit positioned between the laser oscillator and the concentrator for moving the focusing point in a first moving direction intersecting the processing feed direction on the workpiece. A second focusing point moving unit is positioned between the laser oscillator and the focusing unit and moves the focusing point in a second movement direction intersecting the first movement direction on the workpiece, The control unit includes a procedure for moving the focusing point and the holding unit relative to the machining feed direction, such that the direction of the width of the machining line is perpendicular to the machining feed direction, and a procedure for moving the focusing point in the first movement direction within the width of the machining line as the focusing point and the holding unit move relative to each other along the machining feed direction. A procedure for moving the focusing point in the second movement direction when the focusing point and the holding unit move relative to each other along the processing feed direction, A procedure for controlling the power of a laser beam such that, as the focusing point moves in the first direction of movement, the power of the laser beam is reduced when the focusing point is located in the region on the outer edge of the processing line compared to when it is located in the region on the central side of the processing line; A procedure for controlling the range of movement of the focusing point in the first movement direction such that, when the focusing point moves in the second movement direction, the range of movement of the focusing point in the first movement direction is wider on the rear side than on the front side in the direction in which the focusing point and the holding unit move relative to each other; A laser processing apparatus is provided that performs the following operation to form grooves in the planned processing line.

[0013] According to another aspect of the present invention, the present invention comprises a holding unit for holding a workpiece on which a processing line of a predetermined width is set, a laser beam irradiation unit for irradiating the workpiece held by the holding unit in such a way that a laser beam is focused onto it, a processing feed mechanism for moving the focal point where the laser beam is focused and the holding unit relative to each other along the processing feed direction, and a control unit having a processing device and a storage device for controlling the laser beam irradiation unit and the processing feed mechanism according to a program, wherein the laser beam irradiation unit comprises a laser oscillator for generating the laser beam, a concentrator for focusing the laser beam generated by the laser oscillator onto the focal point, and a first focal point moving unit positioned between the laser oscillator and the concentrator for moving the focal point in a first moving direction intersecting the processing feed direction on the workpiece, A second focusing point moving unit is positioned between the laser oscillator and the focusing unit and moves the focusing point in a second movement direction intersecting the first movement direction on the workpiece, A program used when forming a groove in a laser processing apparatus having the following, the program comprising: a step of moving the focusing point and the holding unit relative to the processing feed direction such that the direction of the width of the processing line is perpendicular to the processing feed direction; and a step of moving the focusing point in the first movement direction within the width range of the processing line as the focusing point and the holding unit move relative to each other along the processing feed direction, A procedure for moving the focusing point in the second movement direction when the focusing point and the holding unit move relative to each other along the processing feed direction, A procedure for controlling the power of a laser beam such that, as the focusing point moves in the first direction of movement, the power of the laser beam is reduced when the focusing point is located in the region on the outer edge of the processing line compared to when it is located in the region on the central side of the processing line; A procedure for controlling the range of movement of the focusing point in the first movement direction such that, when the focusing point moves in the second movement direction, the range of movement of the focusing point in the first movement direction is wider on the rear side than on the front side in the direction in which the focusing point and the holding unit move relative to each other; A program is provided that causes the control unit to execute the following.

[0016] According to yet another aspect of the present invention, a non-temporary recording medium on which the above-mentioned program is recorded is provided.

[0017] According to yet another aspect of the present invention, a method for processing a workpiece used to form a groove in a processing line, comprising: a holding unit for holding a workpiece on which a processing line of predetermined width is set; a laser beam irradiation unit for irradiating the workpiece held by the holding unit in such a way that a laser beam is focused onto the workpiece; and a processing feed mechanism for moving the focusing point where the laser beam is focused and the holding unit relative to each other along the processing feed direction, the method comprising: moving the focusing point and the holding unit relative to each other along the processing feed direction, with the direction of the width of the processing line being perpendicular to the processing feed direction; and moving the focusing point in a first movement direction that intersects the processing feed direction within the width of the processing line as the focusing point and the holding unit move relative to each other along the processing feed direction, As the focusing point and the holding unit move relative to each other along the processing feed direction, the step of moving the focusing point in a second movement direction intersecting the first movement direction, A step of controlling the power of the laser beam such that, as the focusing point moves in the first direction of movement, the power of the laser beam is reduced when the focusing point is located in the region on the outer edge of the processing line compared to when it is located in the region on the central side of the processing line. A step of controlling the range of movement of the focusing point in the first movement direction such that, when the focusing point moves in the second movement direction, the range of movement of the focusing point in the first movement direction is wider on the rear side than on the front side in the direction in which the focusing point and the holding unit move relative to each other. A method for processing a workpiece including the above is provided.

[0018] Preferably, the process further includes moving the focusing point in a second movement direction intersecting the first movement direction as the focusing point and the holding unit move relative to each other along the processing feed direction.

[0019] Preferably, the method further includes the step of controlling the range of movement of the focusing point in the first movement direction such that, as the focusing point moves in the second movement direction, the range of movement of the focusing point in the first movement direction is wider on the rearward side than on the forward side in the direction in which the focusing point and the holding unit move relative to each other. [Effects of the Invention]

[0020] In the laser processing apparatus, program, and method for processing a workpiece according to each aspect of the present invention, when the condensing point of the laser beam and the holding unit relatively move along the processing feed direction, the condensing point moves in a first moving direction that intersects the processing feed direction within the width range of the planned processing line, and the power of the laser beam is controlled so that it becomes smaller when the condensing point is located in the region on the outer edge side of the planned processing line than when it is located in the region on the center side of the planned processing line. Therefore, a groove is formed in the workpiece with a high-power laser beam irradiated to the region on the center side of the planned processing line, and in parallel with the formation of this groove, chips adhering to the groove are removed with a low-power laser beam irradiated to the region on the outer edge side of the planned processing line.

[0021] Further, in the laser processing apparatus, program, and method for processing a workpiece according to each aspect of the present invention, the laser beam is not branched by a diffraction grating or the like, and the condensing point is moved in a first moving direction that intersects the processing feed direction by a first condensing point moving unit, so that groove formation and chip removal are performed in parallel. That is, since the position of the laser beam irradiated to the workpiece moves in the first moving direction by the first condensing point moving unit, it is possible to flexibly change the position of the laser beam irradiated to the workpiece compared to the case where the laser beam is branched by a diffraction grating.

[0022] Thus, according to the present invention, there is provided a laser processing apparatus or the like that can remove chips adhering to a groove while forming a groove in a workpiece and can flexibly change the position of the laser beam irradiated to the workpiece.

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is a perspective view showing a laser processing apparatus. [Figure 2] FIG. 2 is a diagram showing the structure of a laser beam irradiation unit. [Figure 3] FIG. 3 is a functional block diagram schematically showing the functional structure of a control unit. [Figure 4]FIG. 4 is a top view showing the state where the condensing point moves within the range of the width of the street. [Figure 5] FIG. 5 is a flowchart showing a method of processing a workpiece. [Figure 6] FIG. 6 is a diagram showing the structure of a laser beam irradiation unit according to a modified example. [Figure 7] FIG. 7 is a top view showing the state where the condensing point moves within the range of the width of the street in the modified example.

Embodiments for Carrying Out the Invention

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a laser processing apparatus 2 of the present embodiment. In FIG. 1, some components of the laser processing apparatus 2 are represented by functional blocks. Also, the X-axis direction (processing feed direction), Y-axis direction (indexing feed direction), and Z-axis direction (vertical direction) used in the following description are perpendicular to each other.

[0025] As shown in FIG. 1, the laser processing apparatus 2 includes a base 4 on which each component is mounted. On the upper surface of the base 4, a horizontal movement mechanism (processing feed mechanism, indexing feed mechanism) 6 is arranged. The horizontal movement mechanism 6 includes a pair of Y-axis guide rails 8 fixed to the upper surface of the base 4 and generally parallel to the Y-axis direction. A Y-axis movement plate 10 is attached to the Y-axis guide rails 8 in a manner that can slide along the Y-axis direction.

[0026] On the lower surface side of the Y-axis movement plate 10, a nut portion (not shown) constituting a ball screw is provided. A screw shaft 12 generally parallel to the Y-axis guide rails 8 is connected to this nut portion in a rotatable manner. A Y-axis pulse motor 14 is connected to one end of the screw shaft 12. By rotating the screw shaft 12 with the Y-axis pulse motor 14, the Y-axis movement plate 10 moves along the Y-axis guide rails 8 (Y-axis direction).

[0027] A pair of X-axis guide rails 16, which are generally parallel to the X-axis direction, are provided on the upper surface of the Y-axis moving plate 10. The X-axis moving plate 18 is mounted on the X-axis guide rails 16 in such a manner that it can slide along the X-axis direction. A nut portion (not shown) that constitutes a ball screw is provided on the lower surface of the X-axis moving plate 18.

[0028] A screw shaft 20, which is roughly parallel to the X-axis guide rail 16, is connected to this nut portion in a manner that allows it to rotate. An X-axis pulse motor 22 is connected to one end of the screw shaft 20. By rotating the screw shaft 20 with the X-axis pulse motor 22, the X-axis moving plate 18 moves along the X-axis guide rail 16 (in the X-axis direction).

[0029] A cylindrical table base 24 is positioned on the upper side of the X-axis moving plate 18. A chuck table (holding unit) 26, used for holding the workpiece 11, is positioned on top of the table base 24. A rotational drive source (not shown), such as a motor, is connected to the lower part of the table base 24.

[0030] The force generated by the rotational drive source of the horizontal movement mechanism 6 causes the chuck table 26 to rotate around a rotation axis that is roughly parallel to the Z-axis direction. In addition, the table base 24 and the chuck table 26 move along the X-axis direction (machining feed) due to the force generated by the X-axis pulse motor 22 of the horizontal movement mechanism 6, and move along the Y-axis direction (indexing feed) due to the force generated by the Y-axis pulse motor 14 of the horizontal movement mechanism 6.

[0031] The workpiece 11 is, for example, a disc-shaped wafer made of a semiconductor such as silicon. That is, the workpiece 11 has a circular surface and a circular back surface opposite to the surface. The surface side of the workpiece 11 is divided into multiple small regions by multiple streets (processing lines) of a predetermined width that intersect each other, and devices such as integrated circuits (ICs) are formed in each small region. The laser processing apparatus 2 of this embodiment is used, for example, when forming grooves in the streets of the workpiece 11.

[0032] In this embodiment, a circular tape 13 is attached to the back (or front) surface of the workpiece 11, and an annular frame 15 surrounding the workpiece 11 is fixed to the outer edge of the tape 13. That is, the workpiece 11 is supported by the annular frame 15 via the tape 13. This improves the ease of handling the workpiece 11. However, the workpiece 11 may be processed without the tape 13 attached or without being supported by the annular frame 15.

[0033] In this embodiment, a disc-shaped wafer made of a semiconductor such as silicon is used as the workpiece 11, but the material, shape, structure, size, etc. of the workpiece 11 are not limited to this embodiment. For example, substrates made of other semiconductors, ceramics, resins, metals, etc. may be used as the workpiece 11. Similarly, the type, quantity, shape, structure, size, arrangement, etc. of devices are not limited to the above embodiment. Devices do not need to be formed on the workpiece 11.

[0034] A portion of the upper surface of the chuck table 26 is a holding surface 26a that contacts the tape 13 (or the workpiece 11 if the tape 13 is not attached to the workpiece 11) to hold the workpiece 11, and is typically made of porous ceramics. This holding surface 26a is generally parallel to the X-axis and Y-axis directions.

[0035] Furthermore, the holding surface 26a is connected to a suction source (not shown), such as a vacuum pump, via a flow path (not shown) provided inside the chuck table 26. Four clamps 28 are provided around the chuck table 26, which can fix an annular frame 15 that supports the workpiece 11.

[0036] A support structure 30 is provided on one side of the horizontal movement mechanism 6 in the Y-axis direction, with a side surface that is generally parallel to the Z-axis direction. A vertical movement mechanism (height adjustment mechanism) 32 is positioned on the side surface of this support structure 30. The vertical movement mechanism 32 is fixed to the side surface of the support structure 30 and includes a pair of Z-axis guide rails 34 that are generally parallel to the Z-axis direction. A Z-axis movement plate 36 is attached to the Z-axis guide rails 34 in such a manner that it can slide along the Z-axis direction.

[0037] A nut portion (not shown) that constitutes a ball screw is provided on the back side (Z-axis guide rail 34 side) of the Z-axis moving plate 36. A screw shaft (not shown) that is roughly parallel to the Z-axis guide rail 34 is connected to this nut portion in a manner that allows it to rotate. A Z-axis pulse motor 38 is connected to one end of the screw shaft. By rotating the screw shaft with the Z-axis pulse motor 38, the Z-axis moving plate 36 moves along the Z-axis guide rail 34 (in the Z-axis direction).

[0038] A support 40 is fixed to the surface side of the Z-axis moving plate 36, and this support 40 supports a part of a laser beam irradiation unit 42 that can irradiate a workpiece 11 held by the chuck table 26 in a way that focuses the laser beam. Figure 2 is a diagram showing the structure of the laser beam irradiation unit 42. Note that in Figure 2 as well, some components are represented as functional blocks. As shown in Figure 2, the laser beam irradiation unit 42 includes, for example, a laser oscillator 44 fixed to the base 4.

[0039] The laser oscillator 44 typically uses a laser medium such as Nd:YAG suitable for laser oscillation and generates a pulsed laser beam A with a wavelength absorbed by the workpiece 11. Downstream of the laser oscillator 44 along the direction of propagation of the laser beam A, for example, an acoustic optical deflector (AOD) (first focusing point shifting unit) 48 is arranged, and the laser beam A emitted from the laser oscillator 44 is incident on this acoustic optical deflector 48.

[0040] The acousto-optic deflection element 48 generates acoustic waves (ultrasound) corresponding to the power value and frequency of the supplied high-frequency power (RF power), and uses the interaction with these acoustic waves to quickly adjust the power and direction of laser beam A. Specifically, the power of laser beam A is adjusted based on the power value, and the direction of laser beam A is adjusted based on the frequency. However, the power of laser beam A may be adjusted inside the laser oscillator 44, or it may be adjusted by an adjuster such as an attenuator.

[0041] The laser beam A, whose power and direction of travel have been adjusted by the acousto-optic deflection element 48, is incident on a cylindrical housing 50 (Figure 1) supported by a support 40, for example. An irradiation head 52 (Figure 1) is provided at the end of the housing 50 on the side of the horizontal movement mechanism 6 (the other side in the Y-axis direction). A mirror 54 is positioned on the upper part of the irradiation head 52, and this mirror 54 changes the direction of travel of the laser beam A downward.

[0042] A light-gathering device 56 is positioned at the bottom of the irradiation head 52, for example, to focus the laser beam A onto a lower focusing point B. The laser beam A is then irradiated onto the workpiece 11 held by the chuck table 26 through this light-gathering device 56. The light-gathering device 56 includes an fθ lens 58, which focuses the laser beam A onto a focusing point B at a predetermined height from the holding surface 26a of the chuck table 26, regardless of its direction of travel.

[0043] The focal point B of the laser beam A is moved by the acousto-optic deflection element 48 described above, for example, in a first movement direction D1 that intersects with the X-axis direction on the workpiece 11. The first movement direction D1 is typically parallel to the Y-axis direction (perpendicular to the X-axis direction), but it may also be inclined with respect to the Y-axis direction. The focal point B may be located inside the workpiece 11 or outside (above) the workpiece 11. The diameter of the laser beam A on the upper surface of the workpiece 11 is, for example, about 3 μm to 1000 μm.

[0044] As shown in Figure 1, a camera (imaging unit) 60 fixed to the housing 50 is positioned in one region of the irradiation head 52 in the X-axis direction. The camera 60 includes, for example, a two-dimensional optical sensor such as a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor that is sensitive to visible light, and is used to image the workpiece 11 held by the chuck table 26.

[0045] The housing 50 and irradiation head 52 of the laser beam irradiation unit 42 move along the Z-axis direction by the force generated by the Z-axis pulse motor 38 of the vertical movement mechanism 32, together with the camera 60 described above. In other words, the vertical movement mechanism 32 moves components such as the mirror 54 and the light concentrator 56 provided on the irradiation head 52 in a direction that is roughly perpendicular to the holding surface 26a of the chuck table 26.

[0046] In this embodiment, the case in which the laser oscillator 44 and the like are fixed to the base 4 has been described as an example. However, the laser oscillator 44 and the like may be supported by the vertical movement mechanism 32 together with the housing 50 and the like, and configured to move along the Z-axis direction. Furthermore, the irradiation head 52 may be provided with an actuator or the like so that only the light concentrator 56 inside the irradiation head 52 can be moved independently along the Z-axis direction.

[0047] A control unit 62 is connected to components such as the horizontal movement mechanism 6, the vertical movement mechanism 32, the laser beam irradiation unit 42, and the camera 60. The control unit 62 is composed of a computer, for example, a processing unit 64 and a storage device 66, and controls the operation of each of the above-mentioned components so that the workpiece 11 is processed appropriately.

[0048] The processing unit 64 is typically a CPU (Central Processing Unit) and performs various processes necessary to control the components described above. The storage device 66 includes, for example, a main memory such as DRAM (Dynamic Random Access Memory) and an auxiliary storage device such as a hard disk drive or flash memory. The functions of this control unit 62 are realized, for example, by the operation of the processing unit 64 according to software such as a program stored in the storage device 66.

[0049] The upper part of the base 4 is covered by a cover (not shown) that can accommodate each component. A touchscreen (input device, output device) 68, which serves as a user interface, is located on the side of this cover. The control unit 62 is also connected to the touchscreen 68, and various conditions applied when processing the workpiece 11, for example, are input from the operator to the control unit 62 via the touchscreen 68.

[0050] Furthermore, a keyboard or mouse may be used as the input device. Similarly, a display device such as a liquid crystal display that does not have an input function, a speaker that can transmit information by sound, or an indicator light that can transmit information by the color or state of light emission (illumination, blinking, off, etc.) may be used as the output device.

[0051] In the laser processing apparatus 2 configured in this way, the laser beam A is irradiated onto the workpiece 11 in a predetermined manner defined by the program. For example, a program is recorded in a part of the storage device 66, which is also a non-temporary recording medium that can be read by a computer or the like, that causes the processing device 64 to execute a series of processes necessary for irradiating the workpiece A. The control unit 62 (processing device 64) performs the procedures necessary for irradiating the workpiece 11 with the laser beam A according to this program.

[0052] Figure 3 is a functional block diagram schematically showing the functional structure of the control unit 62 realized by the program of this embodiment. For the sake of explanation, Figure 3 also shows the horizontal movement mechanism 6 (including a rotational drive source for rotating the chuck table 26), the laser beam irradiation unit 42, the touchscreen 68, etc., which are connected to the control unit 62.

[0053] As shown in Figure 3, the control unit 62 includes a rotation control unit 62a that controls the rotation of the chuck table 26 around a rotation axis that is approximately parallel to the Z-axis direction. When the rotation control unit 62a receives a command, for example, to machine a workpiece 11 held on the chuck table 26 along a desired street, it rotates the chuck table 26 with the rotation drive source of the horizontal movement mechanism 6 so that the direction of the width of the street in question is perpendicular to the X-axis direction.

[0054] In other words, the rotational drive source rotates the chuck table 26 so that the length direction perpendicular to the width direction of the target street is parallel to the X-axis direction. Typically, the command to machine the workpiece 11 along the street is input from the operator to the control unit 62 via the touchscreen 68. However, this command may also be generated internally by the control unit 62 based on a program or the like.

[0055] Furthermore, the control unit 62 includes an X-axis movement control unit (machining feed control unit) 62b that controls the movement of the chuck table 26 along the X-axis direction (machining feed), and a Y-axis movement control unit (indexing feed control unit) 62c that controls the movement of the chuck table 26 along the Y-axis direction (indexing feed).

[0056] When the X-axis movement control unit 62b and the Y-axis movement control unit 62c receive a command, for example, to machine a workpiece 11 held in the chuck table 26 along a desired street, they adjust the position of the chuck table 26 along the X-axis and the position of the chuck table 26 along the Y-axis using the horizontal movement mechanism (machining feed mechanism, indexing feed mechanism) 6.

[0057] Specifically, the horizontal movement mechanism (machining feed mechanism) 6 adjusts the position of the chuck table 26 along the X-axis direction, and the horizontal movement mechanism (indexing feed mechanism) 6 adjusts the position of the chuck table 26 along the Y-axis direction, so that the irradiation head 52 is positioned above the extension of the street along the direction of the length of the target street. Here, the procedure for adjusting the position along the X-axis direction and the position along the Y-axis direction may be performed before the rotation procedure described above, simultaneously with (in parallel with) the rotation procedure, or after the rotation procedure.

[0058] After the rotation procedure described above, and the adjustment procedure between the position along the X-axis and the position along the Y-axis are completed, the X-axis movement control unit 62b moves the chuck table 26 along the X-axis using the horizontal movement mechanism (machining feed mechanism) 6. That is, the horizontal movement mechanism (machining feed mechanism) 6 moves the chuck table 26 and the irradiation head 52 relative to each other along the X-axis so that the area directly below the irradiation head 52 passes over the workpiece 11.

[0059] As a result, the focusing point B of the laser beam A, located directly below the irradiation head 52, moves along the X-axis relative to the chuck table 26 and passes through the street of the workpiece 11 along its length. In this way, the X-axis movement control unit 62b moves the focusing point B of the laser beam A and the chuck table 26 relative to each other along the X-axis, with the direction of the street width perpendicular to the X-axis.

[0060] Furthermore, the control unit 62 includes a laser oscillation control unit 62d that controls the generation of the laser beam A by the laser oscillator 44. The laser oscillation control unit 62d generates the laser beam A using the laser oscillator 44 while the focal point B of the laser beam A and the chuck table 26 are moving relative to each other along the X-axis, and irradiates the workpiece 11 with the laser beam A from the irradiation head 52. As a result, the laser beam A is irradiated onto the target street of the workpiece 11.

[0061] The control unit 62 further includes a focal point movement control unit 62e that moves the focal point B of the laser beam A, and a laser power control unit 62f that controls the power of the laser beam A. For example, during the procedure described above in which the focal point B and the chuck table 26 are moved relative to each other along the X-axis, the focal point movement control unit 62e moves the focal point B in a first movement direction D1 that intersects the X-axis direction within the width of the street using the acousto-optic deflection element 48.

[0062] Figure 4 is a top view showing how the focusing point B moves within the width range of the street (planned machining line) 17 of the workpiece 11. In this embodiment, the focusing point movement control unit 62e moves the focusing point B in a first movement direction D1 so as to move from the central area toward the outer edge area in the direction of the width of the street 17.

[0063] Specifically, for example, the focusing point movement control unit 62e moves the focusing point B from the central position B11 shown in Figure 4 toward the outer edge, in the order of positions B12, B13, B14, B15, B16, and B17, according to a preset timing. The focusing point B that has moved to position B17 returns to position B11 at the timing of the next movement. The focusing point movement control unit 62e may also move the focusing point B in accordance with the timing of the generation of the pulsed laser beam A, etc.

[0064] The spacing between adjacent focal points B can be arbitrarily set in a manner that achieves the desired overlap of the laser beam A's irradiated areas, depending on the repetition frequency of the laser beam A's oscillation, the width of the street 17, the required processing quality, etc., for example, from 0.01 μm to 500 μm, typically 2 μm. Similarly, the number of focal points B can also be arbitrarily set.

[0065] As described above, the focusing point B and the chuck table 26 move relative to each other along the X-axis direction by the horizontal movement mechanism 6. Therefore, while the focusing point B moves from position B11 to position B17 along the first movement direction D1, the focusing point B and the workpiece 11 move slightly relative to each other along the X-axis direction.

[0066] In Figure 4, the focusing point B moves in the opposite direction to the X-axis direction relative to the workpiece 11 (i.e., to the left in Figure 4) by the horizontal movement mechanism 6, and the chuck table 26 move relative to the focusing point B along the X-axis direction. The speed and timing of the movement of the focusing point B in the first movement direction D1 and the relative movement speed along the X-axis direction are set within a range that allows the street 17 of the workpiece 11 to be properly processed by the laser beam A.

[0067] The laser power control unit 62f adjusts the power of the laser beam A using the acousto-optic deflection element 48 so that when the focusing point movement control unit 62e moves the focusing point B in the first movement direction D1, the power of the laser beam A is lower when the focusing point B is located in the outer edge region of the street 17 compared to when the focusing point B is located in the central region of the street 17.

[0068] Specifically, in this embodiment, the acousto-optic deflection element 48 adjusts the power of the laser beam A such that the power of the laser beam A is lower when the focal point B is located at positions B16 and B17 compared to when the focal point B is located at positions B11, B12, B13, B14, and B15. For example, the power of the laser beam A when the focal point B is located at positions B16 and B17 is adjusted to about 1% to 80% of the power of the laser beam A when the focal point B is located at positions B11, B12, B13, B14, and B15.

[0069] As a result, a low-power laser beam A is irradiated onto the edge of the groove formed in street 17 with a high-power laser beam A, and debris such as recast materials attached to the edge of this groove is removed by the low-power laser beam A. In Figure 4, the positions B11, B12, B13, B14, B15, B16, and B17 of the focal point B are each indicated by circles of a size (diameter) corresponding to the power of laser beam A.

[0070] However, there are no particular restrictions on the manner in which the focal point B is moved and the manner in which the power of the laser beam A is adjusted. For example, the focal point movement control unit 62e may move the focal point B from one position B16 (or the other position B17) on the outer edge, through the central position B11, and then back to the other position B17 (or the other position B16) on the outer edge. In addition, the laser power control unit 62f may adjust the power of the laser beam A using the acousto-optic deflection element 48 so that the power of the laser beam A decreases sequentially from the central position B11 towards the outer edge positions B16 and B17.

[0071] Figure 5 is a flowchart showing the processing flow when the laser processing apparatus 2 irradiates the workpiece 11 with a laser beam A, that is, the processing method for the workpiece 11. First, when the control unit 62 receives a command to process the workpiece 11 along a desired street 17, the rotation control unit 62a, the X-axis movement control unit 62b, and the Y-axis movement control unit 62c perform a procedure to adjust the orientation and position of the target street 17 with respect to the irradiation head 52 (step ST11).

[0072] Specifically, the rotation control unit 62a rotates the chuck table 26 using the rotation drive source of the horizontal movement mechanism 6 so that the direction of the length of the target street 17 is parallel to the X-axis direction (i.e., the direction of the width is perpendicular to the X-axis direction). In addition, the X-axis movement control unit 62b and the Y-axis movement control unit 62c adjust the position of the chuck table 26 along the X-axis direction and the Y-axis direction using the horizontal movement mechanism (machining feed mechanism, indexing feed mechanism) 6 so that the irradiation head 52 is positioned above the extension line of the street 17 along the direction of the length of the target street 17.

[0073] After the orientation and position of the target street 17 with respect to the irradiation head 52 have been adjusted, the laser oscillation control unit 62d starts laser oscillation and the X-axis movement control unit 62b performs a procedure to move the focusing point B and the chuck table 26 relative to the X-axis direction, with the direction of the length of the target street 17 parallel to the X-axis direction (step ST12).

[0074] Specifically, the laser oscillation control unit 62d starts generating a pulsed laser beam A using the laser oscillator 44. The X-axis movement control unit 62b moves the chuck table 26 along the X-axis direction using the horizontal movement mechanism (processing feed mechanism) 6 so that the focal point B of the laser beam A, located directly below the irradiation head 52, passes through the street 17 of the workpiece 11 along its length.

[0075] After laser oscillation is started, with the focal point B and the chuck table 26 moving relative to each other along the X-axis, the focal point movement control unit 62e performs a procedure to move the focal point B in a first movement direction D1 that intersects the X-axis within the width of the street using the acousto-optic deflection element 48 (step ST13). Specifically, the focal point movement control unit 62e changes the position of the focal point B with the acousto-optic deflection element 48 according to a predetermined sequence.

[0076] Furthermore, in accordance with the movement of the focal point B in the first movement direction D1, the laser power control unit 62f performs a procedure to adjust the power of the laser beam A using the acousto-optic deflection element 48 so that the power of the laser beam A is lower when the focal point B is located in the outer edge region of the street 17 compared to when the focal point B is located in the central region of the street 17 (step ST14). Specifically, the laser power control unit 62f adjusts the power of the laser beam A using the acousto-optic deflection element 48 so that a predetermined power is achieved according to the position of the focal point B.

[0077] The procedure for moving the focusing point B in the first movement direction D1 and the procedure for adjusting the power of the laser beam A are repeated, for example, until grooves are formed over the entire street 17 and the processing of the workpiece 11 is completed (NO in step ST15). Of course, after grooves have been formed over the entire street 17, grooves may be formed on other streets 17 using the same procedure. Once the processing of the workpiece 11 is complete (YES in step ST15), the processing method for the workpiece 11 according to this embodiment is finished.

[0078] As described above, in the laser processing apparatus 2, program, and processing method for the workpiece 11 according to this embodiment, when the focusing point B of the laser beam A and the chuck table (holding unit) 26 move relative to each other along the X-axis direction (processing feed direction), the focusing point B moves in a first movement direction D1 that intersects the X-axis direction within the width of the street (processing line) 17, and the power of the laser beam A is controlled such that the power of the laser beam A is smaller when the focusing point B is located in the outer edge region of the street 17 compared to when it is located in the central region of the street 17. Therefore, a groove is formed in the workpiece 11 by the high-power laser beam A irradiated on the central region of the street 17, and in parallel with the formation of this groove, debris adhering to the groove is removed by the low-power laser beam A irradiated on the outer edge region of the street 17.

[0079] Furthermore, in the laser processing apparatus 2, program, and processing method for the workpiece 11 according to this embodiment, the laser beam A is not branched by a diffraction grating or the like, and the acousto-optic deflection element (first focusing point moving unit) 48 moves the focusing point B in a first movement direction D1 that intersects with the X-axis direction, thereby performing groove formation and debris removal in parallel. In other words, since the position of the laser beam A irradiated onto the workpiece 11 is moved in the first movement direction D1 by the acousto-optic deflection element 48, it is possible to flexibly change the position of the laser beam A irradiated onto the workpiece 11 compared to the case where the laser beam A is branched by a diffraction grating.

[0080] Thus, according to this embodiment, a laser processing apparatus 2, a program, and a method for processing a workpiece 11 are provided that can form grooves in the workpiece 11 while removing debris adhering to these grooves, and that can flexibly change the position of the laser beam A irradiated onto the workpiece 11.

[0081] It should be noted that the present invention is not limited to the embodiments described above and can be implemented with various modifications. For example, in the embodiments described above, a program that implements various procedures by the laser processing apparatus 2 is recorded in the storage device 66 in the control unit 62, but this program may be recorded on any non-temporary recording medium that can be read by a computer or the like. For example, this program may be recorded on an optical disc such as a CD (Compact Disc) that can be distributed at low cost.

[0082] Furthermore, although the above-described embodiment shows a laser beam irradiation unit 42 that can move the focal point B of the laser beam A in a first movement direction D1, the laser processing apparatus 2 may incorporate a laser beam irradiation unit of a different form. Figure 6 shows the structure of a modified laser beam irradiation unit 142. Note that in Figure 6, some components are represented as functional blocks.

[0083] Similar to the laser beam irradiation unit 42 according to the embodiment described above, the modified laser beam irradiation unit 142 includes a laser oscillator 144. The laser oscillator 144 typically comprises a laser medium such as Nd:YAG suitable for laser oscillation and generates a pulsed laser beam A with a wavelength absorbed by the workpiece 11.

[0084] Downstream of the laser oscillator 144, along the direction of propagation of the laser beam A, are mirrors 148 and 150, and an acoustic optical deflector (AOD) (first focusing point moving unit) 152. The laser beam A emitted from the laser oscillator 144 is incident on the acoustic optical deflector 152 via mirrors 148 and 150.

[0085] The acousto-optic deflection element 152 generates acoustic waves (ultrasound) corresponding to the power value and frequency of the supplied high-frequency power (RF power), and uses the interaction with these acoustic waves to quickly adjust the power and direction of laser beam A. Specifically, the power of laser beam A is adjusted based on the power value, and the direction of laser beam A is adjusted based on the frequency. However, the power of laser beam A may be adjusted inside the laser oscillator 44, or it may be adjusted by an adjuster such as an attenuator.

[0086] The laser beam A, whose power and direction of travel have been adjusted by the acousto-optic deflection element 152, is incident on a polygon mirror (second focusing point moving unit) 158, which has multiple reflective surfaces, via, for example, mirrors 154 and 156. The polygon mirror 158 is connected to a rotational drive source (not shown), such as a motor, and as the polygon mirror 158 rotates, the direction of travel of the laser beam A reflected by the reflective surfaces of the polygon mirror 158 is changed. The rotation speed of the polygon mirror 158 is, for example, about 5000 rpm to 30000 rpm.

[0087] The laser beam A reflected by the polygon mirror 158 is irradiated onto the workpiece 11 through the focuser 160. The focuser 160 includes an fθ lens and focuses the laser beam A to a focal point B at a predetermined height from the holding surface 26a of the chuck table 26, regardless of its direction of travel. Thus, the modified laser beam irradiation unit 142 includes a polygon mirror 158 positioned between the laser oscillator 144 and the focuser 160.

[0088] In this laser beam irradiation unit 142, the focal point B of the laser beam A is moved by the acousto-optic deflection element 152 in a first movement direction D1 that intersects with the X-axis direction on the workpiece 11, and then moved by the polygon mirror 158 in a second movement direction D2 that intersects with the first movement direction D1 on the workpiece 11.

[0089] The first movement direction D1 is typically parallel to the Y-axis direction (perpendicular to the X-axis direction), but it may also be inclined relative to the Y-axis direction. Similarly, the second movement direction D2 is typically parallel to the X-axis direction (perpendicular to the Y-axis direction), but it may also be inclined relative to the X-axis direction. Furthermore, the focusing point B may be located inside the workpiece 11 or outside (above) the workpiece 11. The diameter of the laser beam A on the upper surface of the workpiece 11 is, for example, about 3 μm to 1000 μm.

[0090] A portion of the laser beam irradiation unit 142, including the laser oscillator 144, is fixed to the base 4 of the laser processing apparatus 2, while another portion of the laser beam irradiation unit 142, including the light concentrator 160, is housed in a housing 50 or irradiation head 52 supported by a vertical movement mechanism 32. However, the laser oscillator 144, etc., may be supported by the vertical movement mechanism 32 together with the housing 50, etc., and configured to move in the Z-axis direction. Similarly, the irradiation head 52 may be provided with an actuator or the like to move the light concentrator 160, etc., in the Z-axis direction.

[0091] The functions of the control unit 62 implemented by the program are the same as in the embodiment described above. However, when the modified laser beam irradiation unit 142 is used, the focusing point movement control unit 62e moves the focusing point B in a first movement direction D1 that intersects with the X-axis direction within the width of the street 17, and also moves the focusing point B in a second movement direction D2 that intersects with the first movement direction D1.

[0092] In other words, when the focusing point movement control unit 62e moves the focusing point B relative to the chuck table 26 along the X-axis, it uses the acousto-optic deflection element 152 to move the focusing point B in a first movement direction D1 that intersects the X-axis within the width of the street 17. Also, when the focusing point movement control unit 62e moves the focusing point B relative to the chuck table 26 along the X-axis, it uses the polygon mirror 158 to move the focusing point B in a second movement direction D2 that intersects the first movement direction D1.

[0093] Figure 7 is a top view showing how the focal point B moves within the width of the street 17 in a modified example. In this modified example, the focal point movement control unit 62e moves the focal point B in a first movement direction D1 so as to move from the central area to the outer edge area in the direction of the width of the street 17, and also moves the focal point B in a second movement direction D2 within a predetermined range.

[0094] Specifically, for example, the focusing point movement control unit 62e moves the focusing point B from the central position B21 shown in Figure 4 toward the outer edge, in the order of positions B22, B23, B24, B25, B26, B27, B28, and B29, according to a preset timing. The focusing point B that has moved to position B29 returns to position B21 at the timing of the next movement. The focusing point movement control unit 62e may also move the focusing point B in accordance with the timing of the generation of the pulsed laser beam A, etc.

[0095] The spacing between adjacent focal points B can be arbitrarily set in a manner that achieves the desired overlap of the laser beam A's irradiated areas, depending on the repetition frequency of the laser beam A's oscillation, the width of the street 17, the required processing quality, etc., for example, from 0.01 μm to 500 μm, typically 10 μm. Similarly, the number of focal points B can also be arbitrarily set.

[0096] Furthermore, for example, the focusing point movement control unit 62e moves the focusing point B in a predetermined range in the second movement direction D2 such that it moves from the front to the rear in the direction in which the focusing point B and the chuck table 26 (i.e., the workpiece 11) move relative to each other. The range of movement in the second movement direction D2 can be arbitrarily set according to the performance of the polygon mirror 158 and the required machining quality, but for example, it is 0.1 mm to 299 mm, and typically 20 mm.

[0097] Thus, in this modified example, the X-axis movement control unit 62b moves the focusing point B and the chuck table 26 relative to each other in the X-axis direction by the horizontal movement mechanism (machining feed mechanism) 6, while the focusing point movement control unit 62e moves the focusing point B in the first movement direction D1 by the acousto-optic deflection element 152, and then moves the focusing point B further in the second movement direction D2 by the polygon mirror 158.

[0098] In this modified example, the focusing point B and the chuck table 26 move relative to each other in the X-axis direction, such that the focusing point B moves in the opposite direction to the X-axis direction relative to the workpiece 11 (i.e., to the left in Figure 7). The machining of the workpiece 11 proceeds from the front side (right side in Figure 7) to the rear side (left side in Figure 7) in the direction in which the focusing point B and the chuck table 26 move relative to each other.

[0099] The speed and timing of the movement of the focal point B in the first movement direction D1, the speed and timing of the movement of the focal point B in the second movement direction D2, and the relative movement speed along the X-axis direction are set within a range that allows the laser beam A to appropriately process the street 17 of the workpiece 11. In this embodiment, the movement of the focal point B in the first movement direction D1, realized by the acousto-optic deflection element 152, is faster and the range of movement is narrower compared to the movement of the focal point B in the second movement direction D2, realized by the polygon mirror 158.

[0100] In this modified configuration as well, the laser power control unit 62f adjusts the power of the laser beam A using the acousto-optic deflection element 152 so that when the focusing point movement control unit 62e moves the focusing point B in the first movement direction D1 and the second movement direction D2, the power of the laser beam A is reduced when the focusing point B is located in the outer edge region of the street 17 compared to when the focusing point B is located in the central region of the street 17.

[0101] Specifically, the acousto-optic deflection element 152 adjusts the power of laser beam A so that the power of laser beam A is lower when the focal point B is located at positions B26, B27, B28, and B29 compared to when the focal point B is located at positions B21, B22, B23, B24, and B25. For example, the power of laser beam A when the focal point B is located at positions B26, B27, B28, and B29 is adjusted to about 1% to 80% of the power of laser beam A when the focal point B is located at positions B21, B22, B23, B24, and B25.

[0102] As a result, a low-power laser beam A is irradiated onto the edge of the groove formed in street 17 with a high-power laser beam A, and debris such as recast materials attached to the edge of this groove is removed by the low-power laser beam A. In Figure 7, the positions B21, B22, B23, B24, B25, B26, B27, B28, and B29 of the focal point B are indicated by lines of thickness (width) corresponding to the power of laser beam A.

[0103] Furthermore, as shown in Figure 7, in this modified example, when the focusing point B moves in the second movement direction D2, the range of movement of the focusing point B in the first movement direction D1 is changed. For example, the focusing point movement control unit 62e controls the range of movement of the focusing point B in the first movement direction D1 such that the range of movement of the focusing point B in the first movement direction D1 is wider on the rear side compared to the front side in the direction in which the focusing point B and the chuck table 26 (i.e., the workpiece 11) move relative to each other.

[0104] More specifically, the range of movement of the focal point B in the first movement direction D1 is changed so that the positions B26, B27, B28, and B29 of the focal point B on the rear side (left side of Figure 7) are located further out than the positions B26, B27, B28, and B29 of the focal point B on the front side (right side of Figure 7), respectively. As a result, the low-power laser beam A illuminates a wider area in the direction of the width of the street 17, so that debris such as recasts adhering to the edges of the groove are removed more effectively by the low-power laser beam A.

[0105] However, there are no particular restrictions on the manner in which the focal point B is moved and the manner in which the power of the laser beam A is adjusted. For example, the focal point movement control unit 62e may move the focal point B from one position B28 (or the other position B29) on the outer edge, through the central position B21, to the other position B29 (or the other position B28) on the outer edge. Also, the laser power control unit 62f may adjust the power of the laser beam A using the acousto-optic deflection element 152 so that the power of the laser beam A decreases sequentially from the central position B21 to the outer edge positions B28 and B29.

[0106] Furthermore, the laser power control unit 62f may adjust the power of the laser beam A using the acousto-optic deflection element 152 so that the power of the laser beam A is lower at positions B26, B27, B28, and B29 of the focal point B on the rear side (left side of Figure 7), which are relatively further out than positions B26, B27, B28, and B29 of the focal point B on the front side (right side of Figure 7). In this case, debris such as recasts that may adhere to the edge of the groove on the front side, where the power of the laser beam A is relatively high, are appropriately removed by the lower-power laser beam A that irradiates a wider area (outer) on the rear side.

[0107] Furthermore, in the embodiments and modifications described above, the movement of the focal point B in the first movement direction D1 is achieved by the acousto-optic deflection element 48, but the movement of the focal point B in the first movement direction D1 may be achieved by a galvanometer scanner, resonant scanner, polygon scanner (polygon mirror), etc. Similarly, in the modifications described above, the movement of the focal point B in the second movement direction D2 is achieved by the polygon mirror 158, but the movement of the focal point B in the second movement direction D2 may be achieved by a galvanometer scanner, resonant scanner, acousto-optic deflection element, etc.

[0108] Furthermore, the structures, methods, etc., of the embodiments and modifications described above can be modified and implemented without departing from the scope of the objectives of the present invention. [Explanation of symbols]

[0109] 2: Laser processing equipment 4: Base 6: Horizontal movement mechanism (machining feed mechanism, indexing feed mechanism) 8: Y-axis guide rail 10: Y-axis moving plate 12: Screw shaft 14: Y-axis pulse motor 16: X-axis guide rail 18: X-axis movement plate 20: Screw shaft 22: X-axis pulse motor 24: Table base 26: Chuck table (holding unit) 26a: Holding surface 28: Clamp 30:Support structure 32: Vertical movement mechanism (height adjustment mechanism) 34: Z-axis guide rail 36: Z-axis movement plate 38: Z-axis pulse motor 40: Support 42: Laser beam irradiation unit 44: Laser oscillator 48: Acousto-optic deflection element (first focusing point shifting unit) 50: Housing 52: Irradiation head 54: Miller 56: Light concentrator 58: fθ lens 60: Camera (imaging unit) 62: Control Unit 62a: Rotation control unit 62b: X-axis movement control unit (machining feed control unit) 62c: Y-axis movement control unit (indexing feed control unit) 62d: Laser Oscillator Control Unit 62e: Focusing point movement control unit 62f: Laser power control unit 64: Processing Unit 66: Storage device 68: Touchscreen (input device, output device) 142: Laser beam irradiation unit 144: Laser oscillator 148: Miller 150: Miller 152: Acousto-optic deflection element (first focusing point shifting unit) 154: Miller 156: Miller 158: Polygon Mirror (Second Focusing Point Movement Unit) 160: Light concentrator 11: Workpiece 13: Tape 15: Frame 17: Street (Processing planned line) A: Laser beam B: Focus point D1: 1st movement direction D2 :Second movement direction

Claims

1. A laser processing apparatus that processes a workpiece by irradiating a laser beam onto a processing line having a predetermined width set on the workpiece, A holding unit for holding the workpiece, A laser beam irradiation unit that irradiates the workpiece held by the holding unit in such a way that the laser beam is focused onto the workpiece, A processing feed mechanism that moves the focusing point where the laser beam is focused and the holding unit relative to each other along the processing feed direction, The system comprises a processing unit and a storage device, and a control unit that controls the laser beam irradiation unit and the processing feed mechanism according to a program stored in the storage device, The laser beam irradiation unit is A laser oscillator that generates the laser beam, A focuser that focuses the laser beam generated by the laser oscillator onto the focal point, A first focusing point moving unit is positioned between the laser oscillator and the focusing device and moves the focusing point in a first movement direction intersecting the processing feed direction on the workpiece, The system includes a second focusing point moving unit, which is positioned between the laser oscillator and the focusing unit and moves the focusing point in a second movement direction intersecting the first movement direction on the workpiece, The control unit, in accordance with the program, A procedure for moving the focusing point and the holding unit relative to the processing feed direction, such that the direction of the width of the processing line is perpendicular to the processing feed direction, A procedure for moving the focusing point in the first movement direction within the width range of the planned processing line, as the focusing point and the holding unit move relative to each other along the processing feed direction, A procedure for moving the focusing point in the second movement direction when the focusing point and the holding unit move relative to each other along the processing feed direction, A procedure for controlling the power of a laser beam such that, as the focusing point moves in the first direction of movement, the power of the laser beam is reduced when the focusing point is located in the region on the outer edge of the processing line compared to when it is located in the region on the central side of the processing line; A laser processing apparatus for forming a groove in a processing line, comprising: a procedure for controlling the range of movement of the focusing point in the first direction of movement such that, when the focusing point moves in the second direction of movement, the range of movement of the focusing point in the first direction of movement is wider on the rear side than on the front side in the direction in which the focusing point and the holding unit move relative to each other.

2. A holding unit that holds a workpiece on which a processing line of a predetermined width is set, A laser beam irradiation unit that irradiates the workpiece held by the holding unit in such a way that the laser beam is focused onto the workpiece, A processing feed mechanism that moves the focusing point where the laser beam is focused and the holding unit relative to each other along the processing feed direction, The system comprises a processing unit and a storage device, and a control unit that controls the laser beam irradiation unit and the processing feed mechanism according to a program, The laser beam irradiation unit is A laser oscillator that generates the laser beam, A focuser that focuses the laser beam generated by the laser oscillator onto the focal point, A first focusing point moving unit is positioned between the laser oscillator and the focusing device and moves the focusing point in a first movement direction intersecting the processing feed direction on the workpiece, A program used when forming a groove in a planned processing line in a laser processing apparatus having a second focusing point moving unit positioned between the laser oscillator and the focusing unit, which moves the focusing point in a second moving direction intersecting the first moving direction on the workpiece, The program is A procedure for moving the focusing point and the holding unit relative to the processing feed direction, such that the direction of the width of the processing line is perpendicular to the processing feed direction, A procedure for moving the focusing point in the first movement direction within the width range of the planned processing line, as the focusing point and the holding unit move relative to each other along the processing feed direction, A procedure for moving the focusing point in the second movement direction when the focusing point and the holding unit move relative to each other along the processing feed direction, A procedure for controlling the power of a laser beam such that, as the focusing point moves in the first direction of movement, the power of the laser beam is reduced when the focusing point is located in the region on the outer edge of the processing line compared to when it is located in the region on the central side of the processing line; A program that causes the control unit to execute a procedure for controlling the range of movement of the focusing point in the first movement direction such that, when the focusing point moves in the second movement direction, the range of movement of the focusing point in the first movement direction is wider on the rear side than on the front side in the direction in which the focusing point and the holding unit move relative to each other.

3. A non-temporary recording medium on which the program described in claim 2 is recorded.

4. A holding unit that holds a workpiece on which a processing line of a predetermined width is set, A laser beam irradiation unit that irradiates the workpiece held by the holding unit in such a way that the laser beam is focused onto the workpiece, A method for processing a workpiece used when forming a groove in a planned processing line with a laser processing apparatus, comprising a processing feed mechanism that moves the focusing point where the laser beam is focused and the holding unit relative to each other along the processing feed direction, The steps include moving the focusing point and the holding unit relative to the processing feed direction, such that the direction of the width of the processing line is perpendicular to the processing feed direction, As the focusing point and the holding unit move relative to each other along the processing feed direction, the step of moving the focusing point in a first movement direction that intersects the processing feed direction within the width of the planned processing line, As the focusing point and the holding unit move relative to each other along the processing feed direction, the step of moving the focusing point in a second movement direction intersecting the first movement direction, A step of controlling the power of the laser beam such that, as the focusing point moves in the first direction of movement, the power of the laser beam is reduced when the focusing point is located in the region on the outer edge of the processing line compared to when it is located in the region on the central side of the processing line. A method for machining a workpiece, comprising the step of controlling the range of movement of the focusing point in the first movement direction such that, when the focusing point moves in the second movement direction, the range of movement of the focusing point in the first movement direction is wider on the rear side than on the front side in the direction in which the focusing point and the holding unit move relative to each other.

Images