Laser processing apparatus, laser processing method, laser processing program, recording medium, semiconductor chip manufacturing method, and semiconductor chip

Abstract

During execution of line processing (steps S1003 to S1004, S1103 to S1105) for processing a planned splitting line S by radiating a laser beam B onto a laser irradiation position Lb while moving the laser irradiation position Lb along the planned splitting line S, an imaging range Ri that moves relative to a semiconductor substrate W is imaged in order to acquire an image of a part of the semiconductor substrate W overlapped by the imaging range Ri (steps S1008 and S1104). In other words, a period in which the line processing is executed is utilized effectively for imaging of the semiconductor substrate W. In this way, imaging of the semiconductor substrate W can be performed efficiently in laser processing technology in which the laser beam B is radiated onto the planned splitting line S to process the planned splitting line S.

Description

[Technical field]

[0001] The present invention relates to a technique for processing a processing line provided on a processing object by irradiating the processing line with a laser beam. [Background technology]

[0002] Patent documents 1 to 3 describe a laser processing technique in which a dividing line provided on a semiconductor substrate is irradiated with a laser beam while the laser beam is moved relative to the semiconductor substrate to process the dividing line. For example, as shown in Patent document 1, in this laser processing technique, a plurality of dividing lines are processed in sequence by moving the laser beam back and forth while changing the dividing line to be irradiated with the laser beam in the forward and backward directions. At this time, the position of the laser beam is adjusted according to the result of an alignment process that recognizes the position of the dividing line based on an image acquired by imaging a predetermined portion of the semiconductor substrate, so that the dividing line can be accurately irradiated with the laser beam (Patent document 2). Also, as pointed out in Patent document 3, the width of the dividing line is expanded by processing the dividing line with the laser beam, and the position of the unprocessed dividing line may be shifted in the feed direction perpendicular to the processing direction. In order to deal with such a position shift of the dividing line, it is appropriate to appropriately perform imaging of the semiconductor substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5804716 [Patent Document 2] JP 5554593 A [Patent Document 3] JP 5037082 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned laser processing technology, it is required to efficiently capture images of the workpiece (semiconductor substrate) in order to recognize the influence of processing by irradiating the processing line (planned division line) with laser light.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a technology that enables efficient imaging of an object to be processed in a laser processing technology that irradiates a laser light onto a processing line to process the processing line. [Means for solving the problem]

[0006] The laser processing apparatus of the present invention includes a support member that supports a workpiece having a plurality of parallel processing lines so that the processing lines are parallel to a predetermined processing direction; a processing head that irradiates laser light at a predetermined laser irradiation position; a processing axis drive unit that moves the laser irradiation position relative to the workpiece in the processing direction by driving at least one of the support member and the processing head in the processing direction; a control unit that executes a line processing process to process the processing line by irradiating laser light to the laser irradiation position with the processing head while moving the laser irradiation position along the processing line with the processing axis drive unit; and an imaging unit that images a predetermined imaging range that moves relative to the workpiece integrally with the laser irradiation position as the laser irradiation position moves relative to the workpiece, and the imaging unit images the imaging range that moves relative to the workpiece during execution of the line processing process, thereby obtaining an image of a portion of the workpiece that overlaps with the imaging range.

[0007] The laser processing method of the present invention includes the steps of supporting a workpiece having a plurality of parallel processing lines with a support member so that the processing lines are parallel to a predetermined processing direction; performing a line processing process to process the processing lines by irradiating laser light to the laser irradiation position with the processing head while moving the laser irradiation position along the processing lines with a processing axis drive unit that moves the laser irradiation position relative to the workpiece in the processing direction by driving at least one of the processing head and the support member, which irradiates laser light to the predetermined laser irradiation position, in the processing direction; and performing an image processing process to obtain an image of a portion of the workpiece that overlaps with the imaging range, by an imaging unit that images a predetermined imaging range that moves relative to the workpiece integrally with the laser irradiation position as the laser irradiation position moves relative to the workpiece, by imaging the imaging range that moves relative to the workpiece during the execution of the line processing process.

[0008] In the present invention (laser processing device and laser processing method) configured in this manner, during execution of a line processing process in which the laser irradiation position is moved along the processing line and laser light is irradiated to the laser irradiation position to process the processing line, an image of the portion of the processing object that overlaps with the image capturing range is acquired by capturing an image of an image capturing range that moves relative to the processing object. In other words, the execution period of the line processing process is effectively utilized for capturing an image of the processing object. In this way, in the laser processing technology in which laser light is irradiated to the processing line to process the processing line, it is possible to efficiently capture an image of the processing object.

[0009] The laser processing device may be configured such that the imaging unit captures an image of an imaging range provided downstream in the direction in which the laser irradiation position moves relative to the processing line during line processing. In this configuration, an image of the unprocessed side of the position being processed by the laser light (i.e., the laser irradiation position) can be obtained. Therefore, the effect of processing by the laser light on the unprocessed portion of the object to be processed can be recognized based on the image.

[0010] The laser processing device may be configured such that the imaging unit captures images of the imaging range multiple times during one execution period of the line processing process. In this configuration, the execution period of the line processing process can be effectively utilized to obtain multiple images of the processing object.

[0011] The cutting machine further includes a feed axis drive unit that drives at least one of the support member and the machining head in a feed direction perpendicular to the machining direction to move the laser irradiation position relative to the workpiece in the feed direction, and the feed axis drive unit moves the laser irradiation position in the feed direction relative to the workpiece to change a machining line to be subjected to the line machining process among the plurality of machining lines. The control unit sequentially executes a first line machining process for machining a first machining line among the plurality of machining lines by a line machining process that moves the laser irradiation position to a first side in the machining direction, and a second line machining process for machining a second machining line different from the first machining line among the plurality of machining lines by a line machining process that moves the laser irradiation position to a second side opposite to the first side in the machining direction, and during a switching period from the end of the first line machining process to the start of the second line machining process, the machining axis drive unit passes the first machining line to the first side in the machining direction. the feed axis drive unit executes continuous feed drive for continuously moving the laser irradiation position in the feed direction from a first virtual straight line extending in the processing direction along the first processing line to an outside of the first processing line to a second virtual straight line extending in the processing direction along the second processing line to an outside of the second processing line; and the control unit controls the processing axis drive unit and the feed axis drive unit so that the feed axis drive unit starts the continuous feed drive before the processing axis drive unit stops the laser irradiation position by the reversal drive and ends the continuous feed drive after the processing axis drive unit stops the laser irradiation position by the reversal drive, thereby causing the feed axis drive unit to move the laser irradiation position in the feed direction before and after the movement of the laser irradiation position in the processing direction in the reversal drive stops.

[0012] In this configuration, a first line processing process for processing a first processing line and a second line processing process for processing a second processing line are performed using a processing axis drive unit that moves the laser irradiation position relative to the processing object in the processing direction and a feed axis drive unit that moves the laser irradiation position relative to the processing object in the feed direction. In addition, during a switching period between the first line processing process and the second line processing process, the processing axis drive unit and the feed axis drive unit perform the following operations to move the laser irradiation position that has passed the first processing line toward the second processing line. That is, the processing axis drive unit performs a reverse drive in the processing direction to decelerate and stop the laser irradiation position that has passed the first processing line toward the first side, and then accelerates it toward the second side, thereby causing the laser irradiation position to reach the second processing line. In addition, the feed axis drive unit moves the laser irradiation position in the feed direction from a first imaginary straight line extending in the processing direction along the first processing line to the outside of the first processing line to a second imaginary straight line extending in the processing direction along the second processing line to the outside of the second processing line.

[0013] In particular, the feed axis drive unit executes a continuous feed drive that continuously moves the laser irradiation position in the feed direction from the first virtual straight line to the second virtual straight line. The control unit controls the machining axis drive unit and the feed axis drive unit so that the feed axis drive unit starts the continuous feed drive before the machining axis drive unit stops the laser irradiation position by the reverse drive, and the feed axis drive unit ends the continuous feed drive after the machining axis drive unit stops the laser irradiation position by the reverse drive, and causes the feed axis drive unit to move the laser irradiation position in the feed direction before and after the movement of the laser irradiation position in the machining direction stops due to the reverse drive. In other words, during the switching period, both the period in which the laser irradiation position is decelerated to the first side in the machining direction and the period in which the laser irradiation position is accelerated to the second side in the machining direction are effectively used to move the laser irradiation position in the feed direction. As a result, it is possible to suppress the effect of the switching period in which the moving direction of the laser light is switched on the time required to complete processing of the workpiece. Furthermore, as described above, the period during which the line processing is being carried out is effectively utilized for capturing images of the workpieces to be processed, thereby reducing the time required to switch the processing line that is the subject of the line processing, and also enabling images of the workpieces to be captured efficiently, making it possible to quickly complete processing of the workpieces.

[0014] The imaging unit may be configured to image an imaging range including at least the processing line during line processing. In the image obtained by such imaging, the part corresponding to the processing line appears extended in the processing direction due to the contrast between the processing line and both sides of the processing line in the feed direction. Therefore, based on the position of the part in the feed direction, the effect of the laser processing on the position of the processing line in the feed direction can be accurately recognized.

[0015] The laser processing device may be configured so that the center of the imaging range of the imaging unit and the focal point of the laser light irradiated to the laser irradiation position are aligned in the processing direction. In this configuration, the state immediately before irradiation with the laser light can be accurately captured by the image of the imaging range.

[0016] The laser processing device may be configured such that, during the line processing of one target line among the multiple processing lines, the imaging unit acquires an image by imaging for the entire period during which the unprocessed portion of the target line that has not been processed by irradiating the laser light intersects with the imaging range, thereby obtaining information on the accumulated brightness of the image in the imaging range in the processing direction.

[0017] In addition, the exposure time Tc and the illumination intensity Tc during the entire period of imaging are expressed by the following relational expression with respect to the exposure time T0 and the illumination intensity L0 when the camera captures an image of a stationary processing object relative to the camera. Lc=T0×L0 / Tc The laser processing device may be configured to satisfy the following condition: With such a configuration, it is possible to prevent the luminance of the image from becoming saturated.

[0018] The control unit may be configured to determine whether the laser irradiation position is appropriate for the processing line based on the image acquired by the entire period image capturing. With this configuration, it is possible to check whether the laser irradiation position is appropriate.

[0019] The control unit may be configured to determine whether the laser irradiation position relative to the processing line is appropriate based on the central portion of the image excluding both ends in the orthogonal direction to the processing direction. In this configuration, the appropriateness of the laser irradiation position can be confirmed by excluding unnecessary information appearing at both ends of the image in the orthogonal direction.

[0020] The laser processing device may be configured such that, when the control unit confirms based on the image that the laser irradiation position is shifted in the orthogonal direction relative to the one target line, the control unit acquires the amount of positional deviation of the laser irradiation position in the orthogonal direction relative to the one target line, and corrects the laser irradiation position in the orthogonal direction based on the amount of positional deviation when performing line processing after the one target line. With such a configuration, the positional deviation of the laser irradiation position can be corrected to appropriately perform the line processing.

[0021] The control unit may be configured to perform alignment to correct the inclination of the trajectory of the laser irradiation position relative to one target line when the control unit checks the inclination of the trajectory of the laser irradiation position relative to one target line based on the image. In this configuration, the inclination of the laser irradiation position relative to the processing line can be corrected to appropriately perform the line processing process.

[0022] The semiconductor chip manufacturing method of the present invention includes a step of processing a semiconductor substrate on which a plurality of semiconductor chips are arranged and separated by a processing line, by the above-mentioned laser processing method, and a step of separating each of the plurality of semiconductor chips by expanding a tape that holds the semiconductor substrate processed by the laser processing method by its adhesive force.

[0023] The semiconductor chip of the present invention is manufactured by a step of processing a semiconductor substrate on which a plurality of semiconductor chips separated by processing lines are arranged, using the above-mentioned laser processing method, and a step of separating each of the plurality of semiconductor chips by expanding a tape that holds the semiconductor substrate processed by the laser processing method by its adhesive force.

[0024] A laser processing program according to the present invention causes a computer to execute the above-described laser processing method.

[0025] A recording medium according to the present invention records the above-mentioned laser processing program in a computer-readable manner. Effect of the Invention

[0026] According to the present invention, in a laser processing technique for processing a processing line by irradiating the processing line with laser light, it is possible to efficiently capture an image of an object to be processed. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a front view showing a schematic diagram of an example of a laser processing apparatus according to the present invention. [Diagram 2] FIG. 2 is a plan view showing a schematic diagram of the laser processing apparatus shown in FIG. [Diagram 3] 2 is a block diagram showing an electrical configuration of the laser processing apparatus of FIG. 1. [Figure 4] 1 is a flow chart illustrating an example of a method for producing a laser-processed substrate after laser processing has been performed. [Diagram 5] 11 is a flowchart showing an example of removing a ring frame. [Figure 6] 11 is a flowchart showing an example of transfer of a ring frame. [Figure 7A] FIG. 7 is a plan view showing a schematic example of an operation executed according to the flowcharts of FIGS. 5 and 6. [Figure 7B] FIG. 7 is a plan view showing a schematic example of an operation executed according to the flowcharts of FIGS. 5 and 6. [Figure 7C] FIG. 7 is a plan view showing a schematic example of an operation executed according to the flowcharts of FIGS. 5 and 6. [Figure 7D] FIG. 7 is a plan view showing a schematic example of an operation executed according to the flowcharts of FIGS. 5 and 6. [Figure 7E] FIG. 7 is a plan view showing a schematic example of an operation executed according to the flowcharts of FIGS. 5 and 6. [Figure 8] 10 is a flowchart showing an example of storing a ring frame. [Figure 9] 1 is a flowchart illustrating an example of ring frame alignment; [Figure 10] FIG. 11 is a plan view illustrating an example of an operation performed in ring frame alignment. [Figure 11] 4 is a flowchart showing an example of substrate processing. [Figure 12] 12 is a plan view showing an example of an operation executed according to the flowchart of FIG. 11. [Figure 13A] 11 is a flowchart showing an example of calibration. [Figure 13B] 13B is a flowchart showing an example of stage plane determination performed in the calibration of FIG. 13A. [Figure 13C]13B is a flowchart showing an example of substrate plane determination performed in the calibration of FIG. 13A. [Figure 14] 11 is a flowchart showing basic steps of a line processing process for each division line. [Figure 15A] 15 is a diagram showing a schematic diagram of a first example of the operation executed according to the flowchart of FIG. 14. [Figure 15B] 15 is a diagram illustrating a second example of the operation executed according to the flowchart of FIG. 14. [Figure 15C] FIG. 15 is a diagram illustrating a third example of the operation executed according to the flowchart of FIG. [Figure 15D] FIG. 15 is a diagram illustrating a fourth example of the operation executed according to the flowchart of FIG. [Figure 15E] FIG. 15 is a diagram illustrating a fifth example of the operation executed according to the flowchart of FIG. [Figure 15F] FIG. 15 is a diagram illustrating a sixth example of the operation executed according to the flowchart of FIG. [Figure 15G] FIG. 15 is a diagram illustrating a seventh example of the operation executed according to the flowchart of FIG. [Figure 16] 13 is a flowchart showing a first application example of line processing processing applied to each division line. [Figure 17] FIG. 17 is a diagram illustrating an example of the operation executed according to the flowchart of FIG. 16. [Figure 18] 13 is a flowchart showing a second application example of the line processing process applied to each division line. [Figure 19A] FIG. 20 is a diagram illustrating a first example of the operation executed according to the flowchart of FIG. 18. [Figure 19B] FIG. 20 is a diagram illustrating a second example of the operation executed according to the flowchart of FIG. 18. [Figure 20] 18. FIG. 21 is a diagram showing an example of an image of a semiconductor substrate acquired in step S1008 in FIG. 16 or step S1104 in FIG. [Figure 21] 11 is a flowchart showing an example of a method for determining laser processing conditions in a line processing process. [Figure 22A]FIG. 13 is a diagram showing parameters related to determining laser processing conditions. [Figure 22B] FIG. 13 is a diagram showing the effect of laser processing conditions over time. [Figure 22C] FIG. 22 is a diagram showing an example of a table to be referred to in determining the laser processing conditions in FIG. 21. [Figure 23] 11 is a plan view showing a schematic diagram of the positional relationship between the laser irradiation position and the imaging range in a detailed operation of imaging the imaging range. FIG. [Figure 24] FIG. 13 is a plan view showing a schematic diagram of an imaging target in a detailed operation for imaging an imaging range. [Diagram 25] 4 is a flowchart showing an example of exposure control of a camera. [Figure 26] 10A and 10B are diagrams illustrating information that can be acquired from a panning image captured by a panning operation. [Figure 27] 11 is a flowchart showing an example of image determination executed on a panning image. [Figure 28] FIG. 28 is a diagram showing a schematic diagram of a mask used in the image determination of FIG. 27 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Fig. 1 is a front view showing an example of a laser processing apparatus according to the present invention, and Fig. 2 is a plan view showing the laser processing apparatus of Fig. 1. In both figures and the following figures, the X direction, which is a horizontal direction, the Y direction, which is a horizontal direction perpendicular to the X direction, and the Z direction, which is a vertical direction, are shown as appropriate. Furthermore, the (+X) side of the X direction (the right side of the paper in Fig. 2) and the (-X) side opposite to the (+X) side of the X direction (the left side of the paper in Fig. 2) are shown as appropriate, and the (+Y) side of the Y direction (the upper side of the paper in Fig. 2) and the (-Y) side opposite to the (+Y) side of the Y direction (the lower side of the paper in Fig. 2) are shown as appropriate.

[0029] The laser processing device 1 processes the semiconductor substrate W (object to be processed) by irradiating the semiconductor substrate W with laser light. The semiconductor substrate W is held by a ring frame Fr via a tape E. The tape E is a dicing tape or a bonding tape, and the surface (upper surface) of the tape E is adhesive. The ring frame Fr has an outer shape in which a part of a regular octagon is cut out to provide a slit Fs, and a circular opening Fo is provided in the center of the ring frame Fr. The surface of the tape E faces the ring frame Fr from below so as to overlap the entire opening Fo, and the periphery of the surface of the tape E is attached to the bottom surface of the ring frame Fr by adhesive force. In addition, the semiconductor substrate W is attached to the surface of the tape E by adhesive force. In this way, the semiconductor substrate W is transported in the laser processing device 1 while being held by the ring frame Fr via the tape E. The semiconductor substrate W has a surface and a back surface opposite to the surface, and an electronic circuit is formed on the surface of the semiconductor substrate W, while the back surface of the semiconductor substrate W is flat. The front surface of the semiconductor substrate W faces downward and is attached to the front surface of the tape E. That is, the semiconductor substrate W is held in a state in which the back surface of the semiconductor substrate W faces upward.

[0030] The laser processing apparatus 1 includes a substrate accommodating section 2 that accommodates a semiconductor substrate W, and a chuck stage 3 (support member) that holds the semiconductor substrate W removed from the substrate accommodating section 2. The laser processing apparatus 1 includes a flat base plate 11, and the substrate accommodating section 2 and the chuck stage 3 are supported by the base plate 11. The chuck stage 3 is disposed on the (+X) side of the substrate accommodating section 2 in the X direction, and the chuck stage 3 is disposed on the (-Y) side of the substrate accommodating section 2 in the Y direction. The space on the (-X) side of the chuck stage 3 in the X direction and on the (-Y) side of the substrate accommodating section 2 in the Y direction becomes a substrate passing area Aw.

[0031] The substrate accommodating section 2 has a substrate accommodating cassette 21. The substrate accommodating cassette 21 has a pair of side walls 22 provided on both sides in the X direction and an opening 23 provided between the side walls 22, and the opening 23 faces the (-Y) side (i.e., the substrate transfer area Aw side). The pair of side walls 22 are flat plates provided perpendicular to the X direction and face each other in the X direction. In addition, a support protrusion 24 is provided on the inner side of each of the pair of side walls 22. Thus, the pair of support protrusions 24 facing each other in the X direction are provided at the same height. Then, a ring frame Fr that holds a semiconductor substrate W can be inserted into the upper side of the pair of support protrusions 24 from the (-Y) side through the opening 23. Both ends in the X direction of the ring frame Fr thus inserted are supported from below by the pair of support protrusions 24. That is, the upper sides of the pair of support protrusions 24 function as slots 25 that accommodate the ring frame Fr, and the ring frame Fr inserted into the slot 25 from the (-Y) side through the opening 23 is supported by the pair of support protrusions 24 that correspond to the slot 25. Therefore, by inserting the ring frame Fr into the slot 25 of the substrate accommodating cassette 21, the semiconductor substrate W supported by the ring frame Fr can be accommodated in the substrate accommodating cassette 21, and by pulling out the ring frame Fr from the slot 25 of the substrate accommodating cassette 21, the semiconductor substrate W can be removed from the substrate accommodating cassette 21.

[0032] Further, the substrate accommodating unit 2 has a Z-axis slider 26 that supports the substrate accommodating cassette 21, and a Z-axis drive mechanism 27 that drives the Z-axis slider 26 in the Z direction. The Z-axis drive mechanism 27 is a single-axis robot attached to the base plate 11, and has a Z-axis drive transmission unit 271 that supports the Z-axis slider 26 movably in the Z direction, and a Z-axis cassette motor 272 that drives the Z-axis slider 26 supported by the Z-axis drive transmission unit 271 in the Z direction. The Z-axis drive transmission unit 271 has a ball screw driven by the Z-axis cassette motor 272, and the Z-axis slider 26 is attached to a nut of the ball screw. However, the specific configuration of the Z-axis drive mechanism 27 is not limited to this example, and may be, for example, a linear motor. The Z-axis drive mechanism 27 drives the Z-axis slider 26 supported by the Z-axis drive transmission part 271 by the Z-axis cassette motor 272, thereby moving the substrate accommodation cassette 21 supported by the Z-axis slider 26 in the Z direction.

[0033] A substrate insertion height 211 is provided for the substrate accommodating cassette 21, and the semiconductor substrate W can be inserted into and withdrawn from the slot 25 located at the substrate insertion height 211. Therefore, by moving the substrate accommodating cassette 21 in the Z direction using the Z-axis drive mechanism 27 to change the slot 25 located at the substrate insertion height 211 among the multiple slots 25, the slot 25 into which the semiconductor substrate W is inserted and withdrawn can be changed.

[0034] In contrast, the laser processing apparatus 1 includes a Y-axis transport mechanism 4 that transports the ring frame Fr in the Y direction between the slot 25 at the substrate insertion height 211 and the substrate transfer area Aw. The Y-axis transport mechanism 4 includes a lift hand 41, a Y-axis slider 43 that supports the lift hand 41, and a Y-axis drive mechanism 45 that drives the Y-axis slider 43 in the Y direction. The Y-axis drive mechanism 45 is a single-axis robot attached to the base plate 11 by a frame as shown in the attached drawings, and includes a Y-axis drive transmission unit 451 that supports the Y-axis slider 43 movably in the Y direction, and a Y-axis lift hand motor 452 that drives the Y-axis slider 43 supported by the Y-axis drive transmission unit 451 in the Y direction. The Y-axis drive transmission unit 451 has a ball screw driven by the Y-axis lift hand motor 452, and the Y-axis slider 43 is attached to the nut of the ball screw. However, the specific configuration of the Y-axis drive mechanism 45 is not limited to this example, and may be, for example, a linear motor. The Y-axis drive mechanism 45 drives the Y-axis slider 43 supported by the Y-axis drive transmission part 451 with the Y-axis lift hand motor 452, thereby moving the lift hand 41 supported by the Y-axis slider 43 in the Y direction.

[0035] The lift hand 41 has a base part 411 supported by the Y-axis slider 43, and a fork 412 protruding from the base part 411 to the (+Y) side. The fork 412 is located at the substrate insertion height 211 and can hold the ring frame Fr from below. As will be described later, the Y-axis transport mechanism 4 drives the lift hand 41 in the Y direction using the Y-axis drive mechanism 45, thereby moving the ring frame Fr held by the fork 412 of the lift hand 41 between the substrate accommodation cassette 21 and the substrate transfer area Aw.

[0036] The laser processing apparatus 1 also includes an XZ-axis transport mechanism 5 that transports the ring frame Fr in the X direction between the lift hand 41 located in the substrate transfer area Aw and the chuck stage 3. The XZ-axis transport mechanism 5 includes a suction hand 51, an X-axis slider 53 that supports the suction hand 51, and an X-axis drive unit 55 that drives the X-axis slider 53 in the X direction. The X-axis drive unit 55 is a single-axis robot attached to the base plate 11 by a frame shown in the attached drawings, and includes an X-axis drive transmission unit 551 that supports the X-axis slider 53 movably in the X direction, and an X-axis suction hand motor 552 that drives the X-axis slider 53 supported by the X-axis drive transmission unit 551 in the X direction. The X-axis drive transmission unit 551 has a ball screw driven by the X-axis suction hand motor 552, and the X-axis slider 53 is attached to the nut of the ball screw. However, the specific configuration of the X-axis drive unit 55 is not limited to this example, and may be, for example, a linear motor. The X-axis drive unit 55 drives the X-axis slider 53 supported by the X-axis drive transmission unit 551 using the X-axis suction hand motor 552, thereby moving the suction hand 51 supported by the X-axis slider 53 in the X direction.

[0037] The XZ-axis transport mechanism 5 also includes a Z-axis slider 56 attached to the suction hand 51 and a Z-axis drive unit 58 that drives the Z-axis slider 56 in the Z direction relative to the X-axis slider 53. That is, the suction hand 51 is supported by the X-axis slider 53 via the Z-axis slider 56 and the Z-axis drive unit 58. The Z-axis drive unit 58 is a single-axis robot attached to the X-axis slider 53, and includes a Z-axis drive transmission unit 581 that supports the Z-axis slider 56 movably in the Z direction, and a Z-axis suction hand motor 582 that drives the Z-axis slider 56 supported by the Z-axis drive transmission unit 581 in the Z direction. The Z-axis drive transmission unit 581 has a ball screw driven by the Z-axis suction hand motor 582, and the Z-axis slider 56 is attached to the nut of the ball screw. However, the specific configuration of the Z-axis drive unit 58 is not limited to this example, and may be, for example, a linear motor. The Z-axis slider 56 extends from the Z-axis drive unit 58 to the lower side of the X-axis drive transmission unit 551, and the suction hand 51 is attached to the lower end of the Z-axis slider 56. The Z-axis drive unit 58 drives the Z-axis slider 56 supported by the Z-axis drive transmission unit 581 using a Z-axis suction hand motor 582, thereby moving the suction hand 51 supported by the Z-axis slider 56 in the Z direction.

[0038] The suction hand 51 has a base portion 511 supported by the Z-axis slider 56 and an annular suction member 512 protruding from the base portion 511 to the (+Y) side. The annular suction member 512 has an annular shape, and a plurality of suction holes are opened in a bottom surface 513 of the annular suction member 512. The ring frame Fr can be held from above by the suction hand 51 by sucking the ring frame Fr with negative pressure generated in each suction hole of the bottom surface 513 while the bottom surface 513 of the annular suction member 512 abuts against the ring frame Fr from above. As described later, the XZ-axis transport mechanism 5 drives the suction hand 51 in the X direction by the X-axis drive unit 55 and drives the suction hand 51 in the Z direction by the Z-axis drive unit 58, thereby moving the ring frame Fr held by the annular suction member 512 of the suction hand 51 between the substrate transfer area Aw and the chuck stage 3.

[0039] The chuck stage 3 has a suction plate 31 on which a ring frame Fr that supports the semiconductor substrate W via a tape E is placed. The suction plate 31 has a circular shape, and a plurality of suction holes are opened on an upper surface 311 of the suction plate 31. The tape E that contacts the upper surface 311 of the suction plate 31 is sucked by a negative pressure generated in each suction hole of the upper surface 311 of the suction plate 31, so that the tape E can be fixed to the suction plate 31. Furthermore, the chuck stage 3 has a plurality of clampers 32 provided on the periphery of the suction plate 31. The chuck stage 3 fixes the ring frame Fr to the suction plate 31 by making the clamper 32 face the ring frame Fr placed on the suction plate 31 from above and sandwiching the ring frame Fr between the clamper 32 and the suction plate 31. Moreover, the chuck stage 3 releases the ring frame Fr from being fixed to the suction plate 31 by retracting the clamper 32 to the side from the ring frame Fr.

[0040] In this manner, the chuck stage 3 holds the semiconductor substrate W supported on the ring frame Fr via the tape E by suction of the tape E by the suction plate 31 and fixing of the ring frame Fr by the clamper 32. By using the clamper 32 in this manner, the tape E can be sucked to the suction plate 31 with a weaker suction force than when the semiconductor substrate W is held only by suction of the tape E by the suction plate 31, and the effect of suction of the tape E on the semiconductor substrate W can be mitigated.

[0041] The laser processing apparatus 1 also includes an XYθ driving table 6 that supports the chuck stage 3. The XYθ driving table 6 is disposed on the base plate 11 and drives the chuck stage 3 in the X, Y and θ directions relative to the base plate 11. Here, the θ direction is a rotation direction centered on a rotation axis parallel to the Z direction. That is, the XYθ driving table 6 has a Y-axis guide 61 attached to the base plate 11 parallel to the Y direction, a Y-axis slider 62 supported by the Y-axis guide 61 so as to be movable in the Y direction, and a Y-axis driving unit 63 that drives the Y-axis slider 62 in the Y direction. The Y-axis driving unit 63 is a single-axis robot attached to the base plate 11, and has a Y-axis drive transmission unit 631 that supports the Y-axis slider 62 so as to be movable in the Y direction, and a Y-axis table motor 632 that drives the Y-axis slider 62 supported by the Y-axis drive transmission unit 631 in the Y direction. The Y-axis drive transmission unit 631 has a ball screw driven by a Y-axis table motor 632, and the Y-axis slider 62 is attached to the nut of the ball screw. However, the specific configuration of the Y-axis drive unit 63 is not limited to this example, and may be, for example, a linear motor.

[0042] Further, the XYθ drive table 6 has an X-axis slider 64 and an X-axis drive unit 65 that drives the X-axis slider 64 in the X direction relative to the Y-axis slider 62. The X-axis drive unit 65 is a single-axis robot attached to the Y-axis slider 62, and has an X-axis drive transmission unit 651 that supports the X-axis slider 64 movably in the X direction, and an X-axis table motor 652 that drives the X-axis slider 64 supported by the X-axis drive transmission unit 651 in the X direction. The X-axis drive transmission unit 651 has a ball screw driven by the X-axis table motor 652, and the X-axis slider 64 is attached to a nut of the ball screw. However, the specific configuration of the X-axis drive unit 65 is not limited to this example, and may be, for example, a linear motor.

[0043] Furthermore, the XYθ drive table 6 has a θ-axis table motor 66 attached to the X-axis slider 64. This θ-axis table motor 66 drives the chuck stage 3 relative to the X-axis slider 64 in the θ direction.

[0044] Such an XYθ drive table 6 can drive the chuck stage 3 in the Y direction by the Y-axis table motor 632, drive the chuck stage 3 in the X direction by the X-axis table motor 652, and drive the chuck stage 3 in the θ direction by the θ-axis table motor 66.

[0045] The laser processing device 1 also includes a laser processing unit 7 that performs laser processing on the semiconductor substrate W held on the chuck stage 3. The laser processing unit 7 has a processing head 71 that faces the semiconductor substrate W held on the chuck stage 3 from above. The processing head 71 has a laser light source 72 that generates laser light B of a predetermined frequency, and an optical system 73 (lens, diaphragm, etc.) that irradiates the semiconductor substrate W with the laser light B emitted from the laser light source 72. The processing head 71 has a predetermined laser irradiation position Lb and faces the laser irradiation position Lb from above in the Z direction. The processing head 71 collects the laser light B emitted from the laser light source 72 at the laser irradiation position Lb using the optical system 73, thereby forming a modified layer in a portion of the semiconductor substrate W that overlaps with the laser irradiation position Lb.

[0046] The laser processing unit 7 also has a Z-axis slider 78 that supports the processing head 71, and a Z-axis drive unit 79 that drives the Z-axis slider 78 in the Z direction. The Z-axis drive unit 79 is a single-axis robot attached to a base plate, and has a Z-axis drive transmission unit 791 that supports the Z-axis slider 78 movably in the Z direction, and a Z-axis head motor 792 that drives the Z-axis slider 78 supported by the Z-axis drive transmission unit 791 in the Z direction. The Z-axis drive transmission unit 791 has a ball screw driven by the Z-axis head motor 792, and the Z-axis slider 78 is attached to a nut of the ball screw. However, the specific configuration of the Z-axis drive unit 79 is not limited to this example, and may be, for example, a linear motor. The Z-axis drive unit 79 drives the Z-axis slider 78 supported by the Z-axis drive transmission unit 791 using the Z-axis head motor 792, thereby moving the processing head 71 supported by the Z-axis slider 78 in the Z direction and moving the laser irradiation position Lb of the infrared camera 81 in the Z direction.

[0047] The laser processing device 1 also includes an imaging section 8 that images the semiconductor substrate W held by the chuck stage 3. In particular, two imaging sections 8 are provided, arranged to sandwich the laser processing section 7 in the X direction. When distinguishing between these two imaging sections 8, the imaging section 8 on the (+X) side of the laser processing section 7 is referred to as imaging section 8A, and the imaging section 8 on the (-X) side of the laser processing section 7 is referred to as imaging section 8B. In this manner, the imaging section 8A, the laser processing section 7, and the imaging section 8B are arranged in the X direction. The imaging sections 8A and 8B have the same basic configuration. Therefore, the configuration common to the imaging sections 8A and 8B will be described without distinguishing between them.

[0048] The imaging unit 8 has an infrared camera 81 that faces from above the semiconductor substrate W held by the chuck stage 3. The infrared camera 81 has a predetermined imaging range Ri (in other words, a field of view) and faces the imaging range Ri from above in the Z direction. The infrared camera 81 detects infrared rays emitted from the imaging range Ri to capture an image of the imaging range Ri.

[0049] Moreover, the imaging unit 8 has a Z-axis slider 88 that supports the infrared camera 81, and a Z-axis drive unit 89 that drives the Z-axis slider 88 in the Z direction. The Z-axis drive unit 89 is a single-axis robot attached to a base plate, and has a Z-axis drive transmission unit 891 that supports the Z-axis slider 88 movably in the Z direction, and a Z-axis camera motor 892 that drives the Z-axis slider 88 supported by the Z-axis drive transmission unit 891 in the Z direction. The Z-axis drive transmission unit 891 has a ball screw driven by the Z-axis camera motor 892, and the Z-axis slider 88 is attached to a nut of the ball screw. However, the specific configuration of the Z-axis drive unit 89 is not limited to this example, and may be, for example, a linear motor. The Z-axis drive unit 89 drives the Z-axis slider 88 supported by the Z-axis drive transmission unit 891 using the Z-axis camera motor 892, thereby moving the infrared camera 81 supported by the Z-axis slider 88 in the Z direction and moving the imaging range Ri of the infrared camera 81 in the Z direction.

[0050] The infrared camera 81 of the imaging unit 8A and the infrared camera 81 of the imaging unit 8B have different resolutions. Specifically, the infrared camera 81 of the imaging unit 8A has a higher resolution than the infrared camera 81 of the imaging unit 8B, in other words, it has a narrower field of view. However, the resolution of the infrared camera 81 of the imaging unit 8A and the imaging unit 8B does not need to be different, and these infrared cameras 81 may have the same resolution. Also, in this example, the centers of the imaging range Ri of the imaging unit 8A, the laser irradiation position Lb of the processing head 71, and the imaging range Ri of the imaging unit 8B are aligned parallel to the X direction. However, these do not necessarily need to be parallel to the X direction, and it is sufficient that the imaging range Ri of the imaging unit 8A is located on the (+X) side and the imaging range Ri of the imaging unit 8B is located on the (-X) side with respect to the laser irradiation position Lb of the processing head 71.

[0051] Fig. 3 is a block diagram showing an electrical configuration of the laser processing apparatus of Fig. 1. As shown in Fig. 3, the laser processing apparatus 1 includes a control unit 100 that controls the configuration shown in Fig. 1 and Fig. 2. The control unit 100 includes a handling control calculation unit 110 in charge of controlling a substrate transport system (substrate accommodation unit 2, Y-axis transport mechanism 4, and XZ-axis transport mechanism 5) involved in transporting the semiconductor substrate W within the laser processing apparatus 1, and a laser processing control calculation unit 120 in charge of controlling a laser processing system (chuck stage 3, XYθ drive table 6, laser processing unit 7, and imaging unit 8) involved in laser processing of the semiconductor substrate W.

[0052] The control unit 100 also has a cassette control unit 111 that controls the insertion and removal operation of the semiconductor substrate W into and from the substrate accommodating cassette 21 in response to a command from the handling control calculation unit 110. The cassette control unit 111 adjusts the position of the substrate accommodating cassette 21 in the Z direction by controlling the Z-axis cassette motor 272, and adjusts the position of the lift hand 41 in the Y direction by controlling the Y-axis lift hand motor 452.

[0053] Furthermore, the control unit 100 has a hand control unit 112 that controls the transport operation of the semiconductor substrate W by the suction hand 51 in response to a command from the handling control calculation unit 110. The hand control unit 112 adjusts the position of the suction hand 51 in the X direction by controlling the X-axis suction hand motor 552, and the hand control unit 112 adjusts the position of the suction hand 51 in the Z direction by controlling the Z-axis suction hand motor 582. Furthermore, the hand control unit 112 controls a suction pump 591 that sucks the suction holes opening in the bottom surface 513 of the annular suction member 512 of the suction hand 51. That is, the hand control unit 112 causes the suction hand 51 to suck the ring frame Fr by supplying negative pressure to the suction holes by the suction pump 591, and causes the ring frame Fr to be separated from the suction hand 51 by stopping the supply of negative pressure to the suction holes by the suction pump 591.

[0054] The control unit 100 also has a stage control unit 121 that controls the substrate fixing operation by the chuck stage 3 and the driving of the chuck stage 3 in response to a command from the laser processing control calculation unit 120. The stage control unit 121 adjusts the position of the chuck stage 3 in the X-direction, the Y-direction, and the θ-direction by controlling the X-axis table motor 652, the Y-axis table motor 632, and the θ-axis table motor 66, respectively. Furthermore, the stage control unit 121 controls a clamper driving unit 691 that drives the clamper 32, thereby executing the fixing of the ring frame Fr to the suction plate 31 by the clamper driving unit 691 and the release of the fixing. Furthermore, the stage control unit 121 controls a suction pump 692 that sucks the suction holes opened in the upper surface 311 of the suction plate 31. That is, the stage control unit 121 causes the suction plate 31 to suction the tape E by supplying negative pressure to the suction holes by the suction pump 692, and releases the suction of the tape E by the suction plate 31 by stopping the supply of negative pressure to the suction holes by the suction pump 692.

[0055] The control unit 100 also has a camera control unit 122A that controls the imaging unit 8A, and a camera control unit 122B that controls the imaging unit 8B. These hand control units 112A, 112B execute the following control over the infrared camera 81 and Z-axis camera motor 892 of the imaging units 8A, 8B that are their respective targets. That is, each of the camera control units 122A, 122B causes the infrared camera 81 to capture an image of the semiconductor substrate W to obtain an image of the semiconductor substrate W, and adjusts the distance from the infrared camera 81 to the semiconductor substrate W in the Z direction by driving the infrared camera 81 in the Z direction with the Z-axis camera motor 892.

[0056] Furthermore, the control unit 100 has a processing head control unit 123 that controls the laser processing unit 7. The processing head control unit 123 drives the laser light source 72 to emit the laser light B from the laser light source 72, and drives the processing head 71 in the Z direction by the Z-axis head motor 792, thereby adjusting the distance from the processing head 71 to the semiconductor substrate W in the Z direction. Furthermore, the processing head 71 has a height detection unit 74 that detects the height (distance in the Z direction) from the semiconductor substrate W. This height detection unit 74 is a so-called distance sensor. Furthermore, the optical system 73 of the processing head 71 has a focus adjustment mechanism 75. The focus adjustment mechanism 75 adjusts the position at which the laser light B is focused by displacing the focus of the optical system 73 in the Z direction. In particular, the processing head control unit 123 controls the focus adjustment mechanism 75 based on the height from the semiconductor substrate W to the processing head 71 detected by the height detection unit 74, thereby focusing the laser light B at a predetermined position inside the semiconductor substrate W.

[0057] Each function of the control unit 100 described above is implemented by a processor such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gauge). This can be achieved by using a programmable gate array, etc.

[0058] Furthermore, the control unit 100 has a storage unit 190 which is a storage device such as a hard disk drive (HDD) or a solid state drive (SDD). A laser processing program 191 that specifies the operation to be executed by the laser processing device 1 for laser processing of the semiconductor substrate W is stored in the storage unit 190. That is, the control unit 100 executes each control to be described later with reference to Figs. 4 to 22C by executing the laser processing program 191. The laser processing program 191 is provided by a recording medium 192 external to the laser processing device 1, and the control unit 100 (computer) reads out the laser processing program 191 recorded in the recording medium 192 and stores it in the storage unit 190. Examples of such a recording medium 192 include a USB (Universal Serial Bus) memory and a storage device of an external computer.

[0059] Fig. 4 is a flow chart showing an example of a method for producing a laser-processed substrate after laser processing. The flow chart in Fig. 4 is executed according to the control of the control unit 100 based on the laser processing program 191. In step S101, the lift hand 41 takes out the ring frame Fr from the substrate accommodation cassette 21 to the substrate transfer area Aw, and in step S102, the suction hand 51 in the substrate transfer area Aw transfers the ring frame Fr from the lift hand 41 to the chuck stage 3. As a result, the semiconductor substrate W held by the ring frame Fr is taken out from the substrate accommodation cassette 21 to the substrate transfer area Aw, and then transferred from the substrate transfer area Aw to the chuck stage 3. Specifically, in step S101, the removal of the ring frame in Fig. 5 is executed, and in step S102, the transfer of the ring frame in Fig. 6 is executed.

[0060] FIG. 5 is a flowchart showing an example of removing a ring frame, FIG. 6 is a flowchart showing an example of transferring a ring frame, and FIGS. 7A to 7E are plan views showing typically an example of an operation performed according to the flowcharts of FIGS. 5 and 6.

[0061] In step S201 of Fig. 5, the control unit 100 checks whether the lift hand 41 is empty, i.e., whether a ring frame Fr is not placed on the lift hand 41. Whether the lift hand 41 is empty can be checked, for example, based on the history of operations performed by the lift hand 41. If the lift hand 41 is not empty (if "NO" in step S201), the flow chart of Fig. 5 ends, whereas if the lift hand 41 is empty (if "YES" in step S201), the process proceeds to step S201.

[0062] In step S202, the control unit 100 checks whether at least a part of the lift hand 41 is located inside the substrate storage cassette 21, in other words, whether it is located inside the substrate storage cassette 21 (i.e., on the (+Y) side) of the opening 23 of the substrate storage cassette 21. The check whether a part of the lift hand 41 is located inside the substrate storage cassette 21 can be performed based on the position of the lift hand 41 indicated by the output of the encoder of the Y-axis lift hand motor 452 that drives the lift hand 41 in the Y direction, for example. If the lift hand 41 has retreated to the (-Y) side from the substrate storage cassette 21 (if "NO" in step S202), the process proceeds to step S204 without executing step S203, whereas if a part of the lift hand 41 is located inside the substrate storage cassette 21 (if "YES" in step S202), the process proceeds to step S203. In step S203, the control unit 100 drives the lift hand 41 to the (-Y) side using the Y-axis lift hand motor 452, thereby pulling the lift hand 41 out from the substrate accommodating cassette 21 to the (-Y) side and retracting it to the (-Y) side of the substrate accommodating cassette 21.

[0063] In step S204, the control unit 100 drives the substrate accommodation cassette 21 in the Z direction using the Z-axis cassette motor 272, thereby positioning the slot 25 accommodating the ring frame Fr to be removed at a position a predetermined height higher than the substrate insertion height 211. This predetermined height is shorter than the distance between adjacent slots 25 in the Z direction. As a result, the bottom surface of the ring frame Fr to be removed is adjusted to a position a predetermined height higher than the lift hand 41.

[0064] 7A, in step S205, the control unit 100 drives the lift hand 41 to the (+Y) side by the Y-axis lift hand motor 452, thereby inserting the lift hand 41 into the inside of the substrate accommodating cassette 21. As a result, the lift hand 41 faces the ring frame Fr to be removed from below with a gap therebetween.

[0065] In step S206, the control unit 100 lowers the substrate storage cassette 21 in the Z direction by the Z-axis cassette motor 272. As a result, the ring frame Fr to be removed is placed on the lift hand 41 and is raised relative to the slot 25 (i.e., the pair of support protrusions 24 that define the slot 25).

[0066] In step S207, the control unit 100 drives the lift hand 41 to the (-Y) side by the Y-axis lift hand motor 452, thereby drawing out the lift hand 41 to the substrate passing area Aw provided outside the substrate accommodation cassette 21. As a result, the ring frame Fr placed on the lift hand 41 is positioned in the substrate passing area Aw, as shown in FIG. 7B.

[0067] 6, the control unit 100 adjusts the position of the suction hand 51 in the X direction by the X-axis suction hand motor 552, so that the suction hand 51 faces the ring frame Fr supported by the lift hand 41 in the substrate transfer area Aw from above, as shown in FIG. 7C. At this time, the control unit 100 adjusts the height of the suction hand 51 by the Z-axis suction hand motor 582, so that the suction hand 51 is positioned higher than the ring frame Fr. Therefore, the suction hand 51 faces the ring frame Fr with a gap therebetween.

[0068] In step S302, the control unit 100 lowers the suction hand 51 facing the ring frame Fr by the Z-axis drive transmission unit 581, and brings the bottom surface 513 of the suction hand 51 into contact with the upper surface of the ring frame Fr. In step S303, the control unit 100 generates negative pressure in the suction holes provided in the bottom surface 513 of the suction hand 51 by the suction pump 591, and the suction hand 51 adsorbs the ring frame Fr by this negative pressure. In this way, the ring frame Fr is held by the suction hand 51. In step S304, the control unit 100 raises the suction hand 51 by the Z-axis suction hand motor 582. As a result, the suction hand 51 lifts the ring frame Fr from the lift hand 41.

[0069] 7D, the control unit 100 drives the suction hand 51 to the (+X) side using the X-axis suction hand motor 552, thereby causing the suction hand 51 to face the chuck stage 3, to which the ring frame Fr is to be transferred, from above. At this time, the control unit 100 adjusts the height of the suction hand 51 using the Z-axis suction hand motor 582, thereby adjusting the ring frame Fr held by the suction hand 51 to a position higher than the chuck stage 3. Therefore, the ring frame Fr held by the suction hand 51 faces the chuck stage 3 with a gap therebetween.

[0070] In step S306, the control unit 100 lowers the suction hand 51 using the Z-axis suction hand motor 582, thereby placing the ring frame Fr (and the tape E) held by the suction hand 51 on the suction plate 31 of the chuck stage 3. In step S307, the control unit 100 stops the suction pump 591, and releases the suction of the ring frame Fr by the suction hand 51.

[0071] In step S308, the control unit 100 checks whether the destination of the ring frame Fr is the chuck stage 3. For example, if the destination of the ring frame Fr is the lift hand 41 as in step S104 described below, the determination in step S308 is "NO," and the flow chart in Fig. 6 ends. In this case, the destination of the ring frame Fr is the chuck stage 3, so the determination in step S308 is "YES," and the process proceeds to step S309.

[0072] In step S309, the control unit 100 drives the clamper 32 by the clamper driving unit 691, so that the ring frame Fr placed on the suction plate 31 of the chuck stage 3 is sandwiched between the clamper 32 and the suction plate 31, and the ring frame Fr is clamped. In step S310, the control unit 100 generates negative pressure in the suction holes provided on the upper surface 311 of the suction plate 31 by the suction pump 692, and the suction plate 31 uses this negative pressure to suction the tape E attached to the ring frame Fr. In this way, the ring frame Fr is held by the chuck stage 3. In step S311, the control unit 100 raises the suction hand 51 by the Z-axis suction hand motor 582. As a result, the suction hand 51 is retracted upward from the ring frame Fr held by the chuck stage 3. In this way, as shown in FIG. 7E, the transfer of the ring frame Fr from the substrate accommodation cassette 21 to the chuck stage 3 is completed (steps S101 and S102 in FIG. 4).

[0073] 4, substrate processing is performed in which the semiconductor substrate W held by the chuck stage 3 is processed with the laser light B, and the laser light B is irradiated onto a plurality of planned dividing lines provided on the semiconductor substrate W. Details of this substrate processing will be described later.

[0074] When the substrate processing is completed, steps S104 and S105 are executed. In step S104, the suction hand 51 transfers the ring frame Fr from the chuck stage 3 to the lift hand 41 in the substrate transfer area Aw, and in step S105, the lift hand 41 stores the ring frame Fr from the substrate transfer area Aw into the substrate accommodation cassette 21. As a result, the semiconductor substrate W held by the ring frame Fr is transferred from the chuck stage 3 to the substrate transfer area Aw, and then stored from the substrate transfer area Aw into the substrate accommodation cassette 21. Specifically, in step S104, the transfer of the ring frame in FIG. 6 is executed, and in step S105, the storage of the ring frame in FIG. 8 is executed, and the operations reverse to those in FIG. 7A to FIG. 7E described above are executed. Here, FIG. 8 is a flowchart showing an example of the storage of the ring frame.

[0075] The operation of FIG. 6 executed in step S104 is the same as the above-mentioned operation of FIG. 6 executed in step S102, so here, differences from the above-mentioned operation will be mainly described, and common operations will be omitted as appropriate. In step S301 of FIG. 6, the control unit 100 adjusts the position of the suction hand 51 in the X direction by the X-axis suction hand motor 552, so that the suction hand 51 faces the ring frame Fr placed on the chuck stage 3 from above. Then, the control unit 100 lowers the suction hand 51 to the ring frame Fr (step S302), and causes the suction hand 51 to suction the ring frame Fr (step S303). Next, the control unit 100 raises the suction hand 51 (step S304). As a result, the suction hand 51 lifts the ring frame Fr from the chuck stage 3.

[0076] In step S305, the control unit 100 drives the suction hand 51 to the (-X) side by the X-axis suction hand motor 552. At this time, the lift hand 41 is waiting in the substrate transfer area Aw, so that the suction hand 51 faces the lift hand 41 in the substrate transfer area Aw, which is the transfer destination of the ring frame Fr, from above. Then, the control unit 100 lowers the suction hand 51 by the Z-axis suction hand motor 582, thereby placing the ring frame Fr held by the suction hand 51 on the lift hand 41 (step S306). Then, the control unit 100 stops the suction pump 591 to release the suction of the ring frame Fr by the suction hand 51 (step S307). In step S308, the control unit 100 checks whether the transfer destination of the ring frame Fr is the chuck stage 3 or not. In this case, since the destination of the ring frame Fr is the lift hand 41 and not the chuck stage 3, the determination in step S308 is "NO," and the flow chart of FIG. 6 ends.

[0077] In step 401 of FIG. 8, the control unit 100 checks whether the ring frame Fr is placed on the lift hand 41. The check of placing the ring frame Fr on the lift hand 41 can be performed, for example, based on the operation history of the suction hand 51 that performs the placing of the ring frame Fr. When the placement of the ring frame Fr on the lift hand 41 is confirmed ("YES" in step S401), the control unit 100 checks whether at least a part of the lift hand 41 is located inside the substrate storage cassette 21 (step S402) in the same manner as in step S202 described above. If the lift hand 41 is retreated from the substrate storage cassette 21 to the (-Y) side ("NO" in step S402), the process proceeds to step S404 without executing step S403, whereas if a part of the lift hand 41 is located inside the substrate storage cassette 21 ("YES" in step S402), the process proceeds to step S403. In step S403, the control unit 100 drives the lift hand 41 to the (-Y) side using the Y-axis lift hand motor 452, thereby pulling the lift hand 41 out from the substrate accommodating cassette 21 to the (-Y) side and retracting it to the (-Y) side of the substrate accommodating cassette 21.

[0078] In step S404, the control unit 100 drives the substrate storage cassette 21 in the Z direction using the Z-axis cassette motor 272, thereby positioning the slot 25 (in other words, the pair of support protrusions 24 defining the slot 25) in which the ring frame Fr is to be stored, at a position a predetermined height lower than the substrate insertion height 211. As a result, the slot 25 in which the ring frame Fr is to be stored is adjusted to a position a predetermined height lower than the bottom surface of the ring frame Fr supported by the lift hand 41.

[0079] In step S405, the control unit 100 drives the lift hand 41 to the (+Y) side by the Y-axis lift hand motor 452, thereby inserting the lift hand 41 into the inside of the substrate storage cassette 21. As a result, the pair of support protrusions 24 that define the slot 25 to be stored face the ring frame Fr supported by the lift hand 41 from below with a gap therebetween.

[0080] In step S406, the control unit 100 raises the substrate storage cassette 21 in the Z direction using the Z-axis cassette motor 272. As a result, the ring frame Fr is placed on the pair of support protrusions 24 that define the slot 25 to be stored, and is raised relative to the lift hand 41. In step S407, the control unit 100 drives the lift hand 41 to the (-Y) side using the Y-axis lift hand motor 452, thereby drawing the lift hand 41 outward from the substrate storage cassette 21.

[0081] When the ring frame Fr is taken out or stored in the substrate accommodation cassette 21, ring frame alignment can be appropriately performed to align the ring frame Fr with respect to the lift hand 41. Fig. 9 is a flow chart showing an example of ring frame alignment, and Fig. 10 is a plan view showing a schematic example of an operation performed in the ring frame alignment. The flow chart in Fig. 9 is executed under the control of the control unit 100.

[0082] 10, the suction hand 51 is seen through to show the members (such as the alignment protrusions 413) below the suction hand 51. That is, in this example, the lift hand 41 has a plurality of alignment protrusions 413 protruding upward from the base portion 411. These alignment protrusions 413 correspond to the slits Fs of the ring frame Fr. Ring frame alignment is performed using the alignment protrusions 413 and the slits Fs.

[0083] In this ring frame alignment, the suction hand 51 suctions the ring frame Fr on the lift hand 41 (step S501). Then, the suction hand 51 holding the ring frame Fr rises to separate the ring frame Fr upward from the lift hand 41 (step S502). At this time, the height at which the ring frame Fr is separated from the lift hand 41 is adjusted so that the ring frame Fr is positioned at a height between the lower end and the upper end of the alignment protrusion 413 in the Z direction.

[0084] In step S503, the XYθ floating mechanism 561 built in the Z-axis slider 56 is turned on. This XYθ floating mechanism 561 selectively takes a floating state in which the suction hand 51 is floatingly supported, and a locked state in which the suction hand 51 is fixedly supported. Here, the floating support means that the suction hand 51 is supported in a state in which the suction hand 51 is movable in the X direction, the Y direction, and the θ direction relative to the XYθ floating mechanism 561, and the fixed support means that the suction hand 51 is supported in a state in which the suction hand 51 is fixed to the XYθ floating mechanism 561. When the XYθ floating mechanism 561 is turned on in step S503, the XYθ floating mechanism 561 floats the suction hand 51, and the suction hand 51 is movable in the X direction, the Y direction, and the θ direction relative to the XYθ floating mechanism 561.

[0085] In step S504, the lift hand 41 moves in the Y direction to bring the alignment protrusions 413 of the lift hand 41 into contact with the periphery of the ring frame Fr held by the suction hand 51. At this time, the suction hand 51 moves relative to the XYθ floating mechanism 561 so that the alignment protrusions 413 follow the periphery of the ring frame Fr. As a result, as shown in the column of step S504 in FIG. 10, each alignment protrusion 413 of the lift hand 41 engages with each slit Fs of the ring frame Fr, and the ring frame Fr is positioned relative to the lift hand 41.

[0086] In step S505, the XYθ floating mechanism 561 is locked. As a result, the suction hand 51 is fixedly supported by the XYθ floating mechanism 561. Then, in step S506, the suction hand 51 releases the ring frame Fr, and the ring frame Fr is placed on the lift hand 41. In step S507, the XYθ floating mechanism 561 is turned off, and the suction hand 51 is supported by the Z-axis slider 56 while being fixed to the Z-axis slider 56. In this way, the ring frame Fr can be positioned relative to the lift hand 41 (ring frame alignment).

[0087] Next, the details of the substrate processing will be described. Fig. 11 is a flowchart showing an example of the substrate processing, and Fig. 12 is a plan view showing a schematic example of an operation executed according to the flowchart of Fig. 11. The flowchart of Fig. 11 is executed under the control of the control unit 100.

[0088] In step S601 of the substrate processing in FIG. 11, a calibration is performed to obtain a plane of the upper surface (rear surface) of the semiconductor substrate W to be processed. FIG. 13A is a flow chart showing an example of the calibration, FIG. 13B is a flow chart showing an example of the stage plane determination performed in the calibration in FIG. 13A, and FIG. 13C is a flow chart showing an example of the substrate plane determination performed in the calibration in FIG. 13A. In the calibration in FIG. 13A, an image of the suction plate 31 or the semiconductor substrate W is appropriately taken. In the description here, it is assumed that the image is taken by the imaging unit 8B. However, even if the image is taken by the imaging unit 8A, the following operation can be similarly performed.

[0089] In step S701 of the calibration in Fig. 13A, stage plane identification (Fig. 13B) is performed. As shown in Fig. 13B, in the stage plane identification, a count value I for identifying a plurality of (three) imaging points Ps(I) provided on the upper surface 311 of the suction plate 31 of the chuck stage 3 is reset to zero (step S801), and the count value I is incremented by 1 (step S802). The imaging points Ps(I) are, for example, marks having a predetermined pattern.

[0090] In step S803, the control unit 100 adjusts the position of the chuck stage 3 using the XYθ drive table 6, thereby causing the imaging point Ps(I) to face the infrared camera 81 from below. This brings the imaging point Ps(I) into the field of view of the infrared camera 81. In step S803, the infrared camera 81 captures an image of the imaging point Ps(I) and obtains an image showing the imaging point Ps(I). In step S804, the control unit 100 checks whether a predetermined pattern of the imaging point Ps(I) can be detected from the image by image processing such as pattern matching.

[0091] If the focus of infrared camera 81 is shifted from imaging point Ps(I) and the predetermined pattern cannot be detected from the image ("NO" in step S804), control unit 100 drives infrared camera 81 in the Z direction using Z-axis camera motor 892 to change the distance of infrared camera 81 in the Z direction from imaging point Ps(I) (step S805). This changes the focus of infrared camera 81 in the Z direction. Steps S803 to S805 are repeated until infrared camera 81 focuses on imaging point Ps(I) and the predetermined pattern is detected ("YES" in step S804).

[0092] In step S806, the control unit 100 calculates the position (X, Y, Z) of the imaging point Ps(I) based on the predetermined pattern detected from the image acquired by imaging the imaging point Ps(I). The X and Y coordinates of the imaging point Ps(I) are calculated based on the position of the predetermined pattern included in the image. The Z coordinate of the imaging point Ps(I) is calculated based on the position in the Z direction of the infrared camera 81 when the image in which the predetermined pattern was detected was captured.

[0093] In step S807, it is confirmed whether the count value I has reached 2, i.e., whether the positions (X, Y, Z) of the two imaging points Ps(1) and Ps(2) have been acquired. If the count value I is less than 2 ("NO" in step S807), the process returns to step S802, and steps S802 to S806 are executed. If the count value I is 2 ("YES" in step S807), the process proceeds to step S808.

[0094] In step S808, a rotation angle θa is calculated for rotating the chuck stage 3 in the θ direction so that the straight line passing through the two imaging points Ps(1) and Ps(2) becomes horizontal. If the difference between the current rotation angle of the suction plate 31 (the actual rotation angle and the rotation angle θa) is not zero ("NO" in step S809), the chuck stage 3 is rotated by the rotation angle θa (step S810), and the process returns to step S801. In this manner, steps S801 to S809 are executed.

[0095] If the difference between the current rotation angle of the suction plate 31 (the actual rotation angle and the rotation angle θa) is zero (YES in step S809), the process proceeds to step S811. In step S811, the control unit 100 captures an image of the imaging point Ps(3) using the infrared camera 81 in the same manner as in step S803, and obtains an image showing the imaging point Ps(3). Then, in step S812, the control unit 100 checks whether a predetermined pattern of the imaging point Ps(3) can be detected from the image by image processing such as pattern matching.

[0096] If the predetermined pattern cannot be detected from the image (step S812: NO), control unit 100 changes the distance of infrared camera 81 in the Z direction from imaging point Ps(3) by driving infrared camera 81 in the Z direction using Z-axis camera motor 892 (step S813). Then, steps S811 to S813 are repeated until the predetermined pattern is detected (step S812: YES).

[0097] If the predetermined pattern is detected in step S812 (YES), the control unit 100 calculates the position (X, Y, Z) of the imaging point Ps(3) based on the predetermined pattern detected from the image acquired by imaging the imaging point Ps(3) (step S814). As a result, the positions (X, Y, Z) of the three imaging points Ps(1), Ps(2), and Ps(3) are acquired. In step S815, a plane passing through these three positions (X, Y, Z) is identified as the plane of the chuck stage 3, specifically, the plane representing the upper surface 311 of the suction plate 31.

[0098] In step S702 of the calibration in Fig. 13A, substrate plane identification (Fig. 13C) is performed. As shown in Fig. 13C, in the substrate plane identification, a count value I for identifying a plurality (three) of imaging points Pw(I) on the semiconductor substrate W is reset to zero (step S901), and the count value I is incremented by 1 (step S902). The imaging points Pw(I) are, for example, an area having a predetermined pattern.

[0099] Specifically, as shown in FIG. 12, the semiconductor substrate W is divided into a lattice shape by mutually orthogonal division lines S (Sa, Sb). That is, the semiconductor substrate W is provided with a plurality of parallel division lines Sa and a plurality of parallel division lines Sb, and the division lines Sa and Sb are orthogonal to each other. Thus, a plurality of semiconductor chips C are arranged in a lattice shape on either side of the division lines Sa and Sb. In contrast, an area including an intersection of the division lines Sa and Sb (in other words, a point surrounded by the semiconductor chips C arranged at the four corners) is set as the imaging point Pw(I). As described above, since the back surface of the semiconductor substrate W faces upward, the infrared camera 81 images the division lines Sa and Sb and the semiconductor chips C formed on the front surface of the semiconductor substrate W through the back surface of the semiconductor substrate W with infrared rays.

[0100] In step S903, the control unit 100 adjusts the position of the chuck stage 3 by the XYθ drive table 6, so that the imaging point Pw(I) faces the infrared camera 81 from below. This brings the imaging point Pw(I) into the field of view of the infrared camera 81. In step S903, the infrared camera 81 captures an image of the imaging point Pw(I) and obtains an image showing the imaging point Pw(I). In step S904, the control unit 100 checks whether a predetermined pattern of the imaging point Pw(I) (for example, a pattern where the planned division line Sa and the planned division line Sb intersect) can be detected from the image by image processing such as pattern matching.

[0101] If the focus of the infrared camera 81 is shifted from the imaging point Pw(I) and the predetermined pattern cannot be detected from the image ("NO" in step S904), the control unit 100 changes the distance of the infrared camera 81 in the Z direction from the imaging point Pw(I) by driving the infrared camera 81 in the Z direction using the Z-axis camera motor 892 (step S905). This changes the focus of the infrared camera 81 in the Z direction. Steps S903 to S905 are repeated until the infrared camera 81 focuses on the imaging point Pw(I) and the predetermined pattern is detected ("YES" in step S904).

[0102] Incidentally, a plane (stage plane) representing the upper surface 311 of the suction plate 31 has been specified by the previously executed stage plane specification ( FIG. 13B ). Therefore, the height range in which the imaging point Pw(I) of the semiconductor substrate W placed on the suction plate 31 exists can be estimated based on this stage plane. Therefore, in step S805, the height of the infrared camera 81 is changed so that the focus of the infrared camera 81 falls within the range in which the imaging point Pw(I) exists, which is estimated from the stage plane.

[0103] In step S906, the control unit 100 calculates the position (X, Y, Z) of the imaging point Pw(I) based on the predetermined pattern detected from the image acquired by imaging the imaging point Pw(I). The X and Y coordinates of the imaging point Pw(I) are calculated based on the position of the predetermined pattern included in the image. The Z coordinate of the imaging point Pw(I) is calculated based on the position in the Z direction of the infrared camera 81 when the image in which the predetermined pattern was detected was captured.

[0104] In step S907, it is confirmed whether the count value I has reached 2, i.e., whether the positions (X, Y, Z) of the two imaging points Pw(1) and Pw(2) have been acquired. If the count value I is less than 2 ("NO" in step S907), the process returns to step S902, and steps S902 to S906 are executed. If the count value I is 2 ("YES" in step S907), the process proceeds to step S908.

[0105] In step S908, a rotation angle θb for rotating the chuck stage 3 in the θ direction is calculated based on the two image capture points Pw(1) and Pw(2) so that the planned division line Sa is parallel to the X direction (machining direction). If the difference between the current rotation angle of the suction plate 31 (the actual rotation angle and the rotation angle θb) is not zero ("NO" in step S909), the chuck stage 3 is rotated by the rotation angle θb (step S910), and the process returns to step S901. In this manner, steps S901 to S909 are executed.

[0106] If the difference between the current rotation angle of the suction plate 31 (the actual rotation angle and the rotation angle θb) is zero (YES in step S909), the process proceeds to step S911. In step S911, the control unit 100 captures an image of the imaging point Pw(3) using the infrared camera 81 in the same manner as in step S903, and obtains an image showing the imaging point Pw(3). Then, in step S912, the control unit 100 checks whether a predetermined pattern of the imaging point Pw(3) can be detected from the image by image processing such as pattern matching.

[0107] If the predetermined pattern cannot be detected from the image (step S912: NO), the control unit 100 drives the infrared camera 81 in the Z direction by the Z-axis camera motor 892, thereby changing the distance of the infrared camera 81 in the Z direction from the imaging point Pw(3) (step S913). Then, steps S911 to S913 are repeated until the predetermined pattern is detected (step S912: YES). At this time, the range for changing the height of the infrared camera 81 is set based on the stage plane, as described above.

[0108] If the predetermined pattern is detected in step S912 (YES), the control unit 100 calculates the position (X, Y, Z) of the imaging point Pw(3) based on the predetermined pattern detected from the image acquired by imaging the imaging point Pw(3) (step S914). As a result, the positions (X, Y, Z) of the three imaging points Pw(1), Pw(2), and Pw(3) are acquired. In step S915, a plane passing through these three positions (X, Y, Z) is identified as a plane representing the semiconductor substrate W.

[0109] Returning to FIG. 11, the description will be continued. When the semiconductor substrate W is positioned so that the planned division lines Sa are parallel to the X direction by the execution of the above calibration, and a plane representing the semiconductor substrate W is specified (step S601), a line processing process (step S602) is executed for each planned division line Sa. That is, a line processing process is executed in which the laser irradiation position Lb is moved in the X direction along the target planned division line Sa and the laser light B is irradiated to the laser irradiation position Lb while changing the target planned division line Sa among the multiple planned division lines Sa, and processing is executed with the laser light B on each of the multiple planned division lines Sa. In particular, as shown in the column of step S602 in FIG. 12, a line processing process in which the laser irradiation position Lb is moved to the (+X) side in the X direction and a line processing process in which the laser irradiation position Lb is moved to the (-X) side in the X direction are executed alternately.

[0110] At this time, the movement of the laser light B to the (+X) side with respect to the dividing line Sa is performed by driving the chuck stage 3 holding the semiconductor substrate W to the (-X) side by the X-axis driving unit 65, and the movement of the laser light B to the (-X) side with respect to the dividing line Sa is performed by driving the chuck stage 3 holding the semiconductor substrate W to the (+X) side by the X-axis driving unit 65. In addition, the change of the dividing line Sa to be the target of the line processing is performed by driving the chuck stage 3 holding the semiconductor substrate W in the Y direction by the Y-axis driving unit 63. In addition, the control unit 100 controls the Z-axis camera motor 892 to adjust the position of the infrared camera 81 in the Z direction based on the plane representing the semiconductor substrate W specified by the calibration in step S601. As a result, the focusing position of the laser light B is adjusted inside the semiconductor substrate W, and a modified layer is formed inside the semiconductor substrate W along the dividing line Sa.

[0111] In this way, when the line processing for each of the plurality of planned division lines Sa is completed (step S602), the chuck stage 3 holding the semiconductor substrate W is rotated by 90 degrees in the θ direction by the θ-axis table motor 66. This switches the state from one in which the plurality of planned division lines Sa on which the laser processing has been performed are positioned parallel to the X direction (the column "S602_e" in FIG. 12) to one in which the plurality of planned division lines Sb are positioned parallel to the X direction (the column "S603" in FIG. 12).

[0112] In step S604, calibration is performed in the same manner as in step S601 described above. Also, in step S605, line processing is performed on each of the plurality of planned division lines Sb in the same manner as in step S602 described above.

[0113] Fig. 14 is a flow chart showing basic steps of line processing for each division line, and Fig. 15A is a diagram showing a first example of the operation executed according to the flow chart of Fig. 14. In Fig. 15A, the locus of the laser irradiation position Lb that moves relatively to the semiconductor substrate W is shown by a dotted line, and virtual straight lines Sv1, Sv2, Sv3 extending parallel to the X direction between both outer sides of the division lines S1, S2, S3 along the division lines S1, S2, S3 are shown by a dashed line. Note that in the part where the locus of the laser irradiation position Lb and the virtual straight lines Sv1, Sv2, Sv3 overlap, the dotted line showing the locus of the laser irradiation position Lb is preferentially shown.

[0114] In the example shown in Fig. 15A, the flow chart of Fig. 14 starts from a state in which the laser irradiation position Lb is stopped at a position Pb1 on the (-X) side of the semiconductor substrate W in the X direction. This position Pb1 is provided on a virtual straight line Sv1 along the planned division line S1, in other words, a position facing the planned division line S1 from the X direction. However, the position of the laser irradiation position Lb when starting the flow chart of Fig. 14 is not limited to this example and can be changed as appropriate.

[0115] In step S1001, the laser irradiation position Lb, which stops at position Pb1, starts accelerating toward the (+X) side in the X direction and moves parallel to the X direction. This causes the laser irradiation position Lb to move toward the (+X) side along the virtual straight line Sv1. Then, when the speed Vx of the laser irradiation position Lb increases to a processing speed Vxd before the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (-X) side, the laser irradiation position Lb moves at a constant speed toward the (+X) side in the X direction at the processing speed Vxd (step S1002).

[0116] Furthermore, in synchronization with the timing when the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (-X) side, the laser light source 72 is turned on, and irradiation of the laser light B from the processing head 71 to the laser irradiation position Lb is started (step S1003). In addition, in synchronization with the timing when the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser light source 72 is turned off, and irradiation of the laser light B from the processing head 71 to the laser irradiation position Lb is terminated (step S1004). Thus, during the period from step S1003 to S1004, the laser irradiation position Lb is irradiated with the laser light B while the laser irradiation position Lb moves along the planned division line S1 to the (+X) side, and laser processing is performed on the planned division line S1 (line processing process).

[0117] When the laser irradiation position Lb passes the planned dividing line S1 on the (+X) side, the laser irradiation position Lb starts to decelerate toward the (+X) side in the X direction (step S1005), and the laser irradiation position Lb stops at a position Pb2 on the (+X) side of the semiconductor substrate W in the X direction (step S1006). This position Pb2 is provided on the virtual line Sv2 adjacent to the virtual line Sv1 in the Y direction, in other words, a position facing the planned dividing line S2 from the X direction. That is, in steps S1005 to S1006, the laser irradiation position Lb moves in the Y direction from the virtual line Sv1 to the virtual line Sv2 in parallel with the deceleration in the X direction.

[0118] Incidentally, the positional relationship between the imaging range Ri (FIG. 1) of the imaging units 8A and 8B and the laser irradiation position Lb of the processing head 71 is fixed. Therefore, in steps S1001 to S1006, as the laser irradiation position Lb moves relative to the semiconductor substrate W, the imaging range Ri also moves relative to the semiconductor substrate W. Then, in a state where the laser irradiation position Lb stops at the position Pb2, the imaging range Ri of the imaging unit 8B stops at a position including at least the imaging point Pw (S2). This imaging point Pw (S2) is an intersection point where the planned division line S2 and the planned division line S perpendicular to the planned division line S intersect on the semiconductor substrate W. Therefore, in step S1006, the control unit 100 causes the imaging unit 8B to image the imaging range Ri to obtain an image including the imaging point Pw (S2). As a result, the control unit 100 can obtain an image showing the position of the planned division line S2 that is not yet processed.

[0119] In step S1007, it is confirmed whether or not laser processing has been completed for a plurality of division lines S parallel to the X direction. If there are any unprocessed division lines S among these division lines S (if "NO" in step S1007), the process returns to step S1001.

[0120] 15A, in step S1001, the laser irradiation position Lb stopped at position Pb2 starts accelerating toward the (-X) side in the X direction and moves parallel to the X direction. This causes the laser irradiation position Lb to move toward the (-X) side along the virtual straight line Sv2. Then, when the speed Vx of the laser irradiation position Lb increases to a processing speed Vxd before the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser irradiation position Lb moves at a constant speed toward the (-X) side in the X direction at the processing speed Vxd (step S1002).

[0121] Here, in the X direction, the position where the laser irradiation position Lb that has passed the planned division line S1 to the (+X) side starts to decelerate (in other words, the X coordinate where the uniform speed movement to the (+X) side ends) coincides with the position where the laser irradiation position Lb that accelerates to the (-X) side toward the planned division line S ends its acceleration (in other words, the X coordinate where the uniform speed movement to the (-X) side starts) coincides with the X direction where the laser irradiation position Lb that has passed the planned division line Sn on which the nth line processing is performed ends its uniform speed movement and starts to decelerate, and coincides with the X direction where the laser irradiation position Lb toward the planned division line Sn+1 on which the n+1th line processing is performed ends its acceleration and starts its uniform speed movement.

[0122] Furthermore, in synchronization with the timing when the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser light source 72 is turned on, and irradiation of the laser light B from the processing head 71 to the laser irradiation position Lb is started (step S1003). In addition, in synchronization with the timing when the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (-X) side, the laser light source 72 is turned off, and irradiation of the laser light B from the processing head 71 to the laser irradiation position Lb is terminated (step S1004). Thus, during the period from step S1003 to S1004, the laser irradiation position Lb is irradiated with the laser light B while the laser irradiation position Lb moves along the planned division line S2 to the (-X) side, and laser processing is performed on the planned division line S2 (line processing process).

[0123] When the laser irradiation position Lb passes the planned dividing line S2 on the (-X) side, the laser irradiation position Lb starts to decelerate toward the (-X) side in the X direction (step S1005), and the laser irradiation position Lb stops at a position Pb3 on the (-X) side of the semiconductor substrate W in the X direction (step S1006). This position Pb3 is provided on the virtual line Sv3 adjacent to the virtual line Sv2 in the Y direction, in other words, a position facing the planned dividing line S3 from the X direction. That is, in steps S1005 to S1006, the laser irradiation position Lb moves in the Y direction from the virtual line Sv2 to the virtual line Sv3 in parallel with the deceleration in the X direction.

[0124] Moreover, in a state where the laser irradiation position Lb stops at the position Pb3, the imaging range Ri of the imaging unit 8A stops at a position including at least the imaging point Pw (S3). This imaging point Pw (S3) is an intersection of the planned division line S3 and the planned division line S perpendicular to the planned division line S on the semiconductor substrate W. Therefore, in step S1006, the control unit 100 causes the imaging unit 8A to image the imaging range Ri to obtain an image including the imaging point Pw (S3). This allows the control unit 100 to obtain an image showing the position of the unprocessed planned division line S3.

[0125] Then, steps S1001 to S1007 are repeated until it is confirmed that the laser processing is completed for a plurality of planned division lines S (S1, S2, S3, . . . ) parallel to the X direction ("YES" in step S1007).

[0126] Next, the speed change of the laser irradiation position Lb will be described with reference to "speed change in X direction" and "speed change in Y direction" in Fig. 15A. Here, the speed Vx indicates the speed at which the laser irradiation position Lb moves in the X direction relative to the semiconductor substrate W, and the speed Vy indicates the speed at which the laser irradiation position Lb moves in the Y direction relative to the semiconductor substrate W. Moreover, the processing speed Vxd indicates the speed at which the laser irradiation position Lb moves at a constant speed in the X direction along the intended division line S (i.e., the speed Vx), and is expressed as an absolute value regardless of whether the laser irradiation position Lb moves to the (+X) side or the (-X) side.

[0127] In a line processing period Ts1 (steps S1002 to S1004) in which a line processing process is performed to move the laser light B to the (+X) side along the planned division line S1, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction. Also, in a line processing period Ts2 (steps S1002 to S1004) in which a line processing process is performed to move the laser light B to the (-X) side along the planned division line S2, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction.

[0128] In addition, during a switching period Tc (steps S1005, S1006, S1001) when the line processing period Ts1 is switched to the line processing period Ts2, the following operation is executed. That is, the X-axis drive unit 65 (processing axis drive unit) decelerates the laser irradiation position Lb that has passed the division line S1 (first processing line) toward the (+X) side (first side) in the X direction (processing direction) toward the (+X) side, stops it (step S1005), and then accelerates it toward the (-X) side (step S1001), thereby executing a reversal drive to bring the laser irradiation position Lb to the division line S2 (second processing line). In parallel with this reversal drive, the Y-axis drive unit 63 (feed axis drive unit) moves the laser irradiation position Lb in the Y direction (feed direction) from a virtual straight line Sv1 (first virtual straight line) extending in the X direction along the planned division line S1 to the outside of the planned division line S1 to a virtual straight line Sv2 (second virtual straight line) extending in the X direction along the planned division line S2 (second processing line) to the outside of the planned division line S2.

[0129] In particular, the switching period Tc includes a deceleration period Td (step S1005) in which the laser irradiation position Lb is decelerated in the X direction, and an acceleration period Ta (step S1001) in which the laser irradiation position Lb is accelerated in the X direction, and the movement of the laser irradiation position Lb in the Y direction is executed during the deceleration period Td out of the deceleration period Td and the acceleration period Ta. Specifically, the movement of the laser irradiation position Lb in the Y direction starts after the deceleration period Td starts, and the movement of the laser irradiation position Lb in the Y direction ends before the deceleration period Td ends. Moreover, the laser irradiation position Lb does not move in the Y direction during the acceleration period Ta.

[0130] Here, the start of the deceleration period Td indicates the time when the laser irradiation position Lb starts to decelerate in the X direction (in other words, the absolute value of the speed Vx decreases from the processing speed Vxd), and the end of the deceleration period Td indicates the time when the speed of the laser irradiation position Lb in the X direction (in other words, the speed Vx) becomes zero. The start of the acceleration period Ta indicates the time when the laser irradiation position Lb starts to accelerate in the X direction (in other words, the absolute value of the speed Vx increases from zero), and the end of the acceleration period Ta indicates the time when the acceleration of the laser irradiation position Lb in the X direction ends (in other words, the absolute value of the speed Vx becomes the processing speed Vxd).

[0131] During a stop period Tt provided during the transition from the acceleration period Ta to the deceleration period Td, both the velocity Vx in the X direction and the velocity Vy in the Y direction of the laser irradiation position Lb become zero, and the laser irradiation position Lb stops at position Pb2 relative to the semiconductor substrate W. During this stop period Tt, the imaging range Ri of the imaging units 8A and 8B also stops relative to the semiconductor substrate W, and in particular, the imaging range Ri of the imaging unit 8B is located on the (-X) side of the laser irradiation position Lb located on the (+X) side of the semiconductor substrate W, overlapping with the semiconductor substrate W. Therefore, during the stop period Tt, the infrared camera 81 of the imaging unit 8B images a portion of the semiconductor substrate W that overlaps with the imaging range Ri (step S1006).

[0132] FIG. 15B is a diagram showing a second example of the operation performed according to the flowchart of FIG. 14. The notation in FIG. 15B is the same as that in FIG. 15A. In FIG. 15B, the laser processing is performed in order on the division lines S1, S2, and S3 according to the flowchart of FIG. 14, as in FIG. 15A. However, the operation in the switching period Tc for changing the division line S to be subjected to the laser processing is different between FIG. 15B and FIG. 15A. Therefore, the difference from FIG. 15A will be mainly described, and the common operations will be denoted by corresponding symbols and the description thereof will be omitted as appropriate.

[0133] When the laser irradiation position Lb passes the planned division line S1 toward the (+X) side with the end of the laser processing on the planned division line S1, the laser irradiation position Lb starts to decelerate toward the (+X) side in the X direction (step S1005), and the laser irradiation position Lb stops at a position Pb2 on the (+X) side of the semiconductor substrate W in the X direction (step S1006). This position Pb2 is provided on the virtual straight line Sv1. In addition, in a state where the laser irradiation position Lb stops at the position Pb2, the imaging range Ri of the imaging unit 8B stops at a position that includes at least the imaging point Pw (S2). Therefore, in step S1006, the control unit 100 causes the imaging unit 8B to image the imaging range Ri to obtain an image including the imaging point Pw (S2). As a result, the control unit 100 can obtain an image showing the position of the unprocessed planned division line S2.

[0134] Next, the laser irradiation position Lb, which stops at the position Pb2, starts accelerating toward the (-X) side in the X direction (step S1001). Then, when the speed Vx of the laser irradiation position Lb increases to the processing speed Vxd before the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser irradiation position Lb moves at a constant speed toward the (-X) side in the X direction at the processing speed Vxd (step S1002). In addition, during the period from when the laser irradiation position Lb starts accelerating to when it starts moving at a constant speed at the processing speed Vxd, the laser irradiation position Lb moves in the Y direction from the virtual straight line Sv1 to the virtual straight line Sv2. That is, in steps S1001 to S1002, the laser irradiation position Lb moves in the Y direction from the virtual straight line Sv1 to the virtual straight line Sv2 in parallel with the acceleration in the X direction. As a result, the laser irradiation position Lb reaches the planned division line S2, and line processing on the planned division line S2 can be started.

[0135] When the laser irradiation position Lb passes the planned division line S2 to the (-X) side with the end of the laser processing on the planned division line S2, the laser irradiation position Lb starts to decelerate toward the (-X) side in the X direction (step S1005), and the laser irradiation position Lb stops at a position Pb3 on the (-X) side of the semiconductor substrate W in the X direction (step S1006). This position Pb3 is provided on the virtual straight line Sv2. In addition, in a state where the laser irradiation position Lb stops at the position Pb3, the imaging range Ri of the imaging unit 8A stops at a position that includes at least the imaging point Pw (S3). Therefore, in step S1006, the control unit 100 causes the imaging unit 8A to image the imaging range Ri to obtain an image including the imaging point Pw (S3). As a result, the control unit 100 can obtain an image showing the position of the unprocessed planned division line S3.

[0136] Next, the speed change of the laser irradiation position Lb will be described with reference to "speed change in X direction" and "speed change in Y direction" in Fig. 15B. In a line processing period Ts1 (steps S1002 to S1004) in which a line processing process is performed to move the laser light B to the (+X) side along the division line S1, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction. In addition, in a line processing period Ts2 (steps S1002 to S1004) in which a line processing process is performed to move the laser light B to the (-X) side along the division line S2, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction.

[0137] Also, in a switching period Tc (steps S1005, S1006, S1001) in which the line processing period Ts1 is switched to the line processing period Ts2, the laser irradiation position Lb is moved in the Y direction (feed direction) from the virtual straight line Sv1 to the virtual straight line Sv2 in parallel with the inversion drive in the X direction as described above. In particular, of the deceleration period Td and acceleration period Ta included in the switching period Tc, the movement of the laser irradiation position Lb in the Y direction is executed during the acceleration period Ta. Specifically, the movement of the laser irradiation position Lb in the Y direction starts after the acceleration period Ta starts, and the movement of the laser irradiation position Lb in the Y direction ends before the acceleration period Ta ends. Moreover, the laser irradiation position Lb does not move in the Y direction during the deceleration period Td.

[0138] During a stop period Tt provided during the transition from the acceleration period Ta to the deceleration period Td, both the velocity Vx in the X direction and the velocity Vy in the Y direction of the laser irradiation position Lb become zero, and the laser irradiation position Lb stops at position Pb2 relative to the semiconductor substrate W. During this stop period Tt, the imaging range Ri of the imaging units 8A and 8B also stops relative to the semiconductor substrate W, and in particular, the imaging range Ri of the imaging unit 8B is located on the (-X) side of the laser irradiation position Lb located on the (+X) side of the semiconductor substrate W, overlapping with the semiconductor substrate W. Therefore, during the stop period Tt, the infrared camera 81 of the imaging unit 8B images a portion of the semiconductor substrate W that overlaps with the imaging range Ri (step S1006).

[0139] FIG. 15C is a diagram showing a third example of the operation performed according to the flowchart of FIG. 14. The notation in FIG. 15C is the same as that in FIG. 15A. In FIG. 15C, the laser processing is performed in order on the division lines S1, S2, and S3 according to the flowchart of FIG. 14, as in FIG. 15A. However, the operation in the switching period Tc for changing the division line S to be subjected to the laser processing is different between FIG. 15C and FIG. 15A. Therefore, the difference from FIG. 15A will be mainly described, and the common operations will be denoted by corresponding symbols and the description will be omitted as appropriate.

[0140] When the laser irradiation position Lb passes the division line S1 on the (+X) side with the completion of the laser processing on the division line S1, the laser irradiation position Lb starts to decelerate toward the (+X) side in the X direction (step S1005), and the laser irradiation position Lb stops at a position Pb2 on the (+X) side of the semiconductor substrate W in the X direction (step S1006). This position Pb2 is provided between the virtual straight lines Sv1 and Sv2 in the Y direction. That is, in steps S1005 to S1006, the laser irradiation position Lb moves in the Y direction from the virtual straight line Sv1 to the position Pb2 in parallel with the deceleration in the X direction. In addition, when the laser irradiation position Lb stops at the position Pb2, the imaging range Ri of the imaging unit 8B stops at a position including at least the imaging point Pw(S2). Therefore, in step S1006, the control unit 100 causes the imaging unit 8B to capture the imaging range Ri and obtain an image including the imaging point Pw(S2). This allows the control unit 100 to obtain an image indicating the position of the unprocessed planned division line S2.

[0141] Next, the laser irradiation position Lb, which stops at the position Pb2, starts accelerating toward the (-X) side in the X direction (step S1001). Then, when the speed Vx of the laser irradiation position Lb increases to the processing speed Vxd before the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser irradiation position Lb moves at a constant speed toward the (-X) side in the X direction at the processing speed Vxd (step S1002). In addition, during the period from when the laser irradiation position Lb starts accelerating to when it starts moving at a constant speed at the processing speed Vxd, the laser irradiation position Lb moves in the Y direction from the position Pb2 to the virtual straight line Sv2. That is, in steps S1001 to S1002, the laser irradiation position Lb moves in the Y direction from the position Pb2 to the virtual straight line Sv2 in parallel with the acceleration in the X direction. As a result, the laser irradiation position Lb reaches the planned division line S2, and line processing on the planned division line S2 can be started.

[0142] When the laser irradiation position Lb passes the planned division line S2 on the (-X) side with the completion of the laser processing on the planned division line S2, the laser irradiation position Lb starts to decelerate toward the (-X) side in the X direction (step S1005), and the laser irradiation position Lb stops at a position Pb3 on the (-X) side of the semiconductor substrate W in the X direction (step S1006). This position Pb3 is provided between the virtual straight lines Sv2 and Sv3 in the Y direction. That is, in steps S1005 to S1006, the laser irradiation position Lb moves in the Y direction from the virtual straight line Sv2 to position Pb3 in parallel with the deceleration in the X direction. In addition, when the laser irradiation position Lb stops at position Pb3, the imaging range Ri of the imaging unit 8A stops at a position including at least the imaging point Pw(S3). Therefore, in step S1006, the control unit 100 causes the imaging unit 8A to capture an image of the imaging range Ri and obtain an image including the imaging point Pw(S3). This allows the control unit 100 to obtain an image indicating the position of the unprocessed planned division line S3.

[0143] Next, the speed change of the laser irradiation position Lb will be described with reference to "speed change in X direction" and "speed change in Y direction" in Fig. 15C. In a line processing period Ts1 (steps S1002 to S1004) in which a line processing process is performed to move the laser light B to the (+X) side along the division line S1, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction. In addition, in a line processing period Ts2 (steps S1002 to S1004) in which a line processing process is performed to move the laser light B to the (-X) side along the division line S2, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction.

[0144] Also, in a switching period Tc (steps S1005, S1006, S1001) in which the line processing period Ts1 is switched to the line processing period Ts2, the laser irradiation position Lb is moved in the Y direction (feed direction) from the virtual straight line Sv1 to the virtual straight line Sv2 in parallel with the inversion drive in the X direction as described above. In particular, this movement of the laser irradiation position Lb is executed via the position Pb2. That is, of the deceleration period Td and the acceleration period Ta included in the switching period Tc, the laser irradiation position Lb moves in the Y direction from the virtual straight line Sv1 to the position Pb2 in the deceleration period Td, and the laser irradiation position Lb moves in the Y direction from the position Pb2 to the virtual straight line Sv2 in the acceleration period Ta. Specifically, the laser irradiation position Lb starts moving from the virtual straight line Sv1 to the position Pb2 at the same time as the deceleration period Td starts, and the laser irradiation position Lb reaches the position Pb2 at the same time as the deceleration period Td ends. Moreover, the laser irradiation position Lb starts moving from the position Pb2 to the imaginary line Sv2 at the same time as the acceleration period Ta starts, and the laser irradiation position Lb reaches the imaginary line Sv2 at the same time as the acceleration period Ta ends.

[0145] During a stop period Tt provided during the transition from the acceleration period Ta to the deceleration period Td, both the velocity Vx in the X direction and the velocity Vy in the Y direction of the laser irradiation position Lb become zero, and the laser irradiation position Lb stops at position Pb2 relative to the semiconductor substrate W. During this stop period Tt, the imaging range Ri of the imaging units 8A and 8B also stops relative to the semiconductor substrate W, and in particular, the imaging range Ri of the imaging unit 8B is located on the (-X) side of the laser irradiation position Lb located on the (+X) side of the semiconductor substrate W, overlapping with the semiconductor substrate W. Therefore, during the stop period Tt, the infrared camera 81 of the imaging unit 8B images a portion of the semiconductor substrate W that overlaps with the imaging range Ri (step S1006).

[0146] In addition, during the switching period Tc, the specific manner in which the image sensor 1 moves in the Y direction from the virtual straight line Sv1 to the position Pb2 and then moves in the Y direction from the position Pb2 to the virtual straight line Sv2 is not limited to the example of FIG. 15C, and this movement may be performed in the manner shown in, for example, FIG. 15D, FIG. 15E, and FIG. 15F.

[0147] Fig. 15D is a diagram showing a fourth example of the operation performed according to the flowchart of Fig. 14, Fig. 15E is a diagram showing a fifth example of the operation performed according to the flowchart of Fig. 14, and Fig. 15F is a diagram showing a sixth example of the operation performed according to the flowchart of Fig. 14. The notations in Fig. 15D to Fig. 15F are the same as those in Fig. 15C. The difference between Fig. 15D to Fig. 15F and Fig. 15C is the movement mode of the laser irradiation position Lb during the switching period Tc. Therefore, the difference with Fig. 15C will be mainly described, and the common operations will be denoted by corresponding symbols and appropriately omitted from description.

[0148] In the fourth example shown in FIG. 15D, the laser irradiation position Lb starts moving in the Y direction from the virtual straight line Sv1 to the position Pb2 at the same time as the deceleration period Td starts, and before the deceleration period Td ends, the laser irradiation position Lb reaches the position Pb2 in the Y direction and stops at the position Pb2 (i.e., the speed Vy is zero). However, after the laser irradiation position Lb reaches the position Pb2 in the Y direction, the deceleration period Td continues, and the laser irradiation position Lb continues moving in the X direction. In addition, after the acceleration period Ta starts, the laser irradiation position Lb starts moving in the Y direction from the position Pb2 to the virtual straight line Sv2, and at the same time as the acceleration period Ta ends, the laser irradiation position Lb reaches the virtual straight line Sv2. In other words, during the period ΔTy from the middle of the deceleration period Td to the middle of the acceleration period Ta, the laser irradiation position Lb stops in the Y direction (i.e., the speed Vy is zero).

[0149] In the fifth example shown in FIG. 15E, the laser irradiation position Lb starts moving in the Y direction from the virtual straight line Sv1 to the position Pb2 at the same time as the deceleration period Td starts, and before the deceleration period Td ends, the laser irradiation position Lb reaches the position Pb2 in the Y direction and stops at the position Pb2 (i.e., the speed Vy is zero). However, after the laser irradiation position Lb reaches the position Pb2 in the Y direction, the deceleration period Td continues, and the laser irradiation position Lb continues moving in the X direction. Also, the laser irradiation position Lb starts moving in the Y direction from the position Pb2 to the virtual straight line Sv2 at the same time as the acceleration period Ta starts, and the laser irradiation position Lb reaches the virtual straight line Sv2 at the same time as the acceleration period Ta ends. That is, during the period ΔTy from the middle of the deceleration period Td to the start of the acceleration period Ta, the laser irradiation position Lb stops in the Y direction (i.e., the speed Vy is zero).

[0150] In the fifth example shown in FIG. 15F, the laser irradiation position Lb starts moving in the Y direction from the virtual straight line Sv1 to the position Pb2 at the same time as the deceleration period Td starts. However, at the end of the deceleration period Td, the laser irradiation position Lb does not reach the position Pb2 in the Y direction. At the end of the deceleration period Td, the position (i.e., X coordinate) of the laser irradiation position Lb and the position (i.e., X coordinate) of the position Pb2 in the X direction coincide with each other. Therefore, the laser irradiation position Lb continues to move in the Y direction toward the position Pb2 even after the end of the deceleration period Td. Also, during the period from the end of the deceleration period Td to the time when the laser irradiation position Lb moves in the Y direction toward the position Pb2, the laser irradiation position Lb stops in the X direction (i.e., the speed Vx is zero). Then, at the same time when the laser irradiation position Lb reaches the position Pb2, the acceleration period Ta starts and the laser irradiation position Lb starts moving in the Y direction from the position Pb2 to the virtual straight line Sv2. Moreover, at the same time that the acceleration period Ta ends, the laser irradiation position Lb reaches the imaginary line Sv2.

[0151] FIG. 15G is a diagram showing a seventh example of the operation performed according to the flowchart of FIG. 14. The notation in FIG. 15G is the same as that in FIG. 15A. In FIG. 15G, the laser processing is performed in order on the division lines S1, S2, and S3 according to the flowchart of FIG. 14, as in FIG. 15A. However, the operation in the switching period Tc for changing the division line S to be subjected to the laser processing is different between FIG. 15G and FIG. 15A. Therefore, the difference from FIG. 15A will be mainly described, and the common operations will be denoted by corresponding symbols and appropriately omitted from description.

[0152] When the laser irradiation position Lb passes the dividing line S1 on the (+X) side with the end of the laser processing on the dividing line S1, the laser irradiation position Lb starts to decelerate toward the (+X) side in the X direction (step S1005), and the laser irradiation position Lb stops at a position Pb2 on the (+X) side of the semiconductor substrate W in the X direction (step S1006). This position Pb2 is provided outside the section between the virtual straight lines Sv1 and Sv2 in the Y direction (the opposite side of the virtual straight line Sv1 with respect to the virtual straight line Sv2). That is, in steps S1005 to S1006, the laser irradiation position Lb moves in the Y direction from the virtual straight line Sv1 to the position Pb2 beyond the virtual straight line Sv2 in parallel with the deceleration in the X direction. In addition, when the laser irradiation position Lb stops at the position Pb2, the imaging range Ri of the imaging unit 8B stops at a position including at least the imaging point Pw (S3). Therefore, in step S1006, the control unit 100 causes the imaging unit 8B to capture an image of the imaging range Ri to obtain an image including the imaging point Pw(S3). This allows the control unit 100 to obtain an image indicating the position of the unprocessed planned division line S3.

[0153] Next, the laser irradiation position Lb, which stops at the position Pb2, starts accelerating toward the (-X) side in the X direction (step S1001). Then, when the speed Vx of the laser irradiation position Lb increases to the processing speed Vxd before the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser irradiation position Lb moves at a constant speed toward the (-X) side in the X direction at the processing speed Vxd (step S1002). In addition, during the period from when the laser irradiation position Lb starts accelerating to when it starts moving at a constant speed at the processing speed Vxd, the laser irradiation position Lb moves in the Y direction from the position Pb2 to the virtual straight line Sv2. That is, in steps S1001 to S1002, the laser irradiation position Lb moves in the Y direction from the position Pb2 to the virtual straight line Sv2 in parallel with the acceleration in the X direction. As a result, the laser irradiation position Lb reaches the planned division line S2, and line processing on the planned division line S2 can be started.

[0154] When the laser irradiation position Lb passes the dividing line S2 on the (-X) side with the end of the laser processing on the dividing line S2, the laser irradiation position Lb starts to decelerate toward the (-X) side in the X direction (step S1005), and the laser irradiation position Lb stops at a position Pb3 on the (-X) side of the semiconductor substrate W in the X direction (step S1006). This position Pb3 is provided outside the section between the virtual straight lines Sv2 and Sv3 in the Y direction (the opposite side of the virtual straight line Sv2 with respect to the virtual straight line Sv3). That is, in steps S1005 to S1006, the laser irradiation position Lb moves in the Y direction from the virtual straight line Sv2 to the position Pb2 beyond the virtual straight line Sv3 in parallel with the deceleration in the X direction. In addition, when the laser irradiation position Lb stops at the position Pb3, the imaging range Ri of the imaging unit 8A stops at a position including at least the imaging point Pw (S4). Therefore, in step S1006, the control unit 100 causes the imaging unit 8A to capture an image of the imaging range Ri and obtain an image including the imaging point Pw(S4). This allows the control unit 100 to obtain an image indicating the position of the unprocessed planned division line S4.

[0155] Next, the speed change of the laser irradiation position Lb will be described with reference to "Speed ​​change in X direction" and "Speed ​​change in Y direction" in Fig. 15G. In a line processing period Ts1 (steps S1002 to S1004) in which a line processing process is performed to move the laser light B to the (+X) side along the division line S1, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction. In addition, in a line processing period Ts2 (steps S1002 to S1004) in which a line processing process is performed to move the laser light B to the (-X) side along the division line S2, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction.

[0156] Also, in a switching period Tc (steps S1005, S1006, S1001) in which the line processing period Ts1 is switched to the line processing period Ts2, the laser irradiation position Lb is moved in the Y direction (feed direction) from the virtual straight line Sv1 to the virtual straight line Sv2 in parallel with the inversion drive in the X direction as described above. In particular, this movement of the laser irradiation position Lb is executed via a position Pb2 provided outside the section between the virtual straight lines Sv1 and Sv2 in the Y direction. That is, of the deceleration period Td and the acceleration period Ta included in the switching period Tc, the laser irradiation position Lb moves in the Y direction from the virtual straight line Sv1 to the position Pb2 beyond the virtual straight line Sv2 during the deceleration period Td, and the laser irradiation position Lb moves in the Y direction from the position Pb2 to the virtual straight line Sv2 during the acceleration period Ta. Specifically, the laser irradiation position Lb starts moving from the virtual line Sv1 to the position Pb2 at the same time as the deceleration period Td starts, and reaches the position Pb2 at the same time as the deceleration period Td ends. Also, the laser irradiation position Lb starts moving from the position Pb2 to the virtual line Sv2 at the same time as the acceleration period Ta starts, and reaches the virtual line Sv2 at the same time as the acceleration period Ta ends.

[0157] During a stop period Tt provided during the transition from the acceleration period Ta to the deceleration period Td, both the velocity Vx in the X direction and the velocity Vy in the Y direction of the laser irradiation position Lb become zero, and the laser irradiation position Lb stops at position Pb2 relative to the semiconductor substrate W. During this stop period Tt, the imaging range Ri of the imaging units 8A and 8B also stops relative to the semiconductor substrate W, and in particular, the imaging range Ri of the imaging unit 8B is located on the (-X) side of the laser irradiation position Lb located on the (+X) side of the semiconductor substrate W, overlapping with the semiconductor substrate W. Therefore, during the stop period Tt, the infrared camera 81 of the imaging unit 8B images a portion of the semiconductor substrate W that overlaps with the imaging range Ri (step S1006).

[0158] In the above example, the position Pb2 is provided on the opposite side of the virtual line Sv1 with respect to the virtual line Sv2 in the Y direction. However, the position Pb2 may be provided on the opposite side of the virtual line Sv2 with respect to the virtual line Sv1 in the Y direction. In this case, during the deceleration period Td, the laser irradiation position Lb moves in the Y direction from the virtual line Sv1 to the position Pb2, and during the acceleration period Ta, the laser irradiation position Lb moves in the Y direction from the position Pb2 to the virtual line Sv2 beyond the virtual line Sv1. A similar change is possible for the position Pb3.

[0159] FIG. 16 is a flow chart showing a first application example of the line processing process for each division planned line, and FIG. 17 is a diagram showing an example of the operation executed according to the flow chart of FIG. 16. The notation in FIG. 17 is the same as that in FIG. 15A to FIG. 15G. The example of FIG. 16 and the example of FIG. 14 differ in the presence or absence of step S1008 for imaging the semiconductor substrate W during the line processing process, but are common in other steps S1001 to S1007. Therefore, in the example of FIG. 16, any of the operations (first to seventh examples) shown in FIG. 15A to FIG. 15G is executed. Note that FIG. 17 does not show the trajectory of the laser irradiation position Lb during the switching period Tc, but the laser irradiation position Lb can move along any of the trajectories shown in FIG. 15A to FIG. 15G.

[0160] Step S1008 in FIG. 16 is executed as follows. That is, the semiconductor substrate W is imaged while the laser irradiation position Lb is moving along the planned division line S1 (step S1008). Specifically, an image is captured of the imaging range Ri (i.e., the imaging range Ri of the imaging unit 8A) located on the moving side of the laser irradiation position Lb (i.e., the (+X) side) of the laser irradiation position Lb moving to the (+X) side. This allows an image to be acquired that includes an imaging point Pw (S11) on the moving side of the laser irradiation position Lb than the laser irradiation position Lb. In this way, an image showing the position of the unprocessed portion of the planned division line S1 during the line processing process can be acquired.

[0161] That is, during the execution periods of steps S1003, S1108, and S1104, while the line processing process is being executed on the planned division line S1, an image of the unprocessed portion of the planned division line S1 that is the target of the line processing process is captured.

[0162] Moreover, the semiconductor substrate W is imaged while the laser irradiation position Lb is moving along the planned division line S2 (step S1008). Specifically, an image is captured of the imaging range Ri (i.e., the imaging range Ri of the imaging unit 8B) located on the moving side of the laser irradiation position Lb (i.e., the (-X) side) of the laser irradiation position Lb moving to the (-X) side. This allows an image to be acquired that includes an imaging point Pw (S21) on the moving side of the laser irradiation position Lb. In this way, an image showing the position of the unprocessed portion of the planned division line S2 during the line processing process can be acquired.

[0163] That is, during the execution periods of steps S1003, S1108, and S1104, the line processing is executed on the planned division line S2, and in parallel therewith, an image of an unprocessed portion of the planned division line S2 that is the target of the line processing is captured.

[0164] Furthermore, the semiconductor substrate W is imaged while the laser irradiation position Lb is moving along the planned division line S3 (step S1008). Specifically, an image is captured of the imaging range Ri (i.e., the imaging range Ri of the imaging unit 8A) located on the moving side of the laser irradiation position Lb (i.e., the (+X) side) of the laser irradiation position Lb moving to the (+X) side. This allows an image to be acquired that includes an imaging point Pw (S31) on the moving side of the laser irradiation position Lb. In this way, an image showing the position of the unprocessed portion of the planned division line S3 during the line processing process can be acquired.

[0165] That is, during the execution periods of steps S1003, S1108, and S1104, the line processing is executed on the planned division line S3, and in parallel therewith, an image of an unprocessed portion of the planned division line S3 that is the target of the line processing is captured.

[0166] Then, steps S1001 to S1007 are repeated until it is confirmed that the laser processing is completed for a plurality of planned division lines S (S1, S2, S3, . . . ) parallel to the X direction ("YES" in step S1007).

[0167] Fig. 18 is a flow chart showing a second application example of the line processing process for each division line, and Fig. 19A is a diagram showing a first example of the operation executed according to the flow chart of Fig. 18. In Fig. 19A, the locus of the laser irradiation position Lb that moves relatively to the semiconductor substrate W is shown by a dotted line, and virtual straight lines Sv1, Sv2, and Sv3 extending parallel to the X direction between both outer sides of the division lines S1, S2, and S3 along the division lines S1, S2, and S3 are shown by a dashed line. Note that in the part where the locus of the laser irradiation position Lb and the virtual straight lines Sv1, Sv2, and Sv3 overlap, the dotted line showing the locus of the laser irradiation position Lb is preferentially shown.

[0168] In the example shown in Fig. 19A, the flow chart of Fig. 18 starts from a state in which the laser irradiation position Lb is stopped at a position Pb1 on the (-X) side of the semiconductor substrate W in the X direction. This position Pb1 is provided on a virtual straight line Sv1 along the planned division line S1, in other words, a position facing the planned division line S1 from the X direction. However, the position of the laser irradiation position Lb when starting the flow chart of Fig. 18 is not limited to this example and can be changed as appropriate.

[0169] In step S1101, the laser irradiation position Lb stopped at position Pb1 starts accelerating toward the (+X) side in the X direction and moves parallel to the X direction. This causes the laser irradiation position Lb to move toward the (+X) side along the virtual straight line Sv1. Then, when the speed Vx of the laser irradiation position Lb increases to the processing speed Vxd before the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (-X) side, the laser irradiation position Lb moves at a constant speed toward the (+X) side in the X direction at the processing speed Vxd (step S1102).

[0170] Furthermore, in synchronization with the timing at which the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (-X) side, the laser light source 72 is turned on, and irradiation of the laser light B from the processing head 71 to the laser irradiation position Lb is started (step S1103). As a result, the laser light B is irradiated to the laser irradiation position Lb moving along the planned division line S1 to the (+X) side in the X direction, and the planned division line S1 is processed (line processing process).

[0171] Also, in this example, the semiconductor substrate W is imaged while the laser irradiation position Lb is moving along the planned division line S1 (step S1104). Specifically, an image is captured of the imaging range Ri (i.e., the imaging range Ri of the imaging unit 8A) located on the moving side of the laser irradiation position Lb (i.e., the (+X) side) of the laser irradiation position Lb moving to the (+X) side. This allows an image to be acquired that includes an imaging point Pw (S11) on the moving side of the laser irradiation position Lb. In this way, an image showing the position of the unprocessed portion of the planned division line S1 during the line processing process can be acquired.

[0172] Then, in synchronization with the timing at which the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser light source 72 is turned off, and irradiation of the laser light B from the processing head 71 to the laser irradiation position Lb ends (step S1105). Thus, during the period from steps S1103 to S1105, an image of an unprocessed portion of the planned division line S1 that is the target of the line processing is captured in parallel with the line processing being executed on the planned division line S1.

[0173] When the laser irradiation position Lb passes the planned division line S1 on the (+X) side, the laser irradiation position Lb starts to decelerate toward the (+X) side in the X direction (step S1106). In step S1107, it is confirmed whether laser processing has been completed for multiple planned division lines S parallel to the X direction. Then, if there is an unprocessed planned division line S among these planned division lines S (if "NO" in step S1107), the process returns to step S1101.

[0174] As a result, the speed Vx of the laser irradiation position Lb in the X direction, which has been decelerated toward the (+X) side in the X direction, becomes zero, and then the laser irradiation position Lb accelerates toward the (-X) side in the X direction (step S1101). Then, when the speed Vx of the laser irradiation position Lb increases to the processing speed Vxd before the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser irradiation position Lb moves at a constant speed toward the (-X) side in the X direction at the processing speed Vxd (step S1102).

[0175] 18 and 19A, the inversion drive is executed in the X direction in the same manner as described above. In parallel with this inversion drive, the laser irradiation position Lb moves in the Y direction from the virtual straight line Sv1 to the virtual straight line Sv2. As a result, the laser irradiation position Lb moves in the Y direction to the virtual straight line Sv2 before the speed Vx of the laser irradiation position Lb in the X direction increases to the processing speed Vxd, and the laser irradiation position Lb reaches the planned division line S2.

[0176] However, in this example, the manner in which the laser irradiation position Lb moves in the Y direction is different from that described above. That is, in parallel with the reverse drive in which the laser irradiation position Lb decelerates, stops, and accelerates in the X direction, the laser irradiation position Lb continuously moves in the Y direction from the division line Sb1 to the division line Sb2 (continuous feed drive). In particular, the continuous feed drive of the laser irradiation position Lb in the Y direction is executed around the time when the speed Vx of the laser irradiation position Lb in the X direction becomes zero due to the reverse drive. Therefore, in this example, there is no timing when both the speed Vx in the X direction and the speed Vy in the Y direction of the laser irradiation position Lb become zero.

[0177] At the same time that the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser light source 72 is turned on and the processing head 71 starts irradiating the laser light B to the laser irradiation position Lb (step S1103). As a result, the laser light B is irradiated to the laser irradiation position Lb moving along the planned division line S2 to the (-X) side in the X direction, and the planned division line S2 is processed (line processing process).

[0178] Also, in this example, the semiconductor substrate W is imaged while the laser irradiation position Lb is moving along the planned division line S2 (step S1104). Specifically, an image is captured of the imaging range Ri (i.e., the imaging range Ri of the imaging unit 8B) located on the moving side of the laser irradiation position Lb (i.e., the (-X) side) of the laser irradiation position Lb moving to the (-X) side. This allows an image to be acquired that includes an imaging point Pw (S21) on the moving side of the laser irradiation position Lb. In this way, an image showing the position of the unprocessed portion of the planned division line S2 during the line processing process can be acquired.

[0179] Then, in synchronization with the timing at which the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (-X) side, the laser light source 72 is turned off, and irradiation of the laser light B from the processing head 71 to the laser irradiation position Lb ends (step S1105). Thus, during the period from steps S1103 to S1105, an image of an unprocessed portion of the planned division line S2 that is the target of the line processing is captured in parallel with the line processing being executed on the planned division line S2.

[0180] When the laser irradiation position Lb passes the planned division line S2 on the (-X) side, the laser irradiation position Lb starts to decelerate toward the (-X) side in the X direction (step S1106). In step S1107, it is confirmed whether laser processing has been completed for multiple planned division lines S parallel to the X direction. Then, if there is an unprocessed planned division line S among these planned division lines S (if "NO" in step S1107), the process returns to step S1101.

[0181] As a result, the speed Vx of the laser irradiation position Lb in the X direction, which has been decelerated toward the (-X) side in the X direction, becomes zero, and then the laser irradiation position Lb accelerates toward the (+X) side in the X direction (step S1101). Then, when the speed Vx of the laser irradiation position Lb increases to the processing speed Vxd before the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (-X) side, the laser irradiation position Lb moves at a constant speed toward the (+X) side in the X direction at the processing speed Vxd (step S1102).

[0182] At this time, similarly to the above, continuous feed drive in the Y direction is executed on the laser irradiation position Lb in parallel with the reversal drive in the X direction. As a result, by the time the speed Vx of the laser irradiation position Lb in the X direction increases to the processing speed Vxd, the laser irradiation position Lb moves to the virtual straight line Sv3 in the Y direction and reaches the planned division line S3.

[0183] At the same time that the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (-X) side, the laser light source 72 is turned on and the processing head 71 starts irradiating the laser light B to the laser irradiation position Lb (step S1103). As a result, the laser light B is irradiated to the laser irradiation position Lb moving along the planned division line S3 to the (+X) side in the X direction, and the planned division line S3 is processed (line processing process).

[0184] Also, in this example, the semiconductor substrate W is imaged while the laser irradiation position Lb is moving along the planned division line S3 (step S1104). Specifically, an image is captured of the imaging range Ri (i.e., the imaging range Ri of the imaging unit 8A) located on the moving side of the laser irradiation position Lb (i.e., the (+X) side) of the laser irradiation position Lb moving to the (+X) side. This allows an image to be acquired that includes an imaging point Pw (S31) on the moving side of the laser irradiation position Lb. In this way, an image showing the position of the unprocessed portion of the planned division line S3 during the line processing process can be acquired.

[0185] Then, in synchronization with the timing at which the laser irradiation position Lb reaches the end of the semiconductor substrate W on the (+X) side, the laser light source 72 is turned off, and irradiation of the laser light B from the processing head 71 to the laser irradiation position Lb ends (step S1105). Thus, during the period from steps S1103 to S1105, an image of an unprocessed portion of the planned division line S3 that is the target of the line processing is captured in parallel with the line processing being executed on the planned division line S3.

[0186] Next, the speed change of the laser irradiation position Lb will be described with reference to "speed change in X direction" and "speed change in Y direction" in Fig. 19A. In a line processing period Ts1 (steps S1103 to S1105) in which a line processing process is performed to move the laser light B to the (+X) side along the division line S1, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction. In addition, in a line processing period Ts2 (steps S1103 to S1105) in which a line processing process is performed to move the laser light B to the (-X) side along the division line S2, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd but does not move in the Y direction.

[0187] In addition, during a switching period Tc (steps S1106, S1101) when the line processing period Ts1 is switched to the line processing period Ts2, the following operation is executed. That is, the X-axis drive unit 65 (processing axis drive unit) decelerates the laser irradiation position Lb that has passed the planned division line S1 (first processing line) toward the (+X) side (first side) in the X direction (processing direction) toward the (+X) side, stops it (step S1106), and then accelerates it toward the (-X) side (step S1101), thereby executing a reversal drive to bring the laser irradiation position Lb to the planned division line S2 (second processing line). In parallel with this reversal drive, the Y-axis drive unit 63 (feed axis drive unit) executes a continuous feed drive that continuously moves the laser irradiation position Lb in the Y direction (feed direction) from a virtual straight line Sv1 (first virtual straight line) that extends in the X direction along the planned division line S1 to the outside of the planned division line S1 to a virtual straight line Sv2 (second virtual straight line) that extends in the X direction along the planned division line S2 to the outside of the planned division line S2.

[0188] In particular, the control unit 100 controls the X-axis drive unit 65 and the Y-axis drive unit 63 so that the Y-axis drive unit 63 starts the continuous feed drive before the X-axis drive unit 65 stops the laser irradiation position Lb in the X direction by the reversal drive, and the Y-axis drive unit 63 ends the continuous feed drive after the X-axis drive unit 65 stops the laser irradiation position Lb in the X direction by the reversal drive. In this way, the Y-axis drive unit 63 moves the laser irradiation position Lb in the Y direction before and after the movement of the laser irradiation position Lb in the X direction stops due to the reversal drive (in other words, during the period when the X-axis drive unit 65 stops the laser irradiation position Lb in the X direction by the reversal drive).

[0189] In other words, the switching period Tc includes a deceleration period Td (step S1006) in which the laser irradiation position Lb is decelerated in the X direction, and an acceleration period Ta (step S1001) in which the laser irradiation position Lb is accelerated in the X direction. Meanwhile, the Y-axis driving unit 63 continuously moves the laser irradiation position Lb in the Y direction before and after a transition period Tx in which the deceleration period Td transitions to the acceleration period Ta (i.e., moves the laser irradiation position Lb in the Y direction without stopping it). During the transition period Tx, the laser irradiation position Lb is stopped in the X direction (i.e., the speed Vx is zero).

[0190] FIG. 19B is a diagram showing a second example of the operation executed according to the flowchart of FIG. 18. FIG. 19B differs from FIG. 19A in the number of times the semiconductor substrate W is imaged in parallel with the line processing. That is, in the example of FIG. 19B, in order to execute the line processing on the planned division line S1, the imaging of the imaging range Ri (i.e., the imaging range Ri of the imaging unit 8A) located on the moving side of the laser irradiation position Lb (i.e., the (+X) side) from the laser irradiation position Lb moving to the (+X) side is executed multiple times (in this example, twice) (step S1104). As a result, two images including two imaging points Pw(S11) and Pw(S12) on the moving side of the laser irradiation position Lb from the laser irradiation position Lb are acquired. In this way, an image showing the position of the unprocessed part of the planned division line S1 during the line processing can be acquired.

[0191] Similarly, in order to execute the line processing process on the planned division line S2, the imaging of the imaging range Ri (i.e., the imaging range Ri of the imaging unit 8B) located on the moving side of the laser irradiation position Lb (i.e., the (-X) side) from the laser irradiation position Lb moving to the (-X) side is executed multiple times (in this example, twice) (step S1104). As a result, two images including two imaging points Pw (S21) and Pw (S22) on the moving side of the laser irradiation position Lb from the laser irradiation position Lb are acquired. In this way, an image showing the position of the unprocessed part of the planned division line S2 during the line processing process can be acquired. Similarly, in the line processing process on the planned division line S3, imaging is executed multiple times (step S1104).

[0192] FIG. 20 is a diagram showing an example of an image of a semiconductor substrate acquired in step S1008 of FIG. 16 or step S1104 of FIG. 18. In the above example, an image IM is acquired by capturing an image of an area including an intersection of two mutually orthogonal planned division lines S. At this time, since the image IM is acquired while the imaging range Ri moves in the X direction relative to the semiconductor substrate W, the brightness is averaged in the X direction in the image IM. As a result, a high brightness area that is high in brightness and extends parallel to the X direction corresponding to the planned division lines S, and a low brightness area that is low in brightness compared to the high brightness area and extends parallel to the X direction corresponding to the semiconductor chip C, are displayed. In particular, in the Y direction, the high brightness area is sandwiched between two low brightness areas. Therefore, the control unit 100 can confirm the position of the planned division line S in the Y direction based on the high brightness area corresponding to the planned division line S.

[0193] In the embodiment described above with reference to Figs. 16 to 20, during the line processing (steps S1003 to S1004, S1103 to S1105) in which the laser irradiation position Lb is moved along the dividing lines S and the laser beam B is irradiated to the laser irradiation position Lb to process the dividing lines S, an image of the portion of the semiconductor substrate W overlapping with the imaging range Ri is acquired by imaging the imaging range Ri which moves relatively to the semiconductor substrate W (steps S1008, S1104). That is, the period during which the line processing is performed is effectively utilized for imaging the semiconductor substrate W. In this way, in the laser processing technique in which the laser beam B is irradiated to the dividing lines S to process the dividing lines S, it is possible to efficiently image the semiconductor substrate W.

[0194] Moreover, the imaging unit 8 captures an image of an imaging range Ri provided downstream in the direction in which the laser irradiation position Lb moves relative to the intended division line S during the line processing (steps S1003 to S1004, S1103 to S1105) (steps S1008, S1104). In this configuration, an image of the unprocessed side of the position being processed by the laser light B (i.e., the laser irradiation position Lb) can be obtained. Therefore, the control unit 100 can recognize the effect of processing by the laser light B on the unprocessed portion of the semiconductor substrate W based on the image.

[0195] 19B, the imaging unit 8 captures the image of the imaging range Ri multiple times (steps S1008, S1104) during one execution of the line processing (steps S1003 to S1004, S1103 to S1105). With this configuration, the execution period of the line processing can be effectively utilized to acquire multiple images of the semiconductor substrate W.

[0196] 18 and 19A to 19B, a line processing process (first line processing process) for processing the division line S1 (first processing line) and a line processing process (second line processing process) for processing the division line S2 (second processing line) are sequentially performed using an X-axis drive unit 65 for moving the laser irradiation position Lb in the X direction relative to the semiconductor substrate W, and a Y-axis drive unit 63 (feed axis drive unit) for moving the laser irradiation position Lb in the Y direction relative to the semiconductor substrate W. In addition, during a switching period Tc between the line processing process for the division line S1 and the line processing process for the division line S2, the X-axis drive unit 65 and the Y-axis drive unit 63 perform the following operations to move the laser irradiation position Lb that has passed the division line S1 toward the division line S2. That is, the X-axis driving unit 65 executes a reverse drive in the X direction to make the laser irradiation position Lb reach the planned division line S2 by decelerating and stopping the laser irradiation position Lb that has passed the planned division line S1 on the (+X) side toward the (+X) side, and then accelerating it toward the (-X) side. Also, the Y-axis driving unit 63 moves the laser irradiation position Lb in the Y direction from a virtual straight line Sv1 that is extended in the X direction along the planned division line S1 to the outside of the planned division line S1, to a virtual straight line Sv2 that is extended in the X direction along the planned division line S2 to the outside of the planned division line S2.

[0197] In particular, the Y-axis drive unit 63 executes continuous feed drive to continuously move the laser irradiation position Lb in the Y direction from on the virtual straight line Sv1 to on the virtual straight line Sv2 during the switching period Tc. Then, the control unit 100 controls the X-axis drive unit 65 and the Y-axis drive unit 63 so that the Y-axis drive unit 63 starts the continuous feed drive before the X-axis drive unit 65 stops the laser irradiation position Lb by the reverse drive, and the Y-axis drive unit 63 ends the continuous feed drive after the X-axis drive unit 65 stops the laser irradiation position Lb by the reverse drive. In other words, the Y-axis drive unit 63 moves the laser irradiation position Lb in the Y direction before and after the movement of the laser irradiation position Lb in the X direction stops due to the reverse drive (in other words, during the period when the X-axis drive unit 65 stops the laser irradiation position Lb by the reverse drive). In this way, during the switching period Tc, both the period during which the laser irradiation position Lb is decelerated toward the (+X) side in the X direction and the period during which the laser irradiation position Lb is accelerated toward the (-X) side in the X direction are effectively used for moving the laser irradiation position Lb in the Y direction. As a result, it is possible to suppress the influence of the switching period Tc for switching the moving direction of the laser light B on the time required to complete processing of the semiconductor substrate W. Moreover, as described above, since the execution period of the line processing is effectively used for imaging the semiconductor substrate W, it is possible to suppress the time required to switch the planned dividing line S to be the target of the line processing, and to efficiently image the semiconductor substrate W, and to quickly complete processing of the semiconductor substrate W.

[0198] Moreover, the imaging unit 8 captures an imaging range Ri including at least the planned division line S during execution of the line processing process (FIG. 20). In the image IM acquired by such imaging, a portion corresponding to the planned division line S appears extended in the X direction due to the contrast between the planned division line S and both sides of the planned division line S in the Y direction. Therefore, the control unit 100@ can accurately recognize the effect of the laser processing on the position of the planned division line S in the Y direction based on the position of that portion in the Y direction.

[0199] Fig. 21 is a flow chart showing an example of a method for determining laser processing conditions in line processing, Fig. 22A is a diagram showing parameters related to the determination of the laser processing conditions, Fig. 22B is a diagram showing the influence of the laser processing conditions over time, and Fig. 22C is a diagram showing an example of a table referred to in determining the laser processing conditions in Fig. 21. This table is stored in advance in the storage unit 190.

[0200] FIG. 22A shows an upper graph representing the relationship between the speed Vx at which the laser irradiation position Lb moves in the X direction and time in the line processing, and a lower graph representing the relationship between the speed Vx at which the laser irradiation position Lb moves in the X direction and the position of the laser irradiation position Lb in the X direction (i.e., the X coordinate).

[0201] As shown in the graph below, in order to execute line processing on the planned division line S, irradiation position scanning is executed in which the laser irradiation position Lb overlapping the planned division line S is irradiated with the laser light B while moving the laser irradiation position Lb in the X direction from the start point Xs on one side of the planned division line S to the end point Xe on the other side (opposite to the one side). That is, the irradiation position scanning irradiates the laser light B from the processing head 71 to the laser irradiation position Lb overlapping the planned division line S while moving the laser irradiation position Lb in the X direction from the start point Xs to the end point Xe by the X-axis drive unit 65. In this way, the above-mentioned line processing is executed in conjunction with the irradiation position scanning.

[0202] In this irradiation position scanning, a constant velocity section SC is set for the planned division line S. This constant velocity section SC is set to be located between the start point Xs and the end point Xe in the X direction and to include the planned division line S. In this example, both ends of the constant velocity section SC in the X direction coincide with both ends of the planned division line S, in other words, the constant velocity section SC coincides with the planned division line S. However, the setting manner of the constant velocity section SC is not limited to this example, and the constant velocity section SC may be set by adding an offset to the outside from both ends of the planned division line S. In this case, the constant velocity section SC becomes longer than the planned division line S. The length of the offset may be a predetermined constant value, or may be a value obtained by multiplying the length of the planned division line S by a predetermined magnification (for example, 1%). The length of such a constant velocity section SC is set according to the length of the planned division line S, and specifically, the longer the planned division line S, the longer the constant velocity section SC becomes (in other words, the shorter the planned division line S, the shorter the constant velocity section SC becomes).

[0203] In this irradiation position scanning, the laser irradiation position Lb moves in the X direction from a start point Xs on one side of the uniform speed section SC to an end point Xe on the other side of the uniform speed section SC. In addition, in an acceleration period Ta in which the laser irradiation position Lb moves from the start point Xs to one end Xss of the uniform speed section SC in the X direction, the laser irradiation position Lb accelerates in the X direction at an acceleration A, and the X-directional speed Vx of the laser irradiation position Lb increases from zero to a processing speed Vxd. In addition, in a uniform speed period Tsc (which coincides with the line processing period Ts in this example) in which the laser irradiation position Lb moves in the X direction from one end Xss of the uniform speed section SC to the other end Xse, the laser irradiation position Lb moves in the X direction at a constant processing speed Vxd. Furthermore, in the X direction, during a deceleration period Td in which the laser irradiation position Lb moves from the other end Xse of the constant velocity section SC to the end point Xe, the laser irradiation position Lb decelerates in the X direction at an acceleration A, and the X-direction speed Vx of the laser irradiation position Lb decreases from the processing speed Vxd to zero.

[0204] In this case, the acceleration period Ta is the period (Vxd / A) required for the speed Vx to increase from zero to the processing speed Vxd at the acceleration A, the constant speed period Tsc is the period (Lsc / Vxd) required to move the constant speed distance Lsc, which is the length of the constant speed section SC, at the processing speed Vxd, and the deceleration period Td is the period (Vxd / A) required for the speed Vx to decrease from the processing speed Vxd to zero at the acceleration A. Therefore, the scanning time t required to scan the irradiation position is t=2×Vxd / A+Lsc / Vxd Therefore, the relationship shown in FIG. 22B is established between the processing speed Vxd and the scanning time t. In other words, when the processing speed Vxd is Vxd_min (=(Lsc×A / 2) 1 / 2 ), the scanning time t is at its minimum. Therefore, by setting the processing speed Vxd according to the length of the constant speed section SC (constant speed distance Lsc), the line processing can be performed efficiently.

[0205] However, when the processing speed Vxd is changed, it is necessary to change the frequency of the laser light B emitted from the laser light source 72. Specifically, the faster the processing speed Vxd is, the higher the frequency of the laser light B needs to be. In contrast, the frequency of the laser light B can only be changed stepwise, not continuously. Therefore, the table of FIG. 22C is used. This table specifies the relationship between the constant speed distance Lsc (in this example, the length of the planned division line S), the processing speed Vxd, and the frequency fc of the laser light B. Specifically, when the constant speed distance Lsc is equal to or less than Lsc(1), the processing speed Vxd is set to Vxd(1), and the frequency of the laser light B is set to fc(1), and when the constant speed distance Lsc is greater than Lsc(1) and equal to or less than Lsc(2), the processing speed Vxd is set to Vxd(2), and the frequency of the laser light B is set to fc(2). These laser processing conditions are specified in the table.

[0206] That is, in the laser processing condition determination of Fig. 21, the length (constant speed distance Lsc) of the constant speed section SC set for the planned division line S to be the target of the line processing process is acquired (step S1201). Then, based on the constant speed distance Lsc acquired in step S1201 and the table of Fig. 22C, the processing speed Vxd is determined (step S1202), and the frequency fc of the laser light B is determined (step S1203). In this way, according to the laser processing conditions (processing speed Vxd and frequency fc) determined by Fig. 21, the irradiation position scanning is performed.

[0207] Incidentally, the irradiation position scanning is performed sequentially for a plurality of planned division lines S parallel to the X direction. In other words, a plurality of irradiation position scanning is performed for different planned division lines S. In contrast, the laser processing condition determination in Fig. 21 is performed for each of a plurality of irradiation position scanning, and each irradiation position scanning performs movement of the laser irradiation position Lb and irradiation of the laser light B according to the laser processing conditions determined for that irradiation position scanning.

[0208] In particular, when the semiconductor substrate W on which multiple planned division lines S parallel to the X direction are formed is circular as in the above example, the planned division lines S become shorter as they move away from the center of the circle in the Y direction, and the uniform speed distance Lsc set for the planned division lines S also becomes shorter. In other words, the uniform speed distance Lsc set in the irradiation position scanning differs depending on the position in the Y direction of the planned division lines S targeted by the irradiation position scanning. Therefore, it becomes appropriate to execute the laser processing condition determination for each of the irradiation position scannings executed in sequence for the multiple planned division lines S.

[0209] The laser processing condition determination can be performed at any timing before the start of the irradiation position scanning targeted by the laser processing condition determination. For example, before the start of a plurality of irradiation position scannings corresponding to a plurality of planned division lines S parallel to the X direction, the laser processing condition determination may be performed for all of the plurality of irradiation position scannings. Alternatively, when a next irradiation position scanning is performed following a first irradiation position scanning, the laser processing condition determination for the next irradiation position scanning may be performed during the execution of the first irradiation position scanning.

[0210] As shown in FIG. 22C, the adjustment of the machining speed Vxd is performed by selecting one from among a plurality of discrete machining speeds Vxd(1), Vxd(2), Vxd(3), and Vxd(4), and the adjustment of the oscillation frequency fc is performed by selecting one from among a plurality of discrete oscillation frequencies fc(1), Vxd(2), Vxd(3), and Vxd(4). That is, in the laser machining condition determination, the machining speed Vxd and the oscillation frequency fc are selected according to which of the plurality of (four) ranges shown in FIG. 22C the constant speed distance Lsc belongs to. In this case, when the machining speed Vxd and the oscillation frequency fc are adjusted by performing the laser machining condition determination for each of the plurality of irradiation position scans, if the range to which the constant speed distance Lsc belongs is the same between the two laser irradiation position scans that are continuously performed, the machining speed Vxd and the oscillation frequency fc are maintained. On the other hand, when the ranges to which the constant speed distance Lsc belongs differ between two successively executed laser irradiation position scans, the machining speed Vxd and the transmission frequency fc are changed (in other words, switched). That is, the adjustment of the machining speed Vxd includes maintaining the machining speed Vxd and changing (switching) the machining speed Vxd, and the adjustment of the transmission frequency fc includes maintaining the transmission frequency fc and changing (switching) the transmission frequency fc.

[0211] As described above, in the above embodiment, the laser processing apparatus 1 corresponds to an example of the “laser processing apparatus” of the present invention, the chuck stage 3 corresponds to an example of the “support member” of the present invention, the Y-axis drive unit 63 corresponds to an example of the “feed axis drive unit” of the present invention, the X-axis drive unit 65 corresponds to an example of the “processing axis drive unit” of the present invention, the processing head 71 corresponds to an example of the “processing head” of the present invention, the imaging unit 8 corresponds to an example of the “imaging unit” of the present invention, the control unit 100 corresponds to an example of the “control unit” of the present invention, the control unit 100 corresponds to an example of the “computer” of the present invention, the laser processing program 191 corresponds to an example of the “laser processing program” of the present invention, and the recording medium 192 corresponds to an example of the “recording medium” of the present invention. The laser light B corresponds to an example of the "laser light" of the present invention, the laser irradiation position Lb corresponds to an example of the "laser irradiation position" of the present invention, the imaging range Ri corresponds to an example of the "imaging range" of the present invention, the planned division line S corresponds to an example of the "processing line" of the present invention, the virtual straight line Sv corresponds to an example of the "virtual straight line" of the present invention, the switching period Tc corresponds to an example of the "switching period" of the present invention, the semiconductor substrate W corresponds to an example of the "object to be processed" of the present invention, the X direction corresponds to an example of the "processing direction" of the present invention, the Y direction corresponds to an example of the "feed direction" of the present invention, and the (+X) side and the (-X) side correspond to the "first side" and "second side" of the present invention or the "second side" and "first side" of the present invention.

[0212] 16 to 20, the detailed operation of imaging the imaging range Ri that moves in the X direction with the execution of the line processing process by the infrared camera 81 may be modified as follows. Fig. 23 is a plan view that shows a schematic representation of the positional relationship between the laser irradiation position and the imaging range in the detailed operation of imaging the imaging range, and Fig. 24 is a plan view that shows a schematic representation of the imaging target in the detailed operation of imaging the imaging range.

[0213] 23, in a plan view, the imaging units 8 (8A, 8B) and the processing head 71 are arranged in the X direction so that the center Ric of the imaging range Ri of the imaging unit 8 (8A, 8B) and the focal point of the laser light B irradiated by the processing head 71 (i.e., the laser irradiation position Lb) are aligned parallel to the X direction. Also, as described above, of the two imaging ranges Ri, the imaging range Ri downstream in the movement direction of the laser irradiation position Lb is imaged by the infrared camera 81.

[0214] That is, as shown in Fig. 24, the laser light B irradiated to the laser irradiation position Lb moves in a scanning direction Ds parallel to the X direction, and the imaging range Ri moves in the scanning direction Ds on the downstream side of the laser irradiation position Lb in the scanning direction Ds. Here, in the line S to be divided, the downstream side of the laser irradiation position Lb in the scanning direction Ds is an unprocessed portion S_d that has not been processed by irradiation with the laser light B, and the upstream side of the laser irradiation position Lb in the scanning direction Ds is a processed portion S_u that has been processed by irradiation with the laser light B. Therefore, the imaging range Ri downstream of the laser irradiation position Lb in the scanning direction Ds includes the unprocessed portion S_d of the line to be divided S, and the laser processing control calculation unit 120 (control unit) can acquire an image IM of the unprocessed portion S_d of the line to be divided S by imaging the imaging range Ri.

[0215] In particular, the laser processing control calculation unit 120 causes the infrared camera 81 to perform exposure (panning operation) throughout a period (intersection period) during which the planned division line S intersects the imaging range Ri downstream of the laser irradiation position Lb in the scanning direction Ds (in other words, the unprocessed portion S_d). Here, the planned division line S intersecting the imaging range Ri refers to a state in which the planned division line S overlaps the imaging range Ri while both ends of the planned division line S are located outside the imaging range Ri.

[0216] Fig. 25 is a flowchart showing an example of exposure control of the camera. The flowchart in Fig. 25 is executed by the laser processing control calculation unit 120 controlling the infrared camera 81 via the camera control units 122A and 122B, and is executed in parallel with the line processing process for the planned division line S. In step S1301, it is determined whether the planned division line S intersects with the imaging range Ri on the downstream side in the scanning direction Ds (suitably referred to as the "downstream imaging range Ri") of the two imaging ranges Ri of each of the two infrared cameras 81 (i.e., whether the unprocessed portion S_d of the planned division line S intersects with it).

[0217] Then, at the timing when the downstream imaging range Ri intersects with the planned division line S ("YES" in step S1301), the infrared camera 81 imaging the downstream imaging range Ri starts exposure (step S1302). In step S1303, it is determined whether the downstream imaging range Ri has moved out of the unprocessed portion S_d of the planned division line S, i.e., has stopped intersecting. Then, at the timing when the downstream imaging range Ri moves out of the unprocessed portion S_d of the planned division line S ("YES" in step S1303), the exposure of the infrared camera 81 imaging the imaging range Ri is ended (step S1304).

[0218] In this way, the imaging range Ri moving in the scanning direction Ds with the movement of the laser irradiation position Lb is imaged by the infrared camera 81. In particular, exposure of the infrared camera 81 imaging the imaging range Ri is continued throughout the crossing period (the period of steps S1301 to S303) during which the imaging range Ri crosses the planned division line S downstream of the laser irradiation position Lb in the scanning direction Ds. Therefore, an image IM (suitably referred to as a "panning image IM") in which light from the imaging range Ri is accumulated throughout the crossing period is acquired. Specifically, the infrared camera 81 acquires the panning image IM by accumulating light (infrared rays) detected by a built-in solid-state imaging element. Note that, in this example, the period during which exposure is continued corresponds to the crossing period, but the period during which exposure is continued may be, for example, a period including the crossing period and longer than the crossing period.

[0219] FIG. 26 is a diagram showing information that can be obtained from a panning image captured by a panning operation. In FIG. 26, the planned division line S, the panning image IM obtained by capturing the planned division line S by a panning operation, and information (determination) that can be obtained from the panning image IM are associated with each other and shown for three different alignment states 1 to 3. Also, in the same figure, the trajectory J of the laser irradiation position Lb that moves in the X direction relatively to the semiconductor substrate W (in other words, the trajectory J of the center Ric of the imaging range Ri) is shown by a broken line. In particular, in the image IM, an accumulated line image AI obtained by accumulating light from the planned division line S appears, and information is obtained based on this accumulated line image AI.

[0220] In the alignment state 1, the planned division line S is parallel to the X direction and coincides with the locus J. Therefore, in the panning image IM, the accumulated line image AI extends parallel to the X direction at the position Yj (Y coordinate) of the locus J in the Y direction, and has a narrow width (width in the Y direction) and high brightness. From such an accumulated line image AI, it can be determined that the position of the planned division line S is good.

[0221] In the alignment state 2, the planned division line S extends parallel to the X direction, but is shifted in the Y direction with respect to the locus J. Therefore, in the panning image IM, the accumulated line image AI extends in the X direction at a position Yd shifted from the position Yj of the locus J in the Y direction, and has a narrow width and high brightness. From such an accumulated line image AI, it can be determined that a positional shift of a shift amount (Yd-Yj) occurs in the Y direction between the planned division line S and the locus J.

[0222] In the alignment state 3, the division line S is inclined with respect to the X direction. Therefore, in the image IM, the accumulated line image AI has a wide width and low brightness. From such an accumulated line image AI, it can be determined that the division line S is inclined with respect to the locus J.

[0223] Based on this knowledge, the laser processing control calculation unit 120 performs a judgment on the panning image IM as shown in Fig. 27. Fig. 27 is a flowchart showing an example of an image judgment performed on the panning image, and Fig. 28 is a diagram showing a schematic of a mask used in the image judgment in Fig. 27.

[0224] In step S1401, a mask process is performed on the panning image IM. The mask M (FIG. 28) used in the mask process functions to hide the ends Me on both sides of the panning image IM in the Y direction and extract the center part Mc between these ends Me. The ends Me extend parallel to the X direction, and the center part Mc has a rectangular shape. In step S1402, a cumulative line image AI is extracted from the center part Mc of the panning image IM. Specifically, the cumulative line image AI can be extracted by binarizing each pixel value (brightness) of the cumulative line image AI using a predetermined threshold value. In addition, image processing such as closing and opening may be used in combination as appropriate.

[0225] In step S1403, it is determined whether the luminance of the accumulated line image AI (for example, the average or median of the luminance) is equal to or greater than the threshold luminance. If the luminance of the accumulated line image AI is equal to or greater than the threshold luminance (YES in step S1403), it can be estimated that the panning image IM corresponds to processing result 1 or 2 among alignment states 1 to 3 illustrated in FIG.

[0226] Therefore, in step S1404, it is determined whether or not a positional deviation occurs in the Y direction between the position Yj of the locus J and the accumulated line image AI. Specifically, if the distance in the Y direction between the position Yj of the locus J and the accumulated line image AI is less than the threshold distance, it is determined that no positional deviation occurs (NO), whereas if the distance is equal to or greater than the threshold distance, it is determined that a positional deviation occurs (YES). If no positional deviation occurs ("NO" in step S1404), it is determined to be good (step S1405), and the line processing on the semiconductor substrate W continues.

[0227] On the other hand, if a positional deviation has occurred (if "YES" in step S1404), the position of the planned division line S relative to the trajectory J of the laser irradiation position Lb is corrected (positional deviation correction) in the line processing executed after the line processing executed in parallel with capturing the panning image IM. Specifically, the planned division line S on which line processing is executed after the planned division line S captured in the panning image IM (captured planned division line S) and the position of the laser irradiation position Lb are corrected in the Y direction by the positional deviation amount in the Y direction (=Yd-Yj). With the positional deviation corrected in this way, line processing is started for the planned division line S. As a result, line processing for the planned division line S can be started by the laser irradiation position Lb that is in an appropriate position in the Y direction. Note that, if the positional deviation correction is not completed in time for the planned division line S on which line processing is executed next after the captured planned division line S, it may be performed for the planned division line S on which line processing is executed next after the planned division line S.

[0228] If the brightness of the accumulated line image AI is less than the threshold brightness in step S1403 (if "NO" in step S1403), it can be estimated that the panning image IM corresponds to alignment state 3 among alignment states 1 to 3 illustrated in FIG. 26. Therefore, in step S1407, it is determined whether the width of the accumulated line image AI in the Y direction is less than the lower limit width. If the width of the accumulated line image AI is less than the lower limit width (if "YES" in step S1407), it is considered that an abnormality different from each alignment state illustrated in FIG. 26 has occurred. Therefore, the laser processing control calculation unit 120 notifies the user of a warning via a display or a buzzer (step S1408).

[0229] On the other hand, if the width of the accumulated line image AI is equal to or larger than the lower limit width (if "NO" in step S1407), it is estimated that the planned division line S is inclined with respect to the locus J of the laser irradiation position Lb, as exemplified in alignment state 3. Therefore, in step S1409, it is determined whether the width of the accumulated line image AI in the Y direction is equal to or larger than the upper limit width (wider than the lower limit width). If the width of the accumulated line image AI is equal to or larger than the upper limit width (if "YES" in step S1409), the inclination of the laser irradiation line G is excessive, and the laser processing control calculation unit 120 notifies the user of the inclination error by a display or a buzzer (step S1410).

[0230] On the other hand, if the width of the accumulated line image AI is less than the upper limit width ("NO" in step S1409), two-point alignment is performed (step S1411). In this two-point alignment, the positions (X coordinate, Y coordinate) of two predetermined points on the semiconductor substrate W are calculated based on the results of capturing images of these two points by the infrared camera 81. Furthermore, an angular deviation of the semiconductor substrate W in the θ direction is calculated from the positions of these two points, and the rotation angle of the semiconductor substrate W in the θ direction is adjusted based on this angular deviation. As a result, the planned dividing line S of the semiconductor substrate W is adjusted to be parallel to the X direction.

[0231] In this manner, in the modified example shown above, the center Ric of the imaging range Ri of the imaging unit 8 and the focal point of the laser light B irradiated to the laser irradiation position Lb are aligned in the X direction. Therefore, the state immediately before irradiation with the laser light B can be accurately captured by the image IM of the imaging range Ri.

[0232] Furthermore, during execution of a line processing process for one of the multiple planned division lines S (target line), the imaging unit 8 acquires an image IM by capturing an image for the entire period (panning operation) in which the infrared camera 81 is kept exposed throughout the period in which the unprocessed portion S_d of the one planned division line S intersects with the imaging range Ri. In this configuration, information (accumulated line image AI) that accumulates the brightness of the image IM in the imaging range Ri in the X direction can be obtained.

[0233] However, in such a panning image, the accumulated brightness may reach the dynamics range of the infrared camera 81 (solid-state image sensor), causing the brightness of the image IM to become saturated. Therefore, the imaging unit 8 adjusts the illumination intensity irradiated from the imaging unit 8 to the imaging range Ri. Specifically, the exposure time Tc and illumination intensity Tc in the panning operation are set to satisfy the following relational expression, with respect to the exposure time T0 and illumination intensity L0 in still imaging in which the infrared camera 81 is kept stationary with respect to the semiconductor substrate W and images are captured by the infrared camera 81. Lc=T0×L0 / Tc The illumination intensity Tc is adjusted so as to satisfy the following condition: This makes it possible to prevent the luminance of the image IM from becoming saturated.

[0234] Moreover, the laser processing control calculation unit 120 judges whether the laser irradiation position Lb with respect to the planned division line S is appropriate or not based on the panning image IM acquired by the panning operation (capturing images during the entire period) (FIG. 27). In this configuration, it is possible to check whether the laser irradiation position Lb is appropriate or not based on the panning image IM.

[0235] Further, the laser processing control calculation unit 120 judges the suitability of the laser irradiation position Lb with respect to the planned division line S based on the center part Mc of the panning image IM excluding both ends Me in the Y direction (orthogonal direction). With this configuration, it is possible to confirm the suitability of the laser irradiation position Lb by excluding unnecessary information appearing at both ends Me in the Y direction of the panning image IM.

[0236] Furthermore, when the laser processing control calculation unit 120 confirms, based on the panning image IM, that the laser irradiation position Lb has shifted in the Y direction relative to one planned division line S (target line) ("YES" in step S1404), it acquires the amount of positional deviation (Yd-Yj) in the Y direction of the laser irradiation position Lb relative to one planned division line S, and corrects the laser irradiation position Lb when performing line processing after the line processing on one planned division line S, based on the amount of positional deviation (Yd-Ys) (step S1406). This allows the positional deviation of the laser irradiation position Lb to be corrected in the Y direction, making it possible to properly perform the line processing.

[0237] Furthermore, when the laser processing control calculation unit 120 checks the inclination of the trajectory J of the laser irradiation position Lb with respect to one planned division line S (target line) based on the panning image IM, it executes alignment to correct the inclination (step S1411). With this configuration, it is possible to properly execute the line processing process by correcting the inclination of the laser irradiation position Lb with respect to the planned division line S.

[0238] The present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described embodiment without departing from the spirit of the present invention. Specifically, the following modifications are possible.

[0239] In the above example, the imaging unit 8 captures an image of the intersection of two mutually perpendicular planned division lines S, but the imaging target of the imaging unit 8 is not limited to this and may be, for example, an alignment mark attached to the semiconductor chip C.

[0240] Further, the specific configuration for moving the laser irradiation position Lb relatively to the semiconductor substrate W is not limited to the above-mentioned XYθ driving table 6, but may be, for example, a driving mechanism for driving the processing head 71 in the X and Y directions.

[0241] Furthermore, the number of imaging units 8 is not limited to two, and may be, for example, one.

[0242] Also, the semiconductor chips C may be individually separated by the above-mentioned laser processing method (substrate processing in FIG. 11, etc.) (semiconductor chip manufacturing method). In this semiconductor chip manufacturing method, a line processing process is performed on the division lines S of the semiconductor substrate W by the above-mentioned laser processing method, and a modified layer is formed (laser processing step). Next, the tape E holding the semiconductor substrate W is stretched to expand the tape E, thereby separating each of the multiple semiconductor chips C (expanding step). [Explanation of symbols]

[0243] 1...Laser processing equipment 3...Chuck stage (support member) 63...Y-axis drive unit (feed axis drive unit) 65...X-axis drive unit (machining axis drive unit) 71...Processing head 72...Laser light source 8…Imaging unit 100...Control unit (computer) 191...Laser processing program 192...Recording media

Claims

1. A support member that supports a workpiece having a plurality of processing lines parallel to each other such that the processing lines are parallel to a predetermined processing direction; A processing head that irradiates a laser beam to a predetermined laser irradiation position; a processing axis driving unit that drives at least one of the support member and the processing head in the processing direction to move the laser irradiation position relative to the workpiece in the processing direction; a control unit that executes a line processing process in which the processing line is processed by irradiating a laser beam to the laser irradiation position by the processing head while moving the laser irradiation position along the processing line by the processing axis drive unit; an imaging unit that images a predetermined imaging range that moves relatively to the object together with the laser irradiation position as the laser irradiation position moves relatively to the object; Equipped with the imaging unit captures an image of the imaging range that moves relatively to the object during execution of the line processing, thereby acquiring an image of a portion of the object that overlaps with the imaging range; A laser processing apparatus in which the center of the imaging range of the imaging unit and the focal point of the laser light irradiated to the laser irradiation position are aligned in the processing direction.

2. The laser processing device according to claim 1 , wherein the imaging section images the imaging range provided downstream in a direction in which the laser irradiation position moves relative to the processing line during the line processing.

3. The laser processing apparatus according to claim 1 , wherein the imaging unit captures images of the imaging range a plurality of times during a period in which the line processing process is performed once.

4. A feed axis drive unit drives at least one of the support member and the processing head in a feed direction perpendicular to the processing direction to move the laser irradiation position relative to the workpiece in the feed direction, The feed axis drive unit moves the laser irradiation position in the feed direction relative to the workpiece, thereby changing the processing line to be the target of the line processing among the multiple processing lines, The control unit sequentially executes a first line processing process for processing a first processing line among the plurality of processing lines by the line processing process moving the laser irradiation position to a first side in the processing direction, and a second line processing process for processing a second processing line among the plurality of processing lines, the second processing line being different from the first processing line, by the line processing process moving the laser irradiation position to a second side opposite to the first side in the processing direction; During a switching period from the end of the first line processing process to the start of the second line processing process, the processing axis drive unit executes a reverse drive in the processing direction to decelerate and stop the laser irradiation position that has passed the first processing line to the first side toward the first side, and then accelerates toward the second side, thereby causing the laser irradiation position to reach the second processing line, and the feed axis drive unit executes a continuous feed drive to continuously move the laser irradiation position in the feed direction from a first virtual straight line that is extended in the processing direction along the first processing line to the outside of the first processing line, to a second virtual straight line that is extended in the processing direction along the second processing line to the outside of the second processing line, 4. The laser processing apparatus according to claim 1, wherein the control unit controls the processing axis drive unit and the feed axis drive unit so that the feed axis drive unit starts the continuous feed drive before the processing axis drive unit stops the laser irradiation position with the reversal drive, and the feed axis drive unit ends the continuous feed drive after the processing axis drive unit stops the laser irradiation position with the reversal drive, thereby causing the feed axis drive unit to move the laser irradiation position in the feed direction before and after the movement of the laser irradiation position in the processing direction stops due to the reversal drive.

5. The laser processing apparatus according to claim 1 , wherein the imaging section images the imaging range including at least the processing line during execution of the line processing process.

6. 6. The laser processing apparatus according to claim 1, wherein, during execution of the line processing process on one target line among the plurality of processing lines, the imaging unit acquires the image by capturing images for the entire period during which an unprocessed portion of the one target line that has not been processed by irradiating the laser light intersects with the imaging range, thereby continuing to expose the camera.

7. The exposure time Tc and the illumination intensity Tc in the entire period of imaging are expressed by the following relational expression with respect to the exposure time T0 and the illumination intensity L0 when the camera images the processing object that is stationary with respect to the camera. Lc=T0×L0 / Tc The laser processing apparatus according to claim 6, which satisfies the above.

8. The laser processing apparatus according to claim 6 or 7, wherein the control unit determines whether the laser irradiation position with respect to the processing line is appropriate based on the image acquired by the entire period imaging.

9. The laser processing apparatus according to claim 8 , wherein the control unit determines whether the laser irradiation position with respect to the processing line is appropriate based on a central portion of the image excluding both ends in a direction perpendicular to the processing direction.

10. The laser processing apparatus of claim 8 or 9, wherein when the control unit confirms based on the image that the laser irradiation position has shifted in an orthogonal direction perpendicular to the processing direction relative to the one target line, the control unit acquires the amount of positional shift of the laser irradiation position in the orthogonal direction relative to the one target line, and corrects the laser irradiation position in the orthogonal direction based on the amount of positional shift when performing the line processing process after the one target line.

11. The laser processing apparatus according to any one of claims 8 to 10, wherein the control unit, when confirming an inclination of a trajectory of the laser irradiation position relative to the one target line based on the image, performs alignment to correct the inclination.

12. A step of supporting a workpiece having a plurality of processing lines parallel to each other by a support member such that the processing lines are parallel to a predetermined processing direction; a step of executing a line processing process in which the processing line is processed by irradiating a laser beam to the laser irradiation position by the processing head while moving the laser irradiation position along the processing line by a processing axis driving unit that drives at least one of a processing head that irradiates a laser beam to a predetermined laser irradiation position and the support member in the processing direction, thereby moving the laser irradiation position relative to the workpiece in the processing direction; an imaging unit that images a predetermined imaging range that moves relatively to the workpiece integrally with the laser irradiation position as the laser irradiation position moves relatively to the workpiece as the laser irradiation position moves relative to the workpiece captures an image of the imaging range that moves relatively to the workpiece during execution of the line processing, thereby acquiring an image of a portion of the workpiece that overlaps with the imaging range; Equipped with A laser processing method in which the center of the imaging range of the imaging unit and the focal point of the laser light irradiated to the laser irradiation position are aligned in the processing direction.

13. A laser processing program that causes a computer to execute the laser processing method according to claim 12.

14. A recording medium for recording the laser processing program according to claim 13 in a computer-readable manner.

15. A step of processing a semiconductor substrate on which a plurality of semiconductor chips are arranged and separated by processing lines, by the laser processing method according to claim 12; a step of expanding a tape that adhesively holds the semiconductor substrate processed by the laser processing method to separate the plurality of semiconductor chips; A semiconductor chip manufacturing method comprising:

16. A step of processing a semiconductor substrate on which a plurality of semiconductor chips are arranged and separated by processing lines, by the laser processing method according to claim 12; a step of expanding a tape that adhesively holds the semiconductor substrate processed by the laser processing method to separate the plurality of semiconductor chips; Semiconductor chips manufactured by.

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