Method for processing a workpiece

Abstract

The present application provides a workpiece processing method for processing a plate-shaped workpiece having a rectangular front surface and back surface with high precision. The workpiece processing method is used when processing a plate-shaped workpiece having a first surface with a rectangular shape including four edges and a second surface with a rectangular shape located on the opposite side of the first surface using a chuck table having a holding surface and a processing unit for processing the workpiece held by the chuck table. The workpiece processing method includes the following steps: a step of acquiring the orientation of the edge in the XY plane parallel to the holding surface and four XY coordinates showing the positions of the four edges in the XY plane according to displacement information obtained by measuring the height of the region including the four edges of the workpiece while the second surface side of the workpiece is held on the holding surface of the chuck table; and a processing step of processing the workpiece according to the orientation of the edge and the four XY coordinates.

Description

Technical Field

[0001] This invention relates to a method for processing a workpiece that has a rectangular front and back side. Background Technology

[0002] Optical components, such as the substrate that forms the screen of a flat panel display, are manufactured by processing a workpiece, such as a glass plate that is transparent in the visible light region. When processing such a workpiece, processing devices such as laser processing apparatus that generates and utilizes a high-output laser beam, or cutting apparatus that mounts an annular cutting tool containing abrasive grains on the spindle are used (see, for example, Patent Document 1).

[0003] These processing devices typically extract patterns of components or the like from images obtained by photographing the workpiece with a camera, and then identify the location (processing predetermined line) to be processed on the workpiece. On the other hand, when processing a workpiece without a pattern, for example, the workpiece is positioned at a specific location on the chuck table of the processing device, thereby enabling processing at that specific location on the workpiece.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2006-93333

[0005] Furthermore, although the workpiece transport mechanism within the machining apparatus is configured to transport the workpiece with high precision relative to the chuck table, there are still many instances where the actual position of the transported workpiece deviates from the target position by less than 5 mm. Therefore, in the aforementioned method of positioning the workpiece at a predetermined position on the chuck table, it may not be possible to machine the workpiece with sufficiently high precision.

[0006] For example, when machining a workpiece with a circular front and back side, the position of the center of the circle can be determined based on the positions of three points on the outer periphery, thereby enabling high-precision machining. However, this method cannot be directly applied to machining workpieces with rectangular front and back sides. Summary of the Invention

[0007] Therefore, the object of the present invention is to provide a new method for processing workpieces, which can process plate-shaped workpieces having rectangular front and back sides with high precision.

[0008] According to one aspect of the present invention, a method for processing a workpiece is provided. The workpiece is a plate-shaped workpiece having a rectangular first surface including four sides and a rectangular second surface located on the opposite side of the first surface. The method for processing the workpiece is used when processing the workpiece using a chuck table having a holding surface and a processing unit that processes the workpiece held by the chuck table. The method for processing the workpiece includes the following steps: an acquisition step, based on displacement information obtained by measuring the height of the region containing the four sides of the workpiece while the second surface of the workpiece is held on the holding surface of the chuck table, acquiring the orientation of the sides in an XY plane parallel to the holding surface and four XY coordinates indicating the positions of the four sides in the XY plane; and a processing step, processing the workpiece according to the orientation of the sides and the four XY coordinates.

[0009] In one embodiment of the present invention described above, the acquisition step sometimes further includes the following steps: an orientation acquisition step, in which the chuck table is moved relative to a measuring device for measuring height, thereby measuring the height of a region containing one side of the workpiece at different positions in the Y direction and on two straight lines parallel to the X direction, and calculating the XY coordinates of two positions where the side intersects the two straight lines based on the obtained displacement information, thereby acquiring the orientation of the side; a first coordinate acquisition step, in which, after adjusting the orientation of the chuck table about a rotation axis perpendicular to the XY plane so that the orientation of the side acquired by the orientation acquisition step becomes parallel to the Y direction, the measuring device is moved relative to the chuck table, thereby acquiring the orientation of the workpiece by measuring the height of a region containing one side of the workpiece at different positions in the Y direction and on two straight lines parallel to the X direction; and a first coordinate acquisition step, in which the orientation of the chuck table about a rotation axis perpendicular to the XY plane is adjusted so that the orientation of the side acquired by the orientation acquisition step becomes parallel to the Y direction, and the measuring device is moved relative to the chuck table, thereby acquiring the orientation of the workpiece by measuring the height of a region containing one side of the workpiece at different positions in the Y direction and on two straight lines parallel to the X direction, and calculating the XY coordinates of two positions where the side intersects the two straight lines based on the obtained displacement information, thereby acquiring the orientation of the workpiece ... by measuring the height of a region containing one side of the workpiece by measuring the height of The height of the region containing the two opposing sides of the workpiece is measured on a straight line parallel to the X direction. Based on the obtained displacement information, two XY coordinates showing the two positions where the two opposing sides intersect the straight line are obtained. In the second coordinate acquisition step, after adjusting the orientation of the chuck table about the rotation axis so that the orientation of the side obtained by the orientation acquisition step becomes perpendicular to the Y direction, the measuring device is moved relative to the chuck table, thereby measuring the height of the region containing the other two opposing sides of the workpiece on a straight line parallel to the X direction. Based on the obtained displacement information, two XY coordinates showing the two positions where the other two opposing sides intersect the straight line are obtained.

[0010] Additionally, in one embodiment of the present invention described above, the acquisition step sometimes further includes the following steps: a first coordinate acquisition step, in which the chuck table is moved relative to a measuring device for measuring height, thereby measuring the height of the region containing the two opposing sides of the workpiece at different positions in the Y direction and on two straight lines parallel to the X direction, and acquiring three or more XY coordinates showing three or more positions where the two opposing sides intersect the two straight lines based on the obtained displacement information; a second coordinate acquisition step, in which the measuring device is moved relative to the chuck table with the orientation of the chuck table about a rotation axis perpendicular to the XY plane perpendicular to the orientation of the chuck table in the first coordinate acquisition step, thereby measuring the height of the region containing the two opposing sides and on two straight lines parallel to the X direction. The height of the region containing the other two opposite sides of the workpiece is obtained based on the displacement information, showing two XY coordinates at two positions where the other two opposite sides intersect with the straight line; the orientation acquisition step obtains the orientation of one of the two opposite sides based on the two XY coordinates obtained through the first coordinate acquisition step showing two positions where one of the two opposite sides intersects with the two straight lines; and the coordinate correction acquisition step corrects the two XY coordinates obtained through the first coordinate acquisition step showing two positions where the two opposite sides intersect with the two straight lines and the two XY coordinates obtained through the second coordinate acquisition step based on the orientation of the side obtained through the orientation acquisition step, and obtains four corrected XY coordinates.

[0011] According to another aspect of the present invention, a method for processing a workpiece is provided. The workpiece is a plate-shaped workpiece having a rectangular first surface including four sides and a rectangular second surface located on the opposite side of the first surface. The method for processing the workpiece is used when processing the workpiece using a chuck table with a holding surface and a processing unit that processes the workpiece held by the chuck table. The method for processing the workpiece includes the following steps: an acquisition step, which involves acquiring an image obtained by taking a picture of a region containing one side of the workpiece while the second surface of the workpiece is held on the holding surface of the chuck table, acquiring the orientation of the side in an XY plane parallel to the holding surface, and acquiring four XY coordinates showing the positions of the four sides in the XY plane based on displacement information obtained by measuring the height of the regions containing the four sides of the workpiece; and a processing step, which involves processing the workpiece according to the orientation of the side and the four XY coordinates.

[0012] In one and another embodiment of the present invention, the orientation of any side of the first surface of the workpiece and four XY coordinates indicating the positions of the four sides of the first surface are obtained, so that the workpiece can be processed with high precision based on these orientations and coordinates. Attached Figure Description

[0013] Figure 1 This is a three-dimensional view showing a laser processing device.

[0014] Figure 2 This is a flowchart illustrating the processing method for the workpiece.

[0015] Figure 3 This is a top view showing an outline of the acquisition steps.

[0016] Figure 4 This is a side view showing the measurement of the height of the workpiece.

[0017] Figure 5 This is a graph showing an example of displacement information.

[0018] Figure 6 This is a top view showing an outline of the first coordinate acquisition step.

[0019] Figure 7 This is a top view showing an outline of the second coordinate acquisition step.

[0020] Figure 8 This is a side view showing an outline of the processing steps.

[0021] Figure 9 This is a flowchart illustrating the processing method of the workpiece in the first modified example.

[0022] Figure 10 This is a top view showing a summary of the first coordinate acquisition step in the first variation example.

[0023] Figure 11 This is a top view showing a summary of the second coordinate acquisition step in the first variation example.

[0024] Label Explanation

[0025] 11: Workpiece; 11a: First side (front); 11b: Second side (back); 11c: Edge; 11d: Edge; 11e: Edge; 11f: Edge; 13: Belt (dicing belt); 15: Frame; 17: Modified layer; 21a: First straight line; 21b: Second straight line; 21c: Third straight line; 21d: Fourth straight line; 31a: First straight line; 31b: Second straight line; 31c: Third straight line; 2: Laser processing device (processing equipment); 4: Base; 4a: Storage part; 6: Support structure; 6a: Support arm; 8: Box support platform; 10: Box; 12: Alignment unit; 14: Conveying unit; 16: Moving mechanism (processing feed mechanism, indexing) 18: Y-axis guide rail; 20: Y-axis moving stage; 22: Y-axis ball screw; 24: Y-axis pulse motor; 26: X-axis guide rail; 28: X-axis moving stage; 30: X-axis ball screw; 32: X-axis pulse motor; 34: θ-axis worktable; 34a: worktable base; 36: chuck worktable; 38: frame; 38a: recess; 38b: flow path; 40: holding plate; 40a: holding surface; 42: fixture; 44: irradiation head (processing unit); 44a: laser beam; 46: camera (shooting unit); 48: displacement measuring device (measuring device); 48a: laser beam; 50: control unit; 50a: calculation unit; 50b: storage unit. Detailed Implementation

[0026] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a perspective view showing the laser processing apparatus (processing apparatus) 2 used in this embodiment. Additionally, in Figure 1 In this description, some components of the laser processing apparatus 2 are omitted. Furthermore, the X direction (forward / backward direction, processing feed direction), Y direction (left / right direction, indexing feed direction), and Z direction (vertical direction, infeed feed direction) used in the following description are perpendicular to each other.

[0027] like Figure 1 As shown, the laser processing apparatus 2 has a base 4 that supports multiple components. A columnar or wall-shaped support structure 6 protruding upwards is provided at the rear end of the base 4. Additionally, a columnar storage portion 4a protruding upwards is provided at the front corner of the base 4.

[0028] An opening is formed on the upper surface of the storage section 4a. A space is formed inside the storage section 4a that leads to the outside through the opening on the upper surface, and a box support 8 with a generally flat upper surface and a lifting mechanism (not shown) for raising and lowering the box support 8 are housed therein. A box 10 capable of storing multiple workpieces 11 is placed on the upper surface of the box support 8 exposed from the opening of the storage section 4a.

[0029] The workpiece 11 is formed into a plate shape, for example, using a glass material that is transparent in the visible light region. The workpiece 11 has: a rectangular first surface (front) 11a having four sides; and a rectangular second surface (back) 11b located on the opposite side of the first surface 11a (see reference). Figure 4 (etc.). No devices or other structures are provided on the first surface 11a and the second surface 11b of the workpiece 11.

[0030] Additionally, a strip (slicing strip) 13 with a diameter larger than that of the workpiece 11 is attached to the second surface 11b of the workpiece 11. The outer periphery of the strip 13 is fixed to an annular frame 15 arranged around the workpiece 11. That is, the workpiece 11 is stored in the box 10 with the support of the frame 15 by means of the strip 13.

[0031] However, there are no restrictions on the material, shape, structure, or size of the workpiece 11. For example, a substrate made of materials such as semiconductors (e.g., silicon), ceramics, resins, or metals can also be used as the workpiece 11. Similarly, devices such as ICs (Integrated Circuits) or LEDs (Light Emitting Diodes) can be formed on the workpiece 11. In addition, the workpiece 11 can be supported on the frame 15 without the aid of the strap 13.

[0032] An alignment unit 12 is disposed adjacent to the storage section 4a. This alignment unit 12 is capable of approximately aligning the frame 15 supporting the workpiece 11. The alignment unit 12 includes, for example, a pair of guide rails that move closer and further away while maintaining a state parallel to the Y direction. Each guide rail has a bottom surface that supports the frame 15 and a side surface perpendicular to the bottom surface.

[0033] For example, by placing the frame 15 removed from the box 10 onto the guide rail of the alignment unit 12 and clamping the frame 15 in the X direction using the guide rail, the frame 15 (i.e., the workpiece 11) can be aligned with a predetermined position. A conveying unit 14 for conveying the frame 15 is disposed above the alignment unit 12.

[0034] A moving mechanism (machining feed mechanism, indexing feed mechanism) 16 is arranged in the area to the side of the alignment unit 12. The moving mechanism 16 has a pair of Y-axis guide rails 18 fixed to the upper surface of the base 4 and substantially parallel to the Y direction. A Y-axis moving stage 20 is slidably mounted on the Y-axis guide rails 18.

[0035] A nut portion (not shown) is provided on the lower surface of the Y-axis moving stage 20. A Y-axis ball screw 22, which is approximately parallel to the Y-axis guide rail 18, is rotatably connected to this nut portion. A Y-axis pulse motor 24 is connected to one end of the Y-axis ball screw 22. If the Y-axis ball screw 22 is rotated by the Y-axis pulse motor 24, the Y-axis moving stage 20 moves along the Y-axis guide rail 18 in the Y direction.

[0036] A pair of X-axis guide rails 26, approximately parallel to the X direction, are fixed on the upper surface of the Y-axis moving stage 20. An X-axis moving stage 28 is slidably mounted on the X-axis guide rails 26. A nut portion (not shown) is provided on the lower surface of the X-axis moving stage 28.

[0037] An X-axis ball screw 30, approximately parallel to the X-axis guide rail 26, is rotatably connected to the nut section. An X-axis pulse motor 32 is connected to one end of the X-axis ball screw 30. If the X-axis ball screw 30 is rotated using the X-axis pulse motor 32, the X-axis moving stage 28 moves along the X-axis guide rail 26 in the X direction.

[0038] A θ stage 34 is provided on the upper surface of the X-axis moving stage 28. The θ stage 34 includes: a stage base 34a (see reference). Figure 4 The chuck table 36 is configured to rotate about a rotation axis that is approximately parallel to the Z direction; and a rotation drive source (not shown) such as an electric motor is connected to the table base 34a. A chuck table 36 is fixed on the upper surface of the table base 34a.

[0039] The chuck worktable 36, for example, includes a disc-shaped frame 38 formed using a metal such as stainless steel (see reference). Figure 4 (etc.). A recess 38a with a circular opening at the upper end is formed on the upper surface side of the frame 38 (see reference). Figure 4 (etc.). A disc-shaped retaining plate 40, which is made of porous material such as ceramic, is fixed in the recess 38a (see reference). Figure 4 (etc.). The upper surface of the retaining plate 40 becomes a retaining surface 40a that is approximately parallel to the X and Y directions and holds the workpiece 11 on the second surface 11b side across the belt 13.

[0040] The lower surface of the retaining plate 40 is connected to a suction source (not shown) such as an injector via a flow path 38b and a valve (not shown) provided inside the frame 38. Therefore, if the belt 13 is brought into contact with the retaining surface 40a and the valve is opened to apply negative pressure from the suction source, the workpiece 11 is attracted by the chuck table 36 through the belt 13. Four clamps 42 are arranged around the chuck table 36, which can fix the annular frame 15 supporting the workpiece 11 from four directions.

[0041] A support arm 6a protruding from the front surface is provided on the support structure 6. An irradiation head (processing unit) 44 is disposed at the front end of the support arm 6a. This irradiation head 44, for example, uses a laser beam 44a (refer to) pulsed by a laser oscillator (processing unit) (not shown). Figure 8 Illuminate the object below.

[0042] There is no particular limitation on the wavelength of the laser beam 44a generated by the laser oscillator, but in this embodiment, a laser oscillator capable of generating a laser beam 44a with a wavelength that can pass through the workpiece 11 (transmissive laser beam 44a) is used. The laser beam 44a of such wavelength is focused into the interior of the workpiece 11, for example, through the irradiation head 44, thereby modifying the interior of the workpiece 11.

[0043] A camera (image capturing unit) 46 is disposed on one side of the irradiation head 44 in the X direction. The camera 46 includes, for example, a two-dimensional light sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor that is sensitive to light in the visible light region, and an imaging lens, and captures an image of the workpiece 11 held by the chuck stage 36 on the upper surface side (first surface 11a side) to generate an image of the workpiece 11.

[0044] An optical displacement measuring device (measuring device) 48 is disposed on one side of the camera 46 in the X direction. This displacement measuring device 48 uses a laser beam to measure the distance between itself and an object. This displacement measuring device 48 includes, for example, irradiating the object below with a laser beam 48a (see reference). Figure 4 The irradiation unit and the light receiving unit that receive the laser beam 48a reflected by the object measure the height of the upper surface (first surface 11a) of the workpiece 11 held by the chuck table 36 and generate displacement-related information (hereinafter referred to as displacement information).

[0045] The lifting mechanism for raising and lowering the box support table 8, the alignment unit 12, the conveying unit 14, the Y-axis pulse motor 24 and the X-axis pulse motor 32 of the moving mechanism 16, the rotary drive source for the θ worktable 34, the valve connected to the chuck worktable 36, the irradiation head 44 or laser oscillator, the camera 46, the displacement measuring device 48, and other components are all connected to the control unit 50. The control unit 50 controls the above-mentioned components according to a series of processes required for processing the workpiece 11.

[0046] The control unit 50 is, for example, a computer, which includes: an arithmetic unit 50a, which is composed of a processing device such as a CPU (Central Processing Unit); and a storage unit 50b, which is composed of a main storage device such as DRAM (Dynamic Random Access Memory) and an auxiliary storage device such as flash memory. The arithmetic unit 50a and the like are operated according to the software stored in the storage unit 50b, thereby realizing the function of the control unit 50. However, the function of the control unit 50 can also be implemented solely through hardware.

[0047] The workpiece 11 (frame 15), for example, taken out of the box 10 and aligned with a predetermined position by the alignment unit 12, is moved into the chuck table 36 using the transfer unit 14, and held on the second surface 11b side by the holding surface 40a. At this time, due to the accuracy of the position of the tape 13 attached to the workpiece 11 and the accuracy of the transfer action of the transfer unit 14, there are many cases where the position of the workpiece 11 moved into the chuck table 36 is offset from the position of the target workpiece 11.

[0048] Therefore, in this embodiment, in order to eliminate the influence of such positional offset, the workpiece 11 is processed after obtaining information such as its orientation and position. Figure 2 This is a flowchart illustrating the processing method of the workpiece according to this embodiment. For example... Figure 2 As shown, in the processing method of the workpiece in this embodiment, the orientation acquisition step ST11 is performed first to acquire the orientation of the edge of the first surface 11a of the workpiece 11. Figure 3 This is a top view showing an outline of obtaining step ST11. Additionally, in Figure 3 In the text, some elements, such as those with the number 13, have been omitted.

[0049] In the orientation acquisition step ST11, the height of the region containing at least one edge 11c of the workpiece 11 is first measured, and the XY coordinates showing the position of the edge 11c are calculated based on the obtained displacement information. Figure 4 This is a side view showing the measurement of the height of the workpiece 11. Additionally, in Figure 4 In the middle, a portion of the elements are shown in cross-section.

[0050] For example, control unit 50, such as Figure 4As shown, while moving the chuck table 36, which holds the workpiece 11, in the X direction, the displacement measuring device 48 is activated to obtain the relationship between position and height in the X direction. That is, the control unit 50 moves the displacement measuring device 48 relative to the chuck table 36 to measure the height of the region containing the edge 11c of the workpiece 11 on a straight line parallel to the X direction.

[0051] Figure 5 This is a graph illustrating an example of the displacement information obtained through this measurement. As described above, when the displacement measuring device 48 is moved relative to the chuck table 36 to measure the height of the region containing the edge 11c of the workpiece 11 along a straight line parallel to the X direction, displacement information corresponding to the profile of the thickness of the workpiece 11 is obtained along this straight line. The obtained displacement information is stored in the storage unit 50b.

[0052] More specifically, first along Figure 3 The first straight line 21a shown measures the height of the region containing the edge 11c of the workpiece 11. Here, there is a large difference (height difference) between the height of position A where the first straight line 21a intersects with the edge 11c and the height of the position outside the workpiece 11 adjacent to position A.

[0053] Therefore, as Figure 5 As shown, by extracting the positions with larger elevation differences from the obtained displacement information, the X coordinate (X1) of position A can be calculated. Furthermore, the Y coordinates of any position on the first straight line 21a parallel to the X direction are all equal. Therefore, by using information such as the position of the Y-axis moving stage 20 (chuck table 36) during measurement, the Y coordinate (Y1) of position A can be calculated.

[0054] That is, the calculation unit 50a uses the displacement information obtained by measurement to calculate the X coordinate (X1) of the position A where the first straight line 21a intersects the side 11c, and uses information showing the position of the Y-axis moving stage 20 during measurement to calculate the Y coordinate (Y1) of position A. The calculated coordinates (X1, Y1) of position A are stored in the storage unit 50b.

[0055] After measuring the height of the region containing the edge 11c of the workpiece 11 along the first straight line 21a, the same measurement is performed after moving the chuck table 36 (Y-axis moving table 20) in the Y direction. That is, the height of the region containing the edge 11c of the workpiece 11 is measured along a second straight line 21b that is at a different position in the Y direction from the first straight line 21a and is parallel to the X direction.

[0056] Furthermore, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X2) of the position B where the second straight line 21b intersects the edge 11c, and uses information showing the position of the Y-axis moving stage 20 (chuck table 36) during measurement to calculate the Y coordinate (Y2) of position B. The calculated coordinates (X2, Y2) of position B are stored in the storage unit 50b.

[0057] In addition, in this embodiment, the position where the rotation axis of the chuck table 36 intersects with the XY plane parallel to the holding surface 40a is taken as the origin (O), and the coordinates of each position are calculated and shown. However, other positions can also be set as the origin of the coordinate system.

[0058] After calculating the coordinates (X1, Y1) of position A and the coordinates (X2, Y2) of position B, the orientation of edge 11c in the XY plane parallel to the holding surface 40a is obtained using these coordinates. For example, the calculation unit 50a applies trigonometric methods to the coordinates (X1, Y1) of position A and the coordinates (X2, Y2) of position B to calculate the angle (θ1) between edge 11c and the Y direction. The calculated angle (θ1) is stored in the storage unit 50b as the orientation of edge 11c.

[0059] Alternatively, the calculation unit 50a can also calculate the angle between side 11c and the X direction as the orientation of side 11c. In this embodiment, the orientation of side 11c is obtained using the coordinates of position A where the first line 21a intersects with side 11c and the coordinates of position B where the second line 21b intersects with side 11c. However, for example, the orientation of side 11d can also be obtained using the coordinates of two positions on side 11d opposite to side 11c.

[0060] After proceeding to step ST11, as follows Figure 2 As shown, the first coordinate acquisition step ST12 is performed, in which two coordinates showing the positions of the two opposite sides of the workpiece 11 are acquired in the XY plane parallel to the holding surface 40a. Figure 6 This is a top view showing an outline of step ST12, the first coordinate acquisition step. Additionally, in Figure 6 The text also omits some elements, such as those containing the number 13.

[0061] In the first coordinate acquisition step ST12, the control unit 50 first adjusts the orientation of the chuck table 36 about a rotation axis perpendicular to the XY plane, so that the orientation of edge 11c acquired in the orientation acquisition step ST11 becomes parallel to the Y direction. That is, the chuck table 36 is adjusted from... Figure 3 The state shown is rotated by an angle θ1 (in this embodiment, the angle θ1 is rotated clockwise when viewed from above). As a result, the opposing edges 11c and 11d of the workpiece 11 are parallel to the Y direction.

[0062] Then, the control unit 50 moves the chuck table 36, which holds the workpiece 11, in the X direction while activating the displacement measuring device 48 to obtain the position and height relationship in the X direction. Specifically, the displacement measuring device 48 and the chuck table 36 are moved relative to each other to measure the height of the region containing the two opposing edges 11c and 11d of the workpiece 11 along a straight line parallel to the X direction. The obtained displacement information is stored in the storage unit 50b.

[0063] More specifically, first along Figure 6 The third straight line 21c shown measures the height of the region containing the opposite edges 11c and 11d of the workpiece 11. Here, there is a significant difference between the height of position C1, where the third straight line 21c intersects with edge 11c, and the height of the position adjacent to position C1 on the outside of the workpiece 11. Additionally, there is a significant difference between the height of position C2, where the third straight line 21c intersects with edge 11d, and the height of the position adjacent to position C2 on the outside of the workpiece 11.

[0064] Therefore, by extracting the positions with larger elevation differences from the obtained displacement information, the X coordinate (X) of position C1 can be calculated. 31 ) and the X coordinate of position C2 (X 32 Furthermore, the Y-coordinates of any position on the third straight line 21c parallel to the X-direction are equal. Therefore, by using information such as showing the position of the Y-axis moving stage 20 (chuck stage 36) during measurement, the Y-coordinates (Y3) of positions C1 and C2 can be calculated.

[0065] That is, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position C1 where the third line 21c intersects with the side 11c. 31 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y3) of position C1 is calculated. The calculated coordinates (X...) of position C1... 31 Y3) is stored in storage unit 50b.

[0066] Furthermore, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position C2 where the third line 21c intersects with the side 11d. 32 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y3) of position C2 is calculated. The calculated coordinates (X...) of position C2... 32 Y3) is stored in storage section 50b.

[0067] After obtaining the first coordinate in step ST12, as follows: Figure 2As shown, the second coordinate acquisition step ST13 is performed, in which two coordinates showing the positions of the other two opposite sides of the workpiece 11 are acquired in the XY plane parallel to the holding surface 40a. Figure 7 This is a top view showing an outline of step ST13, the second coordinate acquisition step. Additionally, in Figure 7 The text also omits some elements, such as those containing the number 13.

[0068] In the second coordinate acquisition step ST13, firstly, the control unit 50 adjusts the orientation of the chuck table 36 about a rotation axis perpendicular to the XY plane, so that the orientation of edge 11c acquired in the orientation acquisition step ST11 becomes perpendicular to the Y direction. That is, the chuck table 36 is adjusted from... Figure 6 The state shown is rotated by 90° (in this embodiment, viewed from above, it is rotated 90° clockwise). As a result, the opposing edges 11e and 11f of the workpiece 11 are parallel to the Y direction.

[0069] Then, while moving the chuck table 36, which holds the workpiece 11, in the X direction, the control unit 50 activates the displacement measuring device 48 to obtain the position and height relationship in the X direction. Specifically, the displacement measuring device 48 and the chuck table 36 are moved relative to each other to measure the height of the region containing the two opposing edges 11e and 11f of the workpiece 11 along a straight line parallel to the X direction. The obtained displacement information is stored in the storage unit 50b.

[0070] More specifically, first along Figure 7 The fourth straight line 21d shown measures the height of the region containing the opposite edges 11e and 11f of the workpiece 11. Here, there is a significant difference between the height at position D1 where the fourth straight line 21d intersects with edge 11e and the height at a position adjacent to position D1 on the outside of the workpiece 11. Furthermore, there is a significant difference between the height at position D2 where the fourth straight line 21d intersects with edge 11f and the height at a position adjacent to position D2 on the outside of the workpiece 11.

[0071] Therefore, by extracting the positions with larger elevation differences from the obtained displacement information, the X coordinate (X) of position D1 can be calculated. 41 ) and the X coordinate of position D2 (X 42 Furthermore, the Y-coordinates of any position on the fourth straight line 21d parallel to the X direction are all equal. Therefore, by using information such as showing the position of the Y-axis moving stage 20 (chuck stage 36) during measurement, the Y-coordinates (Y4) of positions D1 and D2 can be calculated.

[0072] That is, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position D1 where the fourth line 21d intersects with the side 11e.41 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y4) of position D1 is calculated. The calculated coordinates (X4) of position D1 are... 41 Y4) is stored in storage section 50b.

[0073] Furthermore, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position D2 where the fourth line 21d intersects with the side 11f. 42 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y4) of position D2 is calculated. The calculated coordinates (X4) of position D2 are... 42 Y4) is stored in storage section 50b.

[0074] As described above, after measuring the height of the workpiece 11 along the third straight line 21c, the chuck table 36 is rotated by 90° when measuring the height of the workpiece 11 along the fourth straight line 21d. Therefore, even if the coordinates (X, C, D) of position C1 are used directly... 31 The coordinates of position C2 (X, Y3) and position C2 (X, Y3) 32 (Y3) and the coordinates of position D1 (X) 41 The coordinates of position D2 (X, Y4) and position D2 (X, Y4) 42 ,Y4), also cannot properly express the position of the processed object 11.

[0075] Therefore, after obtaining the second coordinate in step ST13, as follows Figure 2 As shown, step ST14 is performed to obtain the coordinates of position C1 (X). 31 The coordinates of position C2 (X, Y3) and position C2 (X, Y3) 32 (Y3) and the coordinates of position D1 (X) 41 The coordinates of position D2 (X, Y4) and position D2 (X, Y4) 42 The calibration coordinates are obtained by correcting one of the two coordinates (Y1, Y2, Y4).

[0076] Specifically, for example, the arithmetic unit 50a implements the coordinates (X) of position D1. 41 The coordinates of position D2 (X, Y4) and position D2 (X, Y4) 42 The system performs calculations to rotate the coordinates of position D1 and position D2 by -90° (in this embodiment, the coordinates are rotated 90° counterclockwise when viewed from above) respectively, and obtains the corrected coordinates of position D1 and position D2 (corrected coordinates). The obtained corrected coordinates of position D1 and position D2 are stored in the storage unit 50b.

[0077] For the control unit 50 of the cutting device 2, the shape of the workpiece 11 (the shape of the first surface 11a) is known. Therefore, the corrected coordinates of position D1 and position D2, as well as the coordinates of position C1 (X) obtained in this way, are used to determine the corrected coordinates. 31 The coordinates of position C2 (X, Y3) and position C2 (X, Y3) 32 (Y3), the control unit 50 is able to properly grasp the position of the workpiece 11.

[0078] In addition, while the coordinates of the corrected position D1 and position D2 are obtained in this embodiment, the coordinates of the corrected position C1 and position C2 can also be obtained. In this case, the following calculation is performed: based on the coordinates of position D1 (X... 41 The coordinates of position D2 (X, Y4) and position D2 (X, Y4) 42 Y4), so that the coordinates of position C1 (X 31 The coordinates of position C2 (X, Y3) and position C2 (X, Y3) 32 Y3) are rotated by 90° respectively (in this embodiment, the angle of rotation is 90° clockwise when viewed from above).

[0079] Following the coordinate correction acquisition step ST14, a processing step ST15 is performed to process the workpiece 11 using the position and orientation information obtained through the series of acquisition steps described above (orientation acquisition step ST11, first coordinate acquisition step ST12, second coordinate acquisition step ST13, and coordinate correction acquisition step ST14). Specifically, in processing step ST15, the workpiece 11 is processed based on the orientation of the edges and four XY coordinates indicating the position of each edge. Figure 8 This is a side view showing an outline of processing step ST15. Additionally, in Figure 8 In the middle, some elements are also shown in cross-section.

[0080] In processing step ST15 of this embodiment, the interior of the workpiece 11 is modified along the predetermined processing line. Specifically, firstly, the control unit 50 adjusts the orientation of the chuck table 36 considering the orientation of the aforementioned edges, so that the predetermined processing line of the object is parallel to the X direction. Next, the control unit 50 adjusts the position of the chuck table 36 considering the aforementioned four XY coordinates, so that the position of the irradiation head 44 is aligned above the extension line of the predetermined processing line of the object.

[0081] And, as Figure 8As shown, while irradiating the workpiece 11 with a laser beam 44a from the irradiation head 44, the chuck stage 36 is moved in the X direction. That is, the chuck stage 36 and the irradiation head 44 are moved relative to each other in a direction parallel to the predetermined processing line. Here, the irradiation head 44 is adjusted, for example, in a manner that the laser beam 44a is focused into the interior of the workpiece 11.

[0082] In this way, by focusing a laser beam 44a of a wavelength that transmits through the workpiece 11 (a transparent laser beam 44a) onto the interior of the workpiece 11, the interior of the workpiece 11 is modified to form a modified layer 17. In this embodiment, the chuck stage 36 is moved relative to the irradiation head 44 to irradiate the predetermined processing line with the laser beam 44a, thereby forming the modified layer 17 along the predetermined processing line. The above operation is repeated until the workpiece 11 is processed along all the predetermined processing lines.

[0083] As described above, in the workpiece processing method of this embodiment, the orientation of the edge (edge ​​11c) of the first surface 11a of the workpiece 11 and the four XY coordinates of the positions (positions C1, C2, D1, and D2) of the four edges (edges 11c, 11d, 11e, and 11f) of the first surface 11a are obtained. Therefore, based on these orientations and coordinates, the workpiece 11 can be processed with high precision.

[0084] Furthermore, in the workpiece processing method of this embodiment, a displacement measuring device 48 that measures the distance between the workpiece and the object is used to obtain the orientation of the edge and the four XY coordinates. Therefore, even when the workpiece 11 is transparent or when no structure (pattern) such as a device is formed on the workpiece 11, the position of the workpiece 11 can be accurately determined.

[0085] Therefore, when processing the workpiece 11, the processing method of this embodiment is extremely effective in situations where it is undesirable to irradiate the outer periphery of the workpiece 11 with the laser beam 44a. Furthermore, the processing method of this embodiment can also prevent the erroneous irradiation of the workpiece 11 with the laser beam 44a.

[0086] Furthermore, the present invention is not limited to the embodiments described above, and various modifications and implementations are possible. Figure 9 This is a flowchart illustrating the processing method of the workpiece in the first modified example. For example... Figure 9 As shown, in the processing method of the workpiece in the first modified example, the series of steps for obtaining the orientation of the edges of the workpiece 11 and the four coordinates showing the positions of the four edges of the workpiece 11 are different from those in the above embodiment.

[0087] Specifically, the first coordinate acquisition step ST21 is performed, where the height of the region containing the two opposite sides of the workpiece 11 is measured on two straight lines parallel to the X direction. Based on the obtained displacement information, three or more XY coordinates are obtained, showing three or more positions where the two opposite sides intersect the two straight lines. Figure 10 This is a top view showing an outline of step ST21 for obtaining the first coordinate in the first variation example. Additionally, in Figure 10 The text also omits some elements, such as those containing the number 13.

[0088] In the first coordinate acquisition step ST21 of the first variation, the control unit 50 moves the chuck table 36, which holds the workpiece 11, in the X direction while activating the displacement measuring device 48 to obtain the relationship between position and height in the X direction. That is, the displacement measuring device 48 is moved relative to the chuck table 36 to measure the height of the region containing the two opposite sides of the workpiece 11 on a straight line parallel to the X direction. The obtained displacement information is stored in the storage unit 50b.

[0089] More specifically, first along Figure 10 The first straight line 31a shown measures the height of the region containing the opposite edges 11c and 11d of the workpiece 11. Here, there is a significant difference between the height of position E1, where the first straight line 31a intersects with edge 11c, and the height of a position adjacent to position E1 on the outside of the workpiece 11. Furthermore, there is a significant difference between the height of position E2, where the first straight line 31a intersects with edge 11d, and the height of a position adjacent to position E2 on the outside of the workpiece 11.

[0090] Therefore, by extracting the locations with larger elevation differences from the obtained displacement information, the X coordinate (X) of location E1 can be calculated. 51 ) and the X coordinate of position E2 (X 52 Furthermore, the Y-coordinates of any position on the first straight line 31a parallel to the X direction are all equal. Therefore, by using information such as showing the position of the Y-axis moving stage 20 (chuck stage 36) during measurement, the Y-coordinates (Y5) of positions E1 and E2 can be calculated.

[0091] That is, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position E1 where the first line 31a intersects with the side 11c. 51 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y5) of position E1 is calculated. The calculated coordinates (X5) of position E1 are... 51 Y5) is stored in storage unit 50b.

[0092] Furthermore, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position E2 where the first line 31a intersects the side 11d. 52 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y5) of position E2 is calculated. The calculated coordinates (X5) of position E2 are... 52 Y5) is stored in storage unit 50b.

[0093] After measuring the height of the region containing the opposing edges 11c and 11d of the workpiece 11 along the first straight line 31a, the same measurement is performed after moving the chuck table 36 (Y-axis moving table 20) in the Y direction. That is, the height of the region containing the edges 11c and 11d of the workpiece 11 is measured along a second straight line 31b that is at a different position in the Y direction from the first straight line 31a and is parallel to the X direction.

[0094] Furthermore, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position F1 where the second line 31b intersects with the side 11c. 61 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y6) of position F1 is calculated. The calculated coordinate (X6) of position F1 is... 61 Y6) is stored in storage unit 50b.

[0095] Furthermore, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position F2 where the second line 31b intersects with the side 11d. 62 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y6) of position F2 is calculated. The calculated coordinates (X6) of position F2 are... 62 Y6) is stored in storage unit 50b.

[0096] In addition, in the first coordinate acquisition step ST21 of the first variant, all four XY coordinates of the four positions where the first line 31a and the second line 31b intersect with the sides 11c and 11d are acquired. However, in this invention, it is sufficient to acquire any three of the four XY coordinates.

[0097] After obtaining the first coordinate in step ST21, as follows: Figure 9 As shown, the second coordinate acquisition step ST22 is performed as follows: the height of the region containing the other two opposite sides of the workpiece 11 is measured on a straight line parallel to the X direction, and the two XY coordinates of the two positions where the other two opposite sides intersect with a straight line are obtained based on the obtained displacement information. Figure 11 This is a top view showing an outline of step ST22, the second coordinate acquisition step, in the first modified example. Additionally, in Figure 11The text also omits some elements, such as those containing the number 13.

[0098] In the second coordinate acquisition step ST22, the orientation of the chuck table 36 is first adjusted to be perpendicular to the orientation of the chuck table 36 in the first coordinate acquisition step ST21. That is, the control unit 50 causes the chuck table 36 to move from... Figure 10 The state shown is rotated by 90° (the angle of 90° clockwise rotation when viewed from above in the first variation).

[0099] Then, while moving the chuck table 36, which holds the workpiece 11, in the X direction, the control unit 50 activates the displacement measuring device 48 to obtain the relationship between position and height in the X direction. Specifically, the displacement measuring device 48 is moved relative to the chuck table 36 to measure the height of the region containing the two opposite sides of the workpiece 11 along a straight line parallel to the X direction. The obtained displacement information is stored in the storage unit 50b.

[0100] More specifically, for example, along Figure 11 The third line 31c shown measures the height of the region containing the opposite edges 11e and 11f of the workpiece 11. Here, there is a significant difference between the height of position G1, where the third line 31c intersects with edge 11e, and the height of the position adjacent to position G1 on the outside of the workpiece 11. Furthermore, there is a significant difference between the height of position G2, where the third line 31c intersects with edge 11f, and the height of the position adjacent to position G2 on the outside of the workpiece 11.

[0101] Therefore, by extracting the positions with larger elevation differences from the obtained displacement information, the X coordinate (X) of position G1 can be calculated. 71 ) and the X coordinate of position G2 (X 72 Furthermore, the Y-coordinates of any position on the third straight line 31c parallel to the X-direction are equal. Therefore, by using information such as showing the position of the Y-axis moving stage 20 (chuck stage 36) during measurement, the Y-coordinates (Y7) of positions G1 and G2 can be calculated.

[0102] That is, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position G1 where the third line 31c intersects with the side 11e. 71 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y7) of position G1 is calculated. The calculated coordinates (X7) of position G1 are... 71 Y7) is stored in storage section 50b.

[0103] Furthermore, the calculation unit 50a uses the displacement information obtained through measurement to calculate the X coordinate (X) of the position G2 where the third line 31c intersects with the side 11f.72 Using information such as the position of the Y-axis moving stage 20 during measurement, the Y coordinate (Y7) of position G2 is calculated. The calculated coordinates (X7) of position G2 are... 72 Y7) is stored in storage section 50b.

[0104] After obtaining the second coordinate in step ST22, as follows: Figure 9 As shown, in the orientation acquisition step ST23, the orientation of one of the two opposing sides is obtained based on the two XY coordinates of the two positions where one of the two opposing sides intersects with the two straight lines, which were obtained through the first coordinate acquisition step ST21.

[0105] For example, the coordinates (X) of the position E1 where the opposite side 11c of the arithmetic unit 50a intersects with the first line 31a. 51 The coordinates (X, Y5) and the position F1 where the edge 11c intersects the second line 31b 61 (Y6) Using trigonometric methods, calculate the angle (θ2) between side 11c and the Y direction. The calculated angle (θ2) is stored in storage unit 50b as the orientation of side 11c.

[0106] Additionally, the calculation unit 50a can also calculate the angle between side 11c and the X direction as the orientation of side 11c. Furthermore, the calculation unit 50a can calculate the coordinates (X, X) of the position E2 where side 11d intersects the first line 31a. 52 The coordinates (X, Y5) and the position F2 where the edge 11d intersects the second line 31b 62 (Y6) Apply the trigonometric method to calculate the angle between side 11d and the Y or X direction.

[0107] After orientation acquisition step ST23, a correction coordinate acquisition step ST24 is performed. Based on the orientation of the edge obtained through orientation acquisition step ST23, the two XY coordinates obtained through the first coordinate acquisition step ST21 and the two XY coordinates obtained through the second coordinate acquisition step ST22 are corrected to obtain the correction coordinates.

[0108] Specifically, for example, the calculation unit 50a calculates the coordinates (X) of the position E1 where the edge 11c intersects the first line 31a. 51 The coordinates (X, Y5) and the position E2 where the edge 11d intersects the first line 31a 52 The system performs calculations to rotate the coordinates of position E1 and position E2 by an angle of θ2 (in this embodiment, the angle of rotation is clockwise when viewed from above) respectively, and obtains the corrected coordinates of position E1 and position E2 (corrected coordinates). The obtained corrected coordinates of position E1 and position E2 are stored in the storage unit 50b.

[0109] Additionally, the calculation unit 50a can implement the coordinates (X, X) of the position F1 where the edge 11c intersects the second line 31b. 61 The coordinates (X, Y6) and the position F2 where the edge 11d intersects the second line 31b 62 The coordinates of position F1 and position F2 are obtained by performing calculations on the angles of rotation θ2 (in this embodiment, the angle of rotation θ2 is clockwise when viewed from above) respectively.

[0110] In addition, the calculation unit 50a calculates the coordinates (X) of the position G1 where the edge 11e intersects the third line 31c. 71 The coordinates (X, Y7) and the position G2 where the edge 11f intersects with the third line 31c. 72 The system performs calculations to rotate the coordinates of position G1 and position G2 by angles θ2-90° (in this embodiment, the angles are rotated clockwise by angles θ2-90° when viewed from above) respectively, and obtains the corrected coordinates of position G1 and position G2 (corrected coordinates). The obtained corrected coordinates of position G1 and position G2 are stored in the storage unit 50b.

[0111] The correction coordinates obtained in this way show positions E1, E2, G1, and G2 when the orientation of edge 11c is adjusted to be parallel to the Y direction. Therefore, by using these correction coordinates, the workpiece 11 can be machined with good accuracy. Furthermore, correction coordinates showing each position when the orientation of edge 11c is adjusted to be perpendicular to the Y direction can be obtained using the same method.

[0112] Following the coordinate correction acquisition step ST24, a processing step ST25 is performed to process the workpiece 11 using information related to its position and orientation obtained through the series of acquisition steps described above (first coordinate acquisition step ST21, second coordinate acquisition step ST22, orientation acquisition step ST23, and coordinate correction acquisition step ST24). Specifically, in processing step ST25, the workpiece 11 is processed based on the orientation of the edges and four XY coordinates indicating the position of each edge. The specific steps of processing step ST25 can be the same as processing step ST15 in the embodiment.

[0113] In the processing method of the workpiece in the first modified example, the orientation of the edge (edge ​​11c) of the first surface 11a of the workpiece 11 and the four XY coordinates of the positions (position E1, position E2, position G1 and position G2) of the four edges (edge ​​11c, edge 11d, edge 11e and edge 11f) of the first surface 11a are also obtained. Therefore, based on these orientations and coordinates, the workpiece 11 can be processed with high precision.

[0114] In addition, in the processing method of the workpiece in the first modified example, a displacement measuring device 48 that measures the distance between the workpiece and the object is also used to obtain the orientation of the edge and the four XY coordinates. Therefore, even if the workpiece 11 is transparent or if no structure (pattern) such as a device is formed on the workpiece 11, the position of the workpiece 11 can be accurately determined.

[0115] Therefore, when processing the workpiece 11, the workpiece processing method of the first modified example is extremely effective in cases where it is undesirable to irradiate the outer periphery of the workpiece 11 with the laser beam 44a. In addition, according to the workpiece processing method of the first modified example, it is also possible to prevent the erroneous irradiation of the outer periphery of the workpiece 11 with the laser beam 44a.

[0116] In addition, in the above embodiment, the orientation of the edge of the first surface 11a of the workpiece 11 is obtained by using displacement information obtained by using displacement measuring device 48. However, for example, the orientation of the edge of the first surface 11a can also be obtained by using camera 46 to take pictures of the workpiece 11.

[0117] That is, in the orientation acquisition step of the workpiece processing method in this second variation, for example, based on an image obtained by taking a picture of a region containing one side of the workpiece 11 using camera 46, the calculation unit 50a calculates the coordinates of two positions on the side, thereby obtaining the orientation of the side. Other steps are the same as in the above embodiment.

[0118] Furthermore, in the above-described embodiments and variations, the second coordinate acquisition steps ST13 and ST22 are performed after the first coordinate acquisition step ST12 and ST21, but these orders can be interchanged. Additionally, in the first variation described above, the orientation acquisition step ST23 is performed after the second coordinate acquisition step ST22, but the orientation acquisition step ST23 can also be performed after the first coordinate acquisition step ST21 and before the second coordinate acquisition step ST22.

[0119] Furthermore, in the above-described embodiments and variations, a modified layer 17 is formed in the workpiece 11 during processing steps ST15 and ST25. However, in the processing steps of this invention, the workpiece 11 can also be ablated using a laser beam. In this case, a laser processing apparatus having a laser oscillator capable of generating a laser beam (an absorptive laser beam) at a wavelength absorbed by the workpiece 11 is used.

[0120] Alternatively, in the processing steps of the present invention, the workpiece 11 can also be processed by using a method in which a ring-shaped cutting tool (processing unit) formed by fixing abrasive grains with a bonding agent cuts into the workpiece 11. In this case, for example, a cutting device (processing apparatus) having a spindle (processing unit) with a ring-shaped cutting tool mounted on it can be used instead of the irradiation head 44 and the laser oscillator.

[0121] In addition, in the above-described embodiments and various modifications, an optical displacement measuring device 48 that uses a laser beam 48a to measure the distance between itself and the object is used. However, a back pressure sensor, an ultrasonic sensor, or the like can be used as the displacement measuring device (measuring instrument) instead of such an optical displacement measuring device 48.

[0122] Furthermore, the processing methods for the workpieces described in the above-described embodiments and variations can be implemented with the relationship between the X and Y directions substituting within a range that does not produce contradictions. For example, in the above-described embodiments and variations, the height of a region containing arbitrary sides is measured by moving the chuck table 36 and the displacement measuring device 48 relatively in the X direction, but the height of a region containing arbitrary sides can also be measured by moving the chuck table 36 and the displacement measuring device 48 relatively in the Y direction.

[0123] In addition, the coordinates of any position of the workpiece 11 (e.g., the coordinates of the center of gravity of the workpiece 11) can be obtained based on the orientation of the edge and the four XY coordinates obtained in the above embodiments and various modifications, and can be used for subsequent processing of the workpiece 11.

[0124] In addition, the above-described embodiments and variations in structure and method can be appropriately modified and implemented as long as they do not depart from the scope of the present invention.

Claims

1. A method of processing a workpiece, the workpiece being a plate-shaped workpiece having a first surface of a rectangular shape including four sides and a second surface of a rectangular shape located on the opposite side of the first surface, the method of processing the workpiece being used when the workpiece is processed using a chuck table having a holding surface and a processing unit that processes the workpiece held by the chuck table, wherein the method of processing the workpiece includes the steps of: an acquisition step of acquiring an angle of a side with an X direction or a Y direction as an orientation of the side in an XY plane parallel to the holding surface and four XY coordinates showing positions of four sides in the XY plane, from displacement information corresponding to a profile of a thickness of the workpiece, obtained by measuring heights of regions including the four sides of the workpiece along straight lines parallel to the X direction or the Y direction in a state where the second surface side of the workpiece is held on the holding surface of the chuck table; and a processing step of processing the workpiece based on the orientation of the side and the four XY coordinates.

2. The method of processing the workpiece according to claim 1, wherein the acquisition step further includes the steps of: an orientation acquisition step of moving the chuck table relative to a measurer for measuring heights, thereby measuring heights of regions including one side of the workpiece on two straight lines parallel to the X direction at different positions in the Y direction, calculating XY coordinates showing two positions at which the side intersects the two straight lines from the obtained displacement information, and thereby acquiring the orientation of the side; a first coordinate acquisition step of, after adjusting an orientation of the chuck table about a rotation axis perpendicular to the XY plane so that the orientation of the side acquired by the orientation acquisition step becomes parallel to the Y direction, moving the measurer relative to the chuck table, thereby measuring heights of regions including two opposite sides of the workpiece on one straight line parallel to the X direction, and acquiring two XY coordinates showing two positions at which the two opposite sides intersect the one straight line from the obtained displacement information; and a second coordinate acquisition step of, after adjusting the orientation of the chuck table about the rotation axis so that the orientation of the side acquired by the orientation acquisition step becomes perpendicular to the Y direction, moving the measurer relative to the chuck table, thereby measuring heights of the regions including the other two opposite sides of the workpiece on one straight line parallel to the X direction, and acquiring the two XY coordinates showing the two positions at which the other two opposite sides intersect the one straight line from the obtained displacement information.

3. The method of processing the workpiece according to claim 1, wherein the acquisition step further comprises the steps of: ​ ​ ​ ​ ​ ​ ​ ​ ​ The first coordinate acquisition step moves the chuck table relative to a measurer for measuring height, thereby measuring the height of a region including the two opposite edges of the workpiece on two straight lines parallel to the X direction at different positions in the Y direction, and acquires three or more XY coordinates showing three or more positions at which the two opposite edges intersect the two straight lines, from displacement information obtained thereby; The second coordinate acquisition step moves the measurer relative to the chuck table in a state in which the orientation of the chuck table about the rotation axis perpendicular to the XY plane is perpendicular to the orientation of the chuck table in the first coordinate acquisition step, thereby measuring the height of a region including the other two opposite edges of the workpiece on one straight line parallel to the X direction, and acquires two XY coordinates showing two positions at which the other two opposite edges intersect the one straight line, from displacement information obtained thereby; The orientation acquisition step acquires the orientation of one of the two opposite edges, from the two XY coordinates showing two positions at which one of the two opposite edges intersects the two straight lines, acquired by the first coordinate acquisition step; and The corrected coordinate acquisition step corrects the two XY coordinates showing two positions at which the two opposite edges intersect one of the two straight lines, acquired by the first coordinate acquisition step, and the two XY coordinates acquired by the second coordinate acquisition step, according to the orientation of the edge acquired by the orientation acquisition step, and acquires four corrected XY coordinates.

4. A workpiece processing method for a workpiece that is a plate-shaped workpiece having a first surface of a rectangular shape including four edges and a second surface of a rectangular shape located on the opposite side of the first surface, the workpiece processing method being used when the workpiece is processed using a chuck table having a holding surface and a processing unit that processes the workpiece held by the chuck table, wherein the workpiece processing method includes the following steps: an acquisition step that acquires an angle formed by one edge of the workpiece with the X direction or the Y direction as an orientation of the edge in an XY plane parallel to the holding surface of the chuck table, from an image obtained by photographing a region including the edge in a state in which the second surface side of the workpiece is held on the holding surface of the chuck table, and acquires four XY coordinates showing positions of the four edges in the XY plane, from displacement information corresponding to a profile of a thickness of the workpiece obtained by measuring the height of a region including the four edges of the workpiece along a straight line parallel to the X direction or the Y direction; and a processing step that processes the workpiece according to the orientation of the edge and the four XY coordinates. the workpiece processing method includes the following steps:

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