Grinding system, grinding method, and program

Abstract

This grinding device comprises: a holding unit for holding a substrate; a drive unit for pressing a grinding tool against the substrate held by the holding unit; a measurement unit for measuring the thickness of the substrate during grinding of the substrate; an adjustment unit for adjusting the inclination of the holding unit with respect to the drive unit; and a control circuit. The measurement unit includes a first contact that contacts the holding unit, a first measuring instrument that measures displacement of the first contact, a second contact that contacts the substrate held by the holding unit, and a second measuring instrument that measures displacement of the second contact. The measurement unit measures the thickness of the substrate during grinding of the substrate on the basis of the relative positions of the first contact and the second contact. The control circuit performs control to correct a measurement value of the measurement unit in accordance with a change in the inclination.

Description

Grinding Device, Grinding Method, and Program 【0001】 The present disclosure relates to a grinding device, a grinding method, and a program. 【0002】 In the processing method described in Patent Document 1, in the step of grinding a wafer, the height of the grinding surface of the wafer is measured, and when the height of the grinding surface reaches a desired height, that is, when the thickness of the wafer reaches the target thickness, the lowering of the grinding wheel is stopped. Further, this processing method adjusts the relative inclination of the chuck holding the wafer and the grinding stone based on the thickness distribution of the wafer after grinding. 【0003】 Japanese Patent Application Laid-Open No. 2022-125928 【0004】 One embodiment of the present disclosure provides a technique for accurately measuring the thickness of a substrate during grinding of the substrate. 【0005】 A grinding device according to an embodiment of the present disclosure includes a holding unit that holds a substrate, a driving unit that presses a grinding tool against the substrate held by the holding unit, a measuring unit that measures the thickness of the substrate during grinding of the substrate, an adjusting unit that adjusts the inclination of the holding unit with respect to the driving unit, and a control circuit. The measuring unit includes a first contact that contacts the holding unit, a first measuring instrument that measures the displacement of the first contact, a second contact that contacts the substrate held by the holding unit, and a second measuring instrument that measures the displacement of the second contact, and measures the thickness of the substrate during grinding of the substrate based on the relative positions of the first contact and the second contact. The control circuit performs control to correct the measurement value of the measuring unit in accordance with a change in the inclination of the holding unit. 【0006】 According to one embodiment of the present disclosure, the thickness of the substrate can be accurately measured during grinding of the substrate. 【0007】Figure 1 is a plan view showing a grinding system according to one embodiment. Figure 2 is a cross-sectional view showing an example of the main part of the grinding apparatus. Figure 3 is a cross-sectional view showing an example of the measuring section during substrate grinding. Figure 4 is a cross-sectional view showing an example of the measuring section before substrate grinding. Figure 5 is a cross-sectional view showing an example of the adjustment section. Figure 6 is a plan view showing an example of the holding section, adjustment section, first contact, and second contact. Figure 7 is a flowchart showing an example of a grinding method. Figure 8 is a plan view showing an example of an inspection apparatus. Figure 9 is a cross-sectional view showing an example of an inspection apparatus. 【0008】 Embodiments of this disclosure will be described below with reference to the drawings. In each drawing, identical or similar components are denoted by the same reference numerals, and their descriptions may be omitted. In each drawing, the X-axis, Y-axis, and Z-axis directions are perpendicular to each other, the X-axis and Y-axis directions are horizontal, and the Z-axis direction is vertical. 【0009】 The X-axis direction includes the positive X-axis direction and the negative X-axis direction, which is the opposite direction to the positive X-axis direction. The Y-axis direction includes the positive Y-axis direction and the negative Y-axis direction, which is the opposite direction to the positive Y-axis direction. The Z-axis direction includes the positive Z-axis direction and the negative Z-axis direction, which is the opposite direction to the positive Z-axis direction. The positive Z-axis direction is upward, and the negative Z-axis direction is downward. 【0010】 Referring to Figure 1, a grinding system 1 according to one embodiment will be described. The grinding system 1 includes an input / output station 2. The input / output station 2 includes a mounting table 20. Multiple cassettes C are placed on the mounting table 20. Each cassette C contains a substrate W. One cassette C contains a substrate W before processing at the processing station 3. Another cassette C contains a substrate W after processing at the processing station 3. 【0011】The loading / unloading station 2 comprises a second transport area 21 and a second transport device 22. The second transport area 21 is adjacent to the mounting table 20 and the transition device 30. The second transport device 22 transports substrates W between multiple devices adjacent to the second transport area 21. The second transport device 22 has a transport arm for holding substrates W and a drive unit for moving or rotating the transport arm. The transport arm is capable of moving horizontally (in both the X-axis and Y-axis directions) and vertically, and rotating about the vertical axis. Multiple transport arms may be provided. 【0012】 The grinding system 1 includes a processing station 3. The processing station 3 includes a transition device 30. The transition device 30 is adjacent to the second transport area 21. The transition device 30 is positioned on the opposite side of the mounting table 20 with respect to the second transport area 21. The transition device 30 temporarily stores the substrate W. Multiple transition devices 30 may be provided in the vertical direction. 【0013】 At least one transition device 30 may also function as an alignment device. The alignment device detects notches or other features indicating the crystal orientation of the substrate W and orients the notches or other features of the substrate W to the desired orientation. The substrate W may have orientation flats instead of notches. In addition, at least one transition device 30 may also function as an inversion device. The inversion device inverts the substrate W vertically. 【0014】 The processing station 3 comprises a first transport area 31 and a first transport device 32. The first transport area 31 and the first transport device 32 transport the substrate W between a plurality of devices adjacent to the first transport area 31. The first transport device 32 is, for example, an articulated robot. The articulated robot has a transport arm that holds the substrate W and a drive unit that moves or rotates the transport arm. The transport arm has a suction pad 32a. The suction pad 32a suctions the substrate W. The suction pad 32a can move horizontally (in both the X-axis and Y-axis directions) and vertically, and rotate about the vertical axis. A plurality of transport arms may be provided. 【0015】The processing station 3 includes a grinding device 10. As shown in Figure 2, the grinding device 10 grinds the substrate W by pressing a grinding tool T against the substrate W. In this specification, grinding includes polishing. 【0016】 As shown in Figure 1, the grinding apparatus 10 comprises, for example, four holding parts 11A to 11D, two drive parts 12A to 12B, and a housing 13. The holding parts 11A to 11D hold the substrate W. Holding includes suction. The holding parts 11A to 11D are, for example, vacuum chucks. The drive parts 12A and 12B drive the grinding tool T. The housing 13 houses the holding parts 11A to 11D and the drive parts 12A to 12B inside. The housing 13 suppresses the outflow of particles and mist generated during grinding. The housing 13 has an inlet / outlet 13a. The substrate W is fed into the housing 13 from the outside or out of the housing 13 through the inlet / outlet 13a. 【0017】 The grinding device 10 may include a rotary table 15. The rotary table 15 is provided inside the housing 13. The rotary table 15 is rotated around a rotational centerline R1. The four holding parts 11A to 11D are provided at intervals around the rotational centerline R1 of the rotary table 15 and are rotated together with the rotary table 15. In addition, the four holding parts 11A to 11D are rotated independently around their respective rotational centerlines R2 (see Figure 2). 【0018】 The two holding parts 11A and 11C are arranged symmetrically around the rotation centerline R1 of the rotary table 15. Each holding part 11A and 11C moves between the first loading / unloading position A3, where the first transport device 32 loads and unloads the substrate W, and the first grinding position A1, where the drive unit 12A grinds the substrate W with the grinding tool T. The two holding parts 11A and 11C move between the first loading / unloading position A3 and the first grinding position A1 each time the rotary table 15 rotates 180°. At the first grinding position A1, when grinding the substrate W, a nozzle 16 (see Figure 2) supplies a grinding fluid such as water to the upper surface of the substrate W. The nozzle 16 is located inside the housing 13. 【0019】The other two holding parts 11B and 11D are arranged symmetrically around the rotation centerline R1 of the rotary table 15. Each holding part 11B and 11D moves between the second loading / unloading position A0, where the first transport device 32 loads and unloads the substrate W, and the second grinding position A2, where the drive unit 12B grinds the substrate W with the grinding tool T. The other two holding parts 11B and 11D move between the second loading / unloading position A0 and the second grinding position A2 each time the rotary table 15 rotates 180°. At the second grinding position A2, similar to the first grinding position A1, a nozzle supplies a grinding fluid such as water to the upper surface of the substrate W when grinding the substrate W. 【0020】 When viewed from above, the first loading / unloading position A3, the second loading / unloading position A0, the first grinding position A1, and the second grinding position A2 are arranged in this order in a counterclockwise direction. In this case, when viewed from above, the holding parts 11A, 11B, 11C, and 11D are arranged in this order in a counterclockwise direction at 90° intervals. 【0021】 Furthermore, the positions of the first loading / unloading position A3 and the second loading / unloading position A0 may be reversed, and the positions of the first grinding position A1 and the second grinding position A2 may also be reversed. In other words, when viewed from above, the first loading / unloading position A3, the second loading / unloading position A0, the first grinding position A1, and the second grinding position A2 may be arranged in this order in a clockwise direction. In this case, when viewed from above, the holding parts 11A, 11B, 11C, and 11D will be arranged in this order in a clockwise direction at 90° intervals. 【0022】 However, the number of holding parts is not limited to four. The number of drive parts is also not limited to two. Furthermore, the rotary table 15 is not required. A sliding table may be provided instead of the rotary table 15. 【0023】 The processing station 3 is equipped with an inspection device 40. The inspection device 40 measures the radial distribution of the thickness of the substrate W after grinding. The inspection device 40 measures the thickness of the substrate W at multiple points in the radial direction of the substrate W. The inspection results of the inspection device 40 are used to adjust the inclination of the holding parts 11A and 11C relative to the drive unit 12A, and to adjust the inclination of the holding parts 11B and 11D relative to the drive unit 12B. 【0024】The grinding system 1 includes a control circuit 9. The control circuit 9 is, for example, a computer. The control circuit 9 includes an arithmetic unit 91 such as a CPU (Central Processing Unit) and a storage unit 92 such as memory. The storage unit 92 stores programs that control various processes performed in the grinding system 1. 【0025】 The program, or computer program product, is supplied in a form recorded on a removable storage medium. The removable storage medium may be a memory card, optical disc, or HDD (Hard Disk Drive). The control circuit 9 reads the program from the removable storage medium and stores it in the storage unit 92. The program may also be pre-written to the storage medium of the storage unit 92. The storage medium of the storage unit 92 may be an HDD, SSD (Solid State Drive), or EEPROM (Electronically Erasable Programmable Read Only Memory). Furthermore, the control circuit 9 may acquire programs distributed by remote server devices via a network or other communication. 【0026】 The control circuit 9 controls the operation of the grinding system 1 by causing the calculation unit 91 to execute a program stored in the memory unit 92. A lower-level control circuit may be provided for each device constituting the grinding system 1 to control the operation of that device, and a higher-level control circuit may be provided to comprehensively control multiple lower-level control circuits. The control circuit 9 may be composed of a lower-level control circuit and a higher-level control circuit. 【0027】 The control circuit 9 includes electronic circuits such as a CPU, GPU (Graphics Processing Unit), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit). The control circuit 9 performs the various control operations described in this specification by executing instruction codes stored in a storage medium such as memory, or by being circuit-designed for special applications. 【0028】An example of the operation of the grinding system 1 shown in Figure 1 will be described below. The following operation is performed under the control of the control circuit 9. First, the second transport device 22 takes the substrate W from the cassette C and transports it to the transition device 30. Next, the first transport device 32 takes the substrate W from the transition device 30 and transports it to the grinding device 10. The first transport device 32, for example, hands over the substrate W to the holding unit 11C at the first loading / unloading position A3. The holding unit 11C holds the substrate W with its first main surface facing upwards. After that, the rotary table 15 is rotated 180° and the holding unit 11C is moved from the first loading / unloading position A3 to the first grinding position A1. 【0029】 Next, the drive unit 12A drives the grinding tool T to grind the first main surface of the substrate W. Then, the rotary table 15 is rotated 180°, and the holding unit 11C is moved from the first grinding position A1 to the first loading / unloading position A3. Subsequently, the first transport device 32 receives the substrate W from the holding unit 11C at the first loading / unloading position A3 and transports it to the transition device 30. After that, the transition device 30 inverts the substrate W upside down. 【0030】 Next, the first transport device 32 removes the substrate W from the transition device 30 and transports it to the grinding device 10. The first transport device 32, for example, at the first loading / unloading position A3, transfers the substrate W to the holding unit (for example, the holding unit 11C). The holding unit 11C holds the substrate W with its second main surface facing upwards. The second main surface is oriented opposite to the first main surface. After that, the rotary table 15 is rotated 180°, and the holding unit 11C is moved from the first loading / unloading position A3 to the first grinding position A1. 【0031】 Next, the drive unit 12A drives the grinding tool T to grind the second main surface of the substrate W. After that, the rotary table 15 is rotated 180°, and the holding unit 11C is moved from the first grinding position A1 to the first loading / unloading position A3. Subsequently, the first transport device 32 receives the substrate W from the holding unit 11C at the first loading / unloading position A3 and transports it to the inspection device 40. 【0032】Next, the inspection device 40 measures the radial thickness distribution of the substrate W. Then, the first transport device 32 removes the substrate W from the inspection device 40 and transports it to the transition device 30. After that, the second transport device 22 removes the substrate W from the transition device 30 and stores it in the cassette C. 【0033】 Both the first and second main surfaces of one substrate W are ground at the same first grinding position A1. Both the first and second main surfaces of another substrate W are ground at the same second grinding position A2. In the latter case, after the first transport device 32 removes the substrate W from the transition device 30, it transfers the substrate W to the holding unit (for example, the holding unit 11D) at the second loading / unloading position A0. Note that of the first and second main surfaces of one substrate W, one side may be ground at the first grinding position A1 and the opposite side at the second grinding position A2. 【0034】 Furthermore, the grinding device 10 may perform multiple processes simultaneously at multiple locations in order to improve throughput. For example, the grinding device 10 grinds the substrate W simultaneously at both the first grinding position A1 and the second grinding position A2. During this time, the grinding device 10 performs, in this order, tasks such as spray cleaning of the substrate W, unloading the substrate W, cleaning the holding surfaces (upper surfaces) of the holding parts 11A, 11B, 11C, or 11D, and loading the substrate W at both the first loading / unloading position A3 and the second loading / unloading position A0. 【0035】 Subsequently, the grinding device 10 rotates the rotary table 15 by 180°. Then, the grinding device 10 grinds the substrate W again simultaneously at both the first grinding position A1 and the second grinding position A2. During this time, the grinding device 10 again performs spray cleaning of the substrate W, unloading of the substrate W, cleaning of the holding surfaces (upper surfaces) of the holding parts 11A, 11B, 11C or 11D, and loading of the substrate W at both the first loading / unloading position A3 and the second loading / unloading position A0, in this order. 【0036】Referring to Figure 2, an example of the grinding apparatus 10 will be described again. The grinding apparatus 10 has a control circuit 14. The control circuit 14 may be part of the control circuit 9 shown in Figure 1. Under the control of the control circuit 14, the grinding apparatus 10 grinds the substrate W by pressing the grinding tool T against the substrate W. The grinding tool T includes, for example, a disc-shaped grinding wheel T1 and a plurality of grinding wheels T2 arranged in a ring shape on the lower surface of the grinding wheel T1. The grinding wheels T2 grind the substrate W. 【0037】 The grinding device 10 includes a holding part 11A. The holding part 11A holds the substrate W from the opposite side (for example, the bottom side) from the grinding tool T. The holding part 11A has a holding surface 111 on its upper surface for holding the substrate W. The holding surface 111 may be a conical surface symmetrical with respect to the rotation center line R2 of the holding part 11A in order to adjust the radial distribution of the thickness of the substrate W. The actual apex angle of the conical surface may be larger than the apex angle shown in Figure 1. Note that the configurations of the holding parts 11B to 11D shown in Figure 1 are the same as the configuration of the holding part 11A shown in Figure 2, so their explanation is omitted. 【0038】 The grinding device 10 includes a second rotating section 17. The second rotating section 17 rotates the holding section 11A. The second rotating section 17 includes, for example, a rotary motor 171 and a rotating shaft 172 that is rotated by the rotary motor 171. The holding section 11A is provided at the upper end of the rotating shaft 172. The rotary motor 171 rotates the holding section 11A together with the rotating shaft 172. The rotational centerline R2 of the holding section 11A may be inclined to adjust the thickness distribution of the substrate W. The second rotating section 17 is provided for each holding section 11A to 11D. 【0039】 The grinding device 10 includes a drive unit 12A. The drive unit 12A drives the grinding tool T. The drive unit 12A has, for example, a rotating unit 121 and a lifting unit 125. The rotating unit 121 holds and rotates the grinding tool T. The lifting unit 125 raises and lowers the grinding tool T together with the rotating unit 121. Note that the configuration of the drive unit 12B shown in Figure 1 is the same as the configuration of the drive unit 12A shown in Figure 2, so its explanation is omitted. 【0040】The rotating part 121 includes, for example, a rotary motor 122, a spindle shaft 123 rotated by the rotary motor 122, and a flange 124 provided at the lower end of the spindle shaft 123. The flange 124 is positioned horizontally, and a grinding tool T is mounted on its lower surface. The rotary motor 122 rotates the spindle shaft 123, thereby rotating the grinding tool T mounted on the lower surface of the flange 124. 【0041】 The lifting unit 125 includes, for example, a Z-axis guide 126, a Z-axis slider 127 that moves along the Z-axis guide 126, and a lifting motor 128 that moves the Z-axis slider 127. A rotary motor 122 is fixed to the Z-axis slider 127 via a motor holder 129. The lifting unit 125 has a ball screw (not shown) that converts the rotational motion of the lifting motor 128 into the linear motion of the Z-axis slider 127. 【0042】 As shown in Figure 3, the grinding apparatus 10 includes a measuring unit 18. The measuring unit 18 measures the thickness of the substrate W during grinding. The measuring unit 18 is provided at both the first grinding position A1 and the second grinding position A2. The measuring unit 18 measures the thickness of the substrate W during grinding of the first main surface or the second main surface of the substrate W. 【0043】 The measuring unit 18 includes a first contact element 181, a first measuring instrument 182, a second contact element 183, and a second measuring instrument 184. The first contact element 181 contacts the holding part 11A. The first measuring instrument 182 measures the displacement of the first contact element 181. The second contact element 183 contacts the substrate W held by the holding part 11A. The second measuring instrument 184 measures the displacement of the second contact element 183. During grinding of the substrate W, the measuring unit 18 measures the thickness of the substrate W based on the relative positions of the first contact element 181 and the second contact element 183. 【0044】 The first contact element 181 contacts the upper surface of the holding part 11A during grinding of the substrate W. Meanwhile, the second contact element 183 contacts the upper surface of the substrate W during grinding of the substrate W. The contact point with the second contact element 183 on the upper surface of the substrate W is not particularly limited, but for example, it is midway between the center and the periphery of the upper surface of the substrate W. The measuring unit 18 measures the thickness of the substrate W during grinding based on the relative height difference between the first contact element 181 and the second contact element 183. 【0045】 As shown in FIG. 4, when both the first contact 181 and the second contact 183 contact the holding portion 11A, the measuring unit 18 stores in a storage medium such as a memory with reference to the relative positions of the first contact 181 and the second contact 183. The measuring unit 18 measures the thickness of the substrate W based on the magnitude of the deviation between the relative positions of the first contact 181 and the second contact 183 and the reference position. 【0046】 The moving directions of the first contact 181 and the second contact 183 are substantially parallel to the thickness direction of the substrate W. Therefore, the magnitude of the deviation corresponds to the thickness of the substrate W. When the moving directions of the first contact 181 and the second contact 183 are inclined with respect to the thickness direction of the substrate W, the product of a constant corresponding to the inclination and the magnitude of the deviation corresponds to the thickness of the substrate W. 【0047】 When the contact point with the second contact 183 on the upper surface of the substrate W is deviated from the center of the upper surface of the substrate W, the measuring unit 18 may measure the thickness of the substrate W at a plurality of points at intervals in the circumferential direction of the substrate W. In this case, the substrate W is ground until the average value of the measured values measured at the plurality of points becomes the set value. The set values are set separately for grinding the first main surface and grinding the second main surface. Note that the substrate W may be ground until the measured value measured at one point becomes the set value. 【0048】 As shown in FIG. 5, the grinding apparatus 10 includes an adjustment unit 19. The adjustment unit 19 adjusts the inclination of the holding portion 11A with respect to the driving unit 12A. For example, the adjustment unit 19 adjusts the inclination of the rotation center line R2 of the holding portion 11A with respect to the rotation center line R3 of the driving unit 12A. The adjustment unit 19 is provided for each of the holding portions 11A, 11B, 11C, and 11D. The adjustment of the inclination of the holding portions 11B, 11C, and 11D is performed in the same manner as the adjustment of the inclination of the holding portion 11A, and thus the description thereof is omitted. 【0049】The adjustment unit 19 adjusts the inclination of the holding unit 11A. This allows the radial distribution of the thickness of the substrate W after grinding to be adjusted to a target distribution. The target distribution may be a uniform or non-uniform distribution of thickness in the radial direction of the substrate W. The target distribution is set according to the application of the substrate W. The change in thickness distribution due to the change in the inclination of the holding unit 11A is investigated in advance by experiment, calculation or machine learning and stored in a storage medium such as memory. 【0050】 The adjustment unit 19 has, for example, a fixed shaft 191, a first lifting shaft 192, and a second lifting shaft 193 spaced apart along the periphery of the holding unit 11A. It is preferable that the fixed shaft 191, the first lifting shaft 192, and the second lifting shaft 193 are provided at a 120° pitch. The fixed shaft 191 fixes the holding unit 11A. The first lifting shaft 192 raises and lowers the holding unit 11A. The second lifting shaft 193 raises and lowers the holding unit 11A independently of the first lifting shaft 192. The change in thickness distribution accompanying the raising and lowering of the first lifting shaft 192 and the second lifting shaft 193 is investigated in advance by experimentation, calculation, or machine learning, and stored in a storage medium such as memory. 【0051】 The fixed shaft 191, the first lifting shaft 192, and the second lifting shaft 193 may each be provided on the peripheral edge of the lower surface of the holding portion 11A. The first lifting shaft 192 raises and lowers the holding portion 11A by extending and retracting the first lifting shaft 192. Similarly, the second lifting shaft 193 raises and lowers the holding portion 11A by extending and retracting the second lifting shaft 193. The first lifting shaft 192 and the second lifting shaft 193 each include actuators such as motors. 【0052】 The configuration of the adjustment unit 19 can be any common configuration and is not limited to the configuration shown in Figure 5. 【0053】 As shown in Figure 6, it is preferable that the fixed shaft 191 of the adjustment unit 19 is located on the rotational centerline R3 of the drive unit 12A. This provides the following effects (A) and (B): (A) The inclination of the rotational centerline R2 of the holding unit 11A with respect to the rotational centerline R3 of the drive unit 12A can be easily calculated based on the raising and lowering of the first lifting shaft 192 or the second lifting shaft 193. (B) Vibration during grinding of the substrate W can be suppressed. 【0054】The first contact 181 and second contact 183 of the measuring unit 18 are positioned outside the rotational trajectory of the grinding wheel T2 so as not to interfere with the grinding of the substrate W. When viewed from a direction along the rotational centerline R3 of the drive unit 12A, it is preferable that the first contact 181 is positioned near the first lifting shaft 192, for example, within 20 mm of the first lifting shaft 192. It is preferable that the second contact 183 is positioned on the line segment connecting the first contact 181 and the rotational centerline R2 of the holding unit 11A. 【0055】 Referring to Figure 7, an example of the operation of the grinding device 10 will be explained again. Steps S101 to S106 shown in Figure 7 are performed under the control of the control circuit 14. The processing from step S101 onwards begins when the substrate W is placed, for example, at the first grinding position A1. First, the grinding device 10 starts grinding the substrate W (step S101). Specifically, the second rotating part 17 rotates the substrate W together with the holding part 11A, and the drive part 12A rotates the grinding tool T and brings the grinding tool T closer to the holding part 11A. The grinding tool T grinds the first main surface or the second main surface of the substrate W. 【0056】 The control circuit 14 monitors the thickness of the substrate W using the measuring unit 18 while grinding the substrate W. The control circuit 14 determines whether the measurement value from the measuring unit 18 has reached a set value (step S102). The control circuit 14 grinds the substrate W until the measurement value from the measuring unit 18 reaches the set value. When the measurement value from the measuring unit 18 reaches the set value, the control circuit 14 terminates the grinding of the substrate W (step S103). Specifically, the drive unit 12A stops the grinding tool T from approaching the holding unit 11A. Then, the drive unit 12A moves the grinding tool T away from the holding unit 11A. After that, the drive unit 12A stops the rotation of the grinding tool T, and the second rotating unit 17 stops the rotation of the substrate W. 【0057】The substrate W is removed from the grinding device 10 and transported to the inspection device 40. The inspection device 40 measures the radial distribution of the thickness of the substrate W after grinding. The inspection device 40 measures the thickness of the substrate W at multiple points in the radial direction of the substrate W. The inspection device 40 transmits a signal indicating the inspection result to the control circuit 14, and the control circuit 14 acquires the inspection result from the inspection device 40 (step S104). Based on the acquired inspection result, the control circuit 14 sets the inclination of the holding part 11A so that the radial distribution of the thickness of the substrate W after grinding of the substrate W held by the same holding part 11A the next time becomes the target distribution. In this embodiment, the inspection device 40 is provided separately from the grinding device 10, but it may also be provided inside the grinding device 10. Details of the inspection device 40 will be described later. 【0058】 The control circuit 14 adjusts the inclination of the holding part 11A by the adjustment unit 19 so that the radial distribution of the thickness of the substrate W after grinding of the substrate W held by the same holding part 11A in the next operation matches the target distribution (step S105). If the inspection result obtained in step S104 deviates from the target distribution, the control circuit 14 controls the adjustment unit 19 to change the inclination of the holding part 11A so that the radial distribution of the thickness of the substrate W after grinding of the substrate W held by the same holding part 11A in the next operation matches the target distribution. This ensures that even if disturbances such as temperature changes occur in the grinding device 10, the radial distribution of the thickness of the substrate W after grinding can be adjusted to match the target distribution. 【0059】 Incidentally, as is clear from Figure 4, when the inclination of the holding portion 11A changes, the contact positions of the first contactor 181 and the second contactor 183 with the holding portion 11A change. The magnitude of this change differs between the first contactor 181 and the second contactor 183. Therefore, if the same reference position as before the change is used after the inclination of the holding portion 11A changes, the measurement error of the measuring unit 18 will increase. 【0060】The control circuit 14 calculates a correction amount for the measurement value of the measuring unit 18 in accordance with the change in the tilt of the holding unit 11A (step S106). The control circuit 14 uses the correction amount calculated in step S106 in subsequent steps S102. In other words, the control circuit 14 corrects the measurement value of the measuring unit 18 in accordance with the change in the tilt of the holding unit 11A. Therefore, the thickness of the substrate W can be measured accurately during grinding of the substrate W. The control circuit 14 monitors the corrected measurement value of the measuring unit 18 during grinding of the substrate W, and stops the approach of the grinding tool T to the holding unit 11A when the corrected measurement value of the measuring unit 18 reaches a set value. This reduces variations in the thickness of the substrate W after grinding. 【0061】 The position in which the first contact element 181 contacts the holding portion 11A mainly changes in accordance with the raising and lowering of the first lifting shaft 192 and the second lifting shaft 193. The change in the position in which the first contact element 181 contacts the holding portion 11A due to the raising and lowering of the first lifting shaft 192 and the second lifting shaft 193 is investigated in advance by experimentation, calculation, or machine learning, and stored in a storage medium such as memory. 【0062】 Similarly, the position in which the second contact element 183 contacts the holding portion 11A changes mainly in accordance with the vertical movement of the first lifting shaft 192 and the second lifting shaft 193. The change in the position in which the second contact element 183 contacts the holding portion 11A due to the vertical movement of the first lifting shaft 192 and the second lifting shaft 193 is investigated in advance by experimentation, calculation, or machine learning, and stored in a storage medium such as memory. 【0063】 The control circuit 14 estimates the change in the reference position based on the upward or downward movement of at least one of the first lifting shaft 192 and the second lifting shaft 193. Based on the change in the reference position, the control circuit 14 calculates a correction amount for the measurement value of the measuring unit 18 and uses it to measure the thickness of the substrate W during subsequent grinding of the substrate W. In other words, the control circuit 14 corrects the measurement value of the measuring unit 18 based on the upward or downward movement of at least one of the first lifting shaft 192 and the second lifting shaft 193. 【0064】The control circuit 14 pre-stores data in a storage medium that represents the change in the position where the first contactor 181 and the second contactor 183 contact the respective holding portion 11A, as the first and second lifting shafts 192 and 193 move up and down. The control circuit 14 corrects the measured value of the measuring unit 18 based on the upward or downward movement of at least one of the first and second lifting shafts 192 and 193 and the aforementioned change data. 【0065】 Preferably, the control circuit 14 corrects the measurement value of the measuring unit 18 during the grinding of the (n+1)th substrate W in accordance with the change in the tilt of the holding unit 11A between the grinding of the nth substrate W and the grinding of the (n+1)th substrate W. This allows for accurate measurement of the substrate W thickness immediately after the change in the tilt of the holding unit 11A. Furthermore, since the measurement value of the measuring unit 18 is corrected based on the data immediately before the change in the tilt of the holding unit 11A, the correction accuracy can be improved. 【0066】 The control circuit 14 pre-stores data in a storage medium regarding the changes in the position where the first and second lifting shafts 192 and 193 contact the respective holding portions 11A of the first and second contacts 181 and 183, as they move up and down. The control circuit 14 corrects the measured value of the measuring unit 18 based on the change data and at least one upward or downward movement of the first and second lifting shafts 192 and 193 between the grinding of the nth substrate W and the grinding of the (n+1)th substrate W. 【0067】 The control circuit 14 may correct the measurement value of the measuring unit 18 during the grinding of the k-th substrate W in accordance with the change in the inclination of the holding unit 11A between the grinding of the n-th substrate W and the grinding of the k-th substrate W. k can be any natural number greater than or equal to (n+1) and is not particularly limited. The control circuit 14 corrects the measurement value of the measuring unit 18 based on the upward or downward movement of at least one of the first lifting axis 192 and the second lifting axis 193 between the grinding of the n-th substrate W and the grinding of the k-th substrate W, and the aforementioned change data. 【0068】An example of the inspection device 40 will be described with reference to Figures 8 and 9. The inspection device 40 includes a first displacement sensor 41, a second displacement sensor 42, and a control circuit 43. The first displacement sensor 41 is positioned above the substrate W held in the chuck 45 and measures the distance from the first displacement sensor 41 to the top surface of the substrate W. The second displacement sensor 42 is positioned below the substrate W held in the chuck 45 and measures the distance from the second displacement sensor 42 to the bottom surface of the substrate W. The first displacement sensor 41 and the second displacement sensor 42 are, for example, confocal sensors. The control circuit 43 measures the thickness of the substrate W based on the measurement results of the first displacement sensor 41 and the second displacement sensor 42. 【0069】 The first displacement sensor 41 and the second displacement sensor 42 are positioned on either side of the substrate W. In this case, the thickness of the substrate W can be measured even if the substrate W does not transmit laser light due to the presence of doped elements. The first displacement sensor 41 and the second displacement sensor 42 are not limited to non-contact types and may be contact types. If the substrate W transmits laser light, it is also possible to measure the thickness of the substrate W by having one displacement sensor receive light reflected from both the upper and lower surfaces of the substrate W. In this case, the inspection device 40 may be incorporated inside the grinding device 10. 【0070】 The chuck 45 has a groove 46 on its holding surface that holds the substrate W, extending from the center to the periphery of the chuck 45. The longitudinal direction of the groove 46 is, for example, the Y-axis direction. As the chuck 45 moves in the Y-axis direction, the second displacement sensor 42 enters and exits the groove 46. When the first displacement sensor 41 and the second displacement sensor 42 measure the thickness of the center of the substrate W, the second displacement sensor 42 enters the groove 46. 【0071】 When the first displacement sensor 41 and the second displacement sensor 42 measure the thickness of the substrate W at a point midway between the center and the periphery, similar to the measurement unit 18 of the grinding device 10, the second displacement sensor 42 extends out of the groove 46. This prevents interference between the second displacement sensor 42 and the chuck 45, while allowing the substrate W to be rotated together with the chuck 45, and enabling the thickness of the substrate W to be measured at multiple points spaced apart in the circumferential direction of the substrate W. In this case, the average of the measured values ​​at multiple points at equal distances from the center of the substrate W is used as a representative value. 【0072】 If the chuck 45 rotates, the chuck 45 is smaller than the substrate W. However, the chuck 45 does not necessarily have to rotate; in that case, the chuck 45 may be larger than the substrate W. If the groove 46 extends from the center to the periphery of the chuck 45, the thickness of the substrate W can be measured at multiple points in the radial direction of the substrate W. 【0073】 The embodiments of the grinding apparatus, grinding method, and program described above have been explained, but this disclosure is not limited to the embodiments described above. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These also naturally fall within the technical scope of this disclosure. 【0074】 This application claims priority based on Japanese Patent Application No. 2024-215176, filed with the Japan Patent Office on December 10, 2024, and the entire contents of Japanese Patent Application No. 2024-215176 are incorporated herein by reference. 【0075】 1 Grinding system 9 Control circuit 10 Grinding device 11A Holding unit 12A Drive unit 18 Measurement unit 19 Adjustment unit W Circuit board

Claims

1. A grinding apparatus comprising: a holding part for holding a substrate; a drive part for pressing a grinding tool against the substrate held by the holding part; a measuring part for measuring the thickness of the substrate during grinding of the substrate; an adjustment part for adjusting the inclination of the holding part with respect to the drive part; and a control circuit, wherein the measuring part has a first contact element that contacts the holding part, a first measuring instrument for measuring the displacement of the first contact element, a second contact element that contacts the substrate held by the holding part, and a second measuring instrument for measuring the displacement of the second contact element, and during grinding of the substrate, the thickness of the substrate is measured based on the relative positions of the first contact element and the second contact element, and the control circuit performs control to correct the measured value of the measuring part in accordance with the change in the inclination of the holding part.

2. The grinding apparatus according to claim 1, wherein the control circuit performs control to correct the measured value of the measuring unit during the grinding of the (n+1)th substrate in accordance with the change in the inclination of the holding unit between the grinding of the nth substrate and the grinding of the (n+1)th substrate.

3. The grinding apparatus according to claim 1, wherein the adjustment unit has a fixing shaft for fixing the holding unit, a first lifting shaft for raising and lowering the holding unit, and a second lifting shaft for raising and lowering the holding unit independently of the first lifting shaft, and the control circuit performs control to correct the measured value of the measuring unit based on the raising or lowering of at least one of the first lifting shaft and the second lifting shaft.

4. The grinding apparatus according to claim 3, wherein the control circuit pre-stores data on the change in the position where the first contactor and the second contactor contact the holding portion, as the first and second lifting shafts move up and down, in a storage medium, and performs control to correct the measured value of the measuring unit based on the upward or downward movement of at least one of the first and second lifting shafts and the change data.

5. The grinding apparatus according to claim 1, wherein the adjustment unit has a fixing shaft for fixing the holding unit, a first lifting shaft for raising and lowering the holding unit, and a second lifting shaft for raising and lowering the holding unit independently of the first lifting shaft, the control circuit stores in advance data on the change in the position where the first contactor and the second contactor contact the holding unit, as a result of the lifting and lowering of the first lifting shaft and the second lifting shaft, and performs control to correct the measured value of the measuring unit based on the raising or lowering of at least one of the first lifting shaft and the second lifting shaft and the change data between the grinding of the nth substrate and the grinding of the (n+1)th substrate.

6. The grinding apparatus according to claim 1, wherein the control circuit performs control to acquire the radial distribution of the thickness of the substrate after grinding the substrate, and control to adjust the inclination based on the radial distribution of the thickness of the substrate after grinding the substrate.

7. The grinding apparatus according to claim 1, wherein the control circuit monitors the corrected measurement value of the measuring unit during grinding of the substrate, and when the corrected measurement value of the measuring unit reaches a set value, it controls the stopping of the approach of the grinding tool to the holding unit.

8. A grinding method comprising grinding the substrate using a grinding apparatus described in any one of claims 1 to 7.

9. A grinding apparatus comprising: a holding part for holding a substrate; a drive unit for pressing a grinding tool against the substrate held by the holding part; a measuring unit for measuring the thickness of the substrate during grinding; an adjustment unit for adjusting the inclination of the holding part with respect to the drive unit; and a computer, wherein the measuring unit comprises: a first contactor that contacts the holding part; a first measuring instrument for measuring the displacement of the first contactor; a second contactor that contacts the substrate held by the holding part; and a second measuring instrument for measuring the displacement of the second contactor, and during grinding the substrate, the thickness of the substrate is measured based on the relative positions of the first and second contactors; and a program that causes the computer of the grinding apparatus to correct the measured value of the measuring unit in accordance with the change in the inclination of the holding part.

10. The program according to claim 9, wherein the computer of the grinding apparatus is instructed to correct the measured value of the measuring unit during the grinding of the (n+1)th substrate in accordance with the change in the inclination of the holding unit between the grinding of the nth substrate and the grinding of the (n+1)th substrate.

11. The adjustment unit comprises a fixing shaft for fixing the holding unit, a first lifting shaft for raising and lowering the holding unit, and a second lifting shaft for raising and lowering the holding unit independently of the first lifting shaft, wherein the program according to claim 9 causes the computer of the grinding apparatus to correct the measurement value of the measuring unit based on the raising or lowering of at least one of the first lifting shaft and the second lifting shaft.

12. The program according to claim 11, which causes the computer of the grinding apparatus to pre-store data on a storage medium the change in the position where the first contactor and the second contactor contact the respective holding portion, as the first and second lifting axes move up and down; and to correct the measured value of the measuring unit based on the upward or downward movement of at least one of the first and second lifting axes and the change data.

13. The adjustment unit comprises a fixing shaft for fixing the holding unit, a first lifting shaft for raising and lowering the holding unit, and a second lifting shaft for raising and lowering the holding unit independently of the first lifting shaft, wherein the computer of the grinding apparatus is instructed to: pre-store data on the change in the contact positions of the first contactor and the second contactor with the holding unit, as a result of the lifting and lowering of the first lifting shaft and the second lifting shaft in a storage medium; and correct the measured value of the measuring unit based on the change data and at least one upward or downward movement of the first lifting shaft and the second lifting shaft between the grinding of the nth substrate and the grinding of the (n+1)th substrate.

14. The program according to claim 9, which causes the computer of the grinding apparatus to perform the following actions: to acquire the radial distribution of the thickness of the substrate after grinding the substrate; and to adjust the slope based on the radial distribution of the thickness of the substrate after grinding the substrate.

15. The program according to claim 9, which causes the computer of the grinding apparatus to monitor the corrected measurement value of the measuring unit while grinding the substrate, and to stop the approach of the grinding tool to the holding unit when the corrected measurement value of the measuring unit reaches a set value.

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