Wafer grinding device

Abstract

The invention discloses a wafer grinding device. And the notch positioning precision is improved. The wafer polishing apparatus includes a positioning unit that includes a positioning table on which a wafer can be mounted, a motor connected to the positioning table, and a camera that captures an image of the wafer. The wafer polishing apparatus has a control system for controlling the motor and the camera. The control system controls the camera to capture a silhouette of the wafer, and controls the motor based on image data of the silhouette.

Description

Technical Field

[0001] The present disclosure relates to a wafer grinding device. Background Art

[0002] When manufacturing semiconductor devices, electronic circuits are formed on wafers such as silicon wafers. In addition, a notch is formed on the outer edge of the wafer, and the notch is subjected to grinding processing (see Patent Document 1). In addition, when grinding the notch of the wafer, a grinding tool such as a grinding disc or a grinding wheel is used.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-137328 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] However, in order to improve the grinding accuracy of the grinding tool on the notch, it is necessary to make the grinding tool contact the notch with good accuracy. In other words, in order to improve the grinding accuracy of the notch, it is important to improve the positioning accuracy of the notch.

[0008] Technical solutions for solving technical problems

[0009] According to the present disclosure, a wafer grinding device has a positioning unit, which has a positioning table capable of carrying a wafer, a motor connected to the positioning table, and a camera for photographing the wafer. The wafer grinding device has a control system for controlling the motor and the camera. The control system controls the camera to photograph a silhouette of the wafer, and controls the motor based on image data of the silhouette.

[0010] Effects of the Invention

[0011] According to the present disclosure, the positioning accuracy of the notch can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram showing a wafer polishing apparatus according to one embodiment of the present disclosure.

[0013] Figure 2 This is a diagram showing an example of a positioning unit constituting a wafer polishing apparatus.

[0014] Figure 3 is from Figure 2 The direction of arrow 3 shows a diagram of the positioning unit and its internal structure.

[0015] Figure 4 FIG. 1 is a diagram showing an example of a polishing unit constituting a wafer polishing apparatus.

[0016] Figure 5 is from Figure 4 The direction of arrow 5 shows the diagram of the grinding unit.

[0017] Figure 6 is from Figure 4 The direction of arrow 6 shows the diagram of the grinding unit.

[0018] Figure 7 is from Figure 4 The direction of arrow 7 shows the grinding unit in the figure.

[0019] Figure 8 This is a diagram showing an example of a control system included in the wafer polishing apparatus.

[0020] Fig. 9 This is a flowchart showing an example of the execution procedure of the notch grinding control.

[0021] Fig.10 This is a flowchart showing an example of the execution procedure of the notch grinding control.

[0022] Fig.11A This is a diagram showing an example of the execution status of the notch grinding control.

[0023] Fig. 11B This is a diagram showing an example of the execution status of the notch grinding control.

[0024] Fig. 12A This is a diagram showing an example of the execution status of the notch grinding control.

[0025] Fig. 12B This is a diagram showing an example of the execution status of the notch grinding control.

[0026] Fig.13A This is a diagram showing an example of image data of a silhouette captured by a camera body.

[0027] Fig. 13B This is a diagram showing an example of image data of a silhouette captured by a camera body.

[0028] Fig. 13C This is a diagram showing an example of image data of a silhouette captured by a camera body.

[0029] Fig.14A This is a diagram showing an example of the positional relationship between the claw portion of the positioning stage and the notch of the wafer.

[0030] Fig. 14B This is a diagram showing an example of the positional relationship between the claw portion of the positioning stage and the notch of the wafer.

[0031] Fig.15AThis is a diagram showing an example of the positional relationship between the reference position and the notch in the image data.

[0032] Fig. 15B This is a diagram showing a state in which the notch is moved to the reference position.

[0033] Fig.16A This is a diagram showing an example of the positional relationship between the reference position and the notch in the image data.

[0034] Fig. 16B This is a diagram showing an example of a situation when the position of the grinding disc is corrected.

[0035] Fig.17 It is a diagram showing a wafer polishing apparatus according to another embodiment.

[0036] Description of Reference Numerals

[0037] 10: wafer; 11: notch; 20: wafer grinding device; 21: positioning unit; 22: grinding unit; 23: grinding disc (grinding tool); 24: conveyor; 32: rotary motor (motor); 33: positioning table; 34: cylinder (actuator); 35: presetting table; 41: table body; 44: camera assembly (camera); 45: camera body (main body); 45a: light guide inlet; 45c: image sensor (camera element); 46: shooting light (light : bright part); 53: lens cover (cover part); 95: disk rotation motor; 96: grinding disk (grinding tool); 103: hand (holding part); 110: control system; 120: wafer grinding device; S11: first step; S16: second step; S17: third step; S19: fourth step; S20: fifth step; S22: sixth step; Pn: reference position; θx: target rotation angle; D1, D2: image data; Δy: position offset. DETAILED DESCRIPTION

[0038] Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. In the following description, the same or substantially the same structures and elements are denoted by the same reference numerals and repeated descriptions are omitted.

[0039] <First Embodiment>

[0040] <Wafer polishing equipment>

[0041] Figure 1 2 is a diagram showing a wafer polishing apparatus 20 according to an embodiment of the present disclosure. Figure 1~Figure 5 , Figure 7 , Fig.15A , Fig.16A as well as Fig. 16B In each of the drawings, the X direction indicated by the arrow X is the direction along the guide rail 65 described later. Figure 1 , Figure 2 , Figure 4 , Figure 6 , Figure 7 , Fig.15A , Fig.16A as well as Fig. 16B In each of the drawings, the Y direction indicated by the arrow Y is a direction along the guide rail 89 described later and is a direction orthogonal to the X direction. Figure 1 to Figure 6 In each of the drawings, the Z direction indicated by the arrow Z is a vertical direction, and is a direction orthogonal to both the X direction and the Y direction.

[0042] like Figure 1 As shown, the wafer grinding device 20 has a positioning unit 21 for positioning the wafer 10, which is the material of the semiconductor device, and a grinding unit 22 for grinding the notch 11 formed in the wafer 10. By using the wafer grinding device 20, the notch 11 of the wafer 10 can be positioned, and the notch 11 can be ground by the grinding disc 23. That is, the positioning unit 21 performs positioning of the wafer 10 (arrow a1), the transfer arm 24 moves the wafer 10 from the positioning unit 21 to the grinding unit 22 (arrow a2), and the grinding unit 22 performs grinding processing of the notch 11 (arrow a3). In addition, as described later Figure 7 As shown in the enlarged part of FIG. 1 , a substantially V-shaped notch 11 is formed at the outer edge 12 of the wafer 10 , and the notch 11 is ground by the grinding disc 23 of the grinding unit 22 .

[0043] <Positioning unit>

[0044] Figure 2 2 is a diagram showing an example of a positioning unit 21 constituting the wafer polishing apparatus 20. Figure 3 is from Figure 2 The arrow 3 in the figure shows the positioning unit 21 and its internal structure. Figure 2 In the range β, the housing 50 and its vicinity that are turned upside down are shown. Figure 2 FIG. 2 shows the positioning unit 21 in which the support table 30 is omitted. Figure 3 2 shows the positioning unit 21 including the support table 30 .

[0045] like Figure 3 As shown, the positioning unit 21 has a unit body 31 mounted on a support table 30. The unit body 31 has a positioning table 33 capable of carrying the wafer 10 and a pre-setting table 35 capable of carrying the wafer 10. The positioning table 33 is connected to a rotary motor (motor) 32, and the pre-setting table 35 is connected to a cylinder 34. The positioning table 33 and the pre-setting table 35 are arranged concentrically, and the center lines of the positioning table 33 and the pre-setting table 35 are consistent with each other. Figure 2 as well as Figure 3 As shown, the positioning table 33 includes an annular table body 37 connected to the table rotating motor 32 via a rotating shaft 36, and a plurality of claws 38 attached to the outer periphery of the table body 37. By driving the table rotating motor 32, the positioning table 33 can be rotated about the center line C1 as the rotation center.

[0046] The presetting table 35 has a substantially triangular table body 41 connected to the cylinder (actuator) 34 via a guide rod 40, and a plurality of support arms 42 extending upward from the table body 41. A claw 43 is attached to the front end of the support arm 42. Figure 3 As shown by arrow Za1, the presetting table 35 can be moved downward toward the retreat position Pa1 by contracting the piston rod 34a of the air cylinder 34. By moving the presetting table 35 to the retreat position Pa1, the claw 43 of the presetting table 35 is arranged at a position lower than the claw 38 of the positioning table 33. On the other hand, as shown by arrow Za2, the presetting table 35 can be moved upward toward the protruding position Pa2 by extending the piston rod 34a of the air cylinder 34. By moving the presetting table 35 to the protruding position Pa2, the claw 43 of the presetting table 35 is arranged at a position higher than the claw 38 of the positioning table 33.

[0047] In the example shown in the figure, the cylinder 34 is used to move the presetting table 35 up and down, but the present invention is not limited to this, and the cylinder 34 can also be used to move the positioning table 33 up and down. In other words, the positioning unit 21 only needs to have a mechanism that can relatively raise the presetting table 35 relative to the positioning table 33 and can relatively lower the presetting table 35 relative to the positioning table 33. That is, even in the case where the positioning table 33 is moved upward by the cylinder 34, that is, in the case where the presetting table 35 is relatively lowered relative to the positioning table 33, the positioning unit 21 can be operated in the same manner as when the presetting table 35 is moved to the retreat position Pa1. In addition, even in the case where the positioning table 33 is moved downward by the cylinder 34, that is, in the case where the presetting table 35 is relatively raised relative to the positioning table 33, the positioning unit 21 can be operated in the same manner as when the presetting table 35 is moved to the protruding position Pa2.

[0048] like Figure 3As shown, a camera unit (camera) 44 composed of a camera body (main body) 45 and a shooting light (illumination unit) 46 is installed on the unit body 31 of the positioning unit 21. The shooting light 46 is installed on the base member 47 mounted on the unit body 31, and the shooting light 46 is located at a position lower than the table body 37 of the positioning table 33. In addition, a housing 50 is installed on the base member 47 via a support 48 and a bracket 49. The camera body 45 is accommodated in the housing 50, and the camera body 45 is located at a position higher than the table body 37 of the positioning table 33. In addition, the camera body 45 and the shooting light 46 are arranged to face each other. Furthermore, the camera body 45 includes a light introduction port 45a, a lens 45b, and an image sensor (shooting element) 45c. As the image sensor 45c, for example, a CMOS image sensor or a CCD image sensor can be used. In addition, as will be described later, by placing the wafer 10 on the positioning stage 33 and lighting the imaging light 46 , it is possible to image a silhouette of the wafer 10 using the camera body 45 .

[0049] In addition, a rotary actuator 51 for extending and rotating an output rod 51a is mounted on the bracket 49 that holds the housing 50. A lens cover (cover member) 53 is mounted on the output rod 51a of the rotary actuator 51 via a swing arm 52. By driving the rotary actuator 51, the output rod 51a of the rotary actuator 51 can be rotated as shown in FIG. Figure 2 as well as Figure 3 The lens cover 53 is moved in the manner indicated by the arrow α. Figure 3 As shown, the lens cover 53 can be moved to a closed position Pb1 for shielding the light inlet 45a of the camera body 45 and an open position Pb2 for exposing the light inlet 45a of the camera body 45. In addition, the illustrated rotary actuator 51 is an actuator driven by a motor, but is not limited thereto, and may be an actuator driven by air pressure, for example.

[0050] <Grinding Unit>

[0051] Figure 4 FIG. 2 is a diagram showing an example of the polishing unit 22 constituting the wafer polishing apparatus 20 . Figure 5 is from Figure 4 The direction of arrow 5 shows the grinding unit 22, Figure 6 is from Figure 4 The direction of arrow 6 shows the grinding unit 22, Figure 7 is from Figure 4 The direction of arrow 7 shows the grinding unit 22. Figure 4 as well as Figure 7 FIG. 2 shows the polishing unit 22 in which the support tables 62, 86 and the conveying hand 24 are omitted. Figure 5 as well as Figure 6 2 shows the polishing unit 22 including the support tables 62 and 86 and the transport hand 24 .

[0052] like Figure 4 As shown, the grinding unit 22 has a table driving section 60 for driving the grinding table 74 and a disk driving section 61 for driving the grinding disk 23. Figure 5 as well as Figure 6 As shown in FIG. 1 , the stage driving unit 60 includes a column 64 disposed inside an opening 63 formed in a support table 62. A guide rail 65 extending in the X direction is mounted on the upper surface of the support table 62, and a slider 66 is mounted on the column 64. The slider 66 is mounted to be movable relative to the guide rail 65, and the column 64 is movable relative to the support table 62 in the X direction. In addition, a nozzle 67 for supplying a polishing liquid is mounted on the column 64 of the stage driving unit 60.

[0053] like Figure 4~Figure 7 As shown, the column 64 of the table driving unit 60 has a tilting mechanism 70 for tilting the grinding table 74. Figure 5 as well as Figure 6 As shown, the tilt mechanism 70 includes a table tilt motor 71 mounted on the lower portion of the column 64, a swing arm 72 swingably mounted on the upper portion of the column 64, and a drive belt 73 connecting the table tilt motor 71 and the swing arm 72. In addition, a polishing table 74 capable of carrying a wafer 10 is mounted on the swing arm 72 of the tilt mechanism 70. The tilt mechanism 70 can tilt the polishing table 74 up and down with the center line C2 as the rotation center by rotating the table tilt motor 71 at a predetermined angle to swing the swing arm 72.

[0054] like Figure 7 As shown in FIG. 1 , the table driving unit 60 includes a holding claw 75a fixed to the table body 75 of the grinding table 74, and a holding claw 75b movably mounted on the table body 75. In addition, the table body 75 includes a cylinder 76 connected to the holding claw 75b. As shown by the arrow Xa1, by extending the piston rod 76a of the cylinder 76, the holding claw 75b can be moved to a release position away from the holding claw 75a. On the other hand, as shown by the arrow Xa2, by contracting the piston rod 76a of the cylinder 76, the holding claw 75b can be moved to a holding position close to the holding claw 75a. In addition, in a state where the wafer 10 is transported to the grinding table 74, by contracting the cylinder 76, the holding claw 75b is moved to the holding position, and the wafer 10 can be held or clamped by the grinding table 74. On the other hand, by extending the cylinder 76, the holding claw 75b is moved to the release position, and the clamping of the wafer 10 by the grinding table 74 can be released.

[0055] like Figure 5 as well as Figure 6As shown, a threaded shaft 80 extending in the X direction is mounted on the lower surface of the support table 62, and the threaded shaft 80 is driven to rotate by an X-axis motor 81. A nut 82 constituting a ball screw is mounted on the threaded shaft 80, and a cylinder body 84a of a cylinder 84 is mounted on the nut 82 via a bracket 83. In addition, a bracket 85 having a through hole is mounted on the lower part of the column 64, and a cylinder body 84a of the cylinder 84 is mounted on the bracket 85. Furthermore, a piston rod 84b of the cylinder 84 is inserted into the through hole of the bracket 85, and the piston rod 84b abuts against the lower part of the column 64.

[0056] The disk drive section 61 constituting the grinding unit 22 has a column 88 disposed inside an opening 87 formed in a support table 86. A guide rail 89 extending in the Y direction is mounted on the upper surface of the support table 86, and a slider 91 is mounted on a base plate 90 of the column 88. The slider 91 is mounted so as to be movable relative to the guide rail 89, and the column 88 is movable relative to the support table 86 in the Y direction. In addition, a threaded shaft 92 extending in the Y direction is disposed above the base plate 90, and the threaded shaft 92 is rotationally driven by a Y-axis motor 93 mounted on the support table 86. A nut 94 constituting a ball screw is mounted on the threaded shaft 92, and the nut 94 is mounted on the base plate 90. The column 88 of the disk drive section 61 can be moved in the Y direction by rotationally driving the Y-axis motor 93.

[0057] In addition, a disk rotating motor 95 is installed on the upper part of the column 88, and a rotating shaft 97 supporting two grinding disks (grinding tools) 23 and 96 is installed on the lower part of the column 88. The disk rotating motor 95 and the rotating shaft 97 are connected via a drive belt 98, and the grinding disks 23 and 96 can be rotated by the disk rotating motor 95. Figure 6 In the example shown, since the grinding disc 23 is opposite to the notch 11 of the wafer 10, the notch 11 can be ground using the grinding disc 23. In addition, when the grinding disc 23 is worn, the grinding disc 96 can be made to face the notch 11 of the wafer 10 by driving the Y-axis motor 93 to move the column 88 in the direction of the arrow Ya1. In this way, by making the grinding disc 96 face the notch 11, the notch 11 can be ground using the grinding disc 96. In addition, the grinding discs 23 and 96 that can grind the notch 11 can be formed using non-woven fabric or the like.

[0058] like Figure 5As shown, the column 64 of the table driving unit 60 can move to a grinding position Pc1 for grinding the wafer 10 held on the grinding table 74, and a preparation position Pc2 for detaching the wafer 10 from the grinding table 74. That is, by driving the X-axis motor 81 to move the bracket 83 in the direction of the arrow Xb1, the column 64 of the table driving unit 60 can be moved to the grinding position Pc1, and the grinding table 74 can be brought closer to the grinding disk 23. In addition, by driving the X-axis motor 81 to move the bracket 83 in the direction of the arrow Xb2, the column 64 of the table driving unit 60 can be moved to the grinding position Pc2, and the grinding table 74 can be moved away from the grinding disk 23. In addition, in Figure 4 , Figure 6 as well as Figure 7 , the column 64 and the polishing table 74 are shown moving to the polishing position Pc1.

[0059] As described above, by moving the column 64 of the stage driving unit 60 to the polishing position Pc1, the polishing disc 23 can be brought into contact with the notch 11 of the wafer 10, and the notch 11 of the wafer 10 can be polished by the rotating polishing disc 23. Figure 5 As shown, a cylinder 84 is installed between the brackets 83 and 85, and the lower part of the column 64 is urged in the direction of the arrow Xb1 with a predetermined thrust by the cylinder 84. Thus, when the wafer 10 is ground by the grinding disc 23, the pressing load of the grinding disc 23 on the wafer 10 can be controlled by controlling the thrust of the cylinder 84.

[0060] <Transport Hand>

[0061] like Figure 1 , Figure 5 as well as Figure 6 As shown, the wafer polishing device 20 has a transfer hand 24 that can move in the X direction, the Y direction, and the Z direction. By using the transfer hand 24 that can hold the wafer 10, the wafer 10 can be moved from the positioning table 33 to the polishing table 74, and the wafer 10 can be moved from the polishing table 74 to a table for the next process (not shown). In addition, as described later Fig.11A As shown, the wafer polishing apparatus 20 includes a transfer hand 100 having the same mechanism as the transfer hand 24 in order to move the wafer 10 from a stage in a previous process (not shown) to the positioning stage 33 .

[0062] The transport hand 24, 100 has a hand (holding part) 103 composed of a pair of sliding plates 101, 102. The sliding plate 101 has two holders 101a, and the sliding plate 102 has two holders 102a. By bringing the sliding plates 101, 102 closer to each other, the outer edge 12 of the wafer 10 can be clamped by the holders 101a, 102a. On the other hand, by moving the sliding plates 101, 102 away from each other, the wafer 10 can be released from the holders 101a, 102a. In addition, in order to move the sliding plates 101, 102, the transport hand 24, 100 is provided with a motor and a cylinder (not shown).

[0063] <Control System>

[0064] Figure 8 1 is a diagram showing an example of a control system 110 provided in the wafer polishing apparatus 20. Figure 8 As shown, in order to control the positioning unit 21, the grinding unit 22, and the conveying hand 24, 100, the wafer grinding device 20 has a control system 110 composed of a plurality of control units 111 to 114 connected to each device in a communicative manner. The control units 111 to 114 are connected to each other in a communicative manner via a wired or wireless communication network 115. In addition, the control units 111 to 114 have microcontrollers 111a to 114a assembled with a processor and a main memory. A predetermined program is stored in the main memory, and an instruction set of the program is executed by the processor.

[0065] The control units 111 to 114 include drive circuits 111 b to 114 b and the like that output control signals to various components such as motors. That is, the control unit 111 outputs control signals to the table rotation motor 32, the camera assembly 44, the rotation actuator 51, and the air supply unit 116 and the like in order to control the positioning unit 21. In addition, the control unit 112 outputs control signals to the X-axis motor 81, the table tilt motor 71, the Y-axis motor 93, the disk rotation motor 95, the air supply unit 117, and the polishing liquid supply unit 118 and the like in order to control the polishing unit 22. In addition, the control unit 113 outputs control signals to the motor and the like provided in the transport hand 24, and the control unit 114 outputs control signals to the motor and the like provided in the transport hand 100. In addition, as the table rotation motor 32, the X-axis motor 81, the table tilt motor 71, and the Y-axis motor 93, servo motors can be used.

[0066] The air supply unit 116 is composed of a control valve (not shown) connected to the cylinder 34. By using the air supply unit 116 to control the air pressure supplied to the cylinder 34, the extension direction and thrust of the piston rod 34a can be controlled. In addition, the air supply unit 117 is composed of a control valve (not shown) connected to the cylinder 84. By using the air supply unit 117 to control the air pressure supplied to the cylinder 84, the thrust of the piston rod 84b can be controlled. Further, the polishing liquid supply unit 118 is composed of a control valve (not shown) connected to the nozzle 67 and a pump. By using the polishing liquid supply unit 118 to control the supply amount of the polishing liquid, the supply state of the polishing liquid can be controlled.

[0067] <Notch grinding control>

[0068] Next, the execution procedure of the notch grinding control by the control system 110 will be described. Fig. 9 as well as Fig.10 This is a flowchart showing an example of the execution procedure of the notch grinding control. Fig. 9 as well as Fig.10 The flow charts shown are connected to each other at reference numeral A. In addition, Fig.11A , Fig. 11B , Fig. 12A as well as Fig. 12B This is a diagram showing an example of the execution status of the notch grinding control.

[0069] like Fig. 9 As shown, the control system 110 enters step S10, and controls the conveyor 24 to move the wafer 10 toward the positioning table 33. In addition, the control system 110 enters step S11 (first step), and controls the camera body 45 to capture the silhouette of the wafer 10 at a predetermined rotation angle while controlling the table rotation motor 32 to rotate the positioning table 33. In other words, Fig.11A As shown, the control system 110 moves the wafer 10 toward the positioning table 33 (arrow α1) through the conveying hand 100. Fig. 11B As shown in FIG. 1 , the wafer 10 is mounted on the positioning table 33. Fig. 11B As shown, the control system 110 rotates the positioning stage 33 (arrow α2) and captures a silhouette (reference numeral α3) of a predetermined range through the camera body 45. Fig.13A , Fig. 13B as well as Fig. 13C 4 is a diagram showing an example of image data of a silhouette captured by the camera body 45. Figure 13A to Figure 13C As shown, the contour of the outer edge portion 12 of the wafer 10 is captured at a predetermined rotation angle.

[0070] Thus, the control system 100 controls the camera assembly 44 to capture the silhouette of the wafer 10 while controlling the table rotation motor 32 to change the rotation angle of the positioning table 33 in step S11. In addition, in step S11, the control system 100 rotates the positioning table 33 at least more than one rotation (360°) in order to capture the outer edge 12 of the wafer 10 over the entire circumference. Furthermore, in step S11, in order to capture the entire outer edge 12 of the wafer 10, the shooting interval of the camera body 45, that is, the rotation angle of the shooting, is determined based on the viewing angle. In addition, in order to protect the camera body 45 from the influence of the scattered polishing liquid, etc., the control system 110 moves the lens cover 53 to the open position Pb2 when starting step S11, and moves the lens cover 53 to the closed position Pb1 when ending step S11.

[0071] Next, the process proceeds to step S12, where the control system 110 performs filtering processing such as edge detection on the plurality of image data obtained in step S11, and determines whether any of the image data includes the gap 11. When the control system 110 determines in step S12 that none of the image data includes the gap 11, the process proceeds to step S13. Fig.14A as well as Fig. 14B 1 is a diagram showing an example of the positional relationship between the claw portion 38 of the positioning stage 33 and the notch 11 of the wafer 10. Fig.14A As shown in FIG. 1 , when the claw portion 38 and the notch 11 are far away from each other, image data including the silhouette of the notch 11 can be obtained. Fig. 14B As shown, when the claw 38 and the notch 11 overlap each other, image data including the silhouette of the notch 11 cannot be obtained. In addition, when the notch 11 overlaps the claw 43 of the preset stage 35, image data including the silhouette of the notch 11 cannot be obtained.

[0072] That is, all the image data obtained in step S11 are as described above. Fig. 13B as well as Fig. 13C In the case of image data such as that shown in FIG. 1 , in step S12, it is determined that the image data does not include the notch 11. When the control system 110 determines in step S12 that the image data does not include the notch 11, the control system 110 proceeds to step S13 to raise the pre-positioning table 35, proceeds to step S14 to rotate the positioning table 33 at a predetermined angle, and proceeds to step S15 to lower the pre-positioning table 35.

[0073] That is, the control system 110 controls the cylinder 34 to raise the pre-positioning table 35, and the control station rotation motor 32 rotates the positioning table 33 at a predetermined angle while the wafer 10 is moved from the positioning table 33 to the pre-positioning table 35. In addition, after rotating the positioning table 33 at a predetermined angle, the control system 110 controls the cylinder 34 to lower the pre-positioning table 35, so that the wafer 10 is moved from the pre-positioning table 35 to the positioning table 33. In this way, when the placement position of the positioning table 33 with respect to the wafer 10 is changed and the overlap between the notch 11 and the claws 38 and 43 is eliminated, step S11 is entered again to capture the silhouette of the wafer 10. In addition, in order to make the notch 11 away from the claws 38 and 43, the predetermined angle when the positioning table 33 is rotated is predetermined in advance based on the width size of the claws 38 and 43, the setting interval, etc.

[0074] When the control system 110 determines in step S12 that the image data includes the notch 11, the process proceeds to step (second step) S16, and calculates the target rotation angle θx of the positioning stage 33 required to move the notch 11 to the reference position Pn based on the image data. For example, the control system 110 can calculate the target rotation angle θx of the positioning stage 33 in the following order. Fig.15A as well as Fig. 15B As shown, the reference position Pn of the notch 11 is the position where the center Cn of the notch 11 (hereinafter referred to as notch center Cn) overlaps the reference plane PL1. The reference plane PL1 is a plane that includes the center line C1 of the positioning stage 33 and is aligned with or parallel to the X direction.

[0075] Fig.15A 1 is a diagram showing an example of the positional relationship between the reference position Pn and the notch 11 in the image data D1. Fig. 15B 1 is a diagram showing a state in which the notch 11 is moved to the reference position Pn. Fig.15A As shown, the control system 110 extracts the image data D1 including the notch 11, and obtains the rotation angle θ1 of the positioning stage 33 that captured the image data D1. Next, the control system 110 calculates the virtual plane PL2 including the notch center Cn and the center line C1, and calculates the angle θ2 formed by the reference plane PL1 and the virtual plane PL2. Then, the control system 110 subtracts the angle θ2 from the rotation angle θ1 of the positioning stage 33, and calculates the target rotation angle θx of the positioning stage 33 (θx=θ1-θ2). In addition, in the present embodiment, regarding the rotation angle of the positioning stage 33, clockwise is defined as a positive value, and counterclockwise is defined as a negative value.

[0076] When the control system 110 calculates the target rotation angle θx in step S16, the process proceeds to step (third step) S17 to rotate the positioning stage 33 based on the target rotation angle θx. Fig. 15BAs shown, the notch 11 is moved to the reference position Pn, that is, the notch center Cn and the reference position Pn overlap each other. In this way, the control system 110 calculates the target rotation angle θx of the positioning stage 33 based on the image data captured by the camera body 45, and controls the table rotation motor 32 to rotate the positioning stage 33 based on the target rotation angle θx. That is, the control system 110 controls the camera assembly 44 to capture the silhouette of the wafer 10, and controls the rotation motor 32 based on the image data of the silhouette. As a result, the positioning accuracy of the notch 11 can be greatly improved.

[0077] When the control system 110 rotates the positioning stage 33 based on the target rotation angle θx in step S17, as shown in FIG. Fig.10 As shown, the process proceeds to step S18. In step S18, the control system 110 clamps the wafer 10 on the positioning table 33 through the conveying hand 24, and proceeds to step (the fourth step) S19 to capture the silhouette of the wafer 10 clamped by the conveying hand 24. In other words, Fig. 11B As shown, the control system 110 moves the conveying hand 24 toward the positioning table 33 (arrow α4), as shown in FIG. Fig. 12A As shown, a silhouette (reference numeral α5) of a predetermined range is captured while the wafer 10 on the positioning stage 33 is clamped. In order to protect the camera body 45 from the influence of the scattered polishing liquid, etc., the control system 110 moves the lens cover 53 to the open position Pb2 when starting step S19, and moves the lens cover 53 to the closed position Pb1 when ending step S19.

[0078] Next, the control system 110 enters step (fifth step) S20, performs filtering processing such as edge detection on the image data obtained in step S19, and calculates the position deviation Δy of the notch 11 relative to the reference position Pn. That is, in the above-mentioned step S17, the notch 11 is moved to the reference position Pn, but when the wafer 10 is clamped by the transfer hand 24, the notch 11 may slightly deviate from the reference position Pn. Therefore, the control system 110 calculates the position deviation Δy of the notch 11 relative to the reference position Pn in step S20.

[0079] When the control system 110 calculates the positional offset Δy of the notch 11 in step S20, the process proceeds to step S21, and the wafer 10 is moved from the positioning table 33 to the grinding table 74 by the conveying hand 24. Next, the process proceeds to step (sixth step) S22, and the control system 110 controls the Y-axis motor 93 based on the positional offset Δy, thereby correcting the position of the column 64, that is, the grinding disc 23. Then, the process proceeds to step S23, and the control system 110 rotates the grinding disc 23 and moves the grinding table 74, and grinds the notch 11 of the wafer 10 by the grinding disc 23. In addition, in step S23, in order to properly grind the inclined surface and chamfered surface of the notch 11, the notch is ground while the grinding disc 74 is tilted. In addition, when the control system 110 completes the notch grinding in step S23, the process proceeds to step S24, and the wafer 10 is moved from the grinding table 74 to the table of the next process by the conveying hand (not shown).

[0080] That is to say, Fig. 12A As shown, the control system 110 moves the wafer 10 from the positioning table 33 toward the grinding table 74 (arrow α6) through the conveying hand 24. Fig. 12B As shown, the position of the grinding disc 23 is corrected based on the position offset Δy (arrow α7). Then, the control system 110 rotates the grinding disc 23 (arrow α8) and moves the grinding table 74 (arrow α9). As a result, the notch 11 can be brought into contact with the grinding disc 23 with good accuracy, and the notch 11 can be ground with high accuracy by the grinding disc 23.

[0081] Fig.16A 1 is a diagram showing an example of the positional relationship between the reference position Pn and the notch 11 in the image data D2. Fig. 16B 2 is a diagram showing an example of a situation when the position of the grinding disc 23 is corrected. Fig.16A As shown, the control system 110 calculates a virtual plane PL3 including the notch center Cn and parallel to the reference plane PL1 based on the image data D2 obtained in step S19, and calculates the interval Δy between the reference plane PL1 and the virtual plane PL3. The interval Δy is the difference between the reference position Pn and the notch center Cn in the Y direction, which is the position offset Δy mentioned above. Then, as Fig. 16B As shown, the control system 110 moves the column 64 of the disk drive 61, that is, the grinding disk 23, by the same amount of movement as the positional deviation amount Δy in the direction of arrow Yb1.

[0082] Since the conveying hand 24 does not rotate the wafer 10, the wafer 10 can be moved from the positioning table 33 to the grinding table 74 while maintaining the positioning accuracy of the positioning table 33. However, since the conveying hand 24 is a structure that clamps the wafer 10 by clamping the holders 101a and 102a, it is possible that the wafer 10 is slightly offset when clamping the wafer 10. Therefore, the control system 110 calculates the position offset Δy based on the image data D2 obtained by step S19, and corrects the position of the grinding disk 23 based on the position offset Δy. Thus, when the conveying hand 24 holds the wafer 10, even if the notch center Cn deviates from the reference position Pn, the grinding disk 23 can be properly opposed to the notch 11, and the grinding accuracy of the notch 11 can be improved.

[0083] <Second Embodiment>

[0084] exist Figure 1 In the example shown, after the wafer 10 is positioned on the positioning table 33, the wafer grinding device 20 moves the wafer 10 from the positioning table 33 to the grinding table 74, and grinds the notch 11 of the wafer 10 on the grinding table 74, but the present invention is not limited thereto. That is, the notch 11 of the wafer 10 may be grinded while the positioning table 33 is always mounted on the positioning table 33 by making the positioning table 33 function as the grinding table 74.

[0085] Fig.17 FIG. 2 is a diagram showing a wafer polishing apparatus 20 according to another embodiment. Fig.17 In, with Figure 1 The same parts and locations as those shown in the figure are marked with the same reference numerals and their descriptions are omitted. Fig.17 As shown, the wafer polishing apparatus 20 includes a positioning unit 21 for positioning the wafer 10, and a disk drive 61 for driving the polishing disks 23 and 96. The disk drive 61 is also equipped with a mechanism for moving the disk in the Y direction.

[0086] After positioning the wafer 10 using the positioning unit 21, the wafer grinding device 120 can grind the wafer 10 mounted on the positioning table 33. Thus, since the wafer 10 is not moved after positioning is completed, the grinding disc 23 and the notch 11 can be placed oppositely with high precision, and the grinding precision of the grinding disc 23 on the notch 11 can be improved.

[0087] <Other Implementation Methods>

[0088] Of course, the present disclosure is not limited to the above-mentioned embodiments, and various changes can be made without departing from the scope of the main purpose. For example, in the above description, the column 64 of the disk drive unit 61, that is, the grinding disk 23, is moved based on the position offset Δy, but it is not limited to this. The column 64 of the table drive unit 60, that is, the grinding table 74, can also be moved based on the position offset Δy. In this case, of course, the mechanism for moving in the Y direction is assembled in the table drive unit 60. In addition, in the above description, the grinding disks 23 and 96 are used as grinding tools, but it is not limited to this. A roughly cylindrical grinding wheel can also be used as a grinding tool, and a grinding belt can also be used as a grinding tool.

[0089] In the above description, the control system 110 is constituted by a plurality of control units 111 to 114, but the present invention is not limited thereto, and the control system 110 may be constituted by a single control unit. In addition, in the example shown in the figure, the wafer 10 is placed on the claws 38 of the positioning table 33, but the present invention is not limited thereto, and the wafer 10 may be clamped by the positioning table 33, or the positioning table 33 may adsorb the wafer 10. In addition, in the example shown in the figure, the wafer 10 is clamped by the holding claws 75a and 75b of the grinding table 74, but the present invention is not limited thereto, and the grinding table 74 may adsorb the wafer 10.

[0090] In the above description, when photographing the silhouette of the wafer 10, the positioning stage 33 is rotated in a manner exceeding one rotation (360°), but the present invention is not limited thereto. Fig.13A As shown in FIG. 1 , the rotation of the positioning stage 33 may be stopped when the image data including the silhouette of the notch 11 is obtained. In addition, in the above description, in step S16, the angle θ2 formed by the reference plane PL1 and the virtual plane PL2 is calculated, and the target rotation angle θx of the positioning stage 33 is calculated using the angle θ2, but the present invention is not limited to this. For example, when the image data including the silhouette of the notch 11 is obtained, the rotation of the positioning stage 33 may be stopped. Fig.15A In the case of the image data shown, the positional offset between the notch center Cn and the reference position Pn in the Y direction can also be calculated, and the target rotation angle θx of the positioning stage 33 can be calculated based on the positional offset. Furthermore, since the wafer polishing device 20, 120 can capture the silhouette of the notch 11 through the camera body 45, it is possible not only to locate the notch 11 but also to manage the polished shape of the notch 11. That is, after the notch 11 is polished by the polishing disc 23, the silhouette of the notch 11 is captured again, so that the polished shape of the notch 11 can be managed for each wafer.

Claims

1. A wafer grinding device for positioning a notch of a wafer for grinding, the wafer grinding device comprising: a positioning unit including a positioning stage capable of mounting the wafer, a motor connected to the positioning stage, and a camera for photographing the wafer mounted on the positioning stage; and a control system connected to the positioning unit in a communicable manner and controlling the motor and the camera, The control system controlling the camera to capture a silhouette of the wafer, The motor is controlled based on the image data of the silhouette.

2. The wafer grinding apparatus according to claim 1, wherein: The control system performs: The first step is to control the motor to change the rotation angle of the positioning table while controlling the camera to shoot a silhouette of the wafer; The second step is to calculate the target rotation angle of the positioning stage required to move the notch to a reference position based on the image data of the silhouette; as well as In a third step, the motor is controlled based on the target rotation angle to rotate the positioning table so as to move the notch to the reference position.

3. The wafer grinding apparatus according to claim 2, wherein: The positioning unit has: A presetting table, comprising a table body located below the positioning table and a plurality of support arms extending upward from the table body; as well as an actuator, mounted on the positioning table or the presetting table, to move the positioning table or the presetting table up and down, When the image data of the silhouette obtained by the first step does not include the gap, the control system The actuator is controlled to raise the presetting table relative to the positioning table, and the motor is controlled to rotate the positioning table at a predetermined angle while the wafer is moved from the positioning table to the presetting table. After the positioning stage is rotated at the predetermined angle, the actuator is controlled to lower the pre-setting stage relative to the positioning stage, and the first step is performed again in a state where the wafer is moved from the pre-setting stage to the positioning stage.

4. The wafer grinding apparatus according to claim 1, wherein: The wafer grinding device comprises: a grinding unit, comprising a grinding table capable of carrying the wafer and a grinding tool capable of grinding the notch; and The transfer hand includes a holding portion capable of holding the wafer, and the transfer hand transfers the wafer from the positioning table to the polishing table.

5. The wafer grinding apparatus according to claim 2, wherein: The wafer grinding device comprises: a grinding unit, comprising a grinding table capable of carrying the wafer and a grinding tool capable of grinding the notch; and A transfer hand includes a holding portion capable of holding the wafer, and the transfer hand transfers the wafer from the positioning table to the polishing table. After executing the third step, the control system executes a fourth step of controlling the camera to capture a silhouette of the wafer while the wafer mounted on the positioning table is held on the transfer arm. After executing the fourth step, executing a fifth step of calculating the positional offset between the notch and the reference position based on the image data of the silhouette obtained in the fourth step, After the fifth step is performed, a sixth step of moving the grinding tool or the grinding table based on the positional offset is performed.

6. The wafer grinding apparatus according to claim 1, wherein: The camera includes a main body and an illumination unit. The main body includes an imaging element. The illumination unit is arranged to face the main body.

7. The wafer grinding apparatus according to claim 1, wherein: The camera includes a cover member that moves between a closed position that shields a light introduction port and an open position that exposes the light introduction port.

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