Conveying mechanism and method for setting a conveying mechanism

Abstract

Provided is a conveyance mechanism and a setting method for the conveyance mechanism, which easily sets the conveyance mechanism even if a workpiece has a quadrangular shape, a circular shape, or another shape. The conveyance mechanism includes: a convey-out unit that conveys out a workpiece from a cassette; a photographing unit that photographs and stores a state of the workpiece conveyed out to a prescribed position; a correction unit that corrects the state of the workpiece; and a conveyance unit that places the corrected workpiece at a desired position of a chuck table. The setting method includes: a placement process of placing the workpiece at the desired position of the chuck table; a reverse conveyance process of reversely conveying the workpiece to the prescribed position; a reference image storage process of photographing the state of the workpiece and storing the photographed state of the workpiece as a reference image; a correction process of photographing the state of the workpiece and correcting the state of the workpiece in a manner consistent with the reference image; and a holding process of conveying and holding the corrected workpiece at the chuck table.

Description

Technical Field

[0001] The present invention relates to a conveying mechanism for transferring workpieces to a chuck table and a method for setting up the conveying mechanism. Background Technology

[0002] A workpiece (such as a semiconductor wafer) with multiple devices such as ICs and LSIs formed on its front side by dividing it by a predetermined dividing line is processed to the desired thickness by grinding the back side with a grinding device, and then divided into individual device chips by a cutting device for use in electronic devices such as mobile phones and personal computers.

[0003] The grinding apparatus generally includes: a cassette for storing multiple wafers; a transfer unit for removing wafers from the cassette; a temporary placement stage for temporarily placing and aligning the removed wafers; a transport unit for transporting the wafers from the temporary placement stage to a chuck stage; and a grinding unit for grinding the wafers transported to the chuck stage. The grinding apparatus is capable of processing wafers to a desired thickness (see, for example, Patent Document 1).

[0004] In addition, the wafer temporarily placed on the temporary worktable of the grinding device is moved towards the center by multiple pins provided on the temporary worktable to contact the outer periphery of the wafer and position the center of the wafer at the center of the temporary worktable, thereby achieving alignment. The holding part constituting the transfer unit is set to move from the center of the temporary worktable to the center of the chuck worktable.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-003611

[0006] However, when the wafer is transported to the chuck stage and placed in the required position by the aforementioned transport unit, it must be carried out with a precision of less than 1 mm. Especially when the workpiece is quadrilateral, it is difficult to perform the alignment based on the center of multiple pins as described above, and it is necessary to transport it to the required position on the chuck stage with accurate positioning in the direction of each side. The setting of the transport mechanism is extremely troublesome. Summary of the Invention

[0007] The present invention was made in view of the above facts, and its main technical problem is to provide a conveying mechanism and a method for setting the conveying mechanism that are easy to set even if the shape of the workpiece is quadrilateral, circular or other shapes.

[0008] To address the aforementioned major technical challenges, the present invention provides a conveying mechanism for conveying a workpiece to a chuck table. The conveying mechanism comprises: a removal unit for removing a workpiece from a chuck table; a photographing unit for photographing and storing the state of the workpiece after it has been moved to a predetermined position by the removal unit; a correction unit for correcting the state of the workpiece photographed by the photographing unit; and a conveying unit for conveying the corrected workpiece to the chuck table and placing it at a desired position on the chuck table.

[0009] Preferably, the conveying mechanism corresponds to the shape of circular and quadrilateral workpieces.

[0010] According to the present invention, a method for setting a conveying mechanism is provided, the method comprising the following steps: a loading step, wherein a workpiece is loaded onto a desired position on the chuck table; a reverse conveying step, wherein the workpiece loaded on the chuck table is reverse conveyed to the predetermined position by a conveying unit; and a reference image storage step, wherein the state of the workpiece reverse conveyed to the predetermined position is captured by an imaging unit, and the captured state of the workpiece is stored as a reference image. The method for setting the conveying mechanism is configured to include the following steps: a correction step, wherein the state of the workpiece is captured by an imaging unit and moved from the cassette to the predetermined position by a move-out unit, and the state of the workpiece is corrected by a correction unit in a manner consistent with the reference image; and a holding step, wherein the corrected workpiece is conveyed by the conveying unit and held on the chuck table.

[0011] The conveying mechanism of the present invention is a conveying mechanism for conveying workpieces to a chuck worktable. The conveying mechanism is configured to include: a removal unit that removes a workpiece from a chuck support placed on a chuck worktable; a photographing unit that photographs and stores the state of the workpiece moved to a predetermined position by the removal unit; a correction unit that corrects the state of the workpiece photographed by the photographing unit; and a conveying unit that conveys the corrected workpiece to the chuck worktable and places it at the desired position on the chuck worktable. Therefore, even if the workpiece is quadrilateral, circular, or other shaped, the conveying mechanism is easy to set up, eliminating cumbersome problems.

[0012] Furthermore, the method for setting up the conveying mechanism of the present invention includes the following steps: a loading step, in which a workpiece is loaded at a desired position on a chuck table; a reverse conveying step, in which the workpiece loaded on the chuck table is reverse conveyed to a predetermined position by a conveying unit; and a reference image storage step, in which the state of the workpiece reverse conveyed to the predetermined position is photographed by an imaging unit, and the photographed state of the workpiece is stored as a reference image. The method for setting up the conveying mechanism is configured to include the following steps: a correction step, in which the state of the workpiece is photographed by an imaging unit as it is moved from the box to the predetermined position by a move-out unit, and the state of the workpiece is corrected by a correction unit in a manner consistent with the reference image; and a holding step, in which the corrected workpiece is conveyed by a conveying unit and held on the chuck table. Thus, even if the shape of the workpiece is quadrilateral, circular, or other shapes, it is easy to set up the conveying mechanism, eliminating the cumbersome problem. Attached Figure Description

[0013] Figure 1 This is an overall perspective view of a grinding apparatus having the conveying mechanism of the present invention.

[0014] Figure 2 Is with Figure 1 The grinding apparatus shown is a perspective view of the transport mechanism corresponding to the quadrilateral wafer, the circular wafer, and the chuck table.

[0015] Figure 3 This is a perspective view illustrating an embodiment of the reverse conveying process.

[0016] Figure 4 This is a perspective view illustrating an implementation of the reference image storage process.

[0017] Figure 5 This is a perspective view showing how a wafer is removed from a cassette during a correction process.

[0018] Figure 6 This is a perspective view showing an embodiment of the correction process.

[0019] Figure 7 This is a perspective view illustrating other embodiments of the transfer unit.

[0020] Figure 8 It shows through Figure 7 A perspective view of an implementation method for the correction process performed by the shown transfer unit.

[0021] Label Explanation

[0022] 1: Grinding device; 2: Conveying mechanism; 3: Holding unit; 32: Chuck table; 34a: First area; 34b: Second area; 4: Grinding unit; 42: Grinding wheel; 43: Grinding tool; 5: Box; 51: Box table; 6: Transfer unit; 60: Arm base; 61: Arm mechanism; 62: Robotic arm; 63: Suction hole; 6': Transfer unit; 60: Arm base; 61: Arm mechanism; 64: Robotic arm; 65: Robotic arm cover; 6 6: Rotating plate; 67: Suction hole; 7: Temporary worktable; 71: Adsorption chuck; 72: Base; 73: Moving unit; 8: Conveying unit; 81: Arm; 82: Holding part; 83: Base end; 9: Imaging unit; 10A: Wafer (quadrilateral); 10B: Wafer (circular); 11: Grinding feed unit; 12: Display unit; 20: Device housing; 21: Main body; 22: Vertical wall; 100: Control unit; 120, 130: Image information. Detailed Implementation

[0023] Hereinafter, embodiments of the conveying mechanism and the method for setting the conveying mechanism based on the present invention will be described in detail with reference to the accompanying drawings.

[0024] Figure 1 A perspective view of a grinding apparatus 1 equipped with the conveying mechanism 2 of this embodiment is shown. The grinding apparatus 1 includes: a holding unit 3 having a chuck table 32 for attracting and holding plate-shaped workpieces; a grinding unit 4 for grinding the workpieces attracted and held by the chuck table 32; a box 5 placed on a box table 51 for storing multiple workpieces; a transfer unit 6 for supporting and transferring workpieces from the box 5; a temporary placement table 7 for temporarily placing workpieces transferred out by the transfer unit 6; a conveying unit 8 for transferring workpieces from the temporary placement table 7 to the chuck table 32 and placing them at a desired position on the chuck table 32; a photographing unit 9 for photographing and storing the state of the workpieces transferred to the temporary placement table 7; a display unit 12; and a control unit 100 connected to the display unit 12 and controlling each operating unit. Furthermore, the workpiece in this embodiment is... Figure 2 The chuck stage 32 corresponds to any one of the four wafers shown, either the quadrilateral wafer 10A or the circular wafer 10B.

[0025] Figure 1The grinding apparatus 1 shown has an apparatus housing 20. The apparatus housing 20 has: a main body 21 in a generally rectangular parallelepiped shape; and an upright wall 22 disposed at the rear end of the main body 21, erected vertically. A retaining unit 3 is disposed on the main body 21, and corrugated portions are provided on both sides of the retaining unit 3 in the Y-axis direction indicated by arrow Y. Inside the main body 21 are housed a rotary drive unit for rotating the chuck table 32 of the retaining unit 3 and a moving unit for moving the chuck table 32 along the Y-axis direction (both omitted from the diagram). By actuating the moving unit, the corrugated portions extend and retract, thereby enabling… Figure 1 The chuck table 32 moves between the forward-facing loading / unloading area (where the unprocessed workpiece is placed) and the inner machining area (where the workpiece is machined directly below the grinding unit 4). Additionally, in Figure 1 For ease of explanation, the control unit 100 is shown outside the grinding device 1, but in reality, the control unit 100 is housed inside the device housing 20.

[0026] The transfer unit 6 is disposed between the box 5 and the temporary worktable 7. The transfer unit 6 has a cylindrical arm base 60, an arm mechanism 61 with multiple arms, and a robotic arm 62 formed at the front end of the arm mechanism 61. An electric motor and cylinder (not shown) are disposed inside the arm base 60, enabling the arm mechanism 61 to rotate and move up and down. An electric motor is also disposed at the connection point of the multiple arms constituting the arm mechanism 61, enabling the arm mechanism 61 to fold or unfold. In this embodiment, the robotic arm 62 is formed in a generally U-shape, with multiple suction holes 63 on its front side. These suction holes 63 are connected to a suction unit (not shown), enabling the suction of plate-shaped workpieces. The robotic arm 62 can be flipped so that the surface with the suction holes 63 faces upwards or downwards, allowing the robotic arm 62 of the transfer unit 6 to be inserted into the box 5, suction and remove the stored workpiece, transport it to the temporary worktable 7, flip it over, and place it from above.

[0027] The temporary worktable 7 has an adsorption chuck 71 and a base 72 supporting the adsorption chuck 71. An adsorption unit (not shown) that generates a negative pressure is connected to the adsorption chuck 71. Additionally, the base 72 has a moving unit 73 that functions as a correction unit to adjust the state of the workpiece held by the adsorption chuck 71. This moving unit 73 can rotate the adsorption chuck 71 by a desired angle and move it a desired distance in the X-axis and Y-axis directions (as shown by arrows in the figure). For example, the moving unit 73 can move the adsorption chuck 71 approximately 10 mm in the X-axis and Y-axis directions. When the temporary worktable 7 is not holding a workpiece, its center is positioned at the center of the area that allows movement in the X-axis and Y-axis directions. Hereinafter, the position where the temporary worktable 7 is positioned in this way will be referred to as the "origin position".

[0028] The conveying unit 8 has: an arm 81; a holding part 82 disposed at the front end of the arm 81; and a base end 83, which causes the arm 81 to rotate and extend and retract in the vertical direction. By rotating the arm 81 around the base end 83, the workpiece attracted by the suction chuck 71 of the temporary worktable 7 can be conveyed to the chuck worktable 32.

[0029] As shown in the figure, the imaging unit 9 is positioned directly above the center of the suction chuck 71 when the temporary worktable 7 is positioned at its origin, and takes a picture from below. The imaging unit 9 is fixed to any position on the device housing 20 by means of a fixing component (not shown). The imaging unit 9 has a memory (not shown) for storing the captured images; in this embodiment, this memory is provided in the control unit 100. The images captured by the imaging unit 9 can be stored in this memory and can be displayed on the display unit 12.

[0030] Figure 1The grinding apparatus 1 shown includes a grinding feed unit 11 that moves the grinding unit 4 vertically along the pair of guide rails 221, 221. The grinding unit 4 includes a grinding wheel 42 driven by an electric motor or the like and supported for rotation; and a plurality of grinding tools 43 arranged in a ring on the lower surface of the grinding wheel 42. The grinding feed unit 11 has an external threaded rod 11a, which is disposed on the front surface side of the vertical wall 22 and extends vertically. The upper and lower ends of the external threaded rod 11a are supported by the vertical wall 22 for free rotation. A pulse motor 11b, serving as a drive source for rotating the external threaded rod 11a, is disposed at the upper end of the external threaded rod 11a, and the output shaft of the pulse motor 11b is connected to the external threaded rod 11a. A threaded connection portion (not shown) is formed on the rear surface of the movable base 41. An internally threaded hole extending in the vertical direction is formed in this connection portion, and the aforementioned externally threaded rod 11a is screwed into the internally threaded hole. Such a grinding feed unit 11 can cause the pulse motor 11b to rotate forward, thereby causing the grinding unit 4 and the movable base 41 to descend together, and cause the pulse motor 11b to rotate in reverse, thereby causing the grinding unit 4 and the movable base 41 to rise together.

[0031] In addition, the conveying mechanism 2 of this embodiment includes the above-mentioned conveying unit 6, conveying unit 8, shooting unit 9, and moving unit 73 of temporary worktable 7 which functions as a correction unit. The state of the workpiece photographed by the shooting unit 9 is corrected by the moving unit 73. The corrected workpiece is conveyed to the chuck worktable 32 by the conveying unit 8 and accurately placed at the required position on the chuck worktable 32.

[0032] In addition to the aforementioned shooting unit 9, the holding unit 3, grinding unit 4, moving unit 6, temporary worktable 7, and conveying unit 8 are all connected to the control unit 100 and are appropriately controlled according to the instruction signals from the control unit 100.

[0033] The grinding apparatus 1 of this embodiment generally has the structure described above. Hereinafter, the function and role of the conveying mechanism 2 provided in the grinding apparatus 1 and the setting method of the conveying mechanism 2 will be explained.

[0034] The workpiece conveyed by the conveying mechanism 2 of this embodiment can be transferred from... Figure 2Choosing between a quadrilateral wafer 10A and a circular wafer 10B, the chuck stage 32 has: a first region 34a, corresponding to the shape of the quadrilateral wafer 10A, for attracting the wafer 10A; and a second region 34b, corresponding to the shape of the wafer 10B, for attracting the circular wafer 10B together with the first region 34a. The first region 34a and the second region 34b are divided by a dividing section 33, which can generate attraction negative pressure in both regions. When attracting and holding the wafer 10A, attraction negative pressure is generated only in the first region 34a; when attracting and holding the circular wafer 10B, attraction negative pressure is generated in both the first region 34a and the second region 34b. In the embodiment described below, the case of transporting the quadrilateral wafer 10A by the transport mechanism 2 will be explained.

[0035] According to Figure 1 The grinding apparatus 1 described herein contains multiple wafers 10A in its housing 5. These wafers are removed by the robotic arm 62 of the removal unit 6 and placed on the suction chuck 71 of the temporary worktable 7. Here, when removing the wafers 10A from the housing 5, if they are supported in the desired position, they can be accurately transferred to the suction chuck 71 of the temporary worktable 7, and then precisely transferred from the suction chuck 71 to the chuck worktable 32 positioned in the removal / input area. However, in reality, while the wafers 10A are stored in the housing 5 with a predetermined gap, their position may not be constant when removed from the housing 5. There are issues with the position of the wafers 10A placed on the suction chuck 71 of the temporary worktable 7, i.e., deviations in rotation direction, X-axis direction, and Y-axis direction. Furthermore, when the wafer 10A is transferred from the temporary stage 7 by the transfer unit 8 under this deviation, the following problems arise: the wafer 10A cannot be accurately positioned at the required position, i.e., the first region 34a, on the chuck stage 32; negative pressure leaks from the gap formed between the wafer 10A and the first region 34a; the wafer 10A cannot be properly held by the chuck stage 32, and obstacles are created during grinding. Additionally, even if the wafer 10A is properly positioned on the temporary stage 7, the transfer unit 8 may still fail to properly transfer the wafer 10A to the chuck stage 32. Therefore, in order to accurately transfer the wafer 10A removed from the cartridge 5 to the first region 34a of the chuck stage 32 and properly hold it, the moving unit 73 of the temporary stage 7, which functions as a correction unit, is activated to perform a correction process to correct the state of the wafer 10A.

[0036] When implementing the above-mentioned corrections, information about the state of the reference used to correct the state of the wafer 10A is required. If the state of this reference can be set efficiently, the cumbersome problem of moving the wafer 10A out of the cartridge 5 for processing can be further eliminated, and the grinding process of the grinding apparatus 1 can be performed efficiently. Hereinafter, the method for setting the conveying mechanism 2 implemented in this embodiment will be described.

[0037] First, when implementing the setting method of the conveying mechanism 2 in this embodiment, the chuck table 32 is pre-positioned in... Figure 1 The chuck table 32 is located in the loading / unloading area. The required position of the chuck table 32 at this time, i.e., the orientation of the first area 34a, is not particularly limited, but for example... Figure 2 The state shown is maintained as the proper state of the chuck stage 32. The following loading process is performed: the operator accurately positions and loads the quadrilateral wafer 10A into the first region 34a of the chuck stage 32, which is positioned in such a proper state.

[0038] Next, as Figure 3 As shown in (a), the reverse transfer process is performed as follows: the wafer 10A, placed on the chuck stage 32, is attracted by the transfer unit 8 and transferred in the reverse direction to a predetermined position. More specifically, as... Figure 3 As shown in (a), the arm 81 of the transfer unit 8 is rotated in the direction indicated by arrow R1, and the holding part 82 attracts the wafer 10A held by the chuck stage 32 positioned in the transfer-out and transfer-in area. Next, as... Figure 3 As shown in (b), the arm 81 of the transfer unit 8 is rotated in the direction indicated by arrow R2 to transfer and place the wafer 10A on the temporary worktable 7, which is positioned at a predetermined location in this embodiment, for attraction and holding. This reverse transfer operation is achieved by reversing the following operation: after the wafer 10A removed from the cassette 5 is attracted and held in the suction chuck 71 of the temporary worktable 7, it is transferred from the suction chuck 71 to the chuck worktable 32 by the transfer unit 8. Through this reverse transfer process, the state of the wafer 10A held by the suction chuck 71 of the temporary worktable 7 becomes the reference state when it is accurately transferred from the suction chuck 71 of the temporary worktable 7 to the desired position, i.e., the first region 34a, of the chuck worktable 32.

[0039] like Figure 4 As shown, the wafer 10A, which is reverse-transferred and placed in a specified position, namely the suction chuck 71 of the temporary worktable 7, is attracted and held by the imaging unit 9. The image showing the state of the wafer 10A is captured and stored as a reference image 110 in the memory of the imaging unit 9 configured in the control unit 100 (reference image storage process).

[0040] As described above, if the reference image 110 stored in the reference image storage process is stored in the memory of the imaging unit 9, the grinding process of the grinding apparatus 1 described below is performed.

[0041] When performing grinding, such as Figure 5 As shown, the transfer unit 6 is activated to suction and support the wafer 10A stored in the cassette 5, remove it, and place it on the suction chuck 71 of the temporary worktable 7 for suction and holding. Next, as... Figure 6 As shown, the imaging unit 9 captures images of the state of the wafer 10A held and attracted by the temporary worktable 7. The captured image information 120 is sent to the control unit 100 and displayed on the display unit 12. However, as described above, the wafer 10A is stored in the cassette 5 with gaps between it, and a predetermined deviation may occur when it is attracted and held by the suction chuck 71 on the temporary worktable 7. As described above, the control unit 100 stores a reference image 110 stored in the reference image storage process in its memory, and the control unit 100 follows the... Figure 6 The display unit 12 compares the image information 120, which shows the actual state of the wafer 10A as it is moved from the cartridge 5 to the temporary worktable 7, with the reference image 110, and detects any shift in state between the two. More specifically, it detects the positional shift X1 in the X-axis direction and Y1 in the Y-axis direction between the center O1 of the reference image 110 and the center O2 of the image information 120 showing the actual state of the wafer 10A, and further detects the angular shift θ1 between a predetermined edge 112 of the reference image 110 and the edge 122 of the image information 120 that is closest to the predetermined edge 112.

[0042] As described above, if an offset X1 in the X-axis direction, an offset Y1 in the Y-axis direction, and an offset θ1 in the rotational direction of the actual wafer 10A relative to the reference image 110 are detected, the moving unit 73, which is configured as a correction unit, is activated to adjust the position of the temporary stage 7 according to X1 in the X-axis direction, Y1 in the Y-axis direction, and θ1 in the rotational direction (correction process) in order to make the state of the wafer 10A held by the suction chuck 71 of the temporary stage 7 consistent with that of the reference image 110.

[0043] If the above-described correction process is performed, the transfer unit 8 is activated to transfer the wafer 10A held by the temporary worktable 7 and place it on the chuck worktable 32 for suction and holding (holding process). According to the above-described method of setting up the transfer mechanism 2, which includes a placement process, a reverse transfer process, a reference image storage process, a correction process, and a holding process, as described above, the wafer 10A placed on the temporary worktable 7 is aligned with the position of the reference image 110. Therefore, the wafer 10A transferred by the transfer unit 8 is accurately positioned in the first region 34a of the chuck worktable 32, thereby preventing poor suction. Furthermore, in this embodiment, by including the above-described reverse transfer process, a state is generated at a predetermined position where the wafer 10A is removed, which is then photographed and stored. Therefore, setting up the transfer mechanism 2 becomes easier, eliminating the cumbersome problem. Furthermore, in this embodiment, after the method of setting up the conveying mechanism 2 is implemented, the chuck table 32 is moved to the processing area directly below the grinding unit 4, and grinding is performed by the grinding unit 4 to achieve the desired thickness. In the above embodiment, the workpiece conveyed by the conveying mechanism 2 is described as a quadrilateral wafer 10A, but the present invention is not limited to this; it can also be applied to the case of using a circular wafer 10B, or wafers of shapes other than quadrilateral or circular.

[0044] The conveying mechanism 2 of this embodiment has the structure described above, so that even if the shape of the workpiece is a quadrilateral, a circle or other shape as described above, it is easy to set up the conveying mechanism and eliminate the troublesome problem.

[0045] The conveying mechanism of the present invention is not limited to the conveying mechanism 2 of the above embodiment. For example, the correction unit is not limited to the moving unit 73 of the temporary workbench 7 provided as the correction unit in the above embodiment, and various modifications can be adopted. For example, it can replace Figure 1 The transfer unit 6 shown is configured in the grinding apparatus 1 and employs... Figure 7 The transfer unit 6' shown is used to perform the correction process performed by the moving unit 73. Furthermore, in this embodiment, the temporary stage 7 is not used; the transfer unit 8 attracts the wafer 10A supported by the transfer unit 6' and transfers it to the chuck stage 32. Additionally, regarding... Figure 7 The shown moving unit 6' is for use with Figure 1 The same structure as the transport unit 6 shown is labeled with the same reference numerals, and its detailed description is appropriately omitted.

[0046] Figure 7The shown transfer unit 6' has an arm base 60 and an arm mechanism 61, with a robotic arm 64 at the front end of the arm mechanism 61. The robotic arm 64 has a generally annular robotic arm cover 65 and a rotating plate 66 supported by the robotic arm cover 65. The rotating plate 66 can rotate in the direction indicated by arrow R4 to a desired position. A plurality of suction holes 67 as shown in the figure are provided on the front side of the rotating plate 66, and the robotic arm 64 is connected to a suction unit (not shown) that can generate a suction negative pressure in the suction holes 67.

[0047] The aforementioned removal unit 6' is similar to the removal unit 6 described in the previous embodiment, using the negative pressure generated in the suction hole 67 to attract and support the wafer 10A housed in the cartridge 5, as... Figure 8 As shown, it is moved to the designated position where the shooting unit 9 is provided (in the above embodiment, the position where the temporary worktable 7 is provided).

[0048] Here, while the robotic arm 64 attracts and holds the wafer 10A, which has been moved to the designated position, the imaging unit 9 captures an image of the wafer 10A, obtaining image information 130, which is then sent to the control unit 100. The image information 130 sent to the control unit 100 is compared with the pre-stored reference image 110, and the state offset between the two is detected in the same manner as in the above embodiment. More specifically, the position offset X2 in the X-axis direction and Y-axis direction between the center O1 of the reference image 110 and the center O3 of the captured image information 130 showing the actual state of the wafer 10A are detected, and then the angle offset θ2 between the designated edge 112 of the reference image 110 and the edge 132 of the image information 130 closest to the designated edge 112 is detected. As described above, if an offset X2 in the X-axis direction, an offset Y2 in the Y-axis direction, and an offset θ2 in the rotation direction of the image information 130 showing the actual state of the wafer 10A relative to the reference image 110 are detected, the arm mechanism 61 is activated to adjust the position of the wafer 10A in the X-axis direction by X2 and in the Y-axis direction by Y2, so that the center O1 of the reference image 110 is aligned with the center O3 of the image information 130, in order to make the state of the wafer 10A attracted by the robot arm 64 consistent with the reference image 110. Furthermore, the rotating plate 66 of the robot arm 64 is activated to rotate the wafer 10A by θ2, performing a position correction process to ensure that the position of the wafer 10A held by the robot arm 64 is completely consistent with the position stored in the reference image 110. After performing this correction process, the transfer unit 8 is activated, thereby transferring the wafer 10A from the robot arm 64 and accurately positioning it in the first region 34a (holding process) of the chuck stage 32. By implementing the method of setting up the conveying mechanism 2 in this way, the same effect as the above-described embodiment can be obtained. Next, the chuck table 32 is moved to the processing area directly below the grinding unit 4, and the grinding unit 4 performs grinding processing in a manner that achieves the desired thickness.

[0049] The correction unit of the present invention can be further modified. For example, instead of the mechanism that moves the material from the predetermined position to the chuck table 32 by rotation as described above for the conveying unit 8, a mechanism that moves the material linearly to the chuck table 32 in the Y-axis direction can be used. In this case, the control amount in the Y-axis direction indicated by the control unit 100 is corrected according to the aforementioned offset Y1, thereby enabling correction in the Y-axis direction.

[0050] As understood from the above description, the correction unit in this invention can be any unit capable of performing the following steps: determining any position during the period from when the wafer 10A is transferred from the cassette 5 to the chuck stage 32 as a predetermined position; setting a reference state at the predetermined position where the wafer 10A is accurately transferred to the first region 34a of the chuck stage 32; comparing the state of the actually transferred wafer 10A with the reference state; and correcting the offset in the X-axis direction, the offset in the Y-axis direction, and the offset in the rotation direction by using the transfer unit, the transfer unit, the rotation drive unit of the chuck stage, or a combination thereof, in a manner that makes the state of the wafer 10A consistent with the reference state.

Claims

1. A method for setting up a conveying mechanism, the conveying mechanism corresponding to the shapes of circular and quadrilateral workpieces. The conveying mechanism comprises: The transfer unit removes the box-supported workpiece from the box worktable; The imaging unit captures and stores images of the workpiece being moved to a designated position by the transfer unit. The correction unit corrects the state of the workpiece captured by the imaging unit. as well as The transfer unit transports the corrected workpiece to the chuck table and places it at the desired position on the chuck table. in, The method for setting up this conveying mechanism involves the following steps: The loading process involves placing the workpiece at the desired position on the chuck table. The reverse conveying process involves using the conveying unit to reverse-transfer the workpiece placed on the chuck table to the designated position; and The reference image storage process involves using the imaging unit to capture images of the workpiece being transported in reverse to the designated position, and storing these images as reference images. The method for setting up this conveying mechanism comprises the following steps: In the correction process, the imaging unit captures an image of the workpiece being moved from the box to the designated position by the transfer unit, and the correction unit corrects the workpiece's state in a manner consistent with the reference image; and The process involves using the conveying unit to move the corrected workpiece and hold it on the chuck table.

Images