Processing apparatus and method for processing workpieces

Abstract

In a machining apparatus, the machining depth of the workpiece held on the chuck table is kept constant. [Solution] The processing apparatus (10) includes a chuck table (20) for holding a workpiece (W), a processing unit (11) for processing the workpiece held on the chuck table to a predetermined depth from the top surface, a processing feed unit (25) for relative processing feed between the chuck table and the processing unit, a fluid supply unit (50) for supplying fluid to the chuck table, and a control unit (15) for controlling the processing unit and the processing feed unit so that fluid is supplied to the chuck table at a predetermined flow rate for a predetermined time before processing the workpiece.

Description

[Technical Field]

[0001] The present invention relates to a processing apparatus and a workpiece processing method. [Background Art]

[0002] As disclosed in Patent Documents 1 and 2, a processing apparatus that processes a workpiece performs idling while supplying processing water before processing the workpiece, so that the temperature of each part is the same as that during processing, thereby preventing processing defects caused by shape changes of each part. [Prior Art Literature] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2010-158760 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2017-019067 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] However, during the period from after idling until the workpiece is conveyed from the cassette to the chuck table, and the period from after measuring the top surface height of the workpiece conveyed to the chuck table until starting processing, the chuck table undergoes a shape change (thermal deformation) due to the influence of temperature change caused by no processing water being supplied. Further, since the length of these periods varies, the amount of shape change of the chuck table also varies. If the workpiece is processed in a state where the amount of shape change of the chuck table varies, variations occur in processing accuracy (processing depth accuracy). For example, there is a difference between the time taken for the first workpiece conveyed from the cassette to be conveyed to the chuck table and the time taken for the second workpiece to be conveyed. When performing processing in which a cutting blade is cut into the workpiece in the thickness direction, there is a problem that the cutting depth tends to differ between the first workpiece and the second workpiece. In other words, the magnitude of the difference in conveyance time is related to the magnitude of the deformation amount of the chuck table.

[0005] Furthermore, cutting machines are equipped with a kerf check function that checks the kerf when the number or distance of kerfs formed on the workpiece by the cutting blade reaches a predetermined number or distance. When a kerf check is performed, machining is temporarily suspended, and the supply of cutting fluid to the chuck table and workpiece is stopped. Machining then resumes after the kerf check is completed. Because the supply of cutting fluid is stopped when a kerf check is performed, the shape of the chuck table changes, and there is a problem that the kerf immediately after the kerf check has a different depth than the kerf before the kerf check. Examples of temporary suspension of machining in cutting machines other than kerf checks include dressing, which sharpens the cutting blade, and setup, which detects the height position of the tip of the cutting blade. Similarly, after dressing or setup, the kerf depth is likely to differ, and in the case of half-cutting, where the workpiece is not completely cut, if the kerf depth differs, there is a problem that the workpiece cannot be divided in the next dividing process.

[0006] Machining units that process a workpiece to a predetermined depth are known to use cutting blades, as well as tools, grinding wheels, laser irradiation units, etc., and various machining devices that perform machining with these machining units also have the same problems as described above.

[0007] Therefore, the processing equipment faces the challenge of maintaining a constant processing depth. [Means for solving the problem]

[0008] One aspect of the present invention is a machining apparatus comprising: a chuck table for holding a workpiece; a machining unit for machining the workpiece held on the chuck table to a predetermined depth from the top surface; a machining feed unit for relative machining feed of the chuck table and the machining unit; and a fluid supply unit for supplying fluid to the chuck table, wherein the apparatus includes a control unit that controls the machining unit and the machining feed unit so as to supply the fluid to the chuck table at a predetermined flow rate for a predetermined time before machining the workpiece.

[0009] The system comprises a cassette stage on which a cassette containing the workpiece is placed, and a transport mechanism that holds and transports the workpiece with respect to the cassette placed on the cassette stage and the chuck table, wherein the control unit preferably supplies the fluid to the chuck table until just before the workpiece held by the transport mechanism is transported to the chuck table.

[0010] One aspect of the present invention is a method for processing a workpiece using a processing apparatus comprising: a chuck table for holding a workpiece; a processing unit for processing the workpiece held on the chuck table from its top surface to a predetermined depth; a processing feed unit for relative processing feed between the chuck table and the processing unit; and a fluid supply unit for supplying fluid to the chuck table, the method comprising: a fluid supply step of supplying the fluid to the chuck table at a predetermined flow rate for a predetermined time; a holding step of holding the workpiece on the chuck table after the fluid supply step; and a processing step of processing the workpiece.

[0011] One aspect of the present invention is a method for processing a workpiece using a processing apparatus comprising: a chuck table for holding a workpiece; a processing unit for processing the workpiece held on the chuck table from its top surface to a predetermined depth; a processing feed unit for relative processing feed between the chuck table and the processing unit; and a fluid supply unit for supplying fluid to the chuck table, the method comprising: a holding step of holding the workpiece on the chuck table; a fluid supply step of supplying the fluid to the workpiece held on the chuck table at a predetermined flow rate for a predetermined time; and a processing step of processing the workpiece. [Effects of the Invention]

[0012] According to the processing apparatus and processing method described above, it is possible to prevent changes in the processing depth of the workpiece due to thermal deformation of the chuck table, thereby keeping the processing depth constant. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view of the processing equipment. [Figure 2] This is a perspective view showing the internal structure of the processing chamber in a processing machine. [Figure 3] This figure shows a first embodiment of a workpiece machining method. [Figure 4] This figure shows a second embodiment of the workpiece processing method. [Figure 5] This is a time chart showing the sequence of operations in a processing machine. [Modes for carrying out the invention]

[0014] The following describes a processing apparatus and processing method according to an embodiment to which the present invention is applied, with reference to the drawings. The X-axis, Y-axis, and Z-axis directions shown in Figures 1 to 4 are perpendicular to each other. The X-axis and Y-axis directions are horizontal. The Z-axis direction is vertical, with the +Z direction being upward and the -Z direction being downward.

[0015] The processing apparatus 10 shown in Figures 1 and 2 is a device for edge trimming a workpiece W, and uses the processing unit 11 shown in Figure 2 to cut the outer circumference of the workpiece W from the top surface to a predetermined depth. As shown in Figure 1, the processing apparatus 10 comprises a base 12 and a processing chamber 13 placed on the base 12. The processing unit 11 is located inside the processing chamber 13.

[0016] As will be described in detail later, the processing unit 11 is equipped with a cutting blade 14 (Figure 2) as a processing tool, and processes the outer periphery of the workpiece W by cutting with the rotating cutting blade 14 (edge ​​trimming). However, the application of the present invention is not limited to such a processing device 10. For example, the processing unit may be equipped with a cutting tool other than a cutting blade, such as a cutting tool, a grinding wheel, or a laser irradiation unit. In terms of the processing method, it can be applied to various types of processing that process the workpiece to a predetermined processing depth, such as cutting with a cutting blade or cutting tool, grinding with a grinding wheel, or laser processing with a laser beam. Furthermore, the processing performed by the processing unit on the workpiece may be other than edge trimming, which removes or thins the outer periphery, such as forming a processing groove, thinning the central part of the workpiece, or thinning the entire workpiece.

[0017] As shown in Figures 3 and 4, the workpiece W is a bonded wafer formed by bonding a disc-shaped first wafer Wa and a second wafer Wb together. Both the first wafer Wa and the second wafer Wb have chamfered edges, and the chamfered edges of the first wafer Wa are removed during edge trimming using the processing apparatus 10. The first wafer Wa is, for example, a semiconductor wafer on which multiple semiconductor devices are formed. The configuration and type of workpiece W are not limited to these; it may be a single wafer that is not bonded together, or a rectangular package substrate, etc.

[0018] The processing apparatus 10 is controlled by a control unit 15 (FIG. 1) to fully automatically perform a series of operations including conveyance processing, processing, cleaning processing and the like on a workpiece W. The control unit 15 includes a processor and a memory, the processor performs processing in accordance with a program stored in the memory, and controls each part of the processing apparatus 10. A processing method described later is executed under control by the control unit 15.

[0019] The processing apparatus 10 has a processing chamber 13, which is an area where a processing unit 11 processes the workpiece W, on the -X direction side of a base 12, and conveys and cleans the workpiece W in an area outside the processing chamber located on the +X direction side of the processing chamber 13. The processing chamber 13 is a side wall on the +X direction side, and includes a partition wall 131 that partitions the inside and the outside of the processing chamber 13.

[0020] As shown in FIG. 1, a cassette stage 16 is provided at an end portion on the -Y direction side of the area outside the processing chamber, and a cassette 18 that accommodates the workpiece W is placed on the cassette stage 16. The cassette stage 16 is moved in the Z-axis direction by an elevating mechanism 17 provided inside the base 12. A plurality of workpieces W can be accommodated in the cassette 18 at intervals in the Z-axis direction, and by elevating and lowering the cassette stage 16 by the elevating mechanism 17, the cassette 18 can be positioned at a height position suitable for taking in and out individual workpieces W.

[0021] A chuck table 20 that holds a workpiece W during processing is moved in the X-axis direction by an X-axis moving mechanism 21 shown in FIG. 2. The X-axis moving mechanism 21 includes a pair of guide rails 211 extending in the X-axis direction and a ball screw 212. An X-axis table 213 is supported so as to be movable in the X-axis direction along the guide rails 211, and the ball screw 212 is screwed into a nut portion provided on the X-axis table 213. When the ball screw 212 is rotated by an X-axis motor 214, the X-axis table 213 moves in the X-axis direction, and the chuck table 20 moves together with the X-axis table 213. As shown in FIG. 1, the chuck table 20 is formed on the upper surface of a base 12 and disposed inside a recess 22 extending in the X-axis direction. The recess 22 is covered by a moving plate 23 that moves in the X-axis direction together with the chuck table 20, and expandable and contractible bellows 24 provided on both sides of the moving plate 23. When the chuck table 20 is moved in the X-axis direction along the recess 22 by the X-axis moving mechanism 21, the chuck table 20 passes below a partition wall 131 and is positioned at a carry-in / out position (FIG. 1) in an area outside the processing chamber on the +X direction side and a processing position (FIG. 2) inside the processing chamber 13 on the -X direction side.

[0022] As shown in FIG. 2, the chuck table 20 is supported on the X-axis table 213 via a rotating mechanism 25, and the chuck table 20 can be rotated about an axis in the Z-axis direction by driving a motor included in the rotating mechanism 25. The rotating mechanism 25 constitutes a processing feed unit that relatively processes and feeds the chuck table 20 and a processing unit 11, and advances processing by moving the workpiece W relative to a cutting blade 14 in the processing feed direction (the circumferential direction of the workpiece W in the present embodiment) during processing. Note that the processing feed direction is not limited thereto. For example, when a processing groove extending in the X-axis direction is formed in a workpiece, the X-axis direction is the processing feed direction, and the X-axis moving mechanism 21 can be applied as the processing feed unit.

[0023] The first transport mechanism 26 and the second transport mechanism 31 shown in Figure 1 transport the workpiece W between the cassette 18 placed on the cassette stage 16 and the chuck table 20 positioned at the loading / unloading position. The first transport mechanism 26 includes a robot hand 261 for holding the workpiece W, a support arm 262 to which the robot hand 261 is connected, a guide rail 263 and a ball screw 264 supported by a partition wall 131 and extending in the Y-axis direction, and a Y-axis motor 265 for rotating the ball screw 264. The support arm 262 is supported so as to be movable in the Y-axis direction along the guide rail 263, and the ball screw 264 is screwed into a nut on the support arm 262. When the ball screw 264 is rotated by the Y-axis motor 265, the support arm 262 moves in the Y-axis direction, and the robot hand 261 moves together with the support arm 262. The first transport mechanism 26 supports the outer edge of the workpiece W with the four inclined surfaces 266 of the robot hand 261.

[0024] The second transport mechanism 31 transports the workpiece W by supporting its lower outer edge (the lower outer edge of the second wafer Wb) with the four support claws 317 of the transport pad 311. The transport pad 311 is equipped with a claw movement mechanism 318 that moves each support claw 317 in the radial direction of the workpiece W to open and close it, and can switch between a state in which the support claws 317 support the lower outer edge of the workpiece W and a state in which they release the support.

[0025] The second transport mechanism 31 includes a slider 312 that is movable in the Y-axis direction, a lifting mechanism 313 that moves the transport pad 311 in the Z-axis direction relative to the slider 312, a guide rail 314 and a ball screw 315 that are supported by the partition wall 131 and extend in the Y-axis direction, and a Y-axis motor 316 that rotates the ball screw 315. The guide rail 314 and ball screw 315 of the second transport mechanism 31 are located above the guide rail 263 and ball screw 264 of the first transport mechanism 26. The slider 312 is supported so as to be movable in the Y-axis direction along the guide rail 314, and the ball screw 315 is screwed into the nut portion of the slider 312. When the ball screw 315 is rotated by the Y-axis motor 316, the slider 312 moves in the Y-axis direction, and the transport pad 311 moves together with the slider 312.

[0026] The operation of transporting the workpiece W from the cassette 18 to the chuck table 20 will be described. With the robot hand 261 of the first transport mechanism 26 supporting the workpiece W on the inclined surface 266, the Y-axis motor 265 is driven to move the robot hand 261 in the +Y direction, thereby allowing the workpiece W to be removed from the cassette 18 placed on the cassette stage 16. The robot hand 261 is stopped above the chuck table 20, which is positioned at the loading / unloading position. The lower outer edge of the workpiece W, which is supported by the robot hand 261 of the first transport mechanism 26, is supported by the four support claws 317 of the transport pad 311 of the second transport mechanism 31, and the workpiece W is transferred from the robot hand 261 to the transport pad 311. Since the position of the outer edge of the workpiece W supported by the inclined surface 266 of the robot hand 261 and the position of the outer edge of the workpiece W supported by the support claws 317 of the transport pad 311 are different in the circumferential direction of the workpiece W, the workpiece W can be directly transferred from the robot hand 261 to the transport pad 311. After that, the robot hand 261 is retracted in the Y-axis direction, and then the lifting mechanism 313 is operated to lower the transport pad 311, bringing the workpiece W closer to the chuck table 20.

[0027] As shown in Figures 1 to 4, the chuck table 20 is equipped with a lifting table 37 that moves up and down in the center, and a lifting cylinder 371 that moves the lifting table 37 up and down. By raising the lifting table 37, the support claws 317 of the transport pad 311 can be inserted into and removed from below the workpiece W placed on the lifting table 37. When transporting the workpiece W to the chuck table 20, the workpiece W is placed on the lifting table 37 which is positioned in the raised position, and the support claws 317 are opened using the claw movement mechanism 318 to release the support of the workpiece W by the transport pad 311. In other words, the workpiece W is transferred from the transport pad 311 with the lifting cylinder 371 in the raised position. After that, when the lifting cylinder 371 is operated to lower the lifting table 37, the entire holding surface 32, which is the upper surface of the chuck table 20, becomes flat, and the workpiece W is supported by the holding surface 32. In this way, the first transport mechanism 26 and the second transport mechanism 31 can be used to remove the workpiece W from the cassette 18 and transport it to the chuck table 20.

[0028] As shown in Figure 1, a cleaning unit 27 is provided at a position on the +Y direction side of the loading / unloading position of the chuck table 20. The cleaning unit 27 cleans the workpiece W after it has been processed by the processing unit 11. The cleaning unit 27 includes a spinner table 28 capable of holding the workpiece W by suction, a rotation mechanism 29 that rotates the spinner table 28 about an axis in the Z direction, and a cleaning nozzle 30 that sprays cleaning water or air toward the spinner table 28. The spinner table 28 is equipped with four support claws 281 arranged opposite each other on its outer circumference. Each support claw 281 is opened and closed using an opening / closing mechanism (not shown).

[0029] The second transport mechanism 31 transports the workpiece W between the chuck table 20, positioned at the loading / unloading position, and the washing unit 27. With the workpiece W supported on the holding surface 32 of the chuck table 20, the lifting cylinder 371 is operated to raise the lifting table 37 together with the workpiece W, and the claw movement mechanism 318 is used to close the support claws 317 of the transport pad 311, so that the lower outer edge of the workpiece W is supported by the support claws 317. Then, the lifting mechanism 313 is operated to raise the transport pad 311, separating the workpiece W from the chuck table 20. The Y-axis motor 316 is operated to move the transport pad 311 in the +Y direction and stop it above the spinner table 28, and the lifting mechanism 313 is operated to lower the transport pad 311. When the workpiece W reaches the height of the spinner table 28, the opening / closing mechanism is used to close the support claws 281, so that the outer edge of the workpiece W is supported by the support claws 281. Furthermore, the support claws 317 of the transport pad 311 are opened using the claw movement mechanism 318 to release the support of the workpiece W by the transport pad 311. In this way, the workpiece W can be transported from the chuck table 20 to the washing unit 27 using the second transport mechanism 31.

[0030] The cleaning unit 27 cleans the workpiece W by spraying cleaning water from the cleaning nozzle 30 onto the workpiece W while rotating the spinner table 28, which has its outer edge supported by support claws 281, using a rotation mechanism 29. After cleaning the workpiece W, it is dried by blowing air from the cleaning nozzle 30 onto the workpiece W. Note that the nozzle for spraying cleaning water and the nozzle for spraying air may be provided separately.

[0031] As shown in Figures 3 and 4, the chuck table 20 has a suction recess 33 on the holding surface 32 that holds the workpiece W, and a suction channel 34 is connected to the suction recess 33. The suction channel 34 is connected to a suction source 36 via an on-off valve 35. By opening the on-off valve 35 and operating the suction source 36, air is drawn in from the suction recess 33 through the suction channel 34, creating negative pressure on the holding surface 32 and holding the lower surface of the workpiece W to the holding surface 32 by suction. The suction recess 33 is formed in an annular shape at a position close to the outer circumference of the holding surface 32 (outside the lifting table 37). Note that the suction structure in the chuck table 20 is not limited to that of this embodiment, and the holding surface 32 may be made of a porous material such as porous ceramics, and the air inside the porous material may be drawn in to hold the workpiece W to the holding surface 32 by suction.

[0032] As shown in Figure 2, the machining unit 11 is supported so as to be movable in the Y-axis direction via a Y-axis movement mechanism 38 and so as to be movable in the Z-axis direction via a Z-axis movement mechanism 39, with respect to a column 40 provided in the machining chamber 13. The Y-axis movement mechanism 38 includes a pair of guide rails 381 and a ball screw 382 attached to the column 40 and extending in the Y-axis direction, and the Y-axis table 383 is supported so as to be movable in the Y-axis direction along the guide rails 381, and the ball screw 382 is screwed into a nut portion on the Y-axis table 383. When the ball screw 382 is rotated by the Y-axis motor 384, the Y-axis table 383 moves in the Y-axis direction. The Z-axis movement mechanism 39 includes a pair of guide rails 391 and a ball screw 392 attached to the Y-axis table 383 and extending in the Z-axis direction, and the Z-axis table 393 is supported so as to be movable in the Z-axis direction along the guide rails 391, and the ball screw 392 is screwed into a nut portion on the Z-axis table 393. When the ball screw 392 is rotated by the Z-axis motor 394, the Z-axis table 393 moves in the Z-axis direction.

[0033] The machining unit 11 includes a spindle housing 41 attached to the lower end of the Z-axis table 393, and a spindle 42, which is a rotating shaft extending in the Y-axis direction, is arranged inside the spindle housing 41. The spindle 42 is rotated by a spindle motor (not shown) provided inside the spindle housing 41. An annular cutting blade 14 is attached to the -Y-direction end of the spindle 42, and the cutting blade 14 rotates together with the spindle 42.

[0034] A blade cover 43, which surrounds a portion of the outside of the cutting blade 14, is attached to the spindle housing 41, and cutting fluid nozzles 44 and 45 are supported on the blade cover 43. Cutting fluid (processing fluid) supplied from a cutting fluid supply source 46 is sprayed from the cutting fluid nozzles 44 and 45. Cutting fluid nozzle 44 sprays cutting fluid towards the lower end of the cutting blade 14 (near the processing point when the cutting blade 14 cuts into the workpiece W). Cutting fluid nozzle 45 sprays cutting fluid towards the side of the cutting blade 14.

[0035] A top surface height measuring device 47 is mounted on the spindle housing 41 near the blade cover 43. The top surface height measuring device 47 is a non-contact sensor that receives light or ultrasonic waves emitted toward the object to be measured and measures the distance to the object. It can measure the height position of the holding surface 32 of the chuck table 20 located below the processing unit 11, and the height position of the top surface of the workpiece W held by the holding surface 32 of the chuck table 20.

[0036] The processing apparatus 10 is equipped with a fluid supply unit 50 capable of supplying fluid to the chuck table 20, separate from the cutting water nozzles 44 and 45 in the processing unit 11. As shown in Figures 3 and 4, the fluid supply unit 50 includes a water nozzle 51 connected to a water supply source 52 via an on-off valve 53, and an air nozzle 54 connected to an air supply source 55 via an on-off valve 56. As shown in Figure 1, the water nozzle 51 and the air nozzle 54 are each located near the lower end of the partition wall 131, extending in the Y-axis direction and traversing the recess 22, and are positioned above the chuck table 20 in the Z-axis direction. The positions of the water nozzle 51 and the air nozzle 54 in the X-axis direction are between the loading / unloading position and the processing position of the chuck table 20.

[0037] With the chuck table 20 positioned below the fluid supply unit 50, it is possible to supply water to the chuck table 20 from the water nozzle 51 and air to the chuck table 20 from the air nozzle 54. The lengths of the water nozzle 51 and air nozzle 54 in the Y-axis direction are greater than the diameter of the holding surface 32 of the chuck table 20. Therefore, the fluid supply unit 50 can supply water and air to a wide area of ​​the chuck table 20. Furthermore, by rotating the chuck table 20 with the rotation mechanism 25 or moving the chuck table 20 in the X-axis direction with the X-axis movement mechanism 21 while supplying water from the water nozzle 51 and air from the air nozzle 54, water and air can be supplied to the entire chuck table 20.

[0038] A machining method for machining a workpiece W using a machining apparatus 10 having the above configuration will now be described. The operation of each part of the machining apparatus 10 described below is performed under the control of the control unit 15, and unless the controlling entity is explicitly stated, it is assumed that the control unit 15 is in control. First, with reference to Figure 3, a first embodiment of the machining method of this disclosure will be described.

[0039] [Fluid supply process] As shown in Figure 3(A), before the workpiece W is held in the chuck table 20, a fluid supply process is performed in which fluid is supplied to the chuck table 20 at a predetermined flow rate for a predetermined time. Specifically, the control unit 15 operates the X-axis motor 214 of the X-axis movement mechanism 21 so that the chuck table 20 is positioned below the fluid supply unit 50, and the on / off valve 53 is opened to send water from the water supply source 52 to the water nozzle 51. As a result, water is supplied from the water nozzle 51 to the chuck table 20 below. While the water is being supplied from the water nozzle 51, the control unit 15 operates the rotation mechanism 25 to rotate the chuck table 20. As a result, water is distributed throughout the entire chuck table 20. The water supplied to the chuck table 20 from the water nozzle 51 cleans the holding surface 32 of the chuck table 20.

[0040] After supplying water from the water nozzle 51 at a predetermined flow rate for a predetermined time, the control unit 15 closes the on-off valve 53 to stop the water supply to the chuck table 20. Next, the control unit 15 opens the on-off valve 56 to send air from the air supply source 55 to the air nozzle 54. As a result, air is supplied to the chuck table 20 from the air nozzle 54. While supplying air from the air nozzle 54, the control unit 15 operates the rotation mechanism 25 to rotate the chuck table 20, blowing air over the entire surface of the chuck table 20. By supplying air to the water-soaked chuck table 20, the chuck table 20 is dried. Note that in Figure 3(A), the states of supplying water from the water nozzle 51 and supplying air from the air nozzle 54 are shown together, but in reality, as shown in the time chart in Figure 5 described later, water is supplied from the water nozzle 51 first, followed by the supply of air from the air nozzle 54.

[0041] When supplying water from the water nozzle 51 or air from the air nozzle 54, the X-axis movement mechanism 21 may be operated by the control unit 15 to change the position of the chuck table 20 in the X-axis direction, within a range that does not deviate from below the fluid supply unit 50.

[0042] The fluid supply process cleans and dries the chuck table 20, and also adjusts the temperature of the chuck table 20. The temperature of the chuck table 20 changes according to the temperature of the water supplied from the water nozzle 51 and the heat of vaporization when the water is dried by supplying air from the air nozzle 54. The temperature of the water supplied from the water nozzle 51 is set to be approximately the same as the temperature of the cutting fluid supplied from the cutting fluid nozzles 44 and 45.

[0043] In addition to the water and air supply described above, the fluid supply process may also consist of air supply only or water supply only.

[0044] After the fluid supply process, a holding process is performed in which the workpiece W is held on the chuck table 20. As a preparatory step for the holding process, a workpiece removal process is performed in which the unprocessed workpiece W, which is stored in the cassette 18, is removed from the cassette 18 and transported to the position of the chuck table 20.

[0045] [Workpiece removal process] In the workpiece removal process, with the cassette 18 placed on the cassette stage 16, the control unit 15 controls the lifting mechanism 17 to adjust the height of the cassette stage 16 so that the height of the workpiece W to be held corresponds to the height of the robot hand 261. Then, the Y-axis motor 265 of the first transport mechanism 26 is operated to move the support arm 262 in the -Y direction, allowing the robot hand 261 to enter the cassette 18 and support the workpiece W on the inclined surface 266 of the robot hand 261. In this embodiment, the workpiece W is supported at four points on its outer edge. Once the robot hand 261 supports the workpiece W, the Y-axis motor 265 is operated to move the support arm 262 in the +Y direction, allowing the workpiece W to be removed from the cassette 18 and stopped above the chuck table 20, which stops at the loading / unloading position.

[0046] [Holding process] In the holding process, the control unit 15 operates the X-axis motor 214 of the X-axis movement mechanism 21 to position the chuck table 20 in the loading / unloading position. With the robot hand 261 stopped above the chuck table 20 in the loading / unloading position, the lower outer edge of the workpiece W (the lower outer edge of the second wafer Wb) is supported by the support claws 317 of the transport pad 311 of the second transport mechanism 31. In other words, the workpiece W is transferred from the robot hand 261 to the transport pad 311. Then, the transport pad 311 is lowered by the lifting mechanism 313 and the workpiece W is placed on the raised lifting table 37 of the chuck table 20. Once the workpiece W is placed on the lifting table 37, the support claws 317 of the transport pad 311 are opened using the claw movement mechanism 318, releasing the support of the workpiece W by the transport pad 311. After that, the lifting table 37 is lowered and air is sucked in from the suction recess 33 of the chuck table 20. As a result, as shown in Figure 3(B), the lower surface of the workpiece W (the lower surface of the second wafer Wb) is held in place by suction against the holding surface 32 of the chuck table 20. The suction holding of the workpiece W by the chuck table 20 continues until the processing steps described later are completed and the workpiece W is handed over to the second transport mechanism 31.

[0047] [Top surface height measurement process] Once the holding process is complete, the control unit 15 operates the X-axis motor 214 of the X-axis movement mechanism 21 to move the chuck table 20 from the loading / unloading position to the processing position. Next, as shown in Figure 3(C), the top surface height is measured. In the top surface height measurement process, the control unit 15 controls the top surface height measuring instrument 47 to measure the height position of the top surface of the workpiece W (top surface of the first wafer Wa) held by the chuck table 20. The control unit 15 operates the rotation mechanism 25 to rotate the chuck table 20 and measures the height position at multiple points in the circumferential direction of the outer circumference of the workpiece W (the part that will become the processed surface after edge trimming). The information on the height position of the top surface of the workpiece W obtained by measurement is stored in the memory of the control unit 15.

[0048] [Processing process] Following the top surface height measurement step, a machining step is performed in which the workpiece W is machined using the machining unit 11. In the machining step, the control unit 15 operates the Y-axis motor 384 of the Y-axis movement mechanism 38 to set the position of the machining unit 11 in the Y-axis direction, and positions the cutting blade 14 above the chamfered portion on the outer circumference of the workpiece W. With the spindle 42 rotating by the spindle motor, the control unit 15 operates the Z-axis motor 394 of the Z-axis movement mechanism 39 to lower the machining unit 11. As a result, as shown in Figure 3(D), the cutting blade 14, which rotates coaxially with the spindle 42, cuts into the outer circumference of the first wafer Wa. Based on the information of the top surface height position of the workpiece W obtained in the top surface height measurement step performed earlier, the control unit 15 lowers the machining unit 11 until it reaches the machining depth set as a machining condition. In this embodiment, the machining depth is set to machine the entire thickness of the first wafer Wa without machining the second wafer Wb. In other words, the cutting blade 14 is set to cut into the boundary between the first wafer Wa and the second wafer Wb in the Z-axis direction. Then, the control unit 15 rotates the cutting blade 14 and operates the rotation mechanism 25 to rotate the chuck table 20 (processing feed) to cut the outer circumference of the first wafer Wa in an annular shape. Through these operations, the chamfered portion of the outer circumference of the first wafer Wa is removed.

[0049] Furthermore, the processing (edge ​​trimming) by the processing unit 11 may, as described above, involve processing the entire thickness of the first wafer Wa, cutting the tip of the cutting blade 14 to a depth shallower than the thickness of the first wafer Wa, or cutting the tip of the cutting blade 14 to a predetermined depth in the second wafer Wb.

[0050] While the machining unit 11 is performing the machining, the control unit 15 controls the supply of cutting fluid from the cutting fluid supply source 46 and sprays the cutting fluid from the cutting fluid nozzles 44 and 45. The cutting fluid supplied from the cutting fluid nozzles 44 and 45 washes away machining debris from the machining point where the cutting blade 14 cuts into the workpiece W and from the surrounding area. In addition, the cutting fluid supplied from the cutting fluid nozzles 44 and 45 cools various parts of the machining apparatus 10 by absorbing the heat generated by the friction between the cutting blade 14 and the workpiece W at the machining point, as well as the heat generated in the machining unit 11 as it rotates the spindle 42 at high speed.

[0051] Once machining of the workpiece W is complete, the control unit 15 operates the Z-axis motor 394 of the Z-axis movement mechanism 39 to raise the machining unit 11 and move the cutting blade 14 away from the workpiece W. Subsequently, the X-axis motor 214 of the X-axis movement mechanism 21 is operated to move the chuck table 20 in the +X direction from the machining position toward the loading / unloading position.

[0052] [Workpiece handling process] Following the processing step, a workpiece transfer step is performed to transport the workpiece W from the chuck table 20 positioned at the loading / unloading position to the spinner table 28 of the cleaning unit 27. The workpiece transfer step is performed using the second transfer mechanism 31. The control unit 15 controls the Y-axis motor 316 of the second transfer mechanism 31 to position the transfer pad 311 above the loading / unloading position of the chuck table 20. The on / off valve 35 is closed to release the suction holding of the lower surface of the workpiece W (the lower surface of the second wafer Wb) to the holding surface 32 of the chuck table 20, and the lifting table 37 is raised together with the workpiece W. The lifting mechanism 313 is controlled to lower the transfer pad 311, bringing it closer to the workpiece W. When the transfer pad 311 has descended to the height of the workpiece W, the support claws 317 of the transfer pad 311 are closed using the claw movement mechanism 318, and the support claws 317 support the outer edge of the lower surface of the workpiece W (the outer edge of the lower surface of the second wafer Wb). Once the transport pad 311 supports the workpiece W, the lifting mechanism 313 is controlled to raise the transport pad 311, separating the workpiece W from the chuck table 20. This completes the transfer of the workpiece W from the chuck table 20 to the transport pad 311.

[0053] Next, the Y-axis motor 316 of the second transport mechanism 31 is operated to move the transport pad 311 in the +Y direction. Once the transport pad 311 is positioned above the spinner table 28 of the washing unit 27, the Y-axis motor 316 is stopped, and the lifting mechanism 313 is controlled to lower the transport pad 311. When the transport pad 311 has lowered and the workpiece W has reached a position where it can be supported by the support claws 281 of the spinner table 28, the support claws 317 of the transport pad 311 are opened using the claw movement mechanism 318, releasing the support of the workpiece W by the support claws 317, and the opening and closing mechanism of the spinner table 28 is driven to support the outer edge of the workpiece W with the four support claws 281. This completes the transport of the workpiece W from the chuck table 20 to the spinner table 28 by the second transport mechanism 31.

[0054] [Washing process] In the cleaning unit 27, a cleaning process is performed to clean the workpiece W after processing. During the cleaning process, the control unit 15 controls the spinner table 28 holding the workpiece W to rotate using the rotation mechanism 29, while cleaning water is sprayed from the cleaning nozzle 30 towards the workpiece W. Once cleaning with the cleaning water is complete, air is sprayed from the cleaning nozzle 30 to dry the workpiece W.

[0055] [Work storage process] Once the cleaning of the workpiece W in the cleaning unit 27 is complete, a workpiece storage process is performed in which the workpiece W is transported from the cleaning unit 27 to the cassette 18 and stored in the cassette 18. The workpiece storage process is performed by the control unit 15 controlling the second transport mechanism 31 and the first transport mechanism 26. First, the transport pad 311 of the second transport mechanism 31 is positioned above the spinner table 28, and the lifting mechanism 313 is controlled to lower the transport pad 311, releasing the support of the workpiece W by the support claws 281 of the spinner table 28, while the outer edge of the workpiece W is supported by the support claws 317 of the transport pad 311. As a result, the workpiece W is transferred from the spinner table 28 to the transport pad 311. More specifically, when a sensor (not shown) on the claw movement mechanism 318 detects that the support claws 317 of the transport pad 311 have supported the workpiece W, the opening and closing mechanism of the spinner table 28 is driven to release the support from the support claws 281, thereby transferring the workpiece W to the transport pad 311.

[0056] The transport pad 311 supporting the workpiece W is moved upward by the operation of the lifting mechanism 313, and then the Y-axis motor 316 is operated to move the transport pad 311 in the -Y direction. When the transport pad 311 reaches above the robot hand 261 of the first transport mechanism 26, the Y-axis motor 316 is stopped, and the transport pad 311 is lowered by the lifting mechanism 313, so that the lower surface of the workpiece W (the lower surface of the second wafer Wb) is placed on the inclined surface 266 of the robot hand 261. By opening the support claws 317 using the claw movement mechanism 318, the support of the workpiece W by the transport pad 311 is released, and the workpiece W is supported by the inclined surface 266 of the robot hand 261, thereby transferring the workpiece W from the transport pad 311 to the robot hand 261.

[0057] Once the robot hand 261 supports the workpiece W, the Y-axis motor 265 is activated to move the support arm 262 in the -Y direction. At this stage, the height of the cassette stage 16 is adjusted by the lifting mechanism 17 so that the height of the workpiece W supported by the robot hand 261 corresponds to the storage position of the workpiece W in the cassette 18. The robot hand 261 then moves into the cassette 18, and the workpiece W is stored in the cassette 18.

[0058] As described above, the processing apparatus 10 performs a series of processes in which the workpiece W removed from the cassette 18 is processed (edge ​​trimmed) by the processing unit 11, the processed workpiece W is washed by the washing unit 27 and stored in the cassette 18. Prior to the processing process, a fluid supply process is performed in which fluid (water from the water nozzle 51 and air from the air nozzle 54) is supplied to the chuck table 20 at a predetermined flow rate for a predetermined time, thereby adjusting the temperature of the chuck table 20. By setting the chuck table 20 to the same temperature conditions as when processing the workpiece W with cutting fluid before proceeding to the processing process, processing defects due to changes in the shape of the chuck table 20 can be prevented.

[0059] Furthermore, when processing multiple workpieces W consecutively, even if the transport time for each workpiece W to the chuck table 20 differs, variations in the amount of deformation of the chuck table 20 (magnitude of thermal deformation) due to differences in transport time can be prevented by standardizing the fluid supply conditions in the fluid supply process (fluid supply time, fluid flow rate) and the length of time from the fluid supply process to the processing process. If there are differences in the amount of deformation of the chuck table 20, the processing depth (cutting depth of the cutting blade 14) when processing multiple workpieces W will differ, which may deviate from the processing setting of processing the entire thickness of the first wafer Wa (see (D) in Figure 3), potentially resulting in processing defects such as processing beyond the first wafer Wa to the second wafer Wb, or processing only up to a certain point in the thickness of the first wafer Wa. By applying the processing method of this disclosure, when processing multiple workpieces W, even if there is a difference in the transport time for each workpiece W to be transported to the chuck table 20, it is possible to prevent differences in the amount of deformation of the chuck table 20 and always maintain a constant processing depth.

[0060] Next, with reference to Figure 4, a second embodiment of the processing method of this disclosure will be described. This second embodiment of the processing method differs from the first embodiment of the processing method in that the holding step shown in Figure 4(A) is performed first, followed by the fluid supply step shown in Figure 4(B). The top surface height measurement step shown in Figure 4(C), the processing step shown in Figure 4(D), and each step after the processing step (workpiece transport step of transporting the workpiece W from the chuck table 20 to the washing unit 27, the washing step in the washing unit 27, and the workpiece storage step of transporting the workpiece W from the washing unit 27 to the cassette 18 for storage) are common to the first embodiment of the processing method described above, so their explanation will be omitted.

[0061] In addition to water supply and air supply, the fluid supply process in this embodiment may also involve air supply only or water supply only.

[0062] [Workpiece removal process and holding process] The control unit 15 controls the first transport mechanism 26, the lifting mechanism 17, the X-axis movement mechanism 21, the second transport mechanism 31, etc., to perform a workpiece removal process in which the workpiece W before processing is removed from the cassette 18, and a holding process in which the workpiece W removed from the cassette 18 is held on the chuck table 20. The details of the workpiece removal process and the holding process are the same as in the first embodiment of the processing method described above, and will not be explained. By performing the holding process, as shown in Figure 4(A), the lower surface of the workpiece W (the lower surface of the second wafer Wb) is held by suction on the holding surface 32 of the chuck table 20.

[0063] [Fluid supply process] Next, as shown in Figure 4(B), a fluid supply process is performed in which fluid is supplied to the chuck table 20, which is holding the workpiece W, at a predetermined flow rate for a predetermined time. Similar to the first embodiment of the processing method described above, the chuck table 20 is positioned below the fluid supply unit 50, and the on / off valve 53 is opened to send water from the water supply source 52 to the water nozzle 51. As a result, water is supplied from the water nozzle 51 to the workpiece W on the chuck table 20. In other words, water is supplied to the chuck table 20 via the workpiece W. The control unit 15 operates the rotation mechanism 25 to rotate the chuck table 20 while supplying water from the water nozzle 51, so that water is distributed throughout the entire chuck table 20. As water is supplied to the chuck table 20 from the water nozzle 51, the workpiece W and the chuck table 20 are cleaned.

[0064] After supplying water from the water nozzle 51 at a predetermined flow rate for a predetermined time, the control unit 15 closes the on-off valve 53 to stop the water supply to the chuck table 20, opens the on-off valve 56 to send air from the air supply source 55 to the air nozzle 54, and supplies air to the chuck table 20 from the air nozzle 54. While supplying air from the air nozzle 54, the rotation mechanism 25 is operated to rotate the chuck table 20, and the chuck table 20 is dried by blowing air onto it. Note that in Figure 4(B), the state of supplying water from the water nozzle 51 and the state of supplying air from the air nozzle 54 are shown together, but in reality, water is supplied from the water nozzle 51 first, and then air is supplied from the air nozzle 54.

[0065] When supplying water from the water nozzle 51 or air from the air nozzle 54, the X-axis movement mechanism 21 may be operated by the control unit 15 to change the position of the chuck table 20 in the X-axis direction, within a range that does not deviate from below the fluid supply unit 50.

[0066] The chuck table 20 is cleaned and dried by the fluid supply process. The temperature of the chuck table 20 is adjusted by the temperature of the water supplied from the water nozzle 51 and the heat of vaporization when air is supplied from the air nozzle 54 to dry the water. After the fluid supply process, the X-axis movement mechanism 21 is operated to move the chuck table 20 to the machining position, and the top surface height measurement process shown in Figure 4(C) and the machining process shown in Figure 4(D) are performed in sequence. Once the machining process is complete, the workpiece transport process is performed to transport the workpiece W from the chuck table 20 to the washing unit 27, the washing process is performed to wash the workpiece W in the washing unit 27, and the workpiece storage process is performed to transport the washed workpiece W from the washing unit 27 to the cassette 18 and store it in the cassette 18 in sequence.

[0067] According to each of the above processing methods, a fluid supply process is performed prior to the processing step in which fluid (water from the water nozzle 51, air from the air nozzle 54) is supplied to the chuck table 20 at a predetermined flow rate for a predetermined time. By setting the chuck table 20 to the same temperature conditions as when processing the workpiece W with cutting fluid before proceeding to the processing step, processing defects due to changes in the shape of the chuck table 20 can be prevented.

[0068] Furthermore, when processing multiple workpieces W consecutively, even if there are differences in the transport time of each workpiece W to the chuck table 20, performing the fluid supply process at a timing close to the processing process prevents differences in the deformation amount of the chuck table 20 during processing, thereby ensuring a constant processing depth. For example, in a processing setting where the entire thickness of the first wafer Wa is processed (see Figure 3(D) and Figure 4(D)), it is possible to prevent processing defects such as processing beyond the first wafer Wa to the second wafer Wb, or processing only up to a certain point in the thickness of the first wafer Wa.

[0069] In the first embodiment of the processing method shown in Figure 3, fluid is supplied from the fluid supply unit 50 to the chuck table 20 (Figure 3(A)) until just before the workpiece W held by the robot hand 261 of the first transport mechanism 26 is transported to the chuck table 20 via the transport pad 311 of the second transport mechanism 31. This effectively suppresses differences in the amount of deformation of the chuck table 20 during processing. In the second embodiment of the processing method shown in Figure 4, the holding process is performed first, and the fluid supply process is performed while each workpiece W is held on the chuck table 20. This allows the temperature adjustment of the chuck table 20 by the fluid supply process to be performed at a timing closer to the processing process, improving the effect of preventing differences in the amount of deformation of the chuck table 20 during processing.

[0070] Next, with reference to the time chart in Figure 5, an example of a suitable operation sequence when processing multiple workpieces W consecutively will be explained. Figure 5 shows the case where each of the workpieces W, from the first to the third to be processed, is processed consecutively from among the multiple workpieces W housed in the cassette 18, with the horizontal axis representing the progression of time. The example in Figure 5 corresponds to a processing method in which the fluid supply process is performed first, followed by the holding process (the first embodiment shown in Figure 3).

[0071] In step 100, the first workpiece removal process is performed using the first transport mechanism 26 to remove the first workpiece W from the cassette 18. While step 100 is in progress, steps 101 and 102, which are fluid supply processes, are performed. In step 101, water is supplied to the chuck table 20 from the water nozzle 51, and in step 102, which follows step 101, air is supplied to the chuck table 20 from the air nozzle 54. Steps 101 and 102 perform cleaning, drying, and temperature adjustment of the chuck table 20. While step 100 is in progress, the chuck table 20 is idle, so steps 101 and 102 can be performed in parallel with step 100, and this parallel processing eliminates waiting time and improves work efficiency. In Figure 5, step 102 is completed before step 100, but the timing of the completion of step 100 and the timing of the completion of step 102 may be synchronized.

[0072] In steps 101 and 102, the chuck table 20 is positioned below the fluid supply unit 50. After step 102, the chuck table 20 is moved in the +X direction by the operation of the X-axis movement mechanism 21 to the loading / unloading position.

[0073] In step 103, a holding process is performed to hold the first workpiece W on the chuck table 20. In the holding process of step 103, the first workpiece W, which is supported by the robot hand 261 of the first transport mechanism 26, is transferred from the robot hand 261 to the transport pad 311 of the second transport mechanism 31, and the transport pad 311 is lowered, and the first workpiece W is transferred to the chuck table 20 at the loading / unloading position. The chuck table 20, which is holding the first workpiece W, is moved from the loading / unloading position to the processing position by the operation of the X-axis moving mechanism 21.

[0074] In step 104, a machining process is performed to machine the first workpiece W using the machining unit 11. Although omitted in Figure 5, a top surface height measurement process may be performed prior to the machining process in step 104, in which the top surface height of the workpiece W is measured using the top surface height measuring instrument 47 (in other words, the machining process may include a top surface height measurement process). During the machining process, cutting fluid is supplied from the cutting fluid nozzles 44 and 45, and the cutting blade 14 of the machining unit 11 is driven into the workpiece W to a predetermined machining depth. Once the machining of the first workpiece W is complete, the chuck table 20 is moved from the machining position to the loading / unloading position by the operation of the X-axis moving mechanism 21.

[0075] In step 105, a workpiece transport process is performed for the first workpiece W after processing, and the first workpiece W is transported from the chuck table 20 to the spinner table 28 of the washing unit 27 using the second transport mechanism 31. In the following step 106, a washing process is performed for the first workpiece W after processing, and the first workpiece W is washed using the washing unit 27.

[0076] In step 107, a workpiece storage process is performed for the first workpiece W after processing. The second transport mechanism 31 and the first transport mechanism 26 are used to transport the first workpiece W from the spinner table 28 of the washing unit 27 to the cassette 18 and store it in the cassette 18. By performing steps 100 to 107, the series of processes for the first workpiece W is completed.

[0077] While processing is underway for the first workpiece W, processing for the second workpiece W is started. Specifically, at the same time as the start of step 104, which processes the first workpiece W, step 108, which is the workpiece removal process for removing the second workpiece W from the cassette 18, is started. While the first workpiece W is being processed, the chuck table 20 is being used by that workpiece W, while the robot hand 261 of the first transport mechanism 26 is free. Therefore, the first transport mechanism 26 can be used to remove the second workpiece W from the cassette 18.

[0078] In step 108, the workpiece removal process, the robot hand 261 of the first transport mechanism 26 supports the second workpiece W on the inclined surface 266 and removes it from the cassette 18, then moves the robot hand 261 upwards in the +Y direction towards the washing unit 27.

[0079] In step 109, the movement of the robot hand 261 in the +Y direction is stopped, and the robot hand 261 is left supporting the second workpiece W, while it waits above the cleaning unit 27.

[0080] While the second workpiece W is waiting in step 109, step 105 is performed in which the first workpiece W, which has been processed in step 104, is supported by the support claws 317 of the transport pad 311 of the second transport mechanism 31 and transported from the chuck table 20 to the washing unit 27, leaving the chuck table 20 free.

[0081] In step 105, as the transport pad 311 of the second transport mechanism 31 moves in the +Y direction toward the washing unit 27, the robot hand 261 of the first transport mechanism 26 is moved in the -Y direction, and the second workpiece W supported by the robot hand 261 is placed above the chuck table 20.

[0082] Following step 105, steps 110 and 111 are performed, which are fluid supply steps to supply fluid to the vacant chuck table 20.

[0083] In step 110, water is supplied from the water nozzle 51 to the chuck table 20 to remove processing debris adhering to the holding surface 32 of the chuck table 20. In addition to supplying water, step 110 may also involve using a cleaning tool such as a brush to clean the holding surface 32 of the chuck table 20.

[0084] In step 111, following step 110, air is supplied from the air nozzle 54 to the holding surface 32 of the chuck table 20 to remove water from the holding surface 32. The chuck table 20 may be rotated when supplying this air. Alternatively, the holding surface 32 of the chuck table 20 may be connected to the suction source 36.

[0085] Steps 110 and 111 clean and dry the chuck table 20 and adjust its temperature. The standby state in step 109 continues until the fluid supply process in steps 110 and 111 is completed.

[0086] In steps 110 and 111, the chuck table 20 is positioned below the fluid supply unit 50. After step 111, the chuck table 20 moves in the +X direction by the operation of the X-axis movement mechanism 21 and is positioned in the loading / unloading position. The fluid supply unit 50 may be configured to enable steps 110 and 111 to be performed when the chuck table 20 is in the loading / unloading position.

[0087] In step 112, a holding process is performed to hold the second workpiece W on the chuck table 20. In the holding process of step 112, the second workpiece W, which was supported by the robot hand 261 of the first transfer mechanism 26 that was waiting in step 109, is transferred from the robot hand 261 to the transfer pad 311 of the second transfer mechanism, and the transfer pad 311 is lowered, and the second workpiece W is transferred to the chuck table 20. The chuck table 20, which is holding the second workpiece W, is moved from the loading / unloading position to the processing position by the operation of the X-axis moving mechanism 21.

[0088] When step 112 is performed, the robot hand 261 of the first transport mechanism 26 becomes available. Step 107, which transports the first workpiece W from the washing unit 27 to the cassette 18 for storage, uses the transport pad 311 of the second transport mechanism 31 for transport in the first half and the robot hand 261 of the first transport mechanism 26 for transport in the second half. By performing step 112 at some point during step 107, the robot hand 261 can be made to transfer the second workpiece W to the transport pad 311 (step 112) and then transport the first workpiece W to the cassette 18 without delay (second half of step 107), thereby enabling efficient operation of the first transport mechanism 26.

[0089] In step 113, a machining process is performed to machine the second workpiece W using the machining unit 11. Although omitted in Figure 5, a top surface height measurement process may be performed prior to the machining process in step 113 using the top surface height measuring instrument 47. Alternatively, the outer circumference of the workpiece W may be imaged with a camera, or the outer circumference may be detected with a sensor to detect the coordinates of three points on the outer circumference of the workpiece W, the coordinates of the center of the workpiece W may be detected, and the amount of deviation between the center of the workpiece W and the rotation center of the chuck table 20 may be calculated. Once the machining of the second workpiece W is complete, the chuck table 20 is moved from the machining position to the loading / unloading position by the operation of the X-axis moving mechanism 21.

[0090] In step 114, a workpiece transport process is performed for the second workpiece W after processing, and the second workpiece W is transported from the chuck table 20 to the spinner table 28 of the washing unit 27 using the second transport mechanism 31. In the following step 115, a washing process is performed for the second workpiece W after processing, and the second workpiece W is washed using the washing unit 27.

[0091] In step 116, a workpiece storage process is performed for the second workpiece W after processing. The second transport mechanism 31 and the first transport mechanism 26 are used to transport the second workpiece W from the spinner table 28 of the washing unit 27 to the cassette 18 and store it in the cassette 18. By performing steps 108 to 116, the series of processes for the second workpiece W is completed.

[0092] While processing is underway for the second workpiece W, processing for the third workpiece W begins. Specifically, at the same time as the start of step 113, which processes the second workpiece W, step 117, which is the workpiece removal process for removing the third workpiece W from the cassette 18, begins. While the second workpiece W is being processed, the chuck table 20 is being used by that workpiece W, while the robot hand 261 of the first transfer mechanism 26 is free. Also, at the final stage of step 107, the robot hand 261 is inserted into the cassette 18 to store the first workpiece W, and at the first stage of step 117, the robot hand 261 can transition to supporting the third workpiece W within the cassette 18, inheriting the operation status of the robot hand 261 at the final stage of step 107. In other words, at the start of step 107, there are no workpieces W in the first and second stages of the cassette 18. In step 107, the workpiece W is placed in the first stage of the cassette 18, the robot hand 261 is moved in the +Y direction from the cassette 18 to remove it, and is raised to a height that can hold the workpiece W stored in the third stage of the cassette 18, and the robot hand 261 is moved in the -Y direction to enter the cassette 18. Therefore, at the timing of step 117 shown in Figure 5, the robot hand 261 of the first transport mechanism 26 can be used to remove the third workpiece W from the cassette 18.

[0093] In step 117, during the workpiece removal process, the robot hand 261 of the first transport mechanism 26 supports the third workpiece W and removes it from the cassette 18, moving the robot hand 261 upwards in the +Y direction towards the washing unit 27.

[0094] In step 118, the movement of the robot hand 261 in the +Y direction is stopped, and the robot hand 261 is left supporting the third workpiece W, while it waits above the cleaning unit 27.

[0095] While the third workpiece W is waiting in step 118, step 114 is performed in which the second workpiece W, which has been processed in step 113, is supported by the support claws 317 of the transport pad 311 of the second transport mechanism 31 and transported from the chuck table 20 to the washing unit 27, leaving the chuck table 20 free.

[0096] Following step 114, steps 119 and 120 are performed, which are fluid supply steps to supply fluid to the vacant chuck table 20.

[0097] In step 119, water is supplied from the water nozzle 51 to the chuck table 20 to remove processing debris adhering to the holding surface 32 of the chuck table 20. In step 110, the procedure is not limited to supplying water; a cleaning tool such as a brush may also be used to clean the holding surface 32 of the chuck table 20 by bringing it into contact with the surface.

[0098] In step 120, following step 119, air is supplied from the air nozzle 54 to the holding surface 32 of the chuck table 20.

[0099] Steps 119 and 120 involve cleaning, drying, and temperature control of the chuck table 20. The standby state in step 118 continues until the fluid supply process in steps 118 and 119 is completed.

[0100] In steps 119 and 120, the chuck table 20 is positioned below the fluid supply unit 50. After step 120, the chuck table 20 moves in the +X direction by the operation of the X-axis movement mechanism 21 to the loading / unloading position.

[0101] In step 121, a holding process is performed to hold the third workpiece W on the chuck table 20. In the holding process of step 121, the third workpiece W, which was supported by the robot hand 261 of the first transfer mechanism 26 that was waiting in step 118, is transferred from the robot hand 261 to the transfer pad 311 of the second transfer mechanism 31, and the transfer pad 311 is lowered, and the third workpiece W is transferred to the chuck table 20. The chuck table 20, which is holding the third workpiece W, is moved from the loading / unloading position to the processing position by the operation of the X-axis moving mechanism 21.

[0102] When step 121 is performed, the robot hand 261 of the first transport mechanism 26 becomes available. Step 116, which transports the second workpiece W from the washing unit 27 to the cassette 18 for storage, uses the transport pad 311 of the second transport mechanism 31 for transport in the first half and the robot hand 261 of the first transport mechanism 26 for transport in the second half. By performing step 121 midway through step 116, the robot hand 261 can be made to transfer the third workpiece W to the transport pad 311 (step 121) and then transport the second workpiece W to the cassette 18 without delay (second half of step 116), thereby enabling efficient operation of the first transport mechanism 26.

[0103] In step 122, a machining process is performed to machine the third workpiece W using the machining unit 11. Although omitted in Figure 5, a top surface height measurement process may be performed prior to the machining process in step 122 using the top surface height measuring instrument 47. Alternatively, the outer circumference of the workpiece W may be imaged with a camera, or the outer circumference may be detected with a sensor to detect the coordinates of three points on the outer circumference of the workpiece W, the coordinates of the center of the workpiece W may be detected, and the amount of deviation between the center of the workpiece W and the rotation center of the chuck table 20 may be calculated. Once the machining of the third workpiece W is complete, the chuck table 20 is moved from the machining position to the loading / unloading position by the operation of the X-axis moving mechanism 21.

[0104] Figure 5 shows the processing steps up to step 122 for the third workpiece W. Furthermore, the same operations as those performed on the second workpiece W (steps 114 to 116) are carried out on the processed third workpiece W to clean it and store it in cassette 18. By repeating the same sequence of operations as described above for the second and third workpiece W, it is possible to process any number of workpieces W from the fourth workpiece onward.

[0105] When processing multiple workpieces W in succession, the control unit 15 sets and executes an operation sequence including the fluid supply process, as shown in the example in Figure 5 described above. This makes it possible to suppress differences in the amount of deformation of the chuck table 20 caused by differences in transport time, even if the transport time for each workpiece W from the cassette 18 to the chuck table 20 is different. This prevents the problem of different processing depths at the start and end of processing for multiple workpieces W.

[0106] In particular, the first workpiece W is transported from the cassette 18 to the chuck table 20 when the preceding workpiece W is not being held by the chuck table 20, whereas subsequent workpieces W are transported from the cassette 18 to the chuck table 20 when the preceding workpiece W is being held by the chuck table 20. Therefore, the transport time to the chuck table 20 differs depending on whether or not there is a waiting time (steps 109, 118) until the chuck table 20 becomes available. In the processing method of this embodiment, the processing from the fluid supply process in steps 101 and 102 to the holding process in step 103 and the processing process in step 104 for the first workpiece W, and the processing from the fluid supply process in steps 110 and 111 (119, 120) to the holding process in step 112 (121) and the processing process in step 113 (122) for the second and subsequent workpieces W, are performed at the same timing and with the same content (fluid supply at a timing as close as possible to the processing process, and generally common fluid supply time and supply amount), thereby making it possible to standardize the conditions regarding the thermal deformation of the chuck table 20 regardless of the difference in transport time for each workpiece W. As a result, it is possible to prevent processing defects caused by differences in the amount of deformation of the chuck table 20 for all workpieces W that are processed continuously, and to maintain a constant processing depth.

[0107] Figure 5 shows an example where the transport time for each workpiece W differs depending on whether or not a preceding workpiece W is held in the chuck table 20. However, the causes of differences in the transport time for each workpiece W are not limited to this. For example, if maintenance such as dressing the cutting blade 14 for sharpening or setting up to detect the height position of the tip of the cutting blade 14 is performed in the middle of processing multiple workpieces W, the processing operation and the supply of cutting fluid are stopped during this maintenance. As a result, the transport time to the chuck table 20 for the workpieces W to be processed when processing resumes after maintenance is longer, and differences in the amount of deformation of the chuck table 20 are more likely to occur. In such cases, by performing the fluid supply process at the timing shown in Figure 5 (immediately before the holding process and the processing process), it is possible to suppress differences in the amount of deformation of the chuck table 20 during the processing of each workpiece W and achieve the effect of keeping the processing depth (cutting depth of the cutting blade 14) constant.

[0108] Furthermore, some processing machines that cut a workpiece along a predetermined line to form a processing groove (kerf) are equipped with a kerf check function that checks the kerf after cutting along the predetermined line. Because the transport time of each workpiece to the chuck table differs depending on whether or not a kerf check is performed, differences in the amount of deformation of the chuck table are likely to occur. In such cases, by performing the fluid supply process at the timing shown in Figure 5 (immediately before the holding process and the processing process), it is possible to suppress differences in the amount of deformation of the chuck table and achieve the effect of keeping the processing depth constant.

[0109] Figure 5 shows an example of applying a processing method (first form shown in Figure 3) in which the fluid supply process is performed first and the holding process is performed afterwards when processing multiple workpieces W. However, it is also possible to apply a processing method (second form shown in Figure 4) in which the holding process is performed first and the fluid supply process is performed afterwards. In this case, it is basically possible to achieve this by reversing the order of the fluid supply process (steps 101 and 102 for the first workpiece W, steps 110 and 111 for the second workpiece W, and steps 119 and 120 for the third workpiece W) and the holding process (step 103 for the first workpiece W, step 112 for the second workpiece W, and step 121 for the third workpiece W) in the processing of each workpiece W in Figure 5. Regarding the first workpiece W, the order in which the workpiece removal process (step 100) is followed by the holding process (step 103) cannot be changed. Therefore, in actual processing, the timing of the holding process (step 103) remains the same as in Figure 5, and the fluid supply process (steps 101 and 102) is inserted between the holding process (step 103) and the machining process (step 104).

[0110] As described above, the processing apparatus 10 and processing method using the processing apparatus 10 of this embodiment prevent changes in the processing depth of the workpiece W due to thermal deformation of the chuck table 20. The processing apparatus 10 includes a top surface height measuring device 47 that measures the top surface height of the workpiece W without contact, and a fluid supply unit 50 that supplies water and air to the top surface of the chuck table 20 or the workpiece W before the top surface height is measured by the top surface height measuring device 47. The chuck table 20 is cooled by the heat of vaporization that dries the chuck table 20 by the supply of air from the fluid supply unit 50, thereby preventing the problem of the processing depth differing between the start and end of processing due to changes in the shape of the chuck table 20 when processing multiple workpieces W.

[0111] In this embodiment, the processing apparatus 10 has a water nozzle 51 and an air nozzle 54 of the fluid supply unit 50 positioned along the movement path (recess 22) in which the chuck table 20 moves between the loading / unloading position and the processing position. This allows for efficient fluid supply at a position close to the processing position before the processing step is performed at the processing position of the chuck table 20. In particular, in the second embodiment of the processing method shown in Figure 4, a holding step is performed at the loading / unloading position of the chuck table 20, then a fluid supply step is performed while the chuck table 20 is moved from the loading / unloading position to the processing position, and then the processing step is performed after it is moved to the processing position. Therefore, the operation up to the processing step can be performed with a simple movement of the chuck table 20, similar to existing processing methods that do not have a fluid supply step. Furthermore, since the water nozzle 51 and air nozzle 54 are positioned to traverse the recess 22 in the Y-axis direction, a space-efficient arrangement is achieved in the fluid supply unit 50, and fluid can be supplied to the entire chuck table 20 and workpiece W without leakage.

[0112] Note that the structure supporting the chuck table and the structure of the fluid supply unit may differ from those of the processing apparatus 10 in this embodiment. For example, a turntable that rotates about an axis in the Z-axis direction may be provided, and the chuck table may be mounted on the turntable. The rotation of the turntable positions the chuck table at the loading / unloading position and the processing position. In this case, the fluid supply unit is equipped with water nozzles and air nozzles extending in the radial direction of the turntable, and fluid can be supplied to the chuck table and workpiece with the rotation angle of the turntable set so that the chuck table is positioned below the water nozzles and air nozzles.

[0113] In this embodiment, the processing apparatus 10 trims the outer circumference of the workpiece W using a cutting blade 14 provided in the processing unit 11. However, as described above, the application of the present invention is not limited to such a processing apparatus 10, but can be broadly applied to processing apparatuses and processing methods that process a workpiece to a predetermined processing depth. In other words, if there is a type of processing apparatus or processing method in which a difference in the amount of deformation of the chuck table that holds the workpiece affects the processing depth of the workpiece and causes processing defects, the same effect as described above can be obtained by applying the present invention. Furthermore, the number of chuck tables provided in the processing apparatus is not limited to one, and may be provided with multiple chuck tables.

[0114] In this embodiment, the processing apparatus 10 is equipped with a water nozzle 51 and an air nozzle 54 of the fluid supply unit 50 at a location separate from the cutting water nozzles 44 and 45 provided by the processing unit 11. However, the supply of fluid (especially liquid) in the fluid supply process may be carried out by supplying cutting water (processing water) from the cutting water nozzles 44 and 45. Alternatively, the processing unit 11 may be equipped with an air nozzle instead of the air nozzle 54 in this embodiment.

[0115] Furthermore, the embodiments of the present invention are not limited to the embodiments and modifications described above, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea of ​​the present invention. Moreover, if the technical idea of ​​the present invention can be realized in a different way by advances in the art or by other derived arts, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea of ​​the present invention. [Industrial applicability]

[0116] According to the processing apparatus and processing method of the present invention, it is possible to prevent changes in the processing depth of the workpiece due to thermal deformation of the chuck table, thereby achieving highly accurate processing in various processing apparatuses that process a workpiece to a predetermined depth. [Explanation of symbols]

[0117] 10: Processing equipment 11: Processing Unit 14: Cutting blade 15: Control Unit 16: Cassette Stage 17: Lifting mechanism 18: Cassette 20: Chuck Table 21:X-axis movement mechanism 25: Rotating mechanism (machining feed unit) 26: First conveying mechanism (conveying mechanism) 27: Washing Unit 28: Spinner Table 30: Cleaning nozzle 31: Second conveying mechanism 36: Suction source 38:Y-axis movement mechanism 39:Z-axis movement mechanism 41: Spindle Housing 42: Spindle 44: Cutting fluid nozzle 45: Cutting fluid nozzle 46: Cutting water supply source 47: Top surface height measuring instrument 50:Fluid supply section 51: Water nozzle 52: Water supply source 54: Air nozzle 55: Air supply source 261: Robot Hand 311: Conveyor pad W: Work Wa: First wafer Wb: Second wafer

Claims

1. A machining apparatus comprising: a chuck table for holding a workpiece; a machining unit for machining the workpiece held on the chuck table to a predetermined depth from the top surface; a machining feed unit for relative machining feed between the chuck table and the machining unit; and a fluid supply unit for supplying fluid to the chuck table, A machining apparatus comprising a control unit that controls the machining unit and the machining feed unit so as to supply the fluid to the chuck table at a predetermined flow rate for a predetermined time before machining the workpiece.

2. The system comprises a cassette stage on which a cassette containing the workpiece is placed, and a transport mechanism that holds and transports the workpiece relative to the cassette placed on the cassette stage and the chuck table, The processing apparatus according to claim 1, wherein the control unit supplies the fluid to the chuck table until just before the workpiece held by the transport mechanism is transported to the chuck table.

3. A method for machining a workpiece using a machining apparatus comprising: a chuck table for holding a workpiece; a machining unit for machining the workpiece held on the chuck table from its top surface to a predetermined depth; a machining feed unit for relative machining feed between the chuck table and the machining unit; and a fluid supply unit for supplying fluid to the chuck table, wherein A fluid supply step of supplying the fluid to the chuck table at a predetermined flow rate for a predetermined time, After the fluid supply step, a holding step is performed to hold the workpiece on the chuck table, A machining process for processing the workpiece, A method for processing a workpiece, consisting of the following.

4. A method for machining a workpiece using a machining apparatus comprising: a chuck table for holding a workpiece; a machining unit for machining the workpiece held on the chuck table from its top surface to a predetermined depth; a machining feed unit for relative machining feed between the chuck table and the machining unit; and a fluid supply unit for supplying fluid to the chuck table, wherein A holding step of holding the workpiece in the chuck table, A fluid supply step of supplying the fluid to the workpiece held on the chuck table at a predetermined flow rate for a predetermined time, A machining process for processing the workpiece, A method for processing a workpiece, consisting of the following.

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