Conveyor pads and processing equipment

Abstract

To quickly detach a wafer from a holding surface of a chuck table.SOLUTION: According to an embodiment, by separating only an outer peripheral portion of a wafer 100 from a holding surface 22 of a chuck table 20 by a first outer peripheral suction part 91 of a carrier pad 80, the wafer 100 is made into the middle projection shape, and the atmospheric air is put into the holding surface 22 from the outer peripheral portion of the wafer 100 to break the vacuum of the holding surface 22. Therefore, the wafer 100 can be separated from the holding surface 22 even without jetting water and fluid mixture from the holding surface 22 by a fluid flow mechanism 46. Consequently, the wafer 100 can be quickly detached from the holding surface 22.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a transfer pad and a processing apparatus.

Background Art

[0002] As disclosed in Patent Documents 1 and 2, in a grinding apparatus, the lower surface of a wafer is sucked and held by the holding surface on the upper surface of the porous member of a chuck table, and the upper surface of the wafer is ground with a grindstone. Then, the upper surface of the ground wafer is sucked and held by a transfer pad, a mixed fluid of water and air is ejected from the chuck table, and the transfer pad holding the wafer is lifted from the holding surface to separate the wafer from the holding surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, when separating the wafer from the holding surface, the water of the mixed fluid ejected from the holding surface makes the wafer float from the holding surface, and the air of the mixed fluid breaks the surface tension of the water. That is, after the wafer is lifted from the holding surface by the ejection of the mixed fluid, the transfer pad holding the wafer is lifted to separate the wafer from the holding surface, and the wafer is transported to a cleaning apparatus. Therefore, it takes time until the wafer is separated from the holding surface.

[0005] Therefore, an object of the present invention is to quickly separate a wafer from the holding surface of a chuck table.

Means for Solving the Problems

[0006] The first transport pad of this grinding apparatus (first transport pad) is a transport pad arranged in a discharge mechanism that suction-holds the upper surface of a plate-shaped workpiece that is suction-held on the holding surface of a chuck table which is in communication with a first suction source, raises the plate-shaped workpiece from the holding surface which is cut off from communication with the first suction source, and discharges the plate-shaped workpiece from the holding surface, and comprises a base plate and an outer peripheral suction part arranged on the lower surface of the base plate which suction-holds the outer peripheral portion of the plate-shaped workpiece, The base plate comprises a central suction portion positioned inside the outer peripheral suction portion for suction holding the central portion of a plate-shaped workpiece, and an expandable portion positioned between the central suction portion and the base plate, wherein the central suction portion is suspended from the base plate with the expandable portion extended and positioned lower than the outer peripheral suction portion. .

[0007] The first processing device of this grinding apparatus comprises a chuck table that holds a plate-shaped workpiece by suction using a holding surface communicated with a first suction source, a processing mechanism for processing the plate-shaped workpiece held by suction on the holding surface of the chuck table, a discharge mechanism for discharge the plate-shaped workpiece from the chuck table, and a control unit, wherein the discharge mechanism comprises a first transport pad and a lifting mechanism for raising and lowering the first transport pad, and the control unit lowers the first transport pad using the lifting mechanism. The central suction part and The outer peripheral suction portion is brought into contact with the upper surface of the plate-shaped workpiece held on the holding surface; the outer peripheral suction portion is connected to a second suction source so that the outer peripheral portion of the upper surface of the plate-shaped workpiece is held by the outer peripheral suction portion while blocking communication between the holding surface and the first suction source; the lifting mechanism raises the first transport pad by a predetermined distance to make the plate-shaped workpiece into a convex shape, separating only the outer peripheral portion of the plate-shaped workpiece held by the outer peripheral suction portion from the holding surface, and allowing air to enter the holding surface to break the vacuum on the holding surface. By connecting the central suction section to the third suction source and using the central suction section to suck the central portion of the upper surface of the plate-shaped workpiece, the plate-shaped workpiece is made flat. The first transport pad is raised further to control the discharge of the plate-shaped workpiece from the holding surface. [Effects of the Invention]

[0010] By using this transport pad, the outer periphery suction section separates only the outer periphery of the plate-shaped workpiece from the holding surface of the chuck table, allowing air to enter the holding surface from the outer periphery of the plate-shaped workpiece and break the vacuum on the holding surface. Therefore, it is possible to separate the plate-shaped workpiece from the holding surface without spraying water or a mixed fluid from the holding surface. As a result, the plate-shaped workpiece can be quickly detached from the holding surface of the chuck table. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view showing the configuration of the grinding device. [Figure 2] This is an explanatory diagram showing the configuration of the unloading mechanism. [Figure 3] This is a perspective view showing the configuration of the transport pad. [Figure 4] This is an explanatory diagram showing the wafer transport operation by the unloading mechanism. [Figure 5] This is an explanatory diagram showing the wafer transport operation by the unloading mechanism. [Figure 6] This is an explanatory diagram showing the wafer transport operation by the unloading mechanism. [Figure 7] This is an explanatory diagram showing the wafer transport operation by the unloading mechanism. [Figure 8] This is a perspective view showing other components of the transport pad. [Figure 9] This is an explanatory diagram showing the wafer transport operation by the unloading mechanism. [Figure 10] This is an explanatory diagram showing the wafer transport operation by the unloading mechanism. [Figure 11] This is an explanatory diagram showing the wafer transport operation by the unloading mechanism. [Figure 12] This is an explanatory diagram showing the wafer transport operation by the unloading mechanism. [Modes for carrying out the invention]

[0012] As shown in FIG. 1, the grinding device 1 according to the present embodiment is an example of a processing device and is a device for grinding the wafer 100. The wafer 100 is an example of a plate-shaped workpiece and has a front surface 101 and a back surface 102. The back surface 102 of the wafer 100 is a surface to be processed for grinding.

[0013] The grinding device 1 has a first device base 10 and a second device base 11 disposed behind the first device base 10 (on the +Y direction side).

[0014] On the -Y direction side of the first device base 10, a first cassette stage 160 and a second cassette stage 162 are provided. A first cassette 161 for accommodating the wafer 100 before processing is placed on the first cassette stage 160. A second cassette 163 for accommodating the wafer 100 after processing is placed on the second cassette stage 162.

[0015] The first cassette 161 and the second cassette 163 are provided with a plurality of shelves inside, and one wafer 100 is accommodated on each shelf. That is, the first cassette 161 and the second cassette 163 accommodate a plurality of wafers 100 in a shelf-like manner.

[0016] The openings (not shown) of the first cassette 161 and the second cassette 163 face the +Y direction side. A robot 155 is disposed on the +Y direction side of these openings. The robot 155 has a holding surface for holding the wafer 100. The robot 155 carries (stores) the wafer 100 after processing into the second cassette 163. Also, the robot 155 takes out the wafer 100 before processing from the first cassette 161 and places it on the temporary placement table 154 of the temporary placement mechanism 152.

[0017] The temporary placement mechanism 152 is used to temporarily place the wafer 100 taken out from the first cassette 161 and is provided at a position adjacent to the robot 155. The temporary placement mechanism 152 has a temporary placement table 154 and an alignment member 153.

[0018] The alignment member 153 includes a plurality of alignment pins arranged outside so as to surround the temporary placement table 154, and a slider that moves the alignment pins in the radial direction of the temporary placement table 154. In the alignment member 153, when the alignment pins are moved toward the center in the radial direction of the temporary placement table 154, the circle connecting the plurality of alignment pins is reduced in diameter. As a result, the wafer 100 placed on the temporary placement table 154 is aligned (centered) at a predetermined position.

[0019] An input mechanism 170 is provided at a position adjacent to the temporary placement mechanism 152. The input mechanism 170 places the wafer 100 temporarily placed on the temporary placement mechanism 152 on the holding surface 22 of the chuck table 20 with the back surface 102 facing upward.

[0020] An opening 13 is provided on the upper surface side of the second device base 11. And a wafer holding mechanism 30 is arranged in the opening 13.

[0021] The wafer holding mechanism 30 includes a chuck table 20 having a holding surface 22 for holding the wafer 100, a chuck table base 29 that supports the chuck table 20, a drive unit 26 connected to the proximal end side of the chuck table base 29 via an endless belt 25, a support member 28 that supports the chuck table base 29, and a plurality of support columns 27 that support the support member 28.

[0022] The chuck table 20 comprises a porous member 21 and a frame 23 that houses the porous member 21 so that its upper surface is exposed. The upper surface of the porous member 21 is a holding surface 22 that holds the wafer 100 by suction. The holding surface 22 is connected to a first suction source 47 (see Figure 2) to hold the wafer 100 by suction. In this way, the chuck table 20 holds the wafer 100, which is a plate-shaped workpiece, by suction using the holding surface 22 which is connected to the first suction source 47. Furthermore, the frame surface 24, which is the upper surface of the frame 23, surrounds the holding surface 22 and is formed to be flush with the holding surface 22.

[0023] The drive unit 26 includes a motor and a drive pulley, and rotates the chuck table base 29 by rotating the endless belt 25. As a result, the chuck table 20, which is supported by the chuck table base 29, rotates around a table rotation axis that extends in the Z-axis direction so as to pass through the center of the holding surface 22.

[0024] A cover plate 39 is provided around the chuck table 20, which moves along the Y-axis direction with the chuck table 20. A bellows cover 12 that expands and contracts in the Y-axis direction is connected to the cover plate 39. Below the wafer holding mechanism 30, a Y-axis direction movement mechanism 40 is provided.

[0025] The Y-axis movement mechanism 40 moves the chuck table 20 and the grinding mechanism 70 relative to each other in the Y-axis direction parallel to the holding surface 22. In this embodiment, the Y-axis movement mechanism 40 is configured to move the chuck table 20 in the Y-axis direction relative to the grinding mechanism 70.

[0026] The Y-axis movement mechanism 40 comprises a pair of Y-axis guide rails 42 parallel to the Y-axis direction, a Y-axis movement table 45 that slides on the Y-axis guide rails 42, a Y-axis ball screw 43 parallel to the Y-axis guide rails 42, a Y-axis motor 44 connected to the Y-axis ball screw 43, and a holder 41 that holds these components.

[0027] The Y-axis movable table 45 is slidably mounted on the Y-axis guide rail 42. A nut (not shown) is fixed to the Y-axis movable table 45. A Y-axis ball screw 43 is screwed into this nut. The Y-axis motor 44 is connected to one end of the Y-axis ball screw 43.

[0028] In the Y-axis movement mechanism 40, the Y-axis motor 44 rotates the Y-axis ball screw 43, causing the Y-axis movement table 45 to move in the Y-axis direction along the Y-axis guide rail 42. The wafer holding mechanism 30 is mounted on the Y-axis movement table 45. Therefore, as the Y-axis movement table 45 moves in the Y-axis direction, the wafer holding mechanism 30, including the chuck table 20, also moves in the Y-axis direction.

[0029] In this embodiment, the wafer holding mechanism 30 is moved along the Y-axis direction by the Y-axis movement mechanism 40 between a wafer holding position on the -Y direction side for holding the wafer 100 on the holding surface 22 of the chuck table 20 and a grinding position on the +Y direction side for grinding the wafer 100 held on the holding surface 22.

[0030] Furthermore, a column 15 is erected on the +Y direction side of the second device base 11. A grinding mechanism 70 for grinding the wafer 100 and a grinding feed mechanism 60 are provided on the front surface of the column 15.

[0031] The grinding feed mechanism 60 moves the chuck table 20 and the grinding wheel 77 of the grinding mechanism 70 relative to each other in the Z-axis direction (grinding feed direction) perpendicular to the holding surface 22. In this embodiment, the grinding feed mechanism 60 is configured to move the grinding wheel 77 in the Z-axis direction relative to the chuck table 20.

[0032] The grinding feed mechanism 60 includes a pair of Z-axis guide rails 61 parallel to the Z-axis direction, a Z-axis moving table 63 that slides on the Z-axis guide rails 61, a Z-axis ball screw 62 parallel to the Z-axis guide rails 61, a Z-axis motor 64, a Z-axis encoder 65 for detecting the amount of rotation of the Z-axis ball screw 62, and a holder 66 attached to the Z-axis moving table 63. The holder 66 supports the grinding mechanism 70.

[0033] The Z-axis moving table 63 is slidably mounted on the Z-axis guide rail 61. A nut (not shown) is fixed to the Z-axis moving table 63. A Z-axis ball screw 62 is screwed into this nut. The Z-axis motor 64 is connected to one end of the Z-axis ball screw 62.

[0034] In the grinding feed mechanism 60, the Z-axis motor 64 rotates the Z-axis ball screw 62, causing the Z-axis moving table 63 to move in the Z-axis direction along the Z-axis guide rail 61. As a result, the holder 66 attached to the Z-axis moving table 63, and the grinding mechanism 70 supported by the holder 66, also move in the Z-axis direction along with the Z-axis moving table 63.

[0035] The Z-axis encoder 65 is rotated by the Z-axis motor 64 rotating the Z-axis ball screw 62, and can recognize the rotation angle of the Z-axis ball screw 62. The height recognition unit, which recognizes the height of the grinding mechanism 70, recognizes the number of rotations and the rotation angle of the Z-axis ball screw 62 recognized by the Z-axis encoder 65, and based on the recognition result, can detect the height position of the grinding wheel 77 of the grinding mechanism 70 as it moves in the Z-axis direction.

[0036] The grinding mechanism 70 is an example of a processing mechanism for processing a wafer 100, which is a plate-shaped workpiece held by suction on the holding surface 22 of the chuck table 20. The grinding mechanism 70 comprises a spindle housing 71 fixed to a holder 66, a spindle 72 rotatably held in the spindle housing 71, a spindle motor 73 for rotationally driving the spindle 72, a wheel mount 74 attached to the lower end of the spindle 72, and a grinding wheel 75 supported by the wheel mount 74.

[0037] The spindle housing 71 is held in the holder 66 so as to extend in the Z-axis direction. The spindle 72 extends in the Z-axis direction so as to be perpendicular to the holding surface 22 of the chuck table 20 and is rotatably supported in the spindle housing 71.

[0038] The spindle motor 73 is connected to the upper end of the spindle 72. This spindle motor 73 causes the spindle 72 to rotate around a rotation axis that extends in the Z-axis direction.

[0039] The wheel mount 74 is formed in a disc shape and is fixed to the lower end (tip) of the spindle 72. The wheel mount 74 supports the grinding wheel 75.

[0040] The grinding wheel 75 is formed such that its outer diameter is approximately the same as the outer diameter of the wheel mount 74. The grinding wheel 75 includes an annular wheel base 76 made of a metal material. Multiple grinding wheels 77 are fixed to the underside of the wheel base 76, arranged in an annular pattern around its entire circumference. The grinding wheels 77 are rotated by a spindle motor 73 together with a spindle 72 around their center axis to grind the back surface 102 of the wafer 100 held in the chuck table 20.

[0041] Furthermore, a thickness measuring instrument 67 is provided on the side of the opening 13 in the second device base 11.

[0042] The thickness measuring instrument 67 has a holding surface height gauge 68 and a top surface height gauge 69. The holding surface height gauge 68 measures the height of the holding surface 22 of the chuck table 20 by contacting its tip with the frame surface 24 of the frame 23, which is on the same plane as the holding surface 22 of the chuck table 20. The top surface height gauge 69 measures the top surface height of the wafer 100 by contacting its tip with the top surface of the wafer 100 held on the holding surface 22. The thickness measuring instrument 67 measures the thickness of the wafer 100 by calculating the difference between the measurement value of the holding surface height gauge 68 and the measurement value of the top surface height gauge 69.

[0043] After grinding, the wafer 100 is discharged by the discharge mechanism 172. The discharge mechanism 172 transports the wafer 100, which is held on the chuck table 20, to the spinner table 157 of the single-wafer spinner cleaning mechanism 156.

[0044] The spinner cleaning mechanism 156 is a spinner cleaning unit for cleaning the wafer 100. The spinner cleaning mechanism 156 includes a spinner table 157 for holding the wafer 100, and a nozzle 158 for spraying cleaning water and drying air toward the spinner table 157.

[0045] In the spinner cleaning mechanism 156, the spinner table 157 holding the wafer 100 rotates, and cleaning water is sprayed towards the wafer 100, so the wafer 100 is spinner cleaned. After that, drying air is blown onto the wafer 100 to dry it.

[0046] The wafer 100, cleaned by the spinner cleaning mechanism 156, is then loaded by the robot 155 into the second cassette 163 on the second cassette stage 162.

[0047] Furthermore, the grinding device 1 has a control unit 7 inside for controlling the grinding device 1. The control unit 7 is equipped with a CPU that performs calculations according to a control program, and a storage medium such as memory. The control unit 7 executes various processes and provides overall control over each component of the grinding device 1.

[0048] For example, the control unit 7 controls each of the above-mentioned components of the grinding apparatus 1 to perform a grinding process on the wafer 100.

[0049] Here, the fluid flow mechanism 46 will be explained using Figure 2. The fluid flow mechanism 46 is a mechanism for supplying a fluid, such as air, water, or a mixture of air and water, to the holding surface 22 of the chuck table 20, or for applying a suction force to the holding surface 22.

[0050] The fluid flow mechanism 46 includes a suction groove 403, a suction channel 470 connected to the suction groove 403, and a suction pipe 471 connected to the suction channel 470.

[0051] The suction groove 403 is provided on the bottom surface of the recess in the frame 23 of the chuck table 20 so as to be in contact with the lower surface of the porous member 21. The suction groove 403 is formed in a concentric circle shape with the center of the chuck table 20 as the center.

[0052] The suction channel 470 extends downward from the bottom surface of the suction groove 403 and is connected to the suction pipe 471. One end of the suction pipe 471 is in communication with the suction channel 470. The other end of the suction pipe 471 is connected to a first suction source 47. This first suction source 47 is equipped with a vacuum generating device such as a vacuum pump or ejector mechanism, and is in communication with the porous member 21 of the chuck table 20 and is used to apply suction force to the holding surface 22, which is its upper surface.

[0053] Furthermore, the suction piping 471 is equipped with a suction on / off valve 475 and a suction flow rate adjustment unit 473 in order from the first suction source 47 toward the suction flow path 470. The suction on / off valve 475 switches the communication state between the suction piping 471 and the first suction source 47. The suction flow rate adjustment unit 473 is, for example, a proportional control valve, and is used to adjust the suction force transmitted from the first suction source 47 to the holding surface 22 of the porous member 21 by changing the diameter of the internal orifice when the suction on / off valve 475 is open.

[0054] Furthermore, an air pipe 481 is connected to the suction pipe 471. The air pipe 481 is a pipe that connects the holding surface 22 of the chuck table 20 to the air supply source 48.

[0055] One end of the air pipe 481 is connected to the suction passage 470 via the suction pipe 471. The other end of the air pipe 481 is connected to an air supply source 48. The air supply source 48 is equipped with a compressor and is used to supply air to the holding surface 22 of the chuck table 20.

[0056] Furthermore, the air piping 481 is equipped with an air supply on-off valve 485 and an air adjustment unit 483 in order from the air supply source 48 toward the suction passage 470. The air supply on-off valve 485 switches the communication state between the air piping 481 and the air supply source 48. The air adjustment unit 483 is, for example, a proportional control valve, and is used to adjust the flow rate of air sent from the air supply source 48 to the holding surface 22 by changing the diameter of the internal orifice when the air supply on-off valve 485 is open.

[0057] Furthermore, a water pipe 491 is connected to the air pipe 481. The water pipe 491 is a pipe that connects the holding surface 22 of the chuck table 20 to the water supply source 49.

[0058] One end of the water pipe 491 is connected to the suction channel 470 via the air pipe 481 and the suction pipe 471. The other end of the water pipe 491 is connected to a water supply source 49. The water supply source 49 is equipped with a pump and is used to supply water to the holding surface 22 of the chuck table 20.

[0059] Furthermore, the water piping 491 is equipped with a water supply shut-off valve 495 and a water adjustment unit 493 in order from the water supply source 49 toward the suction passage 470. The water supply shut-off valve 495 switches the communication state between the water piping 491 and the water supply source 49. The water adjustment unit 493 is, for example, a proportional control valve, and is used to adjust the flow rate of water sent from the water supply source 49 to the holding surface 22 by changing the diameter of the internal orifice when the water supply shut-off valve 495 is open.

[0060] The suction flow rate adjustment unit 473, the air adjustment unit 483, and the water adjustment unit 493 may be needle valves or gate valves whose orifice diameters can be manually adjusted.

[0061] Next, the configuration of the unloading mechanism 172 will be described. The unloading mechanism 172 unloads the wafer 100 from the chuck table 20. Specifically, the unloading mechanism 172 uses suction to hold the upper surface of the wafer 100, which is held by suction on the holding surface 22 of the chuck table 20 which is in communication with the first suction source 47, and raises the wafer 100 from the holding surface 22, which is then cut off from communication with the first suction source 47, thereby unloading the wafer 100 from the holding surface 22.

[0062] As shown in Figure 2, the unloading mechanism 172 includes a disc-shaped transport pad 80, an arm 81 that suspends the transport pad 80 so as to be able to move up and down, a rotating column 82 extending in the Z-axis direction, and a moving mechanism 50 connected to the rotating column 82. The base end of the arm 81 is connected to the upper end of the rotating column 82. The moving mechanism 50 moves the rotating column 82 together with the arm 81 and the transport pad 80.

[0063] The moving mechanism 50 is an example of a lifting mechanism for raising and lowering the transport pad 80. The moving mechanism 50 includes a column 51 erected on the first device base 10 (see Figure 1), a ball screw 52 provided on the column 51, a guide rail 53 arranged parallel to the ball screw 52, ​​a motor 54 for rotating the ball screw 52, ​​an encoder 57 for detecting the amount of rotation of the ball screw 52 (e.g., number of rotations and rotation angle), and a nut 55 that is screwed onto the ball screw 52. A rotating column 82 is installed on the guide rail 53 in a slidable state. The rotating column 82 is also connected to the nut 55.

[0064] In the moving mechanism 50, the motor 54 rotates the ball screw 52 around a rotation shaft 521 extending in the Z-axis direction, thereby moving the rotating column 82 up and down in the Z-axis direction along the guide rail 53. By moving the rotating column 82 up and down in the Z-axis direction in this way, the arm 81 connected to the rotating column 82 and the transport pad 80 suspended from the arm 81 are moved up and down. At this time, the encoder 57 recognizes the amount of rotation of the ball screw 52 and, based on the recognition result, detects the height position of the transport pad 80 that is being moved up and down in the Z-axis direction.

[0065] Furthermore, the moving mechanism 50 is configured to allow the arm 81 to rotate around a rotation axis 821 in the Z-axis direction that passes through the rotating column 82. In this embodiment, the arm 81 can rotate together with the suspended transport pad 80 around the rotation axis 821 by a rotation motor (not shown).

[0066] In this way, the moving mechanism 50 allows the transport pad 80 to be moved by raising and lowering and rotating the arm 81, thereby adjusting the height and horizontal position of the transport pad 80.

[0067] A disc-shaped member 811 is formed at the tip end of the arm 81. Multiple (for example, three) through holes 812 are formed through the disc member 811 at equal intervals around its circumference. Bolts 84 connected to the transport pad 80 are inserted into the through holes 812.

[0068] The bolt 84 comprises a shaft portion 841 having a diameter slightly smaller than the through hole 812, and a head portion 842 formed at the upper end of the shaft portion 841.

[0069] The shaft portion 841 passes through the through hole 812 and is loosely fitted into the through hole 812. The lower end of the shaft portion 841 is connected to the upper surface of the base plate 90 of the transport pad 80. The head portion 842 is formed to be larger in diameter than the through hole 812, limiting the downward range of the bolt 84.

[0070] Furthermore, the bolt 84 has a spring 843 around its shaft portion 841, which acts as a shock-absorbing member. The upper end of the spring 843 is in contact with the lower surface of the disc member 811, while the lower end of the spring 843 is in contact with the upper surface of the base plate 90 of the transport pad 80. The spring 843 biases the disc member 811 and the transport pad 80 in a direction away from each other.

[0071] The arm 81 is capable of suspending the transport pad 80 while absorbing the impact applied to the transport pad 80 via the disc member 811 and bolt 84 configured in this way.

[0072] As shown in Figures 2 and 3, the transport pad 80 includes a disc-shaped base plate 90 and a first outer peripheral suction portion 91 and a first central suction portion 92 located on the lower surface 90a of the base plate 90.

[0073] The first outer peripheral suction portion 91 is an example of an outer peripheral suction portion and is a member for suction holding the outer peripheral portion of the wafer 100, and is formed, for example, in the shape of a suction cup. In this embodiment, four first outer peripheral suction portions 91 are arranged at equal intervals on a circle centered on the center of the lower surface 90a of the base plate 90 near the outer peripheral portion of the lower surface 90a.

[0074] The first central suction portion 92 is an example of a central suction portion and is located inside the first outer peripheral suction portion 91 on the base plate 90. The first central suction portion 92 is a member for suction holding the central portion of the wafer 100 and is formed, for example, in the shape of a suction cup. In this embodiment, three first central suction portions 92 are arranged at equal intervals on a circle centered on the center of the lower surface 90a of the base plate 90.

[0075] Furthermore, a first telescopic section 921 is positioned between the first central suction section 92 and the base plate 90. In other words, the first central suction section 92 is connected to the base plate 90 via the first telescopic section 921.

[0076] The first telescopic section 921 is an example of a telescopic section, and is formed in an expandable bellows-like shape and has spring properties. As shown in Figure 2, the first telescopic section 921 is extended downward due to the weight and spring properties of the first central suction section 92 and the first telescopic section 921. Therefore, the first central suction section 92 is suspended from the base plate 90 when the first telescopic section 921 is extended and is positioned lower than the first outer peripheral suction section 91. The first telescopic section 921 is also configured to contract when a suction force is applied to the first central suction section 92. When the first telescopic section 921 is contracted, the first central suction section 92 is positioned at the same height as the first outer peripheral suction section 91.

[0077] Furthermore, as shown in Figure 2, the discharge mechanism 172 has an outer suction passage 93 and an inner suction passage 96. The lower end of the outer suction passage 93 is branched into four, passing through the base plate 90 and connected to four first outer peripheral suction sections 91. The upper end of the outer suction passage 93 is connected to a second suction source 95 via an outer air valve 94.

[0078] Furthermore, the inner suction passage 96 is located within the base plate 90 via a suction passage 89 that penetrates the center of the disc member 811. The lower end of the inner suction passage 96 branches into three within the base plate 90 and is connected to three first central suction sections 92. The upper end of the inner suction passage 96 is connected to a third suction source 98 via an inner air valve 97.

[0079] Therefore, in the unloading mechanism 172, by opening the outer air valve 94, the second suction source 95 is connected to the first outer peripheral suction section 91, providing suction force to the first outer peripheral suction section 91, making it possible to hold the outer peripheral portion of the wafer 100 on the holding surface 22 by suction. Also, by opening the inner air valve 97, the third suction source 98 is connected to the first central suction section 92, providing suction force to the first central suction section 92, making it possible to hold the central portion of the wafer 100 on the holding surface 22 by suction.

[0080] Then, by rotating and raising / lowering the rotating column 82 and arm 81 using the moving mechanism 50, the transport pad 80 holding the wafer 100 can be rotated and raised / lowered, allowing the wafer 100 to be removed from the chuck table 20.

[0081] Next, a method for transporting the wafer 100 using the transport mechanism 172 having the above configuration will be described. The transport of the wafer 100 by the transport mechanism 172 is performed by the control unit 7 after the grinding of the wafer 100 using the grinding mechanism 70 (see Figure 1) is completed. At this time, the suction valve 475 of the fluid flow mechanism 46 is open, and the holding surface 22 of the chuck table 20 is in communication with the first suction source 47, holding the wafer 100 by suction. The outer air valve 94 and the inner air valve 97 are closed.

[0082] After grinding of the wafer 100 is complete, the control unit 7 controls the Y-axis movement mechanism 40 shown in Figure 1 to move the chuck table 20 holding the wafer 100 from the grinding position below the grinding mechanism 70 to the wafer holding position on the -Y side, closer to the discharge mechanism 172.

[0083] Subsequently, the grinding mechanism 70 rotates the rotating column 82 and arm 81 by the moving mechanism 50 in the unloading mechanism 172, thereby positioning the transport pad 80 above the wafer 100, which is held by suction on the holding surface 22 of the chuck table 20, as shown in Figure 2. At this time, the control unit 7 adjusts the positional relationship between the center of the base plate 90 on the transport pad 80 and the center of the back surface 102, which is the upper surface of the wafer 100, so that their horizontal positions are approximately aligned.

[0084] Next, the control unit 7 lowers the transport pad 80 suspended from the tip of the arm 81 by lowering the rotating column 82 using the moving mechanism 50. As a result, the control unit 7 brings the first outer peripheral suction portion 91 and the first central suction portion 92 of the transport pad 80 into contact with the back surface 102 of the wafer 100, as shown in Figure 4. Specifically, the control unit 7 brings the first outer peripheral suction portion 91 into contact with the outer peripheral portion of the back surface 102 of the wafer 100 held by the holding surface 22. The control unit 7 also brings the first central suction portion 92 into contact with the central portion of the back surface 102 of the wafer 100. At this time, as the first central suction portion 92 is pressed against the central portion of the back surface 102 of the wafer 100, the first telescopic portion 921 supporting the first central suction portion 92 becomes contracted.

[0085] Then, the control unit 7 opens the outer air valve 94 in this state, connecting the first outer peripheral suction unit 91 to the second suction source 95, and using the first outer peripheral suction unit 91 to suck and hold the outer peripheral portion of the back surface 102 of the wafer 100. Furthermore, the control unit 7 closes the suction on / off valve 475 of the fluid flow mechanism 46, thereby blocking communication between the holding surface 22 of the chuck table 20 and the first suction source 47.

[0086] Next, the control unit 7 raises the arm 81 and the transport pad 80 by a predetermined distance by raising the rotating column 82 using the moving mechanism 50. As a result, the base plate 90 is raised by a predetermined distance, and as shown in Figure 5, the first outer peripheral suction part 91, which holds the outer peripheral portion of the back surface 102 of the wafer 100, is raised by a predetermined distance. Therefore, the outer peripheral portion of the wafer 100 is separated from the holding surface 22.

[0087] On the other hand, the first telescopic section 921 supporting the first central suction section 92 extends downward as the base plate 90 rises, due to the weight of the first central suction section 92 and the first telescopic section 921, as well as the springiness of the first telescopic section 921. As a result, the first central suction section 92, which is in contact with the central part of the back surface 102 of the wafer 100, presses the wafer 100 downward, so that the central part of the wafer 100 remains in contact with the holding surface 22. Consequently, the wafer 100 takes on a convex shape with the center protruding downward, as shown in Figure 5.

[0088] Therefore, in the wafer 100, only the outer peripheral portion held by the first outer peripheral suction portion 91 is separated from the holding surface 22. As a result, air is introduced from the outer peripheral portion of the wafer 100 to the holding surface 22, and the vacuum on the holding surface 22 is broken. In other words, the vacuum within the porous member 21 that constitutes the holding surface 22 is broken.

[0089] In this way, the control unit 7 raises the transport pad 80 by a predetermined distance using the moving mechanism 50, thereby creating a convex shape in the center of the wafer 100, separating only the outer peripheral portion of the wafer 100 that is being held by the first outer peripheral suction unit 91 from the holding surface 22, and allowing air to enter the holding surface 22 to break the vacuum on the holding surface 22. As a result, the suction force from the holding surface 22 to the wafer 100 disappears, making it possible to easily separate the wafer 100 from the holding surface 22.

[0090] Next, as shown in Figure 6, the control unit 7 uses the moving mechanism 50 to further raise the transport pad 80, completely separating the wafer 100 from the holding surface 22, and then removes the wafer 100 from the holding surface 22.

[0091] As described above, in this embodiment, the first outer peripheral suction portion 91 of the transport pad 80 separates only the outer peripheral portion of the wafer 100 from the holding surface 22, thereby creating a convex shape for the wafer 100, allowing air to enter the holding surface 22 from the outer peripheral portion of the wafer 100 and breaking the vacuum of the holding surface 22. Therefore, it is possible to separate the wafer 100 from the holding surface 22 without ejecting water or a mixed fluid from the holding surface 22 by the fluid flow mechanism 46. As a result, the wafer 100 can be quickly detached from the holding surface 22. Furthermore, it is possible to prevent the wafer 100 from getting wet.

[0092] In this embodiment, when the outer peripheral portion of the wafer 100 is separated from the holding surface 22 by the first outer peripheral suction section 91 (see Figure 5), or when the transport pad 80 holding the wafer 100 is completely separated from the holding surface 22 by the moving mechanism 50 (see Figure 6), the air supply on / off valve 485 of the fluid flow mechanism 46 may be opened to connect the holding surface 22 to the air supply source 48, thereby blowing air out from the holding surface 22. This makes it easy to separate the wafer 100 from the holding surface 22.

[0093] Furthermore, the first telescopic section 921 supporting the first central suction section 92 does not need to have spring properties. In this case, when the first outer peripheral suction section 91, which holds the outer peripheral portion of the back surface 102 of the wafer 100, rises by a predetermined distance, the first telescopic section 921 extends downward due to the weight of the first central suction section 92 and the first telescopic section 921, giving the wafer 100 a convex shape. Therefore, even in this configuration, only the outer peripheral portion of the wafer 100 is separated from the holding surface 22, air is introduced from the outer peripheral portion to the holding surface 22, and the vacuum of the holding surface 22 is broken.

[0094] Furthermore, the transport pad 80 does not necessarily have a first central suction section 92 and a first expandable section 921. In this case, when the first peripheral suction section 91, which holds the outer peripheral portion of the back surface 102 of the wafer 100, rises by a predetermined distance, the unheld central portion of the wafer 100 sags downward due to its own weight, causing the wafer 100 to take on a convex shape. Therefore, even in this configuration, only the outer peripheral portion of the wafer 100 is separated from the holding surface 22, and air is introduced from the outer peripheral portion to the holding surface 22, breaking the vacuum on the holding surface 22.

[0095] Furthermore, in this embodiment, the grinding apparatus 1 includes a first suction source 47 connected to the holding surface 22 of the chuck table 20, a second suction source 95 connected to the first outer peripheral suction section 91 of the transport pad 80, and a third suction source 98 connected to the first central suction section 92. In this regard, the first suction source 47, the second suction source 95, and the third suction source 98 may each be separate suction sources, or they may be one or two common suction sources.

[0096] Furthermore, in this embodiment, the control unit 7 may, after separating the outer peripheral portion of the wafer 100 from the holding surface 22 and breaking the vacuum of the holding surface 22, and then completely separating the transport pad 80 holding the wafer 100 from the holding surface 22 using the moving mechanism 50, open the inner air valve 97 to connect the first central suction unit 92 to the third suction source 98, as shown in Figure 7, and use the first central suction unit 92 to suck the central portion of the back surface 102 of the wafer 100. As a result, the first expandable / contractible unit 921 supporting the first central suction unit 92 contracts, and the wafer 100 becomes flat.

[0097] Then, in this state, the control unit 7 further raises the transport pad 80 with the moving mechanism 50 to completely separate the wafer 100 from the holding surface 22 and removes the wafer 100 from the holding surface 22. In this case, the wafer 100 is held in a flat state by both the first outer peripheral suction section 91 and the first central suction section 92, making it possible to transport the wafer 100 in a stable state.

[0098] Furthermore, as shown in Figure 8, the transport pad 80 may have a second outer periphery suction section 111 and a second central suction section 112 instead of the first outer periphery suction section 91 and the first central suction section 92.

[0099] The second outer peripheral suction portion 111 is an example of an outer peripheral suction portion and is a member for suction and holding the outer peripheral portion of the wafer 100. The second outer peripheral suction portion 111 is positioned near the outer peripheral portion on the lower surface 90a of the base plate 90. The second outer peripheral suction portion 111 is made of, for example, an annular porous material and has a downward-facing first suction surface 110. This first suction surface 110 is formed, for example, to be flush with the lower surface 90a of the base plate 90. The second outer peripheral suction portion 111 can communicate with the second suction source 95 via the outer suction passage 93 and outer air valve 94 described above.

[0100] The second central suction portion 112 is an example of a central suction portion and is located inside the second outer peripheral suction portion 111 on the base plate 90. The second central suction portion 112 is a member for suction holding the central portion of the wafer 100 and is formed as a disc-shaped suction pad having a downward-facing second suction surface 113 made of porous material. In this embodiment, the second central suction portion 112 has a shape that fits into a recess 901 formed in the center of the base plate 90 and is suspended from a plurality of second expandable portions 114 attached to the upper surface of this recess 901. Furthermore, the second central suction section 112 can be connected to the third suction source 98 via the inner suction passage 96 and inner air valve 97 described above.

[0101] The second telescopic section 114 is an example of a telescopic section and is formed in a spring-like shape that can expand and contract. The second telescopic section 114 is extended downward due to the weight and springiness of the second central suction section 112 and the second telescopic section 114. Therefore, the second central suction section 112 is suspended from the base plate 90 with the second telescopic section 114 extended and is positioned lower than the second outer peripheral suction section 111. The second telescopic section 114 is also configured to contract when a suction force is applied to the second central suction section 112. When the second telescopic section 114 contracts, the second central suction section 112 is housed in the recess 901 of the base plate 90 and is positioned at the same height as the second outer peripheral suction section 111. That is, the second suction surface 113 of the second central suction section 112 is at the same height as the first suction surface 110 of the second outer peripheral suction section 111 (flush with the lower surface 90a of the base plate 90).

[0102] In this configuration, when removing the wafer 100 from the holding surface 22 of the chuck table 20, the control unit 7 controls the moving mechanism 50 as described above to position the transport pad 80 above the wafer 100 which is being held by suction on the holding surface 22 of the chuck table 20, as shown in Figure 8.

[0103] Next, the control unit 7 lowers the transport pad 80 using the moving mechanism 50. As a result, as shown in Figure 9, the control unit 7 brings the first suction surface 110 of the second outer periphery suction part 111 and the second suction surface 113 of the second central suction part 112 into contact with the back surface 102 of the wafer 100. That is, the control unit 7 brings the second outer periphery suction part 111 of the transport pad 80 into contact with the outer periphery of the back surface 102 of the wafer 100 held by the holding surface 22. The control unit 7 also brings the second central suction part 112 into contact with the central part of the back surface 102 of the wafer 100. At this time, as the second central suction part 112 is pressed against the central part of the back surface 102 of the wafer 100, the second expandable part 114 supporting the second central suction part 112 contracts, and the second central suction part 112 is housed within the recess 901 of the base plate 90.

[0104] Then, the control unit 7 opens the outer air valve 94 in this state, connecting the second outer peripheral suction unit 111 to the second suction source 95, and using the second outer peripheral suction unit 111 to suck and hold the outer peripheral portion of the back surface 102 of the wafer 100. Furthermore, the control unit 7 closes the suction on / off valve 475 of the fluid flow mechanism 46, thereby blocking communication between the holding surface 22 of the chuck table 20 and the first suction source 47.

[0105] Next, the control unit 7 raises the transport pad 80 by a predetermined distance using the moving mechanism 50. As a result, the base plate 90 rises by a predetermined distance, and the second outer peripheral suction part 111, which holds the outer peripheral portion of the back surface 102 of the wafer 100, rises by a predetermined distance, as shown in Figure 10. Consequently, the outer peripheral portion of the wafer 100 is separated from the holding surface 22.

[0106] On the other hand, the second telescopic part 114 supporting the second central suction part 112 extends downward as the base plate 90 rises, due to the weight of the second central suction part 112 and the second telescopic part 114, as well as the springiness of the second telescopic part 114. As a result, the second central suction part 112, which is in contact with the central part of the back surface 102 of the wafer 100, presses the wafer 100 downward, so that the central part of the wafer 100 remains in contact with the holding surface 22. Consequently, the wafer 100 takes on a convex shape with the center protruding downward, as shown in Figure 10.

[0107] Therefore, in wafer 100, only the outer peripheral portion held by the second outer peripheral suction section 111 is separated from the holding surface 22. As a result, air is introduced from the outer peripheral portion to the holding surface 22, and the vacuum on the holding surface 22 is broken.

[0108] Next, as shown in Figure 11, the control unit 7 uses the moving mechanism 50 to further raise the transport pad 80, completely separating the wafer 100 from the holding surface 22, and then removes the wafer 100 from the holding surface 22.

[0109] Thus, even with this configuration, the second outer peripheral suction section 111 of the transport pad 80 separates only the outer peripheral portion of the wafer 100 from the holding surface 22, thereby creating a convex shape for the wafer 100. This allows air to enter the holding surface 22 from the outer peripheral portion of the wafer 100, breaking the vacuum on the holding surface 22. Therefore, it is possible to separate the wafer 100 from the holding surface 22 without the fluid flow mechanism 46 ejecting water or a mixed fluid from the holding surface 22. As a result, the wafer 100 can be quickly detached from the holding surface 22. Furthermore, it is possible to prevent the wafer 100 from getting wet.

[0110] In this configuration as well, when separating the outer periphery of the wafer 100 or the entire wafer 100 from the holding surface 22, air may be ejected from the holding surface 22.

[0111] Furthermore, even in this configuration, the control unit 7 may, as shown in Figure 12, open the inner air valve 97 to connect the second central suction unit 112 to the third suction source 98 when separating the outer periphery of the wafer 100 from the holding surface 22 and breaking the vacuum of the holding surface 22, and then completely separating the transport pad 80 from the holding surface 22 with the moving mechanism 50, thereby sucking the central portion of the back surface 102 of the wafer 100 with the second central suction unit 112. As a result, the second expandable / contractible unit 114 supporting the second central suction unit 112 contracts, and the wafer 100 becomes flat.

[0112] Then, in this state, the control unit 7 further raises the transport pad 80 with the moving mechanism 50 to completely separate the wafer 100 from the holding surface 22 and removes the wafer 100 from the holding surface 22. Even in this case, the wafer 100 is held in a flat state by both the second outer peripheral suction section 111 and the second central suction section 112, making it possible to transport the wafer 100 in a stable state.

[0113] Furthermore, in this configuration, the second telescopic portion 114 supporting the second central suction portion 112 does not necessarily have to have spring properties. Furthermore, the second expandable portion 114 may not be provided. In this case, the second central suction portion 112 may be fixed to the base plate 90 such that the second suction surface 113 protrudes below the lower surface 90a of the base plate 90. In this case, it becomes easier to make the wafer 100 have a convex shape. Furthermore, the transport pad 80 does not necessarily have to include the first central suction section 92 and the second central suction section 112. The transport pad 80 may only have the first outer peripheral suction section 91 and the second outer peripheral suction section 111, and transport the wafer 100 held on the holding surface by suction only on its outer periphery. In other words, the wafer 100 may be made into a downward convex shape by the suction force remaining on the holding surface 22.

[0114] The processing apparatus according to this embodiment is not limited to a grinding apparatus, but can be any processing apparatus, as long as it includes a chuck table 20 that holds a plate-shaped workpiece by a holding surface 22, a processing mechanism for processing the plate-shaped workpiece held by the chuck table 20, and a discharge mechanism 172 equipped with a transport pad 80. For example, the processing apparatus may be a polishing apparatus having a polishing mechanism as a processing mechanism, or a cutting apparatus having a cutting mechanism as a processing mechanism. [Explanation of Symbols]

[0115] 1: Grinding device, 7: Control unit, 10: First device base, 11: Second device base, 12: Bellows cover, 13: Opening, 15: Column, 20: Chuck table, 21: Porous member, 22: Holding surface, 23: Frame, 24: Frame surface, 25: Endless belt, 26: Drive unit, 27: Support column, 28: Support member, 29: Chuck table base, 30: Wafer holding mechanism, 39: Cover plate, 40: Y-axis movement mechanism, 41: holding base, 42: Y-axis guide rail, 43: Y-axis ball screw, 44: Y-axis motor, 45: Y-axis moving table, 46: Fluid flow mechanism, 47: First suction source, 48: Air supply source, 49: Water supply source, 50: Moving mechanism, 51: Column, 52: Ball screw, 53: Guide rail, 54: Motor, 55: Nut, 57: Encoder, 60: Grinding feed mechanism, 61: Z-axis guide rail, 62: Z-axis ball screw, 63: Z-axis moving table, 64: Z-axis motor, 65: Z-axis encoder, 66: Holder, 67: Thickness measuring instrument, 68: Holding surface height gauge, 69: Top surface height gauge, 70: Grinding mechanism, 71: Spindle housing, 72: Spindle, 73: Spindle motor, 74: Wheel mount, 75: Grinding wheel, 76: Wheel base, 77: Grinding wheel, 80: Conveyor pad, 81: Arm, 82: Rotating column section, 84: Bolt, 89: Suction channel, 90: Base plate, 90a: Bottom surface, 91: first outer suction section, 92: first central suction section, 93: outer suction path, 94: Outer air valve, 95: Second suction source, 96: Inner suction passage, 97: Internal air valve, 98: Third suction source, 100: Wafer, 101: Surface, 102: back surface, 110: first suction surface, 111: second outer suction section, 112: Second central suction section, 113: Second suction surface, 114: Second telescopic section, 152: Temporary placement mechanism, 153: Alignment member, 154: Temporary placement table, 155: Robot, 156: Spinner cleaning mechanism, 157: Spinner table, 158: Nozzle, 160: First cassette stage, 161: First cassette, 162: Second cassette stage, 163: Second cassette, 170: Loading mechanism, 172: Export mechanism, 403: Suction groove, 470: Suction channel, 471: Suction piping, 473: Suction flow rate adjustment unit, 475: Suction on / off valve, 481: Air piping, 483: Air adjustment unit, 485: Air supply shut-off valve, 491: Water piping, 493: Water adjustment unit, 495: Water supply shut-off valve, 521: Rotating shaft, 811: Disc member, 812: Through hole, 821: Rotating shaft, 841: Shaft part, 842: Head, 843: Spring, 901: Recess, 921: First extension section

Claims

1. A transport pad is provided for a transport mechanism that uses suction to hold the upper surface of a plate-shaped workpiece that is held by suction on a holding surface of a chuck table connected to a first suction source, to lift the plate-shaped workpiece from the holding surface from which communication with the first suction source is blocked, and to transport the plate-shaped workpiece away from the holding surface. Base plate and The base plate is positioned on the lower surface and includes an outer periphery suction section that holds the outer periphery of a plate-shaped workpiece by suction, A central suction portion, positioned inside the outer peripheral suction portion of the base plate, which suctions and holds the central portion of the plate-shaped workpiece, It comprises a central suction part and an expandable part positioned between the base plate, The central suction section is suspended from the base plate with its extendable section in an extended state and is positioned lower than the outer periphery suction section. Transport pad.

2. A processing apparatus comprising: a chuck table that holds a plate-shaped workpiece by suction using a holding surface communicated with a first suction source; a processing mechanism for processing the plate-shaped workpiece held by suction on the holding surface of the chuck table; a discharge mechanism for discharging the plate-shaped workpiece from the chuck table; and a control unit, The discharge mechanism comprises a transport pad as described in claim 1 and a lifting mechanism for raising and lowering the transport pad. The control unit is The lifting mechanism lowers the transport pad, bringing the central suction portion and the outer peripheral suction portion into contact with the upper surface of the plate-shaped workpiece held on the holding surface. The outer peripheral suction portion is connected to the second suction source, and the outer peripheral portion of the upper surface of the plate-shaped workpiece is held in place by the outer peripheral suction portion, while the communication between the holding surface and the first suction source is blocked. The lifting mechanism raises the transport pad by a predetermined distance, causing the plate-shaped workpiece to take on a convex shape, separating only the outer periphery of the plate-shaped workpiece held by the outer periphery suction section from the holding surface, and allowing air to enter the holding surface to break the vacuum on the holding surface. By connecting the central suction section to a third suction source and using the central suction section to suck the central portion of the upper surface of the plate-shaped workpiece, the plate-shaped workpiece is made flat. Further raising the transport pad to unload the plate-shaped workpiece from the holding surface, and controlling the process, Processing equipment.

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