JP6301728B2 - Transport device - Google Patents

Description

  The present invention relates to a transfer device that holds and transfers an outer peripheral portion of a wafer.

  In recent years, with the thinning and miniaturization of electrical equipment, it is desired to make the wafer thinner. In addition, chamfering is performed on the outer periphery of the wafer to prevent cracking and dust generation during the manufacturing process. For this reason, when the thickness of the wafer is ground and finished to, for example, 100 μm or less, the outer periphery of the chamfered wafer becomes a knife edge, and there is a problem that the wafer is broken due to chipping from the outer peripheral side. In order to solve this problem, a method of removing (trimming) a chamfered portion that can become a knife edge after thinning of the wafer from the outer peripheral portion of the wafer prior to grinding is proposed (for example, see Patent Document 1). .

  In the processing method described in Patent Document 1, a wafer is held on a chuck table, and the surface side of the wafer is cut with a cutting blade. For this reason, it is necessary to carry the wafer with the wafer surface facing upward on the chuck table. Generally, since a device is formed on the surface of the wafer, there is a risk that the surface of the wafer may be damaged if the surface is held by the suction pad during the transfer of the wafer, such as vacuum suction transfer. For this reason, an edge clamp type transfer device that can transfer a wafer without touching the surface of the wafer is used (see, for example, Patent Document 2).

JP 2000-173961 A JP 2012-064872 A

  By the way, in the case of a bonded wafer, the resin for bonding sticks out from the outer periphery of the wafer by several μm to several tens of μm, resulting in variations in the outer diameter of the wafer, or in the case of a fully trimmed wafer. The outer diameter of the wafer varies depending on the width at which the outer peripheral portion of the wafer is removed. When such a wafer is transported by the edge clamp type transport device described in Patent Document 2, there is a risk that the transport device itself may malfunction or the outer periphery of the wafer may be damaged when the wafer is clamped. It was. Further, every time a conveyance error occurs, the clamp position (action position) has to be finely adjusted, and the work becomes complicated.

  The present invention has been made in view of the above points, and an object thereof is to provide a transfer device that can appropriately transfer a wafer in which the outer diameter varies and a wafer whose outer diameter has changed by processing. And

  A transport apparatus according to the present invention is a transport apparatus that transports a wafer, including a holding unit that holds an outer peripheral portion of a wafer, and a moving unit that moves the holding unit in a vertical direction and a horizontal direction. A plurality of claw members arranged in an annular shape to hold the outer peripheral portion of the wafer, a standby position where the plurality of claw members are separated from the outer peripheral portion of the wafer, and the plurality of claw members approach each other in the radial direction. A claw member moving unit that moves the plurality of claw members independently in the radial direction between the operation positions that hold the outer peripheral portion, and a claw member moving unit that approaches each of the plurality of claw members. A non-contact sensor that is arranged with a detection surface facing in a direction and detects a side surface of the outer peripheral portion of the wafer, and a control portion that controls the claw member moving portion, and the control portion holds the outer peripheral portion of the wafer. When you are out of the wafer Each of the claw member moving parts is controlled so that the plurality of claw members positioned at the standby position outside the part approach the outer peripheral part of the wafer, and the non-contact sensor is arranged on the side surface of the outer peripheral part of the wafer. When the movement is detected, the movement of each claw member moving portion is stopped and set to the action position.

  According to this configuration, when the plurality of claw members are independently moved so as to approach in the radial direction and the outer peripheral side surface of the wafer is detected by the non-contact sensor provided in each claw member, The movement is stopped. Since each claw member is stopped at a certain distance from the side surface of the outer peripheral portion of the wafer, even when the outer diameter of the wafer varies, the plurality of claw members are appropriately positioned at good working positions. Since each claw member does not come off from the outer peripheral portion of the wafer and does not abut each claw member against the side surface of the outer peripheral portion of the wafer, there is no need to adjust the operation position. Therefore, the wafer can be appropriately and continuously conveyed without generating a complicated operation.

  According to the present invention, the plurality of claw members provided with the non-contact type sensor are independently moved, and the position of each claw member when the outer peripheral side surface of the wafer is detected by the non-contact type sensor is set as the operation position. The wafer can be appropriately transported in response to variations in the outer diameter of the wafer.

It is an upper surface schematic diagram of the processing apparatus which concerns on this Embodiment. It is a perspective view of the conveying apparatus which concerns on this Embodiment. It is a figure which shows an example of the conveyance operation of the conveying apparatus which concerns on this Embodiment.

  Hereinafter, with reference to the attached drawings, a processing apparatus provided with a transfer apparatus of the present embodiment will be described. FIG. 1 is a schematic top view of the processing apparatus according to the present embodiment. In the following description, a configuration in which the transfer apparatus of the present invention is applied to a processing apparatus that performs full trimming on the outer peripheral edge of the wafer will be described, but the present invention is not limited to this configuration. The transfer device of the present invention may be applied to a processing device that half trims the outer peripheral edge of a wafer. Further, the transfer device may be used in other processing devices such as a grinding device and a laser processing device, or may be a device that transfers a wafer between the processing devices.

  As shown in FIG. 1, the processing apparatus 1 is a full-auto type processing apparatus, and performs a series of operations including a carry-in process, a cutting process, a cleaning process, and a carry-out process on a disk-shaped wafer W fully automatically. It is configured as follows. A chamfer 91 (see FIG. 3A) for preventing cracks and dust generation during the manufacturing process is formed on the outer peripheral edge of the wafer W. Further, a notch 92 indicating a crystal orientation is formed on the outer peripheral portion of the wafer W. The wafer W may be a semiconductor wafer in which devices such as IC and LSI are formed on a semiconductor substrate such as silicon or gallium arsenide, or an optical device such as an LED is formed on a ceramic, glass or sapphire inorganic material substrate. An optical device wafer may be used.

  In the processing apparatus 1, a carry-in area A1 is set in front of the apparatus, a processing area A2, a carry-in area A1, and a cleaning area A3 are set in the back of the apparatus adjacent to the processing area A2. A pair of cassette tables 13 and 14 are provided on the front surface 12 of the processing apparatus 1 so as to protrude forward from the carry-in area A1. On the cassette stand 13, a loading cassette C1 in which a wafer W before processing is accommodated is placed. An unloading cassette C2 in which the processed wafer W is accommodated is placed on the cassette table 14. The cassette table 13 functions as a carry-in port for the processing apparatus 1, and the cassette table 14 functions as a carry-out port for the processing apparatus 1.

  In the loading / unloading area A1, a loading / unloading arm 21 for loading / unloading the wafer W to / from the loading cassette C1 and the loading cassette C2 is provided. The carry-in / out arm 21 includes a multi-node link portion 22 composed of a plurality of arms and a hand portion 23 provided at the tip of the multi-node link portion 22. The multi-node link unit 22 is configured to be able to move the hand unit 23 in the vertical direction (Z-axis direction) and the horizontal direction (XY direction). Further, the multi-node link portion 22 is attached to a slide head of a linear motor type moving mechanism 24 and is configured to be movable in the X-axis direction by electromagnetic force. The loading / unloading arm 21 loads the unprocessed wafer W from the loading cassette C1 to the processing area A2 and unloads the processed wafer W from the cleaning area A3 to the unloading cassette C2.

  The processing area A2 is provided with a center position detecting means 26 for detecting the center position of the wafer W before processing, and a cutting mechanism 41 for cutting the outer peripheral portion of the surface of the wafer W on the chuck table 31. The center position detecting means 26 is provided with a centering table 27, and the center position of the wafer W is detected on the centering table 27. A chuck table 31 that reciprocates in the X-axis direction between the loading position of the wafer W and the cutting position is provided behind the centering table 27. On the base 11, an opening 17 extending in the X-axis direction along the movement locus of the chuck table 31 is formed.

  The opening 17 is covered with a bellows-shaped waterproof cover 18, and a ball screw type chuck table moving mechanism (not shown) for reciprocating the chuck table 31 in the X-axis direction is provided below the waterproof cover 18. Yes. On the surface of the chuck table 31, a holding surface 32 for adsorbing the wafer W by a porous material is formed. The holding surface 32 is connected to a suction source (not shown) through a flow path in the chuck table 31, and the wafer W is sucked and held by the negative pressure generated on the holding surface 32. Further, the chuck table 31 is configured to be rotatable around the Z axis by a rotation mechanism (not shown).

  The cutting mechanism 41 is configured to cut the outer peripheral portion of the wafer W on the chuck table 31 using a pair of blade units 42 alternately. The cutting mechanism 41 has a gate-shaped column portion 43 erected on the base 11 so as to straddle the opening 17. A ball screw type blade unit moving mechanism 44 for moving the pair of blade units 42 is provided on the surface of the column portion 43. The blade unit moving mechanism 44 has a pair of Y-axis tables 45 that move in the Y-axis direction, and a Z-axis table 46 that moves in the Z-axis direction with respect to each Y-axis table 45. The blade unit 42 is moved in the Y-axis direction and the Z-axis direction by the Y-axis table 45 and the Z-axis table 46.

  The blade unit 42 includes a disc-shaped cutting blade 48 provided at the tip of a spindle 47 and a nozzle (not shown) that injects cutting water onto the cutting portion. In the blade unit 42, the cutting blade 48 is rotated at a high speed, and the chamfered portion 91 of the wafer W is fully trimmed while spraying cutting water from a plurality of nozzles onto the cutting portion. By removing the chamfered portion 91 of the wafer W, even if the wafer W is ground from the back surface side to the finished thickness in the subsequent grinding step, the outer peripheral portion of the wafer W is shaped like a knife edge by the chamfered portion 91 remaining after grinding. It is never formed.

  In the processing area A2, the wafer W is loaded onto the chuck table 31 by the edge clamp type transfer device 51, and the wafer W is unloaded from the chuck table 31 by the edge clamp type transfer device 54. In this case, the wafer W before processing is picked up from the centering table 27 by the transfer device 51, and the wafer W is transferred to the chuck table 31 by the moving mechanism 52 (moving means). Further, the processed wafer W is picked up from the chuck table 31 by the transfer device 54, and the wafer W is transferred to the cleaning area A3 by a pivoting movement around the base end portion 55 (moving means) of the transfer device 54.

  In the cleaning area A3, a back surface cleaning mechanism 81 for cleaning the back surface of the wafer W and a surface cleaning mechanism 82 for cleaning the surface of the wafer W are provided. In the back surface cleaning mechanism 81, the back surface of the wafer W is cleaned by rubbing with a sponge or the like while spraying cleaning water from below. The wafer W after the back surface cleaning is picked up from the back surface cleaning mechanism 81 by the edge clamp type transfer device 57 and transferred to the front surface cleaning mechanism 82 by the moving mechanism 58 (moving means). In the surface cleaning mechanism 82, the spinner table 84 holding the wafer W is lowered into the base 11, cleaning water is sprayed to clean the surface of the wafer W, and then dry air is blown to dry the wafer W. The

  The wafer W after the surface cleaning is picked up from the spinner table 84 by the carry-in / carry-out arm 21 and conveyed toward the carry-out cassette C2. In the processing apparatus 1 configured as described above, between the center position detecting means 26 and the chuck table 31, between the chuck table 31 and the back surface cleaning mechanism 81, and between the back surface cleaning mechanism 81 and the front surface cleaning mechanism 82, respectively. The wafer W is transferred by the edge clamp type transfer devices 51, 54 and 57. In this case, the four claw members 63 (see FIG. 2) of the transfer devices 51, 54, and 57 are brought close to the claw member 63 to an appropriate position with respect to the outer peripheral side surface of the wafer W, and the outer peripheral portion of the wafer W is held. Is done.

  However, when transporting a wafer W whose outer diameter has changed due to full trimming processing, a wafer W in which the outer diameter varies, or the like, the claw member 63 (see FIG. 2) is appropriately applied to the outer peripheral side surface of the wafer W. Difficult to position. That is, any of the plurality of claw members 63 comes off from the outer peripheral portion of the wafer W, causing a trouble in conveyance, or one of the plurality of claw members 63 hits the side surface of the outer peripheral portion of the wafer W to damage the wafer W. There is a risk of doing. Therefore, the transfer devices 51, 54, and 57 according to the present embodiment are provided with the non-contact sensor 73 (see FIG. 2) on the claw member 63, and the claw member is positioned at an appropriate position with respect to the outer peripheral side surface of the wafer W. 63 is positioned.

  Hereinafter, with reference to FIG. 2, the detailed configuration of the transport apparatus will be described. FIG. 2 is a perspective view of the transport device according to the present embodiment. In addition, a conveying apparatus is not limited to the structure shown in FIG. The transfer device may have any configuration as long as it can detect the outer peripheral side surface of the wafer and position the plurality of claw members at appropriate positions. Here, a transfer apparatus for transferring a wafer between the center position detecting means and the chuck table will be described. The transfer device for transferring the wafer between the chuck table and the back surface cleaning mechanism and between the back surface cleaning mechanism and the front surface cleaning mechanism has the same configuration.

  As shown in FIG. 2, the transfer device 51 has an edge clamp type holding means 62 that holds the outer peripheral portion of the wafer W, and holds the outer peripheral portion of the wafer W by the four claw members 63 of the holding means 62. Is configured to do. The holding means 62 is supported on the distal end side of the transfer arm 53 (see FIG. 1) via a support portion 61, and is moved in the vertical direction (Z-axis direction) by the support portion 61, and is moved by the moving mechanism 52 (see FIG. 1). ) In the horizontal direction (Y-axis direction). As described above, in the present embodiment, the support unit 61 and the moving mechanism 52 constitute moving means for moving the holding means 62 in the vertical direction and the horizontal direction.

  The holding means 62 is provided with a long guide base 65 extending in four directions from a base portion 64 that is rectangular when viewed from above. A support wall 67 is provided on the front end side of each guide base 65 so as to face each side surface 66 of the base portion 64. Both ends of the ball screw 72 are supported by the side surface 66 and the support wall 67 of the base portion 64. Each ball screw 72 is screwed with a movable block 68 provided with a claw member 63. The claw member 63 is provided on the lower surface of the movable block 68, and is formed in a substantially L shape in a sectional view with the claw tip 69 facing the base portion 64 side. Thus, the claw member 63 is annularly arranged on the holding means 62 so as to hold the outer peripheral portion of the wafer W.

  Each ball screw 72 is connected to a plurality of claw member moving portions 71 provided for each claw member 63 on the side surface 66 of the base portion 64. Each movable block 68 is moved while being guided by the lower surface of each guide base 65 as the ball screw 72 is rotated by the claw member moving portion 71. At this time, each claw member 63 provided in each movable block 68 moves between a standby position separated from the outer peripheral portion of the wafer W and an operating position approaching in the radial direction to hold the outer peripheral portion of the wafer W. Is done. When the movable block 68 approaches, the lower surface of the wafer W is placed on the claw tip 69 of the claw member 63, whereby the outer periphery of the wafer W is held by the holding means 62.

  Each of the plurality of claw members 63 is provided with a non-contact sensor 73 having a detection surface 74 directed in the approaching direction (inner side) of the claw member 63. The non-contact sensor 73 is, for example, a capacitance sensor or a laser sensor, and detects the approach to the outer peripheral side surface of the wafer W. The detection distance from the detection surface 74 is set to, for example, 1 [mm] to 2 [mm] so that the claw member 63 does not contact the outer peripheral side surface of the wafer W. For this reason, the toe 69 of the claw member 63 protrudes from the detection surface 74 longer than the detection distance of the non-contact sensor 73 so that the lower surface of the outer peripheral portion of the wafer W can be supported.

  Further, the transport device 51 is provided with a control unit 75 (see FIG. 3) that controls the claw member moving unit 71 in accordance with a detection signal of the non-contact sensor 73. The control unit 75 includes a processor that executes various processes, a memory, and the like. The memory is composed of one or a plurality of storage media such as a ROM (Read Only Memory) and a RAM (Random Access Memory) depending on the application. When the controller 75 holds the outer periphery of the wafer W, the nail members 63 positioned in the standby position outside the wafer W are moved closer to the outer periphery of the wafer W. The member moving unit 71 is controlled. When the non-contact sensor 73 detects the outer peripheral side surface of the wafer W, the movement of each claw member moving unit 71 is stopped, and the stop position of each claw member 63 at this time is the operating position for holding the outer peripheral part of the wafer W. To.

  As described above, in the transfer device 51 according to the present embodiment, each claw member 63 is independently moved toward the outer peripheral portion of the wafer W, and the outer peripheral side surface of the wafer W is detected by the non-contact sensor 73. Stopped at the working position. For this reason, even if the wafer W has a changed outer diameter or the wafer W has a variation in outer shape, some of the claw members 63 are too close to the outer periphery of the wafer W, and some of the claw members 63 are in the outer periphery of the wafer W. The claw member 63 hits and the wafer W is not damaged. Further, since the claw tips 69 of some of the claw members 63 do not reach the outer peripheral portion of the wafer W, some of the claw members 63 are not detached from the outer peripheral portion of the wafer W.

  Hereinafter, with reference to FIG. 3, the conveyance operation by the conveyance device will be described. FIG. 3 is a diagram illustrating an example of a transport operation of the transport device according to the present embodiment. In FIG. 3, the conveyance operation between the center position detecting means and the chuck table will be described, but the conveyance operation by the conveyance device between the chuck table and the back surface cleaning mechanism and between the back surface cleaning mechanism and the front surface cleaning mechanism is the same. It is.

  As shown in FIG. 3A, the wafer W whose center position has been detected by the center position detecting means 26 is held on the centering table 27. Since the outer diameter of the centering table 27 is smaller than the outer diameter of the wafer W, the outer peripheral portion of the wafer W protrudes from the outer diameter of the centering table 27. Further, the holding means 62 is positioned above the centering table 27 so that the center position of the holding means 62 of the transfer device 51 is aligned with the center position of the wafer W detected by the center position detecting means 26. At this time, the claw members 63 positioned on the four sides of the holding means 62 are positioned at the standby positions, and the claw tips 69 of the claw members 63 are separated from the outer peripheral portion of the wafer W in the radial direction. Further, the holding means 62 is brought close to the centering table 27 and positioned so that the claw tips 69 of the claw members 63 can enter the lower side of the wafer W.

  As shown in FIG. 3B, each claw member 63 is individually moved by each claw member moving portion 71, and each claw member 63 is brought close to the outer peripheral side surface 93 of the wafer W, respectively. When the outer peripheral side surface 93 of the wafer W is detected by the non-contact sensor 73 provided on each claw member 63, a detection signal is output from the non-contact sensor 73 to the control unit 75. Based on the detection signal, the control unit 75 determines that each claw member 63 has been moved to the operating position, stops driving each claw member moving unit 71, and positions each claw member 63 at the operating position. At this operating position, the claw tip 69 of the claw member 63 enters the lower side of the outer peripheral portion of the wafer W, and the rear surface of the outer peripheral portion of the wafer W is supported from the lower side by the plurality of claw members 63.

  At this time, the length L1 of the toe 69 of each claw member 63 from the detection surface 74 of the non-contact sensor 73 is formed to be larger than the detection distance L2 from the detection surface 74. Even when the outer peripheral side surface 93 of the wafer W is separated from the detection surface 74, the outer peripheral portion of the wafer W does not come off from the toe 69. Further, the toe 69 of the claw member 63 is inclined so that the upper surface of the toe 69 becomes lower toward the tip, and the toe 69 easily enters the lower side of the outer peripheral portion of the wafer W. In this way, each claw member 63 is individually brought close to the outer peripheral side surface 93 of the wafer W, and the distance of each claw member 63 from the outer peripheral side surface 93 of the wafer W is individually controlled. Therefore, each claw member 63 can be adjusted to an appropriate position with respect to the outer peripheral side surface 93 of the wafer W irrespective of the size and variation of the outer diameter of the wafer W.

  As shown in FIG. 3C, when each claw member 63 is positioned at the operating position, the outer peripheral portion of the wafer W is hooked on the claw tip 69 of each claw member 63, and the outer peripheral portion of the wafer W is held by the holding means 62. . The wafer W is lifted from the centering table 27 while being held by the holding means 62, and is transferred toward the chuck table 31 (see FIG. 1). Since each claw member 63 is positioned at an appropriate position with respect to the outer peripheral portion side surface 93 of the wafer W, the outer peripheral portion side surface 93 of the wafer W does not abut against the detection surface 74 of the non-contact type sensor 73, and further the wafer. The toe 69 of each claw member 63 does not come off from the outer periphery of W.

  As described above, the transfer device 51 according to the present embodiment is moved independently so that the plurality of claw members 63 approach in the radial direction, and the non-contact sensor 73 of each claw member 63 moves the wafer W. When the outer peripheral side surface 93 is detected, the movement of each claw member 63 is stopped. Since each claw member 63 is stopped at a certain distance from the outer peripheral side surface 93 of the wafer W, even when the outer diameter of the wafer W varies, the plurality of claw members 63 are appropriately positioned at good working positions. It is done. Since each claw member 63 does not come off from the outer peripheral portion of the wafer W, and each claw member 63 does not abut against the outer peripheral portion side surface 93 of the wafer W, there is no need to perform an operation for adjusting the operation position. Therefore, the wafer W can be appropriately and continuously transported without generating a complicated operation.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the present embodiment, the holding means 62 is configured to hold the outer peripheral portion of the wafer W by the claw tips 69 of the four claw members 63, but is not limited to this configuration. As long as the holding means 62 can hold the outer peripheral portion of the wafer W, the number of the claw members 63 and the shape of the claw tips 69 are not particularly limited.

  In the above-described embodiment, the claw member moving unit 71 rotates the ball screw to move the claw member 63. However, the present invention is not limited to this configuration. The claw member moving part 71 may be configured by any linear motion mechanism as long as it can move the claw member 63 independently in the radial direction.

  As described above, the present invention has the effect of being able to appropriately transport wafers in which the outer diameter varies and wafers whose outer diameter has changed due to processing, and particularly after bonded wafers and trimming processing. This is useful for a wafer transfer apparatus that holds and transfers the outer periphery of the wafer.

1 Processing device 51, 54, 57 Conveying device 52, 58 Moving mechanism (moving means)
55 Base end (moving means)
61 Supporting part (moving means)
62 holding means 63 claw member 69 claw tip 71 claw member moving unit 73 non-contact sensor 74 detection surface 75 control unit 93 outer peripheral side surface W wafer

Claims (1)

A transfer device for transferring a wafer, comprising holding means for holding the outer periphery of the wafer, and moving means for moving the holding means in the vertical and horizontal directions,
The holding means is
A plurality of claw members arranged in an annular shape to hold the outer periphery of the wafer;
The plurality of claw members are independently provided between a standby position where the plurality of claw members are separated from the outer peripheral portion of the wafer and an operation position where the plurality of claw members approach each other in the radial direction and hold the outer peripheral portion of the wafer. A claw member moving part for moving in the radial direction
A non-contact type sensor that detects the outer peripheral side surface of the wafer that is arranged with the detection surface facing each other by the claw member moving unit on each of the claw members;
A control unit for controlling the claw member moving unit,
When holding the outer peripheral portion of the wafer, the control unit moves the plurality of claw members positioned at the standby position outside the outer peripheral portion of the wafer so as to approach the outer peripheral portion of the wafer. A transfer device that controls a claw member moving unit and stops the movement of each claw member moving unit when the non-contact sensor detects a side surface of the outer peripheral portion of the wafer to set the operation position.

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