Wafer transfer device

Abstract

A wafer conveyance device capable of positioning a wafer while the wafer is held by the wafer conveyance device. The wafer conveyance device has a holding plate having a holding surface facing one surface of the wafer, an attraction holding portion provided in a manner exposed on the holding surface to noncontactingly attract and hold the wafer facing the holding surface, three or more restriction members each having a roller portion capable of self-rotation, which restricts movement of the wafer relative to the holding plate in a direction parallel to the one surface of the wafer by bringing the roller portion into contact with an outer periphery of the wafer attracted and held by the attraction holding portion, and a moving unit connected to the holding plate to move the holding plate to thereby convey the wafer, at least one of the three or more restriction members being a rotation drive portion which rotates the wafer by self-rotating the roller portion in a state where the roller portion is in contact with the outer periphery of the wafer.

Description

TECHNICAL FIELD

[0001] The present application relates to a wafer conveying device that conveys wafers. BACKGROUND

[0002] A device wafer in which a plurality of devices are formed on a wafer formed mainly of silicon, gallium arsenide, silicon carbide, sapphire, or the like is subjected to processing such as grinding, polishing, cutting, or the like, and is thereby divided into a plurality of device chips. The plurality of device wafers before division are conveyed to a processing device in a state of being housed in a cassette, and are processed by the processing device.

[0003] The processing device is, for example, a taping machine. In the taping machine, the device wafers are taken out one by one from the cassette, and a protective sheet made of resin having substantially the same diameter as the device wafer is attached to the front surface side of the device wafer. The device wafers to which the protective sheets are attached are conveyed to another processing device, for example, after being housed in the cassette again.

[0004] The other processing device is, for example, a grinding device. The grinding device generally has an alignment device for positioning the device wafer with the protective sheet at a prescribed position (see, for example, Patent Literature 1). The alignment device has a temporary placement stage on which the device wafer is temporarily placed. A disc-shaped table is provided on the top of the temporary placement stage. In addition, a plurality of pins that are movable in the radial direction of the table are provided on the outer periphery of the table.

[0005] In a case where the device wafer is positioned at substantially the center of the table, the device wafer is first placed on the table. Next, while maintaining the distance from the center of the table at a mutually equal state, the plurality of pins are moved toward the center side of the table. The device wafer is positioned at substantially the center of the table by bringing each pin into contact with the outer peripheral portion of the device wafer.

[0006] Then, the device wafer is conveyed to substantially the center of a chuck table provided in the grinding device by a wafer conveying device such as a loading arm. Also, the front surface side of the device wafer is suction-held by the chuck table, and the back surface side of the device wafer is ground by a grinding unit.

[0007] In addition, as another example of the alignment device, there is a device that detects the center position of the device wafer based on an image obtained by photographing (see, for example, Patent Literature 2). The device has a temporary placement stage on which the device wafer is placed, a photographing unit that photographs the outer peripheral portion of the device wafer placed on the temporary placement stage, and a wafer conveying mechanism that conveys the device wafer from the temporary placement stage to a chuck table provided in the grinding device.

[0008] In a case where the device wafer is conveyed to substantially the center of the chuck table, first, the outer peripheral portion of the device wafer placed on the temporary placement stage is photographed by the photographing unit, and based on the obtained image, the center position of the device wafer is calculated.

[0009] Also, the temporary placement stage is rotated by a prescribed angle in such a manner that the calculated center position is located on an arc-shaped track of the wafer transfer mechanism that is rotated in an arc shape with a prescribed rotation axis as the center. Subsequently, the wafer transfer mechanism is rotated in a state in which the device wafer is adsorbed by the adsorption pad of the wafer transfer mechanism, and the device wafer is transferred to the substantially center of the chuck table.

[0010] Patent Document 1: Japanese Patent Application Publication No. H7-211766

[0011] Patent Document 2: Japanese Patent Application Publication No. 2011-210827

[0012] Thus, before the wafer is transferred to the chuck table by the wafer transfer apparatus, center alignment (i.e., centering) needs to be performed using an alignment device having a temporary placement stage and a plurality of pins or the like in addition to the wafer transfer apparatus. SUMMARY

[0013] The present application was achieved in view of this problem, and has an object to provide a wafer transfer apparatus capable of performing centering of a wafer in a state in which the wafer is held by the wafer transfer apparatus.

[0014] According to one embodiment of the present application, a wafer transfer apparatus is provided, including: a holding plate having a holding surface facing one surface of a wafer; an attraction holding portion provided in such a manner as to be exposed on the holding surface, and configured to hold the wafer facing the holding surface in an attraction manner; three or more restriction members each having a roller portion capable of self-rotation, and configured to restrict movement of the wafer with respect to the holding plate in a direction parallel to the one surface of the wafer by bringing the roller portion into contact with an outer periphery of the wafer held by the attraction holding portion; and a movement unit connected to the holding plate, and configured to move the holding plate to thereby transfer the wafer, wherein at least one of the three or more restriction members is a rotation drive portion configured to rotate the wafer by self-rotating the roller portion in a state in which the roller portion is in contact with the outer periphery of the wafer.

[0015] It is preferable that the wafer transfer apparatus further includes a notch fitting portion configured to come into contact with the outer periphery of the wafer in a state in which a force is applied toward an inner side of the wafer held by the attraction holding portion, and to be fitted with a notch provided to an outer peripheral portion of the wafer, and that the operation of the rotation drive portion is controlled in such a manner that the rotation of the rotation drive portion is stopped when the notch fitting portion is fitted with the notch.

[0016] Further, it is preferable that the wafer conveyance device further include a camera unit that photographs an outer periphery of the wafer while the wafer is attracted and held by the holding plate, and the operation of the rotation drive section is controlled in accordance with the orientation of the wafer detected by the camera unit.

[0017] Further, it is preferable that the rotation drive section include a rotation drive source coupled to a rotation shaft of the rotation drive section, and the rotation drive source rotates to cause the rotation shaft to rotate.

[0018] Further, it is preferable that the wafer conveyance device further include an external rotation drive section that causes the roller section of the rotation drive section to rotate while contacting a side surface of the roller section of the rotation drive section.

[0019] In the holding plate of the wafer conveyance device of one embodiment of the present application, an attraction and holding section that attracts and holds a wafer in a noncontact manner is provided. Further, in the wafer conveyance device, three or more restriction members each having a roller section that can rotate are provided. The roller sections are brought into contact with an outer periphery of a wafer attracted and held by the attraction and holding section, and movement of the wafer with respect to the holding plate in a direction parallel to one surface of the wafer is restricted. Thus, the wafer can be positioned at a predetermined position on the holding plate while the wafer is attracted and held by the wafer conveyance device.

[0020] Further, at least one of the restriction members is a rotation drive section that causes the roller section to rotate to cause the wafer to rotate in a state where the roller section is in contact with the outer periphery of the wafer. Thus, the wafer can be rotated to a predetermined orientation using the rotation drive section while the wafer is attracted and held by the wafer conveyance device. Thus, an alignment device provided separately from the wafer conveyance device and a center alignment process using the alignment device can be omitted. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a perspective view of a wafer conveyance device of Embodiment 1.

[0022] Figure 2 (A) of FIG. 1 is a perspective view of the upper surface side of a wafer, Figure 2 (B) of FIG. 1 is a perspective view of the lower surface side of the wafer, Figure 2 (C) of FIG. 1 is a perspective view of the lower surface side of a wafer of another example.

[0023] Figure 3 is a plan view of a hand or the like.

[0024] Figure 4 is a partial cross-sectional side view of a hand or the like.

[0025] Figure 5 is a plan view of a hand or the like of Embodiment 2.

[0026] Figure 6 (A) is a top view of the hand and the like according to the third embodiment. Figure 6 (B) is a perspective view of the external rotation drive unit.

[0027] Description of labels

[0028] 11: Wafer; 11a: Front; 11b: Back (one side); 11c: Peripheral edge; 13: Predetermined dividing line; 15: Device; 17: Notch; 19a: Recess; 19b: Peripheral ring; 10: Wafer transport device; 12: Moving unit; 14: First supporting rotating part; 16: First connecting rod; 18: Second connecting rod; 20: Cylindrical shell; 22: Third connecting rod; 24: Arm rotating shaft; 26: Arm; 28: Hand; 30: Holding plate; 30a: Wrist; 30b: Connecting part; 30c: Finger; 30d: Holding Surface; 32: Pad (attraction and holding portion); 34: Roller clamp (limiting component); 34a: Supporting rotation portion; 34b: Roller portion; 34c: First rotation drive source; 36: Moving plate; 36a: First area; 36b: Second area; 38: Camera unit; 40: Notch fitting portion; 40a: One end; 40b: The other end; 42: External rotation drive portion; 42a: Second rotation drive source; 42b: Housing; 42c: Rotation axis; 42d: Roller portion; A: First direction; B: Second direction; C: Third direction (height direction). DETAILED DESCRIPTION

[0029] An embodiment of one aspect of the present invention will be described with reference to the drawings. Figure 1 1 is a perspective view of the wafer transfer apparatus 10 according to the first embodiment. In the following description, the first direction A, the second direction B, and the third direction C are perpendicular to each other. The third direction C is the height direction of the wafer transfer apparatus 10 .

[0030] The wafer transfer device 10 is provided in, for example, a cutting device, a grinding device, a polishing device, a grinding / polishing device, a laser processing device (not shown), etc. In addition, the wafer transfer device 10 may also be provided in a tape attaching machine (not shown) that attaches a resin protective sheet or the like to the wafer.

[0031] The wafer transfer device 10 is a so-called multi-jointed robot. The wafer transfer device 10 includes a moving unit 12 having a multi-jointed link structure with an open loop structure. The moving unit 12 includes a first supporting rotating portion 14 having a cylindrical shape.

[0032] The first supporting and rotating part 14 has a cylindrical housing. A moving mechanism (not shown) capable of vertical movement in the third direction C (height direction) is connected to the bottom of the housing. The first supporting and rotating part 14 can move in the third direction C by the moving mechanism.

[0033] A first rotation shaft (not shown) that is substantially parallel to the third direction C is housed inside the housing of the first support rotation section 14. A first drive source (not shown) such as a motor is connected to the bottom of the first rotation shaft, and the bottom side of the first link 16 on the one end side of the first link 16 is connected to the upper side of the first rotation shaft.

[0034] The first drive source is activated, and the first link 16 rotates in a plane parallel to the plane defined by the first direction A and the second direction B (hereinafter referred to as the AB plane) with the first rotation shaft on the one end side of the first link 16 as a fulcrum.

[0035] A first pulley (not shown) is provided on the one end side of the first link 16. In addition, a second pulley (not shown) is provided on the other end side of the first link 16 and is connected to the first pulley via a transmission belt (not shown). The first pulley, the transmission belt, and the second pulley are housed inside the housing of the first link 16.

[0036] A second rotation shaft (not shown) that is substantially parallel to the third direction C is connected to the second pulley. The upper side of the second link 18 on the one end side of the second link 18 is connected to the upper side of the second rotation shaft. Therefore, when the first pulley is rotated, the second pulley and the second link 18 are rotated via the transmission belt, and the second link 18 rotates in a plane parallel to the AB plane.

[0037] A third rotation shaft (not shown) that is substantially parallel to the third direction C is connected to the upper side of the second link 18 on the other end side of the second link 18. The third rotation shaft is housed inside the cylindrical housing 20. A second drive source (not shown) such as a motor is connected to the bottom of the third rotation shaft.

[0038] In addition, the bottom side of the third link 22 is connected to the upper side of the third rotation shaft. The second drive source is activated, and the third link 22 rotates in a plane parallel to the AB plane with the third rotation shaft as a fulcrum. An arm rotation shaft 24 that is a straight line parallel to the AB plane is provided on the side of the third link 22.

[0039] A third drive source (not shown) such as a motor provided in the housing of the third link 22 is connected to the one end side of the arm rotation shaft 24. The third drive source is activated, and the arm rotation shaft 24 rotates with the straight line parallel to the AB plane as an axis of rotation.

[0040] The one end side of a rectangular parallelepiped-shaped arm 26 is fixed to the other end side of the arm rotation shaft 24. A hand 28 that is an end effector is connected to the other end side of the arm 26. The hand 28 has a holding plate 30 formed of metal, ceramic, or the like.

[0041] The holding plate 30 has a rectangular-shaped wrist portion 30a on one end side of the hand portion 28 (i.e., the arm 26 side). In addition, a connecting portion 30b having a width wider than the wrist portion 30a is provided on the side opposite the wrist portion 30a with respect to the arm 26.

[0042] Two finger portions 30c are provided on the side opposite the wrist portion 30a with respect to the connecting portion 30b in a manner symmetrical with respect to the center in the width direction of the connecting portion 30b. Each finger portion 30c extends in a direction substantially parallel to the axis direction of the arm rotation shaft 24 (i.e., the length direction of the holding plate 30). In addition, the two finger portions 30c are separated from each other in the width direction of the holding plate 30 perpendicular to the length direction of the holding plate 30.

[0043] A plurality of pads 32 are provided on the front side of the holding plate 30 (i.e., the holding surface 30d) in a manner exposed from the holding surface 30d. Each pad 32 constitutes a suction holding portion for suction holding the wafer 11 (described in detail later).

[0044] Two pads 32 are provided on the connecting portion 30b in a manner separated from each other in the width direction of the holding plate 30. In addition, two pads 32 are provided on each finger portion 30c in a manner separated from each other in the length direction of the holding plate 30. However, the number and arrangement of the pads 32 are not limited to the above-described example.

[0045] Each pad 32 is substantially disc-shaped, and a ring-shaped recessed portion is provided on the exposed surface side of each pad 32. A plurality of nozzles (not shown) for ejecting a fluid such as air are provided on the side of the inner periphery of the ring-shaped recessed portion in a dispersed manner along the circumferential direction of the recessed portion. For example, four nozzles are provided in a manner equally spaced apart along the circumferential direction of the recessed portion.

[0046] Air is supplied to each nozzle from an air supply source (not shown). When one surface (e.g., the back surface lib) of the wafer 11 is positioned in a manner facing each pad 32 in a state in which air is being ejected from the exposed surface side of each pad 32 (refer to (A) to (C) of FIG. 6), the air flows in the gap between the one surface of the wafer 11 and the pad 32. Figure 2 Figure 2

[0047] When the flow rate of the air flowing in the gap increases, the pressure of the gap decreases in accordance with Bernoulli's theorem. As a result, a negative pressure is generated on the exposed surface side of the pad 32, which is lower than the atmospheric pressure by a prescribed pressure. By this negative pressure, the wafer 11 is not in contact with the holding surface 30d and the pad 32, but is suction held by the holding surface 30d in a non-contact manner.

[0048] ​​The air ejected from the exposed surface side of the pad 32 is ejected, for example, in a cyclone shape, but can also be ejected in a radial shape. In addition, the orientation, flow rate, and the like of the ejection of the air are appropriately adjusted in such a manner that the wafer 11 does not rotate in a plane parallel to one face of the wafer 11 due to the ejected air.

[0049] Here, the wafer 11 held by the holding plate 30 is described using Figure 2 (A) to Figure 2 (C). Figure 2 (A) is a perspective view of the upper surface side of the wafer 11, Figure 2 (B) is a perspective view of the lower surface side of the wafer 11.

[0050] The wafer 11 has, for example, a circular disk-shaped substrate with a diameter of 300 mm. The front face 11a side of the wafer 11 is divided into a plurality of regions by a plurality of division intended lines (spacer lines) 13 that intersect each other, and a device 15 such as an IC (Integrated Circuit) is formed in each region.

[0051] The substrate of the present embodiment is formed using a semiconductor material such as silicon (Si), but the material, shape, configuration, size, and the like of the substrate are not limited. The substrate can be formed of other semiconductors, ceramics, resins, and the like. In addition, the kind, number, shape, configuration, size, arrangement, and the like of the device 15 are also not limited. The device 15 can also not be formed on the front face 11a side.

[0052] A slanting portion is formed between the front face 11a and the outer peripheral edge 11c and between the back face 11b and the outer peripheral edge 11c. In addition, a notch 17 that indicates the crystal orientation of the substrate of the wafer 11 is formed in the outer peripheral portion of the wafer 11.

[0053] In addition, the wafer 11 is not limited to the examples shown in Figure 2 (A) and Figure 2 (B). The wafer 11 can also be a so-called wafer with projections in which a plurality of projections (not shown) made of metal are provided on the front face 11a side.

[0054] Figure 2 (C) is a perspective view of the lower surface side of the wafer 11 of another example. As shown in Figure 1 (C), a circular recess 19a can be formed on the wafer 11 by grinding and removing the inner peripheral portion of the back face 11b side. The outer peripheral ring 19b remains in the outer peripheral portion of the wafer 11, and thus the warping of the wafer 11 can be reduced and the strength of the wafer 11 can be further improved compared to the case where the recess 19a is not formed.

[0055] Next, reference is made to Figure 3 , Figure 4 , and Figure 3The roller jig 34 as another component of the wafer conveyance device 10 will be described. Figure 4 is a plan view of the hand 28 and the like. Figure 1 is a partially cutaway side view of the hand 28 and the like.

[0056] Three or more roller jigs (restricting members) 34 that restrict movement of the wafer 11 in a direction parallel to one face (for example, the back face lib) of the wafer 11 held by the plurality of pads 32 are provided on the hand 28.

[0057] In addition, movement of the wafer 11 in a direction parallel to one face of the wafer 11 refers to movement in a straight line direction such as the first direction A and the second direction B, and does not refer to rotation of the wafer 11 about a prescribed axis.

[0058] One roller jig 34 is provided at the tip end of each finger portion 30c. In addition, a pair of roller jigs 34 is provided laterally of the wrist portion 30a. That is, a total of four roller jigs 34 are provided in the wafer conveyance device 10.

[0059] The pair of roller jigs 34 provided laterally of the wrist portion 30a is linked to a moving plate 36 located below the wrist portion 30a. In addition, the moving plate 36 is omitted in Figure 3

[0060] The moving plate 36 is capable of advancing and retreating in the length direction of the holding plate 30 by means of an actuator not shown. The moving plate 36 has a first region 36a linked to the other end side of the arm 26. A rod-shaped second region 36b having a length greater than the width of the wrist portion 30a is provided on the side opposite the first region 36a from the arm 26.

[0061] The second region 36b has a shape symmetrical about a prescribed center line, and is arranged in a manner symmetrical about the center in the width direction of the wrist portion 30a. The pair of roller jigs 34 described above are provided at both ends of the second region 36b.

[0062] Here, the configuration of the roller jig 34 will be described. The roller jig 34 has a cylindrical support rotation portion 34a fixed to the tip end of the finger portion 30c and both end portions of the second region 36b, respectively. A rotation axis (not shown) in the third direction C is provided in the support rotation portion 34a.

[0063] A disc-shaped roller portion 34b having a diameter greater than the diameter of the support rotation portion 34a is provided at the upper portion of the rotation axis. The roller portion 34b is formed of, for example, a resin foam body having a degree of hardness that does not damage the wafer 11. The roller portion 34b has a coefficient of friction that does not slip even when in contact with the outer periphery lie of the wafer 11.

[0064] ​The roller portion 34b of each roller jig 34 can rotate while in contact with the outer peripheral edge 11c. A first rotational drive source 34c such as a motor or actuator is connected to the bottom of the rotation shaft (not shown) of at least one of the roller jigs 34.

[0065] The roller clamp 34 connected to the first rotation drive source 34c functions as a rotation drive unit that rotates (rotates) the wafer 11. Figure 4 and Figure 3 In the illustrated example, one roller clamp 34 located at the tip of the finger 30 c and on one side in the second direction B includes a first rotational drive source 34 c and functions as a rotational drive unit.

[0066] In this embodiment, the first rotation drive source 34c is operated while the rollers 34b are clamped at four different locations on the outer peripheral edge 11c, thereby rotating the rotation axis of the rotation drive unit and the rollers 34b. This allows the wafer 11 to be rotated (rotated) while limiting movement of the wafer 11 in a direction parallel to one surface of the wafer 11.

[0067] For example, Figure 5 In the plan view shown, if the roller portion 34 b is rotated clockwise, the wafer 11 can be rotated counterclockwise. Similarly, if the roller portion 34 b is rotated counterclockwise, the wafer 11 can be rotated clockwise.

[0068] The roller clamp 34 functioning as the rotational drive unit is not limited to the roller clamp 34 located at the tip of the finger 30 c and on one side in the second direction B, but may be located at any position. Furthermore, the number of roller clamps 34 functioning as the rotational drive unit is not limited to one, but may be two or more.

[0069] A camera unit 38, a component of the wafer transfer device 10, is installed near the wafer transfer device 10 so as to face the holding surface 30d. The camera unit 38 includes a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. The camera unit 38 captures the outer edge 11c of the wafer 11 held on the holding surface 30d from above and transmits the captured image to a control unit described later.

[0070] The camera unit 38 of the present embodiment is separated from the holding plate 30 and fixed to a prescribed position. However, if the camera unit 38 is a small camera unit 38 to the extent that it does not obstruct entry into a cassette in which the wafer 11 is housed, it can be fixed to the holding plate 30 in a manner of being positioned laterally of the holding plate 30. The camera unit 38 fixed to the holding plate 30 can, for example, shoot the outer peripheral portion of the wafer 11 from above, or can shoot the outer peripheral portion of the wafer 11 from below.

[0071] The wafer conveyance device 10 is part of a processing device (not shown), and the operation of the wafer conveyance device 10, the camera unit 38, and the like is controlled by a control section (not shown) that controls the operation of the processing device. The control section is constituted by a computer including a processing device such as a CPU (Central Processing Unit), a storage device such as a flash memory, and the like.

[0072] The processing device is caused to operate in accordance with software such as a program stored in the storage device, and the control section functions as a concrete unit that causes the software to cooperate with the processing device (hardware resources).

[0073] The control section includes an image processing section (not shown) that processes the image shot by the camera unit 38, thereby detecting the notch 17 of the wafer 11 and the like. The image processing section is realized by, for example, software stored in the storage device, but is not limited to software and can be hardware such as an ASIC (Application Specific Integrated Circuit) for a specific purpose.

[0074] Next, a method of conveying the wafer 11 using the wafer conveyance device 10 shown in the first embodiment will be described. In addition, a cassette (not shown) that houses a plurality of wafers 11 is placed on a cassette placement table (not shown) of a processing device.

[0075] First, the moving unit 12 is caused to operate so that the hand 28 is inserted into the cassette (insertion step S10). Also, fluid is ejected from the plurality of pads 32, thereby attracting and holding, for example, the back surface 11b side of the wafer 11 (attractive holding step S20).

[0076] Next, the moving plate 36 is caused to move from the arm 26 side to the connection portion 30b side until the outer peripheral edge 11c of the wafer 11 comes into contact with the roller portion 34b of each of the roller clamps 34 (contact step S30). Thereby, the movement of the wafer 11 in a direction parallel to the back surface 11b of the wafer 11 is restricted by the four roller clamps 34.

[0077] After the wafer 11 is aligned by the contact step (S30), the moving unit 12 is operated to extend the hand 28 outside the cassette, and the outer peripheral portion of the wafer 11 is positioned below the camera unit 38. Then, while rotating the wafer 11 by the rotation drive portion, the outer peripheral portion of the wafer 11 is imaged by the camera unit 38 (imaging step (S40)).

[0078] At this time, the image processing portion detects the notch 17 in the image. If the notch 17 is detected in the image, the rotation of the wafer 11 is stopped. Next, the control portion calculates how much the orientation of the wafer 11 (i.e., the position of the notch 17) is deviated from the predetermined orientation (i.e., how much the angle is).

[0079] The control portion operates the first rotation drive source 34c to rotate the wafer 11 by the angle required according to the orientation of the notch 17 (wafer rotation step (S50)). In addition, the wafer 11 is restricted from moving in the direction parallel to the back surface lib of the wafer 11 by the four roller clamps 34, but is not restricted from moving in the circumferential direction of the wafer 11.

[0080] By causing the roller portion 34b of the rotation drive portion to rotate, the wafer 11 can be rotated (self-rotation) around the prescribed axis, and thus the notch 17 can be positioned at the prescribed position with respect to the hand 28. That is, the orientation of the wafer 11 can be adjusted.

[0081] Thus, in the present embodiment, the positioning and the adjustment of the orientation of the wafer 11 can be performed while the wafer 11 is held by the hand 28. Therefore, the alignment device provided separately from the wafer transfer device 10 and the center alignment process using the alignment device can be omitted.

[0082] After the wafer rotation step (S50), the moving unit 12 is operated to transfer the wafer 11 held by suction by the hand 28 to a chuck table (not shown) provided in a processing region (transfer step (S60)).

[0083] At this time, the third drive source is operated to rotate the arm rotation shaft 24 by 180 degrees, and thus the wafer 11 is flipped. In addition, the wafer 11 is held by suction by the holding surface 30d, and thus the wafer 11 does not fall from the holding surface 30d even if the holding surface 30d is flipped.

[0084] For example, the wafer 11 is placed on the chuck table in such a manner that the back surface lib side of the wafer 11 is exposed and the front surface 11a side faces the chuck table surface. In addition, in the present embodiment, an example in which the back surface lib side of the wafer 11 is held by the holding surface 30d is described, but the front surface 11a side of the wafer 11 can be held by suction by the holding surface 30d.

[0085] Next, the second embodiment of the wafer transfer device 10 will be described. Figure 6 is a plan view of the hand 28 and the like of the second embodiment. The hand 28 of the second embodiment has the notch fitting portion 40 instead of the camera unit 38.

[0086] The notch fitting portion 40 is a rod-shaped member having a planar substantially L-shaped shape. One end 40a of the notch fitting portion 40 is connected to one end side of the second region 36b of the moving plate 36 in a rotatable manner. In addition, a biasing member (not shown) such as a spring is connected to the one end 40a side of the notch fitting portion 40, and biases the notch fitting portion 40 in a planar clockwise direction.

[0087] The other end 40b side of the notch fitting portion 40 has a convex shape that can be fitted into the notch 17. The notch fitting portion 40 is arranged so that the other end 40b is not directed toward the arm 26 side but is directed toward the connecting portion 30b and the finger portion 30c side.

[0088] Next, the method of transferring the wafer 11 according to the second embodiment will be described. In the second embodiment, the insertion step (S10) and the suction and holding step (S20) are also performed. In the contact step (S30), the moving plate 36 is moved while the wafer 11 is being held by suction using the holding surface 30d, so that each of the roller clamps 34 comes into contact with the outer peripheral edge 11c. At this time, the other end 40b of the notch fitting portion 40 also comes into contact with the outer peripheral edge 11c by the force directed toward the inner side of the wafer 11.

[0089] In the second embodiment, the photographing step (S40) is omitted, and the wafer rotation step (S50) is performed. In the wafer rotation step (S50) of the second embodiment, the operation of the roller clamp 34 is controlled by the control portion so that the rotation of the roller clamp 34 is stopped when the other end 40b of the notch fitting portion 40 is fitted into the notch 17. In this way, the wafer 11 is rotated so that the notch 17 is positioned at a prescribed position with respect to the hand 28. Then, the transfer step (S60) is performed as in the first embodiment.

[0090] In the second embodiment, the positioning and the adjustment of the orientation of the wafer 11 can also be performed while the wafer 11 is being held by the hand 28. Therefore, the alignment device and the center alignment process using the alignment device, which are provided separately from the wafer transfer device 10, can be omitted.

[0091] Next, the third embodiment of the wafer transfer device 10 will be described. Figure 6 (A) of FIG. 10 is a plan view of the hand 28 and the like of the third embodiment. In the third embodiment, the first rotation drive source 34c is not provided in the roller clamp 34 that functions as the rotation drive portion.

[0092] Instead, the external rotary drive section 42, which is a component of the wafer conveyance device 10, is separated from the holding plate 30 and fixed to a prescribed position. ​ FIG. 42 is a perspective view of the (B) external rotary drive section 42. The external rotary drive section 42 has a motor, an actuator, or the like as a second rotary drive source 42a.

[0093] The second rotary drive source 42a is housed in a substantially rectangular housing 42b. A rotary shaft 42c is connected to the second rotary drive source 42a. On the rotary shaft 42c, a disc-shaped roller section 42d having a larger diameter than the diameter of the rotary shaft 42c is fixed to the end portion on the side opposite the second rotary drive source 42a.

[0094] The roller section 42d is formed of a resin foam, for example, like the roller section 34b, but the material of the roller section 42d is not particularly limited if it has a coefficient of friction to the extent that it does not slip even when it comes into contact with the roller section 34b.

[0095] The roller section 42d of the external rotary drive section 42 causes the roller section 34b to rotate in a state in which it is in contact with the side surface of the roller section 34b of the roller jig 34 that functions as a rotary drive section, and thereby can cause the wafer 11 that is in contact with the side surface of the roller section 34b to rotate.

[0096] In the method of conveying the wafer 11 of the third embodiment, the drive source that causes the wafer 11 to rotate in the wafer rotation step (S50) is not the first rotary drive source 34c, but the second rotary drive source 42a, which is different from the first embodiment. The other aspects are the same as the first embodiment. In the third embodiment, the first rotary drive source 34c is not provided on the hand 28, and thus the configuration of the hand 28 can be simplified compared to the first embodiment.

[0097] In addition, in the third embodiment, the positioning and the adjustment of the orientation of the wafer 11 can also be performed in a state in which the wafer 11 is held by the hand 28. Thus, a collet device that is provided separately from the wafer conveyance device 10 and a center alignment process using the collet device can be omitted.

[0098] In addition, the external rotary drive section 42 of the present embodiment is separated from the holding plate 30, but as long as it is a small external rotary drive section 42 that does not interfere with the entry of the cassette, the external rotary drive section 42 can be fixed to the holding plate 30 in a manner in which it is positioned to the side of the holding plate 30.

[0099] In addition to the above, the configuration, method, and the like of the above-described embodiments can be appropriately changed and implemented as long as the purpose of the present application is not deviated from. If one example is given, the configuration of the plurality of pads 32, the flow rate of air supplied to the plurality of pads 32, the supply path of air, and the like can be changed in a manner in which the directions of air ejected from the pads 32 are different directions.

[0100] More specifically, in a case where the holding surface 30d of the hand 28 is observed in plan view, air in a cyclone shape rotating clockwise is ejected from at least one pad 32 provided to one of the finger portions 30c. In addition, air in a cyclone shape rotating counterclockwise is ejected from at least one pad 32 provided to the other of the finger portions 30c.

[0101] In this case, by adjusting the flow rate of air, the self-rotation of the wafer 11 based on the rotation drive portion can be assisted using the air ejected from the pads 32. For example, the flow rate of air rotating clockwise is made larger than the flow rate of air rotating counterclockwise. Thereby, the wafer 11 can be suction-held in a non-contact manner while the clockwise self-rotation of the wafer 11 is assisted by air rotating clockwise in a relatively large flow rate.

[0102] Likewise, if the flow rate of air rotating counterclockwise is made larger than the flow rate of air rotating clockwise, the wafer 11 can be suction-held in a non-contact manner while the counterclockwise self-rotation of the wafer 11 is assisted by air rotating counterclockwise in a relatively large flow rate.

Claims

1. A wafer transport device, characterized in that: The wafer transport device has: a holding plate having a holding surface facing one surface of the wafer; a suction and holding portion, which is disposed in a manner exposed on the holding surface and suctions and holds the wafer facing the holding surface in a non-contact manner; three or more limiting members, each having a rotatable roller portion, which limits movement of the wafer relative to the holding plate in a direction parallel to the one surface of the wafer by bringing the roller portion into contact with an outer peripheral edge of the wafer held by the suction and holding portion; as well as A moving unit connected to the holding plate moves the holding plate to transport the wafer. At least one of the three or more limiting members is a rotation drive unit that rotates the wafer by rotating the roller while the roller is in contact with the outer periphery of the wafer. The wafer transfer device further includes an external rotation drive unit that rotates the roller portion of the rotation drive unit while in contact with a side surface of the roller portion of the rotation drive unit.

2. The wafer transfer device according to claim 1, wherein: The wafer transfer device further includes a notch fitting portion that contacts the outer peripheral edge of the wafer while applying force toward the inner side of the wafer held by the holding plate and can fit into a notch provided on the outer peripheral portion of the wafer. The operation of the rotation drive unit is controlled so that the rotation of the rotation drive unit stops when the notch fitting portion is fitted into the notch.

3. The wafer transfer device according to claim 1, wherein: The wafer transfer device further includes a camera unit for photographing the outer periphery of the wafer while the wafer is being held by suction on the holding plate. The operation of the rotation drive unit is controlled based on the orientation of the wafer detected by the camera unit.

4. The wafer transfer device according to claim 1, wherein: The external rotation driving portion is separated from the holding plate and fixed at a predetermined position.

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