JP6581436B2 - Robot hand - Google Patents

Description

  The present invention relates to a robot hand that sucks and holds a wafer in a processing apparatus and carries it in and out.

  Wafers used in semiconductor manufacturing include wafers where one side of the wafer is not flat. For example, in a wafer in which a resin is molded on one side of a wafer, the central region on the resin surface side of the wafer is concave and curved in a concave shape due to shrinkage of the molded resin.

  In the case of grinding the resin surface of such a bowl-shaped wafer, first, in the apparatus for molding the resin, the wafer in which the resin is molded is stored in the cassette. And the cassette in which this wafer was accommodated is mounted in the cassette stage with which a grinding apparatus is equipped. Thereafter, the robot hand unloads the wafer from the cassette, conveys it onto the chuck table, and is ground. Such a process is the same as in the case of a wafer in which both sides are flat.

  However, it is difficult to carry out the wafer curved in a bowl shape from the cassette in the grinding apparatus. This is because it becomes difficult for the robot hand to enter the cassette because the gap between the wafers accommodated in the cassette becomes narrow due to the curvature of the wafer. Further, due to the curvature of the wafer, a suction error such as a vacuum leak is likely to occur when the robot hand sucks and holds the wafer.

  In order to prevent the suction error of such a curved wafer, there is a robot hand provided with a suction cup at the suction port (see, for example, Patent Document 1).

JP 2009-285823 A

  However, since the gap between the wafers in the cassette is narrow, there is a problem that it becomes more difficult for the robot hand to enter the cassette by providing a suction cup at the suction port. In addition, if the wafer is sucked and held by the suction cup, the suction cup can follow the inclined surface of the curved wafer and the suction hold can be performed more reliably. However, when the suction holding is performed, the center of gravity of the wafer is recognized. Need to be. That is, for example, when there are two suction cups provided in the suction port, it is necessary to position and hold the suction cup with the center of gravity of the wafer sandwiched between the wafer and the wafer in order to prevent deformation of the wafer. Therefore, it is necessary to allow the robot hand to enter the center of the cassette. However, since the gap between the wafers in the cassette is narrow, there may be a case where the robot hand cannot sufficiently enter due to the suction cup.

  Therefore, in the case where the wafer in the cassette is sucked and held by the robot hand, there is a problem that the wafer can be surely and easily carried in and out of the cassette even if the wafer is curved in a bay shape.

The present invention for solving the above problems is a robot hand for carrying out a wafer curved in a bowl shape from a cassette , or carrying a wafer curved in a bowl shape into a cassette, wherein the outer peripheral portion of the front surface or the back surface of the wafer is formed. Two suction cups for sucking and holding, a plate in which the two suction cups are spaced apart from each other, and a suction path that is disposed on the plate and communicates the suction cups with a suction source . An elliptical through hole that is formed in an elliptical shape and communicates with the suction path, on a vertical line that passes through the midpoint of a line segment that connects the centers of the two suction cups, and for each minor axis of the two suction cups the intersection of the extension line position the center of the wafer is placed along the respective long axes of the two suction cups on the outer periphery of the wafer is a robot hand for sucking and holding the outer peripheral portion of the wafer.

  It is preferable that the two suction cups have an elliptical shape, and the intersection of the extended lines of the short axes of the two suction cups is the center of the wafer.

A robot hand according to the present invention is a robot hand for carrying out a wafer curved in a bowl shape from a cassette, or carrying it into a cassette, wherein two suction cups for sucking and holding the outer peripheral portion of the front surface or the back surface of the wafer, The suction cup includes a plate having a suction cup spaced apart and a suction path that is provided on the plate and communicates the suction cup with a suction source. The two suction cups are formed in an elliptical shape, and have an elliptical shape that communicates with the suction path. Each of the two suction cups has a hole on the perpendicular line passing through the midpoint of the line segment connecting the centers of the two suction cups and at the intersection of the extension lines of the short axes of the two suction cups . by sucking and holding the outer peripheral portion of the wafer is placed along the major axis to the outer periphery of the wafer, it is not necessary to enter the robot hand deep into the cassette interior is eliminated, which facilitates entry into the robot hand cassette . Moreover, it can prevent that a vacuum leak generate | occur | produces by making a suction cup contact along the curvature of the surface of a wafer, and performing adsorption | suction. Further, since the object to be carried in and out is a curved wafer, even if the outer peripheral portion of the wafer is sucked and held by suction, deformation due to the drooping of the wafer does not occur.

  In addition, the two suction cups are elliptical and are arranged on the plate so that the intersection of the short axes of the two suction cups is at the center of the wafer, so that the wafer can be sucked and held by the robot hand. When performing, since the contact area between the two suction cups and the wafer is maximized, the occurrence of vacuum leak can be further prevented.

It is a perspective view of the cassette in which the robot hand and the wafer were accommodated. It is a top view which shows the state which sucked and hold | maintained the wafer from the surface side (-Z direction side) of the wafer, and was carried out from the cassette. It is a side view which shows the state which sucked and hold | maintained the wafer from the surface side (-Z direction side) of a wafer, and was carried out from the cassette. It is a top view which shows the state which sucked and hold | maintained the wafer from the back surface side (+ Z direction side) of the wafer, and was carried out from the cassette. It is a side view which shows the state which sucked and hold | maintained the wafer from the back surface side (+ Z direction side) of a wafer, and is carrying out from a cassette. It is a perspective view which shows an example of embodiment of the suction cup with which a robot hand is equipped.

  A robot hand 1 shown in FIG. 1 is a robot hand for carrying out a wafer W curved in a bowl shape accommodated in a cassette 4 from the cassette 4 and carrying it in the cassette 4, for example, a grinding device (not shown) It is arranged on the top.

  The robot hand 1 includes two suction cups 10a and 10b that suck and hold the outer peripheral portion Wc of the wafer W, a plate 11 in which the two suction cups 10a and 10b are spaced apart from each other, a suction cup 10a that is provided in the plate 11, and And at least a suction passage 13 for communicating 10b with the suction source 12.

  The plate 11 is formed in a U-shaped flat plate shape in which a first support portion 111 and a second support portion 112 protrude from the base portion 110 in the same direction, and the first support portion 111 and the second support portion 112 are formed. It enters the inside of the cassette 4 from the front end side.

  On the surface 11 a of the plate 11, a first suction port 111 a is opened on the top surface of the first support portion 111, and a second suction port 112 a is opened on the top surface of the second support portion 112. ing. The first suction port 111a is provided with a first suction cup 10a, and the second suction port 112a is provided with a second suction cup 10b.

  The first suction cup 10a (second suction cup 10b) shown in FIG. 1 is, for example, an elastic material such as rubber formed in an elliptical shape, for example, and has a first suction port 111a (second An elliptical through hole 100 (105) communicating with the suction port 112a) is provided.

  For example, the first suction cup 10a is configured so that the center of the through hole 100 (105) and the center of the first suction port 111a (second suction port 112a) coincide with each other. 2 on the top end of the support part 112).

  As shown in FIG. 1, the first suction port 111 a (second suction port 112 a) communicates with the suction path 13. For example, the suction path 13 is disposed in the plate 11 so as to pass through the inside of the plate 11, and one end thereof is connected to a suction source 12 including a vacuum generator and a compressor. The suction force generated by suction by the suction source 12 is transmitted through the suction path 13 to the contact surface with the wafer W of the first suction cup 10a (second suction cup 10b).

  A holder 20 that holds the plate 11 is connected to the base 110 of the plate 11, and one end of a spindle 21 is connected to the holder 20. The axial direction of the spindle 21 is the same as the direction in which the plate 11 enters the cassette 4 (the protruding direction of the first support portion 111). The spindle 21 is rotatably supported by a spindle housing 22, and a motor (not shown) is connected to the other end of the spindle 21. As the motor (not shown) rotates the spindle 21, the plate 11 connected to the spindle 21 rotates, so that the front surface 11a of the plate 11 and the back surface 11b of the plate 11 can be reversed up and down. The spindle 21 may be configured to be movable from the spindle housing 22 in the horizontal direction, for example.

  The spindle housing 22 is connected to a drive unit 3 that moves the plate 11 to a predetermined position. The drive unit 3 includes, for example, a first arm 30, a second arm 31, a plate turning means 32, a first arm turning means 33, and a second arm turning means 34, The operation is controlled by a control unit 6 including at least a CPU and a storage element such as a memory.

  The upper surface of one end of the first arm 30 is connected to the plate turning means 32 connected to the lower surface of the spindle housing 22. The upper surface of one end of the second arm 31 is connected to the lower surface of the other end of the first arm 30 via the first arm turning means 33. A second arm turning means 34 is connected to the lower surface of the other end of the second arm 31. The second arm turning means 34 is disposed on the Z-axis direction moving means 5.

  The plate turning means 32 turns the plate 11 horizontally with respect to the first arm 30 by a rotational force generated by a turning drive source (not shown). The first arm turning means 33 turns the first arm 30 horizontally with respect to the second arm 31 by a rotational force generated by a turning drive source (not shown). The second arm turning means 34 turns the second arm 31 horizontally with respect to the Z-axis direction moving means 5 by a rotational force generated by a turning drive source (not shown). The operation of the Z-axis direction moving means 5 is controlled by the control unit 6 and moves the robot hand 1 in the Z-axis direction with respect to a grinding device (not shown), that is, moves up and down. The positions of the wafer W and the plate 11 accommodated in the Z axis direction are matched.

  The position of the midpoint M1 of the line segment L1 connecting the center of the first suction cup 10a and the center of the second suction cup 10b shown in FIG. 2 is stored in the control unit 6 provided in the robot hand 1. For example, the control unit 6 operates the driving unit 3 to superimpose the diameter of the wafer W and the vertical line L2 passing through the midpoint M1 of the line segment L1, thereby causing the control unit 6 on the vertical line L2 passing through the midpoint M1 of the line segment L1 Position the center Wo of the wafer W.

  Further, as shown in FIG. 2, the intersection of the short axis extension line 102a passing through the center of the first suction cup 10a and the short axis extension line 102b passing through the center of the second suction cup 10b coincides with the center Wo of the wafer W. When the first suction cup 10a and the second suction cup 10b are arranged as described above, the major axes of the first suction cup 10a and the second suction cup 10b are aligned with the outer periphery Wd of the wafer W.

  The cassette 4 shown in FIG. 1 has a bottom plate 4a, a top plate 4b, a rear wall 4c, two side walls 4d, and an opening 4e on the front side (+ Y direction side). It becomes the structure which can carry in / out W. A plurality of shelves 40 are formed in the cassette 4 at predetermined intervals in the vertical direction, and the wafers W can be stored one by one in the horizontal state in the shelves 40. . For example, each shelf 40 is formed of a flat plate whose central region is cut out in a substantially rectangular shape, and the wafer W can be accommodated in the cassette 4 while supporting the outer peripheral portion Wc of the wafer W. Note that the cassette 4 may be configured to be capable of reciprocating in the Z-axis direction while being placed on a cassette stage (not shown), for example.

  The wafer W having a circular outer shape shown in FIG. 1 has, for example, a surface that is sealed with resin, and gradually warps from the center of the wafer W toward the outer peripheral portion Wc. Is curved. That is, the surface Wa on the resin surface side is curved in a concave shape. For example, the wafer W is accommodated in the cassette 4 with the back surface Wb facing upward.

  The operation of the robot hand 1 when the wafer W is carried out from the cassette 4 by the robot hand 1 will be described below with reference to FIGS. Here, the wafer Wa is sucked and held by adsorbing the surface Wa of the wafer W, that is, the plate 11 is raised and approached from the lower side (−Z direction side) with respect to the wafer W.

  First, the Z-axis direction moving mechanism 5 shown in FIG. 1 moves the plate 11 in the Z-axis direction so that the plate 11 and the wafer W in the wafer cassette 4 are aligned in the Z-axis direction. Further, a motor (not shown) rotates the spindle 21 so that the surface 11a of the plate 11 faces upward.

  Further, the drive unit 3 of the robot hand 1 rotates the plate 11 so that the first support unit 111 (second support unit 112) faces the opening 4 e of the cassette 4. Further, as shown in FIG. 2, the controller 6 aligns the plate 11 and the wafer W in the Y-axis direction. That is, the plate 11 is driven in the Y-axis direction by the driving unit 3 and the plate 11 is positioned with respect to the wafer W so that the diameter of the wafer W and the perpendicular L2 passing through the midpoint M1 of the line segment L1 overlap. That is, the plate 11 is positioned with respect to the wafer W so that the center Wo of the wafer W is positioned on the perpendicular L2 passing through the midpoint M1 of the line segment L1.

  After the plate 11 is positioned with respect to the wafer W so that the center Wo of the wafer W is positioned on the perpendicular line L2 passing through the midpoint M1 of the line segment L1, the driving unit 3 moves the plate 11 in the −X direction. Thus, the plate 11 enters from the opening 4e to a predetermined position inside the cassette 4. That is, as shown in FIG. 2, the plate 11 is positioned so that the first suction cup 10 a and the second suction cup 10 b are positioned on the outer peripheral portion Wc of the wafer W.

  As shown in FIG. 2, in the robot hand 1, it is not necessary to allow the plate 11 to enter the inner side of the cassette 4. Therefore, the robot hand 1 can easily enter the cassette 4.

  Next, as shown in FIG. 3, the plate 11 is raised to bring the first suction cup 10 a (not shown in FIG. 3) and the second suction cup 10 b into contact with the surface Wa of the wafer W. Further, the suction force generated by the suction of the suction source 12 is transmitted to the contact surface with the wafer W of the first suction cup 10a (second suction cup 10b) through the suction path 13, and the first suction cup 10a. The wafer W is sucked and held by the robot hand 1 by the second sucker 10b adsorbing the surface Wa of the wafer W.

  As the first suction cup 10a and the second suction cup 10b are deformed along the curvature of the surface Wa of the wafer W as shown in FIG. 3, the contact area with the wafer W is maximized. Further, as shown in FIG. 2, the intersection of the short axis extension line 102a passing through the center of the first suction cup 10a and the short axis extension line 102b passing through the center of the second suction cup 10b coincides with the center Wo of the wafer W. Thus, the first suction cup 10a and the second suction cup 10b are in contact with the wafer W such that the long axes 101 and 106 are along the outer periphery Wd of the wafer W. Therefore, in general, the curvature of the wafer W becomes lower as it approaches the outer periphery Wd and the difference in height of the contact position becomes smaller. Therefore, the contact area between the first suction cup 10a and the second suction cup 10b and the wafer W is reduced. The wafer W is adsorbed by the two suction cups 10a and 10b in a state where the gap is maximized and there is no gap. Therefore, the robot hand 1 can prevent the occurrence of a vacuum leak when sucking and holding the wafer W.

  The plate 11 that sucks and holds the wafer W moves in the + X direction, and the wafer W is carried out of the cassette 4 by the robot hand 1.

  When the wafer W is carried out from the cassette 4 by the robot hand 1, the wafer W is curved. Therefore, even if the outer peripheral portion Wc of the wafer W is sucked and held by the two suction cups 10a and 10b, the wafer W hangs down. And will not be deformed.

  Hereinafter, the operation of the robot hand 1 when the wafer W is carried out from the cassette 4 by the robot hand 1 will be described with reference to FIGS. 1 and 4 to 5. Here, the back surface Wb of the wafer W is sucked, that is, the wafer W is sucked and held by bringing the plate 11 closer to the wafer W from the upper side (+ Z direction side).

  First, the Z-axis direction moving mechanism 5 shown in FIG. 1 moves the plate 11 in the Z-axis direction so that the plate 11 and the wafer W in the wafer cassette 4 are aligned in the Z-axis direction. Further, the spindle 21 is rotated by a motor (not shown), and the plate 11 is set so that the surface 11a of the plate 11 faces downward.

  Further, the drive unit 3 of the robot hand 1 rotates the plate 11 so that the first support unit 111 (second support unit 112) faces the opening 4 e of the cassette 4. Further, as shown in FIG. 4, the control unit 6 aligns the plate 11 and the wafer W in the Y-axis direction. That is, the plate 11 is driven in the Y-axis direction by the driving unit 3 and the plate 11 is positioned with respect to the wafer W so that the diameter of the wafer W and the perpendicular L2 passing through the midpoint M1 of the line segment L1 overlap. That is, the plate 11 is positioned with respect to the wafer W so that the center Wo of the wafer W is positioned on the perpendicular L2 passing through the midpoint M1 of the line segment L1.

  After the plate 11 is positioned with respect to the wafer W so that the center Wo of the wafer W is positioned on the vertical line L2 passing through the midpoint M1 of the line segment L1, the driving unit 3 moves the plate 11 in the −X direction. Thus, the plate 11 enters from the opening 4e to a predetermined position inside the cassette 4. That is, as shown in FIG. 4, the plate 11 is positioned so that the first suction cup 10 a and the second suction cup 10 b face the outer peripheral portion Wc of the wafer W.

  As shown in FIG. 4, in the robot hand 1, there is no need to allow the plate 11 to enter the interior of the cassette 4. Therefore, the robot hand 1 can easily enter the cassette 4.

  Next, as shown in FIG. 5, the plate 11 is lowered to bring the first suction cup 10 a and the second suction cup 10 b (not shown in FIG. 5) into contact with the back surface Wb of the wafer W. Further, the suction force generated by the suction of the suction source 12 is transmitted to the contact surface with the wafer W of the first suction cup 10a (second suction cup 10b) through the suction path 13, and the first suction cup 10a. The second suction cup 10b attracts the back surface Wb of the wafer W, whereby the wafer W is sucked and held by the robot hand 1.

  As the first suction cup 10a and the second suction cup 10b are deformed along the curvature of the back surface Wb of the wafer W as shown in FIG. 5, the contact area with the wafer W is maximized. Further, as shown in FIG. 4, the intersection of the short axis extension line 102a passing through the center of the first suction cup 10a and the short axis extension line 102b passing through the center of the second suction cup 10b coincides with the center Wo of the wafer W. Thus, the first suction cup 10a and the second suction cup 10b are in contact with the wafer W such that the long axes 101 and 106 are along the outer periphery Wd of the wafer W. Therefore, in general, the curvature of the wafer W becomes lower as it approaches the outer periphery Wd and the difference in height of the contact position becomes smaller. Therefore, the contact area between the first suction cup 10a and the second suction cup 10b and the wafer W is reduced. The wafer W is adsorbed by the two suction cups 10a and 10b in a state where the gap is maximized and there is no gap. Therefore, the robot hand 1 can prevent the occurrence of a vacuum leak when sucking and holding the wafer W.

  The plate 11 that sucks and holds the wafer W moves in the + X direction, and the wafer W is carried out of the cassette 4 by the robot hand 1.

  When the wafer W is carried out from the cassette 4 by the robot hand 1, the wafer W is curved. Therefore, even if the outer peripheral portion Wc of the wafer W is sucked and held by the two suction cups 10a and 10b, the wafer W hangs down. And will not be deformed.

  The robot hand 1 according to the present invention is not limited to the above-described embodiment, and the size and shape of each component illustrated in the accompanying drawings are not limited to this, and the effects of the present invention are not limited thereto. Can be appropriately changed within a range in which can be exhibited. For example, the first suction cup 10a (second suction cup 10b) is preferably elliptical, but is not limited thereto, and may be circular.

  Further, as shown in FIG. 6, the first suction cup 10a (second suction cup 10b) may be a single suction cup by combining a plurality of (five in the illustrated example) suction cups 100a (100b). When the first suction cup 10 a is configured in this way, each suction cup 100 a (100 b) communicates with the suction source 12 via the suction path 13. Further, for example, the suction cups 100a and the suction cups 100b are disposed at positions symmetrical to the Y axis on the plate 11. The centers of the two suction cups 10a and 10b are determined by selecting the centers of the two suction cups 100a and 100b arranged symmetrically among the suction cups 100a and 100b. Then, a midpoint M2 of a line segment L3 connecting the centers of the two suction cups 10a and 10b is determined.

1: Robot hand 10a: First suction cup 100: Through hole 101: Long axis of first suction cup
102a: Short axis extension line 10b: Second suction cup 105: Through hole 106: Long axis of the second suction cup 102b: Short axis extension line 11: Plate 11a: Plate surface 11b: Plate back face 110: Base
111: 1st support part 111a: 1st suction port 112: 2nd support part 112a: 2nd suction port 12: Suction source 13: Suction path
20: Holder 21: Spindle 22: Spindle housing 3: Drive unit 30: First arm 31: Second arm 32: Plate turning means
33: First arm turning means 34: Second arm turning means 5: Z-axis direction moving means 4: Cassette 4a: Bottom plate 4b: Top plate 4c: Rear wall 4d: Side wall 4e: Opening
40: Shelves 6: Control unit W: Wafer Wa: Wafer surface Wb: Wafer back surface Wc: Wafer outer periphery Wd: Wafer outer periphery Wo: Wafer center L1: Line segment M1: Midpoint of line segment L2: Perpendicular

Claims (1)

A robot hand for carrying out a wafer curved in a bowl shape from a cassette or carrying a wafer curved in a bowl shape into a cassette,
Two suction cups for sucking and holding the outer peripheral portion of the front or back surface of the wafer, a plate in which the two suction cups are spaced apart from each other, a suction path that is provided on the plate and communicates with the suction source; With
The two suction cup is formed in an elliptical shape, provided with a through-hole of elliptical communicating with the suction passage on the vertical line passing through the midpoint of a line segment connecting the centers of the two suction cups, and the two intersection centered positioning the two suction cups robot hand along a periphery of the long axis of the wafer sucking hold the outer peripheral portion of the wafer by the wafer of the extension line of each short-axis of the suction cup.

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