JP2005131729A - Thin plate material gripping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin plate material gripping device for improving working efficiency, and reducing manufacturing cost, by restraining generation of dust and dirt. <P>SOLUTION: This thin plate material gripping device 3 is arranged in transfer equipment 1 for transferring a thin plate material 5 such as a wafer. The device is composed of a movable member 14 arranged in three places at a substantially equal angle in a transferring member 2 and respectively freely movable in the radial direction, an energizing member 15 for energizing these respective movable members 14 to the inner peripheral side, a cam body 17 rotatably arranged in a central part of the transferring member 2 by a rotational driving means 16b, allowed to abut on the inner end side of the respective movable members 14 and moving the respective movable members 14 in the radial direction, and a gripping means 19 arranged in an outer end near position of the respective movable members 14 and capable of gripping the outer peripheral edge of the thin plate material 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thin plate material gripping device for gripping a thin plate material such as a semiconductor manufacturing wafer or a magnetic disk substrate.

  Conventionally, a wafer transfer robot that transfers a wafer transferred by a wafer transfer robot from a wafer storage cassette that stores a plurality of wafers to a wafer holding stage that measures the flatness of the wafer surface is divided into two transfers. It is composed of a loading arm, a 45-degree arm, and a thin plate material gripping device composed of three finger members that are radially attached to the end of each transfer arm at equal intervals. A gripping claw having the shape is formed.

  When transferring a wafer from a wafer transfer robot to a wafer transfer robot, that is, when transferring a wafer with the finger member in a horizontal state, the wafer transfer robot loaded with the wafer is in a horizontal state. Stop above the member and transfer the wafer. After the transfer, the finger member holding the wafer is switched from the horizontal state to the vertical state by rotating the 45-degree arm of the wafer transfer robot by 180 degrees, and the wafer in the vertical state is transferred to the wafer holding stage. .

  The wafer holding stage includes an annular spindle for rotating the wafer, a wafer flatness measuring sensor for measuring the flatness of the surface of the wafer attached to the spindle, and two fixed holding claws provided on the spindle. , And a movable holding claw that can be moved up and down provided at the lower part of the spindle.

When transferring a wafer to the spindle of the wafer holding stage, that is, when transferring a wafer with the finger member in a vertical state, first, the transfer arm of the wafer transfer robot is lowered to align the axis of the transfer arm. The wafer is positioned below the spindle center, and the movable holding claw is moved to the retracted position (lowered) so as not to prevent the wafer from entering the holding position by the fixed holding claw. When the wafer enters the holding position, the transfer arm is raised to align the axis of the transfer arm with the axis of the spindle, and the lowered movable holding claw is raised to hold the wafer. (For example, Patent Document 1).
Japanese Patent Application No. 2002-067407 JP 2002-307343 A (page 4-6, FIG. 3)

  However, according to the conventional configuration described above, the gripping claws provided at the tips of the finger members are fixed. Therefore, when the wafer is transferred from the wafer transfer robot to the finger member of the wafer transfer robot, When transferring from the finger member of the wafer transfer robot to the spindle of the wafer holding stage, the wafer and the gripping claws of the finger member are rubbed to generate minute dust (also referred to as particles) that adheres to the wafer. Therefore, there is a problem that defective products are generated in the semiconductor element of the wafer.

Further, there is a problem that the life of the gripping claws is shortened due to wear caused by rubbing between the wafer and the gripping claws.
Further, when the wafer is transferred from the wafer transfer robot to the wafer transfer robot, the wafer is placed at a location shifted from the center of the transfer arm (for example, two gripping claws out of three locations). When the wafer is gripped using a fixed gripping claw, the wafer can be gripped by only the two gripping claws without coming into contact with the remaining gripping claw. When the wafer is transferred from the wafer transfer robot to the spindle of the wafer holding stage, accurate transfer (transfer operation) of the wafer is not performed, so that the transfer process is disturbed. There is a problem that the working efficiency is reduced (see Patent Document 1, FIG. 6 (b)).

  In addition, when transferring a wafer from the wafer transfer robot to the spindle of the wafer holding stage, the transfer arm is moved up and down so that the axis of the transfer arm is aligned with the axis of the spindle. There is a problem that the structure of the robot is complicated and the manufacturing cost is high.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a thin plate material gripping device that can suppress the generation of dust to improve work efficiency and can be manufactured at low cost.

  In order to achieve the above object, a thin plate material gripping device according to claim 1 of the present invention is a thin plate material gripping device provided in a transfer device for transferring a thin plate material such as a wafer, and a transfer member. The movable members are arranged at three equal angular intervals and can be moved in the radial direction, the urging members for urging each movable member toward the inner periphery, and the center of the transfer member. A cam body that is rotatably provided by the driving means and abuts on the inner end side of each movable member to move each movable member in the radial direction, and is provided at a position near the outer end of each movable member. And a gripping means capable of gripping the outer peripheral edge of the plate material. As the gripping means, a circular member in which a groove capable of guiding the thin plate material is formed on the outer peripheral surface is used, and provided on at least two movable members. The circular member is configured to be rotatable. Is obtained by it said.

  The thin plate material gripping device according to claim 2 of the present invention is characterized in that a circular member provided on a movable member other than two movable members provided with a rotatable circular member is fixed. is there.

  In the thin plate material gripping device according to claim 3 of the present invention, when the outer peripheral surface of the cam body is rotated in a predetermined direction while the thin plate material is gripped by three circular members, The movable member is shaped so as to be movable toward the inner end side by a predetermined distance.

  Furthermore, the thin plate material gripping device according to claim 4 of the present invention is fixed when the outer peripheral surface of the cam body is rotated in a predetermined direction while the thin plate material is gripped by three circular members. The movable member provided with the circular member is shaped so as to be moved to the inner end side by a predetermined distance.

  Moreover, in the thin plate material gripping device according to claim 5 of the present invention, when the thin plate material gripped by the three gripping means is transferred in a vertical posture, the fixed circular member is positioned at the lower position. It is characterized by that.

  According to the above-described present invention, the circular member of the gripping means provided near the outer end of the movable member is configured to be rotatable while the groove portion capable of guiding the thin plate material is formed on the outer peripheral surface. When the member is brought into contact with the thin plate material, both of them rotate in the circumferential direction, so that the friction between the thin plate material and the circular member is eliminated, and the generation of minute dust can be suppressed. Can be improved.

Further, since the rubbing between the thin plate material and the circular member can be eliminated, wear of the circular member can be avoided, and therefore the life of the circular member can be extended.
Furthermore, when gripping a thin plate material that has been displaced by a thin plate material gripping device, if a circular member provided rotatably is brought into contact with the thin plate material, both rotate in the circumferential direction. Can be moved to the inner end side, so that the thin plate material can be securely held by the three circular members. Thereby, since it can avoid that disorder arises in a transfer process, work efficiency can be improved.

  In addition, when transferring a thin plate material from the transfer robot to the inspection device, conventionally, the center of the thin plate material and the axis of the spindle are aligned by moving the transfer hand up and down. By rotating the cam body, the movable member provided with the fixed circular member is raised to the inner end side in the radial direction by a predetermined distance, so that the center of the thin plate material and the center of the spindle coincide with each other. The structure of the transfer device can be simplified, and thus the manufacturing cost can be reduced.

Hereinafter, a thin plate material gripping apparatus according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a transfer robot (an example of a transfer device) 1 is a semiconductor manufacturing wafer (an example of a thin plate material) 5 that is transferred by a transfer robot (an example of a transfer device) 6. It is transferred to the spindle 8 of the inspection device 7 for measuring the flatness on the surface, and is roughly provided in two transfer hands (an example of a transfer member) 2 and each transfer hand 2. The wafer gripping device 3 is connected to the wafer gripping device 3 (an example of a thin plate material gripping device) and the wafer gripping device 3 and is held by the support member 10 in a 45 degree direction and rotatable about its axis. Is constituted by a rotating shaft body 4 that switches between a horizontal posture and a vertical posture.

  The inspection apparatus 7 includes an inspection unit 9 having an annular spindle 8 that rotates the wafer 5, and a wafer flatness measurement sensor (not shown) that measures the flatness of the surface of the wafer 5 attached to the spindle 8. The two fixed holding claws 41 and one movable holding claw 42 are arranged at substantially equal intervals (120 degree intervals) on the inner peripheral edge of the spindle 8.

  As shown in FIGS. 2 and 3, the wafer gripping device 3 is placed on the upper surface of the transfer hand 2 and is arranged radially at three locations on the outer periphery at regular intervals (120 degree intervals). (Example of support member) Disc-shaped support body 11 having 12 (12a, 12b, 12c), bearing portions 13 (13a, 13b, 13c) respectively provided on the upper surface of each arm portion 12, A rod-like movable member 14 supported by the bearing portion 13 so as to be movable in the radial direction, and one end attached to the lower surface of the movable member 14 (14a, 14b, 14c) and the other end attached to the upper surface of the arm portion 12 A spring (an example of an urging member) 15 (15a, 15b, 15c) for urging 14 to the inner peripheral side, and an output shaft 16a of a motor (an example of a rotation driving means) 16 at the center of the transfer hand 2 It can be rotated freely And a cam body 17 that abuts on the inner end side of each movable member 14 to move each movable member 14 in the radial direction, and an outer peripheral surface of the cam body 17 provided on the lower surface on the inner end side of each movable member 14. The cam follower 18 (18a, 18b, 18c) that abuts and a gripping means 19 (19a, 19b, 19c) that is provided near the outer periphery of each movable member 14 and that can grip the outer periphery of the wafer 5 are configured. Then, the cam body 17 is rotated by the motor 16 and each movable member 14 moves in the radial direction via the cam follower 18 in contact with the cam body 17, thereby holding the wafer 5 by the holding means 19 or holding the wafer 5. Opening is performed. The spring 15c is formed so that the biasing force toward the inner peripheral side from the springs 15a and 15b is weaker.

  As shown in FIG. 4, the gripping means 19 includes a bearing member 21 provided near the outer periphery of each movable member 14, and a plane (including a plane parallel to the wafer 5) that includes the arm portions 12 by the bearing member 21. A circular gripping claw having a shaft 22 rotatably supported around an axis orthogonal to (a) and a groove portion 23 provided rotatably on the shaft 22 and capable of guiding the wafer 5 to the outer peripheral surface ( An example of a circular member) 24. The gripping claws 24 are configured to be rotatable by the gripping claws 24a and 24b and are fixed by the gripping claws 24c.

  As shown in FIG. 5, the bearing portion 13 includes a convex portion 31 provided on the lower surface of each movable member 14, a concave portion 32 provided on the upper surface of each arm portion 12 and capable of guiding the convex portion 31, It is comprised from the ball | bowl 33 for bearings provided between the convex-shaped part 31 and the concave-shaped part 32. FIG.

  The wafer gripping device 3 rotates the cam body 17 to open the wafer 5, to hold the wafer 5 (for example, a position rotated 60 degrees in the predetermined direction from the opened state), and to lift the wafer 5 in a vertical posture ( For example, the cam body 17 can be moved from the center of the cam body 17 to the outside of the cam body 17 in the open state. R1 (first predetermined position) having a maximum length up to the periphery, and R2 ′ (second predetermined position) having a length smaller than R2 in two places and R2 in one place to obtain a gripping state ) And R4 (third predetermined position) having the above length R3 at two locations and the minimum length at one location in order to raise the wafer 5 in the vertical posture. In addition, in order to clearly show the rotational position of the cam body 17 among the three R1s in the open state, a point P is given to one place.

  Further, as shown in FIG. 7, R4 is within the gripping state R2 to R (the distance from the center of the wafer 5 positioned below when being transferred to the inspection apparatus 7 to the axis of the spindle 8). Since it is the length moved to the end side, the relationship R4 = R2-R is established, and R3 is the length moved from the gripping R2 to the outer end side by R3-R2. However, R2 in the expression representing R4 is a distance from the center of the cam body 17 to each cam follower 18 in the gripping state of the wafer 5.

  The shape of the cam body 17 at the second predetermined position where the wafer 5 is held is formed such that the length of R2 ′ is shorter than R2. This is because the position of the movable members 14a and 14b is accurately determined by the cam body 17, and the movable member 14c is forcedly moved to the inner peripheral side by the spring 15c having a weak biasing force toward the inner peripheral side, whereby the wafer 5 is predetermined. This is to hold it in position.

The operation in the above embodiment will be described below.
First, as described above, when the motor 16 is rotated to the position where the first predetermined position of the cam body 17 is brought into contact with each cam follower 18, the cam followers 18a, 18b, 18c move to the outer end side in the radial direction. The members 14a, 14b, and 14c, that is, the gripping means 19a, 19b, and 19c also move to the outer end side in the radial direction. Accordingly, since the gripping claws 24 are opened, the transfer robot 1 loaded with the wafer 5 is stopped above the wafer gripping device 3 of the transfer robot 1 in a horizontal posture, so that the wafer is transferred to the transfer robot 1. 5 transfers can be performed.

  When the wafer 5 is gripped by the gripping claws 24, the cam followers 18a, 18b, and 18c have a radius when the motor 16 rotates the second predetermined position of the cam body 17 to a position where the cam follower 18 comes into contact with the gripper 24 as described above. Therefore, the movable members 14a, 14b, and 14c, that is, the gripping means 19a, 19b, and 19c also move toward the inner end side in the radial direction. Thereby, since the groove part 23 of each holding nail | claw 24 and the outer periphery of the wafer 5 can be contact | abutted, the wafer 5 can be hold | gripped from 3 directions (refer FIG. 2).

  As described above, the gripping claws 24 a and 24 b of the gripping means 19 are configured so as to be rotatable while the groove portion 23 that can guide the wafer 5 is formed on the outer peripheral surface that is a contact surface with the wafer 5. When 24a and 24b are brought into contact with the wafer 5, both of them rotate in the circumferential direction, so that rubbing between the wafer 5 and the gripping claws 24 can be eliminated and generation of minute dust can be suppressed. Thus, the yield can be improved.

Further, since the rubbing between the wafer 5 and the gripping claws 24 can be eliminated, wear of the gripping claws 24 can be avoided, and therefore the life of the gripping claws 24 can be extended.
Incidentally, as shown by a two-dot chain line M in FIG. 6, when the center of the wafer 5 is placed at a position eccentric from the center of the cam body 17, for example, the wafer is located near the two gripping claws 24 b and 24 c. 5 is shifted and when the second predetermined position of the cam body 17 is rotated to a position where it abuts on each cam follower 18 as described above, the gripping means 19a, 19b, 19c Move to. For example, when the groove 23 of the two gripping claws 24b and 24c provided in a freely rotating manner contacts the outer peripheral edge of the wafer 5, the gripping claws 24c rotate in the circumferential direction, so that the wafer 5 holds the remaining gripping. The wafer 5 moves to the claw 24a side, and the wafer 5 can be securely held by the holding claws 24a, 24b, and 24c (see the broken line N in FIG. 6 and FIG. 2). As described above, even if the wafer 5 is placed with being shifted, it is possible to avoid the occurrence of a problem in the transfer process, and thus the work efficiency can be improved.

  As described above, when any one of the gripping claws 24 is fixed, the wafer 5 can be transferred to the inspection apparatus 7 in the same posture and the same position without being fluctuated or rotated during the transfer. For example, a notch (not shown) is provided on the outer peripheral edge of the wafer 5, and the fixed holding claw 41 and the movable holding claw 42 on the inspection apparatus 7 side can accurately hold the wafer 5 due to a difference in fitting shape and the like. Otherwise, the holding position of the wafer 5 may vary or the holding itself may fail. Therefore, stable transfer and measurement can be performed by fixing any one gripping claw 24. It is also possible to know from what position of the wafer 5 the measurement was made.

  As shown in FIG. 7, when the wafer 5 is held by the three holding claws 24 and the cam body 17 is rotated to push up the position of the wafer 5 by the distance R, the holding claws 24a and 24b are moved. Since it is rotatable and the gripping claw 24c is fixed, dust due to rubbing is extremely reduced. This is because the gripping claws 24c and the wafer 5 are in contact with each other but do not move, but if the gripping claws 24a and 24b and the wafer 5 are in contact with each other and are not rotated, rubbing occurs. .

  Furthermore, since the fixed gripping claw 24c is set at the lower position, even if dust is generated by the gripping claw 24c fixed in the worst state, it does not adhere to the wafer 5 and improves the yield of the semiconductor element. Can be achieved.

  After this transfer, the rotary shaft 4 of the transfer robot 1 is rotated 180 degrees to switch the wafer holding device 3 holding the wafer 5 from the horizontal posture to the vertical posture, and the wafer 5 in this vertical posture. Is transferred to the inspection device 7.

  Since the wafer 5 in the vertical posture held by the holding claw 24 is inserted from below into the fixed holding claw 41 of the spindle 8, the center of the wafer 5 at the time of transfer is as shown in FIG. It is in the state located below with respect to the axial center. Under this state, when the motor 16 rotates the third predetermined position of the cam body 17 to a position where it abuts on each cam follower 18 as described above, the gripping means 19c is moved from the center of the wafer 5 positioned below (R). The gripping means 19a, 19b can be moved to the radially outer end side by R3-R2 by the distance to the axial center of the spindle 8, that is, R2-R4). As a result, the center of the wafer 5 is pushed up by the distance R, so that the wafer 5 can be pushed up from the position shown by the broken line X to the position shown by the two-dot chain line Y. Therefore, the center of the wafer 5 and the spindle 8 The axis can be matched.

  Then, as shown in FIG. 8, the wafer 5 is inserted into the fixed holding claw 41 by the pushing-up operation described above to hold the upper edge of the wafer 5, and the lowered movable holding claw 42 is raised to raise the wafer 5 By holding the lower edge of the wafer 5, the entire wafer 5 can be held. Thereafter, as shown in FIG. 9, the cam body 17 is rotated to the first predetermined position, the movable members 14 a, 14 b, 14 c are moved to the outer end side in the radial direction to open the wafer 5, thereby inspecting the inspection apparatus 7. The transfer of the wafer 5 to the substrate can be completed.

  As described above, when the wafer 5 is transferred from the transfer robot 1 to the inspection apparatus 7, conventionally, the center of the wafer 5 and the axis of the spindle 8 are aligned by moving the transfer hand 2 up and down. However, in the present embodiment, by rotating the cam body 17, the movable member 14 c, that is, the gripping means 19 c is moved to the inner end side in the radial direction so that the center of the wafer 5 and the axis of the spindle 8 coincide with each other. Therefore, the structure of the transfer robot 1 can be simplified, and therefore the manufacturing cost can be reduced.

  Needless to say, the wafer 5 is transferred so that the gripping claws 24 of the wafer gripping device 3 and the fixed holding claws 41 and the movable holding claws 42 of the spindle 8 do not come into contact with each other.

  Further, when the wafer 5 having a notch (not shown) provided on the outer peripheral edge is transferred in a vertical posture, the gripping claw 24c is fixed, and the notch on the outer peripheral edge of the wafer 5 is fixed. Can be transferred while the position of the wafer 5 is always kept constant. By transferring to the spindle 8 of the inspection apparatus 7 in this state, the thickness and warpage of the wafer 5 can be accurately measured with the notch as a reference.

  In the above embodiment, when the wafer gripping device 3 is brought into the gripping state, the cam body 17 is rotated 60 degrees from the open state, and when the wafer gripping device 3 is brought into the state where the wafer 5 in the vertical posture is lifted, Although the cam body 17 has been rotated 30 degrees from the gripping state, any angle other than these may be used as long as each of the operating states can be realized.

It is a perspective view of the transfer robot and inspection device concerning an embodiment of the invention. It is a top view of the wafer holding device at the time of wafer holding concerning an embodiment of the invention. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. It is an enlarged view of the B section in FIG. It is CC sectional drawing of FIG. It is a top view at the time of open | release of the wafer holding apparatus which concerns on embodiment of this invention. It is a top view at the time of the movement of the wafer of the perpendicular attitude | position in the wafer holding apparatus which concerns on embodiment of this invention. It is a side view at the time of the movement of the wafer of the perpendicular attitude | position in the spindle which concerns on embodiment of this invention. It is a top view when the wafer of the vertical attitude | position which concerns on embodiment of this invention is open | released from a wafer holding apparatus.

Explanation of symbols

1 Transfer robot (transfer equipment)
3 Wafer gripping device (thin plate material gripping device)
5 Wafer (thin plate)
7 Inspection device 8 Spindle 12 (12a, 12b, 12c) Arm part (support member)
14 (14a, 14b, 14c) Movable member 15 (15a, 15b, 15c) Spring (biasing member)
17 cam body 18 (18a, 18b, 18c) cam follower 19 (19a, 19b, 19c) gripping means 24 (24a, 24b, 24c) gripping claw (circular member)
41 Fixed holding claw 42 Movable holding claw

Claims (5)

A thin plate gripping device provided in a transfer device for transferring a thin plate material such as a wafer,
A movable member disposed at three positions at substantially equal angles on the transfer member and movable in the radial direction;
A biasing member that biases each of these movable members toward the inner periphery;
A cam body which is rotatably provided at the center of the transfer member by a rotation driving means and abuts on the inner end side of each movable member to move each movable member in the radial direction;
It is composed of gripping means provided near the outer end of each movable member and capable of gripping the outer peripheral edge of the thin plate material,
A thin plate material characterized in that a circular member in which a groove capable of guiding a thin plate material is formed on the outer peripheral surface is used as the gripping means, and the circular member provided on at least two movable members is configured to be rotatable. Gripping device.   2. The thin plate material gripping device according to claim 1, wherein a circular member provided on a movable member other than the two movable members provided with a rotatable circular member is fixed.   When the cam body is rotated in a predetermined direction with the thin plate material held by three circular members on the outer peripheral surface of the cam body, the predetermined movable member can be moved to the inner end side by a predetermined distance. The thin plate material gripping device according to claim 1, wherein   When the cam body is rotated in a predetermined direction with the thin plate material held by the three circular members on the outer peripheral surface of the cam body, the movable member provided with the fixed circular member is moved to the inner end by a predetermined distance. The thin plate material gripping device according to claim 2, wherein the thin plate material gripping device has a shape that can be moved sideways.   4. The thin plate material gripping apparatus according to claim 3, wherein when the thin plate material gripped by the three gripping means is transferred in a vertical posture, the fixed circular member is in a lower position. .

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