JP2002170862A - Wafer holding device - Google Patents

Abstract

(57) [Problem] To provide a wafer holding device capable of holding the center of a wafer at a fixed position with respect to the wafer holding device even if the diameter of the wafer varies. A driving means having a flat base member, a movable member attached to a base portion of the base member, and movable in the longitudinal direction of the base member, and fixed to the movable member. A first gripping claw 5 and a second gripping claw 6 attached to the distal end portion of the base member 3 so as to be able to advance and retreat, and connected to the moving member 4A via a link mechanism 7 are provided. 3 from the base to the tip, the first and second gripping claws 5, 6
And the first and second gripping claws 5 and 6 move the wafer W
Is pressed to grip the wafer W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer holding device which is attached to a tip of an arm of a robot for transferring a wafer in a semiconductor manufacturing apparatus or between semiconductor manufacturing apparatuses. The present invention relates to a wafer holding device for supporting a wafer.

[0002]

2. Description of the Related Art As a device for holding a wafer, which is attached to the tip of an arm of a wafer transfer robot,
2. Description of the Related Art There has been conventionally known a structure in which a peripheral portion of a wafer is gripped to support the wafer. FIG. 4 shows a first conventional example of such a wafer holding device. In the figure, 1
Is a robot arm, and 2 'is a wafer holding device attached to the robot arm 1. The wafer holding device 2 ′ is attached to a thin plate-shaped base material 3 and the base material 3,
A driving means 4 having a movable element 4A which can move forward and backward, a movable claw 21 fixed to the moving element 4A of the driving means 4 and pressing a peripheral portion of the wafer toward a front end portion of the base material 3; The base 3 includes fixed claws 22 and 22 ′ fixed to the portion, and a plurality of support seats 16 provided on a surface of the base material 3 facing the back surface of the wafer W and supporting the back surface of the wafer W. First, the wafer gripping device 2 ′ is configured such that the distance between the movable claw 21 and the fixed claws 22, 22 ′ is widened so that the wafer W can be inserted, and the wafer is held between the movable claw 21 and the fixed claws 22, 22 ′. W is inserted and placed on the support seat 16, and then, the movable member 4A of the driving means 4 is driven to push the movable claw 21 against the peripheral portion of the wafer W to push out the wafer W. The fixed nails 22 and 22 'receive the peripheral edge of the wafer W, and the movable nail 21 and the fixed nails 22 and 22'
Is to be gripped. Next, as a second conventional example, a wafer holding device described in Japanese Patent Application Laid-Open No. 4-343448 will be described. The apparatus includes a first movable finger that can move in a longitudinal direction, a supporting claw that is rotatably attached to a tip end of the first movable finger, abuts on an end surface of the wafer and supports the wafer, and a parallel with the first movable finger. A second movable finger, a supporting claw rotatably attached to a tip end of the second movable finger, abutting against the wafer end surface to support the wafer, and a supporting claw of the first movable finger pressing the wafer end surface to form the second movable finger. (2) A first movable finger drive mechanism for abutting the wafer end surface on the support claw of the movable finger and holding the wafer between the support claws of the first and second movable fingers. The support of the wafer by this device firstly
With the spacing between the support claws of the first and second movable fingers widened to allow insertion of the wafer, the wafer is inserted between the support claws of the first and second movable fingers, and then the first movable finger is moved. By driving the finger driving mechanism, the supporting claws of the first movable finger are brought into contact with the wafer and drawn, and furthermore, are brought into contact with the supporting claws of the second movable finger so that the wafer is sandwiched between the supporting claws.

[0003]

However, the conventional wafer holding apparatus as described above has the following problems. First, in the case of the first conventional example, the movable claw 21
When the wafer W is gripped by narrowing the distance between the and the fixed claws 22 and 22 ′, only the movable claw 21 is driven to push the wafer W toward the fixed claws 22 and 22 ′ and grip the wafer W. If there is variation, the center position of the wafer W varies with respect to the reference position of the wafer support device due to the gripped wafer W. For this reason, when the wafer W is mounted on the transfer destination, there is a problem that the mounting position is shifted due to the wafer W. When the gripping state is released by widening the gap between the movable claw 21 and the fixed claws 22, 22 ', only the movable claw 21 moves, so that the fixed claws 22, 22' are kept in contact with the peripheral edge of the wafer W. is there. Therefore, if the wafer W is placed on the transfer destination in this state, the wafer W and the fixed claws 22, 22 'are rubbed with each other, so that particles are generated and the wafer W is contaminated. In the second conventional wafer holding device, the second movable finger is movable, but the wafer is drawn by the first movable finger, and is passively movable when the wafer and the supporting claw of the second movable finger come into contact with each other. Since the supporting claws of the second movable finger remain in contact with the peripheral edge of the wafer when the gripping state is released, particles are generated due to friction between the wafer and the supporting claws as in the first conventional example. There was a problem. SUMMARY OF THE INVENTION It is an object of the present invention to provide a wafer holding device that can hold a wafer at a fixed position with respect to the wafer holding device even if the diameter of the wafer varies.

[0004]

According to a first aspect of the present invention, there is provided a wafer holding apparatus which is attached to a tip of a wafer transfer robot and holds a wafer. A driving unit having a base member, a movable member attached to a base portion side of the base member and capable of moving back and forth in a longitudinal direction of the base member, a first gripping claw fixed to the movable member, A second gripper is attached to the tip of the material so as to be able to advance and retreat, and the movable element is connected to the movable element via a link mechanism. By moving the movable element from the base of the base material to the distal end, The first and second gripping claws are interlocked, and the first and second gripping claws press the peripheral edge of the wafer to grip the wafer. Further, the invention according to claim 2 is the same as the invention according to claim 1.
In the wafer holding device according to the above, while the link mechanism is fixed to the mover, a connection bar having a long hole at the end, and a fulcrum pin provided on the base material can be rotated about a fulcrum pin, both ends A link having first and second node pins, and a rod having an elongated hole at one end and the other end fixed to the second gripping claw, wherein the first node pin of the link is The second node pin of the link is inserted into the elongated hole of the rod, and the second node pin of the link is inserted into the elongated hole of the rod. According to a third aspect of the present invention, in the wafer holding device according to the first or second aspect, a plurality of support seats for supporting the back surface of the wafer are provided on a surface of the base material facing the back surface of the wafer. It is configured. Further, the invention described in claim 4 is the same as the claim 1.
4. The wafer holding device according to any one of items 1 to 3,
A groove having a V-shaped cross section or a rectangular cross section is formed on a surface of the first and second gripping claws which abuts on the wafer.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an embodiment of the present invention. In the figure, reference numeral 1 denotes a robot arm of a wafer transfer robot, and reference numeral 2 denotes a wafer holding device attached to a tip of the robot arm 1. Wafer holding device 2
Has a base material 3 made of a thin flat plate having a bifurcated tip. 4 is a driving means 4 attached to the base side of the substrate 3
The driving means 4 includes a movable member 4A which freely moves from the root of the base material 3 toward the front end thereof. Drive means 4
For example, a pneumatic air cylinder, an electromagnetic linear motor, an ultrasonic linear motor, or the like can be used. A first gripper 5 for pressing the peripheral portion of the wafer W toward the distal end of the base material 3 is fixed to the movable element 4A. Second gripping claws 6, 6 'for pressing the peripheral portion of the wafer W to the side are attached. 7, 7 'connects one end to the mover 4A,
This is a link mechanism having the other end connected to the second gripping claws 6, 6 '. The link mechanisms 7, 7 'respectively include a connecting bar 8 fixed to the mover 4A, rods 9, 9' connected to the second gripping claws 6, 6 ', and a fulcrum pin 10 provided on the base material 3. , 1
A link 13, which is rotatable about 0 'and has first and second nodal pins 11, 11', 12, 12 'at both ends;
13 '. One end of each of the links 13, 13' is connected to the first node pin 11, 11 'by the connecting bar 8, 8'.
Into the elongated hole at the end of the
The other ends of the third and third nodes 13 and 13 'are connected by inserting the second node pins 12 and 12' into elongated holes formed in one ends of the rods 9 and 9 '. In addition, the second gripping claws 6, 6 'are
By supporting 9 'with guides 14, 14, 15, 15', it is possible to advance and retreat only in the longitudinal direction of rods 9, 9 '. Reference numeral 16 denotes a plurality of support seats provided on a surface of the base material 3 facing the back surface of the wafer W and supporting the back surface of the wafer W.

Next, the operation of the wafer holding device 2 configured as described above will be described. First, the position of the moving element 4A is adjusted to make the first and second gripping claws 5, 6, 6 '.
The wafer W is expanded so that the wafer W can be inserted therebetween. In this state, the wafer W is held by the first and second gripping claws 5, 6,
6 ', and is placed on the support seat 16 to move the moving element 4A of the driving means 4 in the direction of the distal end of the substrate 3, that is, in the direction of 17A in FIG. At this time, the first gripper 5
Is directly fixed to the moving element 4 and moves together with the moving element 4 in the direction of 17A. At the same time, since the second gripping claws 6, 6 'are connected to the moving element 4A via the link mechanisms 7, 7', when the moving element 4 moves in the direction of 17A, it moves in the direction of 18A in FIG. Moving. Therefore, as the moving element 4A moves in the direction of 17A, the distance between the gripping claws 5, 6, and 6 'narrows, and the respective gripping claws come into contact with the peripheral portion of the wafer W, and the wafer W is gripped. Is done. The release of the gripped wafer is the reverse of the gripping operation described above. When the moving element 4A of the driving means 4 is moved toward the base of the base material 3, that is, in the direction of 17B in FIG. 6 'is widened, and the grip of the wafer W is released. By moving the moving element 4A in the direction of 17A in this manner, the first and second gripping claws 5, 6, 6 are formed.
6 'interlocks and all the gripping claws move to grip the wafer W, so that the wafer W is not gripped after leaning toward one gripping nail side. Therefore, even if the diameter of the wafer W varies, the wafer gripping device 2
The center position of the wafer W is constant with respect to a certain reference position, and the wafer W can be accurately placed on the transfer destination. Further, when the wafer W is gripped, the wafer W is once placed on the support seat 16 provided on the base material 3, and then the moving member 4A of the driving means 4 is driven to grip the wafer W. For the second gripping claws 5, 6, 6 ',
The position of the wafer W is always kept constant, the wafer W can be securely held, and the transfer reliability is improved. When the gripping state of the wafer W is released, the driving means 4
By moving the mover 4A in the direction of 17B,
The first and second gripping claws 5, 6, 6 ′ are interlocked, and all the gripping claws avoid the wafer W. Therefore, when the wafer W is placed on the transfer destination, the wafer W and the holding claws 5,
Since 6,6 'does not rub, no particles are generated and the wafer W is not contaminated.

FIG. 2 shows a wafer gripping device 2 taken along line XX of FIG.
FIG. 3 is a cross-sectional view taken along the line YY similarly. As shown in FIG. 2 and FIG. 3, grooves having a V-shaped cross section are formed on the surfaces 5A, 6A, 6A 'of the first gripping claws 5 and the second gripping claws 6, 6' which are in contact with the wafer W. are doing. This groove may be a groove having a rectangular cross section having a width obtained by adding some allowance to the thickness of the wafer. When the wafer W is gripped by the wafer gripping device 2, the grooves formed on the 5, 6, and 6 'surfaces of the first and second gripping claws engage with each other, so that the wafer W is horizontal. It is restricted not only in the direction but also in the vertical direction. Therefore, the position of the wafer W in the vertical direction is always kept constant, and there is no danger of the wafer W dropping, and the reliability of the transfer is improved. In addition, since there is no danger of the wafer W dropping, it is easy to transport the wafer W in a vertical state or to turn the wafer W upside down. On the other hand, the gripping state of the wafer W is released and the wafer W is released.
Is placed, all the gripping claws move away from the wafer W, so that there is no engagement between the wafer W and the grooves of the gripping claws 5, 6, 6 '. Therefore, there is no problem that particles are generated due to the rubbing of the wafer W.

[0008]

As described above, the present invention has the following effects. According to the first or second aspect of the present invention, by moving the moving element forward, the first and second gripping claws interlock and grip the wafer, so that the wafer is drawn to one gripping nail side. There is no gripping. Therefore, even if the diameter of the wafer varies, the center position of the wafer is constant with respect to the reference position of the wafer holding device, and the wafer can be accurately placed on the transfer destination. Also, when releasing the gripping state of the wafer, by retracting the moving element of the driving means,
The first and second gripping claws interlock and avoid. Therefore, when the wafer is placed on the transfer destination, there is no friction between the wafer and the gripping claws, so that no particles are generated and no contamination of the wafer by the particles occurs. According to the invention described in claim 3, in addition to the effects of the invention described in claim 1 or 2, when the wafer is gripped, the wafer is once placed on the support seat provided on the base material, and then the wafer is removed. Since the wafer can be gripped, the position of the wafer in the vertical direction is always kept constant with respect to the first and second gripping claws, the wafer can be gripped reliably, and the transport reliability is improved. According to the invention described in claim 4, in addition to the effects of the invention described in any one of claims 1 to 3, when the peripheral portion of the wafer is gripped by the first and second gripping claws, the peripheral edge of the wafer is gripped. The portion engages with a groove having a V-shaped cross section or a rectangular cross section formed on the first and second gripping claws, and the wafer is restrained not only in the horizontal direction but also in the vertical direction. Therefore, the position of the wafer in the vertical direction is always kept constant, the danger of the wafer dropping is eliminated, and the reliability of the transfer is improved. In addition, it becomes easy to transfer the wafer in a vertical state, or to place the wafer upside down.

[Brief description of the drawings]

FIG. 1 is a plan view of a wafer holding device according to an embodiment of the present invention.

FIG. 2 shows a wafer holding device according to an embodiment of the present invention in FIG.
FIG. 3 is a sectional view taken along line XX in FIG.

FIG. 3 shows a wafer holding device according to an embodiment of the present invention;
FIG. 3 is a sectional view taken along line YY in FIG.

FIG. 4 is a plan view of a wafer holding device showing a first conventional example.

[Explanation of symbols]

1: Robot arm 2, 2 ': Wafer holding device 3: Base material 4: Driving means 4A: Moving element 5: First holding claw 6, 6': Second holding claw 7, 7 ': Link mechanism 8: Connection bar 9: rod 10: fulcrum pin 11: first node pin 12: second node pin 13: link 14, 15: guide 16: support seat 17A, 17B: mover or first gripping claw Movement direction 18A, 18B: Movement direction of second gripping claw 21: Movable claw 22, 22 ': Fixed claw W: Wafer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C007 DS01 ES04 ET08 EU07 EV07 EW03 HS12 HS24 NS09 NS11 NS17 3F061 AA01 BA04 BB08 BC09 BD01 BD05 BE12 BF04 DB00 DB04 DB06 5F031 CA02 FA01 FA07 GA06 GA10 GA13 GA14 GA15 GA15 PA26

Claims (4)

[Claims] 1. A wafer holding device attached to a tip portion of a wafer transfer robot to hold a wafer, wherein the wafer holding device is attached to a flat base material and a base portion side of the base material,
A driving unit having a movable member that is movable back and forth in the length direction of the base material, a first gripping claw fixed to the movable member, and a movable member that is attached to a front end portion of the base material so as to be movable forward and backward. A second gripping claw connected to the first and second gripping claws by moving the moving element from the base of the base material to the tip of the base member, thereby interlocking the first and second gripping claws. A wafer gripping device characterized in that the wafer is gripped by pressing a peripheral portion of the wafer with a second gripping claw. 2. The link mechanism is fixed to the mover, is rotatable around a connecting bar having a long hole at a tip thereof, and a fulcrum pin provided on the base material, and has first and second ends at both ends. And a link having a second node pin, and a rod having an elongated hole at one end and the other end fixed to the second gripping claw, wherein the first node pin of the link is provided at the tip of the connection bar. The wafer holding device according to claim 1, wherein the second node pin of the link is inserted into the elongated hole, and the second node pin of the link is inserted into the elongated hole of the rod. 3. The wafer according to claim 1, wherein a plurality of support seats for supporting the back surface of the wafer are provided on a surface of the base material facing the back surface of the wafer. Gripping device. 4. The method according to claim 1, wherein the first and second gripping claws are formed with grooves having a V-shaped cross section or a rectangular cross section on a surface that contacts the wafer, respectively. The wafer holding device according to any one of the above.