JPH10189700A - Wafer holding mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a wafer holding mechanism which are capable of surely performing a clamping/unclamping action, dispensing with an installation space, making the pinching pawls function surely synchronize with each other, easily regulating a clamping pressure, and generating less dust by a method wherein the pinching pawls are moved by the action of a multi-apex cam at the same time. SOLUTION: A pentagonal cam 2 which is possessed of apexes on its outer circumference and recesses each located between the two adjacent apexes and capable of pivoting to a base 5, an energizing means which energizes a movable pawl toward a wafer pinching side making it bear against the outer circumference of the pentagonal cam 2, a swing arm 7 which rotates the pentagonal cam 2 in one direction and rotates reversely in the opposite direction for recovering so as to move the bearing point of the pentagonal cam 2 which the movable pawl bears against between the apex and recess, and a pull-push wire 1 are provided. The movement of the cable core of the pull-push wire 1 in the lengthwise direction is changed to the movement of the swing arm 7, then the movement of the swing arm is changed to the rotary motion of the pentagonal cam 2, and then the rotary motion of the pentagonal cam 2 is changed to the rectilinear movement of the pinching pawls for chucking or unchucking a wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holding mechanism for holding a semiconductor substrate, a glass substrate, or the like, and more particularly to a holding mechanism for reliably synchronizing the operation of a holding claw for holding a wafer.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor device, a wafer holding mechanism often causes a manufacturing problem. As a conventional wafer holding mechanism, a vacuum chuck type in which one side of a wafer is vacuum-sucked and a grip chuck type in which an outer edge of a wafer is held by a plurality of holding claws are generally used. Each of these methods has advantages and disadvantages, but the former can only process one side without a chuck mechanism during chucking.Therefore, when processing both sides of a wafer simultaneously in one process, the latter grip chuck only A method is used. For example, CCD (Chage Co
Upled Device) In a wafer line etching apparatus, clamping in a vacuum chamber was performed by a five-jaw grip chuck system by controlling five wires.

FIG. 3 is a schematic view showing a wafer chuck mechanism of a conventional wafer holding mechanism. In FIG.
1 is a wire, 32 is a base, and 33 is a holding claw support system. FIG. 4 is a sectional view of the clamping claw support system 33 of the wafer chuck mechanism. The holding claw support system 33 includes a holding claw holder 34, a claw support shaft 35, a holding claw 36, a wire stay 37, and a claw support shaft guide 38. Here, the holding claw holder 34 is fixed to the base 32, and the wire stay 37 is fixed to the holding claw holder 34 with a fastening screw.

[0004] The wire 31 is composed of a flexible guide pipe and a cable core which is also flexible and can move in the length direction in the guide pipe. The cable core passes through a shaft hole formed in the wire stay 37 and a claw support shaft 35.
It is stuck to. The diameter of this shaft hole is such that the cable core passes through but the guide pipe does not.

With this structure, when the cable core is pushed by the other end of the wire 31, this movement is transmitted through the cable core and pushes the claw support shaft 35 in the wire stay 37, and the pinching claw 36 From the outside to the unclamped state. When the cable core is pulled at the other end of the wire 31, the wire stay 37 is pulled by this pull.
The claw support shaft 35 is pulled inside, and the holding claw 36 is attached to the base 3.
2. Pulled back from the outer circumference to the clamped state.

However, in the case of this conventional example, there is not much room for clamping and unclamping due to the relationship with the wafer setting portion, and because of the five-wire and five-claw control, complete synchronization between the movements of each claw is achieved. However, there was a problem that the clamp and unclamping errors could easily occur. In addition, because of wire control, there is a high possibility that the cable core and the guide pipe will slip during operation and generate dust and the like in a vacuum, which may adversely affect product quality. In addition, a plurality of driving wires must be stored in a certain limited place, so that a large storage space is required, and there is a problem that the size cannot be reduced.

[0007]

As described above, in the conventional grip chuck type wafer holding mechanism, there is no room in the clamping mechanism, the operation of the holding claws is poorly synchronized, and clamping and unclamping errors are likely to occur. ,
There are problems that dust is easily generated during the unclamping operation, that the device is relatively large and storage efficiency is low.

In view of this point, the present invention can reliably perform the clamping and unclamping operations, does not require an installation space,
It is an object of the present invention to realize a grip chuck type wafer holding mechanism in which the operation of each of the holding claws can be reliably synchronized, the clamping pressure can be easily adjusted, and the generation of dust is small.

[0009]

To achieve the above object, the present invention provides a holding substrate for holding a wafer, a plurality of holding claws for holding an outer edge of the wafer provided around the outer periphery of the holding substrate, A wafer holding mechanism having at least one of the plurality of holding claws as a movable claw and driving means for driving the movable claw to hold the wafer; A vertex and a multi-vertex cam member having a plurality of concave portions between the plurality of vertices and rotatable with respect to the holding substrate; and Urging means for urging the pinch side of the multi-vertex cam member, and rotating the multi-vertex cam member in one direction so that the contact point of the movable claw to the outer periphery of the multi-vertex cam member moves between the vertex and the concave portion. Equipped with rotation drive means that rotates in the reverse direction And wherein the Rukoto.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a wafer holding mechanism according to the present invention will be described in detail with reference to the accompanying drawings. FIG.
Next, a chuck mechanism of a wafer holding mechanism according to an embodiment of the present invention is shown. In FIG. 1, 1 is a pull / push wire, 2 is a pentagonal cam, 3 is a bearing (large), 4 is a clamping claw driving unit, 5 is a base, 6 is an arm stay, 7 is a swing arm, and 8 is an arm support bolt.・ It is a nut.

FIG. 2 is a cross-sectional view of the holding claw driving section 4. In FIG. 2, 9 is a bearing (small), 10 is a compression coil spring, 11 is a holding claw, 12 is a holding claw holder, 13
Denotes a holding claw slider, 14 denotes a holding claw holding shaft, and 15 denotes a spring holder.

The pull / push wire 1 comprises a flexible guide pipe, like a bicycle brake wire, and a cable core which is also flexible and can move in the guide pipe in the length direction. ing. The cable core is connected to a swing arm 7 fixed to the pentagonal cam 2 through a shaft hole formed in the arm stay 6. The diameter of the shaft hole formed in the arm stay 6 passes through the cable core but does not pass through the guide pipe.

With such a configuration, when one end of the cable core is pushed or pulled, the pushing or pulling motion applied to the one end is used only to deform the shape of the cable core. Instead, it is transmitted to the other end of the cable core as it is to drive the swing arm 7.

The operation of the chuck mechanism will be described with reference to FIGS. In the case of chucking a wafer, when the cable core of the pull / push wire 1 is pulled by a driving system (not shown), the swing arm 7 pulls the pentagonal cam 2 in response to this, and the pentagonal cam 2
It rotates about 30 degrees from the state.

On the other hand, the bearing (small) 9 provided on the pentagonal cam 2 side of the holding claw slider 13 is
The pinching slider 13 is always pressed against the pentagonal cam 2 by the urging force of the compression coil spring 10 provided in the inside 3. Therefore, when the pentagonal cam 2 rotates, the pentagonal cam 2 moves in the circumferential direction of the base 5 following the irregularities of the sides and vertices of the pentagonal cam 2.

That is, in the state of FIG. 1, the bearing (small) 9 and the holding claw slider 13 which are located farthest from the center of the base 5 corresponding to the apex of the pentagonal cam 2 are rotated by the rotation of the pentagonal cam 2. In the right direction in FIG. 2 corresponding to the position of the side of FIG.

When the bearing (small) 9, that is, the holding claw slider 13 moves, the holding claw 11 fixed to the holding claw slider 13 via the holding claw holding shaft 14 also moves toward the center of the base 5. Is performed.

On the other hand, in the case of unchucking of the wafer, a drive system (not shown) pushes the cable core of the pull / push wire 1. Then, the swing arm 7 becomes the pentagonal cam 2
And the pentagonal cam 2 returns to the state of FIG. 1 and stops.

At the position shown in FIG. 1, each apex of the pentagonal cam 2 faces the bearing (small) 9, and the bearing (small) 9 and the holding claw slider 13 are pushed in the left direction in FIG. The holding claw 11 fixed to the claw slider 13 via the holding claw holding shaft 14 is pushed out of the base 5. This releases the chucked wafer. In the chucking and unchucking operations, the pentagonal cam 2 only performs a reciprocating movement of about 30 ° in a reciprocating manner, and does not perform any further rotation. Therefore, there is little fear that the pull / push wire 1 is twisted or entangled.

Thus, in this embodiment, the pull
The movement in the length direction of the cable core of the push wire 1 becomes the movement of the swing arm 7 and is changed into the rotation movement of the pentagonal cam 2, and the rotation movement of the pentagonal cam 2 further converts the five pinching claws 1.
One wafer is changed into a linear motion in the chuck and unchuck directions.

1) Conventionally, since a wire is provided for each of a plurality of holding claws, synchronization is often lost due to wire deterioration, wire position, wire routing, and the like. , The plurality of holding claws are simultaneously moved, so that the operation of each holding claw can be easily synchronized. 2) The strokes of the plurality of holding claws can be made exactly the same. 3) Since there is only one wire, the space from the driving point to the holding mechanism can be reduced. 4) Since there is only one wire, there is no need to distinguish it from other wires, and there is no tangling, so maintenance such as replacement is easy. 5) It was necessary to adjust the operation of the wire and the position of the clamp end and the unclamping end of the gripper for each gripper. However, only one adjustment of the wire operation was required. The adjustment is easy. 6) Similarly, the adjustment of the clamping pressure only needs to be performed once for each of the holding claws, so that the adjustment is easy.

[0022]

EXAMPLE As a result of actually using the embodiment of the present invention described above, the number of occurrences of wafer chuck troubles in the conventional method was slightly less than five on average per month, but was reduced to about 0.4. I was able to dramatically reduce it. In addition, the machine stoppage time due to a wafer chuck trouble can be reduced to only about one hour per month on average, compared to about 84 hours per month in the past. Therefore, it can be understood that, when the embodiment of the present invention is used, even if a wafer chuck trouble has occurred, the time required for repairing the trouble is very short, and the trouble can be easily repaired. Further, the ratio of dust generation is clearly improved as compared with the conventional case, and the average number of dusts is reduced.

Therefore, 1) The reliability of the clamping and unclamping operations by the holding claws is higher than in the conventional method. 2) Since the adjustment of the clamping pressure is easy, damage to the wafer due to the clamping pressure is reduced. 3) Adjustment of the in and out of the nail became easier. This was proved.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, the number of the holding claws is 5 and the multi-vertex cam member is a pentagonal cam. However, the number of the holding claws may be more than 3 or less than 3 or 4. No problem.

In the above embodiment, all the holding claws are movable claws. However, it is possible for only a part of the holding claws to be movable claws. Can be considered.

In the above embodiment, the multi-vertex cam member is driven by the wire means. However, it is of course possible to use a belt, a chain or the like. It is also possible to directly attach a driving means such as a motor.

Further, in the configuration as in the present embodiment, since the holding of the wafer does not always have to be at the horizontal position, it is possible to use the wafer standing upright or to rotate the wafer. , As a holding mechanism.

In the above description, the present invention has been described as being used for holding a wafer. However, it is needless to say that the present invention can be used for holding a substrate not only in a semiconductor wafer but also in a finishing process of a glass substrate, a metal substrate, or the like. Nor.

[0029]

As described above, according to the first aspect of the present invention, a holding substrate for holding a wafer, a plurality of holding claws for holding an outer edge of the wafer provided around the periphery of the holding substrate, and In a wafer holding mechanism having at least one of the plurality of holding claws as a movable claw and driving means for driving the movable claw to hold the wafer, the driving means includes a plurality of vertexes on the outer periphery and A multi-vertex cam member having a plurality of concave portions between a plurality of vertices and rotatable with respect to the holding substrate, and a movable claw being brought into contact with the outer periphery of the multi-vertex cam member,
The multi-vertex cam member is rotated in one direction and restored in the opposite direction so that the urging means for urging the wafer to the clamping side and the contact point of the movable claw to the outer periphery of the multi-vertex cam member move between the vertex and the concave portion. It is characterized by comprising a rotation driving means for rotating. In this way, instead of wires conventionally provided for a plurality of holding claws, it is possible to simultaneously move the plurality of holding claws by the operation of the multi-vertex cam, so that the operation of each holding claw can be easily synchronized and the wire can be easily moved. The problem of synchronization deviation due to the deterioration of the wire, the position of the wire, the routing of the wire, etc. can be solved. In addition, since there is only one wire, the strokes of the plurality of holding claws can be made exactly the same. Furthermore, since there is only one wire, the space from the driving point to the holding mechanism can be reduced. Also, since there is only one wire, there is no need to distinguish it from other wires, and there is no risk of tangling or the like, so maintenance such as replacement of wires is easy. Conventionally, it was necessary to adjust the operation of the wire and the positions of the clamp end and the unclamping end of each of the holding claws. However, only one adjustment of the wire operation was required, and the position of the holding claws was adjusted once. For example, the adjustment is easy. Similarly, the adjustment of the clamping pressure only needs to be performed once for each of the holding claws, so that the adjustment is easy.

According to a second aspect of the present invention, the rotation driving means includes a wire means having one end connected to the multi-vertex cam member;
It is characterized in that it includes a push / pull means for pushing / pulling the other end of the wire means. Thereby, the wafer holding mechanism can be driven from a remote position, the arrangement of the wafer holding mechanism and vacuum sealing can be easily performed, and the cost of the apparatus can be reduced.

According to a third aspect of the present invention, the wire means includes a flexible guide pipe member and a flexible cable core member which moves in the guide pipe member in the longitudinal direction. It is characterized by being performed. As a result, the wafer holding mechanism can be easily driven, arranged and vacuum-sealed from a distant position, and the arrangement and maintenance of the wire means are also easy, so that the apparatus price can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view of a wafer chuck mechanism of a wafer holding mechanism according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a clamping claw driving unit of the chuck mechanism according to the embodiment of FIG.

FIG. 3 is a schematic view of a wafer chuck mechanism of a conventional wafer holding mechanism.

FIG. 4 is a cross-sectional view of a clamping claw support system of a conventional wafer chuck mechanism.

[Explanation of symbols]

1 ... pull push wire, 2 ... pentagonal cam, 3 ...
Bearing (Large), 4 ... Nail driving unit, 5 ... Base, 6 ... Arm stay, 7 ... Swing arm, 8 ...
... Arm support bolt / nut, 9 ... Bearing (small), 10 ... Compression coil spring, 11 ... Nail, 12 ... Nail holder, 13 ... Nail slider,
14 ... Nail holding shaft, 15 ... Spring retainer, 3
1 ... wire, 32 ... base, 33 ... clamping claw support system, 34 ... clamping claw holder, 35 ... clamp support shaft, 36 ...
... Nipping claw 37, Wire stay 38, Claw support shaft guide

Claims (3)

[Claims] 1. A holding substrate for holding a wafer, a plurality of holding claws for holding an outer edge of a wafer provided around an outer periphery of the holding substrate, and a movable claw at least one of the plurality of holding claws. And a driving means for driving the movable claw to hold the wafer, wherein the driving means has a plurality of vertices on an outer periphery and a plurality of recesses between the plurality of vertices. A multi-vertex cam member rotatable with respect to the holding substrate; an urging means for bringing the movable claw into contact with the outer periphery of the multi-vertex cam member and urging the movable claw to a clamping side of the wafer; A rotating drive means for rotating the multi-vertex cam member in one direction and restoring in the opposite direction so that the contact point to the outer periphery of the multi-vertex cam member moves between the vertex and the concave portion. And the wafer holding mechanism. 2. The rotation driving means includes a wire means having one end connected to the multi-vertex cam member, and a push / pull means for pushing / pulling the other end of the wire means. The wafer holding mechanism according to claim 1. 3. The wire means includes a flexible guide pipe member and a flexible cable core member that moves in the guide pipe member in the longitudinal direction. 3. The wafer holding mechanism according to claim 2, wherein: