JP2004266202A - Holding mechanism of workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To clamp a workpiece properly by a means of a simple structure while minimizing the possibility of damaging the workpiece. <P>SOLUTION: In a holding mechanism A of a workpiece, a workpiece W is clamped between s stopper surface 23A of a first supporting part 2A and a push means 3 by putting the workpiece W on upper surfaces 22A, 22B of first and second supporting parts 2A, 2B and pushing and moving it from the second supporting part 2B side to the first supporting part 2A side by the push means 3. The upper surfaces 22A, 22B of the first and second supporting parts 2A, 2B are tilting surfaces which are lower as they get close to a central part between the first and second supporting parts 2A, 2B and a tilting angle of the upper surface 22B is larger than a tilting angle of the upper surface 22A. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a workpiece holding mechanism suitable for use as a robot handling device for handling a workpiece such as a wafer.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an example of this type of workpiece holding mechanism, there is a mechanism described in Japanese Patent Application Laid-Open No. H11-157572. As shown in FIG. 4, the conventional holding mechanism includes a plurality of support portions 91 provided on an upper surface of a base plate 90 and a work piece W mounted on the plurality of support portions 91 at an edge of a front end of the base plate 90. A pair of pushing members 92 for pushing toward the portion 90a. By pushing the base plate 90 in the direction of the arrow Na by the pair of pushing members 92, the base plate 90 can be clamped and fixed between the pair of pushing members 92 and the edge 90a of the base plate 90. .
[0003]
[Patent Document 1]
JP 2000-308988 A
[Problems to be solved by the invention]
When handling the workpiece W, it is sufficient to prevent dirt and scratches from being made on various parts such as the front surface and the back surface, or to generate dust such as shaving powder due to the semiconductor wafer being scraped. May need to be considered. In particular, when the workpiece W is a wafer used for manufacturing semiconductor devices, more careful handling is required.
[0005]
However, in the above-described related art, when the workpiece W is pushed by the pair of pushing members 92, the back surface of the workpiece W rubs against the plurality of support portions 91. Therefore, there is a problem that the back surface of the workpiece W is scraped, and this portion is damaged or dust such as shaving powder is generated. Patent Literature 1 also discloses a technique for reducing the contact friction force between the workpiece W and the support portion 91 by using a rotatable ball member as the support portion 91. The parts cost is high, resulting in cost disadvantages. In addition, a maintenance burden for maintaining the function of the ball member so that the ball member can always rotate smoothly increases.
[0006]
The present invention has been conceived under such circumstances, and it is possible to appropriately hold the workpiece by means of a simple structure while minimizing the risk of damage to the workpiece. The challenge is to be able to do that.
[0007]
DISCLOSURE OF THE INVENTION
In order to solve the above problems, the present invention employs the following technical means.
[0008]
The workpiece holding mechanism provided by the present invention includes a first support portion having an upper surface on which a part of the outer peripheral edge of the workpiece is placed, and a stopper surface rising above the upper surface; A second support portion provided at a distance from the support portion and having an upper surface on which another part of the outer peripheral edge of the workpiece is placed; and a second support portion provided between the first and second support portions. On the upper surface, the second support portion can be pushed from the second support portion side to the first support portion side, and a part of the outer peripheral surface of the workpiece is brought into contact with a stopper wall of the first support portion. And a pushing means for clamping the workpiece by the first and second support portions, wherein upper surfaces of the first and second support portions are respectively provided on the first and second support portions. Central part between clubs The height of the upper surface of the second support portion is larger than the angle of the upper surface of the first support portion. I have.
[0009]
According to such a configuration, when the workpiece is placed on the upper surfaces of the first and second support portions and is pushed from the second support portion side to the first support portion side by the pushing means, The workpiece is clamped between the pushing means and the stopper surface of the first support, and is appropriately fixed and held. Since the upper surfaces of the first and second support portions are both inclined surfaces, when a workpiece is placed on these upper surfaces, the upper surface and the outer peripheral edge of the workpiece can be brought into point contact. Such a point contact state is maintained even when the workpiece slides on the upper surface by being pushed by the pushing means. Therefore, the contact area between the workpiece and the first and second support portions is extremely reduced, and the contact between the workpiece and a portion other than the outer peripheral edge does not occur. It can be properly fixed and held by not connecting.
[0010]
Further, as an important effect, in the present invention, since the inclination angle of the upper surface of the first support portion is smaller than the inclination angle of the upper surface of the second support portion, the workpiece is not supported by the first and second support portions. When sliding on the upper surface of the first support portion from the second support portion side, the resistance of the upper surface of the first support portion to this sliding operation can be reduced. On the other hand, since the inclination angle of the upper surface of the second support portion is relatively large, an effect of promoting the operation of sliding the workpiece toward the first support portion can be obtained. Thus, in the present invention, the operation when the workpiece slides on the first and second support portions can be facilitated, and generation of shavings due to friction can be appropriately suppressed. . In the present invention, the upper surfaces of the first and second support portions may be simply formed as inclined surfaces, and unlike the means for rotatably providing the ball member in Patent Document 1, unlike the first and second support portions. Since it is not necessary to operably provide all or a part of the unit, its manufacture is easy, and there is an advantage that the manufacturing cost can be reduced. Also, maintenance is easy.
[0011]
In a preferred embodiment of the present invention, a plurality of the first and second support portions are provided. According to such a configuration, it is possible to stably support the workpiece while reducing the width of each of the first and second support portions. Therefore, the contact area with the work piece can be reduced, and the possibility that the work piece is damaged or rubbing powder is generated can be further reduced.
[0012]
In a preferred embodiment of the present invention, the work piece is a disk shape or a disk shape having a notch at an outer peripheral edge thereof, and a surface of the pushing means which contacts the outer peripheral edge of the workpiece is , A flat curved surface, a convex curved surface, or a concave curved surface having a larger radius of curvature than the outer peripheral surface of the workpiece. According to such a configuration, it is possible to reduce the contact area between the pushing means and the outer peripheral surface of the workpiece by making the point contact or near contact with the point. Therefore, it is suitable for further reducing the possibility that the work piece is scratched.
[0013]
In a preferred embodiment of the present invention, the stopper surface of the first support portion is a flat surface, a convex curved surface, or a concave curved surface having a larger radius of curvature than the outer peripheral surface of the workpiece. According to such a configuration, the contact between the stopper surface and the outer peripheral surface of the workpiece is also set to a point contact or a contact state similar thereto, thereby reducing the contact area thereof and preventing the workpiece from being damaged. It can be prevented more thoroughly.
[0014]
In a preferred embodiment of the present invention, the position of at least one of the first and second support portions is freely changeable so that the distance between them can be changed. According to such a configuration, by adjusting the position of at least one of the first and second support portions, a plurality of types of workpieces having different outer diameters can be supported and fixedly held.
[0015]
Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.
[0017]
1 and 2 show an example of a workpiece holding mechanism according to the present invention. The workpiece holding mechanism A of the present embodiment is a mechanism for clamping and holding a semiconductor wafer W having a diameter of, for example, 300 mm, and as is well shown in FIG. It is configured to include second support portions 2A and 2B and a pair of pushers 3. A notch (orientation flat) is formed on the outer peripheral edge of the wafer W, but is omitted in the drawing.
[0018]
The base plate 1 is formed of, for example, a plate made of carbon fiber reinforced plastic, and a robot arm 8 is attached to a base end (the right side in FIG. 1). As this robot, for example, a multi-axis / multi-joint type robot that allows the arm 8 to move in three-dimensional x, y, and z-axis directions is used, but is not limited to this. The holding mechanism A of the present embodiment functions as a handling mechanism of the robot. In order to reduce the weight, the base plate 1 has a vertical width smaller than the diameter of the wafer W, and a region near the front end of the base plate 1 has a bifurcated shape.
[0019]
The first and second support portions 2A, 2B are provided by attaching chip-like members 20A, 20B separate from the base plate 1 to the base plate 1 using bolts 21 or the like. The material of the chip-shaped members 20A and 20B is, for example, PEEK (polyether ether ketone) as a material having high mechanical strength such as impact resistance and excellent fatigue resistance and environmental resistance. I have. The pair of first support portions 2A are provided on the two distal end portions of the base plate 1, and the pair of second support portions 2B are provided on the upper surface of the base plate 1 near the base end portion. The first and second support portions 2A and 2B are arranged to be able to support four locations on the outer peripheral edge of the wafer W. The arrangement is symmetrical with respect to the center line L shown in FIG.
[0020]
The first and second support portions 2A and 2B have upper surfaces 22A and 22B on which the outer peripheral edge of the wafer W is placed, and stopper surfaces 23A and 23B rising from the upper surfaces 22A and 22B. 2, the upper surfaces 22A and 22B are both flat inclined surfaces whose height decreases toward the center of the base plate 1. As shown in FIG. However, the inclination angle β of the upper surface 22B is larger than the inclination angle α of the upper surface 22A. Preferably, the inclination angle α is 6.0 to 7.0 degrees, while the inclination angle β is 9.0 to 12.0 degrees. The stopper surfaces 23A and 23B are surfaces for preventing the wafer W placed on the upper surfaces 22A and 22B from falling off from those portions, and have appropriate heights. These stopper surfaces 23A and 23B are flat surfaces, convex curved surfaces, or concave curved surfaces having a larger radius of curvature than the outer peripheral surface of the wafer W, so that point contact with the outer peripheral edge of the wafer W is possible. (However, the contact state in plan view is point contact, and in the thickness direction of the wafer W, it is a line contact state in which the contact points extend).
[0021]
The pair of pushers 3 are for pushing the wafer W, are located in the vicinity of the second support 2B, and are provided symmetrically with respect to the center line L. The pushing body 3 is attached to a reciprocating rod 31a of an air cylinder 31 provided in a region near the base end of the base plate 1, and is capable of reciprocating in the direction of the arrow N1 (the direction in which the center line L extends). Similarly to the stopper surfaces 23A and 23B, the distal end surface 30 of the pushing body 3 for making contact with the wafer W also has a flat surface, a convex curved surface, or a concave surface having a larger radius of curvature than the outer peripheral surface of the wafer W. It is a curved surface. The pusher 3 is made of PEEK, for example, like the first and second support portions 2A and 2B.
[0022]
Next, the operation of the workpiece holding mechanism A having the above configuration will be described.
[0023]
First, in order to hold the wafer W, the wafer W is placed on the upper surfaces 22A and 22B of the first and second support portions 2A and 2B. Since the upper surfaces 22A and 22B are inclined surfaces, The outer peripheral edge of the wafer W and the upper surfaces 22A and 22B are in a point contact state. The outer peripheral edge of the wafer W is generally rounded, but even with such a rounded shape, the contact with the inclined upper surfaces 22A and 22B is a point contact. Become. Therefore, the contact area of the first and second support portions 2A and 2B with the back surface of the wafer W can be reduced, and the wafer W can be prevented from being stained.
[0024]
Next, the pair of pushers 3 is advanced toward the first support 2A. As a result, the wafer W is pushed and the two outer peripheral edges thereof come into contact with the stopper surfaces 23A of the pair of first support portions 2A, and the wafer W is clamped by the stopper surface 23A and the pair of pushing members 3. Will be held. By holding the wafer W in this manner, the robot arm 8 can be moved in various directions to transfer the wafer W to a desired position. When the pushing body 3 is retracted, the holding state of the wafer W is released, and the wafer W can be taken out from the holding mechanism A.
[0025]
The wafer W slides on the upper surfaces 22A, 22B of the first and second support portions 2A, 2B when being pushed by the pusher 3, but the wafer W has a small inclination angle α of the upper surface 22A. The resistance when the outer peripheral edge slides in the direction of the arrow N2 in FIG. 2 on the upper surface 22A toward the stopper surface 23A can be reduced. On the other hand, since the inclination angle β of the upper surface 22B is large, the outer peripheral edge of the wafer W easily slides on the upper surface 22B in the direction of the arrow N2. Therefore, no large frictional force is generated between the outer peripheral edge of the wafer W and the upper surfaces 22A and 22B, and generation of dust such as shavings is suppressed. Even when the outer peripheral edge of the wafer W slides on the upper surfaces 22A and 22B, they keep a point contact state, so that no abrasion or the like is generated near the outer peripheral edge of the wafer W. . The pushing body 3 pushes the outer peripheral surface of the wafer W in a state of contact with the planar viewpoint, and when the wafer W is clamped, the distal end face 30 of the pushing body 3 and the stopper surface of the first support 2A. 23A and the outer peripheral surface of the wafer W are also in a plane-view contact state, so that the pressing body 3 and the stopper surface 23A stain the outer peripheral surface of the wafer W or damage parts other than the outer peripheral surface. This is also properly suppressed.
[0026]
As described above, according to the holding mechanism A of the present embodiment, it is possible to fix and hold the wafer W such that the constituent members of the holding mechanism A do not touch the outer peripheral edge or the portion other than the outer peripheral surface of the wafer W at all. It is possible to prevent the wafer W from being damaged or stained. The first and second support portions 2A, 2B are merely configured by attaching chip-shaped members 20A, 20B to the base plate 1, and are, for example, means for rotatably attaching a ball member described in Patent Document 1. The cost is lower than that of, and the maintenance is easy. Further, since the pair of pushing members 3 and the two stopper surfaces 23A are symmetrical with respect to the center line L, when the pushing member 3 is advanced and the wafer W is clamped, the center of the wafer W becomes two stopper surfaces 23A. A so-called centering function to be adjusted to a predetermined position based on the reference is also suitably obtained.
[0027]
FIG. 3 shows another embodiment of the present invention. In the figure, the same or similar elements as in the above embodiment are denoted by the same reference numerals as in the above embodiment.
[0028]
In the embodiment shown in FIG. 3, the number of the second support 2B is one, and the position of the second support 2B is freely adjustable in the direction of the arrow N3. As means for this, for example, a hole 28 through which a bolt 29 for fixing the chip-shaped member 20B constituting the second support portion 2B is inserted is formed in an elongated hole, and a fastening nut screwed to the bolt 29 is used. Means such that the chip-shaped member 20B can be moved by loosening the 27 can be employed. Of course, means for moving the second support portion 2B using an air cylinder or the like may be employed.
[0029]
According to such a configuration, a plurality of types of wafers W1 and W2 having different diameters D1 and D2 can be used by changing the position of the second support 2B. As described above, in the present invention, the second support portion may be provided movably. Of course, the first support portion may be movably provided.
[0030]
The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the workpiece holding mechanism according to the present invention can be variously changed in design.
[0031]
In the present invention, the specific inclination angles of the upper surfaces of the first and second support portions are not limited. In short, it is only necessary that the upper surface of the second support portion has a larger inclination angle than the upper surface of the first support portion. In addition, if the first and second support portions are provided at a plurality of locations in a narrow shape, stable support of the work piece is possible while reducing the contact area with the work piece, thereby preventing contamination. However, the present invention is not limited to this. In the present invention, each of the first and second support portions may be formed in an arc shape having a relatively long dimension, and may be provided one by one. Since the stopper surface of the second support portion is different from the stopper surface of the first support portion and is not used for clamping the work piece, it is an essential condition to provide the stopper surface on the second support portion. Absent. The first and second support portions need not be formed using a chip-shaped member, and may be formed integrally with a member such as the base plate 1 of the above embodiment.
[0032]
The work piece in the present invention is not limited to a semiconductor wafer. In the present invention, for example, a glass plate or the like can also be used. Further, the shape of the workpiece is not limited to a circular shape. For example, even in the case of a rectangular workpiece, the first and second support portions are arranged in a corresponding manner, so that the fixed and held shape is maintained. It is possible to plan. The work piece holding mechanism according to the present invention is most suitable for use as a handling device for the distal end of a robot arm, but its specific use is not limited. For example, it can be used as an alignment device for positioning a workpiece when performing a desired process on the workpiece.
[Brief description of the drawings]
FIG. 1 is a plan view showing an example of a workpiece holding mechanism according to the present invention.
FIG. 2 is a sectional view of a main part of the workpiece holding mechanism shown in FIG. 1;
3A is a plan view showing another example of the workpiece holding mechanism according to the present invention, and FIG. 3B is a sectional view of a main part thereof.
FIG. 4 is a plan view showing an example of a conventional technique.
[Explanation of symbols]
A Workpiece holding mechanism W Wafer (workpiece)
DESCRIPTION OF SYMBOLS 1 Base plate 2A 1st support part 2B 2nd support part 3 Pushing body 20A, 20B Chip-shaped member 22A, 22B Upper surface 23A, 23B Stopper surface

Claims (5)

A first support portion having an upper surface on which a part of the outer peripheral edge of the workpiece is placed, and a stopper surface rising above the upper surface;
A second support portion provided at a distance from the first support portion and having an upper surface on which another part of the outer peripheral edge of the workpiece is placed;
The work piece can be pushed from the second support portion side to the first support portion side on the upper surfaces of the first and second support portions, and can be pressed against a stopper wall of the first support portion. Pushing means for clamping the workpiece by contacting a part of the outer peripheral surface of the workpiece,
A workpiece holding mechanism comprising:
The upper surface of each of the first and second support portions is an inclined surface whose height decreases toward the center between the first and second support portions, and
A workpiece holding mechanism, wherein the inclination angle of the upper surface of the second support portion is larger than the inclination angle of the upper surface of the first support portion. The workpiece holding mechanism according to claim 1, wherein the first and second support portions are provided in a plural number. The work piece is a disc shape or a disc shape having a notch in the outer peripheral edge, and a surface of the pushing means that contacts the outer peripheral edge of the workpiece is a flat surface, a convex curved surface, or 3. The workpiece holding mechanism according to claim 1, wherein the workpiece holding mechanism has a concave curved surface having a larger radius of curvature than an outer peripheral surface of the workpiece. The workpiece holding mechanism according to claim 3, wherein the stopper surface of the first support portion is a flat surface, a convex curved surface, or a concave curved surface having a larger radius of curvature than the outer peripheral surface of the workpiece. . The workpiece holding mechanism according to any one of claims 1 to 4, wherein at least one of the first and second support portions is changeable in position so that a distance between the first and second support portions can be changed.

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