JP4339615B2 - Workpiece holding mechanism - Google Patents

Description

[0001]
BACKGROUND 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]
Conventionally, as an example of this type of workpiece holding mechanism, there is one described in Patent Document 1. As shown in FIG. 4, this conventional holding mechanism includes a plurality of support portions 91 provided on the upper surface of the base plate 90 and a workpiece W placed on the plurality of support portions 91 at the edge of the tip of the base plate 90. And 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]
Japanese Patent Laid-Open No. 2000-308988
[Problems to be solved by the invention]
When handling the workpiece W, it should be sufficient not to cause dirt or scratches on the front and back surfaces of the workpiece W, or to generate dust such as chipping powder due to the semiconductor wafer being shaved. You may have to consider. In particular, when the workpiece W is a wafer used for manufacturing a semiconductor device, more careful handling is required.
[0005]
However, in the above prior art, when the workpiece W is pushed by the pair of pushing members 92, the back surface of the workpiece W is rubbed 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 scraped powder is generated. Patent Document 1 also describes a technique for reducing the contact frictional force between the workpiece W and the support portion 91 by using a rotatable ball member as the support portion 91, but with such means, The cost of parts becomes high, resulting in a cost disadvantage. In addition, the burden of maintenance 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 clamp by means of a simple structure while minimizing the possibility of damage to the workpiece as much as possible. The challenge is to be able to do it.
[0007]
DISCLOSURE OF THE INVENTION
In order to solve the above problems, the present invention takes the following technical means.
[0008]
The workpiece holding mechanism provided by the present invention includes an upper surface on which a part of the outer peripheral edge of the workpiece is placed, a first support portion having a stopper surface rising above the upper surface, and the first support portion. A second support portion provided in a region opposite to the support portion with the center of the workpiece interposed therebetween , and having an upper surface on which another part of the outer peripheral edge of the workpiece is placed; and the workpiece The outer peripheral edge can be pushed toward the first support part while contacting a part of the outer periphery of the first support part with the upper surface of the first and second support parts, and on the stopper surface of the first support part. And a pressing means for clamping the workpiece in cooperation with the stopper surface of the first support portion by contacting a part of the outer peripheral surface of the workpiece. Holding mechanism And each upper surface of the said 1st and 2nd support part is made into the inclined surface where height becomes low near the center part between the said 1st and 2nd support part, and said 1st The inclination angle of the upper surface of the second support portion is made larger than the inclination angle of the upper surface of the support portion .
[0009]
According to such a structure, in the state which mounted the workpiece on the upper surface of the 1st and 2nd support part so that a part of outer periphery might contact, a 2nd support part by a pushing means When the workpiece is pushed from the side to the first support portion side, the workpiece is clamped between the pushing means and the stopper surface of the first support portion and is appropriately fixed and held. Since the upper surfaces of the first and second support portions are both inclined surfaces, when the workpiece is placed on these upper surfaces, these upper surfaces 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 is slid on the upper surface by being pushed by the pushing means. Accordingly, the contact area between the workpiece and the first and second support portions is made extremely small, and no member contact with the portion other than the outer peripheral edge of the workpiece is caused, so that the workpiece is not stained or scratched. It is possible to properly fix and hold them without connecting them.
[0010]
Furthermore, 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 the first and second support portions. When the upper surface of the first support portion is slid from the second support portion side to the first support portion side, the resistance of the upper surface of the first support portion with respect to the sliding operation can be reduced. On the other hand, since the inclination angle of the upper surface of the second support part is relatively large, an action of promoting the movement of the workpiece sliding toward the first support part is obtained. By such a thing, in this invention, the operation | movement when a workpiece slides on the 1st and 2nd support part can be smoothed, and generation | occurrence | production of the abrasion powder by friction, etc. can be suppressed appropriately. . In the present invention, the upper surfaces of the first and second support portions may be formed as simple inclined surfaces. Unlike the means for rotatably providing the ball member of Patent Document 1, the first and second support portions are provided. Since it is not necessary to provide the whole or a part of the part operably, the manufacture thereof 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 workpiece can be reduced, and the possibility that the workpiece is scratched or rubbed powder is generated can be reduced.
[0012]
In a preferred embodiment of the present invention, the workpiece is disk-shaped or disk-shaped having a notch on the outer peripheral edge, and the surface of the pushing means that 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 structure, the said pressing means and the outer peripheral surface of the said workpiece can be made into a point contact or the contact state close | similar to it, and those contact areas can be made small. Therefore, it is suitable for reducing the possibility of scratches on the workpiece.
[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 as a point contact or a contact state close thereto, so that the contact area is reduced and the workpiece is damaged. It can be prevented more thoroughly.
[0014]
In a preferred embodiment of the present invention, at least one of the first and second support portions is capable of changing the position so that the distance between them can be changed. According to such a configuration, it is possible to support and fix and hold a plurality of types of workpieces having different outer diameters by adjusting the position of at least one of the first and second support portions.
[0015]
Other features and advantages of the present invention will become more apparent from the following description of embodiments of the invention.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment 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 300 mm, for example. As shown well in FIG. The second support portions 2A and 2B and a pair of pushers 3 are provided. A notch (orientation flat) is formed on the outer peripheral edge of the wafer W, but it is omitted in the drawing.
[0018]
The base plate 1 is formed of a plate material made of carbon fiber reinforced plastic, for example, and a robot arm 8 is attached to a base end portion (right side portion in FIG. 1). As this robot, for example, a multi-axis / multi-joint type that can move the arm 8 in the three-dimensional x, y, and z-axis directions is used, but it is not limited to this. The holding mechanism A of the present embodiment plays a role as a handling mechanism unit of the robot. The base plate 1 has a vertical width smaller than the diameter of the wafer W in order to reduce the weight and the like, and a region near the tip of the base plate 1 is bifurcated.
[0019]
The first and second support portions 2A and 2B are provided by attaching chip-like members 20A and 20B separate from the base plate 1 to the base plate 1 using bolts 21 or the like. The material of the chip-like members 20A and 20B is, for example, PEEK (polyether ether ketone) as having high mechanical strength such as impact resistance and excellent fatigue resistance and environmental resistance. Yes. The pair of first support portions 2 </ b> A are provided on the two distal ends of the base plate 1, and the pair of second support portions 2 </ b> B 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 so as to be able to support four locations on the outer peripheral edge of the wafer W. Moreover, those arrangements are 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 for placing the outer peripheral edge of the wafer W, and stopper surfaces 23A and 23B rising from the upper surfaces 22A and 22B. As clearly shown in FIG. 2, the upper surfaces 22 </ b> A and 22 </ b> B are both planar inclined surfaces whose height decreases toward the central portion of the base plate 1. 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 dropping off from these portions, and have appropriate heights. These stopper surfaces 23 </ b> A and 23 </ b> B are flat surfaces, convex curved surfaces, or concave curved surfaces having a radius of curvature larger than the outer peripheral surface of the wafer W, and can make point contact with the outer peripheral edge of the wafer W. (However, the contact state in a plan view is a point contact, and in the thickness direction of the wafer W, the contact point is a line contact state extending).
[0021]
The pair of pushers 3 are for pushing the wafer W, are located in the vicinity of the second support portion 2B, and are provided in a symmetrical arrangement with the center line L in between. The pusher 3 is attached to a reciprocating rod 31a of an air cylinder 31 provided in a region near the base end portion of the base plate 1 and can reciprocate in the direction of arrow N1 (direction in which the center line L extends). Of the pusher 3, the front end surface 30 for contacting the wafer W is also a flat surface, a convex curved surface, or a concave shape having a larger curvature radius than the outer peripheral surface of the wafer W, similarly to the stopper surfaces 23 </ b> A and 23 </ b> B described above. 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 configured as described above 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 these upper surfaces 22A and 22B are inclined surfaces, The outer peripheral edge of the wafer W and these upper surfaces 22A and 22B are in a point contact state. Usually, the outer peripheral edge of the wafer W is rounded, but even when such roundness is given, contact with the inclined upper surfaces 22A and 22B is point contact. Become. Therefore, the contact area of the first and second support portions 2A and 2B to the back surface of the wafer W can be reduced, and the wafer W can be prevented from being contaminated.
[0024]
Next, the pair of pushers 3 are advanced toward the first support portion 2A. As a result, the wafer W is pushed and the two outer peripheral edges abut against the stopper surfaces 23A of the pair of first support portions 2A, and the wafer W is clamped by the stopper surfaces 23A and the pair of pushers 3. Will be held. If the wafer W is held in this way, the robot arm 8 can be moved in various directions to transfer the wafer W to a desired position. If the pusher 3 is moved backward, the holding state of the wafer W is released and can be taken out from the holding mechanism A.
[0025]
When the wafer W is pushed by the pusher 3, the wafer W slides on the upper surfaces 22A and 22B of the first and second support portions 2A and 2B. However, since the inclination angle α of the upper surface 22A is small, the wafer W 2 can be reduced in resistance when the outer peripheral edge slides on the upper surface 22A toward the stopper surface 23A in the direction of the arrow N2 in FIG. On the other hand, since the inclination angle β of the upper surface 22B is large, the outer peripheral edge of the wafer W can easily slide on the upper surface 22B in the direction of the arrow N2. Therefore, a large frictional force is not generated between the outer peripheral edge of the wafer W and the upper surfaces 22A and 22B, and generation of dust such as shaving powder is suppressed. Even while the outer peripheral edge of the wafer W slides on the upper surfaces 22A and 22B, they maintain a point contact state, so that no scratches or the like occur near the outer peripheral edge of the wafer W. . The pusher 3 pushes the outer peripheral surface of the wafer W in a planar viewpoint contact state, and when the wafer W is clamped, the tip surface 30 of the pusher 3 and the stopper surface of the first support portion 2A. 23A is also in a planar viewpoint contact state with the outer peripheral surface of the wafer W, so that the pusher 3 and the stopper surface 23A contaminate the outer peripheral surface of the wafer W or damage parts other than the outer peripheral surface. This is also suppressed appropriately.
[0026]
As described above, according to the holding mechanism A of the present embodiment, the wafer W can be fixed and held such that the constituent members of the holding mechanism A do not touch any part other than the outer peripheral edge or the outer peripheral surface of the wafer W. It is possible to appropriately prevent the wafer W from being scratched or soiled. The first and second support portions 2A and 2B are merely configured by attaching the chip-like members 20A and 20B to the base plate 1, and for example, means for rotatably mounting the ball member described in Patent Document 1 The cost is low and the maintenance is easy. Further, since the pair of pushers 3 and the two stopper surfaces 23A are symmetrical with respect to the center line L, when the pusher 3 is advanced and the wafer W is clamped, the center of the wafer W is set to the two stopper surfaces 23A. Thus, a so-called centering function that is adjusted to a predetermined position with reference to is also suitably obtained.
[0027]
FIG. 3 shows another embodiment of the present invention. In the figure, the same or similar elements as those of the above embodiment are denoted by the same reference numerals as those of the above embodiment.
[0028]
In the embodiment shown in FIG. 3, the number of second support portions 2B is one, and the position of this second support portion 2B is adjustable in the direction of arrow N3. As a means for that purpose, for example, a hole 28 into which a bolt 29 for fixing a chip-like member 20B constituting the second support portion 2B is inserted is formed in a long hole, and a tightening nut screwed into the bolt 29 is formed. It is possible to adopt means such that the chip-like member 20B can be moved by loosening 27. Of course, a means for moving the second support portion 2B using an air cylinder or the like may be employed.
[0029]
According to such a configuration, by changing the position of the second support portion 2B, it is possible to use a plurality of types of wafers W1 and W2 having different diameters D1 and D2 as usage targets. Thus, in this invention, you may provide a 2nd support part so that a movement is possible. Of course, the first support portion may be provided so as to be movable.
[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 varied in design in various ways.
[0031]
In the present invention, the specific inclination angle of the upper surfaces of the first and second support portions is not limited. In short, it is only necessary that the upper surface of the second support part has a larger inclination angle than the upper surface of the first support part. In addition, if the first and second support portions are provided in a plurality of narrow shapes, the contact area with the workpiece can be reduced and stable support of the workpiece can be achieved. Although it is preferable from the viewpoint of the above, it is not limited to this. In this invention, it can also be set as the structure which formed each of the 1st and 2nd support part in the arc shape of a comparatively long dimension, and provided one each. Since the stopper surface of the second support portion is not used for clamping the workpiece, unlike the stopper surface of the first support portion, it is necessary to provide a stopper surface on the second support portion. Absent. The 1st and 2nd support part does not need to be comprised using the chip-shaped member, for example, can also be integrally formed in members like the base plate 1 of the said embodiment.
[0032]
The workpiece referred to in the present invention is not limited to a semiconductor wafer. In this invention, a glass plate etc. can also be made into object, for example. Further, the shape of the workpiece is not limited to a circular shape. For example, even if the workpiece is a rectangular shape, the first and second support portions are arranged corresponding to the workpiece, thereby fixing and holding the workpiece. It is possible to plan. The workpiece holding mechanism according to the present invention is optimal for use as a handling device for the tip of a robot arm, but its specific use is not limited. For example, it can also be used as an alignment device for positioning the workpiece when a desired process is performed 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 cross-sectional view of a main part of the workpiece holding mechanism shown in FIG. 1;
FIG. 3A is a plan view showing another example of a workpiece holding mechanism according to the present invention, and FIG.
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 (11)

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 in a region opposite to the first support portion across the center of the workpiece and having an upper surface on which another part of the outer peripheral edge of the workpiece is placed;
The workpiece can be pushed toward the first support portion while a part of the outer peripheral edge thereof is in contact with the upper surfaces of the first and second support portions, respectively, and the first support portion A pressing means for clamping the workpiece in cooperation with the stopper surface of the first support portion by bringing a part of the outer peripheral surface of the workpiece into contact with the stopper surface of
A workpiece holding mechanism comprising:
Each upper surface 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 an inclination angle of an upper surface of the second support portion is made larger than an inclination angle of an upper surface of the first support portion. The workpiece holding mechanism according to claim 1, wherein a plurality of the first support portions are provided, and at least one second support portion is provided. It said first and second support portions are provided with a plurality each holding mechanism of a workpiece according to claim 1. The workpiece is disk-shaped or disk-shaped having a notch at the outer periphery, and the surface of the pushing means that contacts the outer periphery of the workpiece is a flat surface, a convex curved surface, or the surface than the outer peripheral surface of the workpiece there is a large concave curved surface of curvature radius, the holding mechanism of a workpiece according to any one of claims 1 to 3. The workpiece holding mechanism according to claim 4 , wherein the stopper surface of the first support portion is a flat surface, a convex curved surface, or a concave curved surface having a radius of curvature larger than that of the outer peripheral surface of the workpiece. . The workpiece holding mechanism according to claim 1, wherein one each of the first and second support portions is provided. The workpiece holding mechanism according to claim 6 , wherein the first and second support portions are formed in an arc shape. The workpiece holding mechanism according to any one of claims 1 to 7 , wherein at least one of the first and second support portions is capable of changing a position so that a distance between them can be changed. Comprising a base plate, said first and second supports are either formed on the base plate, or attached to the base plate, the holding mechanism of a workpiece according to any one of claims 1 to 8 . The workpiece according to claim 9 , wherein the first support portion is attached to a region near the tip end portion of the base plate, and the second support portion is attached to a region near the base end portion of the base plate. A piece holding mechanism. 11. The workpiece holding mechanism according to claim 10 , wherein the first and second support portions are arranged symmetrically with respect to a center line passing through a base end portion and a tip end portion of the base plate.

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