JPS6323654B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a wafer positioning device for positioning a wafer (semiconductor slice) in a predetermined direction before supplying the wafer (semiconductor slice) to a photolithography process, circuit inspection process, etc. It is something.

[Background technology] In order to supply wafers in various orientations in the same orientation (orientation) to a photolithography process, circuit inspection process, etc., a portion of the periphery of the wafer is cut out to provide a straight part (orientation flat), and this straight part It is normal to position the wafer based on the . By the way, some conventional positioning devices place the wafer on a smooth flat surface coated with Teflon and rotate the wafer on this flat surface to position it in a predetermined direction. However, during rotation, the coefficient of friction was still large, making it impossible to rotate the wafer smoothly. There was also a structure in which the wafer was rotated while being floated with pressurized air, but it was extremely difficult to uniformly blow out the air from a nozzle, etc., and accurate positioning was also difficult in this case. Further, when a nozzle and the like are provided, the entire device becomes extremely large-scale and expensive.

[Object of the Invention] An object of the present invention is to provide a wafer positioning device that has a simple structure and is capable of smoothly rotating a wafer and positioning it in a predetermined posture (orientation).

[Structure of the Invention] Therefore, the present invention provides rotation in which the wafer is supported in an inclined state from the back side of the wafer at three support points, and the wafer is rotated within the plane by frictionally contacting the lower peripheral edge of the inclined wafer. A drive mechanism is provided, and two of the three support points are arranged on substantially the same virtual circumference with the center point of the rotation center of the wafer and at a predetermined interval above the center point. On the other hand, the remaining one support point is placed below the center point, avoiding the virtual perpendicular bisector of the two support points, and the three support points arranged in this way slightly hold the wafer. By rotating the wafer by the rotary drive mechanism while supporting it in an unstable state, the coefficient of friction between the wafer and each support point is made extremely small, and the wafer and the rotary drive mechanism are made to fit well together. The purpose is to achieve the above objective by realizing smooth rotation.

[Description of Examples] Examples of the present invention will be described below based on the drawings.

An embodiment of the wafer positioning device according to the present invention is shown in FIGS. 1 and 2, and in these figures,
The base 11 is configured to be tiltable from a horizontal direction to a tilted state at a predetermined angle, for example, with a support portion 12 provided on the back side of the base 11 as a center of tilting. On the upper surface of this base 11, two guide rails 13 are provided.
These two guide rails 13 are arranged parallel to each other at a predetermined interval along the vertical direction in the figure, and a straight straight portion 14 is formed by cutting out a part of the circumferential surface between these two guide rails 13. A thin disc-shaped wafer 15 is guided as shown in FIG.

Further, on the upper surface of the base 11, there are first, second, and third support points 16, 1 for supporting the wafer 15 guided between the two guide rails 13 from the wafer back side.
7 and 18 are provided protrudingly. These support points 16,
The tops of the supporting points 16, 17, 18 are, for example, spherical and polished with high precision.
The coefficient of friction between the wafer 18 and the wafer 15 is extremely small.

The wafer 15 is rotated by a rotation drive mechanism 21 provided below the wafer 15, and the first and second support points 16 and 17 are connected to the wafer 15, respectively.
The same virtual circumference S with the rotation center C of 5 as the center point
They are arranged above the rotation center C and spaced apart from each other by a predetermined distance. on the other hand,
The third support point 18, which is the remaining one support point, is located below the rotation center C and away from the virtual perpendicular bisector T of the first and second support points 16 and 17. It is located. More specifically, the first and second support points 16 and 17 are arranged at an interval of 120 degrees on the circumference, and the perpendicular bisector T of these support points 16 and 17 passes through the center point C. Guide rail 1
It is parallel to 3. Also, the third support point 18
is located at a position shifted by x from the perpendicular bisector T.

The rotational drive mechanism 21 includes two drive rollers 22.
These drive rollers 22 are respectively connected to pulleys 23 on the lower side of the base 11, and the pulleys 23 and drive pulleys 24 are interlocked with each other by a belt 25, and the drive pulley 24 is rotated by a drive motor 26. The two drive rollers 22 are adapted to be rotated. These two drive rollers 22
are arranged along the horizontal direction at equal distances apart from each other on both sides of the virtual vertical bisector T, in other words, they are arranged to form the vertical bisector T of both drive rollers 22. There is. The lower peripheral edge of the inclined wafer 15 comes into frictional contact with the two drive rollers 22, thereby causing the wafer 15 to rotate in a predetermined direction within its plane.

A guide roller 31 is rotatably supported on the outside of the two drive rollers 22, respectively. As shown in FIG. 1, these guide rollers 31 have a predetermined gap between them and the periphery of the wafer 15 when the wafer 15 is rotated in frictional contact with the two drive rollers 22. Although the arrangement is such that a gap is provided, the rotation of the wafer 15 by the drive roller 22 progresses, and as shown in FIG. When the wafer 15 is moved downward by a predetermined amount, the arcuate outer circumferential portion of the wafer 15 comes into contact with both guide rollers 31 and supports the lower circumferential edge of the wafer 15. A predetermined gap is provided between them, and the rotation of the wafer 15 is stopped, that is, the wafer 15 is positioned at this position.

Next, the operation of this embodiment will be explained. With the base 11 in a horizontal state, the wafer 15 is transferred to the support point 1 on the base 11 using a transfer device (not shown).
6, 17, and 18 in any direction, and then the base 11 is tilted at a predetermined angle with the support portion 12 as the tilting center (see FIG. 2). As a result, the wafer 15, as shown in FIG.
The lower peripheral surfaces of the two drive rollers 22 of the rotational drive mechanism 21 come into contact with each other. When the drive roller 22 is rotated with the drive roller 22 in frictional contact with the lower peripheral surface of the wafer 15 in this way,
The wafer 15 is rotated within its plane around the rotation center C, and as the rotation progresses and the straight portion 14 of the wafer 15 is placed on the drive roller 22 as shown in FIG. , wafer 15
The lower peripheral edge is supported by a guide roller 31 instead of the drive roller 22, and the drive roller 22 is separated from the straight portion 14, and the rotation of the wafer 15 by the rotary drive mechanism 21 stops, and in this stopped state, the wafer 15 will be positioned on the base 11. Thereafter, it is accurately transferred to a photo-etching process, a circuit inspection process, etc. (not shown) using a sophisticated handling mechanism or the like.

According to this embodiment, three support points 1
6, 17, and 18 to support the wafer 15 from the back side of the wafer, these support points 1
There is an effect that the frictional resistance between the wafer 15 and the wafer 15 is extremely small, and the wafer 15 can be rotated extremely smoothly.

Moreover, the first and second support points 16 and 17 are arranged on the same circumference S at a predetermined interval, while the third
By arranging the supporting point 18 of the first and second supporting points 16, 17 while avoiding the virtual perpendicular bisector T, the wafer supported on these three supporting points 16, 17, 18 can be Although the wafer 15 is supported stably as a whole, it is supported in a moderately unstable state, and by adding this moderate instability, the wafer 15 can be rotated smoothly. There is an effect that it can be done. Furthermore, by supporting the wafer 15 in such an unstable state, the lower peripheral edge of the wafer 15 and the drive roller 22 of the rotational drive mechanism 21 become more compatible, and the relationship between the peripheral edge and the drive roller 22 improves. There is no slippage or idle rotation, and from this point of view as well, the wafer 15 can be rotated extremely smoothly and positioned at a predetermined position (orientation).

Furthermore, the three supporting points 16, 17, 18 have an extremely simple structure, for example, they can be made of hard balls, etc., and the arrangement positions of the supporting points 16, 17, 18 having such a simple structure are Since it is intended to achieve smooth rotation of the wafer 15 by devising a device, the structure is extremely simple, unlike a conventional structure having an air blowing device or the like.

Furthermore, the wafer 15 is rotated by the rotary drive mechanism 21 and the straight portion 14 is rotated by the drive roller 22.
Since the wafer 15 leaves the drive roller 22 when it comes to the top, it is automatically stopped and positioned, and there is no need for any special position inspection device or stop device to stop the rotation of the wafer 15 or any operation thereof. From this point of view as well, the structure is extremely simple and the positioning operation is easy.

In addition, in implementation, the base 11 does not necessarily have to be tiltable, and may be fixed in a predetermined tilted state. Moreover, although the rotational drive mechanism 21 has two drive rollers 22, it may have one or three or more drive rollers 22. However, according to the embodiment in which the two drive rollers 22 are arranged horizontally at a predetermined interval, smooth rotation can be achieved during rotation, and in combination with the two guide rollers 31, the notch 15 of the wafer 15 can be rotated smoothly. There is an advantage that when the roller 22 reaches the drive roller 22, it can be automatically stopped as described above. Furthermore, the distance between the first and second support points 16 and 17 is not limited to 120 degrees, but may be any other distance, and may not be equally spaced on both sides of the bisector T. Furthermore, the third support point 18 may or may not be on the virtual circumference S.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a wafer positioning device that has a simple structure and is capable of smoothly rotating a wafer and positioning it at a predetermined position (orientation).

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of a wafer positioning device according to the present invention, and FIG.
FIG. 3 is a sectional view taken along the line and a front view showing the positioning state of the wafer in the embodiment. 11... Base, 13... Guide rail, 14...
Straight line part, 15... Wafer, 16, 17, 18...
Support point, 21... Rotation drive mechanism, 22... Drive roller, 31... Guide roller.

Claims (1)

[Claims] 1. Three support points that support the wafer in an inclined state from the back side of the wafer, and a rotation drive mechanism that rotates the wafer within the plane by frictionally contacting the lower peripheral edge of the inclined wafer, Two of the two support points are arranged on substantially the same virtual circumference with the center of rotation of the wafer as the center point, and are spaced apart from each other by a predetermined distance above the center point. A wafer positioning device characterized in that the support point is disposed below the center point, avoiding a virtual perpendicular bisector of the two support points.