JPH01173631A - Orienting device for wafer - Google Patents

Abstract

PURPOSE:To simplify a structure and make operation reliable, by moving a rotatable roller which is deviated from a vertical line passing through the center of a wafer selectively to: a position of contact with the periphery of the wafer; a position of pushing-up of the wafer; and a rest position that is away by a short distance from the wafer downward. CONSTITUTION:A rotatable roller 3 having a rotation center axis A which is deviated from a vertical line V passing through the center of a wafer 1 housed in a cassette 20 and is separated by distance D is available. In order to move the above roller 3 selectively to: a position of contact with the periphery of the wafer 1; a position of pushing-up of the wafer upward from the above position of contact with the periphery of the wafer; and a rest position that is away by a short distance from the wafer 1 downward, an elevating mechanism 8 is installed. In this way, the simplification of a structure and the reliability of an operation are improved.

Description

[Detailed description of the invention] LL-Tachi” top! The present invention relates to a device for aligning the orientation of wafers housed in a carrier cassette (hereinafter referred to as "cassette"), and in particular, after a wafer provided with an orientation flat is placed in the cassette, the orientation or flat is adjusted upward. This invention relates to an apparatus for aligning the orientation of wafers by aligning the orientation of wafers.

1. Referring to Figures 2, 3 and 4, the cassette 20
A pocket 21 is formed on the opposing side wall of the wafer 1, and the wafer 1 is inserted into the opposing pocket 21. In order to support the lower part of the wafer 1, a supporting protrusion 2 is provided at the lower end of each pocket 21.
2 is provided, and the bottom of the cassette 20 is narrowed.

A typical cassette 20 holds about 25 wafers 1. When processing the wafers 1 while still in the cassettes 20, it may be desirable to align all the wafers l in each cassette. To facilitate this alignment, a part of the wafer 1 is cut out to provide an orientation flat 2 (FIG. 7).

A conventional device for aligning the orientation control flat 2 is a system in which a pair of rollers are rotated while contacting the periphery of the wafer l;
It is described in the 00140 publication.

The method using two rollers not only complicates the structure of the device, but also has the disadvantage that when the corner portion of the orientation flat 2 falls between the two rollers, it becomes difficult to align the orientation.

Accordingly, the problem to be solved by the present invention is to simplify the structure of the wafer orientation device and improve the reliability of its operation. To provide a wafer orientation alignment device that can reliably align the orientation of wafers.

In order to achieve the above object, the wafer orientation device according to the present invention has a wafer alignment device that is oriented so that the wafers 1 are offset from the vertical line V passing through the center C of the wafer 1 placed in the cassette 20, as shown in FIGS. 1 and 5. A rotating roller 3 having a center axis of rotation A spaced apart by a distance is used, and the rotating roller 3 is placed at a contact position with the periphery of the wafer 1 (FIG. 6), at a wafer push-up position above the contact position (FIG. 7), and A lifting mechanism 8 is provided for selectively moving the wafer 1 downwardly away from it to a resting position (FIG. 5).

The operation will be explained using a New Year illustrated example. The orientation of the wafer 1 immediately after being inserted into the pocket 21 of the cassette 20 is not constant at the position t*-1 of the flat 2, and may vary, for example, at the solid line position, dotted line position, and double-dashed line position in FIG. be. After the rotating roller 3 is raised from the rest position shown in FIG. 5 to the wafer periphery contact position shown in FIG. As long as the wafer 1 is in contact with the periphery of
Rotate in the direction of.

When the wafer 1 rotates and its orientated flat 2 comes to face the rotating roller 3, the wafer 1
A gap G is created between the wafer 1 and the rotating roller 3, and the rotation of the wafer 1 is stopped. Figure 6 shows I! fil! This shows the state where G occurs. When a large number of wafers 1 are in contact with the rotating roller 3, even if the rotation of some of the wafers 1 stops due to the generation of the gap G, the other wafers 1 in contact with the rotating roller 3 continue to rotate. , all the wafers l come to a halt due to the generation of the gap G.

When the orientation number flat 2 is facing downward as shown by the broken line in FIG. 5 from the beginning, the above-mentioned gap G may already exist when the rotating roller 3 rises to the contact position shown in FIG. 6. Therefore, due to the generation of the gap G, the orientation of the orientation flat 2 when all the wafers 1 are stopped has some irregularity, as shown by the solid line and broken line in FIG. 6.

When the rotating roller 3 is raised from the contact position shown in FIG. 6 to the wafer pushing position shown in FIG.
Since there is the above-mentioned deviation D, the wafer 1 is placed on the rotating roller 3.
It is separated from the support protrusion 22 on the other side, that is, the right side in FIG. 7, is supported by the support protrusion 22 on the other side, that is, the left side in FIG. do. The present inventor experimentally determined that the orientation flats 2 of a large number of wafers 1, which were at irregular stop positions as shown in FIG. 6, align at a constant inclination when pushed up as shown in FIG. I found it.

Next, if the rotating roller 3 is rotated by a required angle corresponding to approximately half a rotation of the wafer 1 in a counterclockwise direction, that is, in the direction of arrow R1 in FIG. The orientation flat 2 rotates clockwise, ie in the direction of arrow R2 in FIG. 8, to the upward position of FIG. In this way, the orientations of all the wafers l in the cassette 20 are reliably aligned, and the objective of ensuring alignment of wafer orientations according to the present invention is achieved.

If necessary, if the rotating roller 3 is lowered as shown by the arrow in FIG. 8, all the wafers 1 are supported on the support protrusion 22 with the orientation flats 2 facing upward. Ru.

In the embodiment shown in FIG. 1, the rotating roller 3 is mounted on a bearing (not shown).
etc., and a pulley 5 is attached to one end of the rotating shaft.
is installed. The frame body 4 holds a drive motor 6, and a drive belt 7 engages with the drive motor 6 and pulley 5 to transmit drive rotational force to the rotating roller 3. A lifting mechanism 8 raises the frame 4 to which the rotating roller 3 and its driving device are attached toward the cassette 20 and lowers it from the cassette 20.

The lifting mechanism 8 can be a conventional hydraulic device, such as hydraulic or pneumatic.

The operation of this embodiment is as already explained.

As explained in detail above, the wafer orientation device according to the present invention moves the rotating roller offset from the vertical line passing through the center of the wafer to the contact position with the periphery of the wafer, the wafer push-up position, and the position away from the wafer. Since it selectively moves downward to a resting position, the following effects are achieved.

(a) The structure is simpler than the conventional device using two rotating rollers, and the number of parts and cost can be reduced.

(b) Since the orientation is aligned by a single rotating roller, the corner of the orientation flat will not fall between the two rotating rollers, ensuring reliable operation.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a wafer orientation device according to the present invention, FIG. 2 is a plan view of a wafer holding cassette, FIGS. 3 and 4 are sectional views of essential parts of the cassette, and FIGS. 6
, FIG. 7, and FIG. 8 are operation explanatory diagrams. 1... Wafer, 2... Orientation flat, 3... Rotating roller, 4... Frame,
5... Pulley, 6... Drive motor, 7... Drive belt, 8... Lifting mechanism, 20... Cassette, 21... Pocket, 22... Support protrusion,
A... Rotation center axis, C... Center of wafer 1, ■... Vertical line passing through C, D... Offset from V. Patent applicant Okura Electric Co., Ltd. Patent application agent Patent attorney Ichitore Tsugube U Figure 6

Claims (1)

[Claims] In a device for aligning the orientation of wafers with orientation flats in a cassette, there is a rotating roller having a rotation center axis that is offset from a vertical line passing through the center of the wafer, and the rotating roller is placed at a contact position with the periphery of the wafer, or from the contact position. A wafer orientation device comprising a raising and lowering mechanism that selectively moves the wafer to a high wafer push-up position and to a rest position downwardly away from the wafer.