JPS63241948A - Wafer transfer device - Google Patents

Abstract

PURPOSE:To simply position a wafer while the wafer is placed on an arm and to effectively position the wafers individually by forming the abutting part of the arm in a circular arc shape along the circumferential side face of the wafer, and forming the chordal end of the circular arc wider than that of an orientation flat part. CONSTITUTION:The abutting part of an arm 3 is formed in a circular arc shape along the circumference of a wafer 2, and a roller 22 is so disposed as to abut on the wafer 2 at a position wider than the shortest distance of the other end of an orientation flat part to the center line of the circular arc when one end of the orientation flat part is aligned with the circular arc end from the center line of the circular arc at least at both sides to abut on the wafer 2 with the circular arc. When the arm 3 is pressed forward to press the wafer 2 to the abutting part 4 of the arm 3, the wafer 2 is positioned at a predetermined position by the centering action of the roller 22 and the contacting part 4 of the arm even if the orientation flat part is disposed at any position, and then placed on the waver to be transfer. Thus, the wafers are positioned on the arm effectively one by one.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wafer transport device, and particularly to a wafer transport device suitable for cleanly transporting wafers.

[Conventional technology]

Conventional equipment has been used, for example, as shown in FIG. Some wafers are unloaded by an arm, and care is taken to avoid particle generation.

[Problem that the invention seeks to solve]

The above conventional technology does not take into account the positioning of the wafer on the arm when placing the wafer on the arm from within the cassette, and therefore it is necessary to accurately determine the position of the wafer within the cassette in advance. be. therefore,
If the orientation flats of the wafers stored in the cassette are in different directions.

Since the wafer storage position within the cassette shifts and the wafer ends become uneven, such an apparatus usually aligns the orientation flat within the cassette to align the wafer storage position. In this process, the wafer is rotated with the wafer stored in the cassette, so particles may be generated due to friction with the wafer storage groove and adhere to the wafer, or the particles generated may adhere to the roller that rotates the wafer. There is a problem in that this adheres roughly to the wafer, reducing the yield of wafers.

An object of the present invention is to easily perform positioning while placing the wafer on an arm without performing positioning by aligning the orientation flat, thereby reliably positioning each wafer and suppressing the generation of particles. ,
It is an object of the present invention to provide a wafer transfer device that can carry out highly reliable and clean transfer.

The above purpose is to provide a wafer contact portion at the end of the wafer placement surface on the base side of the arm in a wafer transfer device that places and transports the wafer on an arm, and to place the wafer on the arm. The arm is equipped with at least two or more rollers that press the wafer against the contact part from the tip side, and the contact part is shaped like an arc along the circumferential side of the arm, and the chord end of the arc is at least wider than the width of the orientation flat. The wafer is arranged so that the wafer can be positioned by the mutual alignment between the contact part and the roller, that is, the contact point between the roller and the wafer extends from the center line of the arc to at least one end of the orientation flat on both sides of the arc. This is achieved by arranging the rollers so that the distance is wider than the shortest distance between the other end of the orientation flat and the stop line of the arc when the wafers are aligned and brought into contact with the arc.

[For production]

The contact part of the arm is in the shape of an arc along the circumference of the wafer, and the rollers are arranged on both sides from the center line of the arc, with one end of the orientation flat aligned at least at the end of the arc, and the wafer is brought into contact with the arc part. The roller and wafer are arranged so that they touch at a point wider than the shortest distance between the other end and the center line of the arc, so the arm is pushed forward and the roller pushes out the wafer.

By pressing the wafer against the contact part of the arm, the wafer is positioned at a predetermined position by the mutual alignment between the roller and the contact part, no matter where the orientation flat is located.
Since the wafers are then placed on top of the wafers and transported, each wafer is reliably positioned on the arm, and the wafers are less likely to shift inside the cassette, preventing particle build-up. , allows for highly reliable and clean flame propagation.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

FIG. 1 shows the overall configuration of a wafer transfer device, and in this case, a case will be described in which a wafer is transferred from a cassette containing the wafer. The cassette mounting table 6 has a housing 17
It is attached to the upper part of a shaft 18 that is guided and supported so as to be movable in the axial direction by a bearing 16 provided therein, and the cassette 1 containing the wafers 2 is placed on the upper surface.

A female threaded portion is provided at the lower part of the shaft 18, and the threaded shaft 7 driven by the motor 15 via the belt 9 and pulleys 8, 14 is engaged therewith. The pulley 8 is attached to the lower part of the screw shaft.

Three and two plates 10 and 11 are attached to the motor shaft of the motor 15 to which the pulley 14 is attached, and the slit plate 1
0.11 is equipped with sensors 12 and 13.

A wafer detection sensor 5 is provided at the upper part of the cassette table 6 and below the lowest wafer 2 in the cassette 1, and an arm that can be taken in and out by a drive device (not shown) is provided between the wafer 2 and the wafer detection sensor 5. 3, and a roller 22 is provided on the side opposite to the arm 3 of the wafer 2. In this case, the roller 22 is movably guided by the bearing 21 toward the wafer 2 side, and the air cylinder 19 is moved through the leaf spring 20.
It is connected to. The leaf spring 20 serves to absorb shock and prevent overload.

As shown in FIG. 2, the base side of the arm 3 is provided with an arcuate contact portion 4 that matches the diameter of the wafer 2, and the chord width L1 of the arc is larger than the width of the orientation flat of the wafer 2. It is. Further, in this case, wafer support members 23 made of silicone rubber are attached to the wafer mounting surface of the arm 3 at three locations to prevent slipping and to reduce the contact area with the wafer.

As shown in FIG. 2, the roller 22 is aligned with the other end of the orientation flat when the wafer is brought into contact with the arc with one end of the orientation flat aligned with at least the end of the arc on both sides from the center line of the arc of the contact portion 4. The roller 22 and the wafer 2 are arranged so that the roller 22 and the wafer 2 are in contact with each other at a distance *L3 that is wider than the shortest distance L2 from the center line, and the distance from the center line to the point of contact is L3. In this case, two rollers 22 are provided. From the viewpoint of preventing the generation of particles, the material is preferably a resin such as 42-fluorinated ethylene resin, polyacetal resin, or polyimide resin.

The operation of the apparatus configured as described above will be explained. In FIG. 1, when the motor 15 is rotated by a control device (not shown), the screw shaft 7 is turned, and the shaft 18 is moved downward, and the cassette 1 on the cassette mounting table 6 is lowered.
The wafer 2 stored at the lowest position in the cassette 1 approaches the wafer detection sensor 5.

When the wafer 2 has descended to a predetermined position, that is, a position where the arm 3 can be inserted, the wafer detection sensor 5 detects this and sends a signal to the control device to stop the motor 15.

In this position, the control device inserts the arm 3 into the cassette 1 and positions it below the wafer 2.

The relationship between the wafer 2 and the arm 3 at this time is shown in FIG. 3.As shown in FIG.
a and the wafer support member 23 of the arm 3 with a gap δ between them, and the arm 3 is inserted with the gap δ. At this time, even if the wafer 2a is shifted by one position and protrudes from inside the cassette 1, the wafer 2a is pushed into the cassette 1 by inserting the arm 3 into the cassette l.

Further, at the stage when the arm 3 is inserted, the wafer 2a and the upper wafer 2b are placed and stored in the groove in the cassette 1 with a pitch P.

In this state, as shown in FIGS. 1 and 4, the roller 22 moves toward the arm 3 via the leaf spring 20 by the contraction operation of the air cylinder 19 controlled by the control device in this case, and /\2a is pushed toward the base of the arm 3. As a result, the wafer 2a touches the contact portion 4 of the arm 3.
and is positioned relative to the arm 3. At this time, the wafer 2a is supported by the groove in the cassette l and moves.

This positioning state will be explained with reference to FIGS. 6 to 8. 6(a) to (C) show the process of pressing the wafer 2, which is housed in the cassette with a deviation from the center of the circular arc portion of the arm 3, against the contact portion 4 of the arm 3 using the roller 22. . First, as shown in (a), in this case, the roller 22b hits the wafer 2 and pushes it toward the arm 3, and then (
In this case, as shown in b), there is a sea urchin/\\ at one end of the contact part.
By further pushing the roller 22b, the wafer 2 is rotated clockwise around the point where the wafer 2 and the contact portion 4 contact each other, as shown in (C). It is stored in the connecting part 4.

For example, when the orientation flat of the wafer 2 hangs over the arcuate portion of the contact part 4 as shown in FIG. The moment F+11 and the counterclockwise moment F,lz are applied, and in this case, F,11<Fl 12, so the wafer 2 tries to rotate clockwise around the contact point 0, but in this case,
The center of wafer 2 is on the left side of the line connecting contact 0 and roller 22a (that is, if wafer 2 tries to rotate clockwise around contact 0, the center of wafer 2 is on the left side of the line connecting contact 0 and roller 22a). 22a), the clockwise rotation movement of the wafer 2 is restrained by the roller 22a and cannot be rotated. can be positioned. Note that when the orientation flat is located on the opposite side, positioning can be performed in the same way, just by reversing the relationship of force.

Further, for example, when the orientation flat of the wafer 2 is inclined toward the rollers 22a and 22b as shown in FIG. Since it acts on the contact point, even if the point of action is shifted from the center of the wafer 2, the force that presses the wafer 2 against the arcuate portion is stronger and does not reach the point of rotating the wafer 2, so the contact portion The center of the arc 4 and the center of the wafer 2 can be aligned and positioned.

Next, after the wafer 2 and the arm 3 have been positioned, the roller 22 is returned to its original position and separated from the wafer 2a, and the cassette mounting table 6 is lowered by a moving amount S, as shown in FIG. As a result, the wafer support member 2 of the arm 3
3, the weno bag 2a is placed on it. After that, arm 3
is moved to carry out the wafer 2a from the cassette 1.

Note that the movement amount S for lowering the cassette mounting table 6 is controlled as follows.

The rotation of the motor 15 shown in FIG. 1 is detected by the sensors 12 and 13, a detection signal is sent to the control device, and the control device integrates the amount of rotation of the motor 15 and converts it into the amount of movement of the cassette mounting table 6. This is done by controlling the motor 15.

Repeat the above-described operation to remove wafer 2 in cassette 1.
are carried out sequentially from the bottom.

Note that the height of the contact portion 4 of the arm 3 is such that when the wafer 2a is placed in the stirrup on the arm 3, the upper wafer 2b is displaced and protrudes from the inside of the cassette 1, as shown in FIG. Even if the wafer 2b is in contact with the upper wafer 2b, a gap α1 is provided to prevent the wafer 2b from hitting the upper wafer 2b. The height H of the contact portion 4 and the wafers 2a, 2b are set in the following relationship. Furthermore, the fifth
In the figure, 2b indicates the upper wafer after movement, and 2b'
indicates the upper wafer before movement, 2a indicates the lower wafer after movement, 2a'' indicates the lower wafer before movement, 2a''
indicates the position assuming that the lower wafer is not placed on the arm 3 and descends as it is.

P-(α.+αl)<H<δ−−−−−−− (1
) Here, H: Height of the contact portion 4 from the top surface of the wafer support member 23 P: Wafer storage groove pitch in the cassette 1 δ: Gap between the top surface of the wafer support member 23 and the bottom surface of the wafer 2a when the arm 3 is inserted α0 : Amount of movement of wafer 2a when placing wafer 2a on arm 3 (α,=S−δ) α1 : Lower surface of wafer 2b and contact portion 4 after cassette l has been moved
Minimum gap S with the upper surface: This is the amount of movement of the cassette 1 when placing the wafer 2a on the arm 3.

As described above, according to the embodiment, the contact portion 4 provided on the arm 3
By pressing the wafer 2 against the rollers 22 provided at predetermined intervals, the wafer 2 can be positioned at a predetermined position relative to the arm 3 each time the wafer 2 is carried out. Since the amount of displacement is small, the generation of particles can be suppressed, and reliable and clean transport can be performed.

Further, since the wafer 2 is pushed out by the roller 22 while the wafer 2 is placed in the groove of the cassette 1, there is less contact between the wafer 2 and the groove of the cassette 1, and the generation of particles can be reduced. .

Further, since the roller 22 is used to push out the wafer 2, the wafer 2 and the roller 22 come into contact with each other by rolling, and the generation of particles is extremely reduced.

Furthermore, since a non-slip wafer support member 23 is attached to the wafer 2 placement portion of the arm 3, the wafer 2 will not shift when the positioned wafer 2 is carried out from the cassette (1).

Furthermore, since the leaf spring 20 is interposed between the roller 22 and the air cylinder 19 that moves the roller 22, the wafer 2
Damage to the wafer 2 can be prevented without applying a strong impact to the wafer 2. The leaf spring 20 can be replaced with another one as long as it can absorb the double duty.

In addition, in the tree embodiment, the cassette 1 is lowered and the wafer 2
Although the configuration is such that the wafer 2 is placed a on the arm 3, the arm 3 may be raised to place the wafer 2 thereon.

Furthermore, although this embodiment has been described with respect to the case where the wafer is carried out from within the cassette, the case where the wafer is positioned and carried is not limited to this.

〔Effect of the invention〕

According to the present invention, it is possible to easily perform positioning while placing the wafer on the arm without performing positioning by aligning the orientation flat, it is possible to reliably position each wafer, and it is also possible to prevent particles. This has the effect of being able to perform a highly reliable and clean in-1 test because the occurrence can be suppressed and treated.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing a wafer transfer device that is an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1 taken from A-A, and FIGS. 6 to 8 are plan views showing how the wafer is positioned. 1-----1 cassette, 2--1--wafer, 3-
------Arm, 4-----1 contact part, 5--1-
- Wafer detection sensor, 6-----Cassette mounting table, 19--1--Air cylinder, 22-----
1 Rollei 3 Figure 5

Claims (1)

[Claims] 1. In a wafer transfer device that places and transfers a wafer on an arm, a wafer contact portion is provided at the end of the wafer placement surface on the base side of the arm, and the wafer placed on the arm is The arm is provided with at least two or more rollers that press against the abutting portion from the tip side, the abutting portion is shaped like an arc along the circumferential side of the wafer, and the chord width of the arc is at least orientation flat. (below,"
It's called OriFura. ), and the roller is arranged so that the wafer can be positioned on the arm by mutual alignment between the contact portion and the roller.