JPS62106641A - Wafer aligning unit - Google Patents

Abstract

PURPOSE:To lower probabilities for a wafer to be damaged by a method wherein a sensor capable of detecting if a wafer is out of a cassette insertion/ extraction opening is provided for the accomplishment of aligning only when a wafer is out of the opening. CONSTITUTION:A beam 18 emitted by a sensor 16 at the light-emitting side is received by a sensor 17 on the light-receiving side. A wafer 4 out of a wafer cassette 5 stops the beam 18. This causes a pusher 15 to go into operation, which in turn causes a mount 6, push-up platform 13, and eccentric cam 7 to go into motion for the rotation of the wafer cassette 5 around shaft support members 9 and 14. As the result, the wafer cassette 5 is inclined with its wafer insertion/extraction opening up. A motor drives the eccentric cam 7 and the wafer cassette 5 is thrown into a rocking motion for the alignment of wafers 4 in the wafer cassette 5. A spring 8 expands and contracts in response to the eccentric cam 7 in rotation, pushing a mount 6 against the eccentric cam 7. After the rocking, the wafer cassette 5 is allowed to return to its original attitude.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field 1 of the Invention] The present invention relates to a wafer alignment device, and more particularly, to a wafer alignment device for IC, LS,
The present invention relates to a device for aligning wafers in a wafer cassette in a wafer transfer device using a linear hand to insert wafers IIQ from a wafer cassette (wafer storage box) used in a manufacturing process such as I.

[Prior Art] Conventionally, in the transportation of wafers in semiconductor manufacturing equipment, a method is often used in which a linear hand is inserted from the wafer insertion/ejection port side. This is a method in which the wafer is placed directly on the hand from the wafer cassette without being taken out. According to this method, it is possible to take out wafers from any part of the wafer cabinet and return them to the same position, so all cassettes can be used for both supply and collection, which has the advantage of making the equipment more compact. be.

FIG. 3 shows a schematic configuration of a conventional wafer transfer device. In the figure, 1 is a straight hand, and 2 is a drive section of the straight hand 1. Further, 4 is a wafer, 5 is a wafer cassette for storing the wafer 4, and 6 is a stand for unloading the wafer cassettes 1 to 5. 19 indicates the moving direction of the hand 1.

By the way, in such a method using a straight hand, it is necessary to place the wafer on the hand almost properly. This is because if the wafer protrudes too much from the wafer cassette, various problems will occur. For example, at the wafer insertion/ejection port, the hand moves up and down (arrow 19 in Figure 3) to take out the wafer.
direction), there is a risk of damaging the wafer. In addition, the wafer may be misplaced on the hand, and when attempting to mount the wafer on the chuck in the next process, the wafer may move away from the vacuum suction groove and cannot be properly inserted. When attempting to do so, the wafer end face protrudes from the detection range and cannot be detected properly.Also, even if the wafer is aligned at a predetermined position within the wafer case, it may pop out again due to equipment vibration, etc. there were.

Therefore, it is necessary to once align the wafers prior to the wafer ejection operation. For this reason, conventionally, the wafer cassette had to be manually tilted once with the insertion/ejection port side facing upward.
Thereafter, the wafer cassettes 1 to 1 were swung to align the wafers. This method has the disadvantage that vibrations are frequently applied to the wafer, which increases the probability of damaging the wafer.

[Object of the Invention] In view of the above-mentioned problems with the conventional type, the present invention provides a sensor for detecting the presence or absence of a wafer at a certain distance from the ideal wafer alignment position of the wafer insertion/ejection opening, and detects the presence of the wafer. Based on the concept of aligning the wafers by tilting the wafer cassettes 1 to 1 only when there are wafers, that is, when the wafers have jumped out of the cassette, the wafers have jumped out of the cassette insertion/ejection opening. The purpose of this invention is to significantly reduce the damage to the wafer that occurs due to this, and to reduce the probability of single-member damage to the wafer as a whole.

[Summary of the Invention 1 In order to achieve the above object, the wafer alignment device of the present invention has the following features:
A straight-advancing hand is provided at a position opposite to the wafer on the wafer insertion/ejection opening side of the cassette to take out the wafer from the wafer cassette, and the hand is inserted into the cassette so as not to touch the wafer, and the hand is moved in a direction perpendicular to the direction of entry. move,
In a wafer transport device in which a wafer is placed on a hand and then the hand is pulled out to the wafer insertion/ejection port side of a cassette to take out the wafer, the wafer is placed at a position a certain amount away from the ideal alignment position of the wafers on the wafer insertion/ejection port side. A detection means capable of detecting the presence or absence of a wafer is provided to detect the presence or absence of a wafer prior to the operation of ejecting the wafer.If there is no wafer, the hand is inserted into the wafer cassette.If there is no wafer, the hand is inserted into the wafer cassette. The wafer is then taken out.

[Description of Example 1 Hereinafter, the present invention will be explained in detail using the drawings.

1 and 2 show the configuration of a wafer alignment apparatus according to an embodiment of the present invention.It should be noted that parts common or corresponding to those of the conventional example are designated by the same reference numerals. In FIG. 1.2, 2 is a drive unit for the linear hand 1, and the wafer 4 is placed in a cassette 5.
It is also a detection mechanism for detecting which part of the body it is in. Similarly to the detection mechanism section 2, 3 is a mirror for wafer detection.

Further, the table 6 on which the wafer cassette 5 is placed is a cassette]~5
is engaged with. Reference numeral 7 denotes an eccentric cam, which is rotated by a motor (not shown) to give swinging motion to the mounting table 6. A spring 8 is used to press the mounting table 6 against the eccentric cam 7. 10.12 is a member on which the spring 8 is hooked. Reference numeral 9 denotes a shaft support member that becomes the center of rotation when the mounting table 6 is tilted, and similarly, 14 represents a shaft support member that becomes the center of rotation when the push-up table 13 tilts. 11 is a main body member which engages with the shaft support member 9.14. Reference numeral 15 denotes a pusher, which functions to push up the push-up table 13. 16 and 17 are sensors, 16 is a light emitting side, and 17 is a light receiving side. 18
indicates a light beam emitted from 16.

In the above configuration, the operation of wafer alignment will be explained with reference to FIGS. 1-2.

First, a beam 18 is emitted from the light-emitting sensor 16 and received by the light-receiving sensor 17 . The position of the beam 18 is set a certain amount away from the ideal wafer position.

If the wafer 4 protrudes from the wafer cassette 5 as shown in FIG. 2, the beam 18 will be blocked.

As a result, the pusher 15 operates, and the wafer cassette 5 is tilted with the mounting table 6, the push-up table 13, the spaced cam 7, and the shaft support members 9, 14 as rotation centers with the wafer insertion/ejection port facing upward. Thereafter, the eccentric cam 7 is rotated by a motor (not shown) to give a rocking motion to the wafer cassette, and the wafers 4 are reliably aligned in the wafer cassette 5. The spring 8 expands and contracts as the eccentric cam 7 rotates, and presses the mounting table 6 against the eccentric cam 7. After rocking, wafer cassettes 1 to 5 are raised again.

If the wafer does not block the beam 18 as shown in FIG. 1, then no movement of the wafer cassette 5 is performed.

Next, the appropriate position for inserting the straight-moving hand 1 into the unibakazette 5, that is, the position at which the hand 1 should be inserted with respect to the wafer 4 that is the target to be taken out is detected.

This is done by emitting a laser from a laser source (not shown) in the detection mechanism section 2 and shining it on the mirror 3, and detecting the reflected light (not shown) by a detector (not shown). After the detection, the hand 1 enters the cassette 5 and moves upward in the paper plane of FIG.

When the wafer 4 is moved from a shelf member (not shown) in the wafer cassette 5 to the top of the hand 1, a vacuum detection mechanism (not shown) detects that the wafer 4 is securely placed on the hand 1. Thereafter, the wafer 4 is carried out of the cassette. The unloaded wafer is transferred to the next process (not shown).

When returning the wafer to the cassette 5, the wafer is detected before being returned, and if the beam is not blocked, it remains as is, and if it is blocked, the wafer is aligned by tilting and swinging movements, and then the wafer is returned to the cassette 5.

Note that the dimensions must be set so that the beam 18 is not blocked by the hand 1.

That is, it is necessary to prevent the beam 18 from entering the vertical position of the hand 1. However, if the dimension j is made too large, the valve device becomes large. On the other hand, if it is too small, a problem arises in that even if the wafer slightly protrudes from the wafer cassette 5 due to external vibration or the like, tilting and swinging movements must be performed frequently. Therefore, it is best to choose between 3 and 5 breaths.

Although the wafer cassette is not tilted in this embodiment, a special member may be provided for pushing the wafer into the hand without tilting the wafer cassette. However, a sensor is still required in that case.

In addition, in this example, a transmission type was used as the sensor, but
The sensor is not limited to this, and a reflective sensor or the like may be used.

[Effects of the Invention] As explained above, according to the present invention, a sensor is provided to detect when a wafer is ejected from the cassette insertion/ejection opening, and the alignment operation is performed only when a wafer ejects. It is no longer necessary to perform tilting and rocking movements to avoid alignment each time a wafer is inserted or removed, and damage to the wafer due to the wafer being ejected can be greatly reduced, and the probability of damage to the wafer as a whole can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a wafer alignment apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a state in which the wafer slightly protrudes from the wafer cassette and blocks the beam in the above embodiment. , is a schematic configuration diagram of a conventional wafer transfer device. 1: straight hand, 4: wafer, 5: cassette, 7: centrifugal cam, 15: pusher, 16: light emitting sensor, 17: light receiving sensor, 18: beam.

Claims (1)

[Scope of Claims] 1. A device for aligning wafers in a wafer cassette in a straight line with respect to a wafer insertion/ejection port of the cassette, wherein at least one of the wafers stored in the wafer cassette is inserted into the cassette. The wafer position detecting means generates a detection signal when the wafer protrudes beyond a predetermined amount with respect to the ejection port, and the wafer aligning means biases the wafer in the wafer cassette in one direction based on the detection signal. Features of wafer alignment equipment. 2. The wafer aligning device according to claim 1, wherein the aligning means tilts the cassette with the insertion/ejection port side facing upward, and then swings the cassette. 3. The alignment means is configured to prevent the hand from shifting from a predetermined position in the cassette when the hand is inserted into the cassette, and is placed in a position facing the wafer from the insertion/ejection opening side of the cassette. 2. The wafer aligning apparatus according to claim 1, wherein a member is provided to push the wafers into a predetermined position by coming into contact with the outer periphery of the wafers stored in the wafer, thereby aligning the wafers.