JPH05291382A - Thin plate storing apparatus - Google Patents

Abstract

PURPOSE:To provide a thin plate storing apparatus which detects any thin plate projected from a thin plate storage cassette placed on a cassette chuck stage and automatically stores the projected thin plate into the cassette, putting it in place. CONSTITUTION:Any wafer 11 projected from a cassette 10 placed on a cassette chuck stage 1 is detected by a sensor of a projection detecting unit 3. The information of the detection is taken into a controller 8, actuating a tilt drive unit 5. The tilt drive unit 5 gradually tilts the cassette chuck stage 1 backward, and thus tilts the cassette 10 thereon. The cassette is tilted until the projected wafer 11 is stored thereinto and the information of the detection from the sensor of the projection detecting unit 3 is turned off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin plate accommodating device, and more particularly to a thin plate accommodating device used for transporting wafers of semiconductor manufacturing equipment and storing wafers.

[0002]

2. Description of the Related Art A conventional thin plate storage device has a plurality of bars on each of the inner walls facing each other, and a thin plate storage cassette (wafer) for horizontally storing a plurality of thin plates on each of the corresponding bars so as to keep them horizontally. Carrier or wafer cassette) is installed on the cassette mounting table, and each thin plate is taken in and out by a robot hand or the like as needed.

Since the thin plate is simply placed on the crosspiece, it may jump out from a predetermined position to the thin plate outlet side due to vibration during transportation. Japanese Utility Model Laid-Open No. 1-118441 discloses a technique for detecting the presence or protrusion of a thin plate by providing an optical fiber at the tip of a robot hand that allows light to pass in the traveling direction and the up-down direction. When the protrusion of the thin plate is detected, the operation of the robot hand is stopped to prevent the thin plate from being damaged.

[0004]

According to the above-mentioned prior art, when a thin plate storage cassette containing thin plates is placed on the cassette mounting table, the thin plates stored in the cassette are slightly moved manually so that the thin plates do not come out of the cassette. Tilt backwards,
Place it carefully or the robot will tilt the cassette slightly backwards instead of manual labor due to the recent automatic transport system.

Accompanied by popping out of the thin plate due to vibration when the cassette is placed on the cassette mounting table, some cause after the cassette is placed, such as popping out due to vibration, and storage error when the transport robot stores the thin plate in the cassette. If a thin plate pops out, it is detected by a human or detected by a detector attached to the device.

When the protrusion of the thin plate is detected, the thin plate which has been protruded is manually stored in the cassette. Therefore, even if the thin plate can be detected to pop out, the apparatus stops until it is manually stored.

When a transfer robot takes out a thin plate from the cassette or stores it in the cassette without noticing the thin plate popping out, the thin plate may be damaged. SUMMARY OF THE INVENTION An object of the present invention is to provide a thin plate storage device that detects a protruding thin plate from a thin plate storage cassette placed on a cassette mounting table and automatically corrects and stores the protruding thin plate in the cassette. ..

[0008]

In order to achieve the above object, a tilt drive unit for inclining a cassette mounting table and a pop-out attached to the cassette mounting table for detecting that a thin plate is protruding from a thin plate storage cassette A detector,
A control means is provided for controlling the tilt drive unit based on the detection signal from the pop-out detection unit to tilt the cassette mounting table and to store the popped-out thin plate in the thin plate storage cassette.

[0009]

Since the thin plate is placed on the crosspiece of the thin plate storage cassette, the thin plate pops out due to vibration or the like. However, if the thin plate storage cassette is tilted, the thin plate slides on the crosspiece.

The thin plate protruding from the thin plate accommodating cassette placed on the cassette mounting table is detected by the sensor of the protrusion detecting section. This detection information is taken into the control device, the tilt drive section is operated, and the thin plate storage cassette on the cassette mounting table is tilted by gradually tilting the cassette mounting table rearward until the detection information from the sensor of the pop-out detection section disappears. Tilt and store the thin plate.

By providing the cassette mounting table tilt detecting section, it is possible to detect the case where the cassette mounting table is tilted more than a predetermined value,
It is possible to prevent the thin plate storage cassette from falling. Furthermore, when the protrusion of the thin plate is no longer detected, the tilt drive system is operated in the reverse direction until the cassette mounting table is no longer tilted, so that the thin plate storage cassette is returned to the horizontal state and the subsequent work is facilitated. .. Further, it is possible to make it difficult for the thin plate to jump out again after the angle is excessively returned.

A sensor for detecting the presence / absence of a thin plate storage cassette may be provided on the cassette mounting table. If a signal is obtained, the cassette mounting table will continue to tilt unless the signal disappears.Therefore, set a specified value for the tilt detected by the cassette mounting table tilt detection unit, and detect that an error has occurred when the tilt exceeds the specified value. By doing so, it is possible to detect that there is no thin plate storage cassette.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thin plate (wafer) accommodating device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a wafer storage device. 2 is a sectional view taken along the line AA of the wafer storage device shown in FIG.
FIG. 3 is a sectional view of the wafer storage device with the cassette tilted.

In FIG. 1 and FIG. 2, a plurality of crosspieces 12 are provided on opposite side surfaces, and the wafer 11 is housed on each crosspiece 12,
Another cassette 10, which has an opening on one side surface, is placed on the cassette placing table 1, is attached on the cassette placing table 1, and its position is determined by the holding pieces 2 that hold the four corners of the cassette.

The cassette mounting table 1 is rotatably supported by a rotary shaft 6 composed of pins, bearings and the like. The cassette mounting table 1 is also driven at one end in the vertical direction indicated by the Z direction in the drawing by the tilt drive system 5 to variably control the angle θ.

That is, the tilt of the cassette mounting table 1 can be controlled by raising and lowering one end of the cassette mounting table 1 using the tilt drive system 5. The cassette mounting table 1 is generally moved up and down in the Z direction by an elevator drive unit 9 shown in more detail in FIG.

The wafer pop-out detection unit 3 is embedded and installed on the cassette mounting table 1 so as to be arranged immediately before the opening of the cassette 10, and emits straight signals such as light, sound waves and electromagnetic waves from below to above. When light, sound waves, electromagnetic waves, etc. are reflected, they are detected.

When the wafer 11 is ejected from the cassette 10, the light emitted from the wafer ejection detector 3 is reflected by the ejected wafer 11 and the ejection of the wafer is detected without contact. When the wafer jump-out detection unit 3 detects the wafer jump-out, it supplies the detection signal to the control device 8.

Below the cassette mounting table 1, a cassette mounting table inclination detecting section 4 is installed, and a displacement gauge such as an optical reflection displacement meter, an ultrasonic displacement meter, an eddy current displacement meter or the like is used up to the cassette mounting table 1. To detect the distance. This detection signal is also the control device 8
Is supplied to.

The control device 8 includes a wafer jump detection unit 3
From the signal from, the wafer is detected and the tilt drive system 5 is driven to tilt the cassette mounting table 1. The tilted angle can be detected by the cassette mounting table tilt detection unit 4.

The correction and storage of the jumping out of the wafer from the wafer storage device is performed as follows. As shown in FIG. 2, when the cassette 10 is mounted on the cassette mounting table 1, a signal emitted from the wafer pop-out detection unit 3, for example, light, travels from the bottom to the top, and if there is a pop-out wafer, It is reflected and the reflected light or the like is detected.

The control device 8 includes a wafer pop-out detection unit 3
The tilt drive system 5 is controlled based on the wafer pop-out detection signal from the cassette mounting table tilt detection information and the cassette mounting table tilt angle information from the cassette mounting table tilt detection unit 4.

That is, first, as shown in FIG. 3, the tilt drive system 5 is driven in the −Z direction to drive the cassette mounting table 1 at an angle downward to the right in the figure. The drive of the tilt drive system 5 is gradually performed until the wafer pop-out detection unit 3 no longer detects the pop-up of the wafer 11 within a preset possible tilt range.

The cassette mounting table 1 has a rotation shaft 6 as the center of θ.
Is rotated in the direction to tilt the cassette 10 backward. When the cassette 10 is tilted, the wafer 11 placed on the crosspiece inside thereof is slid into the cassette 10 by its own weight, and is corrected and stored.

When the ejected wafer 11 is corrected and stored in the cassette 10, the ejection of the wafer 11 is no longer detected by the wafer ejection detector 3, and the signal is supplied to the controller 8.

When the detection of the protruding wafer disappears, the control device 8 drives the tilt drive system 5 in the reverse direction, + Z direction, and returns the cassette mounting table 1 to be horizontal. In this way, the wafer 11 jumped out of the cassette 10.
Are automatically modified and stored.

If the cassette mounting table 1 is returned to the horizontal position, the wafer jump detection unit 3 again causes the wafer 11 to move.
When it is detected that the cassette mounting table has been returned too much, the control device 8 controls the tilt drive system again to correct and store the protrusion of the cassette 11, and the return amount is smaller than the previous amount. Return the cassette mounting table 1 with.

As described above, according to the wafer accommodating apparatus shown in FIGS. 1, 2 and 3, when the wafer is ejected from the cassette, the ejection of the wafer is automatically detected and the wafer is tilted within the cassette. Can be returned to.

The case where the wafer is returned only by tilting the cassette mounting table has been described. However, after tilting the cassette mounting table to some extent, a slight vertical vibration may be applied to drive the wafer into a slippery state. It is possible.

As described above, according to this embodiment,
If the wafer stored in the cassette jumps out for some reason, you can easily correct and store the wafer that has jumped out into the cassette without stopping the production line.

Therefore, when the wafer is taken in and out by the robot, the wafer is not damaged. Further, it is not necessary to manually correct and store the wafer, and automation can be further promoted.

Furthermore, even if the cassette is installed on the cassette mounting table in a tilted state, the wafer is automatically corrected and stored after that, so it is necessary to take great care to prevent the wafer from popping out when the cassette is installed. Is eliminated and workability is improved.

The present invention has been described above with reference to the embodiments.
The present invention is not limited to these. For example,
It will be apparent to those skilled in the art that various modifications, improvements, combinations and the like can be made.

[0034]

As described above, according to the present invention, the protrusion of a thin plate from the inside of the thin plate storing cassette placed on the cassette mounting table is detected, and the protruding thin plate is automatically corrected and stored in the cassette. A thin plate storage device capable of performing the above is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a wafer storage device according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view taken along the line AA of the wafer storage device of FIG.

FIG. 3 is a vertical cross-sectional view taken along the line AA showing the wafer correction / storage operation state of the wafer storage device of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cassette mounting base 2 ... Cassette positioning top 3 ... Wafer protrusion detection unit 4 ... Cassette mounting base tilt detection unit 5 ... Tilt drive system 6 ... Rotation shaft 7 ... Base 8 ... Control device 9 ... Elevator drive unit 10 ... Cassette 11 … Wafer 12… Crosspiece

Claims (2)

[Claims] 1. A thin plate storage device for receiving a thin plate storage cassette, which has a plurality of bars on each of the facing inner walls, and which horizontally houses a plurality of thin plates with a space between them so as to be mounted on the cassette mounting table. A tilt drive unit for inclining the cassette mounting table, a pop-out detection unit that is attached to the cassette mounting table, detects a thin plate protruding from the thin plate storage cassette, and generates a detection signal; A thin plate storage device comprising: a control means for controlling the tilt drive part on the basis of a detection signal from a detection part to incline the cassette mounting table and store the protruding thin plate in a thin plate storage cassette. 2. The thin plate storage device according to claim 1, further comprising an inclination detection unit for detecting the inclination of the cassette mounting table, wherein the control means inclines the cassette mounting table to detect the pop-out detection unit. When the detection signal disappears, the tilt drive unit is controlled, and the tilt of the cassette mounting table is returned until the tilt detection unit obtains a detection signal that the cassette mounting table has returned to a predetermined angle. Storage device.