JPH06124994A - Transfer equipment of wafer carrier - Google Patents

Abstract

PURPOSE:To obtain the transfer equipment of a wafer carrier which eliminates the decrease of transfer precision due to dimensional change of a buliding with time. CONSTITUTION:First sensing means 9, 10 which detect the distance between a carrier car 4 and a transfer machine 6 are installed. On the basis of the detection results of the first sensing means 9, 10, the movement position of a transfer arm 5 to the transfer machine 6 can be controlled. Second sensing means 11, 12 which detect the traveling position of the carrier car 4 are installed. On the basis of the detection results of the second sensing means 11, 12, the stop position of the carrier car 4 on a carrier route R can be controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer carrier transfer device for transferring a wafer carrier containing a wafer to a predetermined place in a semiconductor wafer automatic transfer system in a semiconductor manufacturing factory.

[0002]

2. Description of the Related Art Generally, a so-called automatic transfer system, which eliminates the intervention of a worker as a dust source, is introduced as a transfer means for a wafer carrier in a semiconductor manufacturing factory. This automatic transfer system is mainly composed of a transfer vehicle that transfers a wafer carrier containing wafers to each process, and a transfer machine that transfers the wafer carrier received from the transfer vehicle to a predetermined location. As a wafer carrier transfer device of this type, there is one disclosed in Japanese Utility Model Laid-Open No. 62-80334 by the present applicant.

FIG. 5 is a perspective view for explaining the conventional wafer carrier transfer device. In the figure, 50 is a guide member, and this guide member 50 is supported by hanging bolts suspended from a ceiling portion (not shown). Further, the guide member 50 forms a transport path R, and a transport vehicle (not shown) travels on the transport path R. Further, a rotatable mounting arm 51 is attached to the transport vehicle, and a wafer carrier 52 is mounted on the mounting arm 51. On the other hand, 53 in the figure is a transfer machine,
The transfer machine 53 is installed on the floor of the building. A transfer arm 54 that can move up and down is attached to the transfer machine 53, and the transfer arm 54 allows the wafer carrier 52 to be moved.
Are transferred to a predetermined place.

Next, the operation of the above-mentioned conventional transfer device will be described. First, in a state where the wafer carrier 52 is mounted on the mounting arm 51, a transport vehicle (not shown) is stopped at a predetermined position on the transport path R. Next, the mounting arm 51 is moved to A
It is turned 90 degrees in the direction of the arrow so that the arrangement is as shown in FIG. Then, the transfer arm 54 of the transfer machine 53 is raised to transfer the wafer carrier 52 from the mounting arm 51 to the transfer arm 54. After that, the mounting arm 51 is rotated in the opposite direction to the previous direction, and the transfer arm 54 is lowered to the lowest position to transfer the wafer carrier 52 onto the mounting table 55. Conventionally, the wafer carrier transfer operation has been performed by the above procedure.

[0005]

However, in the above-mentioned conventional transfer apparatus, a transfer vehicle (not shown) traveling on the transfer path R provided to be connected to the ceiling portion is provided on the other transfer apparatus. Since 53 is installed on the floor portion, the transfer vehicle and the transfer machine 5 on the transfer path R are subject to the dimensional changes of the building over time.
There is a problem in that a relative positional deviation occurs between the wafer carrier 3 and the wafer No. 3 and this lowers the transfer accuracy of the wafer carrier 52.

The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a wafer carrier transfer apparatus which eliminates the decrease in transfer accuracy due to dimensional changes of buildings over time. .

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and is a transport path connected to a ceiling portion of a building, and a transport vehicle traveling on the transport path. A loading arm attached to the carrier, a transfer machine installed on the floor of the building, and a transfer arm attached to the transfer machine. In the wafer carrier transfer device in which the wafer carrier is transferred to and from the transfer arm, first sensor means for detecting the distance between the carrier and the transfer machine is provided,
The advancing / retreating position of the mounting arm with respect to the transfer machine can be controlled based on the detection result from the first sensor means.
Second sensor means for detecting the traveling position of the transport vehicle is provided, and the stop position of the transport vehicle on the transport path can be controlled based on the detection result from the second sensor means.

[0008]

In the wafer carrier transfer apparatus of the present invention, the advancing / retreating position of the mounting arm with respect to the transfer machine is controlled based on the detection result from the first sensor means, and the detection from the second sensor means is performed. By controlling the stop position of the transfer vehicle on the transfer path based on the result, when the wafer carrier is transferred, the mounting arm of the transfer vehicle and the transfer arm of the transfer machine are always in the same arrangement state. As a result, the wafer carrier is always transferred to a fixed position without causing positional variations.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A wafer carrier transfer device according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic plan view illustrating an embodiment of the present invention, and FIG. 2 is a schematic side view of the same. In the figure, reference numeral 1 is a guide member, and the guide member 1 is supported by a pair of left and right suspension bolts 3 suspended from a ceiling 2. The guide member 1 has a hollow structure having a rectangular cross section, and a transport path R is formed in this hollow portion.

The transport path R is provided so as to extend over each process, and the transport vehicle 4 runs on the transport path R. Further, a mounting arm 5 having a substantially U-shaped plane is attached to the transport vehicle 4, and the mounting arm 5 is B-shaped.
The structure is such that it can turn in the direction of arrow and can move back and forth in the direction of arrow C.

On the other hand, reference numeral 6 in the figure is a transfer machine, and this transfer machine 6 is installed on the floor portion (not shown) of the building. A vertically movable transfer arm 7 is attached to the transfer machine 6, and the wafer carrier 8 carried by the carrier 4 is transferred to a predetermined place by the transfer arm 7. .

In the wafer carrier transfer apparatus of this embodiment, first, a first sensor means for detecting the distance between the transfer vehicle 4 and the transfer vehicle 6 is provided. The first sensor means is composed of, for example, an L-shaped reflector 9 and a lightwave type or ultrasonic type distance sensor 10. One of the reflectors 9 is attached to the front right side of the transfer machine 6. The other distance sensor 10 is attached to the tip of the left arm 5a of the mounting arm 5. The reflector 9 and the distance sensor 10 are arranged so as to face each other when the mounting arm 5 on which the wafer carrier 8 is mounted is rotated as shown in FIG.

Further, in this embodiment, second sensor means for detecting the traveling position of the transport vehicle 4 on the transport path R is provided. This second sensor means is composed of, for example, an L-shaped slit plate 11 and a reflection type optical sensor 12, one slit plate 11 being on the opposite side of the above-mentioned reflection plate 9,
That is, it is attached to the left side of the front surface of the transfer machine 6, and the other optical sensor 12 is attached to the tip of the right arm 5b of the placing arm 5. The slit plate 11 and the optical sensor 12 are
Similar to the first sensor means, the mounting arms 5 on which the wafer carriers 8 are mounted are arranged so as to face each other in a state of being swung as shown in FIG.

The detection results from the first and second sensor means are transmitted to a control unit (not shown). The control unit controls the advancing / retreating position of the mounting arm 5 with respect to the transfer device 6 and the stop position of the transport vehicle 4 on the transport path R based on the detection result from each sensor means.

In the structure of the above embodiment, the reflecting plate 9 and the slit plate 11 are mounted on the transfer machine 6 side, and the distance sensor 10 and the optical sensor 11 are mounted on the carrier 4 side, that is, the mounting arm 5. However, the present invention is not limited to this. That is, the reflection plate 9 and the distance sensor 10, and the slit plate 11 and the optical sensor 12 are attached to one or the other of the transport vehicle 4 and the transfer machine 6 while satisfying the above-mentioned arrangement conditions. Just do it.

Next, the operation of the transfer apparatus of this embodiment will be described with reference to the flowchart of FIG. First, when the wafer carrier 8 is transferred from the transfer vehicle 4 to the transfer machine 6, the transfer arm 7 is set to a predetermined height, that is, the transfer vehicle 4 is placed, in preparation for transfer on the transfer machine 6 side. Arm 5
It is made lower than that and waits at a height that does not cause a collision when the mounting arm 5 turns (S1). Subsequently, with the wafer carrier 8 placed on the placing arm 5, the transport vehicle 4 on the transport path R is caused to travel to a pre-teached position (S2).

Next, the mounting arm 5 of the transport vehicle 4 is rotated 90 degrees (S3). At this point, the reflector 9 and the distance sensor 10 which are the first sensor means are in the facing state as shown in FIG. 1, and from this state, the distance between the transport vehicle 4 and the transfer machine 6 is determined by the distance sensor 10. It is detected (S4). Here, the separation distance between the transport vehicle 4 and the transfer machine 6 is detected based on the elapsed time until the laser light or the ultrasonic wave emitted from the distance sensor 10 hits the reflector 9 and returns to the distance sensor 10 again. The detection result is sent from the distance sensor 10 to the control unit.

In the control section, the reference distance data stored in advance and the detection data from the distance sensor 10 are compared and calculated, and the mounting arm 5 is moved back and forth so that both data values match (S5). As a result, the advance / retreat position of the mounting arm 5 with respect to the transfer machine 6 is controlled.

Further, at the above-mentioned time point, the slit plate 11 as the second sensor means and the optical sensor 12 are in the following arrangement state. That is, as shown in FIG. 3, when the traveling direction of the transport vehicle 4 is the D direction, the optical axis focus position P of the optical sensor 12 is substantially the same height as the slits 11a provided at regular intervals in the slit plate 11. Moreover, the slit 11a
It is placed in the unpassed state.

From such an arrangement state, the transport vehicle 4 starts slow speed traveling (S6). At this time, the optical axis focus position P of the optical sensor 12 sequentially shifts in the D direction (FIG. 3), and the optical sensor 12 moves along with the slit 11 along with this.
A pulse signal corresponding to the number of passages of a is transmitted to the control unit.

The control unit sequentially inputs the pulse signals from the optical sensor 12 (S7), and determines whether or not the number of pulses has reached a preset number of pulses (S8). Then, at the same time when the number of input pulses reaches a predetermined number, the low speed traveling of the carrier 4 is stopped (S9). As a result, the stop position of the transport vehicle 4 on the transport path R is controlled.

Then, the transfer arm 7 of the transfer machine 6 is raised to transfer the wafer carrier 8 on the mounting arm 7 to the transfer arm 7 (S10), and the mounting arm 7 is moved to the previous position. Turn in the opposite direction to return to the original position (S1
1). After that, the transfer arm 7 is lowered to the lowest position, and the wafer carrier 8 is transferred to a predetermined place (S12). The transfer operation of the wafer carrier 8 is completed by the above procedure.

As described above, in the transfer apparatus of this embodiment, the forward / backward position of the mounting arm 5 with respect to the transfer machine 6 is controlled based on the detection result from the first sensor means, and the second sensor means is also used. By controlling the stop position of the transport vehicle 4 on the transport path R on the basis of the detection result from, the relative displacement between the transport vehicle 4 and the transfer machine 6 is caused by the dimensional change of the building over time. Even when the wafer carrier 8 is transferred, the mounting arm 5 of the carrier 4 is used to transfer the wafer carrier 8.
And the transfer arm 7 of the transfer machine 6 can always be in the same arrangement state. Therefore, if the wafer carriers 8 are transferred in such an arrangement state, the individual wafer carriers 8 are always transferred to a fixed position without causing positional variations.

In this embodiment, the case where the wafer carrier 8 is transferred from the transfer vehicle 4 to the transfer machine 6 has been described, but by reversing the transfer procedure described above,
The transfer from the transfer machine 6 to the transport vehicle 4 is also easily possible.

[0025]

As described above, according to the transfer apparatus of the present invention, even when a relative positional deviation occurs between the carrier vehicle and the transfer machine, the wafer carrier is transferred. Can always place the mounting arm of the carrier vehicle and the transfer arm of the transfer machine in the same arrangement state. As a result, since the wafer carrier is always transferred to a fixed position without causing positional variations, the decrease in transfer accuracy due to the dimensional change of the building with time is eliminated, and In the automatic transportation system of the semiconductor manufacturing plant,
Higher precision wafer carrier transfer can be expected.

[Brief description of drawings]

FIG. 1 is a schematic plan view illustrating an embodiment of the present invention.

FIG. 2 is a schematic side view illustrating an embodiment of the present invention.

FIG. 3 is a perspective view for explaining a second sensor means.

FIG. 4 is an operation flowchart of the apparatus according to the embodiment.

FIG. 5 is a perspective view illustrating a conventional transfer device.

[Explanation of symbols]

 2 Ceiling 4 Transport Vehicle 5 Mounting Arm 6 Transfer Machine 7 Transfer Arm 8 Wafer Carrier 9 Reflector 10 Distance Sensor 11 Slit Plate 12 Optical Sensor R Transport Path

Claims (3)

[Claims] 1. A transportation path connected to a ceiling portion of a building, a transportation vehicle traveling on the transportation path, a mounting arm attached to the transportation vehicle, and a floor portion of the building. And a transfer arm attached to the transfer machine, and a wafer carrier for transferring the wafer carrier between the transfer arm of the carrier vehicle and the transfer arm of the transfer machine. In the transfer device, the first sensor means for detecting a separation distance between the transport vehicle and the transfer machine is provided, and the transfer machine is preliminarily described based on a detection result from the first sensor means. The forward / backward position of the placing arm is controllable, and second sensor means for detecting the traveling position of the transport vehicle is provided, and the transport vehicle on the transport path is based on the detection result from the second sensor means. Controllable stop position Apparatus for transferring a wafer carrier, wherein the door. 2. The first sensor means is a reflection plate attached to either one of the transport vehicle and the transfer machine, and a distance sensor attached to the other corresponding to the reflection plate. 2. The wafer carrier transfer device according to claim 1, further comprising: 3. The second sensor means includes a slit plate attached to either one of the transport vehicle and the transfer machine, and an optical sensor attached to the other corresponding to the slit plate. 2. The wafer carrier transfer device according to claim 1, further comprising: