JP2003243476A - Unmanned conveying cart - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To release the suction and holding of a wafer by a transfer means in an emergency of a power failure or the like, in an unmanned conveying cart which comprises the transfer means for transferring a wafer, and a sucking and holding means for sucking and holding the wafer at a support part of the transfer means, the sucking and holding means comprising a suction hole formed in the support part of the transfer means, a negative pressure producing means for producing negative pressure, and a holding valve disposed between the suction hole and the negative pressure producing means. <P>SOLUTION: A releasing means for releasing the suction and holding of a wafer is provided in a sucking and holding means. Specifically, a negative pressure producing device 6 as a negative pressure producing means is constituted by an air compressor 61 and vacuum ejectors 65U, 65L, and the releasing means is constituted by open valves 68U, 68L provided between holding valves 67U, 67L and suction holes of transfer hands 31U, 31L. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automated guided vehicle provided with a transfer means for transferring a wafer and a suction holding means for holding a wafer by a supporting portion of the transfer means, and more specifically, to a power failure. The present invention relates to a technique of releasing suction / holding of a wafer in an emergency such as.

[0002]

2. Description of the Related Art In a semiconductor manufacturing factory where dust generation is a problem, transfer means for transferring a semiconductor wafer, a buffer cassette for temporarily storing the wafer, and a posture / direction of the wafer are used for transferring the semiconductor wafer. A technique for automatically driving an automated guided vehicle equipped with an attitude adjusting device for aligning the vehicle is being studied. Most of the power supply to the transfer vehicle is a non-contact power supply method. The transfer vehicle stores wafers in a buffer cassette, transfers the wafers to a predetermined processing apparatus, and transfers the wafers from the buffer cassette by a transfer unit. Take out the wafers one by one,
The device is set on the posture adjusting device, and after being oriented in a predetermined posture / direction, it is transferred to the processing device.

When the wafer is transferred, if the wafer is picked up by the supporting portion of the transferring means and simply placed on the supporting portion, the wafer may be dropped due to a centrifugal force when the transferring means is bent and stretched. Therefore, by operating the suction holding means,
It has been considered to suck and hold the wafer on the supporting portion of the transfer means. The suction holding means is provided between the suction hole formed in the supporting portion of the transfer means, the negative pressure generating means including an air compressor, the supply valve, and the vacuum ejector, and the suction hole and the negative pressure generating means. Holding valve and
The suction holding means will be described below.

The vacuum ejector has a structure having two inlets consisting of a high pressure port and a low pressure port and one outlet, and a pipe from an air compressor is connected to the high pressure port via a supply valve. The pipe from the suction hole of the transfer means is connected to the via a holding valve. This supply valve,
The holding valve is composed of an electromagnetic valve and is electrically opened and closed. In addition, the air is exhausted to the outside by piping from the outlet of each vacuum ejector toward the discharge port.

With such a structure, when the supply valve and the holding valve are open, high-speed air from the air tank is supplied from the high pressure port at one inlet of the vacuum ejector and discharged from the outlet. The high-speed air is attracted, and the air is also sucked from the low pressure port which is the other inlet. The air sucked from the low pressure port and the high speed air supplied to the high pressure port are both discharged from the outlet to the outside through the discharge port.

As a result, air is sucked from the suction holes of the supporting portion of the transfer means, and the wafer on the supporting portion is sucked.
The suction hole of the support portion of the transfer means is sealed by the wafer on the support portion, and when the pipe from the suction hole to the vacuum ejector is depressurized to a predetermined pressure or less, the holding valve is closed. The negative pressure is maintained in the pipe from the holding valve to the suction hole, and the wafer is held by the supporting portion of the transfer means.

Further, when releasing the suction / holding, the supply valve is closed so that high-speed air is not supplied to the high pressure port of the vacuum ejector.
Open the holding valve. As a result, the piping between the discharge port that communicates with the outside, the vacuum ejector, and the suction hole of the support portion of the transfer unit rises to atmospheric pressure, and suction / suction of the wafer is performed.
The hold is released.

[0008]

By the way, in the state where the wafer is held by the supporting portion of the transfer means, if the power supply to the carrier is stopped due to a failure of the power supply device, the supply valve is closed. At the same time, the holding valve remains closed, and the wafer remains sucked and held on the transfer means. At this time, the power supply system of the automated guided vehicle and the processing apparatus may be different, and the processing apparatus may be operating normally. In this case, the wafer on the transfer means may be processed manually. I want to give it to the device. However, the wafer sucked and held on the transfer means cannot be easily removed, and if it is forcibly removed, the wafer may be damaged. For this reason, there is a problem that the workability and the maintainability are not good because there is no choice but to wait until the power supply to the carrier is restored, and the workability and the maintainability are poor.

[0009]

The problem to be solved by the present invention is as described above, and the means for solving this problem will be described below. First, as described in claim 1,
A transfer means for transferring the wafer; and a suction holding means for sucking and holding the wafer by a support portion of the transfer means, wherein the suction holding means includes a suction hole formed in the support portion of the transfer means. In an automatic guided vehicle having negative pressure generating means for generating a negative pressure and a holding valve provided between the suction hole and the negative pressure generating means, a holding means for releasing the suction holding of the wafer by the suction holding means. A release means is provided.

Further, as described in claim 2, a plurality of transfer means for transferring the wafer and suction holding means for sucking and holding the wafer on the supporting portion of each transfer means are provided, and the suction means is provided. The holding means includes a suction hole formed in the support portion for each transfer means, a negative pressure generation means for generating a negative pressure, and a suction hole for each transfer means and the negative pressure generation means. In the automatic guided vehicle constituted by the provided holding valve, the suction holding means is provided with holding releasing means for independently releasing the suction holding of the wafer for each transfer means.

According to a third aspect of the present invention, the negative pressure generating means is composed of an air compressor and a vacuum ejector, and the holding releasing means is a suction portion of the holding valve and the supporting portion of the transfer means. It is composed of an open valve provided between the hole and the hole.

[0012]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will now be described with reference to the drawings. Figure 1 shows an automated guided vehicle 1.
Is a side view, FIG. 2 is a plan view of the single wafer transfer device 3, and FIG. 3 is a circuit diagram showing a piping configuration of the negative pressure generation device 6.

First, the overall structure of the automated guided vehicle 1 will be described. The automated guided vehicle 1 shown in FIG.
20 is a track guided vehicle that automatically travels on the vehicle 20, and the vehicle body 2 is supported by traveling wheels 9.9.9. The transport vehicle 1 of this configuration has all the traveling wheels 9 and 9 in order to reduce slip.
-It is configured by four-wheel drive so as to transmit the drive to 9/9, and a drive motor is attached to each traveling wheel 9/9/9/9, but all traveling wheels 9/9/9 The mechanism for transmitting drive to 9 is not limited to this, and may be another mechanism. The number of drive wheels is not limited to four as long as they are provided in the front and rear of the vehicle body, respectively.

A feed line holder is provided on one of the traveling rails 20, and the feed line is held at the upper end of the feed line holder. A high-frequency current is applied to the power supply line from a power supply board, which causes a magnetic field to be generated around the power supply line, and the power receiving unit 25 fixed to the carrier 1 generates the magnetic field. Taking out induced electromotive force. Then, the extracted current is amplified, converted into a predetermined voltage, rectified and smoothed, and the control device of the transport vehicle 1 and the traveling wheels 9
Power is being supplied to the drive motor, etc. Further, processing devices, automatic warehouses, and the like are arranged along the traveling rails 20.

A wafer transfer device 3 for transferring the wafers 10 one by one is arranged in the center of the body 2 of the carrier vehicle 1, and the posture, direction and center position of the wafer 10 are arranged before and after the transfer device 3. An attitude aligning device 4 for aligning and a support base 5 for supporting a buffer cassette 50 accommodating the wafer 10 are provided. A large number of shelves are provided vertically in the buffer cassette 50, and the wafers 10, 10, ... Are horizontally accommodated in each shelf.

At the opening of the buffer cassette 50 facing the single wafer transfer device 3, the wafers 10, 10 ...
Rod 55 as a pressing member for pressing the edge of the
Is erected. The stopper rod 55 is configured to be movable between one side end position of the opening portion of the buffer cassette 50 and the left and right center position, and when the transport vehicle 1 travels, an air cylinder is operated, The stopper rod 5
5 is moved to the left and right center position of the opening of the buffer cassette 50 and brought into contact with the edges of the wafers 10, 10 ... Stored in the buffer cassette 50 to accelerate or decelerate the wafer 10. 10 is prevented from popping out. On the other hand, when the wafers 10 are transferred, the stopper rod 55 is retracted to one end position of the buffer cassette 50 so as not to obstruct the loading and unloading of the wafers 10.

Next, the single wafer transfer device 3 will be described. As shown in FIGS. 1 and 2, the single wafer transfer device 3
Is composed of transfer arms 30U and 30L as transfer means, a base 38, a turntable 39, and the like. The base 38 is embedded in the center of the vehicle body 2, and the turntable 39 is pivotally mounted on the base 38. A pair of transfer arms 30U and 30L are mounted on the turntable 39.

The base 38 is configured to be movable up and down, and the turntable 39 is configured to be rotatable relative to the base 38. The transfer arm 30U (30L) is
The transfer hand 31U (31L) and the first arm 32U (3
2L) and the second arm 33U (33L) is a scalar arm type robot hand in which a link mechanism is assembled.
Then, when the first arm 32U (32L) rotates by an angle of θ by an actuator composed of a servo motor or the like,
The second arm 33U (33L) is replaced by the first arm 32U (32
The rotation of the transfer hand 31U (31L) is performed in the opposite direction to the rotation of L), and the transfer hand 31U (31L) is also rotated in the same direction as the rotation of the first arm 32U (32L) by the θ angle. Therefore, the transfer hand 31U (31L) apparently moves linearly.

The transfer hand 31U (31L) has a plan view,
A member that supports the wafer 10 and is formed in a substantially "concave" plate shape.
4 and 34 are provided, and suction is performed by the negative pressure generating device 6 described later. At the time of transfer, the wafer 10 is picked up by the transfer hand 31U (31L), is sucked by the suction holes 34, 34, and is held so as not to fall, while the transfer arm 30U (30L) is expanded or contracted. It is transferred by raising and lowering the base 38 and rotating the turntable 23. Then, when the wafer 10 is placed at a predetermined position, the suction in the suction holes 34 is released.

Next, the posture adjusting device 4 will be described. The attitude adjusting device 4 includes a casing 40 and a mounting table 4.
1, a linear sensor 42, 42, an optical character reader (hereinafter referred to as "OCR") 43, etc., and the casing 40 has an opening on the single-wafer transfer device 3 side, and two sets of the linear sensor 42, 42 are provided near the entrance thereof. Are arranged, and a light projector 42a is arranged on the ceiling side and a light receiver 42b is arranged on the floor side. These two sets of linear sensors 42
Is a notch position 10a such as an orientation flat position or a notch position of the wafer 10 of 12 inches, which is detected by the linear sensor 42 on the outer side (opening inlet side of the casing 40), and the linear sensor 42 on the inner side (back side of the opening of the casing 40). Is configured to detect the orientation flat position of the 8-inch wafer 10 or the notch position 10a such as the notch position.

On the inner side of the opening of the casing 40, O
In the case where the CR 43 is embedded and the wafer 10 is set in the casing 40 with the surface having the ID mark 11 facing downward, the wafer 10 is set so that the ID mark 11 can be read by the OCR 43. Position it on the lower side. In addition, the wafer 1 with the surface with the ID mark 11 facing upward
When 0 is set, the OCR 43 is located above the wafer 10. Then, on both sides of the wafer 10, I
When the D mark is attached, it is preferable to arrange a pair of upper and lower OCRs 43 on the inner side of the casing 40.

In the casing 40, the wafer 10 is
A mounting table 41 for mounting the is installed. The mounting table 41
Has a disk shape, a suction hole is provided at the center of rotation thereof, and a plurality of suction grooves are provided concentrically and radially from the suction hole. With such a configuration, the wafer 10
The wafer 10 is attracted and held by sucking the negative pressure generating device 6 from the suction hole in a state where the wafer is placed on the mounting table 41, and when the mounting table 41 is rotated, the wafer 10 is positioned by the centrifugal force. I try not to slip.

Next, the negative pressure generator 6 will be described. The negative pressure generator 6 includes an air compressor 61, an air tank 62, supply valves 63U, 63L, 64, vacuum ejectors 65U, 65L, 66, and pipes connecting them, and as shown in FIG. Compressor 6
The main body of the negative pressure generating device 6 including the air tank 1 and the air tank 62 is placed and stored in the vehicle body 2 below the buffer cassette 50. As shown in FIG. 3, the piping on the downstream side of the air tank 62 is branched so that the supply valve 63U
・ Vacuum ejector 65U ・ 65L via 63L ・ 64
66 is connected to the vacuum ejector 65U toward the suction holes 34 of the transfer hand 30U, and the vacuum ejector 65L is connected to the suction hole 34 of the transfer hand 30L.
-Piping toward 34, and from the vacuum ejector 66 toward the suction hole on the mounting table 41 of the posture alignment device 4.

The pipe branched on the downstream side of the air tank 62 is provided with the buffer cassette 50 in addition to the above members.
It is also connected to an air cylinder or the like that slides a stopper rod 55 provided in the opening of the.

The air stored in the air tank 62 is squeezed out by the air compressor 61, branched, and then pressure-fed to the vacuum ejectors 65U, 65L, 66 through the respective supply valves 63U, 63L, 64. The supply valves 63U, 63L, 64 are electromagnetic valves, and are electrically opened and closed. Reference numeral 6 in the figure
A drain tank 9 is connected to the air tank 62.

Each vacuum ejector 65U (65L, 66)
Is a high pressure port 65a (65a, 66a) and a low pressure port 65b (6
5b, 66b) and one outlet 6
5c (65c, 66c) and the high pressure port 6
Pipes from the air compressor 61 are connected to 5a, 65a and 66a, and suction ports 34 and 34 of the transfer hand 31U and suction holes 34 and 34 of the transfer hand 31L are connected to the low pressure ports 65b, 65b and 66b, respectively. The pipe from the suction hole of the mounting table 41 is connected. The vacuum ejector 65
A holding valve 67U (67) is provided between the low pressure port of U (65L) and the suction holes 34, 34 of the transfer hand 31U (31L).
L) is provided. This holding valve 67U / 67L
Is also composed of an electromagnetic valve. Also, the outlets 65c, 65c, 66c of the vacuum ejectors 65U, 65L, 66, respectively.
It is configured to be piped from the outlet to the discharge port, and air is exhausted to the external space.

The supply valve 63U (63L, 64) is open, and in the single wafer transfer device 3, the holding valve 67U (67L) is also open, and the high-speed air from the air tank 62 is vacuumed. Ejector 65U (65L, 66)
When supplied from the high pressure port 65a (65a, 66a) at one inlet and discharged from the outlet 65c (65c, 66c), the high speed air is attracted to the low pressure port 65b (at the other inlet). Air is also sucked from 65b and 66b). And this low pressure port 65b (65b, 66b)
Air sucked from the high pressure port 65a (65a, 66a)
The high-speed air supplied to both the outlets 65c (65c,
The gas is discharged from 66c) to the external space through the discharge port.

With such a structure, the suction holes 34, 34 of the transfer hand 31U (the suction holes 34.3 of the transfer hand 31U)
4. Air is sucked from the suction holes of the mounting table 41, and the wafer 10 on the transfer hand 31U (transfer hand 31L, mounting table 41) is held. In the single-wafer transfer device 3, the suction holes 34, 34 are sealed from the suction holes 34, 34 by the wafer 10 placed on the transfer hand 31U (31L).
When the piping up to is reduced to a predetermined pressure or less, the holding valve 67U (67L) is closed, and the holding valve 67U is closed.
The piping from (67L) to the suction holes 34, 34 is maintained at a negative pressure, and the transfer hand 31U (transfer hand 31L)
The wafer 10 is held on top.

When the suction / holding of the wafer 10 is released, the supply valve 63U (63L) is closed so that the high pressure port 65a of the vacuum ejector 65U (65L) is closed.
High-speed air is no longer supplied to and the holding valve 67U (67L) is opened. As a result, the discharge port communicating with the external space and the vacuum ejector 65U (65U
L) and the suction holes 34, 34 of the transfer hand 31U (suction holes 34, 34 of the transfer hand 31U), the pressure in the pipe increases to atmospheric pressure, and the suction / holding of the wafer 10 is released. To be done.

On the other hand, the mounting table 41 of the attitude adjusting device 4 is
A suction hole is provided at the center of rotation, and a plurality of suction grooves are provided concentrically and radially from the suction hole. Therefore, between the wafer 10 on the mounting table 41 and the suction hole. Since a gap is formed through the suction groove and the pipe from the suction hole to the vacuum ejector 66 cannot be maintained at a negative pressure, the wafer 10 is sucked and held on the mounting table 41 by always sucking. There is.

When the suction / holding of the wafer 10 is released, the supply valve 64 is closed, so that high-speed air is not supplied to the high pressure port 66a of the vacuum ejector 66, and the air is suctioned from the low pressure port 66b. As a result, the pressure in the pipe from the discharge port communicating with the external space to the suction hole of the mounting table 41 rises to atmospheric pressure,
The suction / holding of the wafer 10 is released.

When the transfer hand 31U (31L) is holding the wafer 10 and the power supply to the transport vehicle 1 is stopped due to a failure of the power supply device, the supply valves 63U, 63L, 64 are turned on. While being closed, the holding valves 67U and 67L remain closed, and the wafer 10 remains sucked and held on the transfer means.
At this time, the power supply system of the automatic guided vehicle 1 and the processing apparatus may be different, and the processing apparatus may be operating normally. In this case, the wafer 10 on the transfer hand 31U (31L) is Sometimes it is necessary to hand it over to the processor even manually.

However, this transfer hand 31U (3
The wafer 10 sucked and held on the 1L) is transferred to the transfer hand 31U during the transfer operation of the transfer hand 31U (31L).
Since it is held with a sufficient suction force so that the mounting position does not shift on (31L), it cannot be easily removed, and if it is forcibly removed, the wafer 10 may be damaged. For this reason, there is no choice but to wait unnecessarily until the power supply to the transport vehicle 1 is restored, and workability and maintainability are poor.

Therefore, in the present invention, as shown in FIG.
The holding valve 67U (67L) and the transfer hand 31
A pipe is branched between the U (31L) and the suction holes 34, 34, the branched pipe is communicated with the external space, and an open valve 68U (68) is provided on the branched pipe.
L) is installed. It is preferable that the open valves 68U and 68L are mechanical valves so that they can operate without power supply. Further, it is preferable that the opening / closing switches of the opening valves 68U and 68L are arranged at a location such as a front side or a rear side of the vehicle body 2 which is easily operated by an operator. The open valves 68U and 68L may be electromagnetic valves operated by another emergency power source, for example. Specifically, the release valves 68U and 68L include
A secondary battery, which can be constantly charged by the electric power from the contactless power supply, is provided without directly using the electric power extracted by the power receiving unit 25 from the power supply line installed along the traveling rail 20 in a contactless manner. It is conceivable to configure it so that electric power is supplied.

With this structure, the transfer hand 31U (3
(1L) holding the wafer 10 and the power supply to the carrier 1 is stopped, the holding valve 67U (67L) remains closed, and when it cannot be opened, the opening / closing switch is operated to open the opening valve. I will open 68U (68L). As a result, the suction holes 34 of the transfer hand 31U
The pipe pressure from 34 (the suction holes 34 of the transfer hand 31U) to the discharge port communicating with the external space rises to the atmospheric pressure, and as a result, the suction / holding of the wafer 10 is released.

As described above, in the present invention, the transfer hand 31
The suction / holding of the wafers 10/10 by the U / 31L can be easily released at a predetermined timing at any time, and this release can be performed independently for each transfer hand 31U / 31L. , And maintainability is improved.

The present invention is not limited to the unmanned guided vehicle 1 traveling on the traveling rails 20 and 20 by non-contact power supply, and may be, for example, a laser equipped with a battery or a magnetic guided unmanned guided vehicle. It can also be used for automated guided vehicles.

[0038]

Since the present invention is constructed as described above,
The following effects are achieved. First, as in claim 1, there is provided a transfer means for transferring the wafer, and a suction holding means for sucking and holding the wafer by a supporting portion of the transfer means, and the suction holding means of the transfer means. A suction hole formed in the support part,
In an automatic guided vehicle having negative pressure generating means for generating a negative pressure and a holding valve provided between the suction hole and the negative pressure generating means, a holding means for releasing the suction holding of the wafer by the suction holding means. By providing the releasing means, the suction holding of the wafer by the supporting portion of the transferring means can be easily released at a predetermined timing at any time even when an abnormality occurs such as power supply to the transport vehicle is stopped, Workability and maintainability are improved.

Further, as in claim 2, a plurality of transfer means for transferring the wafer, and a suction holding means for holding the wafer by suction on a support portion of each transfer means are provided, and the suction holding means. Is a suction hole formed in the support portion for each transfer means,
In an automated guided vehicle composed of negative pressure generating means for generating a negative pressure, and a holding valve provided between the suction hole and the negative pressure generating means for each transfer means, in the suction holding means,
By providing holding release means for independently releasing the suction holding of the wafer for each transfer means, even when an abnormality occurs such as the stop of power supply to the transfer vehicle, the wafer is supported by the support means of the transfer means. The suction holding can be easily released at a predetermined timing at any time, and this releasing can be performed independently for each transfer means, which improves workability and maintainability.

According to a third aspect of the invention, the negative pressure generating means is composed of an air compressor and a vacuum ejector, and the holding releasing means is the holding valve and the suction hole of the supporting portion of the transfer means. The negative pressure generating means can be made compact and the holding releasing means can be made simple by constituting the opening valve provided between the two. For this reason, it is possible to prevent the unmanned guided vehicle body from increasing in size and to stop the power supply to the guided vehicle.
When an abnormality occurs, the opening valve is opened manually to easily release the suction holding of the wafer by the supporting portion of the transfer means at a predetermined timing, thereby improving workability and maintainability. be able to.

[Brief description of drawings]

FIG. 1 is a side view of an automated guided vehicle 1.

FIG. 2 is a plan view of the single-wafer transfer device 3.

FIG. 3 is a circuit diagram showing a piping configuration of a negative pressure generator 6.

[Explanation of symbols]

1 carrier 2 Body 3 Transfer device 4 Positioning device 6 Negative pressure generator 21 Placement surface 31U Transfer Hand 31L transfer hand 34 Suction hole 61 Air compressor 62 air tank 63U supply valve 63L supply valve 64 supply valve 65U vacuum ejector 65L vacuum ejector 66 Vacuum ejector 67U holding valve 67L holding valve 68U release valve 68L open valve

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Isao Fukuda             Murata Machine, 136 Takeda Mukoyo-cho, Fushimi-ku, Kyoto             Machine Co., Ltd. Headquarters factory F term (reference) 5F031 CA02 DA01 FA01 FA11 FA13                       GA03 GA08 GA38 GA43 GA50                       GA58 KA12 PA06 PA30

Claims (3)

[Claims] 1. A transfer means for transferring a wafer, and a suction holding means for sucking and holding a wafer by a supporting portion of the transferring means, wherein the suction holding means is formed on a supporting portion of the transferring means. In the automatic guided vehicle including the suction holes, the negative pressure generating means for generating a negative pressure, and the holding valve provided between the suction holes and the negative pressure generating means, the suction holding means sucks the wafer. An automatic guided vehicle, which is provided with holding releasing means for releasing holding. 2. A plurality of transfer means for transferring a wafer, and a suction holding means for sucking and holding a wafer on a support portion of each transfer means, wherein the suction holding means is provided for each transfer means. And a suction valve formed in the support portion, negative pressure generating means for generating a negative pressure, and a holding valve provided between the suction hole and the negative pressure generating means for each transfer means. In the automatic guided vehicle, the suction holding means is provided with a holding release means for independently releasing the suction holding of the wafer for each transfer means. 3. The negative pressure generating means is composed of an air compressor and a vacuum ejector, and the holding releasing means is provided between the holding valve and a suction hole of a supporting portion of the transfer means, and is opened. The automatic guided vehicle according to claim 1 or 2, wherein the automatic guided vehicle comprises a valve.