JPH0611068B2 - Carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a transfer device for transferring an object to be transferred.

(Prior Art) In manufacturing a semiconductor device, there is a step of forming a thin film such as an oxide film on a surface of a semiconductor wafer. When the semiconductor wafer is transferred in this step, a quartz boat accommodating the semiconductor wafer is mounted on a movable table, and the movable table is moved by a drive mechanism.

In order to monitor the operation of the movable table, each sensor signal from various sensors arranged on the movable table is transmitted to a device facing the movable table. This transmission is performed by a flat cable or the like.

Further, the required power source in the movable table is also transmitted to the opposing device by the flat cable used for transmitting the signal.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional technique, when the sensor signals from various sensors arranged on the movable table and the necessary power source on the movable table are transmitted to the opposing device,
Since the signals are transmitted simultaneously by a flat cable or the like, there is a problem that the nozzle overlaps with each signal line and the occurrence of disconnection failure of the flat cable cannot be avoided at all, and the reliability of the operation monitoring of the movable table becomes low. there were.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to move the signals of the respective sensors that monitor the movement of the movable table that changes over time without being affected by the influence of the nozzle or the disconnection. An object of the present invention is to provide a carrier device capable of accurately transmitting to a device facing a table and improving the reliability of operation monitoring of a movable table.

[Structure of Invention]

(Means for Solving the Problems) The present invention relates to a transport device for transporting a movable table for mounting a transported body by a drive mechanism to transport the transported body to a relative device facing the movable table. , The movable table is provided with a transmitter for transmitting an optical signal, and the relative device is provided with a receiver for receiving the optical signal from the transmitter at a position facing the transmitter, and the transmitter is provided with the movable table. Each sensor signal for the operation monitoring of is transmitted as an optical signal, and the receiving unit receives the optical signal from the transmitting unit at least one cycle with two optical signals as one cycle, and two signals in each cycle are received. Only when they match, the matched signal is output to the relative device.

(Operation) According to the present invention, when each sensor signal for monitoring the operation of the movable table is transmitted from the transmitter of the movable table as an optical signal to the receiver of the relative device twice as one cycle, the receiver receives 1 signal. Only when the optical signals of the cycle match, the signal data can be output to the relative device to monitor the state of the movable table. Moreover, since the optical signals are used to transmit the sensor signals, the movable table and No cable is required between the relative devices, and therefore, the relative device can accurately receive each sensor signal at the receiving portion without the influence of the nozzle such as the power source and enhance the reliability of the operation monitoring of the movable table.

(Embodiment) An embodiment of the device of the present invention will be described below with reference to the drawings.

A movable table 2 is provided movably on a guide rail 1 laid linearly in FIG. 1, and the movable table 2 is rotated by a ball screw 3 connected to a drive mechanism (not shown). It is provided so that it can move freely.

An object to be transferred, such as a semiconductor wafer 4, is placed on the movable table 2.
A boat 5 accommodating therein is mounted, and the boat 5 is transported by the movement of the movable table 2.
The movable movable table 2 is provided with a transmitting unit 6 of the optical airborne transmission device, and the device 7 facing the movable table 2 is provided with a receiving unit 8 of the optical airborne transmission device, respectively, at positions facing each other.

The transmitting unit 6 is configured to transmit each sensor signal for monitoring the operation of the movable table 2 as an optical signal. The receiving unit 8 receives the optical signal twice from the transmitting unit 6 as one cycle, and outputs the matched signal data to the relative device 7 only when the optical signals before and after the one cycle match. Is configured. That is, when the first optical signal is received from the transmitting unit 6, the receiving unit 8 stores the signal in the memory, and outputs the data if the next received optical signal matches the first received optical signal. If the second optical signal does not match the first optical signal, this process is repeated anew, and at the time when the preceding and following optical signals match in each cycle, that signal is determined as the movable table operable state. It is configured to output data to the device 7.

Next, a method of transporting the transported object in the above-described transport device will be described.

In FIG. 1, a boat 5 containing a plurality of transferred objects, for example, semiconductor wafers 4, is mounted on a movable table 2. The movable table 2 is moved along a guide rail 1 laid under the movable table 2 by rotation of a ball screw 3 provided in series with a drive mechanism (not shown). By this operation, the semiconductor wafer 4 is transferred.

When the movable table 2 moves, it is necessary to transmit the sensor signals and the like in the movable table 2 to a corresponding device in order to monitor the operation. As the transmission means, a transmitter 6 of the optical air transmission device is provided on the movable table 2 side, and a receiver 8 of the optical air transmission device is provided on the opposite device 7 side at a position facing the transmission unit 6, Each sensor signal or the like in the movable table is transmitted from the transmitter 6 to the receiver 8.

First, the movable table 2 is used to transmit the above-mentioned sensor signals and the like.
Each sensor signal and the like therein is input to the transmission unit 6, and is output from the transmission unit 6 by infrared rays for, for example, 10 ms. The output sensor signal and the like are received by the receiving unit 8 provided in the device 7 facing the movable table 2. The sensor signals and the like received by the receiving unit 8 are received by the receiving unit 8
Is not output to the device 7 and is stored by the memory.

Next, the state of each sensor in the movable table 2 is output again from the transmitter 8 for, for example, 10 ms. Then, the receiving unit 8 receives this and compares it with the signal stored in the memory. When the compared signals are the same, the receiving section 8 outputs the signals to the device 7, and informs the device 7 that the output signals are the current state of the movable table 2.

The above process is shown in FIG. The first data transmitted as in this process is stored in the memory without being output after being received by the receiving unit 8.

Then, the second data is received, and this data is compared with the data stored in the memory. When the compared data are the same, the data is output, and when they are not the same, the data is not output. In this way, the receiving unit 8 detects two times of data as one cycle, and the receiving unit 8 does not output the data to the device 7 until the detection signals of the two data of one cycle match. In the device 7, it is possible to prevent erroneous detection of the optical signal from the transmitter 6, and it is possible to improve the reliability of driving the transport device.

As described above, according to this embodiment, optical communication is used as a means for transmitting each sensor signal in the movable table to the opposing device, so that it is not necessary to use a cable or the like as compared with the conventional device. Therefore, there is no adverse effect due to noise and the like, and there is no disconnection failure of the cable, so reliability is improved.

Further, since the communication line used conventionally is not used, if the communication line is used as a power supply line, it becomes possible to use a motor or the like on the movable table.

[Effects of the Invention] As described above, according to the present invention, the movable table is provided with a transmitter for transmitting an optical signal, and a receiver for receiving an optical signal from the transmitter is provided at a position facing the transmitter. Is provided in the relative device, the transmitter transmits each sensor signal for monitoring the operation of the movable table as an optical signal, and the receiver receives two optical signals from the transmitter.
At least one cycle is received, and the matched signal is output to the relative device only when the two signals in each cycle match. Therefore, there is no interference due to noise, disconnection, etc. It is possible to accurately transmit the sensor signal of each sensor that monitors the movement of the movable table, which changes dynamically, to the device that faces the movable table, thereby improving the reliability of the movement monitoring of the movable table.

Further, since the optical communication eliminates the wiring, the wiring can be simplified and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a carrier device for explaining an embodiment of the device of the present invention, and FIG. 2 is a flow chart for explaining an optical communication operation of the device of the present invention. 2 ... movable table, 6 ... receiver, 8 ... receiver.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 61-166038 (JP, A) JP 60-63925 (JP, A) JP 59-118561 (JP, A) JP 58- 161340 (JP, A)

Claims (1)

[Claims] 1. A transport device for moving a movable table for mounting a transported object by a drive mechanism to transport the transported object to a relative device facing the movable table, and transmitting an optical signal to the movable table. In addition to providing a transmitter for receiving the optical signal from the transmitter at a position facing the transmitter, the transmitter is provided with a sensor signal for monitoring the operation of the movable table. Is transmitted as an optical signal, and the receiver receives 2 signals from the transmitter.
A carrier device, which receives at least one cycle of one optical signal as one cycle, and outputs the matched signal to the relative device only when two signals of each cycle match.