JPH0664706A - Condition detector and storage device - Google Patents

Abstract

(57) [Abstract] [Purpose] A simple configuration is required to detect the presence / absence of a carrier in the stocker of the wafer carrier and the state of the movable part of the transfer system by the sensor and transmit the detection signal to the control part. Reduce the amount of wiring. [Configuration] For example, in a carrier stocker, sensors S1 to S8 for detecting the presence or absence of a carrier and an interface board 2 are provided for each shelf. The interface board 2 has a parallel signal path 31 and an address signal path 32.
And a bus driver 4 for receiving the detection signals from the sensors S1 to S8 and outputting them to the parallel signal path 31, and the bus driver 4 of the interface board 2 based on the address signal from the address signal path 32. Is provided, and the interface boards 2 are connected to each other to form a bus line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a state detecting device for detecting the position of a movable part with a sensor, and an accommodating device for detecting the presence or absence of a carrier (container) of a semiconductor wafer by the sensor. .

[0002]

2. Description of the Related Art Generally, in many cases, the system is controlled by detecting the position of a movable portion or the presence or absence of an object. For example, in a semiconductor wafer manufacturing process, a carrier system for accommodating and transporting a wafer in a carrier (container) and a wafer for carrying in and out between stations such as a heat treatment station, an exposure / development station, and an inspection station. A carry-in / carry-out port and a carrier stocker, which also plays a role of a buffer, are installed in order to cope with a difference in processing time between stations.

In such a system for transferring a semiconductor wafer, the movement of the transfer system is complicated, such as taking out a wafer from a carrier, holding and moving a plurality of carriers at once, or pushing up a wafer in the carrier. . When carrying out such a transfer, it is necessary to detect the state of the movable part such as the position of the arm or the height position of the wafer push-up mechanism, or the presence or absence of a carrier on each shelf of the stocker. Because, in addition to controlling the timing of the operation of each part, for example, the carrier is moved before the wafer push-up mechanism is lowered,
Alternatively, when the carrier is placed on the shelf of the stocker, if the carrier is present at that position, it may lead to destruction of the wafer or the movable part. Therefore, it is necessary to detect the state and apply the interlock.

Therefore, for each shelf of the stocker, a sensor corresponding to the number of stored carriers is provided to detect the presence or absence of carriers, and the arm position (X, Y, Z directions) is set for each movable unit. The sensor is arranged so as to detect the position) and the like, and a signal line is routed from each sensor to be connected to the control unit so that the detection signal from the sensor is taken into the control unit.

[0005]

However, in the configuration in which the signal line is routed from each sensor and connected to the control section as described above, the wiring amount is large and the wafer transfer system is complicated, so that the sensor of the movable section is Since the number of sensors is large and the storage capacity of the stocker is also large in response to the high throughput, the number of sensors in the stocker is also large, and accordingly, the bundle of signal lines swells considerably. On the other hand, the wafer transfer system is crowded with moving parts and transfer paths, and also has a ventilation mechanism to prevent dust generation. To secure
Alternatively, there is a problem that the wiring length is considerably lengthened by avoiding the mechanical portion and diverted to a long distance, and the wiring amount further increases accordingly. Further, when the sensor and the control unit are considerably separated from each other, noise is easily picked up and there is a problem in control stability.

The present invention has been made under such circumstances, and an object thereof is to greatly reduce the wiring amount for connecting the control unit and the sensor without using a complicated circuit. An object of the present invention is to provide a state detection device and a storage device capable of performing.

[0007]

According to a first aspect of the present invention, a sensor is provided for each unit to be detected to detect the state of each of a plurality of objects to be detected, and a detection signal of each sensor is fetched into a control unit. In the state detection device, for each detected unit, an interface board having a parallel signal path and an address signal path is provided, the input side is connected to the output side of the sensor, and the output side is connected to the parallel signal path, respectively.
A bus driver for outputting the detection signal of each sensor to a parallel signal path, and sent via the address signal path,
When an address signal assigned to the detected unit is input, an address selection circuit that drives the bus drive unit of the interface board related to the detected unit and outputs the detection signal of each sensor to the parallel signal path And the parallel signal paths and the address signal paths of each interface board are connected to each other to form a bus line which is a transmission path to the control unit.

According to a second aspect of the present invention, a plurality of storage units are provided in which a plurality of stored objects are arranged and stored, and each storage unit is provided with a sensor for detecting the presence or absence of the plurality of stored objects. In the storage device that captures the detection signal of each sensor in the control unit, an interface board having a parallel signal path and an address signal path is provided for each storage unit, and the input side is the output side of the sensor and the output side is the A bus driver connected to each of the parallel signal paths to output the detection signal of each sensor to the parallel signal path;
Based on the address signal assigned to the storage unit sent through the address signal path, the bus drive section of the interface board related to the storage unit is driven to output the detection signal of each sensor to the parallel signal path. Provided with the address selection circuit on the interface board,
The parallel signal paths and the address signal paths of each interface board are connected to each other to form a bus line which is a transmission path to the control unit.

According to a third aspect of the present invention,
A plurality of sensors for respectively detecting the states of a plurality of detected objects are provided, and in a state detection device that takes the detection signal of this sensor into the control unit, a first interface board is provided for each detected unit, A second interface board having a bus line including a parallel signal path and an address signal path, which is common to the detected units and is connected to the control unit, is provided, and the detection signal of the sensor is transmitted to the bus. A parallel signal line is connected between the first interface board and the bus line of the second interface board, the input side is connected to the output side of the sensor, and the output side is connected to the parallel signal line. The first interface board is provided with a bus driver for outputting the detection signal of the Based on the address signal assigned to the unit to be inspected sent through the line, the bus driving unit of the first interface board related to the unit to be inspected is driven to parallelize the detection signals of the respective sensors. It is characterized in that an address selection circuit for outputting to the signal line is provided.

[0010]

In the case where the unit to be detected is a storage unit in which a plurality of objects to be stored are arranged and stored, for example, as in the invention of claim 2, an address signal is output from the control unit through the bus line. By doing so, the storage unit corresponding to the address signal, for example, the bus drive unit of the interface board related to the storage rack is driven, the signal line of each sensor of the storage rack is connected to the bus, and the detection signal from each sensor is transmitted. Captured by the control unit.

Further, in the invention of claim 3, when the address signal is output from the control section through the bus line, for example, when the address selection circuit is arranged on the second interface board, the address signal is changed from here to the address signal. An enable signal is issued to the bus driving section of the first interface board of the corresponding detected unit to drive the bus driving section, whereby each sensor of the detected unit outputs the first interface board and the second interface board. Is transmitted to the control unit via the interface board.

Therefore, by forming a bus line of a predetermined number of bits, the detection signal from each sensor is taken into the control section by selecting the interface board, and the wiring amount is reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the state detecting device according to the present invention is applied to an accommodating device for accommodating carriers for semiconductor wafers will be described below. FIG. 1 shows an accommodating device for carriers (usually called a "carrier stocker"). It is a figure which shows a part of transfer station of the wafer containing.

This transfer station is a station for taking out a wafer from a carrier carried from the outside and carrying it into a heat treatment furnace, and also for carrying a wafer after heat treatment into a carrier and carrying it out. For example, a plurality of shelves capable of accommodating, for example, eight carriers 11 each containing a wafer are arranged in a stack, and a stocker 1 having an input / output port 10 at the bottom, and this stocker 1
The carriers 11 arranged on each of the shelves are collectively transported,
A transport mechanism 12 that can move in the X, Y, and Z directions, a carrier liner 13 that stops in front of the bottom shelf of the stocker 1 and that can move in the Y direction, and this carrier liner 13 is located in front of the stocker 1. To the wafer boat (not shown) while holding the unprocessed wafer W in the carrier 11 when the wafer W is stopped at a predetermined position apart from the Y direction in the Y direction, and vice versa. And the carrier liner 1
A wafer counter 15 which is arranged directly below the transfer path 3 and pushes up the wafer W in the carrier 11 to count the number of wafers W, operates in the same manner as the wafer counter 15, and aligns the wafer orientation flat. And a flat finder 16 for

In the transfer station having such a structure,
Carriers are sequentially carried from the outside to the input / output port 10, and these carriers are transferred to the stocker 1 by a feeding mechanism (not shown).
Is captured in the bottom row of. Then, these carriers are collectively stored in a predetermined shelf of the stocker 1 by the transport mechanism 12, and then the carrier 11 is loaded from each shelf into the carrier liner 1.
Hand over to 3. Next, after the carrier liner 13 has moved to a predetermined position, the wafer W in the carrier 11 is taken out by the gripping mechanism 14 and transferred to a wafer boat (not shown).

Next, the stocker 1 which is the main part of this embodiment
2, the number of the sensors S1 corresponding to the number of the carriers 11 on each shelf of the stocker 1 as shown in FIG. ~ S8 are arranged. The sensors S1 to S8 are, for example, light reflection type sensors,
Various types such as limit switches can be used.

Further, the signal lines of the sensors S1 to S8 are connected to the respective shelves, and the interface boards 2 for converting the detection signals (output signals) of the sensors S1 to S8 into logical signals and transmitting them to the control section 100 are provided on the shelves. , And the interface boards 2 are connected in cascade (cascade connection) with each other to form a bus line which is a transmission path to the control unit 100.

The interface board 2 will be described with reference to FIG. 3. The interface board 2 is provided with a parallel signal path 31 composed of 8-bit signal paths corresponding to the number of sensors S1 to S8 and assigned to each shelf. And an address signal path 32 formed of, for example, a 4-bit signal path for transmitting an address signal, and a connector 3A and a connector 3B are provided at upper and lower ends of a signal path group including the parallel signal path 31 and the address signal path 32, respectively. Are connected.

Since the connectors 3A and 3B having the same upper and lower structures are vertically symmetrically attached, a portion of the interface board 2 including the parallel signal path 31 and the address signal path 32 and the connectors 3A and 3B (as will be described later). This part is part of the bus line) has a vertically symmetrical structure.

The interface board 2 is provided with an insulation circuit 41, a bus driver (bus driver) 4 and an address selection circuit 5. The insulation circuit 41 has an input side connected to the signal lines from the sensors S1 to S8. In addition, the output side is connected to the input side of the bus driver 4. The output side of the bus driver 4 is connected to the parallel signal path 31, and the sensor S supplied through the insulating circuit 41 by the input of the enable signal from the address selection circuit 5
The detection signals 1 to S8 are output to the 8-bit signal path of the parallel signal path 31, respectively.

The input side of the address selection circuit 5 is connected to the address signal path 32, and when the address signal given through the address signal path 32 corresponds to the interface board 2, that is, the sensors S1 to S8 are arranged. It is configured to output an enable signal to the bus driver 4 when it corresponds to the address assigned to the existing shelf.

FIG. 4 is a diagram showing an example of a concrete circuit configuration of each part provided on the interface board 2. The insulating circuit 41 is provided with, for example, photo couplers F1 to F1 provided corresponding to the sensors S1 to S8, respectively. F8, and the signal lines from the sensors S1 to S8 are connected across the light emitting diodes of the photocouplers F1 to F8. The bus driver 4 is composed of, for example, three-state logic circuits T1 to T8, the input sides of which are connected to the phototransistor sides of the photocouplers F1 to F8, and the output sides of the parallel signal paths 31 are 8-bit signal paths. It is connected to the. A voltage + V is applied to the collector side of the phototransistor via resistors R1 to R8, respectively.

The address selection circuit 5 comprises, for example, a logic circuit unit whose input side is connected to predetermined two signal paths of the 4-bit signal path of the address signal path 32, and the address signal corresponding to the interface board 2 is selected. Three-state logic circuit T of the bus driver 4 at the time of input
It has a function of outputting an enable signal to 1 to T8.

In the interface board 2 having such a structure, the connector 3A on the upper side of the interface board 2 of a certain shelf and the connector 3B on the lower side of the interface board 2 of the shelf one level higher than the shelf are connected to the flat cable 30. A bus line is formed by connecting the parallel signal paths 31 and the address signal paths 32 of the interface board 2 in a cascade connection with each other.
One end of this bus line is connected to the control unit 100 (see FIGS. 2 and 3) that controls the system according to the present embodiment. Actually, the bus line includes a power supply voltage line, an earth line, etc., but they are described in detail in the description.

Next, the operation of the above embodiment will be described. First, in the transfer system shown in FIG. 1, as described above, the carrier 11 accommodating unprocessed wafers from the outside is the stocker 1
It is once stored in the container and is conveyed from there through a carrier liner 13 and the like to a heat treatment section (not shown).

The presence or absence of the carrier 11 is constantly detected by the sensors S1 to S8 arranged on each shelf of the stocker 1, and the detection signals are input to the photocouplers F1 to F8 of the interface board 2, respectively, and output from the bus side. It is input to each of the three-state logic circuits T1 to T8 of the drive unit 4. On the other hand, the control unit 100 sequentially outputs address signals via the bus to the address selection circuit 5 on the interface board 2 side.
When the address signal assigned to (the shelf) is fetched, the address selecting circuit 5 outputs an enable signal to the bus driving unit 4 to drive the bus driving unit 4, thereby detecting signals of the sensors S1 to S8. The parallel signal path 31
To transmit. Therefore, the detection signal is taken into the control unit 100, and the detection signal is used for displaying the state of each shelf of the stocker 1 or controlling the transport mechanism 12.

According to this embodiment, the interface boards 2 of the shelves are connected to each other to form a bus line, and the detection signals of the sensors S1 to S8 of the shelves are sequentially sent to the control unit 100 through the bus line. Since the transmission is performed, the wiring amount can be significantly reduced as compared with the case where a swelled bundle of signal lines from all the sensors of the stocker 1 is routed to the control unit 100. It's a good idea, and it also resists noise.

As a method of reducing the wiring amount, if the detection signal of the sensor is serially transmitted, the control software is complicated and a dedicated control circuit must be incorporated in each interface board 2, so that a hardware configuration is required. However, since the parallel transmission is adopted in the above-described embodiment, the control software and the hardware configuration are simple.

Furthermore, since the connectors 3A and 3B are provided symmetrically with respect to each interface board 2, the interface board 2 is attached to the left side surface and the right side surface of the stocker 1 for the convenience of the factory layout. In any case, there is an advantage that the interface board 2 can be applied to either type by mounting the interface board 2 upside down.

In the above, the present invention can be applied not only to the stocker of the carrier which is a container of the wafer but also to an apparatus for accommodating another object to be accommodated, and further not limited to the accommodating apparatus, and it can be applied to an object to be accommodated. It can also be applied to an apparatus in which a plurality of sensors are provided for each detection unit and the state of the detected object related to the detected unit is detected by these sensors. In the above-described embodiment, each shelf of the stocker 1 corresponds to a unit to be detected or a unit to be stored, and the carrier 1
Reference numeral 1 corresponds to an object to be detected or an object to be stored.

Next, another embodiment of the present invention will be described with reference to FIG. 5. In this embodiment, the states of a plurality of detected objects are detected for each of the plurality of detected units U1 to Un. A sensor S (denoted by the same reference numeral for convenience of description) and a first interface board 6 are provided, and a second interface board 7 common to the units U1 to Un is provided.

The first interface board 6 is
Isolation circuit 61, logic switching circuit 9, and bus driver 62
And is configured to output a detection signal from each sensor S related to the corresponding unit to be detected to the bus driver 62 via the insulating circuit 61 and the logic switching circuit 9. On the other hand, one end of the second interface board 7 has the control unit 1
For example, an 8-bit parallel signal path 7 connected to 00
A bus line consisting of 1 and 4-bit address signal paths 72 is provided, and the parallel signal path 71 and the first
The bus driver 62 of each interface board 6 is connected by, for example, an 8-bit parallel signal line 63.

An address selection circuit 8 composed of, for example, a logic circuit unit is connected to the address signal path 72 of the second interface board 7, and the address selection circuit 8 is inputted through the address signal path 72. The bus driver 62 of the unit (first interface board 6) corresponding to the address signal is configured to output an enable signal via the enable signal line 81 to drive the bus driver 62. Note that reference numerals 64, 73 and 82 in FIG. 5 denote connectors.

FIG. 6 is a diagram showing an example of a specific circuit of the first interface board 6, in which the enable signal of the bus driver 62 is input from the second interface board 7, and the insulating circuit 61 and the bus. The circuit configuration is the same as that of the interface board 2 described in the previous embodiment (see FIG. 4) except that the logic switching circuit 9 is provided between the drive unit 62 and the drive unit 62.

The logic switching circuit 9 includes exclusive OR circuits EX1 to EX8 in the detection signal lines of the respective sensors S, respectively.
, One of the input terminals of the exclusive OR circuits EX1 to EX8 is connected to the output sides of the photocouplers F1 to F8, and the output terminals thereof are connected to the input sides of the three-state logic circuits T1 to T8, respectively. Further, exclusive OR circuits EX1 to EX8
Switches SW1 to SW8 for switching logic inputs are connected to the other input ends of the switches. The switches SW1 to SW8 are connected between a + V voltage source (voltage supplied from the control unit 100) and ground, and are configured to switch the logic of the inputs at one ends of the exclusive OR circuits EX1 to EX8. Has been done.

Here, regarding the unit to be detected shown in FIG. 5, for example, the transfer mechanism 1 in the transfer system shown in FIG.
2, the carrier liner 13, the wafer gripping mechanism 14, the wafer counter 15, the flat finder 16 and the like correspond to each unit, and the position detecting sensors of these movable parts, for example, in the X, Y and Z directions are the sensors in the unit. Equivalent to S.

Next, the operation of this embodiment will be described. The state of each unit is detected by the sensor S of each unit U1 to Un. The state of the unit is, for example, whether or not the wafer gripping mechanism is gripping the wafer, whether or not the wafer is above the carrier liner 13, and the detection signal from the sensor S is detected by the insulating circuit 61 and the logic switching circuit 9. It is input to the bus driver 62 via the.

On the other hand, from the control unit 100 to the address signal path 72
The address selection circuit 8 of the second interface board 7 sends an enable signal to the first interface board 6 of the unit corresponding to the address signal, whereby the bus of the interface board 6 concerned is transmitted. The drive unit 62 is driven so that the detection signal on the input side of the bus drive unit 62 becomes
Is output to the parallel signal path 71 via the
Be transmitted to. The control unit 100 performs control such as interlocking the movable portion based on this detection signal.

In this embodiment, since the detection signal of the sensor is transmitted to the control unit 100 by being carried on the bus line via the two interface boards 6 and 7, the wiring amount can be reduced. In this case the second interface board 7
The effect is further enhanced by placing the terminal on the terminal side as much as possible. When the units are separated from each other, if the second interface board 7 is arranged in the middle of the unit group, the first interface boards 6 are connected to each other by a flat cable as in the previous embodiment and the bus is connected. The amount of wiring is reduced as compared with the case where lines are formed.

Since the logic switching circuit 9 is provided on the first interface board 6, no matter whether the normally open sensor or the normally closed sensor is used, depending on the state of the switch SW, the control section 100 can The logic (“1”, “0”) of the detected detection signals can be unified, and the same interlock can be applied to the units. It can also be applied to wiring checks and troubleshooting. Opening / closing the switch SW may indicate a sensor defect or interface board 6
It is possible to check whether or not there is a defect such as a subsequent disconnection. Such a logic switching circuit 9 may be incorporated in the interface board 2 of the previous embodiment.

Further, in the embodiment shown in FIG. 5,
Address selection circuit 8 on the second interface board 7
By providing the second interface board 7
Since it is not necessary to draw the address signal path to the first interface board 6 (in this case, only the enable line is required), the wiring amount can be small, but even if the first interface board 6 is provided with the address selection circuit. Good.

In the above, the hardware configuration of the interface boards 2, 6, and 7 is not limited to the above-mentioned embodiment, and for example, each output line of the three-state logic circuit used in the bus drive section, It is possible to adopt a configuration in which two output lines having mutually different logics are used to make them resistant to noise.

When the present invention is applied to a storage device, the storage units (corresponding to shelves in the embodiment) can be applied side by side instead of being arranged vertically, and the present invention can also be applied to semiconductor wafers. It may be applied to various systems other than the manufacturing process of.

[0044]

According to the inventions of claims 1 and 2, since the bus lines are formed by connecting the interface boards to each other, the signal line from the sensor may be wired to the interface board. Therefore, the amount of wiring is small, and the parallel transmission does not complicate the circuit configuration of the interface board.

According to the invention of claim 3, the signal line from the sensor is connected to the first interface board for each unit, and these first interface boards are commonly connected to the second interface board. , The amount of wiring is small even if the units are widely separated.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of an embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing the carrier stocker of the embodiment shown in FIG.

FIG. 3 is a configuration diagram showing an interface board according to an embodiment of the present invention.

FIG. 4 is a circuit diagram showing an example of a hardware configuration of an interface board.

FIG. 5 is a configuration diagram showing a configuration of another embodiment of the present invention.

6 is a circuit diagram showing a hardware configuration of a first interface board shown in FIG.

[Explanation of symbols]

 1 stocker 11 carrier 2 interface board 31, 71 parallel signal path 32, 72 address signal path 4, 62 bus driver 5, 8 address selection circuit 6 first interface board 7 second interface board U1 to Un

Claims (3)

[Claims] 1. A sensor for detecting the state of each of a plurality of objects to be detected is provided for each unit to be detected, and in a state detection device for incorporating a detection signal of each sensor into a control unit, each unit to be detected. An interface board having a parallel signal path and an address signal path is provided, and the input side is connected to the output side of the sensor and the output side is connected to the parallel signal path, and the detection signal of each sensor is output to the parallel signal path. And the bus drive section of the interface board related to the detected unit when an address signal assigned to the detected unit, which is sent through the address signal path, is input to each sensor. The interface board is provided with an address selection circuit that outputs the detection signal of The state detection device, wherein the parallel signal paths and the address signal paths are connected to each other to form a bus line which is a transmission path between the control section and the parallel signal paths. 2. A plurality of storage units for storing a plurality of articles to be stored are arranged, and a sensor for detecting the presence or absence of each of the plurality of articles to be stored is provided for each storage unit.
In the storage device that takes the detection signal of each sensor into the control unit, an interface board equipped with a parallel signal path and an address signal path is provided for each storage unit, and the input side is the output side of the sensor and the output side is the parallel signal. A bus drive unit for outputting the detection signal of each sensor to a parallel signal path and an address signal assigned to the storage unit, which is sent via the address signal path. The interface board is provided with an address selection circuit that drives the bus drive section of the interface board related to the storage unit and outputs the detection signal of each sensor to the parallel signal path, and the parallel signal paths and the address signal paths of each interface board are connected to each other. Connect to form a bus line that is a transmission line between the controller and Storage device and butterflies. 3. A plurality of sensors for detecting the states of a plurality of objects to be detected are provided for each of the units to be detected. A first interface board is provided for each unit, and a second interface board having a bus line including a parallel signal path and an address signal path, which is common to the detected units and is connected to the control unit, is provided. A parallel signal line is connected between the bus line of the first interface board and the bus line of the second interface board to transmit the detection signal of the sensor to the bus line, and the input side is the output side of the sensor and the output side is also output. Side is connected to the parallel signal lines respectively, and a bus driver for outputting the detection signal of each sensor to the parallel signal lines is provided. No. 1 interface board, and drives the bus drive section of the first interface board of the unit to be inspected based on the address signal assigned to the unit to be inspected, which is sent via the bus line. And a state detection device including an address selection circuit for outputting a detection signal of each sensor to a parallel signal line.