JP2006108214A - Method for automatic transportation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem caused by a conventional transporting system that transporting and keeping devices require certain degrees of sizes and an an operational loss is generated due to waiting for transportation, while the system decides a device to be treated when a semiconductor wafer is warehoused and performs transportation by instructing a transporting and keeping device, which can transport the wafer to the device in a process, to transport the wafer to the device. <P>SOLUTION: In order to solve the problem, the transporting system adopts such a system that transports the semiconductor wafer to the device at the actually requiring timing of the device by acquiring states of individual devices and semiconductor wafers. Consequently, the number of products to be held in a bay can be reduced to the minimum, and as a result, a product keeping place can be provided in the ceiling space of the bay, and the floor occupying space in the bay which has been the problem for constituting a conventional technique can be reduced significantly. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to product conveyance in a production line, and more particularly, to an automatic conveyance method for a semiconductor wafer production line that requires many processing steps.

The semiconductor wafer production line has a very large number of processing steps, such as several hundred processes, and the number of production devices to be managed may reach several hundred in the case of mass production. Accordingly, in order to produce semiconductor wafers (in the case of lots composed of a plurality of semiconductor wafers, they are also simply referred to as semiconductor wafers in this specification), a means for transferring from the apparatus to the apparatus is required. Is required to be as short as possible in the production of semiconductor wafers. As a transport method for shortening the transport time, there is a conventional technique as disclosed in Patent Document 1.
Japanese Patent Laid-Open No. 11-334810

  However, the following problems occur in the transfer control of the semiconductor wafer by the method shown in the prior art. In the prior art, when the semiconductor wafer A is received after the processing of the semiconductor wafer A, the apparatus X to be processed next is determined, and a transfer instruction is given to the transfer storage apparatus capable of transferring in-process to the apparatus. Yes.

  However, in this method, in consideration of the fact that semiconductor wafers exceeding the capacity of the apparatus are supplied to the apparatus X, a certain size of the transport storage apparatus is required. Also, even if there is sufficient capacity, if a device X cannot be processed due to a mechanical failure, etc., if another device that can be processed is installed in a different bay, There is a problem that operation loss occurs due to waiting for transport.

  Therefore, the present invention can minimize the number of products to be held in the bay by acquiring the status of individual devices and semiconductor wafers and actually transporting the devices at the timing when the devices need them. As a result, an object of the present invention is to provide an automatic conveyance system that can significantly reduce the floor occupation space in the bay.

  In order to achieve this object, the transport system of the present invention has a structure in which a product storage shelf for storing products is suspended from the ceiling, and the storage shelf is connected to a semiconductor manufacturing apparatus and an inspection apparatus. It has a configuration that controls the equipment, and the production progress department that manages and controls the entire current production status, the inventory management recording department that registers the location data of the semiconductor wafer, and the priority order of the semiconductor wafer from the current in-process status A lot dispatch unit having a function to determine, a transfer control unit that transmits a transfer instruction of a semiconductor wafer to a transfer device based on an instruction of the lot dispatch unit, a transfer management recording unit that registers various information about storage shelves, and each transfer Transport equipment information collection unit that monitors and collects the current status of equipment and storage shelves, transport equipment and functions for transporting semiconductor wafers between storage shelves It consists of. When the semiconductor wafer to be transferred to the target device is determined by the lot dispatch unit, the semiconductor wafer is transferred to the transfer device registered in the transfer management recording unit with respect to the target device.

  As described above, the present invention acquires the status of individual devices and semiconductor wafers, and minimizes the number of products to be held in the bay by actually transporting the semiconductor wafers at the timing when the devices need them. As a result, the product storage place can be provided in the ceiling space in the bay, and the floor occupation space in the bay, which has been a problem in the configuration of the prior art, can be greatly reduced.

  In addition, the time of each apparatus such as the current process and the next process, and the state of the semiconductor wafer are acquired, and the apparatus is actually transported at a timing when the semiconductor wafer is required, thereby reducing the transport time.

  A conveyance system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall block diagram of a transport system according to an embodiment of the present invention. This system consists of a production progress unit 1 that manages and controls the entire current production status, a stock management recording unit 2 that stores data such as the location and progress status of semiconductor wafers, and the current status of semiconductor wafers. A lot dispatch unit 3 having a function for determining priority, a transfer control unit 4 for transmitting a transfer instruction of a semiconductor wafer to a transfer device based on an instruction from the lot dispatch unit 3, and a transfer in which various information relating to a storage shelf is registered. Management recording unit 5, transport device 7 and transport device information collecting unit 6 for monitoring and collecting the current state of storage shelves 8A and 8B, transport device 7 and apparatus having a function of transporting semiconductor wafers between storage shelves 8A and 8B It is composed of nine.

  There are two types of storage shelves: a storage shelf 8A in front of the device placed on the ceiling in front of the device, and a storage shelf 8B that is prepared for standby in the transport system.

  In the embodiment of the present invention, any device other than that shown in FIG. 1 may be used as long as it is a transfer device that satisfies the purpose of transferring a semiconductor wafer between apparatuses.

  As shown in FIG. 2, the minimum configuration of the inventory management recording unit 2 includes the name of the semiconductor wafer and the current location of the semiconductor wafer. As long as the name of the semiconductor wafer is unique within the transfer system, any name may be used. In addition, the current location is changed to the storage shelf inventory by the transfer control unit 4 when the transfer device information collecting unit 6 detects that the semiconductor wafer has been received in the storage shelf, and is also output from the storage shelf. When the conveyance device information collection unit 6 detects the change, it is changed by the conveyance control unit 4 during conveyance. Note that the data structure is the minimum structure, and other information may be recorded.

  Moreover, the structure of the conveyance management recording part 5 consists of two parts of FIG. 3, FIG. In FIG. 3, the name includes the name of the storage shelf, the physical stock upper limit of the storage shelf, the current stock, and the alternative transport destination. When the transport device information collection unit 6 detects the delivery from the storage shelf, the current inventory decreases by one unit under the control of the transport control unit 4, and when the storage device is detected, the numerical value increases by one unit under the control of the transport control unit 4. . As long as the name of the storage shelf is a unique name in the transport system, any name may be used. In FIG. 4, each device includes a storage shelf to be used, a stock upper limit that can be stocked in the storage shelf, and a current stock. Also for this current stock, when the transport device information collecting unit 6 detects the delivery from the storage shelf, the numerical value is decreased by one unit by the control of the transport control unit 4, and when receiving is detected, the numerical value is decreased by one unit by the control of the transport control unit 4 To increase. Note that the data structure is the minimum structure, and other information may be recorded.

  Next, configuration examples of the storage shelf 8A and the storage shelf 8B will be described with reference to FIGS. As shown in FIG. 5 and FIG. 6, the storage shelf is composed of a rail 7 </ b> A connecting between the devices and a plurality of carts 7 </ b> B having a function of holding and transporting a case 10 for storing semiconductor wafers. Further, as shown in FIG. 6, the case 10 has a configuration in which an arm attached to the carriage 7 </ b> B is used to enter and exit the apparatus and each storage shelf.

  Next, the flow of processing at the time when processing in a certain process is completed on a certain semiconductor wafer will be described with reference to the flowchart of FIG. When the semiconductor wafer is stored in the standby storage shelf 8B at the end of the processing (step S101 in FIG. 7), the transfer control unit 4 confirms the stock status of the standby storage shelf 8B received from the transfer management recording unit 5 (S102). . If it is determined that the received standby storage shelf 8B has an empty space (S103), the received semiconductor wafer remains in the received standby storage shelf 8B (S104). If it is determined that there is no space in the standby storage shelf 8B, a search is made for an alternative stock standby storage shelf for the standby storage shelf 8B that has been received (S105), and the transfer device 7 is caused to transfer to that shelf. An instruction is issued (S106).

  Now, each device has an upper limit on the number of semiconductor wafers that can be stored in the corresponding pre-device storage shelf 8A and can be processed by the device itself. The upper limit value is set in the transport management recording unit 5 as (1) a method in which a person registers via the terminal 11 connected to the transport control unit 4 as shown in FIG. A method of proportionally allocating the number of available stocks (the number of shelves) by the maximum processable number of devices that use the same storage shelf, The method like this can be considered. Among these, the method (2) and the method (3) will be described in detail below.

  In the method (2) and method (3), the equipment information recording unit 12 is added to the configuration of the transport system as shown in FIG. In order to realize the method (2), the equipment information recording unit 12 is configured as shown in FIG. 10 including the device name and the maximum processable number. When the physical inventory number of the storage shelf X corresponding to the facility i is Sx and the maximum processable number of each device j belonging to the storage shelf X is Mj, the upper limit value Ui is obtained by (Equation 1).

Ui = Sx × Mi / ΣMj (Equation 1)
Here, Σ is the sum of Mj of all devices belonging to the storage shelf X. Specifically, as shown in the flowchart of FIG. 11, the storage shelf X is taken out from the equipment i from the transport management recording unit 5 (step S201 in FIG. 11), and the physical inventory quantity Sx of the storage shelf X is taken out (S202). On the other hand, a list of devices belonging to the storage shelf X is extracted from the transport management recording unit 5 (S203, S204, S205, S211), and the maximum number that can be processed is extracted from the equipment information recording unit 12 (S207) and summed (S208). Finally, calculation is performed according to (Equation 1) (S209, 210, 212).

  Further, for the method (3), the equipment information recording unit 12 is configured as shown in FIG. 12 including the device name and the processing time of one processing unit. When the physical inventory quantity of the storage shelf X corresponding to the facility i is Sx and the processing time of one processing unit of each device j belonging to the storage shelf X is Tj, the upper limit value Ui of the facility i is obtained by (Equation 2). .

Ui = Sx × (1 / Ti) / Σ (1 / Tj) (Expression 2)
Here, Σ is the sum of 1 / Tj of all devices belonging to the storage shelf X. Specifically, as shown in the flowchart of FIG. 13, the storage shelf X is taken out from the equipment i from the transport management recording unit 5 (step S301 in FIG. 13), and the physical inventory quantity Sx of the storage shelf X is taken out (S302). On the other hand, the list of devices belonging to the storage shelf X is extracted from the transport management recording unit 5 (S303, S304, S305, S311), and the processing time of one processing unit is extracted from the equipment information recording unit 12 (S307) and the reciprocal sum is obtained. (S308). Finally, calculation is performed according to (Equation 2) (S309, S310, S312).

  Next, how the semiconductor wafer is transferred by each apparatus will be described with reference to the flowchart of FIG. The transport management unit 4 periodically checks the upper limit value and the current value stored in the transport management recording unit 5 for each device (steps S401, S402, S403, and S409 in FIG. 14) (S404). An inquiry is made to the lot dispatch unit 3 to search for a semiconductor wafer to be transferred next (S 406) with respect to the apparatus (S 405) that is not more than the upper limit value. The lot dispatch unit 3 refers to the inventory management recording unit 2 to determine a semiconductor wafer to be transported, and returns the semiconductor wafer name to the transport management unit 4 (S407). The transfer control unit 4 confirms the current location from the location information of the semiconductor wafer shown in FIG. 2 registered in the inventory management recording unit 2 for the semiconductor wafer name instructed by the lot dispatch unit 3, The front storage shelf 8A corresponding to the device is retrieved from the transport management recording unit 5 and instructed to be transported (S408). In FIG. 14, as a method of periodically checking, a method of automatically inquiring all the devices at regular time intervals is taken, but in addition to the timing when the current value of the inventory in the pre-device storage shelf 8A decreases. It is possible to take a method such as checking for each device, or to combine a plurality of these means.

  The transfer system of the present invention has a feature that a semiconductor wafer can be transferred to a required apparatus at a required timing, and is effective as a transfer system that realizes optimal transfer in semiconductor manufacturing. It can also be applied to other production lines.

Block diagram in an embodiment of the present invention Diagram showing the structure of the inventory management recording unit Diagram showing the configuration of the transport management recording unit Diagram showing the configuration of the transport management recording unit The figure which shows the composition of the conveyance equipment, the storage shelf in front of the device and the standby storage shelf The figure which shows the method of loading / unloading the semiconductor wafer to / from the storage shelf in front of the equipment The figure which shows the conveyance control flow at the time of semiconductor wafer warehousing Diagram showing the configuration for setting the stock upper limit Block diagram in an embodiment of the present invention Diagram showing the configuration of the equipment information recording unit The figure which shows the flow of the setting procedure in the setting method of the stock upper limit Diagram showing the configuration of the equipment information recording unit The figure which shows the flow of the setting procedure in the setting method of the stock upper limit The figure which shows the semiconductor wafer search flow which can be conveyed to the device which can be conveyed

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Production progress part 2 Inventory management recording part 3 Lot dispatch part 4 Conveyance control part 5 Conveyance management recording part 6 Conveyance equipment information collection part 7 Conveyance equipment 7A Rail 7B Carriage 8A Storage shelf 8B Storage shelf 9 Apparatus 10 Case 11 Terminal 12 Equipment information Recording section

Claims (4)

In an automatic transfer method comprising a production progress process, an inventory management recording process, a lot dispatch process, a transfer control process, a transfer management recording process, a transfer device information collecting process, a transfer device and a storage shelf,
An automatic conveying method characterized by having a function of conveying an optimum product that can be automatically processed by the apparatus from the inventory status of the product of each apparatus. The conveyance control process has a function of monitoring a shelf inventory status for each apparatus based on information of a conveyance device information collection process, and having a function of inquiring about a product to be conveyed to a lot dispatch process when a vacancy occurs. The automatic conveying method according to claim 1. 2. The conveyance control process according to claim 1, wherein the determination of empty inventory is performed by comparing an inventory upper limit value set for each semiconductor manufacturing facility and semiconductor inspection facility with the shelf inventory status. Automatic conveyance method. 2. The automatic transfer method according to claim 1, wherein the transfer control step has a function of determining a semiconductor wafer to be transferred based on an inquiry result of the lot dispatch step and issuing an instruction to a transfer device.

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