Transport system and transport method

A track in a transport system includes a standby section associated with a certain processing apparatus to allow a transport vehicle to wait. When determining a transport request to transport a FOUP to a load port of the certain processing apparatus exists, the controller allocates, to the transport vehicle, a first transport command to transport the FOUP to the standby section. When reaching the standby section, the transport vehicle waits while holding the FOUP. Subsequently, when determining that the FOUP is transportable to the load port of the certain processing apparatus, the controller allocates, to the transport vehicle, a second transport command to transport the FOUP to the load port of the certain processing apparatus.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a transport system and a transport method.

2. Description of the Related Art

A known example of a transport system applied to a semiconductor fabrication plant includes a track, a plurality of transport vehicles traveling along the track to transport an object to load ports of a plurality of processing apparatuses, and a controller communicating with each of the transport vehicles and controlling the operation of each of the transport vehicles (for example, see Japanese Unexamined Patent Publication No. 2000-339027).

In the transport system as described above, when there exists a transport request to transport an object to a load port in a situation where an object is not transportable to the load port, the controller allocates, to a transport vehicle, a transport command to transport the object to a storage shelf or the like for temporarily storing an object. Subsequently, when the situation changes so that an object is transportable to the load port, the controller allocates, to one of the transport vehicles, a transport command to transport the object to the load port from the storage shelf or the like.

Specifically, when an object temporarily stored in a storage shelf or the like is to be transported from the storage shelf or the like to the load port, the controller detects a transport vehicle that can transport the object and allocates, to the detected transport vehicle, a transport command to transport the object from the storage shelf or the like to the load port. The transport vehicle to which the transport command is allocated picks up the object temporarily stored in the storage shelf or the like, transports the object to the load port, and unloads the object. This operation takes time. There is, therefore, a limit in reducing the time taken to unload the object to a load port after the situation changes so that the object is transportable to the load port.

In particular, when the distance between the storage shelf or the like and the load port is long, the time required for the transport vehicle to pick up the object temporarily stored in the storage shelf or the like, transport the object to the load port, and unload the object is long. As a result, for example, the operating rate may be reduced in a certain processing apparatus, such as a processing apparatus with high processing speed.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide transport systems and transport methods, in which a reduction in an operating rate of a processing apparatus is decreased or prevented.

A transport system according to a preferred embodiment of the present invention includes a track, a plurality of transport vehicles to travel along the track and transport an object to a load port of each of a plurality of processing apparatuses, and a controller configured or programmed to communicate with each of the transport vehicles and control operation of each of the transport vehicles. The track is provided with a standby section associated with a certain one of the plurality of processing apparatuses to allow the transport vehicle to wait. When the controller determines that there exists a transport request to transport the object to a load port of the certain one of the plurality of processing apparatuses, the controller allocates, to the transport vehicle, a first transport command to transport the object to the standby section. When reaching the standby section, the transport vehicle to which the first transport command has been allocated waits in the standby section while holding the object. When the controller determines that the object is transportable to the load port of the certain processing apparatus, after allocating the first transport command to the transport vehicle, the controller allocates, to the transport vehicle to which the first transport command has been allocated, a second transport command to transport the object to the load port of the certain processing apparatus.

In this transport system, even if the object is not transportable to the load port of the certain processing apparatus, the transport vehicle picks up the object and starts travelling toward the standby section associated with the certain processing apparatus. When the situation changes so that the object is transportable to the load port of the certain processing apparatus, the transport vehicle travelling toward the standby section or the transport vehicle reaching the standby section and waiting while holding the object is able to immediately transport the object to the load port of the certain processing apparatus without the need for performing an operation, such as picking-up, again. This configuration decreases or prevents a reduction in an operating rate of the certain processing apparatus.

In a transport system according to a preferred embodiment of the present invention, the transport vehicle may travel along the track in one direction, and the standby section may be connected in parallel with a second travel section continuous to an upstream side of a first travel section including a position to transfer the object to the load port of the certain processing apparatus. This configuration enables the transport vehicle to wait in the standby section without interrupting travel of the transport vehicle from the second travel section to the first travel section.

In a transport system according to a preferred embodiment of the present invention, the first travel section may be provided for a plurality of the certain processing apparatuses. In this configuration, since one standby section is associated with a plurality of certain processing apparatuses, the area of the space necessary to provide the standby section is able to be reduced.

In a transport system according to a preferred embodiment of the present invention, when the controller determines that a standby section-withdrawal condition is satisfied, the controller may allocate, to the transport vehicle to which the first transport command has been allocated, a third transport command to transport the object to a predetermined destination. For example, this configuration is able to prevent the transport vehicle from staying in the standby section due to some error occurring in the certain processing apparatus.

In a transport system according to a preferred embodiment of the present invention, when the controller determines, as the standby section-withdrawal condition, that a predetermined time or longer has elapsed since the transport vehicle to which the first transport command has been allocated reaches the standby section, the controller may allocate the third transport command to the transport vehicle to which the first transport command has been allocated. For example, this configuration is able to prevent the transport vehicle from staying in the standby section due to some error occurring in the certain processing apparatus.

In a transport system according to a preferred embodiment of the present invention, when the controller determines, as the standby section-withdrawal condition, that at least a predetermined number of the transport vehicles are waiting in the standby section, the controller may allocate the third transport command to at least one of the transport vehicles waiting in the standby section. For example, this configuration is able to prevent the transport vehicle from staying in the standby section due to some error occurring in the certain processing apparatus.

In a transport system according to a preferred embodiment of the present invention, the transport vehicle may travel along the track in one direction. When a plurality of the transport vehicles are waiting in the standby section, and a transport command to withdraw from the standby section is allocated to one of the transport vehicles waiting in the standby section, excluding the transport vehicle most downstream, the controller may allocate a transport command to withdraw from the standby section and transport the object to the standby section again, to another transport vehicle downstream from the one of the transport vehicles. When the controller determines, as the standby section-withdrawal condition, that the transport vehicle to which the first transport command has been allocated has withdrawn from the standby section at least a predetermined number of times, the controller may allocate the third transport command to the transport vehicle to which the first transport command has been allocated. For example, this configuration is able to prevent ejection control (control of allowing the downstream transport vehicle to withdraw from the standby section and return to the standby section again in order to withdraw the upstream transport vehicle from the standby section) from being repeated due to some trouble occurring in the certain processing apparatus.

A transport method according to a preferred embodiment of the present invention is performed in a transport system. The transport system includes a track, a plurality of transport vehicles to travel along the track and transport an object to a load port of each of a plurality of processing apparatuses, and a controller configured or programmed to communicate with each of the transport vehicles and control operation of each of the transport vehicles. The track is provided with a standby section associated with a certain one of the plurality of processing apparatuses to allow the transport vehicle to wait. The transport method includes a first step, performed by the controller, of allocating, to the transport vehicle, a first transport command to transport the object to the standby section, when determining that there exists a transport request to transport the object to a load port of the certain processing apparatus; a second step, performed by the transport vehicle to which the first transport command has been allocated, of waiting in the standby section while holding the object, when reaching the standby section; and a third step, performed by the controller, of allocating, to the transport vehicle to which the first transport command has been allocated, a second transport command to transport the object to the load port of the certain processing apparatus, when determining that the object is transportable to the load port of the certain processing apparatus, after allocating the first transport command to the transport vehicle.

This transport method decreases or prevents reduction in an operating rate of the certain processing apparatus, as in the transport system described above.

Preferred embodiments of the present invention decrease or prevent reduction in an operating rate of a certain processing apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described in detail below with reference to the figures. The same or corresponding parts in the figures are denoted by the same reference signs, and an overlapping description will be omitted.

As illustrated inFIG. 1, a transport system1includes a track10, a plurality of transport vehicles20, and a controller50. The track10is preferably provided in the vicinity of a ceiling of a semiconductor fabrication plant equipped with a plurality of processing apparatuses100. The transport vehicle20is an overhead hoist transfer (OHT) and travels on the track10in one direction while being suspended from the track10. The transport vehicle20transports a front opening unified pod (FOUP)90accommodating a plurality of semiconductor wafers as an object to a load port101of each processing apparatus100. The controller50communicates with each transport vehicle20and controls the operation of each transport vehicle20.

The track10includes a plurality of sections10a,10b,10c,10d, and10e. The section10bis linearly connected to the downstream side of the section10a. The section10cis curved to be bent back and connected to the downstream side of the section10b. The section10dis linearly connected to the downstream side of the section10c. The section10ebranches from the connection position between the section10cand the section10dand merges with the connection position between the section10aand the section10b.

In such a track10, the transport vehicle20entering through the upstream side of the section10atravels from the section10ato the section10b, then travels to the section10c, thereafter travels to the section10d, and exits to the downstream side. Alternatively, the transport vehicle20entering through the upstream side of the section10atravels from the section10ato the section10b, then travels to the section10c, thereafter travels from the section10cto the section10e, and travels to the section10bagain. The configuration of the track10is illustrated only by way of example and not limitative.

The section10bis provided with a standby section30associated with certain processing apparatuses100A,100B, and100C, of a plurality of processing apparatuses100, to allow the transport vehicle20to wait. In the standby section30, a plurality of standby points31and32are set, which are positions where the transport vehicle20waits. In the figure, a standby point31set on the most upstream side of the standby section30and four standby points32a,32b,32c, and32dset on the downstream side of the standby point31are illustrated as standby points.

In the section10c, a position is set to transfer a FOUP to the load port101of each of the certain processing apparatuses100A,100B, and100C. Three certain processing apparatuses100A,100B, and100C are disposed along the section10cin this order from the upstream side, and the load ports101of certain processing apparatuses100A,100B, and100C are positioned below the section10c. When a FOUP90is placed onto the load port101, each of the certain processing apparatuses100A,100B, and100C takes in a semiconductor wafer in the FOUP and performs a predetermined process on the semiconductor wafer. Each of the certain processing apparatuses100A,100B, and100C returns the semiconductor wafer subjected to a predetermined process into the FOUP90and sets the FOUP90to a state transportable by the transport vehicle20.

The certain processing apparatuses100A,100B, and100C are devices that perform a process with higher processing speed, among the processing apparatuses100(that is, among the processing apparatuses100, a process that requires a shorter time to perform a predetermined process on a semiconductor wafer and set the FOUP90to a state transportable by the transport vehicle20, after the FOUP90is placed on the load port101). Examples of the certain processing apparatuses100A,100B, and100C include testing devices and lithography devices.

In the section10c, normal processing apparatuses100D and100E are disposed, which are processing apparatuses100other than the certain processing apparatuses100A,100B, and100C. The normal processing apparatuses100D and100E are disposed along the section10cin this order from the upstream side, and the load ports101of the normal processing apparatuses100D and100E are positioned below the section10c. When a FOUP90is placed on the load port101, each of the normal processing apparatuses100D and100E takes in a semiconductor wafer in the FOUP and performs a predetermined process on the semiconductor wafer. Each of the certain processing apparatuses100A,100B, and100C returns the processed semiconductor wafer into the FOUP90and sets the FOUP90to a state transportable by the transport vehicle20. The normal processing apparatuses100D and100E perform a process with lower processing speed than the certain processing apparatuses100A,100B, and100C.

A stocker40is disposed in the vicinity of the connection position between the section10cand the section10d. The stocker40is a facility that temporarily stores a plurality of FOUPs90transported by the transport vehicles20. The stocker includes a port41positioned below the connection position between the section10cand the section10d. When a FOUP90is placed onto the port41, the stocker40takes in the FOUP90and temporarily stores the FOUP90. When the temporarily stored FOUP90is to be obtained by the transport vehicle20, the FOUP90is placed onto the port41and set to a state transportable by the transport vehicle20. For example, a storage shelf to temporarily store an object may be used instead of the stocker40.

The transport vehicle20includes a transfer mechanism to transfer a FOUP90to the load port101. The transfer mechanism includes, for example, a grip to grip a FOUP90and an elevator mechanism to elevate and lower the grip. In this configuration, for example, the transport vehicle20stops at a position to transfer the FOUP90to the load port101of the certain processing apparatus100A, and, in this state, the transfer mechanism operates to transfer the FOUP90to the load port101. The transfer of the FOUP90to the load port101includes a case where the FOUP90held by (loaded on) the transport vehicle20is supplied (unloaded) to the load port101and a case where the transport vehicle20obtains (picks up) the FOUP90placed on the load port101.

The controller50is preferably configured or programmed to include a transport controller50A and a transport vehicle controller50B. The transport controller50A is a higher-level controller for the transport vehicle controller50B. The transport controller50A communicates with the transport vehicle controller50B and a fabrication controller (not illustrated). The fabrication controller communicates with each processing apparatus100and submits to the transport controller50A a transport request to transport a FOUP90to the load port101of each processing apparatus100. When the transport controller50A determines that a transport request exists, the transport vehicle controller50B allocates a transport command corresponding to the transport request to one of the transport vehicles20. The transport controller50A, the transport vehicle controller50B, and the fabrication controller preferably are each, for example, a computer device including a processor, a memory, a storage, and a communication device. In each controller, the processor executes predetermined software (program) read into a memory or the like and controls read and write of data in the memory and the storage and communication between the controllers through the communication device to implement the functions of the controller as described later.

In the transport system1, standby control described below is performed. The standby control performed in the following situation will be described by way of example. As illustrated inFIG. 1, a FOUP90is placed on the load port101of the certain processing apparatus100A, of three certain processing apparatuses100A,100B, and100C disposed along the section10c. Therefore, at this time, the certain processing apparatus100A is not in a situation where the FOUP90is transportable to its load port101. In order to obtain the FOUP90placed on the load port101of the certain processing apparatus100A, the transport vehicle20A is traveling through the section10ctoward the certain processing apparatus100A.

In such a situation, when there exists a transport request to transport another FOUP90to the load port101of the certain processing apparatus100A, the transport controller50A communicates with the fabrication controller to determine that the transport request exists. Here, the transport controller50A creates a first transport command to transport a FOUP90to the standby section30. The transport controller50A then transmits the first transport command to the transport vehicle controller50B. The transport vehicle controller50B receiving the first transport command allocates the first transport command to the transport vehicle20B (first step). Specifically, the first transport command is a command that allows the transport vehicle20B to transport a FOUP90to the standby point31in the standby section30. The figure illustrates a state in which the transport vehicle20B that has been allocated with the first transport command is travelling through the section10awhile holding a FOUP90to be transferred to the load port101of the certain processing apparatus100A. Even when a FOUP90is not placed on the load port101of the certain processing apparatus100A and the certain processing apparatus100A is in a situation where a FOUP90is transportable to its load port101, the transport vehicle controller50B allocates, to the transport vehicle20B, the first transport command to transport a FOUP90to the standby section30.

Subsequently, as illustrated inFIG. 2, the transport vehicle20B reaches the standby point31, and the first transport command is completed. The transport vehicle20B reaching the standby point31waits at the standby point31while holding the FOUP90(second step).

Subsequently, as illustrated inFIG. 3, when the standby point32downstream from the transport vehicle20B is vacant (that is, another transport vehicle20is not waiting) in the standby section30, the transport vehicle controller50B allocates, to the transport vehicle20B, a move command to move to the standby point32on the downstream side. The figure illustrates a state in which the transport vehicle20B, to which the move command to move to the standby point32ahas been allocated by the transport vehicle controller50B, has been moved to the standby point32a. The transport vehicle20B reaching the standby point32awaits at the standby point32awhile holding the FOUP90.

In the figure, the transport vehicle20A has reached a position to transfer a FOUP90to the load port101of the certain processing apparatus100A. The transport vehicle20A obtains the FOUP90placed on the load port101of the certain processing apparatus100A. The certain processing apparatus100A thus enters a state in which the FOUP90is transportable to its load port101.

Subsequently, as illustrated inFIG. 4, the transport controller50A communicates with the fabrication controller to determine that a FOUP90is transportable to the load port101of the certain processing apparatus100A. Here, the transport controller50A creates a second transport command to transport a FOUP90to the load port101of the certain processing apparatus100A. The transport controller50A then transmits the second transport command to the transport vehicle controller50B. The transport vehicle controller50B receiving the second transport command allocates the second transport command to the transport vehicle20B to which the first transport command has been allocated (third step). Subsequently, the transport vehicle20B transports the FOUP90from the standby point32ato the load port101of the certain processing apparatus100A, and the second transport command is completed.

At this time, the transport vehicle controller50B allows the transport vehicle20A obtaining the FOUP90from the load port101of the certain processing apparatus100A to travel from the position to transfer a FOUP90to the load port101to another position on the track10.

In the transport system1, first withdrawal control, second withdrawal control, and third withdrawal control described below preferably are performed.

First of all, the first withdrawal control performed in the following situation will be described by way of example. As illustrated inFIG. 5, a FOUP90is placed on the load port101of the certain processing apparatus100A, of three certain processing apparatuses100A,100B, and100C disposed along the section10c. Therefore, at this time, the certain processing apparatus100A is not in a situation where a FOUP90is transportable to its load port101. The transport vehicle20A to which the first transport command has been allocated and has transported the FOUP90to the standby section30waits at the standby point32awhile holding the FOUP90to be transported to the load port101of the certain processing apparatus100A.

In such a situation, for example, when some trouble occurs in the certain processing apparatus100A, the controller50, or the like, the transport vehicle20A waiting at the standby point32amay be unable to transport the FOUP90to the load port101of the certain processing apparatus100A and stay at the standby point32a.

In this case, when determining that a first standby section-withdrawal condition (standby section-withdrawal condition) is satisfied, the transport controller50A creates a third transport command to transport a FOUP90to a predetermined destination. The transport controller50A then transmits a third transport command to the transport vehicle controller50B. The transport vehicle controller50B receiving the third transport command allocates the third transport command to the transport vehicle20A. Here, the first standby section-withdrawal condition is satisfied when a predetermined time or longer has elapsed since the transport vehicle20A reaches the standby section30. Although here the predetermined destination is the stocker40, any other destination may be set.

Subsequently, as illustrated inFIG. 6, the transport vehicle20A transports the FOUP90from the standby point32ato the stocker40, and the third transport command is completed. The first withdrawal control is thus completed.

Next, the second withdrawal control performed in the following situation will be described by way of example. As illustrated inFIG. 7, a FOUP90is placed on the load port101of each of three certain processing apparatuses100A,100B, and100C disposed along the section10c. Therefore, at this time, the certain processing apparatuses100A,100B, and100C are not in a situation where FOUPs90are transportable to their load ports101. The transport vehicles20A,20B,20C,20D,20E that have been allocated the first transport command and have transported FOUPs90to the standby section30wait at the standby points32a,32b,32c,32d, and31while holding FOUPs90to be transported to the load port101of any of certain processing apparatuses100A,100B, and100C.

In this situation, for example, when some trouble occurs in the certain processing apparatuses100A,100B, and100C, the controller50, or the like, the transport vehicles20A,20B,20C,20D, and20E waiting at the standby points32a,32b,32c,32d, and31may be unable to transport FOUPs90to the load ports101of the certain processing apparatuses100A,100B, and100C and stay at the standby points32a,32b,32c,32d, and31. In such a case, a place for another new transport vehicle20to wait is not secured unless at least one of the transport vehicles20A,20B,20C,20D, and20E waiting in the standby section30is withdrawn from the standby section30.

In this case, the transport controller50A creates a third transport command when determining that a second standby section-withdrawal condition (standby section-withdrawal condition) is satisfied. The transport controller50A then transmits the third transport command to the transport vehicle controller50B. The transport vehicle controller50B receiving the third transport command allocates the third transport command to at least one of the transport vehicles20A,20B,20C,20D, and20E. Here, the second standby section-withdrawal condition is satisfied when at least a predetermined number of transport vehicles20are waiting in the standby section30. Although in this example, the predetermined number is five, by way of example, any number may be set.

Subsequently, at least one of the transport vehicles20A,20B,20C,20D, and20E transports the FOUP90from the standby points32a,32b,32c,32d, and31to a predetermined destination, and the third transport command is completed. The second withdrawal control is thus completed. Although in this example, the predetermined destination is the stocker40, any other destination may be set.

The third withdrawal control performed in the following situation will now be described by way of example. As illustrated inFIG. 8, a FOUP90is placed on the load port101of each of three certain processing apparatuses100A,100B, and100C disposed along the section10c. Therefore, at this time, each of the certain processing apparatuses100A,100B, and100C is not in a situation where a FOUP90is transportable to its load port101. The transport vehicles20A and20B that have been allocated the first transport command and have transported FOUPs90to the standby section30wait at the standby points32aand32b, respectively, while holding FOUPs90to be transported to the load ports101of the certain processing apparatuses100A and100B. The transport vehicle20C that has been allocated the first transport command and has transported a FOUP90to the standby section30waits at the standby point32cwhile holding a FOUP90to be transported to the load port101of the certain processing apparatus100C. Furthermore, in order to obtain the FOUP90placed on the load port101of the certain processing apparatus100C, the transport vehicle20D is at a position to transfer the FOUP90to the load port101of the certain processing apparatus100C.

In such a situation, the transport vehicle20D obtains the FOUP90placed on the load port101of the certain processing apparatus100C. The certain processing apparatus100C thus enters a state in which a FOUP90is transportable to its load port101.

Subsequently, as illustrated inFIG. 9, the transport controller50A creates a transport command to withdraw from the standby section30. The transport controller50A then transmits the transport command to the transport vehicle controller50B. The transport vehicle controller50B receiving the transport command allocates the transport command to the transport vehicle20C waiting in the standby section30.

At this time, the transport controller50A creates a transport command to withdraw from the standby section30and transport a FOUP90to the standby section30again. The transport controller50A then transmits the transport command to the transport vehicle controller50B. The transport vehicle controller50B receiving the transport command allocates the transport command to the transport vehicles20A and20B downstream from the transport vehicle20C (ejection control).

In the ejection control described in this example, the second transport command to transport a FOUP90to the load port101of the certain processing apparatus100C is allocated, as the transport command to withdraw from the standby section30, to the transport vehicle20C. In the ejection control, the transport command to withdraw from the standby section30may not be the second transport command and may be, for example, a transport command under the first withdrawal control or the second withdrawal control.

In the example described here, the transport vehicle controller50B allocates a transport command to withdraw from the standby section30to the transport vehicle20C that is the most upstream transport vehicle20of a plurality of transport vehicles waiting in the standby section30. However, the transport vehicle20to be allocated the transport command to withdraw from the standby section30may be any other transport vehicle20, excluding the most downstream transport vehicle20, of the transport vehicles20waiting in the standby section30.

Subsequently, the transport vehicles20A and20B that have withdrawn from the standby section30and transported FOUPs90to the standby section30again wait in the standby section30while holding FOUPs90. The transport vehicle controller50B may allocate, to the transport vehicles20A and20B, again a transport command to withdraw from the standby section30and transport a FOUP90to the standby section30again.

In a situation where such ejection control is performed, for example, when some trouble occurs in the certain processing apparatuses100A,100B, the controller50, or the like, the transport vehicles20A and20B waiting at the standby points32aand32bmay be unable to transport FOUPs90to the load ports101of the certain processing apparatuses100A and100B and stay at the standby points32aand32b. Based on this, when ejection control is repeated for the same transport vehicles20A and20B a predetermined number of times or more, for example, some trouble may occur in the certain processing apparatuses100A,100B, the controller50, or the like.

Therefore, the transport controller50A creates a third transport command when determining that a third standby section-withdrawal condition (standby section-withdrawal condition) is satisfied. The transport controller50A then transmits the third transport command to the transport vehicle controller50B. The transport vehicle controller50B receiving the third transport command allocates the third transport command to the transport vehicles20A and20B waiting at the standby points32aand32b. Here, the third standby section-withdrawal condition is satisfied when the transport vehicle20that has been allocated the first transport command has withdrawn from the standby section30a predetermined number of times or more.

Subsequently, the transport vehicles20A and20B transport FOUPs90from the standby points32aand32bto the stocker40, and the third transport command is completed. The third withdrawal control is thus completed. Although here the predetermined destination is the stocker40, any other destination may be set.

As described above, in the transport system1and the transport method performed in the transport system1, even if a FOUP90is not transportable to the load ports101of the certain processing apparatuses100A,100B, and100C, the transport vehicle20picks up a FOUP90and starts traveling toward the standby section30. When the situation changes so that a FOUP90is transportable to the load ports101of certain processing apparatuses100A,100B, and100C, the transport vehicle20B travelling toward the standby section30or the transport vehicle20B having reached the standby section30and waiting while holding a FOUP90is able to immediately transport the FOUP90to the load ports101of the certain processing apparatuses100A,100B, and100C without the need for performing an operation, such as picking-up, again. This structure and operation decrease or prevent reduction in the operating rate of the certain processing apparatuses100A,100B, and100C.

In the transport system1, for example, even if FOUPs90are placed on the load ports101of the certain processing apparatuses100A,100B, and100C in the subsequent process and thus another FOUP90is unable to be transported to the load ports101of the certain processing apparatuses100A,100B, and100C, the transport vehicle20is able to transport another FOUP90, for example, from the load port of the processing apparatus100in the previous process to the standby section30. This structure and operation reduce the time required to pick up a FOUP90from the load port101of the processing apparatus100in the previous process. This decreases or prevents reduction in the operating rate of the processing apparatus100in the previous step.

In the transport system1, when determining that the standby section-withdrawal condition is satisfied, the transport vehicle controller50B allocates the third transport command to transport a FOUP90to the stocker40to the transport vehicle20that has been allocated the first transport command. This structure and operation prevent, for example, the transport vehicle from staying in the standby section30due to some trouble occurring in the certain processing apparatuses100A,100B, and100C.

In the transport system1, when the transport vehicle controller50B determines, as the first standby section-withdrawal condition, that a predetermined time or longer has elapsed since the transport vehicle20that has been allocated the first transport command reaches the standby section30, the transport vehicle controller50B allocates the third transport command to the transport vehicle20. This prevents, for example, the transport vehicle20from staying in the standby section30due to some trouble occurring in the certain processing apparatuses100A,100B, and100C.

In the transport system1, when the transport vehicle controller50B determines, as the second standby section-withdrawal condition, that a predetermined number or more transport vehicles20wait in the standby section30, the transport vehicle controller50B allocates the third transport command to at least one of the transport vehicles20. This prevents, for example, the transport vehicle20from staying in the standby section30due to some trouble occurring in the certain processing apparatuses100A,100B, and100C.

In the transport system1, the transport vehicle20travels along the track10in one direction. When a plurality of transport vehicles20are waiting in the standby section30, and a transport command to withdraw from the standby section30is allocated to one of the transport vehicles20, excluding the most downstream transport vehicle20, of the transport vehicles20, the transport vehicle controller50B allocates, to another transport vehicle20downstream from the transport vehicle20, a transport command to withdraw from the standby section30and transport a FOUP90to the standby section30. When the transport vehicle controller50B determines, as the third standby section-withdrawal condition, that the transport vehicle20that has been allocated the first transport command withdraws from the standby section30a predetermined number of times or more, the transport vehicle controller50B allocates the third transport command to the transport vehicle20. This prevents, for example, ejection control from being repeated due to some trouble occurring in the certain processing apparatuses100A,100B, and100C.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the foregoing preferred embodiments. For example, in the foregoing preferred embodiments, the transport vehicle20preferably travels along the track10in one direction. However, the transport vehicle20may travel along the track10bidirectionally.

In the foregoing preferred embodiments, the transport system1preferably includes three certain processing apparatuses100A,100B, and100C in the section10c. However, the transport system1may include more than three certain processing apparatuses or may include less than three (one or two) certain processing apparatuses in the section10c.

As illustrated inFIG. 10, the transport vehicle20may travel along the track10in one direction. The standby section30may be connected in parallel with a second travel section33B continuous to the upstream side of a first travel section33A including the position to transfer a FOUP90to the load port101of each of the certain processing apparatuses100A,100B, and100C. In particular, one first travel section33A may be provided for the certain processing apparatuses100A,100B, and100C.

In this case, compared with the foregoing preferred embodiments, a section10fis connected in parallel with the section10b. That is, the section10bcorresponds to the second travel section33B, and the section10fcorresponds to the standby section30. Specifically, the section10fincludes an upstream side branching from the upstream side of the second travel section33B (section10b) and includes a downstream side merging with the downstream side of the second travel section33B (section10b), that is, the upstream side of the first travel section33A (section10c).

In such a track10, the transport vehicle20entering through the upstream side of the section10atravels from the section10ato the section10band then travels to the section10c. Alternatively, the transport vehicle20entering through the upstream side of the section10atravels from the section10ato the section10fand then travels to the section10c. The transport vehicle20traveling to the section10ctravels to the section10dand then exits to the downstream side. Alternatively, the transport vehicle20traveling to the section10ctravels from the section10cto the section10eand travels again to the section10b. The configuration of the track10in the figure is illustrated only by way of example and is not limitative.

In such a transport system1, the transport vehicle20travels along the track10in one direction. The standby section is connected in parallel with the second travel section33B continuous to the upstream side of the first travel section33A including the position to transfer a FOUP90to the load port101of each of the certain processing apparatuses100A,100B, and100C. This enables the transport vehicle20to wait in the standby section30without interrupting travel of the transport vehicle20from the second travel section33B to the first travel section33A.

In such a transport system1, one first travel section33A is provided for the certain processing apparatuses100A,100B, and100C. In this configuration, since one standby section30is associated with the certain processing apparatuses100A,100B, and100C, the area of the space necessary to provide the standby section30is able to be reduced.

In such a transport system1, three certain processing apparatuses100A,100B, and100C are provided in the first travel section33A including the position to transfer a FOUP90to the load port101of each certain processing apparatus. However, the transport system1may include more than three certain processing apparatuses or may include less than three (one or two) certain processing apparatuses in the first travel section33A.

In the foregoing preferred embodiments, the transport vehicle controller50B may be configured or programmed to perform all or a portion of the functions of the transport controller50A, or the transport controller50A may be configured or programmed to perform all or a portion of the functions of the transport vehicle controller50B. Alternatively, one controller50may be configured or programmed to perform the functions of the transport controller50A and the transport vehicle controller50B.

In the foregoing preferred embodiments, the object transported by the transport system1of the present invention is not limited to a FOUP90accommodating a plurality of semiconductor wafers and may be any other container accommodating glass wafers, reticles, and others. The transport systems according to preferred embodiments of the present invention are applicable to not only a semiconductor fabrication plant but also any other facilities.

In the foregoing preferred embodiments, an OHT has been illustrated as the transport vehicle20. However, the transport vehicle20may not be an OHT and may be any device that can travel along the track10and transport an object to the load port101of the processing apparatus100.