JP2002175107A - Process controlling method, its device, and program storage medium therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the lot flow of a production line for directly conveying lots between facilities without passing through any buffer in processing a plurality of sequential processes in a production system for processing a plurality of processes in a plurality of facilities. SOLUTION: This process controlling device is provided with a termination time prediction part 105 predicting a termination time in the final process 102 for a lot in process in the final process 102 of sequential processing, a termination time storage part 106 storing the predicted termination time, a processing time prediction part 103 predicting a processing time from the initial process 101 to a process preceding the final process 102 from a lot in process in the initial process 101 of sequential processing, a processing time storage part 104 storing the predicted processing time, and a lot controlling part 107 finding a processing starting time from the predicted termination time and the predicted processing time for instructing the lot in process in the initial process 101 to start processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process control method and apparatus in a production system in which a plurality of processes are processed by a plurality of facilities. In particular, a lot which has been completed in a certain facility is processed in the next process as soon as possible. In cases such as when the yield of non-defective products improves, the lot processed in one facility can be transported directly to the facility in the next process without storing it in the buffer that secures the work-in-process inventory for the next process. The present invention relates to a process control method and apparatus for controlling a desired production line lot flow and a program recording medium therefor.

[0002]

2. Description of the Related Art At present, a semiconductor production line comprises tens to hundreds of manufacturing steps, each of which comprises a plurality of facilities, and each facility can perform a plurality of processes.
In order to operate each equipment efficiently and improve the productivity of the entire production line, it is very important to determine which timing and which equipment should be used to process the work-in-process lot of each process. ing.

Conventionally, in a production system comprising a plurality of processes, each process comprising a plurality of equipment groups, in order to reduce the production loss such as the standby state of each equipment and increase the operation rate of each equipment, usually, A buffer is provided to secure work-in-process inventory between processes.

[0004] Each facility such as a semiconductor manufacturing line may be temporarily stopped due to various causes such as failure or maintenance. When the equipment of a certain process is stopped, the work-in-process stock of the process increases, and the work-in-process stock of the subsequent process decreases. At this time, if there is sufficient capacity to store the in-process inventory of the stopped equipment and the in-process inventory of the next process is sufficient, the equipment in the preceding and following processes can be produced without reducing the operation rate. It becomes possible. Therefore, in order to perform production without lowering the operation rate of each facility, it is preferable to prepare a buffer that can secure a sufficient in-process inventory.

However, securing a large amount of in-process inventory requires a place and cost for securing a large number of buffers. In addition, since the lead time from the start of production to completion is longer, the time from order receipt to delivery is longer in case of build-to-order manufacturing, and there is always an economic loss due to having excess inventory. I do. Therefore, in the current production system, in order to limit the number of in-process stocks in each process, a physical restriction is imposed on the number of in-process stocks according to the capacity of the buffer, or a predetermined number of in-process lots allowed in each process or each facility. Limiting the number of stocks prevents unnecessary increase in work-in-process stock.

In a production method generally called a push-type production system, a production instruction is given to a first step, and the production instruction shifts from a previous step to a subsequent step. In each process, in order to process the processed lot in the equipment group of the next process, the availability of a port for storing a lot attached to the equipment of the next process is checked. If there is a vacancy, the lot is conveyed to the port for the next process, and waits for processing at that facility. If there is no vacancy in the port of the next process, it is transported to a buffer for storing the work-in-process inventory.

In a production method generally called a pull-type production system, a production instruction is given to a final step, and the production instruction shifts from a subsequent step to a previous step. In each process, when an order is received from a subsequent process, the process is started using the in-process inventory of the process, and at the same time, an order is placed in the preceding process by the reduced amount of the in-process inventory to replenish the in-process. Therefore, in this production method, the in-process stock of each process does not exceed a predetermined number.

In Japanese Patent Application Laid-Open No. 10-161708, a lot existing in a buffer is immediately started in order to perform start control so that the number of waiting lots in a facility group having a finite buffer does not exceed the maximum capacity of the finite buffer. In the case, the working time in each equipment group having a finite buffer continuous in the process procedure,
Based on the current and future status of the equipment and buffers in the equipment group in the continuous block managed by the work start control unit and the scheduling unit, predictions are made in the order of consecutive processes, and when a lot is started immediately, the continuous block After confirming that there is no work waiting in each equipment group, the work of the lot is started based on the estimated work time.

[0009]

In an actual semiconductor production system, the yield of non-defective products may be better if the lots that have been processed in a certain facility are processed in the next step as soon as possible. In such a case, it is desired that the lot processed by a certain facility be directly transported to the facility of the next process for processing without being stored in a buffer for securing the stock of the in-process lot of the next process.

In the conventional push-type production system, when the above-mentioned production without passing through a buffer is performed in some processes, a lot which has been processed in a certain process is processed by a next process equipment group in order to process the lot in a next process facility group. The availability of a port for storing the incidental lot in the facility is confirmed, and if there is a vacancy, it is transported to the port of the next process. Then, this lot waits to be processed by the equipment. However, if there is no vacancy in the port of the next process, it is necessary to wait for the port of the next process to be vacant. This is because it cannot go through the buffer. In that facility, the next lot cannot be carried in due to the lot that cannot be discharged, and the operating rate decreases. Also, if a facility that cannot discharge a lot is responsible for multiple processes, it cannot process a lot in a process different from the lot that cannot be discharged. Will be reduced. Therefore, in the conventional push-type production system, there is a problem that unless a buffer for temporarily evacuating a work-in-progress lot is secured, the operation rate of equipment in processes before and after the process assigned to the equipment is adversely affected.

On the other hand, in the conventional pull-type production system, when the production without passing through the buffer as described above is performed in a part of continuous processes, if an order is placed in the last process of these continuous processes, the process is not performed. Since there is no work-in-progress stock, this process is ordered for the previous process. In the previous process, if there is no work-in-progress stock in that process, an order is made to the previous process. After all, if there is an order for the last step in the series,
The first process in the continuous process processes the work-in-process stock, and the processes are sequentially performed from that process to the last process in the continuous process. Therefore, when it is desired to perform the processes continuously, a time lag corresponding to the working time of the continuous process from ordering to the last process of the continuous process for performing these processes until completion of the process in the last process is performed. There is a problem that occurs.

The method of controlling the lot flow of a production line proposed in Japanese Patent Application Laid-Open No. H10-161708 controls the start of work in each equipment group so as to satisfy the buffer capacity constraint. Is provided with a limited number of buffers, and it is not assumed that there is no buffer capacity. Therefore, when a lot that has been processed in a certain process is to be transported directly to equipment in the next process for processing without being stored in a buffer that secures the work-in-process inventory for the next process, the lot If the start is controlled, lots that have completed processing in the first step for continuous processing will wait for the next step to open a port, or conversely, there will be no lot to process in the next step. Therefore, the equipment cannot be operated efficiently.

Therefore, in a production system in which a plurality of processes are processed by a plurality of facilities, a lot flow of a production line in which it is desired to process a plurality of continuous processes directly between the facilities without passing through a buffer. It is a first object of the present invention to provide a process control method and an apparatus for controlling the process. It is a second object of the present invention to provide a computer-readable recording medium on which a program for realizing such an apparatus is recorded.

[0014]

To achieve the above object, a process control method for controlling a lot flow of a production line in a production system according to a first aspect of the present invention in which a plurality of processes are performed by a plurality of facilities. Is a process control method for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities, and is a continuous process forming at least a part of all processes performed in the production system. For the in-process lot in the last step, predicting the end time in the last step; and for the in-process lot in the first step of the continuous process, from the first step to the last step. Estimating the processing time up to the process immediately before the process, the predicted end time and the predicted processing time, the in-process lot in the first process. Determining a processing start time for, after the processing start time has elapsed, and a step of instructing to start processing of the in-process lot in the first step to the corresponding equipment.

The processing start time in the continuous process for the continuous processing of the in-process lot is calculated from the predicted end time of the in-process lot in the last process for the current continuous process, and the in-process lot in the first process. For the process from the first process to the process immediately before the last process. Then, if the obtained processing start time has not yet elapsed, after the elapse of the time, for example, immediately, on the other hand, if the obtained processing start time has already passed, for example, immediately, the in-process lot Is instructed to the equipment which performs the first step of the continuous processing, so that the processing of the in-process lot is continuously performed from the first step to the last step for the continuous processing. If the processing start of the in-process lot is instructed immediately after the obtained processing start time, the in-process lot arrives at the last process in the calculation because of the prediction of the lot used to obtain the processing start time. Immediately after the end time. Therefore, in the last step, it is possible to process incoming work lots one after another without letting the equipment idle.

The process control method is, for example, a process control apparatus for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities,
An end time prediction unit for estimating an end time in the last step of the in-process lot in the last step of a continuous step constituting at least a part of all the steps performed in the production system; An end time storage unit that stores the end time predicted by the time prediction unit, and a work-in-process lot in the first step of the continuous steps, from the first step to the step immediately before the last step. A processing time prediction unit for predicting a processing time, a processing time storage unit for storing the processing time predicted by the processing time prediction unit, and a processing lot stored in the first process, stored in the end time storage unit. A processing start time is obtained from the completed end time and the processing time stored in the processing time storage unit, and after the processing start time has elapsed, the processing start of the in-process lot in the first process is set. It can be realized by using a lot control unit for instructing the process control device provided to.

According to a second aspect of the present invention, a process control method for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities is provided. A process control method for controlling a lot flow of a production line in
For a work-in-process lot in the first step of a continuous process constituting at least a part of all the processes performed in the production system, a process immediately before the last process of the continuous process from the first process. Estimating the processing time up to, obtaining the processing start time for the in-process lot in the first process, and processing the in-process lot in the first process after the processing start time has elapsed. A step of instructing the corresponding equipment to start, and after instructing the processing start, for a work in process lot in the first step, comprising a step of predicting an end time in the last step of the continuous step, In the step of obtaining the processing start time for the in-process lot in the first process, the process of the last process predicted for the in-process lot being processed in the continuous process is performed. And completion time, and a predicted processing time with respect to the work-in-progress batch is in said first step, and obtains the processing start time for the in-process lots in this first step.

The process control method according to the second aspect of the present invention is different from the process control method according to the first aspect in that the process control method for the continuous processing of the in-process lot in the first step of the continuous steps. This is how to find the start time. In other words, in the first method, the processing start time is set to the end time predicted for the in-process lot in the last step for the current continuous processing and the first time predicted for the in-process lot in the first step. On the other hand, the method is based on the processing time from the step to the step immediately before the last step.
The end time in the last step predicted when the in-process lot being processed in the continuous process is in the first step, and the first time predicted for the in-process lot waiting for processing in the current first step The processing start time is obtained from the processing time from the step to the step immediately before the last step. By using this method, the end time of the last process of this in-process lot is obtained while the in-process lot is in the first process, so the accuracy of the end time prediction is It may be worse than you ask for at some point. If this is not done, the transfer of the in-process lot is interposed between the equipments, and the transfer time varies depending on factors such as congestion of the transfer route and the transfer path. Further, as the process proceeds, the number of works included in the lot may decrease due to the occurrence of defective products. For this reason, the prediction end time is more likely to differ from the actual end time as the prediction is made earlier. However, on the other hand, this process control method has an advantage that the operation rate of equipment for the last process can be increased. This is because when the end time of the last process is predicted when the in-process lot is actually in the last process, the processing of the in-process lot starts when the previous in-process lot is actually in the last process. Since it is not performed until after arrival, depending on the length of processing time from the first step to the step immediately before the last step, there may be time to play the equipment that performs the last step. This is because, in the case of this method, even if the previous in-process lot has not actually arrived at the last step, the processing start can be instructed to the equipment.

This process control method is, for example, a process control device for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities,
For a work-in-process lot in the first step of a continuous process constituting at least a part of all the processes performed in the production system, a process immediately before the last process of the continuous process from the first process. A processing time prediction unit that predicts the processing time up to, a processing time storage unit that stores the processing time predicted by the processing time prediction unit, and a work-in-process lot in the first process, An end time prediction unit for predicting an end time, an end time storage unit for storing the end time predicted by the end time prediction unit, and a work in process in the continuous process stored in the end time storage unit From the end time of the lot and the processing time for the in-process lot in the first process stored in the processing time storage unit, the processing start time of the in-process lot in the first process is obtained, and After the lapse of the start time, it can be achieved by using a process control device and a lot control unit for instructing to start processing of the in-process lot in the first step to the corresponding equipment.

Further, a process control method for controlling a lot flow of a production line in a production system according to a third aspect of the present invention, in which a plurality of processes are performed by a plurality of facilities, performs a plurality of processes by a plurality of facilities. A process control method for controlling a lot flow of a production line in a production system, comprising: one of a first step to a last step of a continuous step constituting at least a part of all steps performed in the production system. Preparing in advance a predicted processing time up to the previous step; predicting an end time in the last step for the in-process lot in the last step; Obtaining a processing start time for the in-process lot in the first process from the prepared estimated processing time; and And a step of instructing to start processing of the in-process lot in the process into the corresponding facilities.

While the above two methods predict the processing time from the first step to the step immediately before the last step and the end time of the last step in order to obtain the processing start time, In this method, the processing time from the first step to the step immediately before the last step is prepared in advance. That is, the processing time from the first step to the step immediately before the last step is not individually obtained for each in-process lot. Therefore, although the accuracy of the lot flow control is likely to be inferior to the above two methods, there is an advantage that the lot flow control can be easily performed because the processing time is not individually predicted.

This process control method is, for example, a process control device for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities,
An end time prediction unit for estimating an end time in the last step of the in-process lot in the last step of a continuous step constituting at least a part of all the steps performed in the production system; An end time storage unit that stores the end time predicted by the time prediction unit, and a processing time that stores a previously prepared prediction processing time from the first step of the continuous steps to the step immediately before the last step A processing start time for the in-process lot in the first process is obtained from a storage unit, an end time stored in the end time storage unit, and an estimated processing time stored in the processing time storage unit. After the elapse of the processing start time, it can be realized by using a process control device including a lot control unit that instructs a corresponding facility to start processing the in-process lot in the first process.

In the process control method according to the third aspect of the present invention, in the step of preparing the predicted processing time in advance, a step of preparing a plurality of predicted processing times according to different conditions and obtaining the processing start time Then, one of the plurality of predicted processing times may be used according to the in-process lot. In this way, compared to the case where only one predicted processing time is used for all lots, it is possible to use a predicted processing time that is more appropriate for the in-process lot to be processed, and the accuracy of the lot flow control can be improved. Increase.

When this method is applied to the process control device, the processing time storage unit stores a plurality of predicted processing times prepared according to different conditions, and the lot control unit When obtaining the processing start time for the in-process lot in the process (1), the estimated processing time corresponding to this in-process lot is used.

In each of the above methods, in the step of predicting the end time, when the equipment assigned to the last step has a plurality of ports, the end time is predicted for each port, and the processing time is reduced. In the prediction step,
If multiple in-process lots arrive at the first step,
In the step of estimating the processing time of each of the in-process lots and obtaining the processing start time, obtaining the processing start time of each of the plurality of in-process lots, and in the step of instructing the processing start, in accordance with a predetermined standard One of the plurality of in-process lots may be selected, and an instruction to start processing the selected in-process lot may be given.

In this case, in any of the various process control devices described above, the lot control unit obtains the processing start time of each of the plurality of in-process lots, and determines the processing start time of the plurality of in-process lots according to a predetermined standard. One is selected, and the processing start of the selected in-process lot is instructed. The lot control unit can select a lot based on, for example, the order of arrival in the first process. The selection of the lot may be performed in the order of the processing start time, or based on a margin for the delivery date of the lot.

According to the present invention, even when any of the above-described configurations is adopted, when it is desired to continuously process an in-process lot in a plurality of steps, the in-process lot can be installed between the equipments performing the plurality of continuous steps. Can be instructed to start processing a work-in-process lot so that is directly conveyed and processed without passing through a buffer.

In one embodiment, the end time predicting section predicts the end time based on a prediction material including at least information on the in-process lot itself and information on the corresponding equipment. The processing time is predicted based on a prediction material including at least information on the in-process lot itself, information on the corresponding equipment, and information on transportation.

The information concerning the in-process lot itself may be such that each in-process lot itself carries such information in the form of an ID card mounted on a cassette accommodating the in-process lot. In this case, the process control device further includes means for reading the information.

[0030] The process control device may further comprise a sensor means for detecting that the in-process lot has arrived at the first process, and in this case, the reading means comprises:
Receiving a signal from the sensor means, the information on the in-process lot can be read, and the processing time prediction section can use the information read by the reading means as one of the prediction materials.

In one embodiment, the lot control unit instructs the start of processing of the in-process lot in the first process, and then sets the end time in the last process used to determine the start of processing of the lot. The data is discarded from the end time storage unit. As a result, the end time of the last step used to determine the processing start time of a certain lot is
It can be prevented from being used for obtaining the processing start time of another lot by mistake.

Further, according to the present invention, in order to control a lot flow of a production line by computer in a production system in which a plurality of processes are performed by a plurality of facilities, a continuous system constituting at least a part of all the processes performed in the production system. Estimating the end time in the last step for the in-process lot in the last step of performing the step, storing the predicted end time in the end time storage unit, Estimating the processing time from the first step to the step immediately before the last step for the in-process lot in the step; storing the predicted processing time in a processing time storage unit; From the end time stored in the end time storage unit and the processing time stored in the processing time storage unit, processing for the in-process lot in the first process is started. A computer-readable program storing a program for causing a computer to execute a step of obtaining a time and a step of instructing a corresponding facility to start processing of the work-in-process lot in the first step after a processing start time has elapsed. A recording medium is provided.

Such a program recording medium may be in any form such as an optical disk, a magnetic disk, and a magneto-optical disk.

According to the present invention, in order to control a lot flow of a production line by computer in a production system in which a plurality of processes are performed by a plurality of facilities, a continuous system constituting at least a part of all processes performed in the production system is used. Estimating the processing time from the first process to the process immediately before the last process of the continuous process for the in-process lot in the first process of performing the process, From the data stored in the end time storage unit and the processing time stored in the processing time storage unit, the processing start time for the in-process lot in the first process is stored. Seeking steps;
After the processing start time has elapsed, a step of instructing the corresponding equipment to start processing the in-process lot in the first step, and after the processing start instruction, for the in-process lot in the first step, Provided is a computer-readable program recording medium storing a program for causing a computer to execute a step of predicting an end time in the last step of the continuous steps and a step of storing the predicted end time in an end time storage unit. .

Still further, the present invention constitutes at least a part of all the steps performed in the production system in order to computer-control the lot flow of the production line in the production system in which the plurality of steps are performed by the plurality of facilities. For the in-process lot in the last step of the continuous process, a step of predicting an end time in the last step, a step of storing the predicted end time in the end time storage unit, Obtaining a processing start time for the in-process lot in the first process from the stored predicted end time and the predicted processing time stored in advance in the processing time storage unit; and after the processing start time has elapsed. Recording a program for causing a computer to execute a step of instructing a corresponding facility to start processing the in-process lot in the first step. And a computer-readable program recording medium.

Preferably, the processing time storage section stores a plurality of predicted processing times according to different conditions.
This is because, in the step of obtaining the processing start time, one of the plurality of predicted processing times can be selected from the plurality of predicted processing times in accordance with the in-process lot.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a block diagram showing a configuration of a process control device according to a first embodiment of the present invention. In FIG. 1, reference numeral B generally indicates a production system in which a plurality of processes (for example, processes for producing semiconductor devices) are processed by a plurality of facilities, and reference numeral B indicates a computer constituting a process control device. ing. A process control program for controlling the lot flow in the production system A according to the procedure shown in FIG.

In the semiconductor manufacturing process, if a part of the continuous process is processed as soon as possible, the yield is improved in terms of quality and the like. It is desired to directly transport and continuously process. Therefore, in this embodiment, it is assumed that, of all the processes in the production system A, such a part of the continuous processes is directly transported between the equipments without passing through a buffer to perform processing. 101 is the first step 101 of the continuous steps for performing such continuous processing, and 102 is the last step. Here, there are two steps from the first step for continuous processing (hereinafter simply referred to as “first step”) 101 to the last step for continuous processing (hereinafter simply referred to as “last step”) 102. Or three or more steps. In addition, a plurality of facilities assigned to each process for continuous processing may perform another process.

The process control device includes a processing time prediction unit 103,
It includes a processing time storage unit 104, an end time prediction unit 109, an end time storage unit 106, a lot control unit 107, and predicted material storage units 108 and 109. Processing time prediction unit 103,
The end time prediction unit 109 and the lot control unit 107
It is configured by a CPU mounted on a computer.
Further, the processing time storage unit 104, the end time storage unit 106,
Although the prediction material storage units 108 and 109 are configured by hard disks built in a computer, they may be configured by an external storage device such as a floppy (registered trademark) disk or an optical disk. Each component of the process control device operates as follows.

The processing time estimating unit 103 executes the first step 10
The processing time from the first process 101 to the process immediately before the last process 102 is predicted for the in-process lot (hereinafter, simply referred to as “lot”) that has arrived at No. 1. The processing time includes the number of workpieces included in the lot, the model of the lot (type of semiconductor device, etc.), setup change time, each facility capacity, transport route,
Since the processing time differs depending on the congestion degree of the transportation and the like, the processing time is estimated in consideration of these. Here, information about the lot, such as the number of works included in the lot and the model of the lot, is usually recorded on an ID plate attached to a cassette accommodating the work, and the ID plate is read by an appropriate reading device (see FIG. (Not shown). On the other hand, the setup time,
Information on the equipment side such as the transport route and the congestion degree of the transport is stored in the predicted material storage unit 108. Therefore, the processing time prediction unit 103 makes a prediction based on the information sent from the reading device and the information read from the prediction material storage unit 108. Note that the information read by the reading device may be temporarily stored in the predicted material storage unit 108 and read out. Further, a material for prediction can be input via a keyboard.

The processing time storage unit 104 stores the processing time predicted by the processing time prediction unit 103.

The end time prediction unit 105 determines whether the last step 10
The end time of the processing in the last step 102 is predicted for the lot in lot No. 2. If there are a plurality of facilities assigned to the last step 102 and each facility has a plurality of ports for storing lots, the end time is predicted for each of the ports.

Since the processing time of the last step 102 varies depending on the number of works included in the lot, the model of the lot, the setup change time, each facility capacity, and the like, the end time is predicted from the processing time taking these factors into consideration. Here, as described above, information about the lot, such as the number of works included in the lot and the model of the lot, is usually recorded on an ID plate attached to a cassette containing the work. It can be obtained by reading with a simple reading device (not shown). On the other hand, equipment-side information such as the setup change time and each equipment capacity is stored in the predicted material storage unit 109 (in the last step, information on transportation such as the transportation route and the congestion degree of transportation is unnecessary). Therefore, the end time prediction unit 10
Reference numeral 5 performs prediction based on information sent from the reading device and information read from the prediction material storage unit 109.
Note that information read by the reading device may be temporarily stored in the predicted material storage unit 109 and read out. Further, a material for prediction can be input via a keyboard.

The end time storage unit 106 stores the end time predicted by the end time prediction unit 105. If there are a plurality of facilities assigned to the last step 102 and each facility has a plurality of ports for storing lots, the end time is stored for each of the ports.

The lot control unit 107 executes the first process 101
For each lot arriving at the processing time, the processing start time of the lot arriving at the first process 101 is obtained from the processing time stored in the processing time storage unit 104 and the end time stored in the end time storage unit 106. . Then, if there is a lot whose processing start time has passed, one of the lots is selected, and an instruction to start processing for the selected lot is given to the facility in charge of the first process 101. Lot control unit 107
In, a method for selecting a lot to start processing from a plurality of lots arrived in the first step 101,
There are an order of arrival at the first step 101 earlier, an order of earliest processing start time for each lot, a margin for lot delivery date, and the like.

FIG. 4 is a flowchart for explaining the processing procedure of the process control device shown in FIG. Hereinafter, FIG.
The operation will be described with reference to FIG.

This flowchart describes the process from when a lot arrives at the first process 101 (step 401) to when the process of the last process 102 is completed and transported to the equipment of the next process (step 413). .

In general, it is considered that the first step 101 starts when the step immediately before the first step 101 is completed. (Step 401) "
The lot may be in the equipment port of the process immediately before the first process 101, or may be in a buffer for storing the work-in-process stock of the first process 101.

When the lot arrives at the first step 101,
The processing time prediction unit 103 predicts the processing time from the first step to the step immediately before the last step (step 402). In predicting the processing time, as shown in the prediction subroutine of FIG. 5, information on the ID plate is read by a reader (not shown) (step 30).
0) On the other hand, information is read from the prediction material storage unit (step 301), and prediction is performed using these information (step 302). Here, the arrival of the lot to the first step 101 can be known by using the sensor means. For example, an optical sensor is attached to a predetermined location in the equipment (for example, a port of the equipment that performs the process immediately before the first process 101, a buffer that stores the work-in-process inventory of the first process 101, etc.), and What is necessary is just to input the lot detection signal from the optical sensor to the computer B.

Then, the processing time storage section 104 stores the processing time predicted by the processing time prediction section 103 for each lot (step 403).

Next, the lot waits for a processing start instruction from the lot control unit 107 (step 404). In the lot control unit 107, the end time stored in the end time storage unit 106 for each port of each facility assigned to the last process 102 and the processing time storage unit 104 arrives at the first process 101. From the processing time stored for each lot, an instruction is given to the lot that has arrived at the first process 101 and is on standby to start processing in the equipment assigned to the first process 101. For example, when the processing time of the lot arriving at the first process 101 is 20 minutes, and the end time of the port having the equipment allocated to the last process is 30 minutes later, and the lot is processed at the port, After 10 minutes, a processing start instruction is given. Here, there may be a plurality of lots arriving at the first step 101, and there may be a plurality of ports of each equipment assigned to the last step 102, and which lot is processed by which equipment. There are multiple combinations. The lot control unit 107 determines which lot to start processing.

When an instruction to start processing in the first process 101 is given to a certain lot, the lot control unit 107
Instructs the end time storage unit 106 to discard the end time used to determine the processing start of the lot (step 405). In this way, until the lot arrives at the last step 102 and the end time is predicted and stored, the processing is not started using the end time for another lot.

After performing the processing in the first step 101 (step 406), the lot is transferred to the equipment of the next step (step 407). Therefore, it is determined whether or not the process is the last process 102 (step 408). If the process is not the last process 102, the process in that process is executed (step 409), and the process returns to step 407. In step 408, if it is the last step 102, the end time prediction section 105 predicts the end time of the last step 102 (step 410), and for each port of the equipment allocated to the last step 102 The end time predicted by the end time prediction unit 105 is stored in the end time storage unit 1.
06 is stored (step 411). Note that the same subroutine as that shown in FIG. 5 is executed for the end time prediction.

Finally, the last step 10 for continuous processing
After executing the process in step 2 (step 412), the next step is carried to the equipment (step 413).

FIG. 8 is an example of a time chart for explaining the processing result of the process control device shown in FIG.

In this time chart, equipment 1 is assigned to both steps (i) and (j), equipment 2 is assigned to step (i + 1), and equipment 3 is assigned to step (j + 1). Have been. Also, from R1 to R
8 is a lot number for distinguishing lots. R1, R3,
For the lots of R5 and R7, after the processing in the step (i) is performed in the equipment 1, the processing in the step (i + 1) is performed in the equipment 2. Since the process (i) and the process (i + 1) are to be processed in succession, after the process is completed in the facility 1, the process (i) is directly transferred to the facility 2 without passing through the buffer for storing the work-in-process inventory. The lots of R2, R4, R6, and R8 are processed in the equipment 1 after the processing in the step (j) is performed.
In step (j + 1), the process is performed. Since the process (j) and the process (j + 1) are also desired to be performed continuously, after the process is completed in the facility 1, the product is directly conveyed to the facility 3 without passing through the buffer for storing the work-in-process inventory.

Next, a description will be given with reference to this time chart. First, when the processing in the step (i) is completed in the equipment 1 for the lot R1, the lot R1 is directly conveyed to the equipment 2 without passing through the buffer for storing the work-in-process inventory. Then, the process of step (i + 1) is started, and the end time of the lot R1 in the facility 2 is predicted. For the lot R2, when the processing in the step (j) is completed in the equipment 1, the lot R2 does not pass through the buffer for storing the work-in-process inventory,
It is transported directly to the equipment 3. Then, the process of the step (j + 1) is started, and the end time of the lot R2 in the facility 3 is predicted. For lots R3, R4,..., When these become the work-in-process inventory of the process (i) and the process (j), the processing time in the facility 1 is predicted. Lot control unit 10
7 is to select a lot to be put into the facility 1 based on the end time of the lot being processed by the facilities 2 and 3 and the processing time of the lot in process of the work in process (i) and the step (j) in the facility 1. Decide when to put in. Here, next, according to the instruction of the lot control unit 107, the processing of the step (i) is started in the equipment 1 for the lot R3.
Further, according to the instruction of the lot control unit 107, the processing in the step (j) is started in the equipment 1 for the lot 4.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
It is a block diagram showing the composition of the process control device concerning an embodiment. In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals as those used in FIG. 1, and detailed description is omitted.

In the first embodiment, the end time predicting section 105 predicts the end time for the lot in the last step 102. In the second embodiment, however, the end time predicting section 105 determines the end time. The time prediction unit 105 ′ predicts the end time of the processing in the last step 102 for the lot that has arrived in the first step 101. Then, the predicted end time is used to calculate the processing start time of the next lot to be processed. The second embodiment differs from the first embodiment only in this point.

FIG. 6 is a flowchart for explaining the processing procedure of the process control device shown in FIG. The operation will be described below with reference to FIGS.

The flowchart starts from when the lot arrives at the first step 101 for performing the continuous processing (step 501), and ends when the processing of the last step 102 is completed and transported to the next step (step 513). Has been described.

When the lot arrives at the first step 101 (step 501), the lot may be at the port of the equipment of the step immediately before the first step 101, or stores the in-process stock of the first step 101. May be in the buffer.

When the lot arrives at the first step 101,
The processing time prediction unit 103 predicts the processing time from the first step to the step immediately before the last step according to the subroutine shown in FIG. 5 (step 502). The processing time storage unit 104 stores the processing time predicted by the processing time prediction unit 103 for each lot (step 503).

Next, the lot waits for a processing start instruction from the lot control unit 107 (step 504). In the lot control unit 107, the end time stored in the end time storage unit 106 for each port of each facility assigned to the last process 102 and the processing time storage unit 104 arrives at the first process 101. From the processing time stored for each lot, the processing start time for the lot that has arrived at the first process 101 and is on standby is determined.
An instruction to start processing in the equipment assigned to 01 is issued.

Once the start of the process in the first step 101 is instructed for a certain lot, the end time stored in the end time storage unit 106 used to determine the start of the lot is discarded (step 505). ). This is to prevent the processing from starting using the end time for another lot until the lot arrives at the last step 102 and the end time is predicted and stored.

Next, the end time predicting section 105 determines the last step 1
02 is predicted (step 506), and the end time predicted by the end time prediction unit 105 is stored in the end time storage unit 106 for each port of the equipment allocated to the last step 102.

After performing the processing in the first step 101 (step 508), the lot is transferred to the equipment of the next step (step 509). Therefore, it is determined whether or not the process is the last process 102 (step 510). If the process is not the last process 102, the process in that process is executed (step 511), and the process returns to step 509. If it is the last step 102 in step 510, the processing in the last step 102 is performed (step 51).
2) Convey the lot to the next process facility (step 5)
13).

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention.
It is a block diagram showing the composition of the process control device concerning an embodiment. In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals as those used in FIG. 1, and detailed description is omitted.

The device according to the third embodiment does not include the processing time prediction unit 103 and the prediction material storage unit 108 that the device according to the first embodiment has. That is, in the third embodiment, the processing time for each lot arriving at the first process 101 is not predicted, and the processing time storage unit 104 is not predicted.
Stored in advance are several types of predicted processing times.
Only this point is different from the first embodiment.

FIG. 7 is a flowchart for explaining the processing procedure of the process control device shown in FIG. The operation will be described below with reference to FIGS.

In this flowchart, when a lot arrives at the first step 101 for continuous processing (step 60)
From 1) to the completion of the processing of the last step 102 for continuous processing and transfer to the next step (step 611) are described.

As described in the previous embodiment, when a lot arrives at the first process 101 (step 601), the lot may be located at a port of the equipment of the process immediately before the first process 101. Alternatively, it may be in a buffer for storing the work-in-process stock of the first process 101.

In the processing time storage unit 104,
The processing time from the first step to the step immediately before the last step is stored.

When the lot arrives at the first step 101, the lot waits for a processing start instruction from the lot control unit 107 (step 602). In the lot control unit 107,
In the end time storage unit 106, the first step 101 is reached based on the end time stored for each port of each facility assigned to the last step 102 and the processing time stored in the processing time storage unit 104. Then, for the waiting lot, an instruction is given to start processing in the equipment assigned to the first process 101.

When the start of the process in the first step 101 is instructed for a certain lot, the end time stored in the end time storage unit 106 used to determine the start of the process of the lot is discarded ( Step 603). The reason is as described above.

Subsequently, after performing the process in the first step 101 (step 604), the lot is transferred to the equipment of the next step (step 605). Therefore, the last step 10
It is determined whether the number is 2 (step 606),
If it is not the last step 102, the processing in that step is executed (step 607), and the process returns to step 605. If it is the last step 102 in step 606, the end time prediction section 105 predicts the end time of the last step 102 (step 608), and the end time storage section 106 assigns the end time to the last step 102. The ending time predicted by the ending time prediction unit is stored for each port of the installed equipment (step 609).

Finally, after performing the process of the last step 102 (step 610), the lot is transferred to the equipment of the next step (step 611).

In the third embodiment, the more the estimated processing time stored in the processing time storage unit 104 in advance, the more accurately the lot flow can be controlled. But,
If the number is too large, it takes time to select an item suitable for the lot. Therefore, it is better to store an appropriate number. If quick processing is desired, only one processing time may be stored.

In the above embodiment, the case where the present invention is applied to a semiconductor device production line has been described, but it goes without saying that the present invention can be applied to any product production line.

[0080]

As is clear from the above description, the present invention has the following effects.

The first effect of the present invention is that the lot which has completed the processing in each facility is immediately controlled by controlling the timing of starting the processing of the lot arriving at the first step for performing the continuous processing. It can be transported to the process port. Therefore, in each equipment of a plurality of processes for continuously processing lots, the inability to discharge the lot impedes the flow of lots in the processes before and after the equipment, thereby reducing the operation rate of each equipment. Can be avoided.

A second effect of the present invention is that a product can be efficiently produced without generating a time lag corresponding to the processing time of a continuous process.

The third effect of the present invention is that the lot is controlled in accordance with the end time of the last step of a plurality of steps for continuously processing, so that the equipment of this last step is effectively used. That the operating rate can be increased. This is particularly effective when the last step is a rate-determining step in a continuous step.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a process control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a process control device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a process control device according to the first embodiment of the present invention.

FIG. 4 is a flowchart for explaining a processing procedure of the process control device shown in FIG. 1;

FIG. 5 is a flowchart showing a subroutine for predicting a processing time and an end time.

FIG. 6 is a flowchart for explaining a processing procedure of the process control device shown in FIG. 2;

FIG. 7 is a flowchart for explaining a processing procedure of the process control device shown in FIG. 3;

FIG. 8 is a time chart for explaining a processing result of the process control device shown in FIG. 1;

[Explanation of symbols]

 101 first process 102 last process 103 processing time prediction unit 104 processing time storage unit 105 end time prediction unit 105 'end time prediction unit 106 end time storage unit 107 lot control unit 108 prediction material storage unit 109 prediction material storage unit A computer B Production system

Claims (22)

[Claims] 1. A process control method for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities, comprising at least a part of all processes performed in the production system. For the in-process lot in the last process of the continuous process, a step of predicting the end time in this last process, and for the in-process lot in the first process of the continuous process, from this first process From the step of predicting the processing time up to the step immediately before the last step, the predicted end time and the predicted processing time, the processing start time for the in-process lot in the first step Obtaining a processing start time, and instructing a corresponding facility to start processing the in-process lot in the first step after a processing start time has elapsed. Process control method. 2. A process control method for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities, wherein at least a part of all processes performed in the production system is configured. Estimating the processing time from the first process to the process immediately before the last process of the continuous process for the in-process lot in the first process of the continuous process; and Determining a processing start time for the in-process lot; instructing a corresponding facility to start processing the in-process lot in the first process after the elapse of the processing start time; and instructing the processing start. And estimating the end time in the last step of the continuous process with respect to the in-process lot in the first process. In the step of determining the processing start time for the in-process, the end time of the last process predicted for the in-process lot being processed in the continuous process, and the in-process lot in the first process A process start time for the in-process lot in the first process from the predicted process time. 3. A process control method for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities, wherein at least a part of all processes performed in the production system is configured. Preliminarily preparing a predicted processing time from the first process of the continuous process to the process immediately before the last process, and, for the in-process lot in the last process, the end time in this last process. Estimating; and estimating a processing start time for the in-process lot in the first process from the estimated end time and the pre-established estimated processing time; after the elapse of the processing start time, Instructing a corresponding facility to start processing the in-process lot in the first step. 4. The process control method according to claim 3, wherein in the step of preparing the predicted processing time in advance, a plurality of predicted processing times are prepared in accordance with different conditions, and in the step of obtaining the processing start time, A process control method, wherein one of the plurality of predicted processing times is used according to a work-in-process lot. 5. The process control method according to claim 1, wherein, in the step of predicting the end time, a facility assigned to the last process has a plurality of ports. In the step of predicting an end time for each port, and predicting the processing time, when a plurality of in-process lots arrive at the first process, predicting a processing time of each of the in-process lots, In the step of obtaining a start time, a process start time of each of the plurality of in-process lots is obtained. In the step of instructing the start of the process, one of the plurality of in-process lots is selected according to a predetermined criterion, A process control method characterized by instructing a start of processing of a selected in-process lot. 6. A process control device for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities, and constitutes at least a part of all processes performed in the production system. For an in-process lot in the last step of a continuous process, an end time prediction unit that predicts an end time in the last step, and an end time storage unit that stores the end time predicted by the end time prediction unit. A processing time estimating unit for estimating a processing time from the first step to a step immediately before the last step for a work-in-process lot in a first step of the continuous steps; and A processing time storage unit that stores the processing time predicted in, for the in-process lot in the first process, the end time stored in the end time storage unit and the processing time storage unit A lot control unit for obtaining a processing start time from the stored processing time, and instructing the corresponding equipment to start processing the in-process lot in the first process after the elapse of the processing start time. Characteristic process control device. 7. A process control device for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities, and constitutes at least a part of all processes performed in the production system. A processing time prediction unit for predicting a processing time from the first step to a step immediately before the last step of the continuous step for a work-in-process lot in the first step of the continuous step; A processing time storage unit that stores the processing time predicted by the prediction unit; an end time prediction unit that predicts an end time in the last process for the in-process lot in the first process; In the end time storage unit that stores the end time predicted in, the end time of the in-process lot being processed in the continuous process stored in the end time storage unit, and in the processing time storage unit From the stored processing time for the in-process lot in the first step, the processing start time of the in-process lot in the first step is obtained, and after the elapse of the processing start time, the processing in the first step is performed. A lot control unit for instructing a corresponding facility to start processing of a work-in-process lot, the process control device comprising: 8. The process control device according to claim 6, wherein the end time estimating unit sets an end time for each port when the equipment allocated to the last process has a plurality of ports. The end time storage unit stores the end time for each port, and the processing time estimating unit, when a plurality of in-process lots arrive at the first step, processes each of the in-process lots Predicting time, the processing time storage unit stores the processing time for each in-process lot, the lot control unit determines the processing start time of each of the plurality of in-process lots, the plurality of in-process lots according to a predetermined standard A process control apparatus for selecting one of the in-process lots and instructing the start of processing of the selected in-process lot. 9. A process control device for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities, and constitutes at least a part of all processes performed in the production system. For an in-process lot in the last step of a continuous process, an end time prediction unit that predicts an end time in the last step, and an end time storage unit that stores the end time predicted by the end time prediction unit. A processing time storage unit that stores a predicted processing time prepared in advance from a first step of the continuous steps to a step immediately before the last step, and an end time stored in the end time storage unit And, from the estimated processing time stored in the processing time storage unit, determine the processing start time for the in-process lot in the first process, and after the elapse of the processing start time, the first Process control device being characterized in that a lot control unit for instructing to start processing of the in-process lots in extent to the corresponding equipment. 10. The process control device according to claim 9, wherein the processing time storage unit stores a plurality of predicted processing times prepared according to different conditions, and wherein the lot control unit stores A process control apparatus characterized in that when calculating a processing start time for an in-process lot in a process, an estimated processing time according to the in-process lot is used. 11. The process control device according to claim 9, wherein the end time predicting unit sets an end time for each port when the equipment allocated to the last process has a plurality of ports. The end time storage unit stores the end time for each port, and the lot control unit, when a plurality of in-process lots arrives at the first process, starts processing of each of the in-process lots A process control apparatus for obtaining a time, selecting one of the plurality of in-process lots according to a predetermined standard, and instructing to start processing the selected in-process lot. 12. The process control device according to claim 6, wherein the lot control unit does not pass through a facility in which the in-process lot performs the plurality of continuous processes without passing through a buffer. A process control device for instructing the start of processing of a work-in-process lot so as to be directly conveyed and processed. 13. The process control device according to claim 8, wherein the lot control unit selects a work-in-progress lot in an order of arrival at the first process, an order of processing start time, or a margin for a lot delivery date. A process control device, wherein the process control is performed based on degrees. 14. The process control device according to claim 6, wherein the end time prediction unit is based on a prediction material including at least information on the in-process lot itself and information on the corresponding equipment. The processing time prediction unit predicts the processing time based on a prediction material including at least information on the in-process lot itself, information on the corresponding equipment, and information on transportation. A process control device comprising: 15. The process control device according to claim 14, wherein each in-process lot carries information relating to itself, and further comprising means for reading the information. 16. The process control device according to claim 15, further comprising a sensor unit for detecting that the in-process lot has arrived at the first process, wherein the reading unit receives a signal from the sensor unit. A process control device for reading information on a work-in-progress lot, while using the information read by the reading means as one of the prediction materials while the processing time prediction unit is used. 17. The process control device according to claim 6, wherein the lot control unit instructs a start of processing on the in-process lot in the first process, and then executes the in-process lot. Wherein the end time of the last step used to determine the start of the process is discarded from the end time storage unit. 18. A computer system for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities, wherein a last step of a continuous process constituting at least a part of all processes performed in the production system is performed. Estimating the end time in the last step for the in-process lot in the step, storing the predicted end time in the end time storage unit, and in-process in the first step of the continuous steps. Estimating a processing time from the first step to a step immediately before the last step, storing the estimated processing time in a processing time storage unit, and the end time storage unit From the end time stored in the processing time and the processing time stored in the processing time storage unit, a processing start time for the in-process lot in the first process is obtained. And step, after the processing start time has elapsed, the first step in the in-process lot processing starts a corresponding computer-readable program recording medium recording a program for executing the steps on a computer that directs the facility. 19. A computer system for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities. Estimating the processing time from the first process to the process immediately before the last process of the continuous process for the in-process lot in the process, and storing the estimated processing time in the processing time storage unit Calculating the processing start time for the in-process lot in the first process from the data stored in the end time storage unit and the processing time stored in the processing time storage unit; Instructing the corresponding equipment to start processing the in-process lot in the first step after the processing start time has elapsed; and A program for causing a computer to execute a step of predicting an end time in the last step of the continuous steps for the in-process lot in the first step, and a step of storing the predicted end time in an end time storage unit A computer-readable program recording medium recording a program. 20. A computer system for controlling a lot flow of a production line in a production system in which a plurality of processes are performed by a plurality of facilities, wherein a last step of a continuous process constituting at least a part of all processes performed in the production system is performed. Estimating the end time in the last step for the in-process lot in the step, storing the predicted end time in the end time storage section, and predicting the end time stored in the end time storage section. Obtaining a processing start time for the in-process lot in the first process from a time and an estimated processing time stored in advance in the processing time storage unit; and Instructing the corresponding equipment to start processing the in-process lot in the computer. Possible program recording medium take. 21. The program recording medium according to claim 20, wherein a plurality of predicted processing times according to different conditions are stored in the processing time storage unit, and the step of obtaining the processing start time includes a process in process. A program recording medium, wherein one of the plurality of predicted processing times is used according to a lot. 22. The program recording medium according to claim 18, wherein in the step of predicting the end time, a facility assigned to the last step has a plurality of ports. In the step of predicting an end time for each port, and predicting the processing time, when a plurality of in-process lots arrive at the first process, predicting a processing time of each of the in-process lots, In the step of obtaining a start time, a process start time of each of the plurality of in-process lots is obtained. In the step of instructing the start of the process, one of the plurality of in-process lots is selected according to a predetermined standard. A program recording medium for instructing start of processing of a selected in-process lot.