JPH0435852A - Method and device for production control - Google Patents

Abstract

PURPOSE:To increase a processing efficiency in a specified stage, by fixing the time when a processing object is fed to a specified stage from the stage immediately before based on the result of an arrival time and the processing residual time in the specified stage being compared. CONSTITUTION:The residual time of the processing time of a specified stage 6 and the existence number of processing objects in each stages 5 prior to the specified stage 6 are detected. In the case of this detected residual time becoming a specific time, the existing number of the processing objects in the stage immediately before the specified stage is compared with the specific number and the arrival time of the processing object in the number short of the specific number from its existing stage to its arrival to the specified stage is calculated by a computor 2, in the case of the existence number being short of the specific number. This calculated arrival time and residual time are compared and the time when the processing object is fed out to the specified stage 6 from the stage 5 immediately before is fixed based on this comparison result.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for controlling production.

[Conventional technology]

In the diffusion processing process in a semiconductor production line that has multiple production processing steps, the processing target, the product group and the loft, which is the semi-finished product group, is processed in a diffusion furnace according to the processing conditions required. ing. A plurality of the diffusion furnaces are provided, and a plurality of types of lofts are processed in parallel.

Furthermore, each diffusion furnace is designed to simultaneously process a predetermined number of lofts in order to increase work efficiency.

The loft treated in such a diffusion treatment process is subjected to a predetermined chemical treatment in a chemical treatment process which is the process immediately before the loft, and then sent to the diffusion treatment process. For each loft, the necessary processing conditions in the diffusion furnace are determined in advance, and correspondingly, the processing conditions for each diffusion furnace are different. That is, the loft is subjected to diffusion treatment in a diffusion furnace under the same treatment conditions as the predetermined necessary treatment conditions. In a diffusion furnace,
In order to increase the processing efficiency, processing is waited until a predetermined number of lofts are available, and the processing is started every time a predetermined number of lofts are available.

However, if the loft sent to the diffusion treatment process is stored for a certain period of time from the completion of the chemical treatment to the start of the diffusion treatment, the surface will oxidize and become unsuitable for the diffusion treatment.
A feature is that the diffusion process must be started within the predetermined time.

For this reason, in the chemical treatment process, chemical treatment of the loft is started taking into account the empty state of the diffusion furnace in the diffusion treatment process so that the storage time of the loft waiting for treatment in the diffusion treatment process does not exceed a predetermined time. Later lots must be sent to the diffusion process as soon as possible.

Conventionally, the operator of the chemical treatment process predicted the treatment completion time of each diffusion furnace, and based on this prediction, chemically treated the required number of lofts and sent them to the diffusion treatment process.

However, when processing is performed based on the worker's predictions in this way, the predictions may be incorrect, and when the quantity of the next processing lot is less than the predetermined number, the loft quantity may be filled in a short time. In some cases, it may not be possible to determine whether or not the loft will be processed in a timely manner, so the lot may be placed on the waiting list for the chemical processing process even though it takes a long time to fill the loft quantity. There was a problem that the loft processing efficiency was not good because it was not always sent to the process.

Therefore, in order to improve the processing efficiency, a device as described below has been proposed (Japanese Patent Laid-Open No. 62-88558).
This method monitors the progress of the diffusion treatment in the diffusion treatment process, and determines the next treatment in the chemical treatment process from the diffusion treatment start time obtained by this monitoring and the diffusion treatment time and chemical treatment time given in advance. The processing start time of the loft is calculated, the chemical processing of the next processing lot is started according to the calculated processing start time, and the loft after the chemical processing is completed is sent to the diffusion processing step.

[Problems to be Solved by the Invention] However, the above-mentioned proposal calculates the treatment start time of the next treatment loft, and starts the chemical treatment of the next treatment loft at this treatment start time, thereby completing the diffusion treatment. It is supposed to start the chemical treatment of the next processing loft beforehand, but it does not mention how to decide when to send the next processing loft to the diffusion treatment process when the quantity of the next processing loft is less than a predetermined number. The problem was that there was no.

The present invention has been made to solve the above-mentioned problems, and the number of objects to be treated next in a specific chemical treatment step is greater than a predetermined number in the immediately preceding chemical treatment step. It is an object of the present invention to provide a production control method and apparatus for improving the processing efficiency in the specific process by determining the point of sending from the immediately preceding process to the specific process when there is a shortage.

[Means for Solving the Problems] The production control method according to the present invention includes the remaining processing time of a specific process in which a predetermined number of objects to be processed are collectively processed, and each process before the specific process. detecting the number of objects to be processed existing in the process, and when the detected remaining time reaches a predetermined time, comparing the number of objects to be processed in the process immediately before the specific process with the predetermined number; If the number of objects to be processed is less than the predetermined number, it is determined whether to wait until the number of objects to be processed reaches the predetermined number before sending the objects to the specific process. Calculate the arrival time for the object to arrive at the specific process from the process in which it exists, compare the calculated arrival time with the remaining time, and until the process in the specific process is completed based on this comparison It is determined whether the insufficient number of objects to be processed arrive at that process, and based on the result of the comparison, the processing from the immediately preceding process to the specific process is carried out efficiently. Manage production by determining the point at which the material to be processed is sent out.

The production control device according to the present invention includes means for detecting the remaining processing time of a specific process for collectively processing a predetermined number of objects to be processed, and means for detecting the number of objects to be processed in each process. , means for comparing the number of objects to be processed in a step immediately before the specific step with the predetermined number when the detected remaining time reaches a predetermined time; means for calculating the arrival time for the insufficient number of processing objects to arrive at the specific process from the process in which they exist, and the arrival time calculated by the means and the remaining time; and determining whether or not to wait until a predetermined number of objects to be processed are sent to the specific process based on the comparison result between the arrival time and the remaining time. The time point at which the object to be processed is sent from the immediately preceding step to a specific step is determined.

[Effect]

When the detected remaining time reaches a predetermined time, in a specific step of collectively processing a predetermined number of processing objects, the number of processing objects to be processed next in the immediately preceding step and the predetermined number of processing objects to be processed next are determined. By comparing the number of objects to be processed, it is possible to determine whether or not the number of objects to be processed next satisfies the number for which the batch processing can be performed, and if the number of objects to be processed is less than the predetermined number, Comparing the arrival time until the missing part of the processing object arrives at the specific process with the remaining time, it is determined whether the missing part of the processing object will arrive at the specific process during this remaining time. If it is possible to determine whether the object to be processed is insufficient and the insufficient amount of the object to be processed arrives at a specific process during the remaining time, the object to be processed is sent from the immediately preceding process to the specific process until the insufficient amount arrives. while waiting for
If the missing part of the processing object does not arrive at a specific process during the remaining time, if the missing part is sent from the previous process to the specific process without waiting for the missing part, the specific process will be more efficient. Objects to be processed can be processed.

[Examples] The present invention will be specifically described below based on drawings showing examples thereof. FIG. 1 is a block diagram showing the configuration of a production control device according to the present invention.

In the figure, 5 is a chemical treatment step in which a chemical treatment device 52 performs a predetermined chemical treatment on the loft, which is an object to be treated. The chemical treatment step 5 includes a chemical treatment device 52 that performs chemical treatment and a storage device 51 that stores a predetermined number of lofts to be treated by the chemical treatment device 52.
The loft is transported between the chemical processing equipment 52 and the transport vehicle 30.
It will be held at

The storage device 51 includes a storage section 51b for storing the loft and a management section 51a for managing the storage section 51b, which includes an IC card reading device. An IC card storing information such as processing conditions and loft numbers is attached to each lot, and the management section 51a reads the information from the IC card attached to each loft using the IC card reader. It looks like this. This allows the management section 51a to always know the number of lots stored and the processing conditions for each lot. Further, the chemical treatment device 52 includes a treatment section 52b for chemically treating the loft, and a control section 52a for controlling the treatment section 52b.

The loft chemically treated in the chemical treatment step 5 is sent to the diffusion treatment step 6. The diffusion treatment process consists of a plurality of diffusion furnaces 60, 60, . The diffusion furnace 60 is a processing section 6 that performs diffusion processing.
The processing section 60b is configured to simultaneously process a predetermined number of lofts under the same processing conditions.

In addition, 4.4... in the figure indicates a predetermined pre-process before the chemical treatment process 5, and the loft is sent to the chemical treatment process 5 through these pre-processes 4, 4... .

Transport of the loft between each process as described above is carried out by the transport vehicle 30.3.
0..., and transport vehicle 3
0.30... is driven by the transport control computer 3. The transport control computer 3 is connected to the production control computer 1, and controls the transport vehicles 30, 30, . . . in accordance with instructions given from the production control computer I.

In addition, the management section 51a of the storage device 51, the chemical processing device 52
The control unit 52a of the diffusion furnace 60, 60, and the control units 60a, 60a, . Storage condition of &51 and chemical processing equipment 52
The processing conditions of the diffusion furnaces 60, 60, and so on are managed by a production control computer. Each control section 60a, 60a... of the diffusion furnace 60, 60... measures the processing time in the processing section 60b, and requests the next processing loft when the remaining processing time of the loft reaches a predetermined time. A next processing loft request signal is given to the production control computer 1. In addition, the management section 51a of the storage device 51 of the chemical treatment process 5 and the management section 40a of the storage devices 40, 40, etc. of the preceding steps 4, 4... are responsible for the storage of lofts stored in each storage device. Information is given to the production control computer 1.

Connected to the production control computer 1 is an arrival time calculation computer 2 that calculates the time for the loft to arrive at the diffusion furnace 60, 60, . . . of the diffusion treatment process 6. The arrival time calculation computer 2 calculates the loft arrival time based on the data given from the production control computer 1, and provides the calculation result to the production control computer I. Further, a display device 7 made of a CRT is connected to the production control computer 1 for displaying information on the next processing lot. 51 management section 51a and pre-process 4.4...
Based on the information about the loft given from the management unit 40a of the storage device 40, 40..., the next processing lot in the chemical processing step 5 is determined by the method described below,
Information on the determined next processing loft is displayed on the display device 7.

In the production control device configured as described above, the loft is transported from a predetermined pre-process 4 to the storage device 51 of the chemical treatment process 5. The loft stored in the storage device 51 is transferred to the chemical processing device 5 by the transport vehicle 30 according to instructions from the production management computer 1.
2 and undergo chemical treatment. After the chemical treatment is completed, the loft is transferred to the diffusion furnace 60 in the diffusion treatment step 6 using the transport vehicle 30.
, 60 . . . and undergoes a diffusion process. However, from the storage device 51 to the chemical processing device f5
When sending lofts to the storage device 2, if multiple lofts of the same type are stored in the storage device 51, the production management computer 1 assigns processing priority to the storage device 51 based on the order of arrival at the storage device 51, etc. The next processing loft is sent accordingly.

Next, a method for determining the next treatment loft in chemical treatment step 5 will be explained. FIG. 2 is a flowchart showing the procedure for determining the next processing lot in chemical processing step 5. When determining the next processing loft, first, the diffusion furnace 60.60.
..., the next processing loft request signal is sent to the production control computer.
(Step 1).

If the next processing loft request signal is given, whether or not a loft with the same processing conditions as the processing conditions of the diffusion furnace 60, 60... from which the next processing loft request signal was sent is stored in the storage device 51. (Step 2).

When a lot with the same processing conditions as the processing conditions of the diffusion furnace 60, 60... is stored in the storage device 51, the loft of the processing condition is set for each diffusion furnace 60, 60... Determine whether there are more than the number of processes (Step 3)
.

If the number of lofts is equal to or greater than the set processing number, select a loft corresponding to the set processing number according to the priority order as described above (Step 4), and display the selected loft number on the display device 7 (
Step 5).

In step 3, if the number of lofts is less than the set processing number, the loft storage information given to the production control computer 1 from the previous process 4 is given to the arrival time calculation calculator 2, and the arrival time calculation calculator 2 The location of the missing loft (
The arrival time required for the loft to arrive at the diffusion furnaces 60, 60, . . . from the existing position is calculated (step 6). When calculating the arrival time, the processing time, transport time, and loft in the process from the location of the loft to the diffusion furnace 60, 60... are calculated from the transport vehicle 30 (or each device) to each device (or transport vehicle 3
0) to obtain the arrival time.

The calculated arrival time is then applied to a specific diffusion furnace 60.
Determine whether or not the time from when the next processing loft request signal is transmitted from 60... until the processing in the diffusion furnace 60 is completed (hereinafter referred to as remaining time) is shorter. (Step 7).

If the arrival time is shorter than the remaining time, the diffusion furnace 6
This indicates that the desired loft arrives at the diffusion furnace 60.60... before the processing of 0.60... is completed, and in this case, the priority of processing of the desired loft in each process is increased. After processing (step 8), return to step 1 and repeat the above-described processing until the loft arrives at the storage device 51.

On the other hand, if the arrival time is longer than the remaining time in step 7, this indicates that the desired loft will arrive at the diffusion furnace 60, 60... after the processing in the diffusion furnace 60, 60... is completed. If you wait until the loft arrives, the processing efficiency of the diffusion furnace 60, 60... will decrease, so check whether the number of lots existing in the storage device 51 at that point is the number of lofts that can be processed at closeout. Determine (step 9). The number of lofts that can be processed at the end of each diffusion furnace 6
Each is predetermined based on the specifications of 0.60...

If the number of lofts is such that the number of lofts that can be processed is large enough, an instruction to perform the processing is displayed on the display device 7 (step 1).
0).

The next processing lot determined by the processing described above is
After receiving instructions from the production management computer 1 and controlling the transport control computer 3, it is sent to the chemical processing device 52 by a transport vehicle. In this way, the lots in the storage device 51 are sent from the chemical treatment device 52 to the diffusion treatment step 6 according to the treatment status in each step before the chemical treatment step 5.

In this embodiment, an example is shown in which the transportation of the loft is automated, but if the transportation is not automated, the transportation and processing may be carried out by the operator according to the display on the display device 7.

〔Effect of the invention〕

The present invention is as described above, and when the number of processing objects to be sent to a specific process is less than a predetermined number in the immediately preceding process, the insufficient number of processing objects are transferred from the process where the processing object exists. The arrival time until arriving at a specific process is calculated, and the processing target is transferred from the immediately previous process to the specific process based on the result of comparing the calculated arrival time and the remaining processing time in the specific process. In order to determine the sending point 7, the processing object is sent from the immediately preceding process to a specific process according to the distribution situation of the processing object in the process before the immediately preceding process, so that the processing efficiency in the specific process is The present invention has excellent effects such as being able to improve.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a production control apparatus according to the present invention, and FIG. 2 is a flowchart showing a procedure for determining a next processing loft in a chemical processing process. 1... Production control computer 2... Arrival time calculation calculator 5... Chemical treatment process 6... Diffusion treatment process 40a... Management department 51a... Management department 60
a...Control unit In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) Production on a production line that is equipped with multiple processes that sequentially perform production processing on objects to be processed, and in which a predetermined number of objects are processed at once in a specific process. In the management method, the remaining processing time of the specific step and the number of objects to be processed in each step before the specific step are detected, and when the detected remaining time reaches a predetermined time, , the number of objects to be processed in the process immediately preceding the specific step is compared with the predetermined number, and if the number of objects to be processed is less than the predetermined number, the insufficient number of objects to be processed are Calculate the arrival time from the existing process to the specific process, compare the calculated arrival time with the remaining time, and change the processing target from the previous process to the specific process based on the comparison result. A production control method characterized by determining the point in time when things are sent out. (2) Production on a production line that is equipped with multiple processes that sequentially perform production processing on objects to be processed, and in which a certain number of objects are processed at once in a specific process. In the managing device, means for detecting the remaining processing time of the specific step; means for detecting the number of objects to be processed in each step before the specific step; and the detected remaining time. means for comparing the number of objects to be processed in the step immediately before the specific step with the predetermined number when a predetermined time has elapsed; means for calculating the arrival time for the insufficient number of processing objects to arrive at the specific step from the step in which they exist; and means for comparing the arrival time calculated by the means with the remaining time; A production control device characterized in that the time point at which the object to be processed is sent from the immediately preceding step to a specific step is determined based on the comparison result.