JP2012076891A - Cassette conveyance priority allocating method and cassette conveyance control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cassette conveyance priority allocating method for conveying a cassette by enhancing conveyance priority in a process of stopping a cassette input into a loader, and on the contrary, delaying a conveyance instruction to a process having a margin.SOLUTION: In the cassette conveyance priority allocating method, the number of existing substrates per buffer device belonging to the loader, and an index time being a preregistered time interval for delivering a substrate to a downstream device from a loader per each loader are monitored to calculate a time until all substrates in the buffer device are delivered by each loader, the shortest time necessary for delivering a substrate to the downstream device of the loader from conveyance starting of a cassette from a stocker facility is calculated in regard to each cassette, and after completing an input to the downstream device from the loader when conveyance is started, a time of stopping the input is calculated in regard to each cassette, and conveyance priority is allocated in an order from a cassette with a longer time of stopping the input.

Description

  The present invention relates to a cassette transport control system that transports and controls a cassette that houses a glass substrate in a color filter manufacturing process, a liquid crystal display manufacturing process, and a semiconductor manufacturing process.

  A color filter substrate will be described as an example of a glass substrate (hereinafter referred to as a substrate) used in a color filter manufacturing process, a liquid crystal display device manufacturing process, and a semiconductor manufacturing process.

  FIG. 1 is a cross-sectional view of a color filter substrate used in a color liquid crystal display device as an example of a substrate. The color filter 1 includes a black matrix (hereinafter referred to as BM) 3, a red R colored pixel (hereinafter referred to as R pixel) 4-1, a green G colored pixel (hereinafter referred to as G pixel) 4-2, and a blue B on the substrate 2. The colored pixels (hereinafter referred to as B pixels) 4-3, the transparent electrode 5, the photo spacer (hereinafter referred to as PS) 6, and the vertical alignment (hereinafter referred to as VA) 7 are sequentially formed. is there.

  As a method for manufacturing a color filter having the above structure, a photolithography method, a printing method, and an ink jet method are known. FIG. 2 is a flowchart showing steps of a commonly used photolithography method. The color filter is first formed by a process of forming BM on the substrate (K1), a process of cleaning the substrate (K2), a process of applying and pre-drying a colored photoresist (K3), drying the colored photoresist, A pre-bake process (K4) for performing a curing process, a process (K5) for performing an exposure process, a process (K6) for performing a developing process, a process (K7) for curing a colored photoresist, and a transparent electrode (for example, ITO (Indium Tin Oxide)) are formed. A film processing step (K8) and a PS and VA forming step (K9) are performed in this order to manufacture.

  For example, when pixels are formed in the order of R pixel, G pixel, and B pixel, red R is applied between the process of cleaning the color filter substrate (K2) and the process of curing the colored photoresist (K7). The color resist is changed in the order of green G and blue B, and the process is repeated three times to form R pixels, G pixels, and B pixels.

  FIG. 3 is a diagram schematically showing an arrangement example of apparatuses and facilities in each process in the manufacturing process of the color filter. In the manufacturing process shown in FIG. 3, the substrate processed in each line (process) is collected in a cassette and carried to the next process. For example, the substrate processed in step A of FIG. 3 is temporarily stored in the stocker and then transferred to step B 11 of the next step, where the substrates are sequentially discharged from the cassette. At this time, a substrate discharged from a loader (hereinafter referred to as LD) device 12 serving as an input device is alternately discharged to a buffer (hereinafter referred to as BF) device 13 and a downstream device (processing device in the B process 11). By alternately discharging the substrates, the substrates can be stored in the BF device 13 while supplying the substrates downstream. The cassette can be replaced without stopping the loading from the LD device 12 by replacing the cassette while the stored substrates are being dispensed.

In addition, the stocker management system determines whether the cassette is transported from the stocker to the input device for each process. The stocker management system determines whether the cassette can be transported by managing the status of the cassette in the stocker and the state of the transport device in the stocker. The stocker facility supplies the cassette to the loader device in one of the processes in accordance with the conveyance instruction issued from the stocker management system. At this time, if there are two or more unprocessed transport instructions in the stocker facility,
The stocker equipment processes the transport instructions sequentially from the old transport instructions.

JP 2004-109968 A

  As for the timing of transporting the cassette to the LD device, it is desirable that the cassette is transported to the LD device with the substrate remaining in the BF device attached to the LD device, but the stocker facility issues a transport instruction to the cassette. Carry out in order. As a result, a cassette may arrive before a line that does not have a line even if it has many devices in the BF apparatus. In such a case, there is a possibility that the cassette supply to the BF apparatus that needs the cassette supply immediately will be processed later, which causes the substrate loading to stop in the processing process. As a result, the process operating rate decreases and the productivity deteriorates.

  Therefore, in view of the above problems, the present invention assigns a transport priority to the transport instruction for all cassettes, thereby stopping the insertion of the cassette into the LD apparatus even though the stocker has a work in progress. An object of the present invention is to provide a cassette transport priority distribution method and a cassette transport control system for transporting a cassette with a higher transport priority and conversely with a transport instruction for a process having a margin.

The invention according to claim 1 of the present invention provides a loader provided at the entrance of a plurality of substrate processing steps from a stacker facility for storing a cassette in which substrates are stored in a production line including a plurality of processing steps for processing substrates. A cassette transport priority distribution method for determining the transport order for each cassette when transporting cassettes to the apparatus,
Monitor the number of substrates present for each buffer device attached to the loader device, and an index time that is a pre-registered time interval for dispensing the substrate from the loader device to the downstream device for each loader device,
Calculate the time until each loader unit pays out all the substrates in the buffer unit, and
For each cassette, calculate the shortest time required from the start of conveyance of the cassette from the stocker facility to the delivery of the substrate to the downstream device of the loader device,
For each cassette, calculate the time to stop loading after the loading from the loader device to the downstream device is completed when transport is started,
The cassette transport priority distribution method is characterized in that transport priorities are distributed in order from the cassette having the longest stoppage time.

  In the invention according to claim 2 of the present invention, the time until each loader device pays out all the substrates in the buffer device is the number of substrates existing for each buffer device attached to the loader device, and for each loader device. 2. The cassette transport priority distribution method according to claim 1, wherein the calculation is performed by multiplying the index time, which is a time interval for delivering the substrate from the loader device to the downstream device.

  In the invention according to claim 3 of the present invention, the shortest time required from the start of conveyance until the substrate is discharged to the downstream device of the loader device is the time required to complete the conveyance from the stocker facility to the loader device, and before the loading. The cassette transport priority distribution method according to claim 1, wherein the calculation is performed by adding the necessary time.

In the invention according to claim 4 of the present invention, when the conveyance of each of the cassettes is started, after the loading from the loader device to the downstream device is completed, the loading stop time is from the start of the conveyance to the downstream of the loader device. 4. The cassette transport priority according to claim 1, wherein the cassette transport priority is calculated by subtracting a time until all substrates in the buffer device are dispensed from a minimum time required until the substrates are dispensed to the apparatus. This is a distribution method.

  In the invention according to claim 5 of the present invention, when a low priority cassette has arrived at a transfer device that transfers a high priority cassette, the maximum transfer time of the high priority cassette is the substrate of the buffer device. The cassette transport priority distribution method according to any one of claims 1 to 4, wherein when the payout completion time is shorter, a cassette having a low priority is transported preferentially.

  The invention according to claim 6 of the present invention is a cassette transport control system that controls the transport of cassettes using the cassette transport priority distribution method according to any one of claims 1 to 5.

  According to the cassette transfer priority distribution method and the cassette transfer control system according to the present invention, transfer priority of all cassettes can be assigned to all cassettes according to the situation of each process, and as a result, each process The load stoppage time of the loader device at the time is reduced, and it becomes possible to improve the operation rate of each processing step and the stacker equipment.

The figure which showed an example of the color filter used for a color liquid crystal display device in a cross section. The processing line flow figure of the photolithographic method generally used. The figure which showed typically the example of arrangement | positioning of the apparatus and installation of each process in the manufacturing process of a color filter. The figure which shows the structural example of the apparatus and installation of a manufacturing process to which the cassette conveyance control system of this invention is applied. The example of implementation environment of this invention is shown. The flowchart of the cassette conveyance priority allocation which concerns on the cassette conveyance control system of this invention. The figure for demonstrating the conveyance order in the case of the example of a conveyance pattern in which the cassette of conveyance priority 2 arrived at CV (1) ahead of the cassette of conveyance priority 1.

  Hereinafter, an embodiment for carrying out the cassette conveyance control system of the present invention will be described with reference to the drawings, taking a color filter manufacturing process as an example.

  FIG. 4 is a diagram showing a configuration example of an apparatus and equipment in a manufacturing process to which the cassette conveyance control system of the present invention is applied. The manufacturing process shown in FIG. 4 includes processes from A process to F process, and the LD apparatus in each process alternately delivers the substrate from the cassette to the process and the BF apparatus. In the stockers (1) to (3), cassettes storing substrates to be delivered to the process are stored, and the cassettes are arranged in the order in which the transport priority is determined by the cassette transport control system. (2) and RB (robot) (1) to (3) are conveyed to the LD apparatus in any of the steps A to F.

FIG. 5 shows an example of an implementation environment of the present invention. The transfer control system 30 according to the present invention includes a controller (ie, PLC: programmable logic) of processing equipment in each process indicated by 14 to 23, LD equipment, BF equipment, ULD (unloader) equipment, and equipment in stockers such as RB and CV. controller) and the transport control unit 31 are connected via a local area network (LAN) 32 constructed by Ethernet (registered trademark), and each facility and the transport control unit according to communication standards such as TCP / IP and UDP / IP. Data is transmitted / received between them. Under such a network environment, information to be managed between each other is transmitted and received between the transport control unit 31 and each of the facilities 14 to 23, thereby realizing cassette transport control. The conveyance control unit 31 receives a signal via a network, holds the received information as data in a database (hereinafter referred to as DB), and distributes the conveyance priority of the cassette to be conveyed based on the DB.

  Using the equipment configuration shown in FIG. 4, the flow of assigning cassette transport priority according to the cassette transport control system of the present invention will be described using the flowchart of FIG. 6.

Step (S1)
The conveyance control unit provided in the cassette conveyance control system always monitors the number of substrates stored in the BF attached to the LD port in the A process to the F process.
The number of stored BFs in each process is determined as follows.
Number of BF stored in process A ・ ・ ・ BFcnt (A)
Number of BFs stored in process B ・ ・ ・ BFcnt (B)
Number of BFs stored in process C: BFcnt (C)
Number of BF stored in D process ・ ・ ・ BFcnt (D)
Number of BF stored in E process ・ ・ ・ BFcnt (E)
Number of BF stored in F process ・ ・ ・ BFcnt (F)

Step (S2)
The transport control unit monitors the index time of each LD device (time interval for delivering the substrate from the LD to the downstream device: a set value, which is registered in the transport control unit 31 in advance).
The LD device index time for each process is determined as follows.
LD device index time for process A ・ ・ ・ LDidx (A)
LD device index time for process A ... LDidx (B)
LD device index time for process C ・ ・ ・ LDidx (C)
LD equipment index time of D process ・ ・ ・ LDidx (D)
LD equipment index time of E process ・ ・ ・ LDidx (E)
LD process index time of F process ・ ・ ・ LDidx (F)

Step (S3)
The transfer control unit calculates a time (substrate discharge completion time) until all the substrates in the BF in each step are discharged.
The time until the BF device substrate payout in each step is completed is determined as follows.
Time until BF device substrate payout in each process is completed.
... Etim (*) = BFcnt (*) × LDidx (*)
Here, (*) represents each step of A to F.
The data of step (S1) to step (S3) is stored in table 1 shown in Table 1.

  Table 1 shows the equipment ID indicating the equipment-specific identification ID, the number of stored sheets in the BF apparatus indicating the number of boards in the BF apparatus, the index time indicating the time interval to be paid out from the LD apparatus to the downstream apparatus, and all the numbers in the BF apparatus. A loading completion time indicating the time until the loading of the substrate is completed is included.

Step (S4)
The transport control unit manages the information in Table 2 shown in Table 2 in units of cassettes, and calculates the time required from the start of transport to the delivery of the substrate to the downstream device of the LD device.
Transfer completion time: Txfr (represents the shortest time until transfer is completed)
Time required for loading: Tinp
Minimum time from transfer start to substrate loading: Tmin = Txfr + Tinp

  Table 2 shows a cassette ID indicating an identification ID unique to the cassette, a transfer completion time indicating a time taken to transfer to the target LD apparatus, and a transport delay indicating a waiting time that occurs when other cassettes are preferentially processed. It includes a time, a required input time indicating the time required from the arrival of the cassette to the downstream device from the LD apparatus, and a transport priority indicating the transport priority specific to the cassette.

Step (S5)
The conveyance control unit calculates the time for each cassette to stop loading from the LD apparatus to the downstream apparatus when conveyance is started.
Input stop time: Tmin−Etim (*) = Tstp
Here, Tstp is managed in cassette units.

Step (S6)
The transport control unit assigns values having higher transport priority in descending order of Tstp.
As for the transport priority, 1 is the highest value, and the priority is given to the lowest value in order. The minimum value depends on the number of cassettes (the minimum value when there are 5 cassettes is 5). When transport is started, the priority is fixed with respect to the cassette, and the priority does not change during transport.

Step (S7)
The conveyance control unit transmits cassette conveyance priority information to the stocker facility at a timing when a conveyance instruction is issued to each cassette. Table 3 shows the information to be transmitted.

  The transmission information shown in Table 3 includes a cassette ID indicating a cassette-specific identification ID, a transport priority indicating a cassette-specific priority, a transport source ID indicating a transport source device ID, and a transport destination ID indicating a transport destination device ID. Is included.

  As described above, the transport control unit provided in the transport control system assigns a value having a higher transport priority in descending order of the loading stop time (Tstp) for all cassettes.

Step (S8)
When there are two or more transport instructions waiting for transport, the stocker equipment sequentially transports from the highest priority.

  As described above, the conveyance of the cassette is started in descending order of the conveyance priority. In the case of the conveyance pattern example of FIG. 7, the system determines which cassette is conveyed first. That is, in the case of the transport pattern example shown in FIG. 7, the cassette with transport priority 2 arrives at CV (1) before the cassette with transport priority 1, but when CV (1) is used, the cassette with transport priority 1 is reached. Since the conveyance time of the cassette is delayed, when only one cassette can be placed in the CV (1) connecting the stockers, the conveyance control system performs the following control to improve the operation rate of the equipment in the stocker.

The conveyance control unit manages the following information in Table 3 shown in Table 4.
Transfer completion time: Txfr (represents the shortest time until transfer is completed)
Transport delay time: Tdel
Time required for loading: Tinp
Minimum time from transfer start to substrate loading: Tmin = Txfr + Tinp
The maximum transport time, Tmax, obtained by adding the delayed time to Tmin

  Table 4 shows the cassette ID indicating the identification ID unique to the cassette, the transfer completion time indicating the time required to transfer the cassette to the target LD apparatus, and the waiting time that occurs when other cassettes are processed preferentially. It includes a transport delay time, a required loading time indicating the time required from the arrival of the cassette to the downstream device from the LD apparatus, and a transport priority indicating the transport priority specific to the cassette.

  The conveyance control unit determines which of the two conveyances has priority by the following control.

That is,
(1) Maximum transport time: Tmax <Time until completion of substrate discharge of BF apparatus: Etim (*) When a cassette with a low priority is transported preferentially.
(2) Maximum transport time: Tmax> Time until completion of substrate discharge of BF apparatus: Etim (*) When a cassette with high priority is transported preferentially.
In this case, Etim (*) indicates the substrate discharge completion time of the BF device to which the higher priority cassette is loaded when two transports overlap.

  As described above, in the case of the conveyance pattern example shown in FIG. 7, it is determined whether or not the cassette having a low priority is to be preferentially conveyed.

  In addition, although the color filter substrate was illustrated as the form for implementing this invention, it is not limited to a color filter substrate, this invention is a cassette which accommodates the board | substrate under construction in a color filter manufacturing line and a semiconductor manufacturing line widely. Applicable when transporting.

  As described above, according to the cassette transport priority distribution method and the cassette transport control system of the present invention, it becomes possible to assign the priority order to each cassette to be transported. By shortening the stop time of the apparatus, it is possible to improve the availability of the stocker facility and the in-process apparatus.

DESCRIPTION OF SYMBOLS 1 ... Color filter 2 ... Substrate 3 ... Black matrix (BM)
4-1 ... Red R colored pixels (R pixels)
4-2 ... Green G coloring pixel (G pixel)
4-3 ... Blue B colored pixels (B pixels)
5 ... Transparent electrode 6 ... Photospacer (PS)
7 ... Vertical alignment (VA)
DESCRIPTION OF SYMBOLS 10 ... A process 11 ... B process 12 ... LD (loader) apparatus 13 ... BF (buffer) apparatus 14-23 ... Controller 30 ... Conveyance control system 31 ... Conveyance control Part 32 ... Local area network

Claims (6)

In a production line consisting of a plurality of processing steps for processing a substrate, when the cassette is transported from a stacker facility for storing a cassette in which the substrate is stored to a loader device provided at the entrance of the plurality of substrate processing steps, A method for assigning the priority of cassette transport to determine the transport order.
Monitor the number of substrates present for each buffer device attached to the loader device, and an index time that is a pre-registered time interval for dispensing the substrate from the loader device to the downstream device for each loader device,
Calculate the time until each loader device pays out all the substrates in the buffer device, and
For each cassette, calculate the shortest time required from the start of conveyance of the cassette from the stocker facility to the delivery of the substrate to the downstream device of the loader device,
For each cassette, calculate the time to stop loading after the loading from the loader device to the downstream device is completed when transport is started,
2. A cassette transport priority sorting method, wherein transport priorities are sorted in order from the cassette having the longest stoppage time.   The time required for each loader device to pay out all the substrates in the buffer device is the number of substrates existing for each buffer device attached to the loader device, and the substrate is discharged from the loader device to the downstream device for each loader device. The cassette transport priority distribution method according to claim 1, wherein the calculation is performed by multiplying an index time which is a time interval.   The shortest time required from the start of transfer to the time when the substrate is discharged to the downstream device of the loader device is calculated by adding the time required for transfer from the stocker facility to the loader device and the time required for loading. 2. The cassette transport priority distribution method according to claim 1, wherein:   When the transfer of each cassette is started, the time for the loading to stop after the loading from the loader device to the downstream device is completed is the shortest time required from the start of the conveyance to the delivery of the substrate to the downstream device of the loader device. 4. The method according to claim 1, further comprising subtracting a time until all substrates in the buffer device are dispensed from the time.   When a cassette with a low priority has arrived at a transport device that transports a cassette with a high priority, if the maximum transport time of the cassette with a high priority is shorter than the substrate discharge completion time of the buffer device, the priority is 5. The cassette transport priority distribution method according to claim 1, wherein a low cassette is transported preferentially.   A cassette transportation control system that controls the transportation of cassettes using the cassette transportation priority distribution method according to claim 1.