JP2007189147A - Conveyance system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveyance system capable of switching sheet conveyance and piling one, according to the situation of a processing device side by providing the sheet conveyance for conveying trays for stacking substrates one by one and a section for piling them up, and freely conveying trays in a conveyance path in the process of a liquid crystal substrate, or the like. <P>SOLUTION: The conveyance system 2 comprises pieces of breaking apparatus 12, 22 for breaking trays for placing works; stacking apparatus 14, 24 for piling up the trays; a conveyor 19 for conveying the trays between the pieces of dispensing apparatus 12, 22, and the stacking apparatus and supplying works to the processing device 4; and control means 34, 36 for changing the conveyance format, by changing the number of piled trays supplied from the dispensing apparatus 12, 22 to the conveyor 19. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transport system using a tray.

  The applicant studied to transport a large substrate such as a glass substrate for liquid crystal or an EL substrate or a work such as a semiconductor wafer on a tray. The applicant proposed in Patent Document 1 a tray structure that allows easy stacking and easy loading and unloading of workpieces. In addition, the applicant proposed in Patent Document 2 a stacking / stacking device that stacks and stores the trays and can stack the stacked trays one by one and stacks the trays that have been transported. .

The applicant then reached the present invention by paying attention to the fact that the optimum conveyance mode changes during the period from the start of production of a work such as a liquid crystal panel to the time when the process is stabilized.
JP 2005-93585 A JP 2005-89048 A

An object of the present invention is to enable a workpiece to be supplied to a processing apparatus at an appropriate timing by changing a conveyance form according to a situation.
An additional problem in the invention of claim 3 is to enable the workpiece to be conveyed in an optimum conveyance form according to the situation on the processing apparatus side.
An additional problem in the invention of claim 4 is that, when stacking and transporting, the vibration of the tray and the load on the conveyor are reduced, and the transport speed according to the tray spreading time on the processing apparatus side is set. The purpose of conveying the leaves is to enable the individual trays to be conveyed at high speed.

  The transport system according to the present invention includes a stacking device that stacks a tray on which a workpiece is placed, a stacking device that stacks the trays, and a tray that transports the tray between the stacking device and the stacking device to the processing device. And a control means for changing the conveying form by changing the number of stacked trays supplied from the leveling device to the conveyor. The change range of the conveyance mode is not limited to between the stacked conveyance and the single-sheet conveyance for each tray, and for example, the number of stacked sheets may be changed to 12 or 6 sheets.

Preferably, the control unit changes the conveyance mode between single-wafer conveyance for conveying the trays one by one and stacked conveyance for laminating and conveying a plurality of trays.
Also preferably, the control means changes the transport mode according to the operating status of the processing apparatus.

  Preferably, another stacking / stacking device is provided at the connection portion between the processing apparatus side and the conveyor, and the conveying speed of the conveyor is low when the number of stacked sheets is large, and high when the number of stacked sheets is small. Change to In this stacking / stacking device, one device for stacking / stacking may be provided between the conveyor and the processing device, or the stacking device and the stacking device may be provided separately.

  In this invention, a conveyance form is changed according to a condition, and a workpiece | work is supplied to a processing apparatus at a suitable timing. In particular, when switching between stack conveyance and single-wafer conveyance, it is possible to convey in a large conveyance unit so that some stock is generated on the processing apparatus side in the multilayer conveyance, and only necessary workpieces can be conveyed at a necessary time in single-wafer conveyance. If the transport mode is changed by changing the number of stacked layers, this intermediate effect can be obtained.

On the processor side,
・ The stage where the processing speed is slow and only a small amount of work is required,
・ The processing speed is slightly faster but the process is unstable and requires a buffer.
-Since the processing speed is fast and the time required for processing is stable, it is important to reduce the trays and workpieces held as buffers and supply only the necessary workpieces at the required time,
There are various situations. Therefore, the transfer mode is changed according to the situation on the processing apparatus side, and the workpiece is supplied to the processing apparatus in the optimal transfer mode.

  In the stacked transport, vibrations of the stacked trays and the load on the conveyor become problems, and the processing apparatus side needs to stack and stack the stacked transported trays. Therefore, the conveyor conveys at a low speed when the number of laminated sheets is large, and conveys at a high speed when the number of laminated sheets is small so as to meet the requirements of the processing apparatus.

  In the following, an optimum embodiment for carrying out the present invention will be shown.

  The conveyance system 2 of an Example is shown in FIGS. In the figure, reference numeral 4 denotes a processing apparatus, which is a processing apparatus such as a liquid crystal panel, an EL panel, or a semiconductor. The transport system 2 transports a work such as a liquid crystal panel or EL glass substrate or a semiconductor wafer to the processing apparatus 4. . A plurality of processing apparatuses 4 constitute one process as a whole, that is, a bay, and 6 is a stacker crane that performs long-distance conveyance between processes. 8 is the running rail, and 10 is a rack. Long distance conveyance is not limited to the stacker crane 6 and may be performed by a long distance conveyor or the like.

  The rack 10 is provided with a stacking device 12 and a stacking device 14. The stacking device 12 stacks the trays stacked and transported from the stacker crane 6 to a predetermined number of sheets and supplies the trays to the in-process transport conveyor 16. . Further, a stacking device 14 is provided at the end point of the in-process transport conveyor 16, and the trays transported by single sheets or stacked are further stacked and supplied to the stacker crane 6. When the trays stacked by the stacker crane 6 are stored in a cassette and transported, the stacking device 12 performs removal and stacking from the cassette, and the stacking device 14 stacks the cassette.

  The conveyance of the workpiece | work between the in-process conveyance conveyor 16 and the processing apparatus 4 is demonstrated. For example, a cutting device such as a conversion conveyor 18 is provided in the in-process transfer conveyor 16 to change the transfer direction of a required tray or a stacked body thereof, and is supplied to the leveling device 22 on the processing apparatus 4 side via the conveyor 19. The stacking device 22 stacks and stores a plurality of trays, cuts out an arbitrary required tray, and supplies it to the workpiece picking device 26 side. The tray and the work are separated by the take-out device 26, the tray and the work are separately conveyed by the two-stage conveyor 32, the work is taken in and out of the processing device 4 by the load port 28, and an empty tray is obtained by the placement device 30. The tray carried out from the processing device 4 is placed. Then, the trays are stacked by the stacking device 24, and at the time of stacking and transporting, the stacking order of the trays is controlled and the trays having the same transport destination are stacked together.

  The hatched conveyors 16 and 19 in FIG. 1 are sections in which the tray transport mode can be changed. The tray transport mode is referred to as single-sheet transport, and the stack transport is referred to as stacked transport. Between the stacking device 22 and the stacking device 24 is fixed to the sheet conveyance. The switching of the conveyance mode is not limited to between the lamination conveyance and the single wafer conveyance, and the number of laminations may be changed to, for example, 12 sheets and 6 sheets in the lamination conveyance. In addition, the section in which the tray transport mode is changed is not limited to the conveyors 16 and 19, but the transport mode may be changed on the stacker crane 6, for example.

  34 is an in-process conveyance controller that controls in-process conveyance from the stacking device 12 to the stacking device 14, and in particular, in the case of stack conveyance, the distinction between single wafer conveyance and stacked conveyance with respect to the separation device 12, Specify the number of trays to be stacked. Similarly, the distinction between the single wafer conveyance and the lamination conveyance and the number of lamination in the case of the lamination conveyance are designated to the stacking device 22 and the stacking devices 24 and 14. Further, the controller 34 designates the conveying speeds for the conveyors 16 and 19 and the conversion conveyor 18 so as to achieve the highest speed in the sheet-by-sheet conveyance, and decreases the conveying speed every time the number of stacked sheets is increased.

  The in-process transfer controller 34 receives a transfer command from the higher-level distribution controller 36, and is instructed from the distribution controller 36 to distinguish between single-sheet transfer or stacked transfer and the number of stacked sheets in the stacked transfer. Since the distribution controller 36 receives a work carry-in request and a carry-out request to the processing apparatus from a production controller (not shown) or the like, the physical distribution controller 36 grasps the work carry amount. Further, since an ID is added to each workpiece and a conveyance request with an ID is received, it is grasped whether or not the processing time from when the workpiece is loaded into the processing apparatus to when it is unloaded is stable. In other words, it is monitored whether or not the processing time from the loading of the workpiece to the unloading varies greatly due to a trouble in the processing device 4 or the like. Also, the amount of work carried in and out of each processing device 4 per time is known to the physical distribution controller 36. The amount of work carried in and the amount carried out are the same except for the buffer amount in the processing device 4, and the process is unstable when the amount carried in and the amount carried out per hour fluctuate significantly. In addition, the process becomes stable when the change in the amount carried in and the amount carried out becomes small, and the production maturity curve is entered.

  Therefore, the distribution controller 36 switches the transport mode according to the situation such as the start-up of the liquid crystal panel factory, the change of the product type, the change of the process due to the addition of the processing device, or the like. Specifically, since the transport amount is small when the factory is started up, when the process is changed, or when the product type is changed, in principle, single-wafer transport is used. Next, when the start-up stage is completed and the transport amount increases, the stacking transport is changed. At this stage, the process is unstable, and there is a possibility that the process on the post-process side cannot be performed due to a trouble of the processing apparatus 4 or the like. Therefore, in order to have as much inventory as possible for each processing apparatus 4, the stacked conveyance is selected. The stacked and transported trays are temporarily stored by the stacking device 22 and the stacking device 24.

  When the process becomes stable and the processing time in each processing device 4 can be predicted, or the temporal variation of the throughput of each processing device 4 becomes small, switching from stack conveyance to, for example, single wafer conveyance, or stacking by stack conveyance Reduce the number. Along with this, the conveying speed of the conveyors 16, 18, 19 is increased. At this stage, each processing device 4 can process according to the schedule, so there is no need to increase the inventory. Therefore, the work supplied to each processing device 4 is immediately supplied to the load port 28 without being stocked in the separating device 22, and the processed work is immediately taken out without being stored in the stacking device 24. Then, when a processed workpiece is unloaded from the load port 28, the next workpiece can be loaded immediately. Therefore, when the process is stabilized, the stacking conveyance is switched to the single wafer conveyance, and this determination is made by, for example, the distribution controller 36.

  FIG. 2 shows the leveling device 22 used in the embodiment, but the other leveling devices 12 and the stacking devices 14 and 24 have the same structure. 40 is a lifting platform, here a pantograph mechanism is used, and 42 is a chuck, which is not shown in the figure, provided in parallel in the height direction so that the tray group 46 can be chucked at a plurality of height positions. To. Reference numeral 44 denotes a tray, and a plurality of stacked trays is called a tray group 46, 48. The tray group 46 is supported on the upper side by the chuck 42, and the tray group 48 is supported by the lifting platform 40. The height position of the lower portion of the tray group 46 is controlled depending on whether a plurality of chucks 42 are selected. Reference numerals 50 and 52 denote exit / retreat conveyors, for example, which move up and down in the vertical direction of FIG. 2 to support and convey the bottom surface of the flange around the tray 44 when ascending, and separate from the tray 44 when descending. The exit / retreat conveyors 50 and 52 include, for example, roller conveyors, and the exit / retreat conveyor 50 conveys the tray 44 toward the take-out device 26, and the exit / retreat conveyor 52 conveys the tray 44 to and from the conveyor 19.

  The leveling device 22 can be leveled so as to cut out an arbitrary number of trays at an arbitrary height position from the stacked tray group. At the time of separation, for example, the lifting platform 40 is raised, and the withdrawal conveyors 50 and 52 and the chuck 42 are retracted during this time, and the tray group is combined into one. Next, the elevator base 40 is lowered, and the tray group 46 of FIG. Among the trays cut out from the stacking device 22, the conveyor 50 is lifted and supported on the bottom surface of the flange of the lowermost tray, and the tray group 48 of FIG. In this way, an arbitrary number of trays can be arranged at an arbitrary position. However, in the case of the separation device 22, the trays are separated one by one.

  The stacking device 22 can also stack a tray or a group of trays loaded from the conveyor 19 at an arbitrary height position. For example, when stacking a new tray between the tray group 46 and the tray group 48 in FIG. 2, the tray group 46 is raised by the elevator 40, and the chuck 42 is advanced and supported when the tray group 46 is raised to a predetermined position. Next, the tray group 48 is lowered together with the lift 40 and the exit / exit conveyor 52 is raised to receive the tray 44 or the tray group from the conveyor 19. As described above, the spreading device 22 can also be used as the spreading device 12 and the stacking devices 14 and 24. If the ID reader (not shown) is provided in the spreading device 22 to read the ID provided on the back surface of the workpiece, the workpiece can be conveyed more accurately.

  FIG. 3 shows the control of the conveyance mode. When pilot production is performed by starting up a liquid crystal panel factory, starting up production of new varieties, or when the process is unstable due to reorganization of processing equipment, the transport amount is generally small. Therefore, here, the single-wafer conveyance is performed, and although not particularly necessary, the conveyance speed of the conveyor or the like is increased. When the processing amount increases, the transport mode is switched to the stacked transport, and the transport speed is reduced accordingly. At this point, the process is still unstable, and stacking is performed in order to have as many buffers as possible for each processing apparatus. Next, when the process is stabilized, the buffer amount for each processing apparatus is reduced, and the process is switched to single-wafer conveyance so that the tray can be conveyed to a necessary processing apparatus at a necessary time. Along with this, the conveying speed is increased. After this, if there is a process change due to re-arrangement of processing equipment or the launch of a new product, the process returns to the launch process.

In the embodiment, the following effects can be obtained.
(1) By changing the tray transport mode in the in-process transport from the stack transport to the single wafer transport, when the process is started up, the production volume has increased, but the process is still unstable In the stable period of the process, it is possible to switch to the optimum form for the processing apparatus side.
(2) Single-wafer transportation is performed by driving the conveyor at high speed during the stable period of the process, so that the stock in the transportation process can be minimized and the tray can be transported to the necessary processing equipment at the required time.
(3) By disposing a stacking device on the inlet side to each processing device and a stacking device on the outlet side, it is possible to cope with both stacking conveyance and single wafer conveyance. The stacking device and stacking device operate as a buffer for each processing device.
(4) By using a two-level conveyor, even in the case of a processing device that has only a load port for one workpiece, the workpiece is unloaded from the load port and placed on the empty tray that has passed through the second-level conveyor. The work taken out by the take-out device can be carried into the load port.
(5) By reducing the stacking and conveying speed, workpiece vibration can be suppressed, the load on the conveyor can be reduced, and an appropriate working time can be given to the stacking device and stacking device on the processing device side.

The top view which shows the layout of the conveyance system of an Example Side view of the stacking / stacking device used in the examples The flowchart which shows the switching algorithm of the single wafer conveyance in an Example, and lamination | stacking conveyance

Explanation of symbols

2 Conveying system 4 Processing device 6 Stacker crane 8 Traveling rail 10 Rack 12, 22 Stacking device 14, 24 Stacking device 16 In-process transport conveyor 18 Conversion conveyor 19 Conveyor 26 Work picking device 28 Load port 30 Mounting device 32 Two steps Conveyor 34 In-process transport controller 36 Logistics controller 40 Lift platform 42 Chuck 44 Tray 46, 48 Tray group 50, 52 Exit / conveyor

Claims (4)

A stacking device that stacks trays on which workpieces are placed, a stacking device that stacks the trays, a conveyor that transports trays between the stacking device and the stacking device and supplies workpieces to a processing device,
A transport system comprising: a control means for changing a transport mode by changing the number of stacked trays to be supplied to the conveyor from the leveling device. The control means is characterized in that the transport mode is changed between single-wafer transport for transporting trays one by one and stacked transport for stacking and transporting a plurality of trays. The transport system according to claim 1. The transport system according to claim 1, wherein the control unit changes a transport mode according to an operation state of the processing apparatus. In addition to providing another stacking / unstacking device at the connecting portion between the processing apparatus and the conveyor, the conveyor speed is changed so that it is low when the number of stacked sheets is large and high when the number of stacked sheets is small. The conveyance system according to claim 1, wherein the conveyance system is configured as described above.

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