JP2016113250A - Buffer system and article buffer method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a buffer system that can store a large number of articles and can operate even in a last-in first-out method.CONSTITUTION: The buffer system comprises a storage portion that can store a plurality of articles in series along a direction orthogonal to a travelling direction of a conveying vehicle and freely deliver the articles between the conveying vehicle and the portion at only a head position of the series, and a moving mechanism that moves the articles along an orthogonal direction in the storage portion. The buffer system further comprises a memory for storing attributes in production management of articles allocated to the storage portion, and comprises a controller that performs control so that only articles matching the attributes are stored in the storage portion.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a buffer system and an article storage method, and more particularly to increasing the capacity of the buffer.

  Patent Document 1 (JP3622101B) and Patent Document 2 (JP4636379B) disclose buffers that temporarily store articles with an overhead traveling vehicle. These buffers are composed of conveyors on which a plurality of articles can be placed, and the conveyors can move the articles in a direction perpendicular to the rails of the overhead traveling vehicle so that a desired position can be positioned directly below the rails of the overhead traveling vehicle. Therefore, these buffers can be called random access buffers, and space is required on both the left and right sides of the rail of the overhead traveling vehicle. However, in the case of a tall processing device, it is not possible to place buffers across the rails of an overhead traveling vehicle.

JP3622101B JP4636379B

  When only a space on one side of the rail of the overhead traveling vehicle is used, when a plurality of articles are placed in series in a direction perpendicular to the rail, the articles are stored in last-in first-out (LIFO). In an overhead traveling vehicle system or the like, it is important that an article with a specified ID arrives at a destination, so it is difficult to operate a buffer with last-in first-out.

  It is an object of the present invention to provide a buffer system and a method for buffering articles that can be stored in a large number of articles and can be operated even in last-in first-out order.

The present invention is a buffer system for delivering articles to and from a transport vehicle,
A storage unit capable of storing a plurality of articles in series along a direction perpendicular to the traveling direction of the transport vehicle, and capable of delivering the articles to and from the transport vehicle only at the head position of the row;
A moving mechanism for moving an article along the direction in which the storage unit is orthogonal;
A controller that includes a memory for storing an attribute in production management of an article assigned to the storage unit, and that controls only an article that matches the attribute to be stored in the storage unit;
It is characterized by having.

The present invention also relates to a method of buffering an article for delivering and temporarily storing the article with a transport vehicle,
A storage unit capable of storing a plurality of articles in series along a direction perpendicular to the traveling direction of the transport vehicle, and capable of delivering the article to and from the transport vehicle only at the top position of a row;
A moving mechanism for moving an article along the direction in which the storage unit is orthogonal;
A buffer system having a controller with a memory,
Storing the production management attributes of the articles assigned to the storage unit in the memory;
When receiving an article from the transport vehicle, the controller obtains the production management attribute of the article and controls the controller so that only the article that matches the production management attribute assigned to the storage unit is stored in the storage unit. Step,
And do.

  The storage unit of the present invention buffers the articles by last-in first-out (LIFO) because the transport vehicle can deliver the articles only to the head of the line. For this reason, there is a problem as a buffer when transporting a designated article to a designated position. However, if an attribute for production management is defined for an article so that articles with the same attribute can be handled equally, and only the article with the same attribute is stored in the same storage unit, for last-in first-out, There is no problem even if the order of conveying the articles in the buffer is changed. For this reason, in the present invention, the buffer capacity of the article can be increased, and no problem occurs even if the article is stored by last-in first-out. Note that it is preferable to provide a plurality of storage units, for example, so that different attributes may be assigned to each storage unit. In the embodiment, when the storage unit is called a lane and the storage unit is configured by a conveyor, the conveyor becomes a moving mechanism.

  For example, when the article is a carrier of a semiconductor wafer, the attribute is set so as to indicate the classification of the carrier, and the carrier having the same attribute is set to an equivalent carrier in the subsequent process. Then, the carrier with the specified ID is not carried out from the buffer, but the carrier whose attribute is specified is carried out from the buffer. There is no problem if the carriers having the same attributes are equivalent carriers in the processing apparatus at the transport destination. For this reason, the carrier can be stored by last-in first-out.

  Preferably, the controller is configured such that when the storage unit becomes empty, the production management attribute of the article assigned to the storage unit can be changed. In this way, the storage unit can be operated more efficiently.

  Preferably, the transport vehicle is an overhead traveling vehicle that travels along a looped rail, and the storage unit is arranged in a space inside the loop from directly below the rail. If it does in this way, the buffer of goods can be utilized for the empty space inside a loop.

Example buffer system and surrounding plan view Plan view of the buffer system of the embodiment Second embodiment buffer system and surrounding plan view Side view of main part of surrounding and buffer system of second embodiment Plan view of the buffer system of the second embodiment Block diagram of control system in each embodiment The flowchart which shows the acceptance algorithm of the article | item in each Example

  In the following, an optimum embodiment for carrying out the present invention will be shown. The scope of the present invention should be determined according to the understanding of those skilled in the art based on the description of the scope of the claims, taking into account the description of the specification and well-known techniques in this field.

  FIGS. 1 and 2 show a first embodiment, FIGS. 3 to 5 show a second embodiment, FIG. 6 shows a control system in each embodiment, and FIG. 7 shows an article acceptance algorithm. In the drawings, the same reference numerals represent the same items. Reference numeral 2 denotes a buffer system of the first embodiment, which is provided in a clean room such as a semiconductor factory, a liquid crystal factory, or a chemical factory, and is used for temporary storage of articles such as FOUP and SMIF. These articles are semiconductor wafers, reticles, It is a carrier that stores medicines, their intermediates, liquid crystal panels, etc.

  12 is an overhead traveling vehicle rail (hereinafter referred to as rail 12), 14 is an overhead traveling vehicle, 16 is a processing device such as a semiconductor, and is provided with a load port 18 for delivering articles to and from the overhead traveling vehicle 14 etc. . The overhead traveling vehicle 14 travels in one direction along the looped rail 12, moves up and down an elevator (not shown), transfers articles, and further includes a lateral movement device. Articles can be transferred between The overhead traveling vehicle 14 may not be provided with a lateral movement device, and another transport vehicle may be used instead of the overhead traveling vehicle 14, and the other transport vehicle may not include a transfer device. .

  The buffer system 2 includes, for example, four lanes 4a to 4d in the space inside the loop from directly below the rail 12. The buffer system 2 further includes a controller 10, and each of the lanes 4a to 4d includes a front row placement unit 6 and a rear row placement unit 8. The controller 10 stores the production management attributes assigned to each lane, the presence / absence of articles in the placement units 6 and 8, the ID of the articles, and the like. In each of the lanes 4a to 4d, the production management attributes of the articles that may be stored are assigned dynamically, in other words, changeable by the controller 10, and only the articles that match the production management attributes are assigned to each lane 4a to 4d. Stored in lanes 4a-4d. Each of the lanes 4a to 4d includes two stages, that is, a front stage mounting part 6 and a rear stage mounting part 8, but the number of stages is arbitrary as long as it is plural and the number of lanes is arbitrary. In addition, a portion having only one stage mounting portion may exist separately from the lanes 4a to 4d. FIG. 1 shows two buffer systems 2 and 2, one for an overhead traveling vehicle equipped with a lateral movement device and the other for an overhead traveling vehicle not equipped with a lateral movement device.

  “Production management attributes” will be described. Goods such as FOUPs used in semiconductor factories can be distinguished by their usage history, types of wafers to be stored, and the following uses. For example, in a process sensitive to metal impurities adhering to a wafer, it is necessary not to use FOUP that passes through a processing apparatus that handles metal, and to use only FOUP that does not pass through a processing apparatus that handles metal. Also, when sorting wafers with a sorter and packing wafers into empty FOUPs for each subsequent process, it is necessary to distinguish empty FOUPs into multiple types depending on the type of wafer, the type of the next process, and the like. If the concept of local clean develops and the degree of cleanliness in the semiconductor factory is not uniform, it is necessary to distinguish between FOUPs that are used only in clean areas and those that are not. An attribute representing such distinction is an attribute in the production management of an article, and this attribute is assigned to the article.

  FIG. 2 shows the structure of the buffer system 2. The placement units 6 and 8 are each composed of a conveyor, and the article can be pre-packed on the placement unit 6 side or the article can be back-packed on the placement unit 8 side. You can also. In addition, goods are taken in and out by last-in first-out (LIFO). The type of conveyor is arbitrary, such as a bell conveyor or roller conveyor, and the storage capacity of articles per lane is also arbitrary.

  3 to 5 show the buffer system 20 of the second embodiment, and are the same as those of the first embodiment, except as otherwise noted. As shown in FIG. 4, the buffer system 20 includes a local rail 26 directly below the overhead traveling vehicle rail 12, runs a local carriage 28, and lanes 22a to 22d are provided below them. Reference numeral 24 denotes an article such as FOUP, and the local carriage 28 includes a traveling unit and a hoist so that the article 24 can be transferred along the vertical direction. The lanes 22a and 22d are composed of fixed two-stage placement units 30 and 32, as in the first embodiment of FIGS. 1 and 2, but in the lanes 22b and 22c, the previous stage placement unit 30 is It is possible to advance and retreat between the advance position immediately below the rails 12 and 26 and the side retreat position.

  FIG. 5 shows lanes 22a to 22d in the buffer system 20, and the local rail 26 and the overhead traveling vehicle rail 12 are shown by chain lines. Reference numeral 30 denotes a front stage mounting part, and 32 denotes a rear stage mounting part. A carriage 34 having a lift 38 moves back and forth between a front stage and a rear stage along a guide 36 or a rail, and the articles are transferred to and from the placement units 30 and 32 by raising and lowering the lift 38. The carriage 34 is a conveyor that moves articles between the placement units 30 and 32, and is an example of a moving mechanism. In lanes 22b and 22c, the preceding stage mounting portion 30 is positioned between the transfer position immediately below the rails 12 and 26 and the retreat position on the side of the rails 12 and 26 by the advance / retreat device including the cylinder 40 and the piston 41. And you can move forward and backward. The type of the advancing / retreating device is arbitrary, and a device equipped with a ball screw or a belt and a gear may be used. Here, fixed lanes 22a and 22d and slidable lanes 22b and 22c are mixed, but all slidable lanes may be used, and the number of lanes, the number of mounting portions per lane, etc. are arbitrary. is there. The local rail 26 and the local carriage 28 transfer the articles between the load ports and arrange the articles in the buffer 20 instead of the overhead traveling vehicle 14. However, the local rail 26 and the local carriage 28 may not be provided.

  Also in the second embodiment, the buffer system 20 temporarily stores articles by last-in first-out. Each of the lanes 22a to 22d is assigned an attribute for production management of articles that may be stored, and this attribute can be changed by the controller 10. In the second embodiment, since the local cart 28 transfers articles and the like between the load port and the lanes 22a to 22d, the burden on the overhead traveling vehicle 14 is reduced. In lanes 22b and 22c, the placement unit 30 can advance and retreat. Therefore, the lanes 22b and 22c are advanced immediately above the load port, the local carriage 28 is loaded from the placement unit 30, and the placement unit 30 is moved backward. Then, when the local cart 28 unloads the article to the load port, it can be unloaded in a short time. Similarly, it can be loaded from the load port in a short time.

  FIG. 6 shows the configuration of the controller 10. The processor 42 performs arithmetic and logical processing, etc., and the memory 44 is stored in the buffer systems 2 and 20, the ID of the stored article for each mounting position, and the production management assigned to each lane. The attributes, etc. are stored. The memory 44 may be a memory physically independent from the processor 42 or a memory such as a cache in the processor 44. The communication unit 46 communicates with a host controller such as the material management system 58 and inquires about the ID of the article, the attribute in production management, and the like. For example, the material management system 58 makes an inquiry to the production management system 56 to acquire the attribute of production management of the article and notifies the communication unit 46 of the attribute. However, there are cases where the material management system 58 can uniquely recognize the production management attributes of the article, and the ID of the article can be rewritten so that the production management attributes are included in the ID. Thus, the production management attribute may be read from the article ID. The interlock unit 48 communicates with the overhead traveling vehicle 14 and performs an interlock related to the transfer of the article. The conveyor drive 50 controls the conveyor or carriage of each lane to move the article between the front stage and the rear stage. The local cart drive 52 controls the local cart, and the slide buffer drive 54 controls the cylinder 40 and the like to advance and retract the placement unit 30 in the lanes 22b and 22c. The interlock unit 48, the local cart drive 52, and the slide buffer drive 54 shown by chain lines may not be provided.

  FIG. 7 shows an article acceptance algorithm. When an article is received from the overhead traveling vehicle 14 or the like, the controller 10 of the buffer system 2 or 20 reads the ID of the article by an ID reader (not shown) or is notified of the ID of the article from the material management system 56 or the like. For example, by inquiring the material management system about the production management attribute, the controller 10 acquires the production management attribute of the article such as FOUP (step 1). If there is a lane to which the same attribute is assigned and there is a vacancy (Step 2), the article is received in that lane (Step 3). If necessary, the conveyor is operated to empty the previous stage, Accept the article (step 4). Also, there is no lane having the same attribute and a vacancy, but when another lane can be assigned to the attribute (step 2), the article is similarly received (step 5). If there is no lane that can be allocated to the article (step 2), it is not accepted (step 7), and is notified to the host controller such as the material management system 56 (step 8). The host controller changes the transport destination for an unacceptable article.

  For example, in a diffusion furnace in a semiconductor factory, wafers in a plurality of FOUPs are processed as one batch, and any FOUP may arrive first as long as it is the same batch of FOUPs. Therefore, the ID of the batch of the processing in the diffusion furnace or the like is assigned to the lanes of the buffer systems 2 and 20 as the production management attribute, and the same production management attribute FOUP is temporarily stored in the same lane. In this case, there is no problem even if the arrival order and the delivery order of the FOUPs to the buffer systems 2 and 20 are different for last-in first-out. The buffer systems 2 and 20 are preferably provided along the overhead traveling vehicle rail 12 at a position facing the diffusion furnace or upstream of the diffusion furnace.

  A processed wafer may be refilled by a sorter. In this case, it is preferable to select an empty FOUP according to the contents of future processing on the wafer or the rank of cleanliness necessary for the wafer. Therefore, the production management attributes of the empty FOUP are determined according to the usage history of the FOUP, for example, the number of times of use since the previous cleaning, the elapsed period, the type of the processing apparatus that carried or carried the wafer, and the like. Then, the buffer systems 2 and 20 facing the sorter along the overhead traveling vehicle rail 12 or upstream of the sorter allocate lanes according to the production management attributes and store empty FOUPs. Also in this case, since the FOUP production management attribute is important, not the FOUP ID itself, there is no problem even if the FOUP is stored by last-in first-out.

  In addition to these cases, if the FOUP production management attribute is important rather than the FOUP ID itself, the same production management attribute FOUP is stored in the same lane, and it is stored in a first-in first-out manner within one lane. There is no problem even if FOUP is temporarily stored. By storing multiple items (FOUP) in one lane, the buffer capacity is increased. The lane production management attribute may be fixed, but if the controller 10 is dynamically assigned, a limited number of lanes can be efficiently operated. In the embodiment, the buffer systems 2 and 20 are managed by the controller 10, but a controller higher than the buffer systems 2 and 20 or the like, or one controller 10 may manage a plurality of buffer systems. .

  The embodiment further has the following characteristics. The overhead traveling vehicle rail 12 has a loop shape, and the lanes 4a to 4d and 22a to 22d are provided from directly below the rail 12 to the inside of the loop. For this reason, the ceiling space inside the loop can be used effectively.

2,20 buffer system
4a to 4d lane (storage section)
6,8 Place
10 Controller
12 Overhead rail
14 Overhead car
16 Processing unit
18 Loadport
22a-22d lane (storage)
24 goods
26 Local rail
28 Local cart
30,32 Place
34 bogie
36 Guide
38 Lift platform
40 cylinders
41 piston
42 processor
44 memory
46 Communication unit
48 Interlock unit
50 Conveyor drive
52 Local trolley drive
54 Slide buffer drive
56 Material Management System (MCS)
58 Production Management System (MES)

Claims (5)

A buffer system for delivering goods to and from a transport vehicle,
A storage unit capable of storing a plurality of articles in series along a direction perpendicular to the traveling direction of the transport vehicle, and capable of delivering the articles to and from the transport vehicle only at the head position of the row;
A moving mechanism for moving an article along the direction in which the storage unit is orthogonal;
A controller that includes a memory for storing an attribute in production management of an article assigned to the storage unit, and that controls only an article that matches the attribute to be stored in the storage unit;
And a buffer system.   2. The buffer system according to claim 1, wherein the controller is configured such that when the storage unit becomes empty, the production management attribute of an article assigned to the storage unit can be changed. The transport vehicle is an overhead traveling vehicle that travels along a looped rail,
3. The buffer system according to claim 1, wherein the storage unit is arranged in a space inside the loop from directly below the rail. The article is a semiconductor wafer carrier,
4. The buffer system according to claim 3, wherein the attribute represents a carrier classification, and the attribute is defined so that a carrier having the same attribute becomes an equivalent carrier in a subsequent process. A method for delivering and temporarily storing goods with a transport vehicle,
A storage unit capable of storing a plurality of articles in series along a direction perpendicular to the traveling direction of the transport vehicle, and capable of delivering the article to and from the transport vehicle only at the top position of a row;
A moving mechanism for moving an article along the direction in which the storage unit is orthogonal;
A buffer system having a controller with a memory,
Storing the production management attributes of the articles assigned to the storage unit in the memory;
When receiving an article from the transport vehicle, the controller obtains the production management attribute of the article and controls the controller so that only the article that matches the production management attribute assigned to the storage unit is stored in the storage unit. Step,
A method for buffering articles.

Images