Variable pitch storage shelves
The present invention generally comprises a container storage system for efficiently storing large capacity and small capacity containers or FOUPs. In one embodiment, each storage location within the stocker comprises a pair of spaced apart supports. A large capacity container or a small capacity container may be seated in any storage location. The storage locations are arranged within the stocker to minimize the amount of empty space between the supports of a storage location and a container seated in an adjacent storage location. In one embodiment, the vertical pitch between supports of adjacent storage locations is less than the height of a large capacity FOUP container shell. Thus, when a FOUP is seated in a storage location, its container shell extends between the supports of the storage location located directly above.
The present invention generally comprises a container storage device for simultaneously storing multiple containers of different dimensions in an efficient manner. More specifically, the present invention comprises a stocker for efficiently storing a plurality of Front Opening Unified Pods (FOUPs), or other containers with a mechanically openable door, that have varying dimensions.
BACKGROUND OF THE INVENTIONThe stocker 10 shown in
Each shelf 12 may extend under any portion of the FOUP 2 as long as the shelf 12 adequately supports the FOUP 2. For example, each shelf 12 may comprise an area substantially equal to the bottom surface of the FOUP 2. Or the shelf 12 may comprise an area less than the area of the FOUP's bottom surface, as long as the shelf 12 may adequately support the FOUP 2 (e.g., the FOUP 2 will not tip over, wobble, etc. on the shelf 12). Each shelf 12 may also comprise a 3-point support fork or any other support structure known within the art.
Thus, an improved stocker for simultaneously storing both small-capacity FOUPs 20 and large-capacity FOUPs 2 is needed in the industry. The present invention provides such a stocker.
SUMMARY OF THE INVENTIONOne aspect of the present invention is to provide a container storage system that may simultaneously store both large-capacity containers and small-capacity containers in an efficient manner. In one embodiment, a small-capacity container comprises a FOUP for storing less than twenty-five semiconductor wafers and a large-capacity container comprises a conventional FOUP for storing up to twenty-five semiconductor wafers or more. The container storage system may store a small capacity or large capacity FOUP in any of the storage locations.
Another aspect of the present invention is to provide a container storage system having storage locations with standardized supports. In one embodiment, each storage location comprises a pair of supports. Each pair of supports are preferably separated by a distance greater that the width of the large-capacity FOUP shell. Even though the vertical pitch between the supports of adjacent storage locations is less than the height of a large capacity FOUP shell, a large-capacity FOUP may be stored in any storage location. The large capacity FOUP shell, when the large capacity FOUP is seated on a pair of supports, extends between the pair of supports located directly above. The pair of supports do not have to adjust to accommodate the large capacity FOUP.
Yet another aspect of the present invention is to provide a container storage system with storage locations that align and/or include registration features to ensure that each container is properly seated within the storage location. In one embodiment, each support within the storage location includes at least one registration feature, such as a kinematic pin or other location element, that registers with a bottom plate or flange of the FOUP. In another embodiment, each support includes a side wall to prevent the large capacity FOUP from moving laterally while seated on the supports.
Still another aspect of the present invention is to provide a container storage system that provides safety features to ensure that containers do not contact each other during transport and handling within the storage system. In one embodiment, at least one support in each storage location includes a sensor to detect whether a FOUP is seated within the storage location. The sensor prevents a transport mechanism from attempting to deliver a container to an already occupied storage location.
Semiconductor Equipment and Materials International (SEMI) has created standards for semiconductor wafer manufacturing equipment (see http://www.semi.org). The SEMI Standards govern acceptable tolerances and interfaces for semiconductor manufacturing equipment. The inventions described herein are not limited to semiconductor manufacturing equipment for handling FOUPs or other types of containers.
By way of example only, the various embodiments of the present invention may also be used and/or adapted for systems handling SMIF pods, reticle containers, flat panel display transport devices, or any other container or processing tool. Container is defined as any type of structure for supporting an article including, but not limited to, a semiconductor substrate. By way of example only, a container includes a structure that comprises an open volume whereby the article can be accessed (e.g., FPD transport) or a container having a mechanically openable door (e.g., bottom opening SMIF pod and FOUP). For purposes of describing this invention, however, only FOUPs will be referenced herein.
The stocker 100 is described throughout in operation with a small capacity FOUP 20 and a large capacity FOUP 2 each having a bottom plate 32 and 12, respectively (see
While a container is seated in a storage location, the flange(s) is seated on the supports 101 (e.g., the bottom plate 12 of the FOUP 2 is seated on the supports 101). If, for example, a container includes a flange extending from the top of the container, the container is hung or suspended from the supports 101 by the flange seated on the supports 101. By way of example only, a flange may comprise a horizontal, angled or stepped surface, a series of pins or rods extending from the container shell, and so on. Similarly, the supports 101 may comprise any structure for supporting the container's flange features. If, for example, a conventional FOUP is seated in a storage location, the supports 101 and the FOUP flange preferably mate such that the workpieces stored in the FOUP are substantially horizontal while the FOUP is seated in the storage location. Of course, the workpieces stored in a container may be oriented in any position in the container while the container is seated in a storage location (e.g., vertical, angled, etc.). For purposes of describing this invention only, the stocker 100 will be described in operation with containers including a bottom plate and corresponding supports for supporting the container substantially horizontal.
In the case where the bottom support plate of a large capacity FOUP and a small capacity FOUP are the same width, the distance or pitch d4 between supports 101 may be standardized for the entire stocker 100. For example, support structures 102 and 104, which are supporting a large capacity FOUP 2 in
The stocker 100 shown in
The stocker 100 shown in
The stocker 100, as shown in
The support structure 101 may comprise many different structures. In one embodiment, each support structure 101 consists of a support bar, and each pair of supports 101 are set apart at a horizontal pitch or distance d4. The pitch d4 between support structures 101 comprises a distance that provides maximum storage of the small capacity FOUPs 20 without wasted space within the stocker 100. The pitch d4 is also determined, in part, by the width of the bottom plate or flange on each FOUP. By standardizing the width of the bottom plate or flange on each FOUP, the pitch d4 may also be standardized.
Each support structure 101 is also separated or set apart vertically by a distance d5 from another support 101.
The large capacity FOUP 2 has similar features as the small capacity FOUP 20. The large capacity FOUP 2 includes a container shell 4, a mechanically openable door 9 that couples with the front opening 3, a top handle 6, a pair of side handles 8 and a bottom plate or flange 12. The container shell 4 and the bottom flange 32 each have a tapered configuration. The front opening 3, in this embodiment, is substantially the same width W1 as the bottom flange 32. And the width W2 of the front opening 3 is greater than the width W2 of the container shell 4.
Each support structure 101 may include pins (e.g., kinematic pins) or other registration or location features that would accurately engage mating features on both the large capacity FOUP's bottom plate 12 and the small capacity FOUP's bottom plate 32. These registration features would allow a FOUP to be placed on a pair of support structure 101 or in a storage location in an accurate and repeatable location. In one embodiment, the storage location may include two rounded pins on one support structure 101 (e.g., support 102) and one rounded pin on the other support structure 101 (e.g., support 104). The pair of support structures 102 and 104 would then include three corresponding registration features similar to the arrangement used for the kinematic pin alignment on 300 mm FOUPs, which are standardized by SEMI. Other alignment and/or registration features are also possible on each support structure 101. These registration features would also engage a flange extending from the FOUP if the FOUP was, for example, seated in a storage location by its flange.
One or more support structures 101 in each storage location may include a sensor to determine if, for example, a FOUP is seated in the storage location. This feature may be useful to prevent any type of placement or collision errors even though the robot or transfer device that moves FOUPs between storage locations may be recording which storage locations are currently occupied. A sensor on each support structure 101 could provide a cross check or confirm that the transfer device is accurately recording this information. The transfer device may also include sensors that sense the bottom placement of the container and the containers height to cross check the stored placement information and assure that the container is gripped at the correct level or that a position (or positions) is unoccupied.
It should be appreciated that the above-described stocker 100 and methods for storing and transporting FOUPs within the stocker 100 are for explanatory purposes only and that the invention is not limited thereby. Having thus described a preferred embodiment of a method and system for storing FOUPs, it should be apparent to those skilled in the art that certain advantages of the within system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. For example, the stocker 100 may also be used in connection with other equipment within in a semiconductor fabrication facility, and it should be apparent that many of the inventive concepts described above would be equally applicable to the use of other non-semiconductor manufacturing applications.
Claims
1. A container storage device for storing large capacity workpiece containers and small capacity workpiece containers, each small capacity workpiece container and large capacity workpiece container includes a container shell and a flange, the container storage device comprising:
- a first storage location for supporting a workpiece container by its flange, said first storage location having a first support spaced apart from a second support by a predetermined distance that is greater than the width of a container shell of a large capacity workpiece container; and
- a second storage location for supporting the flange of a workpiece container, located above said first storage location, including a first support spaced apart from a second support by a predetermined distance that is greater than the width of a container shell of a large capacity workpiece container;
- wherein the vertical pitch between said first and second supports of said first storage location and said first and second supports of said second storage location is less than the height of the container shell of a large capacity workpiece container.
2. The container storage device as recited in claim 1, wherein said first support and said second support of said first storage location each include a registration feature for engaging the flange of either a large capacity workpiece container or the flange of a small capacity workpiece container.
3. The container storage device as recited in claim 1, wherein said first support and said second support of said second storage location each include a registration feature for engaging the flange of either a large capacity workpiece container or the flange of a small capacity workpiece container.
4. The container storage device as recited in claim 1, wherein said first support and said second support of said first storage location restrict the lateral movement of a workpiece container seated on said first and second supports of said first storage location.
5. The container storage device as recited in claim 1, wherein said first support and said second support of said second storage location restrict the lateral movement of a workpiece container seated on said first and second supports of said second storage location.
6. The container storage device as recited in claim 1, wherein said first storage location includes a sensor to determine whether a workpiece container is located in said first storage location.
7. The container storage device as recited in claim 1, wherein said second storage location includes a sensor to determine whether a workpiece container is located in said second storage location.
8. A container storage device for storing large capacity workpiece containers and small capacity workpiece containers, each small capacity and large capacity workpiece container including a container shell and a flange, the container storage device comprising:
- a first storage location including a first support and a second support horizontally spaced apart from each other by a predetermined distance, said predetermined distance being greater than the width of a container shell of a large capacity workpiece container yet able to support a workpiece container by its flange;
- a second storage location, located above said first storage location, including a first support and a second support horizontally spaced apart from each other by a predetermined distance, said predetermined distance being greater than the width of a container shell of a large capacity workpiece container yet able to support a workpiece container by its flange;
- wherein when a large capacity workpiece container is located in said first storage location, the container shell of the large capacity workpiece container extends between said first support and said second support of said second storage location.
9. The container storage device as recited in claim 8, wherein said first support and said second support of said first storage location each include a registration feature for engaging the flange of either the large capacity workpiece container or the flange of the small capacity workpiece container.
10. The container storage device as recited in claim 8, wherein said first support and said second support of said second storage shelf each include a registration feature for engaging the flange of either the large capacity workpiece container or the flange of the small capacity workpiece container.
11. The container storage device as recited in claim 8, wherein said first support and said second support of said first storage location restrict the lateral movement of a workpiece container seated in said first storage location.
12. The container storage device as recited in claim 8, wherein said first support and said second support of said second storage location restrict the lateral movement of a workpiece container seated in said second storage location.
13. The container storage device as recited in claim 8, wherein said first storage location includes a sensor to determine whether a workpiece container is seated in said first storage location.
14. The container storage device as recited in claim 8, wherein said second storage location includes a sensor to determine whether a workpiece container is seated in said second storage location.
Type: Application
Filed: Nov 22, 2006
Publication Date: May 22, 2008
Inventor: Anthony C. Bonora (Portola Valley, CA)
Application Number: 11/603,714
International Classification: B65H 1/00 (20060101);