Brill, Todd J. (Round Rock, TX, US)
Teferra, Michael (Los Gatos, CA, US)
Puri, Amitabh (San Jose, CA, US)
Jessop, Daniel R. (Eagle Mountain, UT, US)
Warner, Glade L. (Sandy, UT, US)
Duffin, David C. (Sandy, UT, US)

Plaque It! Sponsored by: Flash of Genius

11/067460

08/19/2008

02/25/2005

Images are available in PDF form when logged in. To view PDFs, Login  or  Create Account (Free!)

Click for automatic bibliography generation

Applied Materials, Inc. (Santa Clara, CA, US)

198/358

198/349, 198/349.6

B65G47/46

198/349.4, 198/349.8, 198/359, 198/349.3, 414/222.01, 198/249.1-349, 414/940, 198/349.7, 198/358, 414/222.13, 198/349.2, 414/935, 364/478.01, 198/349.6, 198/349.1, 198/349.5

3845286	MANUFACTURING CONTROL SYSTEM FOR PROCESSING WORKPIECES	October, 1974	Aronstein et al.
3952388	Machine tool apparatus	April, 1976	Hasegawa et al.
4027246	Automated integrated circuit manufacturing system	May, 1977	Caccoma et al.
4049123	Methods of and apparatus for sorting articles in accordance with their resistivity and thickness	September, 1977	Fegley et al.
4166527	Device for picking up and placing articles on movable conveyors and assembly lines and to an endless construction and to an article pickup and deposit device therefor	September, 1979	Beezer
4852717	Computer controlled light contact feeder	August, 1989	Ross et al.
4936734	Chuck for transporting a wafer carrier	June, 1990	Osada	414/940
4974166	Processing systems with intelligent article tracking	November, 1990	Maney et al.	414/273
5183378	Wafer counter having device for aligning wafers	February, 1993	Asano et al.
5256204	Single semiconductor water transfer method and manufacturing system	October, 1993	Wu
5372471	Single semiconductor wafer transfer method and manufacturing system	December, 1994	Wu
5382127	Pressurized interface apparatus for transferring a semiconductor wafer between a pressurized sealable transportable container and a processing equipment	January, 1995	Garric et al.
5388945	Fully automated and computerized conveyor based manufacturing line architectures adapted to pressurized sealable transportable containers	February, 1995	Garric et al.
5390785	Pressurized sealable transportable containers for storing a semiconductor wafer in a protective gaseous environment	February, 1995	Garric et al.
5411358	Dispatching apparatus with a gas supply distribution system for handling and storing pressurized sealable transportable containers	May, 1995	Garric et al.
5544350	Ratio of running work in progress	August, 1996	Hung et al.
5562383	Treatment apparatus	October, 1996	Iwai et al.
5570990	Human guided mobile loader stocker	November, 1996	Bonora et al.	414/940
5612886	Method and system for dynamic dispatching in semiconductor manufacturing plants	March, 1997	Weng
5668056	Single semiconductor wafer transfer method and manufacturing system	September, 1997	Wu et al.
5696689	Dispatch and conveyer control system for a production control system of a semiconductor substrate	December, 1997	Okumura et al.
5751581	Material movement server	May, 1998	Tau et al.	700/115
5811211	Peripheral edge exposure method	September, 1998	Tanaka et al.
5818716	Dynamic lot dispatching required turn rate factory control system and method of operation thereof	October, 1998	Chin et al.
5825650	Method for determining standard cycle time of a stage dynamically	October, 1998	Wang
5884392	Automatic assembler/disassembler apparatus adapted to pressurized sealable transportable containers	March, 1999	Lafond
5888042	Semiconductor wafer transporter	March, 1999	Oda
5957648	Factory automation apparatus and method for handling, moving and storing semiconductor wafer carriers	September, 1999	Bachrach
5971585	Best can do matching of assets with demand in microelectronics manufacturing	October, 1999	Dangat et al.
5976199	Single semiconductor wafer transfer method and manufacturing system	November, 1999	Wu et al.
5980183	Integrated intrabay buffer, delivery, and stocker system	November, 1999	Fosnight
6009890	Substrate transporting and processing system	January, 2000	Kaneko et al.
6026561	Automatic assembler/disassembler apparatus adapted to pressurized sealable transportable containers	February, 2000	Lafond
6048259	Wafer loading and unloading mechanism for loading robot	April, 2000	Asai
6050768	Automatic carrier control method in semiconductor wafer cassette transportation apparatus	April, 2000	Iwasaki et al.
6053688	Method and apparatus for loading and unloading wafers from a wafer carrier	April, 2000	Cheng
6082948	Controlled environment enclosure and mechanical interface	July, 2000	Fishkin et al.
6128588	Integrated wafer fab time standard (machine tact) database	October, 2000	Chacon
6134482	Method and apparatus for controlling semiconductor wafer fabrication equipment based on a remaining process time applicable to the processors	October, 2000	Iwasaki
6183186	Wafer handling system and method	February, 2001	Howells et al.
6196001	Environment controlled WIP cart	March, 2001	Tannous et al.
6240335	Distributed control system architecture and method for a material transport system	May, 2001	Wehrung et al.
6256550	Overall equipment effectiveness on-line categories system and method	July, 2001	Wu et al.
6351686	Semiconductor device manufacturing apparatus and control method thereof	February, 2002	Iwasaki et al.
6415260	Dynamic capacity demand forecast system	July, 2002	Yang et al.
6431814	Integrated wafer stocker and sorter with integrity verification system	August, 2002	Christensen et al.
6439822	Substrate processing apparatus and substrate processing method	August, 2002	Kimura et al.
6463350	Production system for manufacturing semiconductor devices by lot	October, 2002	Fukuda et al.
6526329	Substrate processing system and substrate processing method	February, 2003	Tateyama et al.
6540466	Compact apparatus and method for storing and loading semiconductor wafer carriers	April, 2003	Bachrach
6579052	SMIF pod storage, delivery and retrieval system	June, 2003	Bonora et al.
6587744	Run-to-run controller for use in microelectronic fabrication	July, 2003	Stoddard et al.
6641350	Dual loading port semiconductor processing equipment	November, 2003	Nakashima et al.
6662076	Management of move requests from a factory system to an automated material handling system	December, 2003	Conboy et al.
6673638	Method and apparatus for the production of process sensitive lithographic features	January, 2004	Bendik et al.
6675066	Conveyor line process control system and method	January, 2004	Moshgbar
6684124	Method for controlling a processing device for a sequential processing of semiconductor wafers	January, 2004	Schedel et al.
6715602	Sensor system for conveyor belt	April, 2004	Gartland
6745093	Vacuum process apparatus and method of operating the same	June, 2004	Kawano et al.
6788996	Fabrication method of semiconductor integrated circuit device	September, 2004	Shimizu
6839603	Semiconductor manufacturing system and control method thereof	January, 2005	Karasawa
6853876	Distributed control system architecture and method for a material transport system	February, 2005	Wehrung et al.
6873963	Shipment tracking analysis and reporting system (STARS)	March, 2005	Westbury et al.
6917844	Vacuum process apparatus and method of operating the same	July, 2005	Kawano et al.
6971500	Conveyorized storage and transportation system	December, 2005	Horn	198/348
7039495	Management of multiple types of empty carriers in automated material handling systems	May, 2006	Conboy et al.
7051870	Suspension track belt	May, 2006	Schoendienst et al.
7077264	Methods and apparatus for transporting substrate carriers	July, 2006	Rice et al.
7156221	Break-away positioning conveyor mount for accommodating conveyor belt bends	January, 2007	Rice et al.
20010038783	Dual loading port semiconductor processing equipment	November, 2001	Nakashima et al.
20010051837	Substrate processing system and substrate processing method	December, 2001	Tateyama et al.
20020071744	COMPACT APPARATUS AND METHOD FOR STORING AND LOADING SEMICONDUCTOR WAFER CARRIERS	June, 2002	Bachrach
20020081181	Substrate processing apparatus and substrate processing method	June, 2002	Yokomori et al.
20020094588	Method of control management of production line	July, 2002	Fan et al.
20020114684	Load port of a semiconductor manufacturing apparatus having integrated kinematic coupling pins and sensors, and method of loading wafers using the same	August, 2002	Jeong et al.
20020116086	Installation for processing wafers	August, 2002	Huber et al.
20020144654	Installation for processing wafers	October, 2002	Elger et al.
20020155705	Fabrication method of semiconductor integrated circuit device	October, 2002	Shimizu
20020182040	Substrate processing apparatus and substrate processing method	December, 2002	Kimura et al.
20030108407	Interbay transportation system and method of interbay transportation	June, 2003	Ogata et al.
20030113190	Compact apparatus and method for storing and loading semiconductor wafer carriers	June, 2003	Bachrach
20030202866	Method and apparatus for identifying a wafer cassette	October, 2003	Weng et al.
20040049398	Method, system, and storage medium for resolving transport errors relating to automated material handling system transactions	March, 2004	Gartland et al.
20040062633	System for transporting substrate carriers	April, 2004	Rice et al.
20040081538	Substrate carrier handler that unloads substrate carriers directly from a moving conveyor	April, 2004	Rice et al.
20040187342	Substrate treating method and apparatus	September, 2004	Izuta
20040225393	Vacuum process apparatus and method of operating the same	November, 2004	Kawano et al.
20040262132	Method and system for conveyor belt monitoring	December, 2004	Pauley et al.

DE19715974	October, 1998
EP0365589	September, 1992			METHOD AND APPARATUS FOR ALIGNING SILICON WAFERS.
EP0663686	July, 1995			Automatic assembler/disassembler apparatus adapted to pressurized sealable transportable container
EP0850720	July, 1998			Manufacturing process for an article
EP1128246	August, 2001			Push-type scheduling for semiconductor fabrication
JP55091839	July, 1980
JP58028860	February, 1983			SEMICONDUCTOR DEVICE AND MANUFACTURE THEREOF
JP60049623	March, 1985
JP63234511	September, 1988			SEMICONDUCTOR SUBSTRATE TREATMENT DEVICE
JP01181156	July, 1989
JP01257549	October, 1989			PRODUCTION LINE INFORMATION MANAGING METHOD
JP02015647	January, 1990			SEMICONDUCTOR MANUFACTURING APPARATUS
JP05128131	May, 1993			SUBCONTRACTOR CONTROL SYSTEM
JP05290053	November, 1993			PROVIDING METHOD FOR FLOWING INFORMATION IN PRODUCTION MANAGEMENT SYSTEM OF SMALL SCALE MANY KINDS
JP06132696	May, 1994			SUBSTRATE CARRIER
JP06260545	September, 1994			PRODUCTION CONTROL SYSTEM OF SEMICONDUCTOR WAFER
JP08249044	September, 1996			PRODUCTION CONTROLLER
JP09115817	May, 1997			ALIGNER AND ALIGNING METHOD
JP10135096	May, 1998			SCHEDULING METHOD IN SEMICONDUCTOR MANUFACTURE
JP11176717	July, 1999			PRODUCTION METHOD FOR SEMICONDUCTOR DEVICE, PRODUCTION MANAGEMENT METHOD/DEVICE FOR THE SEMICONDUCTOR DEVICE
JP11296208	October, 1999			PRODUCTION MANAGEMENT INFORMATION OUTPUT DEVICE
JP2000012646	January, 2000			ADAPTER DEVICE FOR CARRIER POD
JP2001332464	November, 2001			PUSH-TYPE SCHEDULING METHOD AND APPARATUS FOR MANUFACTURING SEMICONDUCTOR, PROCESS STEP PROGRAM AND MEDIUM FOR STORING THE PROGRAM
JP2003007584	January, 2003			METHOD AND SYSTEM FOR MANUFACTURING SEMICONDUCTOR DEVICE
WO/1999/028952	June, 1999			WAFER-MAPPING LOAD PORT INTERFACE
WO/2005/006408	January, 2005			FEEDING FACILITY FOR USE IN WAFER PROCESSING METHODS

Przelocki, H. et al., “DIASTEMOS-computerized system of IC manufacturing control and diagnostics”, 1990, Elektronika, vol. 31 No. 11-12, pp. 38-40, Polish Language. (Abstract only).
Lovell, A.M. et al., “Cell automation: integrating manufacturing with robotics”, Dec. 1990, Solid State Technology, vol. 33 No. 12, p. 37-9.
Prasad, K., “A generic computer simulation model to characterize photolithography manufacturing area in an IC FAB facility”, Sep. 1991, IEEE Transactions on Components, Hybrids, and Manufacturing Technology, vol. 14 No. 3, p. 483-7.
Ehteshami, B. et al., “Trade-offs in cycle time management: hot lots”, May 1992, IEEE Transactions on Semiconductor Manufacturing, vol. 5 No. 2, p. 101-6.
Lou, S. et al., “Using simulation to test the robustness of various existing production control policies”, 1991, 1991 Winter Simulation Conference Proceedings, IEEE, p. 261-9.
Berg, R. et al., “The formula: world class manufacturing for hybrid thin-film component production”, 1992, IEEE/SEMI International Semiconductor Manufacturing Science Symposium, pp. 53-60.
Naguib, H., “The implementation of total quality management in a semiconductor manufacturing operation”, 1992, IEEE/SEMI International Semiconductor Manufacturing Science Symposium, p. 63-7.
Rose, D., “Productivity enhancement”, 1992, IEEE/SEMI International Semiconductor Manufacturing Science Symposium, p. 68.
Narayanan, S. et al., “Object-oriented simulation to support operator decision making in semiconductor manufacturing”, 1992, 1992 IEEE International Conference on Systems, Man and Cybernetics, vol. 2, p. 1510-15.
Leonvich, G. A. et al., “Integrated cost and productivity learning in CMOS semiconductor manufacturing”, Jan.-Mar. 1995, IBM Journal of Research and Development, vol. 39 No. 1-2, p. 201-13.
Leonvich, G., “An approach for optimizing WIP/cycle time/output in a semiconductor fabricator”, 1994, Sixteenth IEEE/CPMT International Electronics Manufacturing Technology Symposium, ‘Low-Cost Manufacturing Technologies for Tomorrow's Global Economy’, Proceedings 1994 IEMT Symposium, vol. 1, p. 108-11.
Schomig, A.K. et al., “Performance modelling of pull manufacturing systems with batch server”, 1995, Proceedings 1995 INRIA/IEEE Symposium on Emerging Technologies and Factory Automation, ETFA '95, vol 3, p. 175-83.
Juba, R.C. et al., “Production improvements using a forward scheduler”, 1996, Seventeenth IEEE/CPMT International Electronics Manufacturing Technology Symposium ‘Manufacturing Technologies - Present and Future’, p. 205-9.
Fuller, L.F. et al., “Improving manufacturing performance at the Rochester Institute of Technology integrated circuit factory”, 1995, IEEE.SEMI 1995 Advanced Semiconductor Manufacturing Conference and Workshop, Theme - Semiconductor Manufacturing: Economic Solutions for the 21st Century, ASMC '95 Proceedings, p. 350-5.
Yan, Houmin et al., “Testing the robustness of two-boundary control polocies in semiconductor manufacturing”, May 1996, IEEE Transactions on Semiconductor Manufacturing, vol. 9 No. 2, p. 285-8.
Lopez, M.J. et al., “Performance models of systems of multiple cluster tools”, 1996 Nineteenth IEEE/CPMT International Electronics Manufacturing Technology Symposium. Proceedings 1996 IEMT Symposium, pp. 57-65.
Collins, D. W. et al., “Implementation of Minimum Inventory Variability Scheduling 1-Step Ahead Policy® in a large semiconductor manufacturing facility”, 1997, 1997 IEEE 6th International Conference on Emerging Technologies and Factory Automation Proceedings, pp. 497-504.
Labanowski, L., “Improving overall fabricator performance using the continuous improvement methodology”, 1997, 1997 IEEE/SEMI advanced Semiconductor Manufacturing Conference and Workshop. Theme - The Quest for Semiconductor Manufacturing Excellence: Leading the CHange into the 21st Century. ASMC Proceedings, pp. 405-409.
Dudde, R. et al., “Flexible data registration and automation in semiconductor production”, 1997, Proceedings of the SPIE - The International Society for Optical Engineering, pp. 171-181.
Padillo, J. M. et al., “A stratgeic domain:IE in the semiconductor industry”, Mar. 1998, IIE Solutions, pp. 36-40, 42.
Collins, D. W. et al., “Investigation of minimum inventory variability scheduling policies in a large semiconductor manufacturing facility”, 1997, Proceedings of the 1997 American Control Conference, vol. 3, pp. 1924-1928.
Rose, O., “WIP evolution of a semiconductor factory after a bottleneck workcenter breakdown”, 1998, 1998 Winter Simulation Conference. Proceedings, vol. 2, pp. 997-1003.
Iriuchijima, K. et al., “WIP allocation planning for semiconductor factories”, 1998, proceedings of the 37th IEEE Conference on Decision and Control, vol. 3, pp. 2716-2721.
Weiss, M., “New twists on 300 mm fab design and layout”, Jul. 1999, Semiconductor International, vol. 22 No. 8, pp. 103-104, 106, 108.
Van Antwerp, K. et al., “Improving work-in-progress visibility with active product tags”, Oct. 1999, Micro, vol. 17 No. 9, pp. 67-69, 72-73.
Martin, D. P., “Total operational efficiency (TOE): the determination of 2 capacity and cycle time components and their relationship to productivity improvements in a semiconductor manufacturing line”, 1999, 10th Annual IEEE/SEMI. Advanced Semiconductor Manufacturing Conference and Workshop. ASMC 99 Proceedings, pp. 37-41.
Martin, D. P., “Capacity and cycle time-throughput understanding system (CAC-TUS) an analysis tool to determine the components of capacity and cycle time in a semiconductor manufacturing line”, 1999, 10th Annual IEEE/SEMI. Advanced Semiconductor Manufacturing Conference and Workshop. SMC 99 Proceedings, pp. 127-131.
Marcoux, P. et al., “Determining capacity loss from operational and technical deployment practices in a semiconductor manufacturing line”, 1999, 1999 IEEE International Symposium on Semiconductor Manufacturing Conference Proceedings, pp. 3-5.
Chen, J. C. et al., “Capacity planning for the twin fab”, 1999, 1999 IEEE International Symposium on Semiconductor Manufacturing Conference Proceedings, pp. 317-320.
Wei Jun-Hu et al., “Optimization methodology in simulation-based scheduling for semiconductor manufacturing”, Oct. 2000, Information and Control, vol. 29 No. 5, pp. 425-430, Chinses Language. (Abstract only).
Hughlett, E., “Incremental levels of automation in the compound semiconductor fab”, Aug. 2001, Compound Semiconductor, vol. 7 No. 7, pp. 69-73.
Sarin, S. C. et al., “Reduction of average cycle time at a wafer fabrication facility”, 2001, 2001 GaAs MANTECH Conference. Digest of Papers, pp. 241-246.
Saito, K. et al., “A simulation study on periodical priority dispatching of WIP for product-mix fabrication”, 2002, 13th Annual IEEE/SEMI Advanced Semiconductor Manufacturing Conference. Advanceing the Science and Technology of Semiconductor manufacturing. ASMC 2002, pp. 33-37.
Wang, J. et al., “The improvement of automated material handling system traffic control”, 2002, 2002 Semiconductor Manufacturing Technology Workshop, pp. 271-274.
Lee, Wei Jie, “Optimize WIP scale through simulation approach with WIP, turn-over rate and cycle time regression analysis in semiconductor fabrication”, 2002, 2002 Semiconductor Manufacturing Technology Workshop, pp. 299-301.
Lee, Young Hoon et al., “Push-pull production planning of the re-entrant process”, 2003, International Journal of Advanced Manufacturing Technology, vol. 22 No. 11-12, pp. 922-931.
Garlid, Scott C., “From philosophy to reality: interpreting the rules of JIT for IC manufacturing”, 1989, SME Technical Paper (Series) MS. Publ by SME, pp. MS89-797-1-15.
Anon, “Wafger level automation”, Jan. 1995, European Semiconductor, vol. 17 No. 1, pp. 17 and 19.
Anon, “The coming of fab-wide automation”, May 1998, European Semiconductor Design Production Assembly, vol. 20 No. 5, pp. 21-22.
Pierce, Neal G. et al., “Dynamic dispatch and graphical monitoring system”, 1999, IEEE International Symposium on Semiconductor Manufacturing Conference, Proceedings 1999, pp. 65-68.
Nagesh, Sukhi et al., “Intelligent seond-generation MES solutions for 300mm fabs”, 2000, Solid State Technology, vol. 43 No. 6, pp. 133-134,136, 138.
“300mm single-wafer transport”, Jul. 1999, Solid State Technology - semiconductor manufacturing and wafer fabrication, Semicon West '99 Product Spotlight, pp. 5-6.
“300mm single-wafer handling”, Apr. 2000, Solid State Technology, Product News, , pg. 99.
Griessing, Jurgen et al., “Assessing the feasibility of a 33-mm test and monitor wafer handeling and logistics system”, Jul. 2000, Micro: The 300-mm Imperative, pp. 1-19.
“The Leading Company in Micro environment”, Jan. 3, 2002, Incam Solutions Company, pp. 1-2.
“Improved wafer isolation and additional flexibility”, Jan. 3, 2002, Incam Solutions Company SWIF technology, pp. 1-2.
“SEMI standard compliance” and “Related SEMI standards”, Jan. 3, 2002, Incam Solutions Related standards, pg. 1.
“Single Wafer lots Solution”, Jan. 3, 2002, Incam Solutions References, pg. 1.

Bidwell, James R.

Dugan & Dugan

The present application claims priority from U.S. Provisional Patent Application Ser. No. 60/548,574, filed Feb. 28, 2004. The content of the above-identified patent application is hereby incorporated by reference herein in its entirety.

The invention claimed is:

1. A method of electronic device manufacturing, comprising: receiving a request to transfer a carrier from a first substrate loading station to a second substrate loading station of an electronic device manufacturing facility including a plurality of substrate loading stations, wherein the facility further includes a plurality of carrier supports coupled to a conveyor system adapted to move the carrier within the facility; assigning one of the plurality of carrier supports to transfer the carrier from the first substrate loading station to the second substrate loading station such that a time required for the transfer is reduced relative to a time required for the transfer if a next available carrier support is assigned; moving the carrier from the first substrate loading station; and moving the carrier to the second substrate loading station.

2. The method of claim 1 wherein assigning one of the plurality of carrier supports to transfer the carrier from the first substrate loading station to the second substrate loading station includes: selecting one of the plurality of carrier supports; and determining whether employing the selected carrier support will conflict with a pending transfer.

3. The method of claim 2 further comprising assigning the selected carrier support for transferring the carrier from the first substrate loading station to the second substrate loading station if no conflict with a pending transfer exists.

4. The method of claim 2 further comprising, if a conflict exists with a pending transfer, selecting another one of the plurality of carrier supports.

5. The method of claim 4 further comprising: determining whether employing the other selected carrier support will conflict with a pending transfer; and assigning the other selected carrier support for transferring the carrier from the first substrate loading station to the second substrate loading station if no conflict with a pending transfer exists.

6. The method of claim 2 further comprising determining whether employing the selected carrier support will unbalance the conveyor system.

7. The method of claim 6 further comprising assigning the selected carrier support for transferring the carrier from the first substrate loading station to the second substrate loading station if no conflict with a pending transfer exists and the selected carrier support will not unbalance the conveyor system.

8. The method of claim 7 further comprising selecting another one of the plurality of carrier supports, if a conflict exists with a pending transfer or if the selected carrier support will unbalance the conveyor system.

9. The method of claim 8 further comprising: determining whether employing the other selected carrier support will conflict with a pending transfer; determining whether employing the other selected carrier support will unbalance the conveyor system; and assigning the other selected carrier support for transferring the carrier from the first substrate loading station to the second substrate loading station if no conflict with a pending transfer exists and the other selected carrier support will not unbalance the conveyor system.

10. The method of claim 2 wherein a pending transfer includes a carrier transfer between substrate loading stations.

11. The method of claim 2 wherein determining whether employing the selected carrier support will conflict with a pending transfer is based on at least one of: a first group of parameters including: a velocity of the conveyor system divided by a spacing between adjacent carrier supports coupled to the conveyor system; a maximum time required by the first substrate loading station to prepare to place a carrier on the conveyor system; and at least one of a maximum time required by the first substrate loading station to place a carrier onto the conveyor system and a maximum time required by the first substrate loading station to remove a carrier from the conveyor system; and a second group of parameters including: the velocity of the conveyor system divided by the spacing between adjacent carrier supports coupled to the conveyor system; a maximum time required by the second substrate loading station to prepare to remove a carrier from the conveyor system; and at least one of a maximum time required by the second substrate loading station to place a carrier onto the conveyor system and a maximum time required by the second substrate loading station to remove a carrier from the conveyor system.

12. An apparatus for electronic device manufacturing, comprising: a control system of an electronic device manufacturing facility adapted to: receive a request to transfer a carrier from a first substrate loading station to a second substrate loading station of the facility, wherein the facility further includes a plurality of carrier supports coupled to a conveyor system adapted to move the carrier within the facility; assign one of the plurality of carrier supports to transfer the carrier from the first substrate loading station to the second substrate loading station such that a time required for the transfer is reduced relative to a time required for the transfer if a next available carrier support is assigned; move the carrier from the first substrate loading station; and move the carrier to the second substrate loading station.

13. The apparatus of claim 12 wherein the control system is further adapted to: select one of the plurality of carrier supports; and determine whether employing the selected carrier support will conflict with a pending transfer.

14. The apparatus of claim 13 wherein the control system is further adapted to assign the selected carrier support for transferring the carrier from the first substrate loading station to the second substrate loading station if no conflict with a pending transfer exists.

15. The apparatus of claim 13 wherein the control system is further adapted to, if a conflict exists with a pending transfer, select another one of the plurality of carrier supports.

16. The apparatus of claim 15 wherein the control system is further adapted to: determine whether employing the other selected carrier support will conflict with a pending transfer; and assign the other selected carrier support for transferring the carrier from the first substrate loading station to the second substrate loading station if no conflict with a pending transfer exists.

17. The apparatus of claim 13 wherein the control system is further adapted to determine whether employing the selected carrier support will unbalance the conveyor system.

18. The apparatus of claim 17 wherein the control system is further adapted to assign the selected carrier support for transferring the carrier from the first substrate loading station to the second substrate loading station if no conflict with a pending transfer exists and the selected carrier support will not unbalance the conveyor system.

19. The apparatus of claim 18 wherein the control system is further adapted to select another one of the plurality of carrier supports, if a conflict exists with a pending transfer or if the selected carrier support will unbalance the conveyor system.

20. The apparatus of claim 19 wherein the control system is further adapted to: determine whether employing the other selected carrier support will conflict with a pending transfer; determine whether employing the other selected carrier support will unbalance the conveyor system; and assign the other selected carrier support for transferring the carrier from the first substrate loading station to the second substrate loading station if no conflict with a pending transfer exists and the other selected carrier support will not unbalance the conveyor system.

21. The apparatus of claim 13 wherein a pending transfer includes a carrier transfer between substrate loading stations.

22. The apparatus of claim 13 wherein the control system is further adapted to determine whether employing the selected carrier support will conflict with a pending transfer based on at least one of: a first group of parameters including: a velocity of the conveyor system divided by a spacing between adjacent carrier supports coupled to the conveyor system; a maximum time required by the first substrate loading station to prepare to place a carrier on the conveyor system; and at least one of a maximum time required by the first substrate loading station to place a carrier onto the conveyor system and a maximum time required by the first substrate loading station to remove a carrier from the conveyor system; and a second group of parameters including: the velocity of the conveyor system divided by the spacing between adjacent carrier supports coupled to the conveyor system; a maximum time required by the second substrate loading station to prepare to remove a carrier from the conveyor system; and at least one of a maximum time required by the second substrate loading station to place a carrier onto the conveyor system and a maximum time required by the second substrate loading station to remove a carrier from the conveyor system.

23. A method, comprising: providing a plurality of substrate loading stations each adapted to receive substrate carriers; providing a delivery system adapted to transport substrate carriers between the substrate loading stations, the delivery system including a plurality of carrier supports each adapted to support a substrate carrier; providing a control system for controlling transport of substrate carriers between the substrate loading stations; employing the control system to send a transfer command to a first substrate loading station; if the control system is unable to assign a carrier support for a transfer from the first substrate loading station, employing the control system to send a command to the first substrate loading station to cancel the transfer; and employing the control system to retransmit the transfer command to the first substrate loading station after at least one of a delay and a status of one or more carrier supports changes.

24. The method of claim 23 further comprising, in response to a retransmitted transfer command: assigning a carrier support for the transfer from the first substrate loading station; moving the carrier from the first substrate loading station; and moving the carrier to a second substrate loading station.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is also related to the following commonly-assigned, co-pending U.S. Patent Applications, each of which is hereby incorporated by reference herein in its entirety:

• • U.S. patent application Ser. No. 11/067,302, filed Feb. 25, 2005 and titled “METHODS AND APPARATUS FOR ENHANCED OPERATION OF SUBSTRATE CARRIER HANDLERS”;
  • U.S. patent application Ser. No. 11/067,311, filed Feb. 25, 2005 and titled “METHODS AND APPARATUS FOR MATERIAL CONTROL SYSTEM INTERFACE”; and issued Feb. 13, 2007 as U.S. Pat. Ser. No. 7,177,716;
  • U.S. patent application Ser. No. 11/067,303, filed Feb. 25, 2005 and titled “METHODS AND APPARATUS FOR ELECTRONIC DEVICE MANUFACTURING SYSTEM MONITORING AND CONTROL”;
  • U.S. patent application Ser. No. 10/650,310, filed Aug. 28, 2003 and titled “SYSTEM FOR TRANSPORTING SUBSTRATE CARRIERS”;
  • U.S. patent application Ser. No. 10/764,982, filed Jan. 26, 2004 and titled “METHODS AND APPARATUS FOR TRANSPORTING SUBSTRATE CARRIERS”;
  • U.S. patent application Ser. No. 10/650,480, filed Aug. 28, 2003 and titled “SUBSTRATE CARRIER HANDLER THAT UNLOADS SUBSTRATE CARRIERS DIRECTLY FROM A MOVING CONVEYOR”; and
  • U.S. patent application Ser. No. 10/987,955, filed Nov. 12, 2004 and titled “BREAK-AWAY POSITIONING CONVEYOR MOUNT FOR ACCOMMODATING CONVEYOR BELT BENDS”.

FIELD OF THE INVENTION

The present invention relates generally to electronic device manufacturing, and is more particularly concerned with methods and apparatus for transferring a substrate carrier within an electronic device manufacturing facility.

BACKGROUND

An electronic device manufacturing facility may include conventional systems for transferring substrate carriers about the facility during manufacturing. However, such conventional systems may inefficiently transfer the carriers. Accordingly, improved methods and apparatus for transferring a substrate carrier within an electronic device manufacturing facility are desired.

SUMMARY OF THE INVENTION

In a first aspect of the invention, a first method is provided for electronic device manufacturing. The first method includes the steps of (1) receiving a request to transfer a carrier from a first substrate loading station to a second substrate loading station of an electronic device manufacturing facility including a plurality of substrate loading stations, wherein the facility further includes a plurality of carrier supports coupled to a conveyor system adapted to move the carrier within the facility; (2) assigning one of the plurality of carrier supports to transfer the carrier from the first substrate loading station to the second substrate loading station such that at least one of a time required for the transfer is reduced and balance of the conveyor system is maintained; (3) moving the carrier from the first substrate loading station; and (4) moving the carrier to the second substrate loading station.

In a second aspect of the invention, a second method is provided. The second method includes the steps of (1) providing a plurality of substrate loading stations each adapted to receive substrate carriers; (2) providing a delivery system adapted to transport substrate carriers between the substrate loading stations, the delivery system including a plurality of carrier supports each adapted to support a substrate carrier; (3) providing a control system for controlling transport of substrate carriers between the substrate loading stations; (4) employing the control system to send a transfer command to a first substrate loading station; (5) if the control system is unable to assign a carrier support for a transfer from the first substrate loading station, employing the control system to send a command to the first substrate loading station to cancel the transfer; and (6) employing the control system to retransmit the transfer command to the first substrate loading station after at least one of a delay and a status of one or more carrier supports changes.

In a third aspect of the invention, an apparatus is provided for electronic device manufacturing. The apparatus includes a control system of an electronic device manufacturing facility adapted to (1) receive a request to transfer a carrier from a first substrate loading station to a second substrate loading station of the facility, wherein the facility further includes a plurality of carrier supports coupled to a conveyor system adapted to move the carrier within the facility; (2) assign one of the plurality of carrier supports to transfer the carrier from the first substrate loading station to the second substrate loading station such that at least one of a time required for the transfer is reduced and balance of the conveyor system is maintained; (3) move the carrier from the first substrate loading station; and (4) move the carrier to the second substrate loading station.

In a fourth aspect of the invention, a system is provided for electronic device manufacturing. The system includes (1) a plurality of substrate loading stations included in an electronic device manufacturing facility; (2) an conveyor system, having a plurality of carrier supports coupled thereto, and adapted to move a carrier within the facility; and (3) a control system coupled to the plurality of substrate loading stations and the conveyor system. The control system is adapted to (a) receive a request to transfer a carrier from a first substrate loading station to a second substrate loading station; (b) assign one of the plurality of carrier supports to transfer the carrier from the first substrate loading station to the second substrate loading station such that at least one of a time required for the transfer is reduced and balance of the conveyor system is maintained; (c) move the carrier from the first substrate loading station; and (d) move the carrier to the second substrate loading station. Numerous other aspects are provided in accordance with these and other aspects of the invention.

Other features and aspects of the present invention will become more fully apparent from the following detailed description, the appended claims and the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a schematic top view of an exemplary conveyor system comprising a band (or ribbon) that forms a simple loop within a portion of an electronic device manufacturing facility in accordance with an embodiment of the present invention.

FIG. 1B is a block diagram of a control system included in the exemplary continuously moving conveyor system in accordance with an embodiment of the present invention.

FIG. 2 illustrates a method for transferring a substrate carrier within the facility in accordance with an embodiment of the present invention.

FIG. 3 illustrates a first exemplary method for assigning a carrier support when transferring a substrate carrier within the facility in accordance with an embodiment of the present invention.

FIG. 4 illustrates a second exemplary method for assigning a carrier support when transferring a substrate carrier within the facility in accordance with an embodiment of the present invention.

FIG. 5 is a block diagram of an exemplary apparatus for transferring a substrate carrier within the facility during operation in accordance with an embodiment of the present invention.

FIG. 6 illustrates handshaking while initiating a substrate carrier transfer within the facility in which a carrier support is successfully assigned in accordance with an embodiment of the present invention.

FIGS. 7A and 7B illustrate handshaking while initiating a substrate carrier transfer within the facility in which a carrier support is unsuccessfully assigned in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

An electronic device manufacturing facility may use an overhead transport system (OHT system) that includes a plurality of carrier supports coupled to a moving conveyor system adapted to transfer one or more substrate carriers within the electronic device manufacturing facility. Further, such a facility may include tools adapted to process an electronic device during electronic device manufacturing. Each processing tool may be coupled to a respective substrate loading station adapted to transfer a carrier between the processing tool and the moving conveyor system. More specifically, each processing tool may be coupled to a respective substrate loading station adapted to transfer a carrier between the processing tool and a carrier support coupled to the moving OHT system. In this manner, a carrier may be transferred within the facility.

The present invention provides methods and apparatus for assigning a carrier support for transferring a carrier within the facility. The features of the present invention are particularly advantageous with the use of single or small lot size substrate carriers. As used herein, the term “small lot size” substrate carrier or “small lot” carrier may refer to a carrier that is adapted to hold fewer substrates than a conventional “large lot size” carrier which typically holds thirteen or twenty-five substrates. As an example, a small lot size carrier may be adapted to hold five or less substrates. In some embodiments, other small lot size carriers may be employed (e.g., small lot size carriers that hold one, two, three, four or more than five substrates, but less than that of a large lot size carrier). In general, each small lot size carrier may hold too few substrates for human transport of carriers to be viable within an electronic device or other manufacturing facility.

An algorithm may be employed for assigning the carrier support such that at least one of a time required for the transfer is reduced and balance of the conveyor system is maintained. In this manner, the carrier may be transferred within the facility more efficiently than in conventional electronic device manufacturing systems, thereby improving electronic device manufacturing throughput compared to such conventional systems. For example, the algorithm may select one of the plurality of carrier supports to transfer or deliver a carrier from a first substrate loading station (e.g., a source substrate loading station) to a second substrate loading station (e.g., a destination substrate loading station). The algorithm may determine whether employing the selected carrier support will conflict with a pending transfer (e.g., within the facility). If so, the algorithm may select another carrier support from the plurality of carrier supports and make a similar determination for such carrier support. If the algorithm determines that employing the selected carrier support will not conflict with a pending transfer, the selected carrier support may be assigned for transferring the carrier from the first substrate loading station to the second substrate loading station.

In this manner, the present methods and apparatus may assign a carrier support for transferring a carrier within the facility such that, when the assigned carrier support arrives at the first substrate loading station, the first substrate loading station is prepared to place the carrier onto the moving conveyor system using the assigned carrier support, and when the assigned carrier support arrives at the second substrate loading station, the second substrate loading station is prepared to remove the carrier from the moving conveyor (e.g., from the assigned carrier support coupled thereto). In this manner, the number of times the assigned carrier support on the moving conveyor must be transferred to the first substrate loading station before the first substrate loading station is prepared to place a carrier on the carrier support and/or the number of times the assigned carrier support (along with the carrier coupled thereto) must be transferred to the second substrate loading station before the second substrate loading station is prepared to remove the carrier from the carrier support may be reduced.

The algorithm may determine whether employing the selected carrier support will unbalance the conveyor system, and may assign a carrier support based thereon. In this manner, the algorithm may assign a carrier support for transferring a carrier within the facility such that the moving conveyor system remains balanced (e.g., is not overloaded at any particular portions by carrier supports supporting carriers thereon) thereby reducing excessive stress on portions of the moving conveyor system, which may adversely affect electronic device manufacturing. Consequently, the present methods and apparatus may transfer a carrier more efficiently than in conventional electronic device manufacturing systems, thereby improving manufacturing throughput compared to conventional systems.

Previously incorporated U.S. patent application Ser. No. 10/650,310, filed Aug. 28, 2003 and titled “System For Transporting Substrate Carriers”, discloses a substrate carrier transport system or similar delivery system that includes a conveyor for substrate carriers that is intended to be constantly in motion during operation of the fabrication facility which it serves. The constantly moving conveyor is intended to facilitate transportation of substrates within the fabrication facility so as to reduce the total “dwell” time of each substrate in the fabrication facility.

To operate a fabrication facility in this manner, methods and apparatus should be provided for unloading substrate carriers from the conveyor, and for loading substrate carriers onto the conveyor, while the conveyor is in motion. Previously incorporated U.S. patent application Ser. No. 10/650,480, filed Aug. 28, 2003 and titled “Substrate Carrier Handler That Unloads Substrate Carriers Directly From a Moving Conveyor”, discloses a substrate carrier handler at a substrate loading station or “substrate loading station” that may perform such loading/unloading operations with respect to a moving conveyor. For example, a substrate loading station or substrate loading station may include a horizontal guide or crane that is moveable vertically, and an end effector that is moveable horizontally along the horizontal guide. Other configurations for moving the end effector vertically and/or horizontally are provided.

To unload a substrate carrier from a moving conveyor that transfers substrate carriers (a “substrate carrier conveyor”) and that passes by the substrate loading station, the end effector is moved horizontally at a velocity that substantially matches the velocity of the substrate carrier as it is being transported by the substrate carrier conveyor (e.g., by substantially matching substrate carrier speed in a horizontal direction). In addition, the end effector may be maintained in a position adjacent the substrate carrier as the substrate carrier is being transported. The end effector thus may substantially match a position of the substrate carrier while substantially matching a velocity of the substrate carrier. Likewise, conveyor position and/or velocity may be substantially matched.

While the end effector substantially matches the substrate carrier's velocity (and/or position), the end effector is raised so that the end effector contacts the substrate carrier and disengages the substrate carrier from the substrate carrier conveyor. A substrate carrier similarly may be loaded onto the moving substrate carrier conveyor by substantially matching end effector and conveyor velocities (and/or positions) during loading. In at least one embodiment, such substrate carrier handoffs between the end effector and substrate carrier conveyor are performed at a substantially zero velocity and/or acceleration between the end effector and the substrate carrier.

Previously incorporated U.S. patent application Ser. No. 10/764,982, filed Jan. 26, 2004 and titled “Methods and Apparatus for Transporting Substrate Carriers”, describes a conveyor system that may be employed with the above-described substrate carrier transport system and/or substrate loading station for transporting substrate carriers between one or more processing tools of a semiconductor device manufacturing facility. The conveyor system may include a ribbon (or “band”) that forms a closed loop within at least a portion of the semiconductor device manufacturing facility and that transports substrate carriers therein. In one or more embodiments, the ribbon or band may be formed from stainless steel, polycarbonate, composite materials (e.g., carbon graphite, fiberglass, etc.), steel or otherwise reinforced polyurethane, epoxy laminates, plastic or polymer materials that include stainless steel, fabric (e.g., carbon fiber, fiberglass, Kevlar® available from DuPont, polyethylene, steel mesh, etc.) or another stiffening material, etc. By orienting the ribbon so that a thick portion of the ribbon resides within a vertical plane and a thin portion of the ribbon resides within a horizontal plane, the ribbon is flexible in the horizontal plane and rigid in the vertical plane. Such a configuration allows the conveyor to be constructed and implemented inexpensively. For example, the ribbon requires little material to construct, is easy to fabricate and, due to its vertical rigidity/strength, can support the weight of numerous substrate carriers without supplemental support structure (such as rollers or other similar mechanisms used in conventional, horizontally-oriented belt-type conveyor systems). Furthermore, the conveyor system is highly customizable because the ribbon may be bent, bowed or otherwise shaped into numerous configurations due to its lateral flexibility.

FIG. 1A is a schematic top view of an exemplary conveyor system 101 comprising a band (or ribbon) 103 that forms a simple loop 105 within a portion of an electronic device (e.g., semiconductor device) manufacturing facility 107 in accordance with an embodiment of the present invention. The band 103 may comprise, for example, one of the ribbons described in U.S. patent application Ser. No. 10/764,982, filed Jan. 26, 2004 and titled “Methods and Apparatus for Transporting Substrate Carriers”. The band 103 transports substrate carriers (not shown in FIG. 1A) between processing tools 109 via respective carrier supports 110 coupled to the band 103 , and comprises straight portions 111 and curved portions 113 to form the (closed) loop 105 . Other number of processing tools 109 and/or loop configurations may be employed.

Each processing tool 109 may include a substrate carrier handler at a substrate loading station 115 (e.g., a “tool station”) of the processing tool 109 , for unloading a substrate carrier from, or for loading a substrate carrier onto, the moving band 103 of the conveyor system 101 as the band 103 passes by the substrate loading station 115 (as described in U.S. patent application Ser. No. 10/650,480, filed Aug. 28, 2003 and titled “Substrate Carrier Handler That Unloads Substrate Carriers Directly From a Moving Conveyor”. For example, an end effector (not separately shown) of a substrate loading station 115 may be moved horizontally at a velocity that substantially matches the velocity of the substrate carrier as it is being transported by the band 103 , maintained in a position adjacent the substrate carrier as the substrate carrier is being transported and raised so that the end effector contacts the substrate carrier and disengages the substrate carrier from the conveyor system 101 . A substrate carrier similarly may be loaded onto the moving band 103 by substantially matching end effector and band velocities (and/or positions) during loading.

Each substrate loading station 115 may include one or more load ports or similar locations where substrates or substrate carriers are placed for transfer to and/or from a processing tool 109 (e.g., one or more docking stations, although transfer locations that do not employ docking/undocking movement may be employed). Various substrate carrier storage locations also may be provided at each substrate loading station 115 for substrate carrier buffering at a processing tool 109 .

The conveyor system 101 includes a transport system controller (TSC) 117 for controlling operation of the band 103 . For example, the TSC 117 may control/monitor the speed or velocity and/or status of the band 103 , allocate carrier supports 110 of the band that are used to support/transport substrate carriers, monitor status of the carrier supports 110 , monitor status of band motors/drives, provide such information to each substrate loading station 115 or the like. Additionally or alternatively, as described in detail below, the TSC 117 may employ an algorithm to assign or allocate carrier supports 110 for transporting carriers. Likewise, each substrate loading station 115 may include substrate loading station software (LSS) 119 for controlling substrate loading station operation (e.g., loading or unloading of substrate carriers to/from the conveyor system 101 , transporting of substrate carriers to/from load ports or storage locations of the substrate loading station 115 and/or processing tool 109 serviced by the substrate loading station 115 , etc.). For example, the LSS 119 a–f may operate with a substrate loading station controller (e.g., an intercept controller, not shown). A host/material control system (MCS) 121 communicates with the transport system controller 117 and the substrate loading station software 119 a–f of each substrate loading station 115 for affecting operation of the same. In this manner, the TSC 117 may be adapted to interface with the MCS 121 , substrate loading stations and/or transfer stations of the facility to perform intra-bay and/or inter-bay carrier transfers. The TSC 117 , each LSS 119 a–f and/or the MCS 121 may include a scheduler (not shown) for controlling scheduling of the operations performed by the TSC 117 , LSS 119 a–f and/or the MCS 121 .

The above system is especially well suited for transferring small lot size substrate carriers, such as substrate carriers that hold a single substrate or substantially fewer than 25 substrates.

FIG. 1B is a block diagram of a control system included in the exemplary continuously moving conveyor system in accordance with an embodiment of the present invention. With reference to FIG. 1B, the LSS 119 a–f corresponding to each processing tool 109 , the TSC 117 and MCS 121 may form a control system 123 adapted to control operation of the continuously moving conveyor system 101 . Details of how the control system 123 operates, and more specifically, how the control system 123 may cause the conveyor system 101 to transfer a substrate carrier within the facility in accordance with an embodiment of the present invention are described below with reference to FIGS. 2–7.

FIG. 2 illustrates a method for transferring a substrate carrier within the facility in accordance with an embodiment of the present invention. With reference to FIG. 2, in step 203 , the method 201 begins. In step 205 , a request to transfer a carrier from a first substrate loading station to a second substrate loading station of an electronic device manufacturing facility including a plurality of substrate loading stations may be received, wherein the facility further includes a plurality of carrier supports 110 coupled to a conveyor system adapted to move the carrier within the facility. More specifically, the MCS 121 may issue a request to transfer a specified substrate carrier between the first and second substrate loading stations. The TSC 117 may receive the request from the MCS 121 . In response to receiving the request, the TSC 117 may communicate with the first and/or second substrate loading stations. Details of exemplary communication between the TSC 117 and the first and/or second substrate loading stations are described below with reference to FIGS. 6 and 7.

In step 207 , one of the plurality of carrier supports 110 may be assigned to transfer the carrier from the first substrate loading station to the second substrate loading station such that at least one of a time required for the transfer is reduced and balance of the conveyor system is maintained. For example, the TSC 117 may assign one of the plurality of carrier supports 110 to transfer the carrier from the first substrate loading station to the second substrate loading station such that a time required for the transfer is reduced and/or balance of the conveyor system is maintained. In other words, if the control system 123 , or any part thereof, determines that either (1) the assignment conflicts with a pending transfer; or (2) the assignment will result in an unacceptable distribution of carriers (e.g., a high density of carriers in a single portion of the band 103 as compared to another portion), the TSC 117 may assign a different carrier support 110 (e.g., one that avoids the conflict or imbalance) to transfer the carrier. By reducing the time required for the transfer in this manner, the operating efficiency of the facility and/or the conveyor system 101 included therein may be increased. Additionally or alternatively, reducing the time required for the transfer in this manner may increase the manufacturing throughput of the facility.

By maintaining the balance of the conveyor system, the control system 123 may reduce overloading of one or more portions of the moving conveyor system 101 , such as one or more portions of the band 103 . Requiring the moving conveyor system 101 to support an unbalanced load (or an unacceptable density of carriers) may place excessive stress on the band 103 . The control system 123 may assign carrier supports 110 such that excessive stress on the band 103 is avoided. By reducing excessive stress on one or more portions of the moving conveyor system 101 , the reliability of the conveyor system 101 increases, thereby reducing conveyor system 101 down time. Consequently, the control system 123 may cause a carrier to be transferred more efficiently, thereby improving manufacturing throughput compared to conventional systems.

In some embodiments, the TSC 117 may employ an algorithm to assign one of the plurality of carrier supports to transfer the carrier from the first substrate loading station to the second substrate loading station such that at least one of a time required for the transfer is reduced and balance of the conveyor system is maintained. Details of exemplary methods for assigning one of the plurality of carrier supports to transfer the carrier from the first substrate loading station to the second substrate loading station such that a time required for the transfer is reduced and/or balance of the conveyor system is maintained are described below with reference to FIGS. 3 and 4, which illustrate first and second exemplary methods, respectively, for assigning a carrier support when transferring a substrate carrier within the facility in accordance with an embodiment of the present invention.

In step 209 , the carrier may be moved from the first substrate loading station. More specifically, the control system 123 may cause the carrier to be removed from the first substrate loading station and placed onto the assigned carrier support. Once the carrier is placed on the assigned carrier support, the moving conveyor system 101 may transfer the carrier from the first substrate loading station.

In step 211 , the carrier may be moved to the second substrate loading station. More specifically, the control system 123 may cause the conveyor system 101 to move the carrier toward the second substrate loading station. The control system 123 may cause the carrier to be removed from the carrier support when the carrier support arrives at the second substrate loading station and transferred to the second substrate loading station.

Thereafter, step 213 is performed. In step 213 , the method 201 ends. Through the use of the method 201 of FIG. 2, a carrier may be transferred more efficiently and manufacturing throughput may be improved.

FIG. 3 illustrates a first exemplary method for assigning a carrier support when transferring a substrate carrier within the facility in accordance with an embodiment of the present invention. With reference to FIG. 3, in step 303 , the method 301 begins. In step 305 , one of a plurality of carrier supports may be selected to transfer a carrier from a first substrate loading station to a second substrate loading station of an electronic device manufacturing facility including a plurality of substrate loading stations, wherein the plurality of carrier supports are coupled to a conveyor system adapted to move carriers about the facility. For example, the control system 123 may select one of the plurality of carrier supports based on a previous transfer at the first substrate loading station. More specifically, the control system 123 may select one of the plurality of carrier supports based on a carrier support employed for the preceding transfer at the substrate loading station. However, the control system 123 may select one of the plurality of carrier supports based on additional and/or different factors.

In step 307 , it is determined whether employing the selected carrier support will conflict with a pending transfer. More specifically, the control system 123 may determine whether employing the selected carrier support to transfer the carrier between the first substrate loading station and the second substrate loading station will conflict with any pending carrier transfer between substrate loading stations of the facility. For example, the control system 123 may determine whether employing the selected carrier support to transfer the carrier from the first substrate loading station to the second substrate loading station may cause a delay in and/or failure of any pending carrier transfer between substrate loading stations of the facility.

If, in step 307 , it is determined that employing the selected carrier support conflicts with a pending transfer, step 309 may be performed. In step 309 , another carrier support may be selected from the plurality of carrier supports. More specifically, the control system 123 may select a remaining one of the carrier supports from the plurality of carrier supports. In some embodiments, the control system 123 may select the carrier support adjacent and upstream from the previously-selected carrier support on the moving conveyor system 101 . However, in other embodiments, another carrier support may be selected from the plurality of carrier supports in a different manner. Thereafter, step 307 may be performed. As described above, in step 307 it may be determined whether employing the selected carrier support will conflict with a pending transfer. More specifically, the control system 123 may determine whether the other carrier support (e.g., a remaining one of the plurality of carrier supports) selected from the plurality of carrier supports will conflict with any pending carrier transfer between substrate loading stations.

Alternatively, if, in step 307 , it is determined that employing the selected carrier support will not conflict with a pending transfer, step 311 may be performed. In step 311 , the selected carrier support may be assigned for transferring the carrier from the first substrate loading station to the second substrate loading station. Because the control system 123 determines that employing the selected carrier support for the carrier transfer will not conflict with a pending transfer before assigning such carrier support, once assigned, the carrier support will transfer the carrier from the first substrate loading station to the second substrate loading station without conflicting with any pending transfers. For example, the carrier transfer using the assigned carrier support will not cause a delay in and/or failure of any pending transfers.

Thereafter, step 313 may be performed. In step 313 , the method 301 ends.

In some embodiments, in addition to or as an alternative to step 307 , it is determined whether employing the selected carrier support will unbalance the conveyor system 101 . For example, it is determined whether employing the selected carrier support to transfer the carrier from the first substrate loading station to the second substrate loading station will overload one or more portions of the moving conveyor system 101 , thereby potentially placing excessive stress on such portions.

In such embodiments, if it is determined employing the selected carrier support will unbalance the conveyor system 101 , step 309 may be performed. As stated, in step 309 another carrier support from the plurality of carrier supports may be selected.

Alternatively, in such embodiments, if it is determined employing the selected carrier support will not unbalance the conveyor system 101 , step 311 may be performed. As stated, in step 311 , the selected carrier support may be assigned for transferring the carrier from the first substrate loading station to the second substrate loading station.

Through use of the method 301 , one of a plurality of carrier supports may be assigned to transfer a carrier from the first substrate loading station to the second substrate loading station such that at least one of a time required for the transfer is reduced and balance of the conveyor system is maintained. Consequently, the control system 123 may cause a carrier to be transferred more efficiently and manufacturing throughput may be improved. For example, the TSC 117 may assign carrier supports for transferring carriers between substrate loading stations such that the following system-level requirements may be met: (1) when the assigned carrier support arrives at the first (e.g., source) substrate loading station, the source substrate loading station is ready to place a carrier onto the carrier support, and when the assigned carrier support arrives at the second (e.g., destination) substrate loading station, the destination substrate loading station is ready to remove the carrier from the carrier support; (2) the loading of carriers on the band 103 (e.g., onto assigned carrier supports coupled to the band 103 ) may not affect the ability of the TSC 117 to control the velocity of the band 103 ; and/or (3) the loading of the carriers on the band 103 (e.g., onto assigned carrier supports coupled to the band 103 ) may not affect the reliability of the band 103 . In this manner, the TSC 117 may avoid situations which may adversely affect overall system throughput (e.g., of the conveyor system 101 ). For example, the TSC 117 may avoid a situation in which the destination substrate loading station (e.g., the substrate loading station that will receive the carrier) is not ready to remove the carrier from an assigned carrier support when the carrier support arrives at the substrate loading station, and therefore, the destination substrate loading station will be forced to wait for one complete revolution of the band 103 before such substrate loading station may remove the carrier from the band 103 because the carrier is already on the band 103 , and a manufacturing execution system (MES), which may track carriers within the facility, has assigned the carrier to the destination substrate loading station. Further, the TSC 117 may avoid a situation in which the source substrate loading station (e.g., the substrate loading station that provides the carrier) is not ready to place the carrier onto an assigned carrier support when the carrier support arrives at the substrate loading station, and therefore, the transfer may have to be aborted, and thereafter, a new carrier support assigned for the transfer.

Additionally or alternatively, the TSC 117 may assign carrier supports such that the loading of carriers on the band 103 does not affect the ability of the TSC 117 to control the velocity of the band 103 to within, for example, 0.04% of a desired velocity (although a larger or smaller tolerance may be employed). Additionally or alternatively, the TSC 117 may assign carrier supports for supporting carriers such that the loading of the carriers on the band 103 is not uneven. Uneven loading of carriers on the band 103 may create stress, particularly at bends in the band 103 , and may adversely affect the reliability of the band 103 .

FIG. 4 illustrates a second exemplary method for assigning a carrier support when transferring a substrate carrier within the facility in accordance with an embodiment of the present invention. With reference to FIG. 4, in step 403 , the method 401 begins. In step 405 , one of the plurality of carrier supports may be selected for transferring the carrier from a first substrate loading station to a second substrate loading station. For example, the control system 123 may select a first carrier support for the transfer. The control system 123 may select the first carrier support that may be employed for the transfer based on (1) the last carrier support to enter the first substrate loading station, (2) a maximum time required by the first substrate loading station after using a crane (e.g., to remove a carrier from or place a carrier onto the moving conveyor system 101 ) to reposition the crane to place a carrier onto the conveyor system 101 , (3) a spacing between adjacent carrier supports on the conveyor system 101 and/or (4) a velocity of the conveyor system 101 . In this manner, the control system 123 may select the first carrier support that will arrive at the first substrate loading station once the first substrate loading station is ready to place the desired carrier thereon (e.g., that will result in the first substrate loading station having to wait the least amount of time).

In step 407 , it is determined whether the selected carrier support is available. A carrier support is available if the carrier support is (1) empty; and (2) not assigned for a transfer. A carrier support is empty if the carrier support is not supporting a carrier thereon. A carrier support is not assigned for a transfer if the control system 123 has not already assigned the carrier support to transfer a carrier between substrate loading stations of the facility. The availability of a carrier support may be based on a larger or smaller number of factors and/or different factors. For example, in some embodiments, a carrier support is available if the carrier support will be (1) empty; (2) not assigned for a transfer; and (3) acceptable to a band loading algorithm, all at the time the carrier support arrives at the intended substrate loading station for loading. The band loading algorithm may be employed by the control system 123 to maintain balance of the conveyor system 101 . A carrier support may be acceptable to the band loading algorithm if employing the carrier support to transfer a carrier will not unbalance (e.g., unevenly load) the conveyor system 101 . Employing a carrier support that is supporting a carrier thereon or a carrier support already assigned to transfer another carrier for the transfer may cause a delay in and/or failure of one or more transfers within the facility. Therefore, by determining whether the selected carrier support is available or will be available, the control system 123 may determine whether employing such carrier support will conflict with a pending transfer between substrate loading stations of the facility.

If, in step 407 , it is determined the selected carrier support is not available, step 409 may be performed. In step 409 , the control system 123 may select another carrier support. For example, the control system 123 may select the next adjacent carrier support (e.g., upstream) from the previously-selected carrier support. In this manner, the control system 123 may increment to the next carrier support of the plurality of carrier supports coupled to the conveyor system 101 .

In step 411 , it is determined whether all carrier supports in the plurality of carrier supports have been selected and determined to be unavailable. For example, the control system 123 may determine a previously-selected carrier support (e.g., the first carrier support that may be employed for the transfer) has been selected again. If, in step 411 , the control system 123 determines all carrier supports have been selected and determined to be unavailable, no carrier supports in the plurality of carrier supports may be employed for the transfer. Therefore, step 413 may be performed. In step 413 , a command to abort the transfer may be sent to the first substrate loading station. More specifically, because none of the carrier supports may currently be employed for the transfer, the control system 123 may abort the transfer. For example, the control system 123 may issue a request to transfer the carrier between the first substrate loading station and the second substrate loading station at later time.

Thereafter, step 429 may be performed. In step 429 , the method 401 ends.

Alternatively, if, in step 411 , it is determined that all carrier supports in the plurality of carrier supports have not been selected, step 407 may be performed. As stated, in step 407 , it is determined whether the selected carrier support is available. More specifically, the control system 123 may determine whether the other carrier support selected in step 409 is available. In this manner, the control system 123 may increment through the plurality of carrier supports until an available carrier support is selected or the control system 123 determines no carrier supports are available for the transfer.

Alternatively, if, in step 407 , it is determined the selected carrier support is available, step 415 may be performed. In step 415 , the next carrier support assigned for a transfer at the first substrate loading station is identified. More specifically, each substrate loading station 115 (e.g., the first substrate loading station) may include a list of transfers pending at that substrate loading station 115 . Each transfer pending at a substrate loading station may be a portion of a carrier transfer between substrate loading stations of the facility (e.g., place carrier X on carrier support X). The list may be stored in memory included in the substrate loading station 115 . An entry in such list may represent a transfer pending at the substrate loading station and may include data such as a carrier support identification and task to be performed (e.g., whether a carrier is to be removed (e.g., picked) from the identified carrier support or placed onto the identified carrier support) by the substrate loading station. The control system 123 may traverse the list looking for a next entry corresponding to a carrier support assigned for a transfer at the first substrate loading station, such entry may represent the next carrier support assigned for a transfer onto which a carrier may be placed or from which the carrier may be removed by the substrate loading station.

In step 417 , it is determined whether a next carrier support assigned for a transfer at the first substrate loading station is identified. More specifically, it is determined whether the control system 123 found an entry in the list included in the first substrate loading station.

If, in step 417 , it is determined that a next carrier support assigned for a transfer at the first substrate loading station is identified, step 419 may be performed. In step 419 , it is determined whether spacing on either side of the carrier support assigned for a transfer at the first substrate loading station remains acceptable if the selected carrier support is assigned for the transfer between the first and second substrate loading stations. The control system 123 may determine whether spacing on either side of the carrier support for a transfer at the first substrate loading station identified by the entry from the list remains acceptable if the selected carrier support is assigned for the transfer between the first and second substrate loading stations. Spacing may refer to a distance between adjacent carrier supports assigned for a transfer (e.g., a pick or place) at a substrate loading station. At the first substrate loading station, which may serve as a source substrate loading station for the selected carrier support, a value for acceptable spacing on either side of a carrier support may be calculated as follows:

• • If pick from the carrier support Then
    1+round((BandVelocity/CarrierSupportSpacing*(Max imumPickTime+MaximumPrepareToPlaceTime)))
  • Else (must be a place to the carrier support)
    1+round((BandVelocity/CarrierSupportSpacing*(Max imumPlaceTime+MaximumPrepareToPlaceTime)))
  • Endif
    wherein:
  • BandVelocity is the velocity of the conveyor system 101 ;
  • CarrierSupportSpacing is the distance between adjacent carrier supports on the conveyor system 101 ;
  • MaximumPickTime is a maximum time required by the substrate loading station to remove a carrier from a carrier support;
  • MaximumPrepareToPlaceTime is a maximum time required by the substrate loading station to position itself to prepare to place a carrier on the conveyor system 101 ; and
  • MaximumPlaceTime is a maximum time required by the substrate loading station to place a carrier onto the conveyor system 101 .

Therefore, if the first substrate loading station will remove a carrier from the identified carrier support, the appropriate spacing on either side of such carrier support may be equal to 1+a product of the velocity of the conveyor system divided by the distance between adjacent carrier supports on the conveyor system and the sum of the maximum time required by the substrate loading station to remove a carrier from a carrier support and the maximum time required by the substrate loading station to position itself to prepare to place a carrier on the conveyor system rounded up (e.g., to an integer value).

Alternatively, if the first substrate loading station will place a carrier onto the identified carrier support, the appropriate spacing on either side of such carrier support may be equal to 1+a product of the velocity of the conveyor system divided by the distance between adjacent carrier supports on the conveyor system and the sum of the maximum time required by the substrate loading station to place a carrier onto a carrier support and the maximum time required by the substrate loading station to position itself to prepare to place a carrier on the conveyor system rounded up (e.g., to an integer value).

The control system 123 may employ the acceptable spacing value to determine whether spacing on either side of the carrier support identified for a transfer at the first substrate loading station (e.g., a carrier support identified in the list of pending transfers stored at the first substrate loading station) remains acceptable if the selected carrier (e.g., in step 405 ) support is assigned for the transfer between the first and second substrate loading stations. More specifically, the control system 123 may determine whether the selected carrier support is at least the number of carrier support spaces indicated by the acceptable spacing value away from the identified carrier support.

If the selected carrier support is less than the spacing indicated by the acceptable spacing value away from the identified carrier support, assigning the selected carrier support to transfer a carrier between the first and second substrate loading stations may cause a delay and/or failure of such transfer and/or cause a delay and/or failure of the identified carrier support's transfer at the first substrate loading station. For example, assigning such selected cradle may unbalance the band 103 which may cause a delay and/or failure of the transfer. Therefore, if, in step 419 , it is determined that spacing on either side of the carrier support identified for a transfer at the first substrate loading station does not remain acceptable if the selected carrier support is assigned for the transfer between the first and second substrate loading stations, step 409 may be performed. As stated, in step 409 , the control system 123 may select another carrier support.

However, if the selected carrier support is not less than the spacing indicated by the acceptable spacing value away from the identified carrier support, assigning the selected carrier support to transfer a carrier between the first and second substrate loading stations may not cause a delay and/or failure of such transfer and of the identified carrier support's transfer at the first substrate loading station. Therefore, if, in step 419 , it is determined that spacing on either side of the carrier support identified for a transfer at the first substrate loading station remains acceptable if the selected carrier support is assigned for the transfer between the first and second substrate loading stations, step 415 and thereafter step 417 may be performed. As stated, in step 415 , the next carrier support assigned for a transfer at the first substrate loading station is identified, and in step 417 , it is determined whether a next carrier support assigned for a transfer at the first substrate loading station is identified.

Alternatively, if, in step 417 , it is determined that a next carrier support assigned for a transfer at the first substrate loading station is not identified, the control system 123 may have traversed the entire list of pending transfers at the first substrate loading station. In this manner, the control system 123 may check all pending transfers at the first substrate loading station (e.g., all entries included in the list) and determine that the carrier support selected for transferring a carrier between the first and second substrate loading stations is acceptable to all pending transfers at the first substrate loading station. More specifically, the control system 123 may determine employing the selected carrier support to transfer a carrier between the first and second substrate loading stations will not cause delay and/or failure of any pending transfers at the first substrate loading station. Therefore, step 421 may be performed. In step 421 , the next carrier support assigned for a transfer at the second substrate loading station is identified. As stated, each substrate loading station 115 may include a list of transfers pending at that substrate loading station 115 . Each transfer pending at a substrate loading station may be a portion of a carrier transfer between substrate loading stations of the facility. The list may be stored in memory included in the substrate loading station 115 . An entry in such list may represent a transfer pending at the substrate loading station and may include data such as a carrier support identification and task to be performed (e.g., whether a carrier is to be removed (e.g., picked) from the identified carrier support or placed onto the identified carrier support) by the substrate loading station. In the second substrate loading station, the control system 123 may traverse the list looking for a next entry corresponding to a carrier support assigned for a transfer at the second substrate loading station, which may represent the next carrier support assigned for a transfer onto which a carrier may be placed or from which the carrier may be removed by the second substrate loading station.

In step 423 , it is determined whether a next carrier support assigned for a transfer at the second substrate loading station is identified. More specifically, it is determined whether the control system 123 found another entry in the list included in the second substrate loading station.

If, in step 423 , it is determined that a next carrier support assigned for a transfer at the second substrate loading station is identified, step 425 may be performed. In step 425 , it is determined whether spacing on either side of the carrier support identified for a transfer at the second substrate loading station remains acceptable if the selected carrier support is assigned for transferring a carrier between the first and second substrate loading stations. The control system 123 may determine whether spacing on either side of the carrier support for a transfer at the second substrate loading station identified by the entry from the list remains acceptable if the selected carrier support is assigned for the transfer between the first and second substrate loading stations. As stated, spacing may refer to a distance between adjacent carrier supports assigned for a transfer at a substrate loading station. At the second substrate loading station, which may serve as the destination substrate loading station for the selected carrier support, a value for acceptable spacing on either side of a carrier support may be calculated as follows:

• • If pick from the carrier support Then
    1+round((BandVelocity/CarrierSupportSpacing*(Max imumPickTime+MaximumPrepareToPickTime)))
  • Else (must be a place to the carrier support)
    1+round((BandVelocity/CarrierSupportSpacing*(Max imumPlaceTime+MaximumPrepareToPickTime)))
  • Endif
    wherein MaximumPrepareToPickTime is a maximum time required by the substrate loading station to position itself to prepare to remove a carrier from the conveyor system. Therefore, if the second substrate loading station will remove a carrier from the identified carrier support, the appropriate spacing on either side of such carrier support may be equal to 1+product of the velocity of the conveyor system divided by the distance between adjacent carrier supports on the conveyor system and the sum of the maximum time required by the substrate loading station to remove a carrier from a carrier support and the maximum time required by the substrate loading station to position itself to prepare to remove a carrier from the conveyor system rounded up (e.g., to an integer value).

Alternatively, if the second substrate loading station will place a carrier onto the identified carrier support, the appropriate spacing on either side of such carrier support may be equal to 1+product of the velocity of the conveyor system divided by the distance between adjacent carrier supports on the conveyor system and the sum of the maximum time required by the substrate loading station to place a carrier onto a carrier support and the maximum time required by the substrate loading station to position itself to prepare to remove a carrier from the conveyor system rounded up (e.g., to an integer value).

The control system 123 may employ the acceptable spacing value to determine whether spacing on either side of the carrier support identified for a transfer at the second substrate loading station remains acceptable if the selected carrier support is assigned for the transfer between the first and second substrate loading stations. More specifically, the control system 123 may determine whether the selected carrier support is at least the number of carrier support spaces indicated by the acceptable spacing value away from the identified carrier support.

If the selected carrier support is less than the spacing indicated by the acceptable spacing value away from the identified carrier support, assigning the selected carrier support to transfer a carrier between the first and second substrate loading stations may cause a delay and/or failure of such transfer and/or cause a delay and/or failure of the identified carrier support's transfer at the second substrate loading station. Therefore, if, in step 425 , it is determined that spacing on either side of the carrier support identified for a transfer at the second substrate loading station does not remain acceptable if the selected carrier support is assigned for the transfer between the first and second substrate loading stations, step 409 may be performed. As stated, in step 409 , the control system 123 may select another carrier support.

However, if the selected carrier support is not less than the spacing indicated by the acceptable spacing value away from the identified carrier support, assigning the selected carrier support to transfer a carrier between the first and second substrate loading stations may not cause a delay and/or failure of such transfer and of the identified carrier support's transfer at the second substrate loading station. Therefore, if, in step 425 , it is determined that spacing on either side of the carrier support identified for a transfer at the second substrate loading station remains acceptable if the selected carrier support is assigned for the transfer between the first and second substrate loading stations, step 421 and thereafter step 423 may be performed. As stated, in step 421 , the next carrier support assigned for a transfer at the second substrate loading station is identified, and in step 423 , it is determined whether a next carrier support assigned for a transfer at the second substrate loading station is identified.

Alternatively, if, in step 423 , it is determined that a next carrier support assigned for a transfer at the second substrate loading station is not identified, the control system 123 may have traversed the entire list of pending transfers at the second substrate loading station. In this manner, the control system 123 may check all pending transfers at the second substrate loading station included in the list and determine that the carrier support selected for transferring a carrier between the first and second substrate loading stations is acceptable to all pending transfers at the second substrate loading station. More specifically, the control system 123 may determine employing the selected carrier support to transfer a carrier between the first and second substrate loading stations will not cause delay and/or failure of any pending transfers at the second substrate loading station.

In this manner, the control system 123 may determine that employing the selected carrier support to transfer a carrier between the first and second substrate loading stations will not cause delay and/or failure of any pending transfers at the first and second substrate loading stations. Therefore, step 427 may be performed. In step 427 , the selected carrier support may be assigned to transfer a carrier between the first and second substrate loading stations. The list corresponding to the first substrate loading station may be updated to include an entry identifying the selected carrier support and indicating the first substrate loading station will place a carrier onto the selected carrier support. Similarly, the list corresponding to the second substrate loading station may be updated to include an entry identifying the selected carrier support and indicating the second substrate loading station will remove a carrier from the selected carrier support.

Thereafter, step 429 may be performed. As stated, in step 429 , the method 401 ends. Through use of the method 401 one of the plurality of carrier supports may be assigned to transfer the carrier from a first substrate loading station to a second substrate loading station such that a time required for the transfer is reduced and/or balance of the conveyor system is maintained. For example, by starting at the first possible carrier support that may be available for the transfer, and by selecting an empty carrier support that is not already assigned to a transfer and that will not conflict with any pending transfers at the first and second substrate loading stations, the present methods and apparatus may assign one of the plurality of carrier supports to transfer the carrier from a first substrate loading station to a second substrate loading station such that a time required for the transfer is reduced. Additionally or alternatively, by only assigning carrier supports that are acceptable to the band loading algorithm, the present methods and apparatus may assign one of the plurality of carrier supports to transfer the carrier from a first substrate loading station to a second substrate loading station such that balance of the conveyor system is maintained.

A method for transferring a substrate carrier within the facility which employs the second exemplary method for assigning a carrier support when transferring a substrate carrier within the facility is described below with reference to FIGS. 2 and 4 and with reference to FIG. 5 which is a block diagram of an exemplary apparatus for transferring a substrate carrier within the facility during operation in accordance with an embodiment of the present invention. With reference to FIG. 5, the apparatus 501 may be a moving conveyor system that includes a band 113 . The apparatus may include thirty-three carrier supports, adapted to support a respective carriers, coupled to the band 113 (although a larger or smaller number of carrier supports may be employed). The band 103 may be continuous. For example, a first end 505 of the band 103 may be coupled to a second end 507 of the band 103 at a known point along the band 103 known as the “0th” carrier support. The 0th carrier support of the band 103 is between the first and thirty-third carrier supports 503 (although the 0th carrier support may be located elsewhere along the band 113 ). The apparatus 501 may move one or more carriers 509 above a plurality of substrate loading stations. For example, the apparatus 501 may move carriers above a first through third substrate loading station 511 – 515 (although the apparatus 501 may move the carriers above a larger or smaller number of substrate loading stations 511 – 515 . For the apparatus 501 , a maximum time required by a substrate loading station 511 – 515 to position itself to prepare to place a carrier 509 onto the conveyor system 501 , a maximum time required by the substrate loading station 511 – 515 to position itself to prepare to remove a carrier 509 from the conveyor system 501 , a maximum time required to remove a carrier 509 from the conveyor system 501 and a maximum time required to place a carrier 509 onto the conveyor system 501 is six seconds for each substrate loading station. However, a larger or smaller value may be employed for any of the above parameters for one or more of the substrate loading stations 511 – 515 . Further, the velocity of the band 113 may be 0.5 feet/second in the direction of the arrow 517 (e.g., from the first substrate loading station 511 toward the third substrate loading station 515 ). The space between adjacent carrier supports 503 on the band 103 may be two feet. However, a larger or smaller value may be employed for the band velocity and/or space between adjacent carrier supports.

Further, the following transfers are assumed pending:

Scheduled Transfers (e.g., Picks and Places)
	Picks	Places
At Substrate loading station 1 (SLS1)
	Carrier M from	Carrier 3 to
	Carrier support 30	Carrier support 5
At Substrate loading station 2 (SLS2)
	Carrier G from	Carrier 7 to
	Carrier support 12	Carrier support 18
At Substrate loading station 3 (SLS3)
	Carrier K from	Carrier B to
	Carrier support 24	Carrier support 11.

During operation, for example, during step 205 , the TSC 117 of the control system 123 may receive a new Transfer command from the MCS 121 to move Carrier 4 from SLS 1 to SLS 2 . In response, the first substrate loading station SLS 1 may send an AssignCarrier support command to the TSC 117 which may indicate that the last carrier support to enter the first substrate loading station SLS 1 was Carrier support 3 . Details of the handshaking between the components of the control system 123 and/or one or more substrate loading stations 511 – 515 are described below with reference to FIGS. 6 and 7. Thereafter, during step 207 in which the second exemplary method 401 may be employed, the following process flow may occur:

• • 1. In step 405 , using the formulas described above, the control system 123 may determine the first substrate loading station (e.g., source substrate loading station) may require a spacing of four carrier supports on either side of a carrier support already assigned for a pick or a place.
  • 2. The TSC 117 may assume that the first substrate loading station (e.g., SLS 1 ) requires this four carrier support spacing from the last carrier support (e.g., Carrier support 3 ) that entered the first substrate loading station. Therefore, the TSC 117 starts with Carrier support 33 as the first carrier support that may possibly be used for the transfer. It should be noted the 0th carrier support, while not available to use for transfers, may be taken into account when determining carrier support spacing (although, in some embodiments, the 0th carrier support may not be counted when determining carrier support spacing).
  • 3. In step 407 , is Carrier support 33 available (empty, not assigned to another transfer and acceptable to the band loading algorithm)? Yes.