Process gas distribution system and method with supervisory control

• US 5,220,517 A
• Filed: 08/31/1990
• Issued: 06/15/1993
• Est. Priority Date: 08/31/1990
• Status: Expired due to Term

• Current Assignee: SCI Systems Incorporated (Sanmina-SCI Corporation)
• Original Assignee: SCI Systems Incorporated (Sanmina-SCI Corporation)
• Inventors: Geist, Stephen G., DuRoss, Ronald R., Hayes, Gregory L., Sierk, Dennis A.
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US07/576,067
• Time in Patent Office: 1,019 Days
• Field of Search: 364/550, 364/510, 364/500, 364/138, 364/571.04, 364/479, 364/492, 340/825, 340/825.06, 340/825.08, 340/825.15, 340/825.22, 340/825.23, 251/129.04, 251/289
• US Class Current: 700/282
• CPC Class Codes: F17C 13/02 Special adaptations of indicating, measuring, or monitoring equipment measuring in general G01
• CPC Class Codes: F17C 13/04 Arrangement or mounting of valves valves per se F16K ; snap-coupling of nipples F16L37/00
• CPC Class Codes: F17C 2205/0111 Boxes
• CPC Class Codes: F17C 2205/0176 with ventilation
• CPC Class Codes: F17C 2205/0338 Pressure regulators
• CPC Class Codes: F17C 2205/0391 inside the pressure vessel
• CPC Class Codes: F17C 2227/044 by purging
• CPC Class Codes: F17C 2250/032 using computers
• CPC Class Codes: F17C 2250/034 using wireless transmissions
• CPC Class Codes: F17C 2250/0443 Flow or movement of content
• CPC Class Codes: F17C 2250/0636 Flow or movement of content
• CPC Class Codes: F17C 2270/0518 Semiconductors
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 21/67276 Production flow monitoring, e.g. for increasing throughput program-control systems per se G05B19/00, e.g. total factory control G05B19/418

Abstract

A plurality of gas flow control units in cabinets are connected to distribute process gas, on demand, to a plurality of utilization locations known as "tool" locations in a semi-conductor manufacturing plant. Each gas flow control unit is connected to a single tool interface controller over a single communications cable. The status and operational characteristics of the individual units are communicated through the tool interface controller to a supervisory control computer by means of polling. Each flow control cabinet has its own data processor, and can be operated alone. Also, the supervisory computer can be used to operate each cabinet, as well as to monitor operations of the system. Gas demand and other signals are communicated from each tool location to the control units through a single cable connected to the interface controller, thus reducing the original wiring cost. Changing the communications path to accompany a change of the tool to which a given conduit in one of the cabinets delivers its gas can be done quickly, in software, with a few keystrokes. Mechanical re-wiring is not needed.

Claims

1. In or for a process gas distribution system, said system comprising, in combination, a plurality of gas distribution control units, each containing electrically-operated flow control means for controlling the flow of process gas to at least one utilization location, interface control means located remotely from said control units, communications means for communicating signals between said interface control means and said flow control means, and between said utiization locations and said interface control means, means for identifying each of said flow control means and each of said utilization locations, adn means for communicating signals to selected flow control means in response to signals from a specific one of said utilization locations.

2. A system as in claim 1 including supervisory control computer means connected to said terminal interface control means for communicating status information and control signals between said supervisory contro lcomputer means and each of said flow control means.

3. A system as in claim 2 in which said supervisory computer means includes means for monitoring and controlling the operation of each of said flow contro lmeans, and including means in each of said flwo control means enabling said flow control means to operate independently of said supervisory computer means.

4. A system as in claim 1 in which said interface control means includes means for broadcasting to said flow control means signals responsive to signals from one of said utilization locations, and selective response means for causing said flow control means to respond to the broadcasting signals selectively in accordance with stored data.

5. A system as in claim 1 in which said communications means includes cable means for connecting said interface control means to said flow control means sequentially, and in which said interface control means includes means for sequentially polling each of said flow control means to interrogate and receive signals from each of said flow control means.

6. A system as in claim 1 including process gas flow switching means at each utilization location for use in starting and stopping the flow of process gas to that location from one of said flow control means, said communications means including means connected between said interface control means and each of said switching means for communicating signals therebetween.

7. A system as in claim 6 including data processing terminal means at each of said utilization locations for gathering data at said location and transmitting it to said interface control means in response to polling.

8. A system as in claim 3 including means for causing the direct operation of each of said flow control means to override operational commands from said supervisory computer means.

9. A method for supervisory control at a single station of the operation of a plurality of gas flow control units, said control units being located apart from one another, said method comprising the steps of:

(a) providing a supervisory computer at said station;

(b) providing an interface unit at said station;

(c) communicating signals from a plurality of utilization stations through said interface unit to said flow control units to cause selective operation thereof;

(d) sequentially polling said gas flow control units to transmit to said computer data concerning the operation of said control units;

(e) sending control signals to said control units from said supervisory computer to control operation thereof; and

(f) displaying on display means at said station information regarding the operation of said control units.

10. A method as in claim 9 including controlling the operation of each of said control units either at said supervisory computer, or at the control unit itself, while giving priority to control commands generated at the control unit itself.

11. In or for a process gas distribution system for distributing process gas to spaced-apart gas utilization stations under the control of spaced-apart gas flow control units, said system including communications means for electrically communicating signals between each of said stations and said gas flow control units for controlling the delivery of process gas to each of said stations, there being at least one gas delivery conduit controlled by each of said control units, the improvement of interface means for associating station signals from each gas utilization station with at least one of said gas flow control units to cause process gas to be delivered over a selected gas delivery conduit to that station, and storing means responsive to operator control for storing in memory and changing the association between said station signals and said gas delivery conduits.

12. Apparatus as in claim 11 including means for identifying the station from which said station signals come, memory means for storing a correlation between the station identification and at least one selected gas delivery conduit, and means for causing gas to be delivered from a source through said conduit to the identified station, said storing means comprising means for changing said correlation stored in said memory means.

13. Apparatus as in claim 11 in which said interface means includes means for broadcasting said station signals to a plurality of said gas flow control units, and each of said gas flow control units includes means for reading station-identifying signals transmitted to it, identifying the corresponding gas flow conduit, and causing gas to flow through that conduit.

14. Apparatus as in claim 12 in which said interface means includes a unit having first input/output means for communicating with a plurality of said stations, second input/output means for communicating with a plurality of said gas flow control units, and data processing means for broadcasting the identification of each station requesting initiation or termination of gas flow to said gas flow control units.

15. A method of changing the association of each a plurality of gas delivery conduits with each of a plurality of gas utilization stations to enable the change of electrical control to correspond to gas flow re-routing, said method comprising the steps of:

(a) connecting each of said stations for electrical communication with a terminal unit,

(b) identifying the signals received from said stations on the basis of which station the signals came from,

(c) storing in computer memory data associating specified ones of said gas delivery conduits with specified ones of said stations,

(d) providing electrical communications through said terminal unit between each of said stations and a selected one or more of a plurality of control units remote from said terminal unit, the selection being made on the basis of the stored association data,

(e) changing the connections of said gas delivery conduits to said stations, and

(f) erasing said data from memory and storing new data to provide new associations of stations and conduits corresponding to the gas conduit connection changes.

16. A method as in claim 15 in which said erasing and storing step is performed at each of the remote control units, and said data is periodically transmitted to memory in said terminal unit by polling.

17. A method as in claim 16 in which said data is stored in electrically-erasable programmable read-only memory in said remote control units, and the memory in said terminal unit is volatile random access memory.