Fluid handling – Line condition change responsive valves – Thermal responsive
Patent
1991-01-07
1991-11-05
Cohan, Alan
Fluid handling
Line condition change responsive valves
Thermal responsive
137486, 1374875, G05D 706
Patent
active
050624466
ABSTRACT:
An intelligent mass flow controller for controlling the mass flow of gas to a semiconductor processing chamber. A sensing circuit measures a difference in temperature across a sensing tube and translates this difference to adjust a valve for controlling the mass flow. A microcontroller which includes a CPU, signal processing and software routines continually monitors the various parameters and provide "on the fly" corrections, as well as providing diagnostics and record retention.
REFERENCES:
patent: 4813443 (1989-03-01), Pounder
patent: 4866940 (1989-09-01), Hwang
patent: 4873873 (1989-10-01), Day
patent: 4976144 (1990-12-01), Fitzgerald
The Journal of Vacuum Science and Technology, May/Jun. 1990, "Toward Understanding the Fundamental Mechanisms and Properties of the Thermal Mass Flow Controller", L. D. Hinkle, C. F. Mariano.
Sierra Instruments Brochure, 1987, "Process Gas Mass Flow Controllers and Meters", Sierra's Side-Trak.TM., Series 840 and 830.
Journal of Scientific Instruments, 1968, "Thermal Methods of Flow Measurement", Series 2, vol. 1, P. Bradshaw.
IEEE Transactions on Instrumentation, Dec. 1974, "Standard Cell Enclosure with 20 -.mu.K Stability", vol. IM-23, No. 4; Robert Cutkosky, B. Field.
Semiconductor International, Sep. 1988, "Watch Your Vacuums and RF by PC to Make Your Process Repeatable," Brian Chapman et al.
Control Engineering, May 1985, "Thermal Mass Flowmeters", pp. 150-158, Brian C. Waters.
Cohan Alan
Kidd William W.
Sematech Inc.
LandOfFree
Intelligent mass flow controller does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Intelligent mass flow controller, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Intelligent mass flow controller will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-493157