The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 20, 2001
Filed:
Jun. 26, 1998
John G. Zvonar, Austin, TX (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
By monitoring the output voltage of a mass flow controller (MFC) there is no way to detect when a MFC is starting to degrade (or beginning to fail) as long as the MFC output voltage is driven to match the MFC setpoint voltage. Only when the MFC actually fails, and the MFC output voltage is unable to be driven to match the MFC setpoint voltage, is the failure detectable. A predictive failure monitoring system for a mass flow controller (MFC) is disclosed which monitors the “valve voltage” of the MFC as well as the MFC output voltage. By knowing the normal relationship between the MFC setpoint voltage and the respective valve voltage, then degradation or other changes may be noticed before the MFC actually fails, and importantly, before production material is ruined by the failing MFC. Such a real-time monitoring capability may be transparently implemented as an add-on module between the MFC and the system controller for the MFC. The add-on module may be advantageously connected between the MFC card edge connector and the system card edge socket which is normally connected to the MFC card edge connector. The module monitors, in real time, the performance of the MFC by measuring the valve voltage on the valve test point. If determined to be outside of various user-settable limits, then warnings and relay closures may be done. The module can also automatically characterize the MFC operation when known to be proper, then go into a “run” mode to monitor operation and provide indications when operation falls outside of user-settable limits.