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:
Dec. 05, 2000
Filed:
May. 07, 1999
Kurt A Carlsen, Burlington, VT (US);
James McManus, Danbury, CT (US);
James Dietz, Danbury, CT (US);
International Business Machines, Armonk, NY (US);
Advanced Technology Materials, Inc., Danbury, CT (US);
Abstract
A sub-atmospheric gas delivery system (100) with a backflow control apparatus (10) for preventing backflow into the sub-atmospheric gas source (14). The gas delivery system includes three fluidly coupled sticks: a purge stick (120), a process gas delivery stick (124) and an evacuation stick (130). The backflow control apparatus comprises a gas line (26) fluidly coupling the sub-atmospheric gas source to a chamber (50), a valve (20) attached to the sub-atmospheric gas source for blocking fluid communication between the gas source and the gas line upon receipt of a first signal, a flow restrictor (R) in fluid communication with the gas line and positioned between the valve and the chamber, and first and second pressure transducers (P1 and P2) in fluid communication with the gas line and positioned on either side of the flow restrictor. Each transducer is capable of generating a signal representative of pressure. The backflow control apparatus further includes a valve controller unit (40) connected to the first and second pressure transducers and the valve. The controller is capable of generating the aforementioned first signal in response to the signals from the first and second pressure transducers.