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:
May. 25, 2010
Filed:
Dec. 09, 2004
Thomas N. Horsky, Boxborough, MA (US);
Robert W. Milgate, Iii, Gloucester, MA (US);
Thomas N. Horsky, Boxborough, MA (US);
Robert W. Milgate, III, Gloucester, MA (US);
Semequip, Inc., North Billerica, MA (US);
Abstract
A vapor delivery system for delivering a steady flow of sublimated vapor to a vacuum chamber comprises a vaporizer of solid material, a mechanical throttling valve, and a pressure gauge, followed by a vapor conduit to the vacuum chamber. The vapor flow rate is determined by both the temperature of the vaporizer and the setting of the conductance of the mechanical throttle valve located between the vaporizer and the vacuum chamber. The temperature of the vaporizer is determined by closed-loop control to a set-point temperature. The mechanical throttle valve is electrically controlled, e.g. the valve position is under closed-loop control to the output of the pressure gauge. In this way the vapor flow rate can be generally proportional to the pressure gauge output. All surfaces exposed to the vapor from the vaporizer to the vacuum chamber are heated to prevent condensation.