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:
Aug. 17, 1999
Filed:
Dec. 02, 1997
Jacob H Martin, Wellesley, MA (US);
Varian Inc., Palo Alto, CA (US);
Abstract
The workable range is extended into lower pressure region for micromechanical pressure sensors of the kind having a vibrating mass in proximity of a stationary surface by increasing the amount of squeeze damping. The amount of squeeze damping is increased by using the symmetry of a circular disk-shaped vibrating mass and restricting or changing the flow path of the gas in and out of a squeeze damping space. A circular vibrating mass is supported through an annular spring by a support ring attached to the substrate surface by a plurality of mesas which serve to block the gas flow into and out of the squeeze damping space between the mass and the substrate surface. The amount of squeeze damping may be increased by providing the support ring which completely encloses the squeeze damping space with the vibrating mass having a hole through which the gas may enter and leave the space. A top electrode may be provided above and in close proximity of the vibrating mass to achieve smaller clearances between the substrate electrode and the mass. The vibrating mass may be caused to vibrate parallel to the surface of the substrate in conjunction with a top electrode to measure higher pressures.