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:
Jun. 30, 1998
Filed:
May. 31, 1996
David W Burns, Minneapolis, MN (US);
Thomas G Stratton, Roseville, MN (US);
Honeywell Inc., Minneapolis, MN (US);
Abstract
A temperature sensing device employs a resonant polysilicon beam, in combination with electrical circuitry for oscillating the beam at its natural resonant frequency, to sense changes in temperature. The resonant beam is formed as part of a silicon layer, and the silicon layer is in direct contact with a dissimilar material. In one version of the device, the silicon layer is deposited onto a sapphire substrate by low pressure chemical vapor deposition. In another version, the beam is part of a polysilicon layer deposited onto a silicon wafer substrate. The silicon substrate is thinned, then thermoelectrically bonded to a borosilicate glass substrate. In still another version, the silicon substrate is selectively thinned and has deposited thereon a TCE mismatched material. In all versions, temperature is sensed based on a thermal mismatch of the two dissimilar materials. The respective layers expand (and contract) at different rates in response to temperature changes, altering the level of induced axial strain in the resonant beam. The change in induced strain alters the frequency at which the beam oscillates, thereby providing a direct indication of temperature.