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. 22, 1992
Filed:
Jun. 14, 1991
Karl-Hermann Friese, Leonberg, DE;
Hans-Martin Wiedenmann, Stuttgart, DE;
Gunther Stecher, Ludwigsburg, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A PTC temperature sensor and a process for producing PTC temperature sensing elements from ceramic films for a PTC temperature sensor are proposed. The PTC temperature sensing elements are so designed that the PTC resistor track is hermetically encapsulated with respect to the gas being measured and the ambient air. Ceramic films based on an insulator ceramic, in particular based on Al.sub.2 O.sub.3, and ceramic films based on a solid electrolyte can be used to produce the temperature sensing elements. The PTC temperature sensor according to the invention is distinguished, in particular, by the fact that, while the manufacturing procedure is cheap, it is not subject to aging due to the effect of varying O.sub.2 partial pressures, has a high resistance to aging of the resistance characteristic in rich and lean gas mixtures, for example in motor vehicle exhaust gases, at 300.degree.-1000.degree. C. and has a construction free from extraneous potential, is characterized by short response times owning to its low heat capacity and is suitable for incorportion in very narrow housing as a consequence of small dimensions.