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:
May. 15, 1997
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A thermistor element with positive temperature characteristic (PTC) has a planar ceramic member with a positive temperature characteristic of which the thickness is greater at its peripheral part than at the center part, decreasing either gradually or in a stepwise manner. Protrusions may be formed along its periphery. A PTC thermistor is formed with electrodes formed on both main surfaces of such a PTC thermistor, each electrode having a lower-layer electrode all over a main surface and an upper-layer electrode on the lower-layer electrode. The upper-layer electrode has a smaller surface area than the lower-layer electrode such that a portion of the lower-surface electrode is exposed at the periphery. The upper-layer electrodes may be formed at the center parts of the main surfaces, exclusive of the peripheral parts or where the protrusions are formed. The lower-layer electrodes may be mostly of Ni and the upper-layer electrodes mainly of Ag.