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, 1999
Filed:
Dec. 11, 1996
Murata Manufacturing Co., Ltd., Kyoto-fu, JP;
Abstract
A positive characteristic thermistor device includes a device main body made of a semiconductor ceramic material which reliably and cleanly delaminates upon the application of excessive voltage thereto. The main body has outer layers having lower porosity formed on both sides of an inner layer having higher porosity. The inner layer having higher porosity can be obtained by burning a ceramic material for positive characteristic thermistors including resin beads mixed therein. After forming the main body, an electrode is formed on the outer surface of each of the outer layers. When an overvoltage is applied to this positive characteristic thermistor device, delamination occurs in the inner layer having higher porosity to create an open-circuit in a circuit in which the thermistor device is connected.