Tdk Electronics Company, Limited

Ryoichi Shioi

Kazumasa Umeya

Hisao Senzaki

Kazunari Yonezuka

Tamotu Yamauchi

Hisao Nakagawa

Shoji Koyama

Hideshi Kataoka

A PTC heating element with a honeycomb ceramic body comprising a barium titanate and semiconductor element, which provides the ceramic body with a positive temperature coefficient of resistance over the Curie point. An electrode is deposited on each end of the honeycomb body. The electrodes according to the present invention have a non-ohmic property, while the conventional electrodes have been ohmic. A high rush current and migration are advantageously decreased by the non-ohmic electrodes.

PTC heating apparatus

Disclosed herein is a heating element for an air heater and the like comprising a ceramic material in the form of a honeycomb as well as the process for producing the ceramic material. The heating element is characterized by its relatively high amount of heat generation capability compared to a conventional heating element of the same size. Preferable ceramic materials for the heating element have a temperature coefficient of electrical resistance of from 5 to 20%/.degree.C., and consist essentially of from 38.7 to 47.3 molar % of BaO, from 2.5 to 11 molar % of PbO, from 49.8 to 50% of TiO.sub.2, from 0.05 to 0.3 molar % of a semiconductor forming element and from 0.002 to 0.015 part by weight of Mn.

Heating element made of PTC ceramic material

In a honeycomb heating element comprising a PTC thermister body, a single electrode layer composed of a silver paste was conventionally used for applying power to the body. In the present invention, two or three electrode layers with improved electrical and chemical properties are used to provide the heating element with a long service life, improved reliability and a high heat generation.

PTC Honeycomb heating element with multiple electrode layers

Growing community of inventors

Nikahomachi, Japan

Ryoichi Shioi