Multilayer positive temperature coefficient device and method of making the same

Abstract

An improved PTC device and method of manufacturing is disclosed. In one embodiment, the device and method incorporates an improved metal-ceramic composite PTC material manufactured by: (a) heating a ceramic material to a sufficiently high temperature to induce the ceramic material's PTC properties; (b) grinding the ceramic PTC material into a powder; (c) mixing the ceramic PTC material powder with a metal material powder so as to produce a metal-ceramic composite material powder; and (d) sintering the composite material powder at a temperature between 600° and 950° C. In alternative embodiments, an improved multi-layer structure and method of manufacturing such a structure is disclosed. In various embodiments, a PTC device made in accordance with the improved multi-layer structure and method of manufacture may or may not incorporate the improved metal-ceramic composite PTC material disclosed herein, but may use conventional ceramic-based PTC materials.