Abstract: Electrical devices, particularly circuit protection devices, contain conductive polymer elements whose edges are formed by breaking the conductive polymer element, along a desired path, without the introduction of any solid body into the element. The resulting cohesive failure of the conductive polymer produces a distinctive fractured surface. One method of preparing such devices involves etching fracture channels in the electrodes of a plaque containing a PTC conductive polymer element sandwiched between metal foil electrodes, and then snapping the plaque along the fracture channels to form individual devices.
Type:
Grant
Filed:
February 28, 1997
Date of Patent:
January 26, 1999
Assignee:
Raychem Corporation
Inventors:
Michael Zhang, Mark S. Thompson, James Toth, William Cardwell Beadling