Method of stabilizing the hot resistance of ceramic positive temperature coefficient resistors
AssigneeSiemens Aktiengesellschaft
InventorBaerbel Seebacher
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Abstract
The hot resistance of ceramic positive temperature coefficient resistors is stabilized by subjecting such resistors to a heat treatment over a period of time ranging from 1 to 40 hours at a temperature in the range of 400.degree. to 500.degree. C., either during or after the application of contact coatings on the resistor.
Claims3
A method of stabilizing the hot resistance of a ceramic positive temperature coefficient resistor consisting of a barium titanate based ferroelectric material having a Perowskite structure which is doped so as to render in semiconductive, said resistor being provided with non-blocking contact coatings comprised predominantly of silver applied on a thin film of an indium material selected from the group consisting of indium and indium-gallium comprising:
- subjecting said positive temperature coefficient resistor to a heat-treatment over a period of time ranging from 1 to 40 hours at a temperature in the range of 400.degree. to 500.degree. C., said heat-treatment occurring at least after the application of said non-blocking contact coatings.
Dependencies are inferred from the claim text.