Non-linear resistor and method of manufacturing the same

Patent 4606116 Issued on August 19, 1986. Estimated Expiration Date:

July 11, 2005. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Fine-grain semiconducting ceramic compositions
Patent #: 4347167
Issued on: 08/31/1982
Inventor: Payne , et al.

Dielectric ceramic materials with insulated boundaries between crystal grains, and process for preparation
Patent #: 4405477
Issued on: 09/20/1983
Inventor: Murase , et al.

Low voltage ceramic varistor
Patent #: 4436650
Issued on: 03/13/1984
Inventor: Bowen

Semiconductive ceramic materials with a voltage-dependent nonlinear resistance, and process for preparation Patent #: 4438214
Issued on: 03/20/1984
Inventor: Masuyama , et al.

Inventors

Application

No. 06/753836 filed on 07/11/1985

US Classes:

29/610.1, Resistor making252/519.12, Titanium containing29/612Thermally variable

Examiners

Primary: Barr, Josephine

Attorney, Agent or Firm

Spain; Norman N.

International Classes

H01C 7/105 (20060101)
H01C 7/115 (20060101)

Foreign Application Priority Data

1981-05-29 DE

Abstract

A non-linear resistor having an operational field strength which optionally is formed as a VDR- or as an NTC-resistor having a ceramic sintered body on the basis of a polycrystalline alkaline earth metal titanate doped with a small quantity of a metal oxide so as to produce an N-type conductivity, in which the sintered body comprises at its grain boundaries insulating layers formed by re-oxidation of the sintered body and consists of an alkaline earth metal titanate having a Perowskite structure of the general formulawherein: A=alkaline earth metal; Ln=rare earth metal; Me=metal having a valency of 5 or more; 0.0005<x<solubility limit in the Perowskite phase; y=0.001 to 0.02. The sintered body becomes adjustable in its non-linear resistance variation by selection of the re-oxidation temperature and of the re-oxidation duration in such manner that an initially present NTC-characteristic gradually is observable only at ever increasing temperatures and changes into a VDR-characteristic in the range of the operating temperature of the resistor. FIG. 1.