Non-linear electrical resistor having varistor characteristics
AssigneeMurata Manufacturing Co., Ltd.
InventorsHaruhumi Mandai, Kazutaka Nakamura, Yasuyuki Naito, Kiyoshi Iwai
Life of this patent
Estimating the term…
Abstract
A ceramic composition for use in production of non-linear resistors. This composition comprises strontium titanate (or a mixture containing strontium titanate as a major ingredient) and 0.1 to 1.0 mol % of Er.sub.2 O.sub.3, Ho.sub.2 O.sub.3 or mixtures thereof. In a preferred composition 0.02 to 0.2 mol % of at least one of MnO.sub.2, Co.sub.2 O.sub.3 or mixtures thereof are included. Non-linear resistors produced using the composition are comparable to those produced from conventional ceramic compositions in the threshold level voltage and non-linear factor but have greatly improved flexural strength.
Claims13
A non-linear electrical resistor consisting essentially of strontium titanate and 0.1 to 1.0 mol % of Er.sub.2 O.sub.3, Ho.sub.2 O.sub.3 or mixtures thereof, said non-linear electrical resistor having varistor characteristics and having a granular crystalline structure wherein the grains of said structure are semiconductors and the grain boundaries of said structure have a higher electrical resistance than said grains.
A ceramic non-linear resistor consisting essentially of strontium titanate, 0.1 to 1.0 mol % of Er.sub.2 O.sub.3, Ho.sub.2 O.sub.3 or mixtures thereof and 0.02 to 0.2 mol % of MnO.sub.2, Co.sub.2 O.sub.3 or mixtures thereof, said ceramic non-linear resistor having varistor characteristics and having a granular crystalline structure wherein the grains of said structure are semiconductors and the grain boundaries of said structure have a higher electrical resistance than said grains.
A ceramic material consisting essentially of strontium titanate with minor amounts of ErO.sub.3, Ho.sub.2 O.sub.3 or mixtures thereof, said material having a granular crystalline structure wherein the grains in said structure are a semiconductor material consisting essentially of strontium titanate and the grain boundaries of said structure have a higher electrical resistance than said grains.
Dependencies are inferred from the claim text.