Metal oxide varistor made by a co-precipation process and freeze-dried

摘要

A metal oxide varistor is disclosed which a component of grain bodies comprised of zinc oxide and a component of grain boundary layers comprised of another metallic oxide, containing metal other than zinc wherein at least a portion of these starting materials comprised a fine particle powder prepared by a co-precipitatin method. The metal oxide varistor of the present invention is excellent in varistor characteristics such as non-linearity to voltage, life performances and capability of energy dissipation, is small in a scatter of the above characteristics between manufacture lots or within each lot at the time of manufacture, and has a good quality stability. Unexpected results are obtained when the co-precipitated fine particles are subjected to a refrigeration-dehydration type process.