PROCESS FOR PRODUCING ZINC OXIDE VARISTOR HAVING HIGH POTENTIAL GRADIENT AND HIGH NON-LINEARITY COEFFICIENT

摘要

PURPOSE: A process for producing a zinc oxide varistor having a high potential gradient and a non-linearity coefficient are provided to have ZnO varistor be excellent in material composition uniformity and structural uniformity. CONSTITUTION: A process for producing a zinc oxide varistor suited for use in producing a specific zinc oxide varistor, a specific non-linearity coefficient, and a specific leak current comprises the steps of: individually advanced preparation of zinc oxide grains doped with non-equivalent ions; individually advanced preparation of sintered powders according to the preset potential gradient of the specific zinc oxide varistor; mixing the zinc oxide grains doped with non-equivalent ions and the sintered powders in a specific ratio to produce a ceramic powder; and producing a disc-shaped or multiplayer zinc oxide varistor made from the ceramic powder. The sintered powders are prepared by mixing (a) starting material(s); sintering the mixture into sintered powders; and grinding the sintered powders to a desired fineness. [Reference numerals] (AA) ZnO* grains of specimen 8