METHOD FOR MANUFACTURING VARISTOR

摘要

A method for manufacturing varistor by which a varistor having a high plating resistance and a high moisture resistance is manufactured by selectively forming a compact high-resistance layer having a uniform thickness on the surface of a varistor element. In the method, the varistor element (1) is first formed by alternately laminating ceramic sheets (1a) mainly of a zinc oxide and internal electrodes (2) upon one another, and then, Ag electrode paste which becomes external electrodes (3) is applied to both end faces of the element (1). Then, after the element (1) is sintered through heat treatment, the element (1) is buried in SiO2 or a mixture (5) containing SiO2 and the element (1) is heat-treated for 5-10 minutes at 600-950° C. in the air or in an oxygen atmosphere.