PRODUCTION OF VOLTAGE NONLINEAR RESISTOR

摘要

PURPOSE:To enhance uniformity of voltage distribution in the direction of main surface by placing powder in a firing sheath box and firing a mold while embedding in the powder thereby making temperature distribution uniform in a furnace. CONSTITUTION:ZnO powder and an oxide of rare earth element are molded 1 while granular powder of same composition is prepared and employed in the firing of the mold 1. The molds 1 are stacked in a firing sheath box 2 and the granular powder 6 is filled therein. The molds 1 are then fired while being embedded in the powder 6 thus obtaining many sintered bodies simultaneously. This method eliminates uneven temperature distribution in the furnace, enhances uniformity of voltage distribution in the direction of main surface and thereby eliminates local concentration of current to enhance surge resistance. Furthermore, contamination due to diffusion can be prevented during firing process because the granular powder has the same composition as the voltage nonlinear resistor.