| 摘要 |
PURPOSE:To reduce limit voltage ratio in a large current region and to improve lightning surge breakdown voltage and stability to surge by forming and calcinating a zinc-oxide based mixed body containing a specified amount of specified addition elements, by applying oxide paste, by carrying out burning to manufacture a baked body which is provided with a side high resistance layer and by applying heat treatment in specified conditions. CONSTITUTION:A mixed body is formed and calcinated to manufacture a sintered body, which mainly contains zinc oxide and contains 0.1 to 2.0 mole % bismuth oxide in terms of Bi2O3, 0.5 to 9 mole % amorphous silica in terms of SiO2, 0.001 to 0.05 mole % aluminum nitrate in conversion of Al2O3, and 0.005 to 0.1mol% bismuth borosilicate glass in terms of B2O3 as addition elements. Oxide paste is applied thereto and baking is carried out to manufacture a baked body which is provided with a side high resistance layer. Heat treatment is applied thereto at a maximum temperature of 520 to 650 deg.C, a heat-up speed of 200 deg.C/hour or more and a heat-down speed of 20 to 150 deg.C/hour to acquire a voltage nonlinear resistor. |
