| 摘要 |
PROBLEM TO BE SOLVED: To provide a zinc oxide varistor, which is superior in discharge breakdown current characteristics and moreover, inhibits the reduction in voltage nonlinearity at the time of a baking treatment to the minimum, by a method wherein side surface high-resistance layers consisting of a crystalline glass layer, which contains PbO containing at least a specified wt.% of ZrO2 as its main component, are respectively provided on the side surfaces of a sintered body containing zinc oxide as its main component. SOLUTION: Side surface high-resistance layers 3 consisting of a crystalline glass layer, which contains PbO containing at least 0.1 to 5.0wt.% of a zirconium oxide calculated in terms of the form of ZnO2 as its main component, are respectively formed on the side surfaces of a sintered body 1, which contains zinc oxide as its main component and has varistor characteristics in the sintered body itself. The layers 3 are constituted of a PbO-ZnO-B2 O3 -SiO2 -ZnO2 crystalline glass layer or a PbO-ZnO-B2 O3 -SiO2 -ZnO2 crystalline glass layer. The linear expansion coefficient of the crystalline glass layer is set to 65 to 90×10<-7> 1 deg.C. |
