| 摘要 |
<p>PURPOSE:To get a highly reliable zinc oxide varistor by baking, under a speci fied temperature condition, a crystallized glass paste of PbO-ZnO-B2O3-SiO2-Li2O containing each component by specified wt%, on the sides of a sintered body containing ZnO as its main ingredient. CONSTITUTION:A sintered body 1, which has ZnO as its main ingredient, is made. Next, crystallized glass paste comprising 55.0-75.0wt% PbO, 10.0-30.0wt% ZnO, 5.0-15.0wt% B2O3, 0-15.0wt% SiO2, and 0.1-5.0wt% Li2O is applied by 10.0-150.0mg/cm<2>. And a baking treatment is applied in a temperature range of 450-600 deg.C. This way, high resistance layers 3 are made on the sides. What is more, the linear expansion coefficient of the crystallized glass is 65-90X10<-7>/ deg.C. Hereby, the strength and the adhesion of the cover improve, and a zinc oxide varistor also excellent in life property can be obtained.</p> |
