| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable a ZnO element to be improved in withstand voltage characteristics by the use of a lead-free glass insulating material whose main components are Bi<SB>2</SB>O<SB>3</SB>and B<SB>2</SB>O<SB>3</SB>, and to enable the ZnO element to have an improved discharge withstand current rating to excessive lightning impulses and switching impulses. <P>SOLUTION: Additive metal oxide powder and pure water are mixed together in a wet manner and ground into an additive slurry (ST1); the additive slurry, ZnO, and an organic binder solution are mixed together into a material slurry (ST2); the material slurry is deaerated and spray-dried into granulated powder (ST3); the granulated powder is molded into a disk or the like by a molding press (ST4); the molded disk is calcinated into a calcinated body (ST5); ceramic insulating material is applied on the sides of the calcinated body (ST6); the calcinated body where the ceramic insulating material has been applied is burned into a sintered body (ST7); a lead-free glass material whose main components are Bi<SB>2</SB>O<SB>3</SB>and B<SB>2</SB>O<SB>3</SB>is applied on the sides of the sintered body (ST8); the sintered body is baked (ST9); both the end faces of the baked body are polished (ST10); and an aluminum electrode is provided to each end face of the baked body by thermal spraying for the formation of the ZnO element (ST11). <P>COPYRIGHT: (C)2004,JPO |
