| 摘要 |
PROBLEM TO BE SOLVED: To obtain a zinc oxide-base ceramic capable of forming a zinc oxide varistor for low and high-temp. use excellent in electrical characteristic and reliability on the DC load and surge by low-temp. sintering in high yield. SOLUTION: The mixed powder of bismuth oxide, titanium oxide, antimony oxide, chromium oxide and boron oxide is heat-treated at 500 deg.C for 1hr and pulverized. The obtained powder is mixed with zinc oxide powder, cobalt oxide powder and manganese dioxide powder and crushed. The mixed powder is compacted into a disk, and the green compact is kept at 950 deg.C for 2hr to obtain a sintered compact 11. An aluminum layer is formed on both sides of the sintered compact 11, copper is thermally sprayed thereon to form an electrode 12, a lead wire 13 is attached to the electrode, and the sintered compact except the lead wire is coated with a resin to obtain a zinc oxide varistor. |
