Zinc oxide voltage-nonlinear resistor
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMasahiro Nagasawa, Yasuo Wakahata, Kensuke Kuchiba, Kunio Nishi, Hiroshi Abe
Life of this patent
Estimating the term…
Abstract
A voltage-dependent resistor (varistor) of the bulk type comprising a sintered body consisting essentially of, as a main constituent, ZnO and additives of various metal oxides and further containing an additive of at least one of Al.sub.2 O.sub.3, In.sub.2 O.sub.3 Ga.sub.2 O.sub.3 provide much improved characteristics, especially superior limiting voltage ratio, surge resistance and life of the varistor.
Claims5
A voltage-dependent resistor of bulk type comprising a sintered body consisting essentially of a voltage-dependent composition which comprises, as a main constituent, zinc oxide (ZnO) and, as an additive, at least one member selected from the group consisting of bismuth oxide (Bi.sub.2 O.sub.3), barium oxide (BaO), strontium oxide (SrO), lead oxide (PbO) and uranium oxide (UO.sub.2), and, as a further additive, at least one member selected from the group consisting of aluminum oxide (Al.sub.2 O.sub.3), indium oxide (In.sub.2 O.sub.3) and gallium oxide (Ga.sub.2 O.sub.3) in an amount of 1 .times. 10.sup..sup.-4 to 5 .times. 10.sup..sup.-3 mole per 100 moles of ZnO, and electrodes applied to opposite surfaces of said sintered body.
Dependencies are inferred from the claim text.