Multilayer varistor
AssigneeTDK Corporation
InventorsTomohiro Arashi, Yukie Nakano, Atsushi Hitomi, Akira Sato, Takeshi Nomura
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Abstract
A multilayer varistor comprising a varistor chip body having alternately stacked ceramic layers and internal electrode layers is provided. The ceramic layer is composed of a composite oxide containing Ti and/or Zr and Ba as a main component and Si and/or Al as a subordinate component, substantially free of Cr, and has a perovskite phase. The internal electrode layer is composed of a conductor containing a base metal such as Ni or Ni alloy as a main component. The varistor is used in an electric circuit for suppressing noise.
Claims15
A multilayer varistor for use in an electric circuit for suppressing noise, comprising a varistor chip body having alternately stacked ceramic layers and internal electrode layers,
- said ceramic layers consisting essentially of a composite oxide as a main component and at least one of SiO.sub.2 and Al.sub.2 O.sub.3 as a subordinate component, being substantially free of chromium, and wherein MgO is present in an amount of from 0.001 to 5 wt %, and having a perovskite phase,
- said internal electrode layers comprising a conductor which is nickel or a nickel alloy, wherein the composite oxide is of the formula:
- (Ba.sub.1-x-y Ca.sub.x Sr.sub.y).sub.m (Ti.sub.1-z Zr.sub.z)O.sub.3
- wherein letters x, y, z, and m representative of a molar ratio are in the range:
- 0<x<0.1, 0<y<0.1, 0<x+y<0.1, 0.ltoreq.z.ltoreq.0.3 and 0.9.ltoreq.m.ltoreq.1.2, and wherein the sum of SiO.sub.2 and Al.sub.2 O.sub.3 is at least 1% by weight of the composite oxide as the main component.
Dependencies are inferred from the claim text.