Provided according to embodiments of the invention are varistor ceramic formulations that include zinc oxide (ZnO). In particular, varistor ceramic formulations of the invention may include dopants including an alkali metal compound, an alkaline earth compound, an oxide of boron, an oxide of aluminum, or a combination thereof. Varistor ceramic formulations may also include other metal oxides. Also provided according to embodiments of the invention are varistor ceramic materials formed by sintering a varistor ceramic formulation according to an embodiment of the invention. Further provided are varistors formed from such ceramic materials and methods of making such materials.

A thermally protected metal oxide varistor includes a body, a first electrode, a thermal fuse, and a glue. The body is made up of a crystalline microstructure including zinc oxide mixed with one or more other metal oxides. The first electrode is located on one side of the body and is connected to a first lead wire. The thermal fuse is connected between the first electrode and the first lead wire. The glue is to be deposited over the thermal fuse as well as over a top portion of the first lead wire.

A thermally protected metal oxide varistor includes a body, a first electrode, a thermal fuse, and a glue. The body is made up of a crystalline microstructure including zinc oxide mixed with one or more other metal oxides. The first electrode is located on one side of the body and is connected to a first lead wire. The thermal fuse is connected between the first electrode and the first lead wire. The glue is to be deposited over the thermal fuse as well as over a top portion of the first lead wire.

An electrical component for embedding into a carrier comprises a ceramic main body, an electrically insulating passivation layer which is applied to the main body, and at least one inner electrode. In addition, the electrical component comprises an outer electrode which is connected to the inner electrode, wherein the outer electrode comprises a first electrode layer comprising a metal and a second electrode layer which is arranged on the latter and comprises copper.

A voltage-nonlinear resistor element 10 includes a voltage-nonlinear resistor (referred simply as “resistor”) 20 and a pair of electrodes 14 and 16 between which the resistor 20 is interposed. The resistor 20 has a multilayer structure including a first layer 21 composed primarily of zinc oxide, a second layer 22 composed primarily of zinc oxide, and a third layer 23 composed primarily of a metal oxide other than zinc oxide. The second layer 22 is adjacent to the first layer 21 and has a smaller thickness and a higher volume resistivity than the first layer 21. The third layer 23 is adjacent to the second layer 22.

To provide a zinc oxide-based varistor that exhibits adequate characteristics without using antimony. Disclosed is a sintered body for a varistor, including zinc oxide as a main component; 0.6 to 3.0 mol % of bismuth oxide in terms of bismuth (Bi); 0.2 to 1.4 mol % of cobalt oxide in terms of cobalt (Co); 0.1 to 1.5 mol % of chrome oxide in terms of chrome (Cr); and 0.1 to 1.5 mol % of manganese oxide in terms of manganese (Mn), wherein the contents of antimony (Sb), a rare earth element and tin (Sn) are not more than a level of impurities.

To provide a zinc oxide-based varistor that exhibits adequate characteristics without using antimony. Disclosed is a sintered body for a varistor, including zinc oxide as a main component; 0.6 to 3.0 mol % of bismuth oxide in terms of bismuth (Bi); 0.2 to 1.4 mol % of cobalt oxide in terms of cobalt (Co); 0.1 to 1.5 mol % of chrome oxide in terms of chrome (Cr); and 0.1 to 1.5 mol % of manganese oxide in terms of manganese (Mn), wherein the contents of antimony (Sb), a rare earth element and tin (Sn) are not more than a level of impurities.

In one embodiment a varistor may include a ceramic body. The varistor may further comprise a multilayer coating disposed around the ceramic body. The multilayer coating may include a first layer comprising a phenolic material or a silicone material; and a second layer adjacent the first layer, the second layer comprising a high dielectric strength coating.

In one embodiment a varistor may include a ceramic body. The varistor may further comprise a multilayer coating disposed around the ceramic body. The multilayer coating may include a first layer comprising a phenolic material or a silicone material; and a second layer adjacent the first layer, the second layer comprising a high dielectric strength coating.

A laminated varistor includes a varistor layer, a first internal electrode provided on an upper surface of the varistor layer, a second internal electrode provided on a lower surface of the varistor layer and facing the first internal electrode across the varistor layer in upward and downward directions, a first external electrode provided on a first side surface of the varistor layer and electrically connected to the first internal electrode, and a second external electrode provided on a second side surface of the varistor layer and electrically connected to the second internal electrode. The first internal electrode is extended from the first external electrode in a first extension direction. The first internal electrode includes first electrode strips arranged in a first arrangement direction perpendicular to the first extension direction and spaced apart from one another. This laminated varistor has improved surge-resistant characteristics.