Varistor ceramic, multilayer component comprising the varistor ceramic, and production method for the varistor ceramic
A varistor ceramic includes the following materials: Zn as the main component, Pr in a proportion of 0.1 to 3 atom %, and a metal M selected from Y, Ho, Er, Yb and Lu in a proportion of 0.1 to 5 atom %.
1. A varistor ceramic comprising:
Zn as the main component,
Pr in a proportion of 0.1 to 3 atom %, based on the atom % of the ceramic varistor,
at least one selected from the group consisting of Ca in a proportion of 0.001 to 5 atom %, based on the atom % of the ceramic varistor, Si in a proportion of 0.001 to 0.5 atom %, based on the atom % of the ceramic varistor, B in a proportion of 0.001 to 5 atom %, based on the atom % of the ceramic varistor, and
at least one metal M selected from the group consisting of Y, Ho, Er, Yb and Lu in a proportion of 0.1 to 5 atom %.
2. The varistor ceramic according to claim 1 , wherein M is Y or Lu.
3. The varistor ceramic according to claim 1 further comprising Co in a proportion of 0.1 to 10 atom %, based on the atom % of the ceramic varistor.
4. The varistor ceramic according to claim 1 , further comprising Al in a proportion of 0.001 to 0.01 atom %, based on the atom % of the ceramic varistor.
5. The varistor ceramic according to claim 1 , further comprising Cr in a proportion of 0.001 to 5 atom %, based on the atom % of the ceramic varistor.
6. The varistor ceramic according to claim 1 , further comprising:
Co in a proportion of 0.1 to 10 atom %,
Ca in a proportion of 0.001 to 5 atom %,
Si in a proportion of 0.001 to 0.5 atom %,
Al in a proportion of 0.001 to 0.1 atom %,
Cr in a proportion of 0.001 to 5 atom %,
B in a proportion of 0.001 to 5 atom, all based on the atom % of the ceramic varistor.
7. The varistor ceramic according to claim 1 , having a relative permittivity ∈ r of less than 2000.
8. The varistor ceramic according to claim 1 , wherein relative permittivity of the varistor material is reduced by adding M.
9. The varistor ceramic according to claim 1 , having a sintering temperature between 1000 and 1300° C.
10. The varistor ceramic according to claim 1 , containing substantially no alkali metals.
11. A multilayer component comprising a varistor ceramic according to claim 1 , configured for an ESD protection.
12. A method for producing a varistor ceramic according to claim 1 , comprising:
a) calcining a raw ceramic material,
b) producing a slurry containing the raw ceramic material,
c) preparing green foils from the slurry,
d) debinding the green foils,
e) sintering debound green foils.