Multilayer component and process for producing a multilayer component
A multilayer component and a mathod for producing a multilayer component are disclosed. In an embodiment a multilayer component includes a ceramic main element and at least one metal structure, wherein the metal structure is cosintered and wherein main element is a varistor ceramic having ≥90 mol % of ZnO, from 0.5 to 5 mol % of Sb 2 O 3 , from 0.05 to 2 mol % of Co 3 O 4 , Mn 2 O 3 , SiO 2 and/or Cr 2 O 3 , and <0.1 mol % of B 2 O 3 , Al 2 O 3 and/or NiO.
1. A multilayer component comprising:
a ceramic main element; and
at least one metal structure, wherein the metal structure is cosintered, and wherein the main element is a varistor ceramic comprising:
≥90 mol % of ZnO,
from 0.5 to 5 mol % of Sb 2 O 3 ,
from 0.05 to 2 mol % of Co 3 O 4 , Mn 2 O 3 , SiO 2 and/or Cr 2 O 3 , and
<0.1 mol % of B 2 O 3 , Al 2 O 3 and/or NiO.
2. The multilayer component according to claim 1 , wherein the main element is doped with a material of the metal structure such that diffusion of the material from the metal structure into the main element during a sintering operation is reduced.
3. The multilayer component according to claim 2 , wherein the main element is doped with from 0.1 to 1 mol per cent of a chemical compound of the material of the metal structure.
4. The multilayer component according to claim 2 , wherein dopants comprise silver oxide or silver carbonate.
5. The multilayer component according to claim 2 , wherein dopants comprise a palladium compound.
6. The multilayer component according to claim 1 , wherein the main element comprises Bi 2 O 3 .
7. The multilayer component according to claim 1 wherein the main element is a ceramic sintered main element with an aid of liquid phases.
8. The multilayer component according to claim 1 , wherein the metal structure comprises at least one internal electrode and/or at least one external metallization and/or at least one via.
9. The multilayer component according to claim 1 , wherein the metal structure is doped with at least one material of the ceramic main element.
10. The multilayer component according to claim 1 , wherein a thickness or lateral extension of the metal structure is less than or equal to 1.5 μm.
11. The multilayer component according to claim 1 , wherein the metal structure comprises silver.
12. The multilayer component according to claim 11 , wherein the metal structure comprises 99% of silver.
13. The multilayer component according to claim 1 , wherein the metal structure comprises palladium.
14. The multilayer component according to claim 1 , further comprising at least one passivating layer, wherein the passivating layer is cosintered, wherein a material of the passivating layer includes glass comprising a filler material or ceramic, and wherein the material of the passivating layer has been applied to the main element before sintering.
15. The multilayer component according to claim 14 , wherein the passivating layer is doped with at least one material of the metal structure and the doping is greater than or equal to a saturation concentration of the material in the passivating layer.
16. A method for producing the multilayer component according to claim 1 , the method comprising:
arranging layers comprising a ceramic composition and layers comprising an electrode paste alternately on top of one another to form a stack of layers; and
sintering the stack of layers to form ceramic layers with internal electrodes arranged in between.
17. The method according to claim 16 , wherein the ceramic composition is doped with from 0.1 to 1 mol per cent of at least one material of the electrode paste.
18. The method according to claim 16 , further comprising:
applying an insulating layer on at least one upper side of the ceramic composition, wherein the insulating layer is doped with at least one material of the electrode paste and at least one material of the ceramic composition, wherein the insulating layer is applied before sintering.
19. The method according to claim 18 , wherein the electrode paste comprises silver, wherein the electrode paste is doped with at least one material of the ceramic composition, and wherein the ceramic composition is doped with silver oxide or silver carbonate.