Method for producing a multilayer ceramic component
A multilayer ceramic component includes a stack containing ceramic layers and electrode layers interspersed among the ceramic layers. The electrode layers contain copper and define first and second internal electrodes. First and second external contacts are on different sides of the stack. The first and second external contacts contain copper and are substantially perpendicular to the ceramic layers and electrode layers. The first internal electrode is connected to the first external contact and the second internal electrode is connected to the second external contact. The first and second internal electrodes overlap each other at a plane intersecting the stack. In areas adjacent to boundaries between the first and second external contacts and the ceramic layers, the first and second external contacts are not oxidized and material making-up the ceramic layers is not diminished. A bonding strength of the external contacts to the stack exceeds 50 N.
1. A method for producing a multilayer ceramic component, the multilayer ceramic component comprising a stack comprising ceramic layers and electrode layers interspersed among the ceramic layers, the electrode layers containing copper, the electrode layers comprising first and second internal electrodes, the method comprising:
applying first and second external contacts to different sides of the stack, the first and second external contacts containing copper, the first and second external contacts being substantially perpendicular to the ceramic layers and electrode layers,
wherein applying comprises debindering and sintering metal paste to form the first and second external contacts;
wherein debindering is performed at a temperature of less than or equal to 300° C. in a nitrogen stream with water vapor;
wherein, at least during debindering, an oxygen partial pressure does not drop below a level of p min , at which ceramic contained in the ceramic layers begins to degrade;
wherein the oxygen partial pressure does not exceed a level of p max , at which metallic copper will begin to oxidize;
wherein the first internal electrode is connected to the first external contact and the second internal electrode is connected to the second external contact, the first and second internal electrodes overlapping each other at a plane intersecting the stack,
wherein in areas adjacent to boundaries between the first and second external contacts and the ceramic layers, the first and second external contacts are not oxidized and material comprising the ceramic layers is not diminished, and
wherein a bonding strength of the external contacts to the stack exceeds 50N.
2. The method of claim 1 ,
wherein p min corresponds to an equilibrium point for Cu/Cu 2 O; and
wherein p max corresponds to an equilibrium point for Pb/PbO or Pb/PbTiO 3 .
3. The method of claim 1 , wherein the metal paste contains copper at greater than 70 m % (percentage by mass); and
wherein applying comprises using a glass flow and an organic binder.
4. The method of claim 3 , wherein the organic binder comprises an acrylic resin binder.
5. The method according to claim 3 , wherein the glass flow contains PbO and SiO 2 .
6. The method of claim 3 , wherein applying further comprises firing the metal paste at a temperature between 700 and 860° C.
7. The method of claim 6 , wherein debindering and firing the metal paste are performed using a copper base layer.
8. The method of claim 3 , wherein the metal paste is applied via a screen printing process.