Processing method for constraining lower melting point metals within ceramic laminates during sintering
View Patent ↗A method is described. The method is a method for making a constraining ceramic assembly. The method includes applying at least one metallic electrode to a substrate. The method also includes applying a porous ceramic layer to the substrate to cover the metallic electrode. The method also includes sintering the substrate, the porous ceramic layer, and the metallic electrode together at a sintering temperature above a melting point of the metallic electrode.
1. A method of making a constraining ceramic assembly, the method comprising:
forming a cavity in a substrate to facilitate flow of at least one metallic electrode during a sintering process;
applying the at least one metallic electrode to the substrate;
applying a porous ceramic layer to the substrate to cover the at least one metallic electrode; and
sintering the substrate, the porous ceramic layer, and the at least one metallic electrode together at a sintering temperature above a melting point of the metallic electrode.
2. The method of claim 1 , further comprising placing a fugitive material into the cavity, wherein the fugitive material is expended during sintering.
3. The method of claim 1 , wherein the cavity is formed to allow the flow of the at least one metallic electrode to form an electrical via.
4. The method of claim 1 , wherein the cavity is formed to allow the flow of the at least one metallic electrode to form a contact pad.
5. The method of claim 1 , wherein the porous ceramic layer has a porosity up to approximately 25%.
6. The method of claim 1 , wherein the sintering temperature is between 1000° C. and 1700° C.
7. An apparatus comprising:
a substrate;
a porous ceramic layer; and
a metallic electrode disposed between the substrate and the porous ceramic layer, wherein the metallic electrode is enclosed by the substrate and the porous ceramic layer; and wherein the substrate and the porous ceramic layer are sintered together with the metallic electrode enclosed, wherein the metallic electrode has a melting point lower than a sintering temperature of the substrate or the porous ceramic layer, wherein the apparatus further comprises a cavity to facilitate flow of the metallic electrode during sintering.
8. The apparatus of claim 7 , wherein the substrate comprises a porous ceramic.
9. The apparatus of claim 7 , wherein the metallic electrode comprises a metal having a melting point below a sintering temperature of the substrate and the porous ceramic layer.
10. The apparatus of claim 9 , wherein the metallic electrode comprises gold.
11. The apparatus of claim 7 , wherein at least one of the substrate and the porous ceramic layer comprises stabilized zirconia.
12. The apparatus of claim 7 , wherein the electrode comprises a metallic ribbon.
13. A system comprising:
a sensor disposed in a gas environment, wherein the sensor is configured to detect a concentration within the gas environment, the sensor comprising:
a substrate;
a porous ceramic layer; and
a metallic electrode disposed between the substrate and the porous ceramic layer, wherein the metallic electrode is enclosed by the substrate and the porous ceramic layer; and wherein the substrate and the porous ceramic layer are sintered together with the metallic electrode enclosed, wherein the metallic electrode has a melting point lower than a sintering temperature of the substrate and the porous ceramic layer, wherein the sensor further comprises a cavity to facilitate flow of the metallic electrode during sintering.
14. The system of claim 13 , wherein the substrate comprises a porous ceramic.
15. The system of claim 13 , wherein the electrode comprises gold.
16. The system of claim 13 , wherein the sensor has a planar geometry.
17. The system of claim 13 , wherein the sensor has a non-planar geometry.
18. The system of claim 13 , further comprising a heater to apply heat to the sensor.