Method of forming a high thermal conductivity composite dielectric material
Disclosed herein are embodiments of materials having high thermal conductivity along with a high dielectric constants. In some embodiments, a two phase composite ceramic material can be formed having a contiguous aluminum oxide phase with a secondary phase embedded within the continuous phase. Example secondary phases include calcium titanate, strontium titanate, or titanium dioxide.
1. A method of forming a composite ceramic material, the method comprising:
mixing together materials that will form out a primary phase of aluminum oxide, a first secondary phase of CaTiO 3 located within the primary phase, and a second secondary phase of LaAlO 3 located within the primary phase, the materials forming the primary phase being generally non-reactive with materials forming the first and second secondary phases; and
sintering the materials to form a composite ceramic having the primary phase and the first and second secondary phases, the composite ceramic having a dielectric constant of greater than 20 and a thermal conductivity of greater than 20 W·m −1 ·K −1 .
2. The method of claim 1 wherein the composite ceramic has a thermal conductivity of greater than 30 W·m −1 ·K −1 .
3. The method of claim 1 wherein the primary phase is generally contiguous.
4. The method of claim 1 wherein the composite ceramic has a dielectric constant of greater than 25.
5. The method of claim 1 wherein the composite ceramic has a dielectric constant of greater than 35.
6. The method of claim 1 wherein the composite ceramic has a temperature drift of resonant frequency lower than 1000 ppm/Degree C.
7. The method of claim 1 further comprising machining the composite ceramic.
8. The method of claim 7 further comprising forming a radiofrequency component from the composite ceramic.
9. A method of forming a composite ceramic material, the method comprising:
mixing together materials that will form out a primary phase of aluminum oxide, a first secondary phase of CaTiO 3 located within the primary phase, and a second secondary phase of La 2 MgTiO 6 located within the primary phase, the materials forming the primary phase being generally non-reactive with materials forming the first and second secondary phases; and
sintering the materials to form a composite ceramic having the primary phase and the first and second secondary phases, the composite ceramic having a dielectric constant of greater than 20 and a thermal conductivity of greater than 20 W·m −1 ·K −1 .
10. The method of claim 9 wherein the composite ceramic has a thermal conductivity of greater than 30 W·m −1 ·K −1 .
11. The method of claim 9 wherein the primary phase is generally contiguous.
12. The method of claim 9 wherein the composite ceramic has a dielectric constant of greater than 25.
13. The method of claim 9 wherein the composite ceramic has a dielectric constant of greater than 35.
14. The method of claim 9 wherein the composite ceramic has a temperature drift of resonant frequency lower than 1000 ppm/Degree C.
15. A method of forming a composite ceramic material, the method comprising:
mixing together materials that will form out a primary phase of aluminum oxide, and a plurality of secondary phases, a first of the plurality of secondary phases being CaTiO 3 and a second of the plurality of secondary phases being selected from the group consisting of LaAlO 3 , La 2 MgTiO 6 , YAlO 3 , SmAlO 3 , Mg 4 Nb 2 O 9 , and La 4 Ti 3 O 12 ; and
sintering the materials to form a composite ceramic having the primary phase and the plurality of secondary phases, the composite ceramic having a dielectric constant of greater than 20.
16. The method of claim 15 wherein the composite ceramic has a thermal conductivity of greater than 20 W·m −1 ·K −1 .
17. The method of claim 15 wherein the composite ceramic has a thermal conductivity of greater than 30 W·m −1 ·K −1 .
18. The method of claim 15 wherein the composite ceramic has a dielectric constant of greater than 25.
19. The method of claim 15 wherein the composite ceramic has a dielectric constant of greater than 35.
20. The method of claim 15 wherein the composite ceramic has a temperature drift of resonant frequency lower than 1000 ppm/Degree C.