Claims
- 1. An aluminum nitride sintered body consisting essentially of: aluminum nitride and a sintering aid, wherein the sintered aid is composed of at least one component selected from the group consisting of Yb.sub.2 O.sub.3 and Er.sub.2 O.sub.3, and the sintered body contains up to 0.5% by weight of Yb and/or Er as the metal and has a density of 3.2 to 3.3 g/cm.sup.3 and a heat conductivity of at least 170 W/m.multidot.K.
- 2. An aluminum nitride sintered body as set forth in claim 1, wherein the content of Yb and/or Er as the metal is from 0.01% to 0.2% by weight.
- 3. An aluminum nitride sintered body consisting essentially of: aluminum nitride and a sintering aid, wherein the sintering aid is composed of at least one component selected from the group consisting of Yb.sub.2 O.sub.3 and Er.sub.2 O.sub.3 and a CaO component, and the sintered body contains up to 0.5% by weight of Yb and/or Er as the metal and up to 0.1% by weight of Ca as the metal and has a density of 3.2 to 3.3 g/cm.sup.3 and a heat conductivity of at least 170 W/m.multidot.K.
- 4. An aluminum nitride sintered body as set forth in claim 3, wherein the content of Yb and/or Er as the metal is up to 0.1% by weight and the content of Ca as the metal is up to 0.05% by weight, and the heat conductivity is at least 200 W/m.multidot.K.
- 5. An aluminum nitride sintered body according to claim 1 wherein the sintered body contains from 0.02% to 0.5% by weight of Yb and/or Er as the metal.
- 6. An aluminum nitride sintered body according to claim 1 wherein the sintered body contains from 0.01% to 0.2% by weight of Yb and/or Er as the metal.
- 7. An aluminum nitride sintered body according to claim 1 wherein the sintered body contains from 0.02% to 0.2% by weight of Yb and/or Er as the metal.
- 8. An aluminum nitride sintered body according to claim 3 wherein the sintered body contains from 0.01 to 0.5% by weight of Yb and/or Er as the metal.
- 9. An aluminum nitride sintered body according to claim 3 wherein the sintered body contains from 0.01 to 0.2% by weight of Yb and/or Er as the metal.
- 10. An aluminum nitride sintered body according to claim 3 wherein the sintered body contains from 0.02 to 0.2% by weight of Yb and/or Er as the metal.
- 11. An aluminum nitride sintered body according to claim 3 wherein the sintered body contains from 0.01 to 0.5% by weight of Yb and/or Er as the metal and from 0.01 to 0.1% by weight of Ca as the metal.
- 12. An aluminum nitride sintered body according to claim 3 wherein the sintered body contains from 0.01 to 0.1% by weight of Yb and/or Er as the metal and from 0.0005 to 0.0003% by weight of Ca as the metal.
- 13. An aluminum nitride sintered body according to claim 3 wherein the sintered body contains from 0.01 to 0.04% by weight of Yb and/or Er as the metal, and from 0.001 to 0.003% by weight of Ca as the metal.
- 14. An aluminum nitride sintered body consisting essentially of: aluminum nitride and a sintering aid wherein the sintering aid is composed of a compound of Yb and/or Er capable of being converted to an oxide of Yb and/or Er at the firing temperature, and the sintered body contains from 0.01 to 0.5% by weight of Yb and/or Er as the metal and has a density of 3.2 to 3.3 grams per cubic centimeter and a heat conductivity of at least 170 W/m.multidot.K.
- 15. An aluminum nitride sintered body according to claim 14 wherein the Yb and/or Er compound is selected from the group consisting of ytterbium oxide, ytterbium carbonate, ytterbium nitrate, ytterbium hydroxide, erbium oxide, erbium carbonate, erbium nitrate and erbium hydroxide.
- 16. An aluminum nitride sintered body consisting essentially of: aluminum nitride and a sintering aid wherein the sintering aid is composed of at least one component selected from the group consisting of ytterbium oxide, ytterbium carbonate, ytterbium nitrite, ytterbium hydroxide, erbium oxide, erbium carbonate, erbium nitrate and erbium hydroxide, and a CaO component, and wherein the sintered body contains from 0.01 to 0.5% by weight of ytterbium and/or erbium as the metal, and from 0.0005 to 0.1% by weight of Ca as the metal, and has a density of 3.2 to 3.3 grams per cubic centimeter and a heat conductivity of at least 170 W/m.multidot.K.
- 17. A process for the preparation of an aluminum nitride sintered body, which comprises molding a composition comprising 85 to 97% by weight of an aluminum nitride powder and 3 to 15% by weight of a sintering aid selected from the group consisting of Yb.sub.2 O.sub.3 and Er.sub.2 O.sub.3 and firing the obtained molded body at a temperature of 1600.degree. to 2000.degree. C. in an non-oxidizing atmosphere containing at least 1 Torr of nitrogen gas to thereby evaporate the sintering aid until the content of Yb and/or Er as the metal in the sintered body is up to 0.5% by weight, and wherein at the step of firing the molded body, the average temperature-elevating rate from 1200.degree. C. to the sintering temperature is lower than 40.degree. C./min.
- 18. A process according to claim 17, wherein carbon is incorporated in the non-oxidizing atmosphere and sintering of the molded body is effected in said atmosphere.
- 19. A process according to claim 17, wherein the composition to be molded comprises 90 to 95% by weight of the aluminum nitride powder and 5 to 10% by weight of the sintering aid.
- 20. A process for the preparation of an aluminum nitride sintered body, which comprises molding a composition comprising 85 to 97% by weight of aluminum nitride powder, 3 to 15% by weight of a first sintering aid selected from the group consisting of Yb.sub.2 O.sub.3 and Er.sub.2 O.sub.3 and a second sintering aid comprising 0.01 to 0.2% by weight of a calcium compound capable of being converted to CaO under sintering conditions, firing the obtained molded body in a non-oxidizing atmosphere to thereby evaporate the sintering aids until the content of Yb and/or Er as the metal in the sintered body is up to 0.5% by weight and the content of Ca as the metal is up to 0.1% by weight, and wherein at the step of firing the molded body, the average temperature-elevating rate from 1200.degree. C. to the sintering temperature is lower than 40.degree. C./min.
- 21. A process according to claim 20, wherein carbon is incorporated in the non-oxidizing atmosphere and sintering of the molded body is effected in said atmosphere.
- 22. A process according to claim 20, wherein at the step of firing the molded body, the average temperature-elevating rate from 1200.degree. C. to the sintering temperature is lower than 40.degree. C./min.
- 23. A process for producing an aluminum nitride sintered body, the process including the following steps:
- molding a composition consisting essentially of aluminum nitride powder, and a sintering aid selected from the group consisting of Yb compounds and Er compounds capable of being converted to oxides of such compounds under firing conditions; and
- firing the obtained molded body at a temperature of 1600.degree.-2000.degree. C. in a non-oxidizing atmosphere containing at least one Torr of nitrogen gas to thereby evaporate the sintering aid until the content of Yb and/or Er as the metal in the sintered body ranges from 0.01 to 0.05% by weight as the metal, wherein at the step of firing the molded body, the average temperature-elevating rate from 1200.degree. C. to the sintering temperature is lower than 40.degree. C./min.
- 24. A process according to claim 23 wherein the Yb and Er compounds are selected from the group consisting of ytterbium oxide, ytterbium carbonate, ytterbium nitrate, ytterbium hydroxide, erbium oxide, erbium carbonate, erbium nitrate and erbium hydroxide.
- 25. A process according to claim 24 wherein there is present 85 to 97% by weight of aluminum nitride powder and 3 to 15% by weight of the sintering aid.
- 26. A process according to claim 25 further including from 0.01 to 0.2% by weight of a calcium compound capable of being converted to CaO under sintering conditions.
- 27. An aluminum nitride sintered body produced by the process of claim 17.
- 28. An aluminum nitride sintered body produced by the process of claim 18.
- 29. An aluminum nitride sintered body produced by the process of claim 19.
- 30. An aluminum nitride sintered body produced by the process of claim 20.
- 31. An aluminum nitride sintered body produced by the process of claim 21.
- 32. An aluminum nitride sintered body produced by the process of claim 22.
- 33. An aluminum nitride sintered body produced by the process of claim 23.
- 34. An aluminum nitride sintered body produced by the process of claim 24.
- 35. An aluminum nitride sintered body produced by the process of claim 25.
- 36. An aluminum nitride sintered body produced by the process of claim 26.
Priority Claims (3)
Number |
Date |
Country |
Kind |
1-189133 |
Jul 1988 |
JPX |
|
1-98495 |
Apr 1989 |
JPX |
|
63-98496 |
Apr 1989 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 07/386,789 filed on Jul. 27, 1989, now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (2)
Number |
Date |
Country |
56121978 |
Jul 1984 |
JPX |
2179677 |
Aug 1986 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
386789 |
Jul 1989 |
|