Effects of Annealing on Dielectric Loss and Microstructure of Aluminum Nitride Ceramics
The effect of annealing on tan and microstructures of aluminum nitride (AlN) ceramics were explored. Yttria was added as a sintering additive to AlN powders, and the powders were pressureless-sintered at 1900°C for 2 h in a nitrogen flow atmosphere. In succession to sintering, AlN samples were annealed at 720, 970 and 1210°C for 2 and 4 h. Very low tan values between 2.6 and 6.0 × 10−4 at 28 GHz were obtained when the AlN samples were annealed for 4 h at all the annealing temperatures.
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Document Type: Research Article
Affiliations: National Institute of Advanced Industrial Science and Technology (AIST) 2266-98 Anagahora, Moriyama-ku, Nagoya 463-8560, Japan
Publication date: November 1, 2005