Optimization of Aluminum Nitride Thermal Conduchvity VIA Controlled Powder Processing

Autor: Kris K. Killinger, Theresa A. Guiton, James E. Volmering
Rok vydání: 1992
Předmět:
Zdroj: MRS Proceedings. 271
ISSN: 1946-4274
0272-9172
DOI: 10.1557/proc-271-851
Popis: The emergence of aluminum nitride ceramics in electronic and structural applications has been largely due to the increased availability of high quality powders. Much of the process development has been concentrated in capturing markets within the electronics industry, mainly high thermal conductivity substrates. The thermal conductivity of A1N substrates is strongly dependent on oxygen chemistry and sintering parameters. A key source of oxygen is AlN powder impurities. In this study, powders with differing oxygen contents were formulated with various Y2O3 levels. The results indicate that the distribution of sintered oxygen is strongly correlated with the relative concentration of the powder's lattice and surface oxygen. Under the sintering parameters of the analysis, optimal thermal conductivities were achieved when Y4Al2O9 was present as the grain boundary phase. As predicted, the powders with the lowest lattice oxygen concentrations exhibited the highest thermal conductivities. Hence, depending upon the surface oxygen content, different yttria levels were required for optimal thermal conductivities, i.e., higher surface oxygen contents required higher sintering additive levels than did low surface oxygen powders.
Databáze: OpenAIRE
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