To obtain an aluminum nitride sintered compact excellent in compactness and heat conductivity, and capable of preventing the compact from discoloration and warp by constituting a heat insulating layer so as to contain a specific alumina refractory material layer and a graphite layer.
This aluminum nitride burning furnace is constituted so as to contain an alumina refractory material layer containing ≤0.5wt.% SiO2, ≤0.5wt.% Fe2O3 and other unavoidably impurities and a graphite layer which is arranged at a position becoming 1000-1500°C temperature during the burning treatment, in a heat insulating layer thereof. A heater consisting of W, Mo or their alloy is installed in the furnace. The burning is conducted under an inert atmosphere or the inert atmosphere containing ≤3vol.% hydrogen. A typical AlN burning furnace is shown in the figure. An AlN compact 16 is loaded at the inside of a burning furnace 10, the inert gas is introduced through a gas introducing pipe 14 and a gas discharging pipe 15, and the furnace is heated by a heater 17 to attain 1550-1650°C burning temperature. As steam is decomposed to H2 and CO2 by the graphite layer, AlN is not oxidized.
TERAO KOICHI
UCHIYAMA ICHIRO
