| 摘要 |
PROBLEM TO BE SOLVED: 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. SOLUTION: This aluminum nitride burning furnace is constituted so as to contain an alumina refractory material layer containing <=0.5wt.% SiO2 , <=0.5wt.% Fe2 O3 and other unavoidably impurities and a graphite layer which is arranged at a position becoming 1000-1500 deg.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 deg.C burning temperature. As steam is decomposed to H2 and CO2 by the graphite layer, AlN is not oxidized. |
