| 摘要 |
PURPOSE:To improve the heat conductivity by adding a sintering aid to AlN powder, press-forming the mixture, primarily sintering the formed body in a reducing atmosphere, crushing the sintered body, adding a sintering aid to the crushed material, press-forming the mixture and then secondarily sintering the formed body in a reducing atmosphere. CONSTITUTION:From 0.1 to 20wt.% of a sintering aid selected from the alkaline- earth metal compds. such as CaO and the rare-earth compds. such as Y2O3 is added to the AlN powder having about 0.05-1mum average grain diameter, and the mixture is press-formed. The formed body is primarily sintered at 1650-2050 C for 0.5-6hr in a gaseous reducing atmosphere of CO, H2 etc. The sintered body is then crushed in a gaseous nonoxidizing atmosphere of Ar, etc., to obtain the crushed material having about 1-10mum average grain diameter. A sintering aid is added by 0.05-10% to the crushed material, and the mixture is press-formed. The formed body is secondarily sintered at 1650-2050 deg.C for >=0.5hr in a reducing atmosphere once or more than once to obtain an AlN sintered body contg. about 100ppm O2 and having >=250W/kW heat conductivity. |
