| 摘要 |
PURPOSE:To enhance thermal conductivity by mixing AlN, metallic Yb or its compd. and metallic Ca or its compd. and molding this mixture and thereafter calcining this molded body in the N2-contg. nonoxidative atmosphere and regulating the contents of Yb and Ca to the specified value or more. CONSTITUTION:The mixture of 83 to 97wt.% (hereinafter %)AlN powder, 3 to 15% rare earth metallic compd. powder such as Yb2O3 which is a sintering adjuvant and 0.01 to 2% alkaline earth metallic compd. powder such as CaO is molded. Thereafter this molded body is raised in temp. to 1500 to 1700 deg.C from 1200 deg.C at the velocity of mean 40 deg.C/min or below in the nonoxidative atmosphere contg. gaseous N2 of >=1Torr and calcined. After calcination, this molded body is lowered in temp. to 1200 deg.C at the velocity of mean 40 deg.C/min or below and thereafter cooled. An AlN-based sintered body is obtained which incorporates >=0.5% Yb2O3 expressed in terms of metallic Yb and >=0.005% CaO expressed in terms of metallic Ca and has 3.2 to 3.6g/cm<3> and >=120W/m.K thermal conductivity. |
