| 摘要 |
PURPOSE:To obtain an AlN sintered compact consisting of a specific crystalline body excellent in heat conductivity by sintering a formed body of raw material powder consisting essentially of Al and N at a specific temperature and then lowering temperature of the sintered body at a specific rate. CONSTITUTION:A formed body of raw material powder consisting essentially of Al and N is sintered at 1700-1900 deg.C and then temperature of the sintered compact is lowered at a rate of <=5 deg.C/min until at least 1500 deg.C to provide the objective sintered compact. In the sintered compact, a ratio (b/a) of length of axis (a) and axis (b) is 1.000 in the vicinity of the center of AlN crystal and 0.997-1.003 in the vicinity of grain boundary phase among axis (a), axis (b) and axis (c) which are three edges of unit lattice of unit crystal of AlN crystal belonging to wurtzite type hexagonal system. According to the above- mentioned method, heat conductivity of AlN sintered compact is remarkably improved and mechanical strength thereof can be improved and AlN sintered compact suitable as a heat release plate material or substrate material for semiconductor and having high heat conductivity can be provided. |
