| 摘要 |
PROBLEM TO BE SOLVED: To produce a sintered body having a new structure and a >=170W/m.K thermal conductivity with enhanced productivity on an industrial scale by utilizing a recovered powder and also to provide a circuit board having excellent heat radiating characteristics and high reliability. SOLUTION: The production of this sintered body which has <=2.0wt.% of the total oxygen content, <0.6wt.% of the content of oxygen that is dissolved within each of the aluminum nitride particles to form a solid solution and also, a >=170W/m.K thermal conductivity comprises: preliminarily calcining a formed body contg. an aluminum nitride powder having a <=1.0wt.% oxygen content, an yttria powder having a 1 to 5μm average particle size and an organic binder to form a dewaxed body having a <=2.5wt.% oxygen content; and thereafter, maintaining the temp. of the dewaxed body within the range of 1730 to 1800 deg.C for 3 to 9hr in a non-oxidizing atmosphere to sinter the dewaxed body and to produce the objective aluminum nitride sintered body. At this time, as a part or all of the aluminum nitride powder, a recovered powder having a <=1.0wt.% oxygen content is utilized. This circuit board is obtained by forming a metal circuit on the surface of the aluminum nitride sintered body. |
