SILICON NITRIDE SINTERED COMPACT, ITS PRODUCTION AND SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To obtain a silicon nitride sintered compact having high thermal conductivity and excellent mechanical characteristics. SOLUTION: This silicon nitride sintered compact comprises a silicon nitride particle having <=1,500 ppm total content of oxygen, Al, Ca and Fe and >=2 μm minor axis diameter. In this method for producing the silicon nitride sintered compact by adding one or more kinds of oxides of yttrium and/or lanthanoid group elements to silicon nitride powder to give raw material powder, molding the powder and then sintering the molding product, silicon nitride powder having <=300 ppm Al, <=1 wt.% oxygen and <=70% α ratio is used.