| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively produce a silicon nitride sintered compact high in thermal conductivity and suitable to a circuit board. SOLUTION: This sintered compact comprises 90-99 mol.% silicon nitride, 1-10 mol.% at least one of yttrium (Y) and lanthanoids group elements in terms of each oxide compd., furthermore 0-4 mol.% at least one selected from Hf, Ti, Zr in terms of each oxide compd. and has <=100 cm<-1> absorption coefficient for a light of 4 μm wave length. A circuit board is produced by using the sintered compact. In this method, the sintered compact is produced by adjusting a composition mol ratio of SiO2 /(Re2 +SiO2 ) to 0.05-0.5 and sintering it at 1800-2000 deg.C in nitrogen atmosphere. |
