| 摘要 |
PROBLEM TO BE SOLVED: To obtain a heat dissipating component made of silicon nitride at a low cost, capable of being produced through calcining at a temperature of <=1800 deg.C and normal pressure, and having high thermal conductivity, and to provide a method for producing the same component. SOLUTION: This heat dissipating component made of silicon nitride is obtained by calcining a molded product which contains 70-95 mol.% Si3 N4 , 4-30 mol.% [rare earth metals (RE)+Mg] in terms of their oxides and in a mol ratio (RE2 O3 /MgO) of 0.1-15 in terms of RE2 O3 and MgO and <=1.0 mol.% Al in terms of its oxides in a non-oxidizing atmosphere at 1,650-1,800 deg.C and then by the heat treatment of the product at 1,100-1,600 deg.C for >=1 h. The resultant product has a relative density of >=90%, a surface roughness (Rmax) of <=10 μm on the calcined face and a thermal conductivity of >=50 W/(m.K), and contains crystalline phases comprising MgSiO3 , MgSiN2 in grain boundary layers. |
