abstract |
Provided are a silicon nitride substrate and a silicon nitride circuit board with excellent electrical characteristics, and power control parts utilizing them. n A silicon nitride substrate comprises a silicon nitride sintered body obtainable by sintering a silicon nitride powder in the presence of a sintering aid comprising MgO, Y 2 O 3 and SiO 2 in a proportion of (1) MgO/(MgO+SiO 2 )=34-59 mol%, and (2) Y 2 O 3 /(Y 2 O 3 +SiO 2 )=50-66 mol%, and a silicon nitride circuit board utilizes it. |