| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a silicon nitride substrate having high strength, and in which warpage is properly regulated, to provide a method for producing the same, to provide a silicon nitride circuit board using the same, and to provide a semiconductor module. <P>SOLUTION: Silicon nitride raw material powder is blended with magnesium oxide of 3 to 4 wt.% and the oxide of at least one kind of rare earth element of 2 to 5 wt.% in such a manner that the total is controlled to 5 to 8 wt.%, so as to be a sheet molded body, and sintering is performed thereto. Thereafter, in a superimposed state, a plurality of the sintered compacts are heated at 1,550 to 1,700°C while applying a load of 0.5 to 6.0 kPa thereto, so as to produce a silicon nitride substrate comprising β type silicon nitride, yttrium (Y) and magnesium (Mg), and in which a variation coefficient showing the distribution of the Mg content in the surface is ≤0.20 and warpage is ≤2.0 μm/mm. <P>COPYRIGHT: (C)2009,JPO&INPIT |
