Production manner of the nitriding silicon substrate and the nitriding silicon substrate and circuit substrate null nitriding silicon

摘要

PROBLEM TO BE SOLVED: To obtain a silicon nitride substrate having a high thermal conductivity and a required bending strength, improved in heat cycle resistance when bonding a copper plate to the silicon nitride substrate, and attaining long lasting and stable use when using a manufacturing method of laminating and sintering a plurality green sheets.;SOLUTION: The mean particle diameter of a separated material made of BN (boron nitride) is not more than 20 μm. In the sintering process, in silicon nitride particles, the area ratio of columnar crystal particles, each being 0.5-5 μm in minor axis a and at least 2 in ratio (b/a) of the major axis b to the minor axis a, is at least 30%. In the removing working process, a surface of a silicon nitride sinterd body is removed and worked such that in the ratio to BN left on a substrate surface, the ratio (B/Si) of the fluorescent X-ray intensity of boron (B) to the fluorescent X-ray intensity of silicon (Si) exceeds 6.5×10^-5 and is not more than 300×10^-5, and an arithmetic mean roughness Ra of the silicon nitride substrate surface is 0.3-2 μm.;COPYRIGHT: (C)2012,JPO&INPIT