To obtain a sintered compact having high thermal conductivity by making the sintered compact include a silicon nitride particle having a specific ppm or lower than it of the total content of oxygen, Al, Ca and Fe and a specific value or larger than it of a minor axis diameter orientated in one direction.
This silicon nitride sintered compact contains preferably 20-60 area % based on the whole silicon nitride sintered compact of a silicon nitride particle having ≤1,000 ppm total content of oxygen, Al, Ca and Fe and ≥2 μm minor axis diameter orientated in one direction. The ratio I (002)/I (200) of X-ray diffraction intensity I (200) of plane (002) of silicon nitride observed in the orientation direction to the X-ray diffraction intensity I (200) of plane (200) of silicon nitride is preferably ≥40. Silicon nitride powder comprising 2-30 wt.% of a silicon nitride particle having ≥2.5 average aspect ratio, containing ≤300 ppm of Al and ≤1 wt.% of oxygen and having ≥30% β ratio is mixed with one or more of yttrium and/or a rare earth element and its compound and sintered to give the objective silicon nitride sintered compact.
EMOTO HIDEYUKI
YOKOTA HIROSHI
IBUKIYAMA MASAHIRO
| JPH0930866A | 1997-02-04 |
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