| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an aluminum nitride sintered body which has a flat and smooth surface without being polished after firing and exhibits high light transmittance characteristics. <P>SOLUTION: Specifically disclosed is an aluminum nitride sintered body characterized by having an oxygen concentration of not more than 450 ppm, a concentration of impurity elements other than oxygen, nitrogen and aluminum of not more than 350 ppm, and an average crystal grain size of 2 to 20 μm. This aluminum nitride sintered body is further characterized in that the surface thereof which is not polished after firing has an arithmetical mean roughness Ra of not more than 1 μm and a maximum height Rz of not more than 10 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT |
