| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a silicon nitride sintered compact combinedly having a thermal conductivity of ≥100 W/(m×K) and a bending strength of ≥600 MPa, to provide a method for manufacturing the same, and to provide a circuit board. <P>SOLUTION: In the silicon nitride sintered compact, Mg, Lu and at least one kind of element selected from rare earth elements (RE) including Y are added as sintering assistants, the sintered compact comprises Mg by 0.03 to 8.0 mol% expressed in terms of magnesium oxide (MgO), Lu by 0.14 to 1.30 mol% expressed in terms of lutetium oxide (Lu<SB>2</SB>O<SB>3</SB>) and at least one kind of element selected from rare earth elements (RE) by 0.12 to 1.30 mol% expressed in terms of oxide (RE<SB>x</SB>O<SB>y</SB>), and the balance βsilicon nitride. The sintered compact is composed of silicon nitride particles and a boundary phase. The total oxygen content in the sintered compact is ≤2.5 mass%, and at least Lu<SB>4</SB>Si<SB>2</SB>O<SB>7</SB>N<SB>2</SB>crystals are precipitated into the boundary phase. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
