| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon nitride ceramic substrate and its manufacturing method capable of controlling generation of leak current efficiently when various kinds of power modules are constituted using the silicon nitride ceramic substrates and improving insulation property and reliability of operation greatly even in the case of upgraded module in power and capacity. SOLUTION: The silicon nitride ceramic substrate 2 is characterized in that a silicon nitride sintered compact is provided with largest pore-size of <=0.3 μm in grain boundary phase, the value of leakage current of which is <=1000 nA, when ac voltage of 1.5 kV-100 Hz is impressed between surface and rear face of the silicon nitride sintered compact, at the temperature of 25 deg.C and humidity of 70%, the thermal conductivity of which is >=50 W/m.K, and the three-point bending strength of which is >=500 MPa. |
