| 摘要 |
PROBLEM TO BE SOLVED: To provide a low heat resistance circuit substrate increasing insulation reliability required for an insulating substrate without impairing high thermal conductivity of silicon nitride. SOLUTION: The silicon nitride circuit substrate is configured such that a metal circuit pattern is bonded to a surface of the silicon nitride substrate constituted of a silicon nitride sintered body with brazing filler metal and a nickel plating layer is formed on a surface of the circuit pattern. Two main surfaces of the silicon nitride substrate with the circuit pattern formed are different from each other in surface roughness, the surface roughness Ra of the main surface which is smaller in surface roughness is at least 0.2μm and not more than 1.0μm, the creeping distance of the main surface which is smaller in surface roughness is larger than the substrate thickness, and the thickness of the silicon nitride substrate is 0.2-1.0 mm. COPYRIGHT: (C)2011,JPO&INPIT |
