CIRCUIT BASE PLATE FOR POWER MODULE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a circuit base plate for a power module excellent in peeling strength and a high heat cycle property by keeping a mass ratio of B in BN remaining in the surface layer of a ceramic base plate consisting of a nitride as a main component to a set value or less. SOLUTION: This circuit base plate for a powder module using a ceramic base plate consisting of a nitride such as AlN or Si3 N4 as a main component, uses a base plate having <=50×10<-6> B/Al ratio and <=50×10<-6> B/Si in as ratios of major metal components in the ceramic to B in BN remaining in the surface layer measured by intensity ratios of a fluorescent X-ray. The circuit base plate having a prescribed circuit is obtained by joining a copper plate to at least one of the circuit base plate through a solder containing at least one kind of active metals of Ti, Zr and Hf by firing in vacuum, and performing an etching treatment.