Ceramic circuit board and method for producing same

Abstract

[Problem] To obtain a ceramic circuit board having superior crack-resistance with respect to ultrasonic bonding. [Solution] The abovementioned problem is solved by a ceramic circuit board characterized in that a metal circuit board is bonded to one surface of a ceramic substrate and a metal heat radiation plate is bonded to the other surface of the ceramic substrate, wherein the crystal grain size in the metal circuit board is at least 20 μm and at most 70 μm. This ceramic circuit board can be manufactured by arranging the metal circuit board on one surface of the ceramic substrate and arranging the metal heat radiation plate on the other surface of the ceramic substrate, and bonding in a vacuum of at most 1×10−3 Pa, at a bonding temperature of at least 780° C. and at most 850° C., for a retention time of at least 10 minutes and at most 60 minutes.

Dependencies are inferred from the claim text.