To prevent occurrence of distortion in a semiconductor cooling device and
to prevent a semiconductor chip from being separated away from the
semiconductor cooling device in case the semiconductor chip and the
semiconductor cooling device are thermally expanded, a semiconductor
cooling device includes at least an upper plate, an intermediate plate
and a lower plate, and has a coolant inlet portion, an outlet portion and
a flow passage portion. The upper plate and the lower plate are composite
plates constituted by plating copper maintaining a thickness of not
smaller than 0.05 mm on one surface or on both surfaces of auxiliary
plates made of a material having a tensile strength of not smaller than
1000 N/mm.sup.2, a heat conductivity of not smaller than 100 W/mK and a
coefficient of thermal expansion of not larger than 6.0 ppm/.degree. C.