Patent attributes
A power semiconductor module with its thermal resistance and overall size reduced. Insulating substrates with electrode metal layers disposed thereon are joined to both the surfaces of a power semiconductor chip by using, for example, soldering. Metal layers are disposed also on the reverse surfaces of the insulating substrates and the metal layers are joined to the heat spreaders by using brazing. Heat radiating fins are provided on the heat radiating surface of at least one of the heat spreaders. The heat radiating side of each of the heat spreaders is covered by a casing to form a refrigerant chamber through which refrigerant flows to remove heat transmitted from the semiconductor chip to the heat spreader.