Disclosed herein is a power module package including a heat radiating plate including a step difference portion around an edge portion thereof, a semiconductor chip mounted on a mounting surface of the heat radiating plate, an external connection terminal disposed on an outer periphery of the heat radiating plate, electrically connected to the semiconductor chip, and protruding outwards, a wire for electrical connection between the semiconductor chip and the external connection terminal; and a molding portion for encapsulation of the semiconductor chip and a portion of the heat radiating plate, and in particular, the molding portion does not intrude over an exposed surface of the lower portion of the heat radiating plate through the step difference portion. In addition, disclosed herein is a fabricating method for preventing flush of the molding portion on the exposed surface.