Abstract: A double-side exposed semiconductor device includes an electric conductive first lead frame attached on top of a thermal conductive but electrical nonconductive second lead frame and a semiconductor chip flipped and attached on top of the first lead frame. The gate and source electrodes on top of the flipped chip form electrical connections with gate and source pins of the first lead frame respectively. The flipped chip and center portions of the first and second lead frames are then encapsulated with a molding compound, such that the heat sink formed at the center of the second lead frame and the drain electrode at bottom of the semiconductor chip are exposed on two opposite sides of the semiconductor device. Thus, heat dissipation performance of the semiconductor device is effectively improved without increasing the size of the semiconductor device.