A multi-chip semiconductor device comprises a thermally enhanced structure, a first semiconductor chip, a second semiconductor chip, an encapsulation layer formed on top of the first semiconductor chip and the second semiconductor chip. The multi-chip semiconductor device further comprises a plurality of thermal vias formed in the encapsulation layer. The thermally enhanced structure comprises a heat sink block attached to a first semiconductor die. The heat sink block may further comprise a variety of thermal vias and thermal openings. By employing the thermal enhanced structure, the thermal performance of the multi-chip semiconductor device can be improved.