Package structure of semiconductor die

A package structure of semiconductor die is disclosed, which comprises a substrate, a first heat sink sheet, a semiconductor die, a second heat sink sheet, and an encapsulant. The first heat sink sheet is disposed on the substrate, the semiconductor die is disposed on the first heat sink sheet. The second heat sink sheet has an exposed part and an internally-connected part. The internally-connected part extends from the rim of the exposed part, and contacts with the first heat sink sheet. The encapsulant wraps the semiconductor die, the first heat sink sheet, and the internally-connected part of the second heat sink sheet. The exposed part of the second heat sink part is exposed out of the encapsulant. With the heat-conduction path of the first heat sink sheet and the second heat sink sheet, the purpose of dissipating heat rapidly can be achieved.