A package process is provided. The package process includes: disposing a semiconductor substrate on a carrier, wherein the semiconductor substrate has plural contacts at a side facing the carrier; thinning the semiconductor substrate from a back side of the semiconductor substrate and then forming plural through silicon vias in the thinned semiconductor substrate; forming plural first pads on the semiconductor substrate, wherein the first pads respectively connected to the through silicon vias; bonding plural chips to the semiconductor substrate, wherein the chips are electrically connected to the corresponding pads; forming a molding compound on the semiconductor substrate to cover the chips and the first pads; separating the semiconductor substrate and the carrier and then forming plural solder balls on the semiconductor substrate; and sawing the molding compound and the semiconductor substrate.