A package substrate for chip/chips package wrapped by a molding compound is disclosed. The molding compound functions as a stiffener for the thin film package substrate. One embodiment discloses at least one redistribution layer (RDL) is prepared and the RDL is wrapped by a molding compound. The molding compound wraps four lateral sides and bottom side of the RDL. A top side of the RDL is made for a chip to mount and a bottom side of the RDL is planted a plurality of solder balls so that the bottom side of the chip package is adaptive to mount onto a system board in a later process.