A package assembly and a method for manufacturing the same are disclosed. The package assembly includes semiconductor chips, encapsulant layers, and a chip carrier. The plurality of semiconductor chips are stacked in a plurality of levels, including a lowermost level and at least one upper level. The plurality of encapsulant layers cover respective levels of semiconductor chips. The chip carrier is used for mounting lowermost-level semiconductor chips. At least one upper-level semiconductor chips are electrically coupled to the chip carrier by conductive traces. The conductive traces include extension conductors on a surface of a lower-level encapsulant layer and conductive vias which penetrate the lower-level encapsulant layer and are exposed at a bottom surface of the package assembly. The package assembly has improved high-frequency performance while having a small size and supporting multifunctionality.