The invention provides a semiconductor package assembly. The semiconductor package assembly includes a substrate having a first pad and a second pad thereon. A logic die is mounted on the substrate. The logic die includes a first logic die pad coupled to the first pad. A memory die is mounted on the substrate. The memory die includes a first memory die pad. A first redistribution layer (RDL) trace has a first terminal and a second terminal. The first terminal is coupled to the first pad through the first memory die pad. The second terminal is coupled to the second pad rather than the first pad.