A semiconductor package subassembly includes a die affixed to, and electrically interconnected with, a die attach side of a first package substrate, and a second substrate having a first side and a second (“land”) side, mounted over the first package with the first side of the second substrate facing the die attach side of the first package substrate, and supported by a spacer or a spacer assembly. Z-interconnection of the package and the substrate is by wire bonds connecting the first and second substrates. The assembly is encapsulated in such a way that both the land side of the second substrate (one side of the assembly) and a portion of the land side of the first package substrate (on the opposite side of the assembly) are exposed, so that second level interconnection and interconnection with additional components may be made.