An integrated circuit (IC) device includes a polymer substrate having a topside surface and a bottomside surface opposite the topside surface, a plurality of through-holes that extend from the topside surface to the bottomside surface, and a plurality of bottom metal pads on the bottomside surface positioned over the plurality of through-holes. At least one IC die having an active topside including a plurality of bond pads and a second side is affixed to the topside surface. Bonding features are coupled to the plurality of bond pads for coupling respective ones of the plurality of bond pads to the plurality bottom metal pads. The bonding features extend into the through-holes to contact the bottom metal pads.