Abstract: A BGA package is disclosed including a base IC structure having a base substrate, with an opening running length-wise there through. A first semiconductor chip is mounted face-down on the base substrate so the bond pads thereof are accessible through the opening. The package also includes a secondary IC structure including a secondary substrate, having an opening running there through, and a second semiconductor chip. The second chip is mounted face-down on the secondary substrate so that the bond pads thereof are accessible through the opening in the secondary substrate. An encapsulant fills the opening in the secondary substrate and forms a substantially planar surface over the underside of the secondary substrate. The substantially planar surface is mounted to the first chip of the base IC structure through an adhesive. Wires connect a conductive portion of the secondary IC structure to a conductive portion of the base IC structure.