A method for assembling a stackable semiconductor package includes providing a substrate having a first surface and a second surface. The first surface includes bond pads and one or more die pads. Conductive bumps are formed on the bond pads and one or more semiconductor dies are attached to the one or more die pads. The first surface of the substrate, the semiconductor dies and the conductive bumps are placed in a side-gate molding cast and a mold material is supplied to the first surface of the substrate to form a stackable semiconductor package. Similarly formed semiconductor packages may be stacked, one on another to form a stacked semiconductor package.