A semiconductor package includes a substrate board and a semiconductor die attached to a top surface of that substrate board. A heat spreader is provided over the semiconductor die. A stiffening ring is positioned surrounding the semiconductor die, the stiffening ring being attached to the top surface of the substrate board and attached to a bottom surface of the plate portion of the heat spreader. Space is left on the board outside of the stiffening ring to support the installation of passive components to the substrate board. An external ring may be included, with that external ring being interconnected to the stiffening ring by a set of tie bars. Alternatively, the heat spreader includes an integrally formed peripheral sidewall portion.