Abstract: A bolster plate apparatus, used to secure a semiconductor device intermediate a printed circuit board and a heat sink apparatus, includes either an indentation or an open aperture into which a radio frequency absorptive material may be disposed. The absorptive material may be a ferrite material specifically selected to absorb frequencies in the range of the second to fourth harmonic of the processor clock signal frequency. The type of the ferrite material implanted in the bolster plate is selected to maximize the absorption of radio frequency energy, particularly that emitted at the pad vias on the underside of the printed circuit board, without affecting the signal integrity of the other pad connections. The shape of the cutout or aperture is also defined by the arrangement of RF emitting pads on the underside of the printed circuit board.