A thin metallic sheet having an array of alternating domes, directed away from opposite sides of the sheet, to bridge a gap between a top surface of a processor package and a bottom surface of a heat sink. The sheet is positioned between the processor package and heat sink before securing the heat sink to the processor package. By pressing the processor package and heat sink together, the tops of the domes flatten out to maximize surface contact between a first side of the sheet and the top of the processor package, and between a second side of the sheet and the top of the heat sink.