An electronic device includes a circuit board comprising a first surface and a second surface, a heat sink positioned on the first surface, and a support positioned on the second surface to support the circuit board. The circuit board includes a pair of first locating holes extending through the first surface and the second surface. The heat sink includes a pair of second locating holes corresponding to the first locating holes. The support includes a pair of locating posts projecting from a pair of diagonal corners thereof and extending through the corresponding first and second locating holes to limit unwanted movement of the heat sink and a shim projecting from a center thereof to prevent the circuit board from flexing. Dimensions of the shim are contoured to provide compensation for bending of the support under an applied load.