An electrical connector assembly electrically connecting a CPU and a printed circuit board includes an electrical connector mounted on the printed circuit board, and a heat dissipating device mounted upon the CPU. The heat dissipating device includes a load plate, a heat pipe, and a heat plate. The load plate is mounted upon the CPU under condition that heat generated from the CPU is absorbed by the heat pipe and the heat plate. The load plate is sandwiched between the heat plate and the heat pipe. The load plate has two clips each of which has two cantilever arms extending toward and engaging with the other clip.