A memory module assembly includes a printed circuit board (10) having a heat-generating electronic component (50) thereon, a pair of heat-dissipating plates (20) attached on the printed circuit board, and a pair of clamps (30) clamping the heat-dissipating plates and the printed circuit board therebetween. Each heat-dissipating plate includes a pair of supporters (28) and a handle (24) rotatably engaging with the supporters. The heat-dissipating plates are installed on the opposite sides of the printed circuit board by exerting a force to the handles to make them move toward each other wherein the force overcomes the spring force of the clamps.