A heat sink assembly for dissipating heat from an electronic component (12) mounted on a printed circuit board (10) includes a heat sink (20) resting on the electronic component, and a fastener assembly (30) for securing the heat sink to the electronic component. The fastener assembly includes a hollow post (36) having a threaded hole (360) defined therein, a screw (32) threadedly engaged in the threaded hole, a coil spring (34) compressibly disposed between the heat sink and a top portion of the screw, and a latch (38) pivotably engaging with a bottom portion of the post. When the screw moves downwardly towards the printed circuit board, the latch is pushed by the screw to rotate and press the heat sink towards the printed circuit board, thus securing the heat sink to the electronic component.