Abstract: A clip is configured for retaining a heat sink on a chip and socket combination. The clip includes an arcuate pressing portion, first and second engaging arms downwardly extending from opposite ends of the arcuate pressing portion, and a driving arm generally upwardly extending from a lower end of the second engaging arm. The clip engages with the socket by openings in the first and second engaging arms receiving projections on opposite edges of the socket. The arcuate pressing portion downwardly presses the heat sink toward the chip. The second engaging arm defines a slit above the hole thereof to reduce the rigidity thereof and the driving arm forms a rib to increase the rigidity thereof, thereby the driving arm having a greater rigidity than the second engaging arm. The driving arm is downwardly and outwardly movable to disengage the second engaging arm from the socket.