Patent ID: 7817427

Claim:
A fastener for securing a heat sink to a printed circuit board, comprising: a fastener post comprising a shaft and a tapered portion, the tapered portion extending from an end of the shaft, a diameter of the tapered portion gradually increasing along a direction away from the shaft, with a threaded portion formed on another end of the shaft opposite to the tapered portion; a sleeve capable of receiving the fastener post therein, the sleeve comprising a smooth portion and a clamp portion corresponding to the tapered portion of the fastener post, the clamp portion comprising a plurality of resilient strips spaced from each other, and each of the resilient strips having a free end away from the smooth portion; a nut configured to be threaded onto the threaded portion; and an elastic element disposed around the sleeve, wherein, when the nut is threaded to compress the elastic element, resilient force generated by the compressed elastic element impels the tapered portion of the fastener post into the sleeve such that the strips of the clamp portion of the sleeve tilted outwardly.