A mounting structure adapted for mounting an expansion card within a computer enclosure and configured to directly absorb and conduct heat from a heat source (such as an IC chip) on the card to the ambient atmosphere surrounding the enclosure. The mounting structure includes a mounting bracket, a heat sink adapted to contact a surface of the heat source on the expansion card, an extension interconnecting the heat sink and the mounting bracket, one or more features for conducting heat from the heat sink to the mounting bracket, and one or more features associated with the mounting bracket for dissipating heat from the mounting structure to the ambient atmosphere surrounding the enclosure.