The heat transfer behavior for a novel micro-configured heat sink for cooling high flux micro-electronic components is proposed. The concept makes use of two-phase cooling, with large numbers of small cavities (e.g. pyramidal re-entrant cavities on the order of 10 m and up to 420 cavities per cm2) etched directly on the silicon wafer. Such cavities have been demonstrated to entrap vapor, and hence acting as stable nucleation sites. Another advantage is that the heat sink is integrated into the wafer itself, eliminating the additional resistance due to heat sink to heat source bonding. Parameters which would minimize temperature overshoot will be investigated, including shape, size and density of the etched features. Their effect on fully developed nucleate boiling will also be investigated.