Impingement cooling is an attractive method for individual IC cooling because of the uniformity and high values of the expected heat transfer coefficient. This paper presents spatially-averaged temperature measurements for DI water impingement from single micro jets with diameters smaller than 50 μm. The jets are circular orifices plasma etched into silicon. A heater chip is fabricated to simulate a high power IC while simultaneously measuring the temperature distribution around the impingement region. A hydrodynamic model is proposed for determining the pressure drop associated with jet formation. With a single 50 μm diameter DI water jet at 3.5 ml/min flow rate, up to 45 W/cm 2 heat flux has been removed with 80°C chip temperature rise. This research provides the first study of microscale liquid impingement cooling down to 14 μm diameter jets.