Thermal transport properties of several thermal greases with applications in electronic packaging have been characterized at room temperature using the hot disk technique, which is a transient plane source technique for rapid thermal conductivity and thermal diffusivity measurement. In this technique, the hot disk sensor serves as a heat source and a thermometer. During the measurement, the sensor is sandwiched between two halves of a sample, and a constant current is supplied to the sensor. The temperature increase at the sensor surface is strongly dependent on the thermal transport properties of the surrounding material. By monitoring the temperature increase as a function of time, one can determine the thermal conductivity and the thermal diffusivity of the surrounding material with high accuracy. The results on thermal greases are in good agreement with supplier data, which were obtained by another method. (c) 2005 Elsevier B.V. All rights reserved.