Modelling and Experimental Characterization of Metal Micro-Structured Thermal Interface Materials

A novel metal micro-structured thermal interface material (MMS-TIM) has been developed to address some of the shortcomings of conventional TIMs. These materials consist of arrays of small-scale metal features that plastically deform when compressed between mating surfaces, conforming to the surface asperities of the contacting bodies and resulting in a low-thermal resistance bondline. The present work details the development of an accurate thermal model to predict the thermal resistance and effective thermal conductivity of the metal geometries as they undergo large plastic deformations. The main challenge of characterizing the thermal contact resistance of these structures was addressed by employing a numerical model to characterize the bulk thermal resistance and estimate the contribution of thermal contact resistance. Furthermore a correlation that relates electrical and thermal contact resistance for these MMS-TIMs was developed that adequately predicted MMS-TIM properties for several different geometries. A comparison to a commercially available graphite TIM is made as well as suggestions for optimizing MMS-TIM designs.