Modeling and Experimental Characterization of Metal Microtextured Thermal Interface Materials

Abstract

A metal microtextured thermal interface material (MMTTIM) has been proposed to address some of the shortcomings of conventional TIMs. These materials consist of arrays of smallscale metal features that plastically deform when compressed between mating surfaces, conforming to the surface asperities of the contacting bodies and resulting in a lowthermal resistance assembly. The present work details the development of an accurate thermal model to predict the thermal resistance and effective thermal conductivity of the assembly (including contact and bulk thermal properties) as the MMTTIMs 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 MMTTIMs was developed that adequately predicted MMTTIM properties for several different geometries. A comparison to a commercially available graphite TIM is made as well as suggestions for optimizing future MMTTIM designs.