Modelling the Compressive Deformation of Metal Micro-Textured Thermal Interface Materials using SEM Geometry Reconstruction

Idealized and simplified geometries are commonly used in finite element models to ease model creation and meshing. However, at smaller length-scales, the influence of geometrical imperfections and defects can significantly affect the accuracy of the model predictions. This work details the modelling techniques required to achieve an accurate prediction of the mechanical behaviour of metal micro-textured thermal interface material (MMT-TIM) structures as they undergo compressive deformation. Of particular significance is the development of a novel and practical technique for accurately creating detailed micro-scale geometries for finite element modelling applications. This technique relies on an SEM stereoscopic surface reconstruction methodology and is extended here to create solid geometries amenable to direct simulation by finite element software tools. By accurately characterizing the geometry over the relevant length-scales, a dramatically improved prediction of the mechanical response of these structures is attained compared to models employing idealized geometries. Accurate mechanical models enable the subsequent heat transfer modelling of these materials to be achieved with a corresponding high degree of accuracy. The value of the geometry reconstruction technique for other applications is also discussed.