Modeling and Experimental Characterization of Metal Microtextured Thermal Interface Materials

Abstract

A metal mierotextured thermal interface material (MMT-TIM) has been proposed to address some of the shortcomings of conventional TIMs. These materials consist of arrays of small-scale metal features that plastically deform when compressed hetu'een mating surfaces, conforming to the surface asperities of the contacting bodies and resulting in a low-thermal 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 MMT-TlMs 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 MMT-TIMs was developed that adequately predicted MMT-TIM properties for several different geometries. A comparison to a commercially available graphite TIM is made as well as suggestions for optimizing future MMT-TIM designs.

Novel nanostructured thermal interface materials: a review

“…A metal foil is textured with microfeatures such as cones which deform and conform to a surface under pressure. Several different foil geometries have been investigated [179], and while the performance of these metal micro-textured TIMs is much lower than the highest-performing TIMs, on the order of 100 Kmm 2 W −1 , it compares favourably compared to common graphite pads [178, 180]. Further optimisation and a more facile manufacturing method could make this a viable TIM in some applications.…”

Present and future thermal interface materials for electronic devices

“…Metal foil with microtextured surface have been proposed by Kempers et al . where the authors modelled and fabricated 36 and 28 µm thick Ag foils with cones approximately 0.95 mm tall and 1 mm base on a 2 mm pitch [99]. The concept was aimed to target the interfacial contact resistance and associated intimate contact area by using a compliant metal and then plastically deforming the small structures when the two opposing faces were compressed.…”

Demonstration of a Compliant Microspring Array as a Thermal Interface Material for Pluggable Optoelectronic Transceiver Modules

“…Vertically aligned carbon nanotubes (CNTs) have extremely high axial thermal conductivity [22,23] and can be bonded to mating surfaces to enhance contact thermal conductance [24,25]. Metal nanowires [26,27] and nanotubes [28,29] having intrinsically high material thermal conductivity can be designed to have high mechanical compliance by engineering their shape/structure. These TIMs have reported extraordinary thermal performance, but permanent bonds must be created between the mating surfaces, which is not possible for pluggable optical modules.…”