A Modified Theoretical Model to Predict the Thermal Interface Conductance Considering Interface Roughness

TL;DR

This paper introduces a new mixed mismatch model that predicts thermal interface conductance by incorporating interface roughness, bridging the gap between existing models and real-world rough interfaces, validated by simulations and experiments.

Contribution

The paper presents a modified model that accounts for interface roughness by combining specular and diffuse transmissions, improving prediction accuracy over traditional models.

Findings

The mixed mismatch model accurately predicts thermal conductance.

Model results align well with molecular dynamics simulations.

Experimental data validate the model's effectiveness.

Abstract

The acoustic mismatch model and the diffuse mismatch model have been widely used to predict the thermal interface conductance. However, the acoustic mismatch model (diffuse mismatch model) is based on the hypothesis of a perfectly smooth (completely disordered) interface. Here, we present a new modified model, named as the mixed mismatch model, which considers the roughness/bonding at the interface. By taking partially specular and partially diffuse transmissions into account, the mixed mismatch model can predict the thermal interface conductance with arbitrary roughness. The proportions of specular and diffuse transmission are determined by the interface roughness which is described by the interfacial density of states. It shows that the predicted results of the mixed mismatch model match well with the values of molecular dynamics simulation and experimental data.