Designing thermal transport pathway: A molecularly designed Cu-MWCNT composite thin film with enhanced heat transfer

Over the past decade, electrothermal systems such as CPUs and power electronics have become more complex and powerful; however, they are also smaller in size and subject to much greater heat loads. Therefore, there has been a surge in demand for methods and materials for effective cooling with seamless interfaces and improved heat transfer properties. To design a conformal thermal interface material (TIM) with a high thermal conductivity, we performed molecular dynamics simulations of the behavior of Cu nanoparticles (CuNPs) and carbon nanotubes (CNTs) upon sintering. The numerical results provide insight into how CuNPs and CNTs form a composite and the expected performance of CuNP-CNT based TIMs. To fabricate molecularly designed nanocomposites with improved thermal conductivity and spreadability, we adopted an intense pulsed light (IPL)-based sintering method to prevent potential thermal decomposition of multi-walled CNTs (MWCNTs) at elevated sintering temperatures. We successfully demonstrated the fabrication of TIMs with much higher thermal conductivity (k = 34 W/m∙K). Heat transfer improvements were also tested using high thermal load applications, showing a 7 % increase in heat dissipation and more than 15 °C additional cooling compared to traditional TIMs. This study provides better guidance for the design and fabrication of nanomaterials with enhanced functionality by adopting molecular-level design.