Sn -decorated boron nitride nanotubes reinforced liquid metal thermal interface materials for semiconductor packaging

Liquid metal (LM) with notable thermal conductivity might be a promising candidate for the thermal management of CPU and GPU used for AI since conventional polymer-based thermal interface materials are not sufficient to dissipate the heat produced by these advanced chips. However, it also has disadvantages, such as leakage, surface-spreading concerns, and processability difficulties due to their inherent high surface tension. The proposed solution to mitigate these issues might be metallic particle incorporation with LM, but the incorporation of those metal particles in general causes the intermetallic reactions resulting the deteriorated thermal performance and processibility. Here, we suggest a facile and straightforward scheme using a mixture of boron nitride nanotubes (BNNT) with LM, while in-situ decoration of Sn (tin) nanoparticles onto the surface of BNNT (BNNT-Sn) through reduction reaction and electrostatic attraction improves its dispersion and wettability in the LM matrix. We report for the first time the BNNT-Sn achieves superior phonon conduction pathways through the nanotubes by increasing the thermal conductivity as high as 30%, and more importantly, the wettability and processibility properties were also enhanced by increasing the viscosity to 180,500 ± 750 mPas from 2,400 mPas for neat LM with just 1.0 wt% of BNNT-Sn assimilation, with an improved rigidity evading leakage and adhesion as well. These improvements can be correlated with the intrinsic attributes of BNNT, such as an optimal aspect ratio and inherent thermal conductivity that contributed to the improvement of viscosity and thermal conduction.