Addition of Thermal Energy Storage to Thermal Interface Materials Using Dispersed Encapsulated Phase Change Materials

Encapsulated phase change materials (ePCMs) achieve a stable PCM system by creating spherical particles with a PCM core and a protective shell material, containing the PCM through solid and liquid phases. These particles can be introduced into existing materials to form ePCM composites, combining thermal energy storage with the original material?s functionality. Extra thermal buffering can be directly added into energy dense systems by strategically placing composites with ePCM particles in critical thermally active locations. The addition of thermal energy storage to these locations will reduce localized thermal gradients and improve system reliability. This work introduces ePCMs, comprised of a paraffin core and titania shell, into thermal interface materials (TIMs) to create a more resilient and effective thermal attachment layer. By dispersing these ePCMs within different thermal pastes, the sensible and latent energy storage mechanisms of the full composites are linearly increased as a function of particle concentration. The thermal conductivity of the composites decreases due to the inclusion of ePCMs with poor thermal conduction enhancement qualities, leaving room for further ePCM improvement. The viscosity of each TIM rises as the ePCM concentration increases, creating a balance between mechanical compliance and added thermal energy storage. Though not currently an optimal design for this material combination, the ePCM composites are compared to existing PCM solutions for thermal interface materials. Integrating ePCMs into TIMs directly adds thermal capacitance to energy dense electronic systems by leveraging the favorable properties of both materials. The resulting composite is a low cost solution for thermal attachment layers with significant flexibility in material combination choices for future composites of both ePCM additives and TIM bases.