<p>With increased focus on smaller and faster electronic packages with high power densities, there is a need for the development of new packaging materials with lower thermal resistance.&nbsp; To this end, metal-based thermal paste, or similar thermal interface materials (TIMs) reinforced with excellent thermal conductivity materials such as multi-walled carbon nanotubes (MWCNTs), graphene nanoplatelets (GNPs), graphite-derived multilayer graphene (g-MLG), and coal-derived multilayer graphene (coal-MLG) offer an effective strategy to provide efficient paths for heat dissipation from a heat source. This study examines the thermal performance of these metal-based TIMs with MWCNTs, GNPs, g-MLG, and coal-MLG as additives. One of the problems experienced with these additives is their tendency to agglomerate in the matrix (thermal paste), which inhibits further improvement in thermal conductance, possible at higher loading fractions. Recently, in our laboratory, we have developed a novel one-pot process to synthesize multilayer graphene from coal. The coal-MLG so produced has been demonstrated to have an increased presence of phenolic groups on graphene surfaces, which, we believe, can lead to better dispersion of coal-MLG in the thermal paste. This, in turn, should permit the use of higher loading fractions of coal-MLG without the frequently encountered problem of agglomeration. We tested this hypothesis by evaluating the thermal conductance of these TIMs at different weight fractions of the carbonaceous materials by measuring the heat flow, in steady-state, through the TIM sandwiched between two metal blocks. &nbsp;First, we note that for different heat flux inputs used, the measured thermal conductance values were found to be independent of the heat flux. More importantly, the coal-MLG-based TIM provided the best enhancement in thermal conductance as compared to the other carbonaceous materials used as additives to the base thermal paste. Since the coal-MLG produced by our in-house uses a process, which is relatively much cheaper and more environment-friendly, we believe that these results would pave the path for enhanced thermally performing metal-based thermal pastes at a significantly lower cost.</p>

Thermal Performance of Different Carbonaceous Nanoparticles as Additives to Thermal Paste as an Interface Material

Paper Proceedings: https://asmedigitalcollection.asme.org/InterPACK/InterPACK2021/volume/85505

ASME 2021 International Electronic Packaging Technical Conference and Exhibition (InterPACK2021)

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