Reducing thermal contact resistance by a novel elastomeric polyethylene glycol/unsaturated polyester resin/graphene thermal interface materials

Reducing thermal contact resistance (TCR) is an important way to enhance heat dissipation of electronic devices. Elastomer is easy to deform, increase the contact area and reduce the TCR, but its wetting condition is not satisfying. In this work, a novel elastomeric thermal interface materials (TIMs) polyethylene glycol/unsaturated polyester resin/graphene (PEG/UPR/G) was designed and prepared. With the increase of temperature, PEG near surface of PEG/UPR/G was released due to phase transformation, and a thin molten layer would be attached to the surface. By this way, the micro bumps on the solid surface were all soaked by the thin layer of molten PEG, which greatly reduced the TCR. In addition, the effect of temperature and pressure on TCR of elastomeric PEG/ UPR/G were studied. When the pressure increases from 10 Psi to 50 Psi (65 degrees C), TCR decreases from 11-14 K center dot cm2/W to 2-4 K center dot cm2/W. The TCR will be further reduced to 0.7-0.9 K center dot cm2/W (75 degrees C) due to the phase transition of PEG. Moreover, the heat dissipation effect of PEG/UPR/G was evaluated by infrared thermal imager. These results demonstrate that the total thermal resistance is the decisive factor for the final steady-state temperature and the time of unsteady heat transfer.