Aging and Degradation Behaviour of Graphene-Enhanced Thermal Interface Materials for Large Power Electronics Module Cooling Applications

In this work, graphene-enhanced thermal interface materials (GT-TIM) were investigated for their thermal stability by employing isothermal calorimetry and thermogravimetric analysis. Moreover, the potential for incorporating GT-TIM in electronics packaging processes was evaluated by subjecting samples to industrially standardised reflow heat profiles before tensile stress and thermal testing. Finally, we performed reliability tests on GT-TIM regarding the thermal impedance of samples subjected to isotherms around decomposition temperatures. The results indicate that GT-TIM is stable up to 180°C and can withstand standardised reflow processes and exposure to elevated temperatures in the 150°C to 200 °C range with only a 10-20% increase in thermal impedance. The excellent thermal stability and performance of GT-TIM at these temperatures would make it a promising alternative within high-power dissipation to replace solder foils for TIM1 and thermal pastes, thermal putties, phase change materials (PCMs) as well as low thermal performance pads in TIM1.5 and TIM2 application in an electronic system.