Power Cycling and Reliability Testing of Epoxy-Based Graphene Thermal Interface Materials

Abstract

We report on the lifespan evolution of thermal diffusivity and thermal conductivity in curing epoxy-based thermal interface materials with graphene fillers. The performance and reliability of graphene composites have been investigated in up to 500 power cycling measurements. The tested composites were prepared with an epoxy resin base and randomly oriented fillers consisting of a mixture of few-layer and single-layer graphene. The power cycling treatment procedure was conducted with a custom-built setup, while the thermal characteristics were determined using the “laser flash” method. The thermal conductivity and thermal diffusivity of these composites do not degrade but instead improve with power cycling. Among all tested filled samples with different graphene loading fractions, an enhancement in the thermal conductivity values of 15% to 25% has been observed. The obtained results suggest that epoxy-based thermal interface materials with graphene fillers undergo an interesting and little-studied intrinsic performance enhancement, which can have important implications for the development of next-generation thermal interface materials.

Noncured Graphene Thermal Interface Materials for High-Power Electronics: Minimizing the Thermal Contact Resistance

“…At the loading of , the increase in thermal conductivity slows down. This trend is consistent with prior studies for noncuring graphene composites [ 41 ], and different from that observed in curing epoxy composites with graphene [ 19 , 20 , 36 , 37 , 38 , 39 , 40 , 42 ]. In the cured solid TIMs, the thermal conductivity reveals linear to super-linear dependence on the filler loading [ 39 ].…”

“…It was also established that few-layer graphene (FLG) maintains high thermal conductivity, similar to bulk graphite owing to its smooth surface and, as a result, insignificant reduction in thermal conductivity due to the phonon—boundary scattering [ 27 , 28 , 29 , 30 ]. A mixture of single-layer graphene and FLG demonstrated the largest enhancement in the thermal conductivity of the TIM composites [ 19 , 20 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ]. In the context of thermal research and TIMs, we will refer to the processed mixture of graphene and FLG flakes with lateral dimensions in several μm range as graphene fillers .…”

Review of Graphene-based Thermal Polymer Nanocomposites: Current State of the Art and Future Prospects

“…This group worked on a power cycled reliability study on graphene-filled epoxy TIMs, without an adjoining junction [268]. The decision to not examine the TIM inside a junction sandwich stemmed from a desire to analyze the intrinsic thermal conductivity lifespan performance and.…”

Effect of Graphite Filler Type on the Thermal Conductivity and Mechanical Behavior of Polysulfone-Based Composites

“…Unfortunately, substantial micro-filler loadings (>50 wt.%) are commonly required to endow composites with exceptional thermal conductivity exceeding 5 W/m•K and, as a result, the mechanical and processing qualities will encounter some obstacles. Although nanofillers outperform conventional fillers in terms of increasing heat conductivity at low filler concentrations (less than 10 wt.%), their agglomeration tendency at higher filler concentrations due to robust self-interaction limits their application [15][16][17].…”

“…The effect of various shapes of carbon black nanoparticles was studied in [21], and it was discovered that particles with a branching shape build an electrically conductive framework more efficiently than particles with a spherical shape. The most effective construction of a conducting frame occurs as a synergistic effect of the interaction of several types of carbon filler, according to studies [17,23,24,28]. Carbon fillers have a good effect on the rheological features [23], mechanical properties [16,19,26], and fire resistance [25] of polymer composites, in addition to their electrically conductive capabilities.…”