Reliability Characterization of Graphene Enhanced Thermal Interface Material for Electronics Cooling Applications

Graphene-based products are gaining popularity in thermal management applications in high performance electronics systems. The ultra-high thermal conductivity of graphene together with its relatively low density makes it a suitable material for reaching high cooling capability in lightweight applications. An example of products that are starting to enter the market is graphene enhanced thermal interface materials (TIMs). Pristine graphene enhanced TIMs are well characterized and show high thermal conductivity and low thermal interface resistance. Before these TIMs can take the next step from being a niche product to reach high volume sales on the market, it needs to be proven that they have stable performance over time when conditioned and aged according to industry reliability standards. In this work, a set of customized test rigs was designed, and graphene enhanced TIMs of three different thicknesses were tested. The TIMs were compressed by 30% and then subjected to three different industry standard reliability tests; thermal aging, temperature cycling and damp heat. The thermal resistance was measured sequentially during each test to monitor change over time. The reliability tests are still ongoing and so far the tested graphene enhanced TIMs have stable performance over time with some observable trends for the different tests. At the current test time the maximum degradation in thermal resistance is 13%, measured after 511 cycles in the thermal cycling test. The used test method is deemed promising for reliability comparison and future requirement standardization on thermal pads