Tailoring Three-Dimensional copper framework in polyamide 6 for High-Performance thermal management applications

Abstract

Polymer plays an essential role in efficient thermal management of high-performance electronic devices, but the cooling efficiency of polymer composites is limited by some technical difficulties, such as the lack of thermal transport pathways and high cost of nano filler. Herein, we introduced solid-state shear milling (S3M) technology to prepare copper flakes (Cu-f) and constructed an enhanced Cu flakes network through hot-pressing of Cu and polyamide 6 (PA6) particles with different melt temperature. The low melt temperature PA6 coating on Cu flake surface acted as a glue to tightly connect Cu flakes and high melt temperature PA6 particles, thus generating an enhanced filler network. This brings the PA6/Cu-f network composites with a record high thermal conductivity at 6.3 Wm−1Κ−1, which is 3 times higher than that of traditional PA6/Cu-s composites (1.8 Wm−1Κ−1) at 80 wt% Cu loading. Basing on Foygel’s model from effective medium approximation theory, the PA6/Cu-f network composites had a lower thermal contact resistance (Rc) of 9.8 × 103 KW−1 and interfacial thermal resistance (ITR) of 6.3 × 10−8 W−1m2K. In LED lamps cooling performance test, PA6/Cu-f network composite showed 15 °C lower than traditional PA6/Cu-s composite in operating temperature. We believed that with the excellent thermal management ability and low cost, the PA6/Cu-f network composites open up opportunities for efficient thermal management in high power density devices.