High-Temperature Electromagnetic and Thermal Characteristics of Graphene Composites

TL;DR

This paper presents a scalable method for creating graphene-epoxy composites with high EMI shielding and thermal conductivity, maintaining performance at elevated temperatures, suitable for microwave packaging applications.

Contribution

It introduces a scalable synthesis technique for graphene-epoxy composites with enhanced EMI shielding and thermal properties at high temperatures.

Findings

Achieved ~65 dB EMI shielding at 8.2-12.4 GHz in 1 mm thickness

Thermal conductivity increased by a factor of 41 compared to pristine epoxy

EMI shielding efficiency improves with temperature up to 520 K

Abstract

We describe a method for scalable synthesis of epoxy composites with graphene and few-layer graphene fillers, and report on the electromagnetic interference (EMI) shielding and thermal properties of such composites at elevated temperatures. The tested materials reveal excellent total EMI shielding of ~65 dB (~105 dB) at a thickness of 1 mm(~2 mm) in the X-band frequency range of f=8.2 GHz - 12.4 GHz. The room-temperature cross-plane thermal conductivity of the composite with ~19.5 vol.% of fillers was determined to be ~11.2 W/mK, which is a factor of x41 larger than that of the pristine epoxy. Interestingly, the EMI shielding efficiency improves further as the temperature increases to 520 K while the thermal conductivity remains approximately constant. The excellent EMI shielding and heat conduction characteristics of such multifunctional graphene composites at elevated temperatures are promising for packaging applications of microwave components where EMI shielding and thermal management are important design considerations.