Study on Thermal Interface Material with Carbon Nanotubes and Carbon Black in High-Brightness LED Packaging with Flip-Chip

Abstract

MWNT and carbon black were used to improve the thermal performance of TIM in high-brightness light emitter diode (HB-LED) packaging. Nitric acid treatment of CNT and optimized mixing procedure were used to help disperse the CNT and carbon black. SEM images indicated the uniform dispersion and strong bonding of fillers in the epoxy resin. 100% improvement of the thermal conductivity was achieved by the developed thermal interface material (TIM) with 2 wt% MWNT and 10 wt% carbon black. The curing temperature of 140°C and glass transition temperature of 147°C indicated it was suitable to be used in HB-LED packaging. The blue color flip chip LED packages were fabricated to evaluate the thermal performance of TIM. The output light power of the 1×1mm 2 HB-LED device with the developed TIM can achieve 62mW with the input current of 300mA.