To improve the thermal conductance of epoxy used in the high-brightness light emitting diode (HB-LED) package, varied types of fillers were investigated. These fillers included non-functionalized multiwalled carbon nanotubes (MWCNTs), functionalized MWCNTs, micro-SiC particles and the composite of functionalized MWCNTs and micro-SiC particles. Forward voltages at test conditions, junction temperatures, luminous fluxes and operation current-forward voltage (I-V) relation of HB-LEDs were measured or determined for varied combination and contents of fillers in the epoxy. The experimental results showed the epoxy with the composite of 30wt% of SiC and 5wt% of MWCNTs had the best thermal properties. Comparing to commercial epoxy, under the operation of injection current of 350 mA, the MWCNT/SiC/epoxy could decrease junction temperature from 123 to 93 °C and thermal resistance from 81 to 65°C/W.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)