High-power violet light emitting diodes with electroplating copper heat spreader

Abstract

Using self-alignment photolithography and copper electroforming techniques, we have developed a size of 1mm×1mm high power GaN-based violet LED embedded in a reflective cup-shaped copper heat spreader. The packaged LED chip sample with copper heat spreader driven at 1 A current yield the light output power of 310 mW, about 1.55 times to the conventional LED. Moreover, the power efficiency is remarkably increased from 4.21% to 6.61% at the same driven current. These results indicate that the novel heat dissipation, a direct Cu heat spreader by a metal connection to the device, did efficiently extract the heat from the chip. The result exhibit a new solution to thermal management of high power GaN-based violet LED samples.