High-Power AlGaInP Light-Emitting Diodes with Patterned Copper Substrates by Electroplating

We have developed a large-area (1.2 mm ×1.2 mm) chip structure for high-power AlGaInP/mirror/Cu light-emitting diodes (LEDs) to improve both the heat dissipation and substrate light-absorbing problems encountered in conventional AlGaInP/GaAs LED samples. Especially, this LED samples can be accomplished without additional dicing process. It was found that the peak-spectral wavelength of the AlGaInP LED with an electroplated copper substrate exhibited only about 3 nm shift at 400 mA, corresponding to a ∼30°C rising in the junction temperature. However, the junction temperature increased to 110°C easily for the AlGaInP/GaAs LED sample under a current injection of 400 mA. This indicates that the joule heating is less pronounced for the high-power AlGaInP/mirror/Cu LED sample where the metallic substrate provides a good heat sink.