The thermal management has become increasingly important when comes to device applications using ultra high power light emitting diodes (UHPLEDs). To thermally manage the devices in a most effective fashion, we report a novel packaging technique in which a copper electroplating process is directly applied over the red, green, and blue LED chips. With the copper-encapsulated layer, the operation current subsequently administered to these LED chips can be increased easily from a conventional 350 mA to more than 1050 mA stable at room temperature. This process can be well adapted to AlInGaP-based red LED when its working current can be driven all the way up to 1650mA. At 350 mA, the relative luminous intensity of these specially packaged red, green, and blue LEDs (RGB LEDs) clearly demonstrate a corresponding enhancement of 53%, 69%, and 23% when compared to those of conventionally packaged LEDs.Furthermore, as the injection current of these LED chips increases to 850mA, the respective improvement in relative luminous intensity of these RGB LEDs chips becomes 4310%, 83%, and 18%, when compared to those of the conventional packaged devices. IntroductionLight emitting diodes (LEDs) are potential candidate for the applications of general lighting, backlight of liquid crystal display (LCD), and headlamp of vehicle. However, lack of good thermal management for the ultra high power LEDs which work over than IA has obstructed the revolution in lighting market. Heat in LEDs was major caused by the high junction temperature, and can be improved by increasing external quantum efficiency. Now some applications are not contented with the speed of improvement in external quantum efficiency, therefore thermal management has ramped to be a key issue. In a LEDs module, many interfaces in the path of thermal dissipation are critical to limit the capacity of heat conduction [1], and the interface between LED chip and lead frame is the most important bottleneck of heat conduction. Many mediums were used to attach LED chip on lead frame including resin with/without silver particle, tin solder, and indium. The thermal conductivity of epoxy is general less

In GaN-based light-emitting diodes (LEDs), using gold-based metals to serve as electrodes, light absorption is a problem that severely restricts the light extraction in LEDs. This study demonstrates the GaN-based LEDs with high reflectivity metals (Ag/Pt) onto an n-type GaN surface and transparent contact layer (indium-tin-oxide), to serve as the n-type electrode and the p-type electrode, respectively. By replacing Cr/Au with Ag/Pt to serve as electrodes of LEDs, the light output power of the LEDs was increased by 15.7%, thereby significantly reducing the manufacturing cost of LEDs.Index Terms-GaN-based light-emitting diodes (LEDs), high reflectivity electrodes, light absorption.

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