Degradation characteristics of blue GaN-LED chip related to packages

This paper reports the degradation characteristics of blue GaN-LED (Gallium Nitride-light emitting diode) chip related to various packages. Three types of package have been considered to investigate degradation characteristics in this study. One package is our proposed new concept of metal package by which we can estimate the lifetime of blue LED chip (chip size: 1mm × 1mm) with high accuracy. In the proposed package, components in conventional LED package which may obscure the degradation behaviour of LED chip itself were removed or replaced by other materials or components. And as a control group, two types of commercial packages were used (3W package and low power package). We investigated and analyzed the light-output degradation and changing of package materials of high-power blue LED chip packaged with these three types of package to aging time of 5,000 hours. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)