Study on the fabrication and thermal performance of aluminum substrate for high power LED

Accelerated aging tests at 1A were carried out on a new type of integrated high-power white GaN-based light-emitting diodes which we encapsulated the LED chip to the aluminum plate directly.Then the electrical,luminous and spectral characteristics were researched to analyse the failure mechanism of the device including the LED chips and phosphor.The electrical characteristics demonstrated that both the series resistance and thermionic emission current increase after aging.Luminous flux curve shows that the lower electron mobility,the higher the recombination rate,so the decay rate of the LED is slow when the drive current is low.Spectra and color temperature curves show that the phosphor degradated fast in initial stage of aging,well blue chip attenuation was dominant after a certain period of time.