Experimental study on the thermal performance of 395 nm ultraviolet light-emitting diodes fabricated with eutectic flip-chip package

In this paper, the characteristics of ultraviolet light-emitting diodes (UV-LEDs) operated at 395 nm, such as the improvement of light output power and thermal resistance control were investigated. The advanced package method fabricated with eutectic flip-chip package and silicone bonding quartz lenses was presented to meet the optical and thermal demands of UV-LEDs. The optical and thermal performance of different UV-LED devices was evaluated and compared by measuring the light output power, thermal resistance and junction temperature. It was found that the bonding thermal resistance of eutectic device with silicone bonding quartz lens was lower than soldering device by 4.8 K/W, contributing a junction temperature reduction by 17.8 °C at 800 mA. It was also obtained that the light output power of eutectic device with silicone bonding quartz lens dramatically enhance up to 73.4% at 1500 mA, compared with the soldering device. It is believed that the results will potentially provide guidance in the research and application of flip-chip 395 nm UV-LEDs and make positive contribution to energy conversion and management.