A high power LED device with chips directly mounted on heat pipes

A novel columnar heat pipe (CHP) leadframe for high power LED device was developed. 42 high power LED chips were mounted on its surface directly. The thermal performance, luminous and chromaticity of the CHP leadframe base LED device are tested and discussed experimentally. The obtained results show that the thermal resistances Rl-s (from the leadframe to the heat sink) and Rj-a (from the LED chip to the ambient) of the CHP leadframe are 0.23 °C/W and 1.65 °C/W at 2800 mA, respectively. The luminous efficacy of the CHP leadframe LED device is 66.23 lm/W at 2800 mA. It is 19.2% higher than the conventional copper leadframe LED device. The correlated color temperature (CCT) shift value of the CHP leadframe is 381 K and it is lower than that of the copper leadframe by 23.5%. The discussed results show that the CHP leadframe has an outstanding performance for high power LED lighting.