Thermal analysis of COB array soldered on heat sink

In this paper, the finite element method (FEM) and experiment were adopted to evaluate the thermal performance of a multi-chip COB LED lamp based on the cold spray technology. The results show that the junction temperature can be limited under 110 °C. Compared to an aluminum-substrate LED module pressed on the heat sink, the soldering structure of a copper-substrate LED can reduce the junction temperature. The junction temperature of the LED module soldered on the heat sink is only 97.3 °C, while one of the pressing structures is 103.5 °C. It is further found that the chip gaps and the thickness of the copper-circuit layer have significant effect on the heat spread. Increasing the chip gaps and the thickness of the copper-circuit layer can effectively reduce the junction temperature and improve the LED lamp's thermal performance.