The heat sink structure is simple for heat dissipation of COB-based semiconductor illumination sources

The CFD simulation does not consider the contact thermal resistance between the components of the heat sink; there is an error in the assembly process of the heat sink and the measurement accuracy of the thermocouple in the experiment. It can be said that the experimental data confirms the correctness of the simulation results within the error range of simulation and experiment. Therefore, experiments and theories have shown that the use of drainage holes has a significant improvement in the performance of the heat sink based on the chimney effect, that is, the heat dissipation is further reduced under the condition that the COBLED operating temperature has little influence (about 2 ° C). The weight of the radiator (the weight of the radiator example is reduced from 1157g to 1010g) improves the overall performance of the radiator.

For the street lamp using COB-based semiconductor illumination source, the COBLED's illumination axis is 60° from the gravity direction [3], and the chimney-based finned-heatsink structure with drain holes is proposed and calculated by using Icepak. The fluid mechanics simulation software studied in detail the influence of the shape, size and distribution of the drainage holes on the quality factor Q of the radiator. The simulation results show that for a COBLED with a surface area of 4cm2 and a heat of 50W, at a maximum temperature of less than 52 °C, two chiseled holes with an area of 15 cm2 and a central symmetry of the light source will be formed on the heat conducting plate. The weight of the radiator is further reduced by 15%.

The simulation results were verified by experiments. When the COBLED injection power is 80W, the weight of the heat sink is reduced from 1157g to 1010g compared with the traditional chimney-based heat sink. The COBLED substrate is relative to the ambient air. The temperature rise increased from 35 ° C to 37 ° C, which is basically consistent with the simulation results. The heat sink designed in this paper is simple in structure, light in weight and low in thermal resistance, and can be used for heat dissipation of COB-based semiconductor illumination sources.