反射杯影响COB封装LED的光、热性能的模拟仿真与实验研究

Simulation and experimental study on the optical and thermal properties of COB-Packaged LED with reflector cup

通过应用多物理多尺度有限元软件COMSOL及光学追踪设计软件Tracepro分别模拟仿真了不同发射杯结构COB封装的LED芯片的散热和出光性能,并对结温和光效等模拟计算结果进行了实验验证。结果表明:COB封装散热性能优于SMT封装,去掉散热基板上的绝缘层会显著降低结温和热阻;通过优化COB封装情况下的反射杯结构,发现:当反射杯杯口、杯底直径、深度分别为3.0mm、1.6mm、0.6mm时,出光效率为48.36%,比无反射杯的光效提高20%,辐照强度增加1倍;铝基板上封装的LED,模拟与实测结温之间的相对误差约为4.42%,表明模拟与实验结果一致。出于经济和成本考虑,建议优选带反射杯的铝基板进行COB封装。

The heat dissipation and light output performance of COB-packaged LED chips with different emitter cup structures were simulated by using COMSOL,a multi-physical and multi-scale finite element software,and Tracepro,an optical tracking design software,respectively.The simulation results of junction temperature and light efficiency were experimentally verified.The results show that the heat dissipation performance of COB package is better than that of SMT package,and the junction temperature and thermal resistance can be significantly reduced by removing the insulation layer on the heat dissipation substrate.By optimizing the structure of the reflector cup under COB package,it is found that when the diameter of mouth and bottom,and depth of the reflector cup are respectively 3.0 mm,1.6 mm and 0.6 mm,the output light efficiency of LED is 48.36%,20%higher than that of the non-reflector cup,and the irradiation intensity is doubled.The relative error between the simulation and measured junction temperature of Al-MPCB packaged LED is about 4.42%,indicating that the simulation results are in agreement with the experimental ones.For economic and cost considerations,it is suggested that Al reflector cup is preferred for COB packaging.