根据板上芯片(COB)集成封装的结构特点, 同时考虑反光杯结构和荧光粉涂敷方式, 分析了影响COB封装的发光二极管(LED)发光性能的主要因素。针对反光杯结构的关键要素: 反光杯形状、反光杯深度、反光杯角度, 优化设计了LED光学结构。通过改变TracePro软件中反光杯的相关参数, 模拟了不同LED的光强分布及发光效率, 探讨了提高COB封装的白光LED发光效能的途径。最后, 在4 mA和12 mA电流下进行了传统荧光粉涂敷方式及荧光粉远离芯片涂敷方式的对照实验。仿真及实验结果表明: 采用圆锥形反光杯, 反光杯深度在一定范围内略大, 且反光杯角度设为30°时, LED发光性能较为优异。与传统封装方法相比, 采用荧光粉远离芯片的封装方法可使发光效率提高5%左右。 得到的结果对LED封装制造过程有指导意义。

According to the characteristics of Chip-on-board (COB) packaging structure and considering the reflective cup structure and fluorescent powder coating methods, the main factors impacting the light emitting properties of a COB packaged Light Emitting Diode(LED) were analyzed. On the basis of the several key elements of reflective cup structure, indluding its shape, depth, and angle, this paper optimized the design of LED optical structure. By changing the relevant parameters of reflective cup in TracePro software, the light intensity distributions and output efficiencies of different LEDs were simulated, and the approach to improve the light luminescence properties of a COB packaged white LED was discussed. Finally, the contrast experiments on a traditional phosphor coating method and a coating method with phosphors away from the LED chip were performed under drive currents of 4 mA and 12 mA, respectively. The simulation and experimental results show that the luminous performance is more excellent in the reflective cup with a conical shape , a bigger depth in a certain range and a angle of 30 °. As compared with traditional packaging method, the coating method with phosphors away from the LED chip can improve the luminous efficiency by more than 5%. It has certain guiding significance for the LED packaging manufacturing process.