摘要
基于水溶性感光胶的自光LEDs平面涂层技术，在蓝光LED芯片表面上得到了可控的荧光粉层．采用降低粉浆中ADC的浓度和提高荧光粉的含量两种措施，减少Cr^3＋在433．6和620nm两处吸收对器件出光效率的影响；新配制的粉浆在暗室中静置3～5h，既可以提高器件的出光效率同时又避免了暗反应带来的影响；在蓝光LED表面上得到粉层后，再涂覆硅胶层，由于硅胶的折射率与粉层的更接近，不但使出光色调偏向蓝光区域而且有更多光子出射，光通量由未加硅胶层时的44．8～59lm提高到了79．4～84．9lm．
The slurry method based on water soluble PVA is discussed. A controlled phosphor layer is obtained by the slurry method on the surface of blue LED chips. Due to the absorption of Cr^3＋ , the luminous intensity of white LEDs can be improved by decreasing the concentration of ADC or increasing the concentration of phosphor in the slurry. The stand-time of slurry for 3～5h was optimized in a darkroom. The hue of output light moved to the blue-light zone and the luminous flux increased from 44. 8～59 lm to 79.4～84. 9 lm after the silica gel was coated on the LED coated phosphor particles.
基金
国家高技术研究发展计划资助项目(批准号:2006AA03A116)~~
关键词
白光LEDs
粉浆
出光效率
封装
white LEDs
slurry
luminous performance
packaging
