LED白光芯片的光色一致性及光谱优化设计方法研究

The Optical and Color Consistency and Optimal Design of Spectrum Power Distribution for LED White Chips

基于晶圆级芯片尺寸封装工艺的LED白光芯片具有高效节能、低热阻、小尺寸特点,被认为是未来制备高品质全光谱LED光源和模组的主要发展方向之一。针对自主研发的具有五面出光角度特点的LED白光芯片,采用光谱功率分布分析方法研究封装材料和尺寸对白光芯片光色一致性的影响。研究结果表明:(1)荧光层厚度和蓝光芯片输出功率对于白光芯片的颜色一致性影响显著,因此在LED白光芯片的量产过程中需要严格控制压膜工艺的精度和芯片来料的输出功率;(2)LED白光芯片的光效与理论光效和蓝光芯片转化效率的乘积呈线性关系,且相对色温越低,线性相关系数越小。最后,建立了一套高效实用的配粉设计流程,针对配粉实验提出了一种快速优化光谱设计方法来制定最佳荧光粉配比,为LED白光芯片工艺设计提供指导。

Based on the wafer level chip scale packaging technology,white light-emitting diode( LED)chip,with advantages on high efficacy,low thermal resistance and small size,has been considered as one of the most attractive technologies to manufacture the high quality full spectrum LED light sources and modules in the future. In this paper,the white LED chips with five illumination surfaces were prepared,then the influences of packaging materials and structure size on their optical and color consistency was investigated based on the spectrum power distribution analysis. The results indicate that:①the thickness ofphosphor layer and the power output(PO) of LED chip have significant influence on the color consistency of LED white chips. Therefore,the precision of molding process and consistency of LED blue chip' s PO should be strictly controlled during the manufacture;②the luminous efficacy of LED white chip was linearly dependent on its luminous efficacy of radiation( LER) and the photoelectric conversion efficiency of used LED blue chip(ΦB). The lower the correlated color temperature( CCT),the lower the coefficient of linear correlation. Finally, we developed an efficient and practical process to design phosphor mixture by optimizing the spectral power distribution,which can provide guidance on LED white chip design.