针对目前LED灯具在照明方面显色性不足,以及传统LED点胶封装所存在的芯片发热导致荧光粉性能衰减、色温漂移、出光不均匀等问题,采用近年来新兴的远程荧光封装方式。用黄绿色YGG荧光粉和氮化物红色荧光粉,与硅胶制成远程荧光片封装成LED灯具。通过大量实验确定了黄绿粉、红粉与硅胶的最佳比例,制备了不同色温的LED灯具,并选择了色坐标,光效,显色指数,R9,色质指数,色温,全色域指数等参数对灯具进行了测试与分析,为优质LED照明提供了更客观地综合评价。实验结果表明红粉与黄绿粉的最佳比例为1:7.6,荧光粉总量与硅胶最佳比例为1:5,此时制成的白光LED灯具的色温为4 113 K,色坐标(x,y)为(0.375 4,0.373 1),光效为52.33 lm·w~(-1),色域度为0.981,显色指数高达96,其中R9为97。色质指数Qa值高达93,全色域指数为79。同时相较于传统封装而言,远程荧光封装的荧光板表面温度大大低于点胶封装荧光粉表面温度,可以有效地避免温度过高对LED产生的不良影响。
Focusing on the defects in the lighting color of LED lamps and the chip heat exists in the traditional LED package which caused phosphor performance degradation,color temperature drift and the uneven light,the remote phosphor package which is emerging in recent years is used in this paper.With yellow-green YGG phosphor and nitrogen red phosphors mixing with silica gel,the remote phosphor is made and then encapsulated as the LED lamps.A lot of experiments were made to determine the best ratio of yellow green phosphor,red phosphor and silica gel,LED lamps with different color temperature was prepared.The lamps were also tested and analyzed with some parameters such as e color coordinates,luminous efficiency,color rendering index(CRD,R9,color quality scale(CQS),color temperature,and the gamut area index(GAD,which provide a more objective and comprehensive evaluation to the high quality LED lighting.Experimental results show that the optimum ratio of red and yellow-green phosphor is 1:7.6,and total phosphor with silica gel is 1:5,at this time the white LED lighting color temperature is 4113 K,the color coordinate(x,y) is(0.375 4,0.373 1),luminous efficiency is 52.33 lm·w~(-1),color gamut is 0.981,color rendering index is up to 96,R9 is 97,color quality scale Qa is up to 93,and the gamut area index is 79.Compared with the traditional packaging,the surface temperature of the remote phosphor encapsulated fluorescent plate is much lower than that of adhesive dispensing encapsulation,which can effectively avoid the harmful effect caused by high temperature on the LED.