A kind of chips on board (COB) package of light emitting diode (LED) light source is designed and produced. By reducing the current density and using the mirror aluminum substrate with high reflectivity to improve the luminous efficiency. Meanwhile, three kinds of red phosphors with peak wavelength of 630 nm, 631 nm and 639 nm are added on the basis of yellow-green phosphors, which increase within the range of red light LED spectrum composition, improve the LED color rendering index. The measurement results show that under 500 mA forward current, the luminous flux density of LED on the luminous surface with an area of 227 mm2 reaches 14.4 lm/mm2, the luminous efficiency reaches 175.5 lm/W, and the color rendering index reaches 89.3. It is found in the process of measuring the LED color temperature changes slightly with the current change, and by calculating that the proportion of blue photons in the LED spectrum is increasing gradually, the cause of this phenomenon is the phosphor excitation efficiency is saturation when the optical power density is high, which is influenced in two aspects: the proportion of photons absorbed by phosphor or the phosphor excitation efficiency decreases, the two factors together or separately cause the phosphor excitation saturation effect.

中文翻译：

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板载发光二极管高光效、高显色指数芯片及荧光粉激发激发饱和效应研究

设计并生产了一种发光二极管（LED）光源的板上芯片（COB）封装。通过降低电流密度，使用反射率高的镜面铝基板来提高发光效率。同时，在黄绿色荧光粉的基础上加入了峰值波长为630nm、631nm和639nm的三种红色荧光粉，在红光LED光谱组成范围内增加，提高LED显色指数。测量结果表明，在500 mA正向电流下，LED在面积为227 mm2发光面上的光通量密度达到14.4 lm/mm2，发光效率达到175.5 lm/W，显色指数达到89.3。在测量过程中发现LED色温随着电流的变化略有变化，