在铝基板上贴片了不同间距的四颗芯片级封装发光二级管(CSP-LED)模组, 测试了不同贴片间距CSP-LED模组的EL光谱、流明效率、光通量、相关色温等光电参数。结果显示, 在小电流(20~400 mA)下, 随着注入电流的增大, 不同排布间距的蓝、白光样品的光电性能基本呈现相同的变化规律,即光通量、光功率呈线性增长, 光效基本保持稳定; 在大电流(1~1.5 A)下, 随着芯片间排布间距减小, EL光谱积分强度降低, 色温升高, 红色比下降, 排布间距为0.2 mm的光通量衰减了84.58%, 相比之下排布间距为3 mm和5 mm的光通量衰减明显减缓, 分别为8.96%和3.58%, 这些现象与禁带宽度、热应力、非辐射复合等因素有关。结果表明, CSP白光LED光通量衰减主要是荧光粉退化导致的, 考虑到实际生产成本问题, 排布间距为3 mm时, 有利于热量散出, 进而提高LED光电性能特性及其自身的使用寿命。

Four chip-scale packaged light-emitting diode (CSP-LED) modules with different pitches were mounted on an aluminum substrate. The EL spectrum, lumen efficiency, luminous flux, correlated color temperature and other photoelectric parameters of CSP-LED modules with different patch pitches are measured. The results show that under low current (20~400 mA), with the increase of the injection current, the photoelectric properties of blue and white light samples with different arrangement intervals basically show the same change law. It is like that the luminous flux and optical power increase linearly, and the optical efficiency is basically stable. Under high current (1~1.5 A), as the arrangement spacing between chips decreases, the integrated intensity of the EL spectrum decreases, the color temperature increases, the red ratio decreases, and the luminous flux with an arrangement spacing of 0.2 mm attenuated by 84.58%. In contrast, the attenuation of luminous flux at 3 mm and 5 mm arrangement spacing is significantly slowed down, 8.96% and 3.58%, respectively. These phenomena are related to factors such as the forbidden band width, thermal stress, and non-radiative recombination. The results show that the main reason for the attenuation of CSP white LED light flux is the degradation of phosphors. Considering the actual production cost, when the spacing is 3 mm, it is conducive to heat dissipation, thereby improving the LED photoelectric performance characteristics and its own service life.