LED器件点胶和喷涂工艺胶面温度研究

研究了LED点胶工艺和荧光粉喷涂两种工艺的LED器件产品在不同的输入电流下,LED器件发光面胶体表面温度的变化情况。实验样品采用28 mm×28 mm大小镜面铝基板,发光面直径为22 mm,25 mil×36 mil LED蓝光芯片,芯片电压为3~3.1V,芯片波长为455~457.5 nm,Po>240 mW。器件内部电路结构为18并18串,色温为2700 K,显色指数Ra>80。采用热电偶探头测试LED器件发光区域胶体表面温度,热电偶探头的位置在发光面的中心,整个实验过程是在一个30 cm×30 cm×10 cm的散热器上进行,在室温25℃的环境下,器件的输入电流为100~1000 mA,记录两种工艺的LED器件产品发光区域胶体表面的温度变化。实验结果表明,采用荧光粉喷涂工艺可以有效降低LED器件发光区域胶体表面的温度,且随着功率的增加,降温效果更加显著。LED器件发光区域表面温度降低,意味着LED芯片的结温也会随之降低,可提高LED器件的可靠性。

Study on Surface Temperature of Dispensing and Phosphor Spraying for LED Devices

In this paper,the temperature change of surface of LED device under different input current was studied.The experimental sample was made of 28 mm×28 mm mirror aluminum substrate,with a luminous surface diameter of 22 mm and 25 mil×36 mil LED blue chip.Chip voltage is 3~3.1V,chip wavelength is 455~457.5 nm,Po>240 mW.The internal circuit structure of the device was 18 parallel and 18 series,and the color temperature was 2700 K with Ra>80.A thermocouple probe was used to test the surface temperature of the surface of LED device,the location of the thermocouple probe in the center of the light-emitting surface,the whole experiment process is conducted on a 30 cm×30 cm×10 cm radiator,at room temperature 25℃environment,input current of the device from 100 mA to 1000 mA,Recording the temperature variation of the surface of the LED device of the two processes.Experimental results show that the application of phosphor spraying technology can effectively reduce the temperature of the surface in the luminous region of LED devices,and the effect is more remarkable with the increase of power.The lower surface temperature in the light-emitting region of LED device means that the junction temperature of LED chip will decrease accordingly,which can improve the reliability of LED device.