Research Of High Power LED Thermal Management Based On Ionic Wind

In recent years,The international community has been paying more attention to“low-carbon,energy saving,and environmentally friendly”,especially in manufacturing area.Therefore,solid LEDs which act as a new type of “green light source” are widely used in the field of lighting.However,LEDs have special light-emitting principle and small packaging structure,which lead to high junction temperature and severe thermal management issues.Especially for high power LEDs,the high driven current will heat the whole chip in a short time.Thus,the heat dissipation problem has hindered the applications of high power LED.With the continuous breakthrough of manufacturing process and packaging technology,the internal thermal resistance has been significantly reduced.Now,we need to propose an efficient external cooling solution to improve the heat dissipation.In this study,the disadvantages of the traditional cooling methods were discussed,and an ionic wind cooling scheme based on the corona discharge principle was proposed.The ionic wind cooling device was designed with adjustable structure and a test system bench was set up.On the one hand,the influencing factors of corona discharge were proposed through the study of volt-ampere characteristics,and the electrical properties of the discharge process were also discussed,thus,the methods to improve both ionic wind speed and volume were found.On the other hand,LED pin temperature,chip junction temperature,and the system thermal resistance,etc.were taken as the criteria to judge the heat dissipation effect of the cooling device on the high power LEDs.When building the cooling system for high power LED in this study,several needle array arrangement schemes were proposed according to the structure and characteristics of the heating device.The cooling device in this research was proved to be effective,and the ionic wind enhanced the thermal coefficient between the discharging electrodes.LED chip pin temperature kept at 48? when LED and cooling system start at the same time,because the system thermal resistance significantly reduced in the role of ionic wind.It was alsoconcluded that negative polarity and needle electrode on emitting electrodes were easier for generator to discharge,the discharging process was more stable and the voltage range was wider,so negative polarity and needle electrode were more suitable to act as the configuration of corona wind generator.needle electrode in “--” array arrangement came to be better in heat dissipation than other given arrangement.