LED lighting fixture heat transfer basic path analysis (detailed)
Abstract: The influence of heat on LED is expounded, and the basic path of LED illumination heat transmission is analyzed. Then, various heat dissipation products and modules that may be used on LED lamps are introduced one by one. It provides first-hand learning materials for the LED industry, and also provides directions and references for thermal design for LED lighting engineers. Key words: junction temperature; heat transfer path; interface material; heat sink 1 Introduction In today's global energy shortage and environmental pollution, LED has a broad application space for its energy saving and environmental protection. Compared with traditional lighting fixtures, it also has the advantages of high brightness, low energy consumption, long life, good directionality and fast response. However, if the LED light source does not dissipate well, its lifetime and various performance parameters will also be affected. Therefore, understanding the causes and heat transfer paths of LED lamps, using reasonable heat transfer materials and scientific heat dissipation solutions, plays a very important role in promoting high-power LED lighting. 2, the impact of heat on the LED LED is a photoelectric device. In the working process, only 15% to 25% of the electrical energy is converted into light energy, and the rest of the electrical energy is almost converted into thermal energy, so that the temperature of the LED rises. In high-power LEDs, heat dissipation is a big problem. According to the current temperature resistance of the chip material, the junction temperature is usually not greater than 150oC, and the higher junction temperature has more adverse effects on the LED lamp. Experiments show that when the junction temperature of the LED rises, the output light intensity of the device will gradually decrease; and when the junction temperature decreases, the light output intensity will increase. In general, this change is reversible and recoverable. When the temperature returns to its original value, the light intensity will return to its original state. As shown in Figure 1: Figure 1 Effect of junction temperature on LED light output Nantong Boxin Electronic Technology Co., Ltd. , https://www.bosencontrols.com
2.1 The effect of junction temperature on LED light output