As LED technology has been widely used as a new generation of lighting technology in recent years, LED lights are currently applied in most lighting places, such as the LED flood light, the LED wall washer light, the LED tunnel light, etc. In this process, the power of LED lights will gradually increase to meet the lighting needs. Therefore, more people pay attention to the heat dissipation problem of LED lights. The light decay and service life of LED lights are directly related to the junction temperature. If the heat dissipation is not good, the junction temperature is high, which will shorten the service life.
The reason is that the added electric energy is not all converted into light energy, but part of it is converted into heat energy. Currently, the luminous efficiency of LED outdoor linear light is only 100lm/W, and the electro-optical conversion efficiency is only about 20-30%. In other words, about 70% of the electrical energy will be turned into heat. To be specific, the LED junction temperature is caused by two factors.
1. When the internal quantum efficiency is not high or when electrons and holes are recombined, not all photons can be produced. It is usually called "current leakage," which can reduce the recombination rate of carriers in the PN region. This part of power equals the leakage current times the voltage, which is converted into heat energy. However, this part does not account for the main component since the internal photon efficiency is close to 90%.
2. The photons generated inside LED lights cannot all be emitted to the outside of the chip and converted into heat. This part is important since the efficiency of external quantum is only about 30%, and most of them are converted into heat.
According to the literal meaning of LED linear floodlight, it can project light and shadow. Since the floodlight line is relatively dense and the brightness of the floodlight is higher than that of the surrounding environment, the LED floodlight is also called the LED projection light or the LED spotlight. The decorative LED flood lights use a built-in microchip to control the range and intensity of the light.
According to the power, LED linear flood lights can be divided into two categories. One is a combination of power chips, which has relatively stable performance and is more suitable for small-scale illumination. The other type uses a single high-power chip with a large structure and can be used for large-area and long-distance light illumination.