Analysis on heat dissipation of LED automobile headlamp

2020-12-09 11:17:29

For a long time, the LED heat problem has been troubling the whole industry, and in the face of a high growth car headlight market, but do not want to miss. Next, we will discuss how to overcome the problem of heat dissipation in the small space of the headlight, and then achieve the national standard of 50 ℃ ambient temperature, the higher junction temperature can not exceed 80 ℃. At present, the design power of low beam and high beam light is 40 ~ 60W, while the power of automobile is more than 80W. In addition, the width indicator lamp, direction light and so on, it is not easy to generate heat energy under very high power. It is difficult for engineers to solve the heat dissipation problem. Heat and space are inseparable, in the condition of large space, you can choose a cheaper cooling solution. For example, street lamps can be easily solved by increasing the heat dissipation aluminum seat. However, if the mobile phone is enlarged, no one will ask for it. If it is not solved, it will be like taking a piece of hot potato. Therefore, the artificial graphite heat sink is used to disperse the heat to form a heat source, and the surrounding area is homogenized. With the concept of space, we can understand the heat source and the required upper limit temperature. The heat source is to transfer the temperature to the surface and then to the gas through the solid heat conduction. The gas convection is slow and passive, so it is very important to solve the whole packaging material and heat source first. It is well known that led chips are converted from electricity to light, and the efficiency is only 30% in general, and the remaining 70% are turned into heat. If the heat is not released in time, the light efficiency will be reduced. The CSP structure adopted by automobile headlamp is related to the following aspects: first, how much heat is generated by the number of watts; second, the thermal conductivity of upper and lower materials, which affects the overall temperature uniformity; third, the thickness of these materials. Table 1 shows the thermal conductivity of various materials. With these concepts, we can start to solve the problem of heat dissipation.