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Mobile WebSiteAnalysis of the current status of vehicle lamp system reliability
Since the birth of white LEDs, LED lamps have received much attention from the industry. In recent years, with the rapid development of LEDs, the coverage from signal-based automotive lamps to lighting-type LED lamps has become higher and higher. The trend of explosive development, the diversification of optical implementation, the intelligent control method, the complication of modeling functions, and the hybrid application of semiconductor lasers, OLEDs, etc., have higher and higher requirements for the reliability of the entire LED system.
The LED headlight system is a complex system involving a series of disciplines such as optics, electronics, structure, and thermal management. The following figure shows the LED system and some common reliability issues.
LED thermal management technology status
Thermal management has been studied in the traditional automotive industry and the LED industry. The most commonly used LED cooling methods in the lamp system are passive cooling of the heat sink and active cooling of the fan. Water cooling and heat pipe technology in the field of electronic computers have no mature practical cases for reasons of reliability and cost.
However, most of the existing thermal management technology research is generally concentrated on the LED subsystem. There is even a general view that LED is a cold light source. As long as the heat management of the LED component itself is solved, the reliability document of the LED lamp can be solved, and the life can exceed the life of the vehicle.
Thermal analysis is absolutely essential in all aspects of product development (components, subsystems, and the entire system). However, good thermal analysis results are only possible if the thermal models at all levels are good.
The overall system level thermal design and analysis needs to take into account more factors. Under the correct conditions of the model, it is necessary to comprehensively consider the direction of the airflow, the design of the optical surface, the structure of the luminaire, and the shape of the radiator. This puts higher requirements on system integration capabilities and team technical cooperation capabilities.
LED lamp anti-fog technology status
In the modern lamp manufacturing industry, especially in the LED lamp system, the design, manufacture and process are becoming more and more complex, and the quality of a large number of advanced technology lamps is perfected. However, the fogging of the lights is still a problem that affects the reliability of the lights. The water vapor caused by a series of changes in the temperature and humidity of the headlights is condensed on the inner surface of the lens of the lamp, which not only affects the appearance, but also greatly reduces the lighting effect and affects the driving safety. At the same time, it causes a series of reliability problems such as material corrosion and aging deformation. Since the overall heat of LED lamps is lower than that of conventional halogen lamps, fogging is particularly noticeable.
Because fog is a difficult physical phenomenon, there are two main problems in the industry: 1 is the area where the fog is generated, and 2 is the time from fogging to complete dissipation.
At present, there are two ways to alleviate the fogging of LED lights: 1. The interior of the lamp is coated with anti-fog coating. 2. Add a desiccant to the lamp.
Nowadays, with the development of CFD technology, on the basis of thermal analysis, we began to pay attention to the air flow field, comprehensive analysis of temperature field, combined with product system adjustment, to minimize the possibility of fog condensation from the design source.
