led life determines the life of display screen, but it is not to say that led life is equal to display life. Because the display screen is not working at full load all the time, the life of the display screen should be 6-10 times longer than that of the LED under the normal condition of playing video programs.
The internal factors include the performance of peripheral components, the performance of LED light-emitting devices, the anti fatigue performance of products; the internal factors include the working environment of LED display screen and so on.
(1) influence of peripheral components
In addition to LED light-emitting devices, LED display screen also uses many other peripheral components, including circuit board, plastic shell, switching power supply, connector, case, etc. if any component fails, the life of the display screen may be reduced. Therefore, the long life of the display screen is determined by the life of the key component with short life. For example, led, switching power supply and metal shell are selected according to the 8-year standard, while the protective process performance of the circuit board can only support its work for 3 years. After 3 years, it will be damaged due to corrosion, so we can only get a 3-year-old display screen.
(2) the influence of LED light-emitting device performance
LED light-emitting device is the key part of display screen, and also related to life. For LED, the main indicators are as follows: attenuation characteristics, water vapor permeability characteristics, anti ultraviolet performance. If the LED display manufacturer fails to evaluate the performance of LED devices, it will be applied to the display screen, which will lead to a large number of quality accidents and seriously affect the life of LED display screen.
(3) the influence of anti fatigue performance of the product
The anti fatigue performance of LED display depends on the production process. It is difficult to guarantee the anti fatigue performance of the module produced by the poor three prevention treatment process. When the temperature and humidity change, cracks will appear on the protection surface of the circuit board, leading to the decline of the protection performance.
Therefore, the production process of LED display screen is also the key factor to determine the display life. The production process involved in the production of display screen includes: storage and pretreatment process of components, furnace welding process, three prevention treatment process, waterproof sealing process, etc. The effectiveness of the process is related to material selection and proportioning, parameter control and operator quality. For most LED display manufacturers, the accumulation of experience is very important. A factory with many years of experience will be more effective in controlling the production process.
(4) impact of working environment
Due to different uses, the working conditions of display screen are very different. From the environmental point of view, the indoor temperature difference is small, without the influence of rain, snow and ultraviolet; the outdoor temperature difference can reach 70 degrees, plus wind, sun and rain. Harsh environment will aggravate the aging of display screen, and the working environment is an important factor affecting the life of display screen.
The life of LED display screen is determined by many factors, but the end of life caused by many factors can be continuously extended by replacing parts (such as switching power supply). The LED is not likely to be replaced in large quantities. Therefore, once the life of LED is over, it means the life of display screen will be terminated.
When the LED works under the condition of small current, the life of the LED can be longer. Therefore, the lifetime of the display screen with this brand of LED can reach about 50000 hours.
How to make LED life longer? In general, we can start from two aspects of device manufacturing and device application. In terms of device manufacturing, LED life can be prolonged by choosing epitaxial materials, increasing chip area and reducing current density, equalizing current density, reducing thermal resistance, selecting packaging materials with excellent performance and strong UV resistance.
From the aspect of device application, it can extend the service life of led by taking heat dissipation as a central work from module design to engineering implementation and even future system maintenance; reducing the working current of LED; correctly configuring led to make all primary color LED decay synchronously.
Whether the LED lamp is stable, the quality is good or not and the heat dissipation of the lamp body is very important. At present, the heat dissipation of high brightness LED full-color screen is usually natural heat dissipation, and the effect is not ideal. If the heat dissipation is not ideal, the life of the lamp itself will also be affected.