because Full color LED displayIt is composed of tens of thousands or even hundreds of thousands of pixels composed of red, green and blue LEDs. The failure of any color LED will affect the overall visual effect of the display screen. So choosing a good LED is a very important thing.
　　
LED is the most critical component of full-color LED display screen, which is equivalent to the CPU of computer The selection of LED has determined the quality of the whole display screen by more than 50%. If the LED is not selected well, no matter how good other parts of the full-color LED display can make up for the quality defects of the display. Generally speaking, according to industry experience, the failure rate of the LED display screen should not be higher than 3 / 10000 (referring to the failure caused by the LED device itself) 72 hours before shipment.
　　
Led failure generally includes the following three categories: short circuit (leakage), open circuit and dim light. Short circuit (leakage) is generally caused by the change of LED chip performance caused by too large impulse current in the module circuit and the increase of chip leakage current; Open circuit may cause led chip breakdown due to static electricity or other reasons; Generally, the dark light is due to the improper use of LED, resulting in water vapor in the colloid, which affects the optical effect of LED.
　　
Pay attention to the detail control of the reasonable use of LED in production: pay attention to the reasonable control of the feeding and use of materials, and do moisture-proof process for expired materials; Pay attention to the strict control of anti-static measures. The display assembly factory should have good anti-static measures. Special anti-static ground, anti-static floor, anti-static soldering iron, anti-static table mat, anti-static ring, anti-static clothing, humidity control, equipment grounding (especially foot cutting machine) are basic requirements, and should be tested regularly with an electrostatic instrument; The temperature and furnace passing time of wave front welding must be strictly controlled.
　　
The temperature parameters of wave soldering machine should be tested regularly: This is determined by the characteristics of LED. Overheated or fluctuating temperature will directly damage led or cause hidden dangers of LED quality, especially for round and Oval LED with small size such as 3mm; When the LED of full-color LED display screen is not lit, there is often more than 50% probability that it is caused by various types of faulty soldering, such as LED pin faulty soldering, IC pin faulty soldering, pin and busbar faulty soldering, etc. The improvement of these problems needs to be solved by strictly improving the process and strengthening the quality inspection.