There are many reasons that cause the full-color LED display to lose control, the most important of which is "LED failure".
The main reasons leading to the failure of the full-color LED display can be divided into two aspects: one is the poor quality of the full-color LED display itself; the other is the improper use. On this basis, we summarized the corresponding relationship between the failure mode of the full-color LED display and the above two factors.
Full color LED display
Many of the above-mentioned faults of the full-color LED display are often not found in the routine inspection and test of the full-color LED display. Except for improper use such as electrostatic discharge, high current (resulting in excessive junction temperature), external force, etc., many full-color LED display failures occur under harsh environments such as high temperature, low temperature, and rapid temperature changes. The thermal expansion coefficients of epoxy resin, bracket, guide wire, die-bonding glue, PPA cup body and other materials are different, and the internal stress caused is also different, so the quality inspection of full-color LED display is very complicated.
In addition, for full-color LED displays, electrostatic discharge is the biggest cause of its failure. Because the reasons for the failure of the full-color LED display are very complicated, equipment, tools, utensils and the human body may introduce static electricity and discharge it, and this static discharge is only a few thousand volts, several thousand volts and nanoseconds. time. The blue-green pipeline failures of the displays produced, installed and used by our company are often caused by the breakdown of the LED-PN junction by electrostatic discharge.
ISA has strictly regulated the standard electrostatic discharge mode, which is mainly divided into human body discharge mode (HBM) and mechanical discharge mode (MM). In China, the electrostatic discharge sensitivity (ESDS) is divided into three levels of the human body: level 1 01999V; level 2 20003999V; level 3 above 4000V.
Generally, the sensitivity of a full-color LED display to electrostatic discharge is a few hundreds to tens of thousands of volts in the human body mode, and only tens to 500 volts in the machine mode. Due to the complicated production process, the full-color LED display has a weak antistatic ability. Therefore, the electrostatic sensitivity of the full-color LED display should be level 2 or higher (human body), and the electrostatic protection must run through the entire production process.
