LED display pixels of failure, the primary reason is that the elements of the LED and LED failure cause and can be divided into two aspects: 1.
The LED itself quality Clinton;
Using the method.
The failure of many LED usually in LED inspection cannot be found in the test of practice.
But by electrostatic discharge, high current (
Form the junction temperature is too high)
And external strength, improper use, many LED failure is the rapid change in the high temperature, low temperature, temperature or other harsh conditions, because the LED chip, epoxy resin, stents, fuses, solid crystal glue, PPA in the cup body materials such as thermal expansion coefficient, the difference between a trigger its internal stress is not the same.
Leds quality detection is a very complicated work.
Moreover, about GaN LED, electrostatic discharge is the biggest cause of failure.
Failure mechanism of electrostatic discharge in the LED is very complex, the vessels equipment, things, and have to human body with static and the discharge, the static electricity is less several hundred volts, high tens of thousands of volts, discharge time in nanoseconds.
We produce on display, device, present in the process of using blue green tube failure, and is often LED -
PN junction is electrostatic discharge breakdown may go.
The world association of electrostatic tough rules a standard form of electrostatic discharge, first divided into human body discharge form (
And machine discharge form (
Our sensitivity to equipment of electrostatic discharge (
Divided into three levels (
The human body form)
: level 1 to 0 ~ 1999 v;
Level 2 is 2000 ~ 3999 v.
Level 3 for more than 4000 v.
Often LED the electrostatic discharge sensitivity in human form between a few hundred volts and tens of thousands of volts, and under the machine form as long as dozens of v to five hundred v or so.
LED display's mad because produce process, electrostatic discharge small-scale operations, therefore, LED electrostatic discharge sensitivity should choose grade 2 or more as appropriate (
The human body form)
Through producing process, and static electricity protection necessary.