What Is The Harm Of Electrostatic To LED Chip?
In the LED industry, it seems that static electricity as the number one enemy of damaging LED. But is it true?
Static electricity will be harmful to the 1000w led lights, LED is not unique "patent" is commonly used in silicon materials, diodes, transistors, but also will be threatened. Even buildings, trees and animals can be damaged by static electricity (lightning is an electrostatic charge and we do not think about it here).
So how does static electricity damage electronic components? I do not want to go too far, I only talk about semiconductor devices, but also limited to diodes, transistors, IC, LED aspects.
But look at the LED, the voltage is positive to the LED, when the external voltage is less than the threshold voltage of the diode (the size of the material with the corresponding band gap), there is no forward current, the voltage added to the PN junction. When the voltage is reversely applied to the LED, when the external voltage is less than the reverse breakdown voltage of the LED, the voltage is also applied to the PN junction. At this time, the LED's virtual solder joint is also worth mentioning. , All without voltage drop! Because there is no current. After the PN junction puncture, the external voltage will be shared by all the resistance on the circuit. Where the resistance is large, which part of the voltage is high. In terms of LED, PN junction naturally bear most of the voltage. The thermal power produced at the PN junction is the voltage drop across it multiplied by the current value. If the current value is not limited, the excess heat will PN junction burn out, PN junction loss role and through.
LED is actually a diode, its area relative to each of the components in the IC is very large. Therefore, the parasitic capacitance LED is relatively large. Therefore, the static electricity in normal circumstances can not damage the led flood light 300w.
In general, static electricity, especially the static electricity generated on the insulator, will have a high voltage, but the amount of discharged electricity is very small, and the discharge current lasts for a short time. Electrostatic induction on the conductor, the voltage may not be high, but the discharge current may be large, and often sustained current. This is very harmful to electronic components.