Many friends or clients who have just contacted LED display screens are curious. Why do they have to wear shoes covers, electrostatic rings, and protective clothing such as static clothes when they visit LED module SMT room? To understand this issue, it is necessary to mention the knowledge related to electrostatic protection in the production and transportation of LED displays; many LED displays appear dead or not lit, mostly due to static electricity.
The source of static electricity in the production process of LED display screens
1, objects, materials
2, floor, work tables and chairs
3, overalls, packaging containers;
4. Painted or waxed surfaces, organic and fiberglass materials.
5, cement floor, paint or waxed floor, plastic floor tiles or floor leather.
6, chemical fiber work clothes, non-conductive work shoes, clean cotton overalls.
7, plastic, packaging boxes, boxes, bags, plates, foam plastic liners.
The harm of static electricity in the production process of LED display screens If any static electricity is ignored in production, it will cause the electronic equipment to malfunction or even damage it. When a semiconductor device is placed alone or incorporated into a circuit, static electricity may cause permanent damage to these devices even if power is not applied. As we all know, LED is a semiconductor product. If the voltage between two pins or more pins of the LED exceeds the dielectric strength of the device, it will damage the device. The thinner the oxide layer, the greater the susceptibility of the LED and driver IC to static electricity. For example, the solder is not full, there is a problem with the quality of the solder itself, etc., and a serious leakage path is generated, resulting in devastating damage.
Another type of failure is caused when the temperature of the node exceeds the melting point of semiconductor silicon (1415°C). Electrostatic pulse energy can generate local heat, so there is a direct breakdown of the lamp and IC failure. Even if the voltage is lower than the breakdown voltage of the medium, this kind of failure will occur. A typical example is that the LED is a diode composed of a PN junction, and the breakdown between the emitter and the base results in a drastic decrease in the current gain. After the LED itself or each IC in the driving circuit is affected by static electricity, it may not immediately appear functional damage. These potentially damaged components are usually displayed during use, so the impact on the lifetime of the LED products are It is fatal.
LED display production process is a very rigorous, subtle process, each link can not be omitted. The electrostatic protection of the display screen is also an important link in the production of LED displays. At present, people in the industry are not sufficiently aware of the electrostatic protection, and they are unable to meet the needs of professional LED display production. More professionals are required to continuously research and work together. discuss.
How to prevent static electricity in LED display production:
1) Training on the use of electrostatic sensitive circuit personnel for electrostatic knowledge and related technologies.
2) Establish an anti-static work area in which static-discharged floors, anti-static worktables, anti-static grounding leads and anti-static appliances are to be used, and the relative humidity should be controlled at 40 or more.
3) The harm caused by static electricity to the electronic equipment may be released anywhere from the manufacturer to the field equipment. The hazard is caused by insufficient, effective training and equipment manipulation failure. LEDs are devices that are sensitive to static electricity. INGAN wafers are generally considered "first place" susceptible to interference. And ALINGAPLEDSSHI "second place" or better.
4) Devices with damaged ESD can show dimming, blurring, extinguishing, short or low VF or VR. Devices that are damaged by ESD should not be confused with electronic overloads, such as: faulty current design or driving, chip mounting, wire shield grounding or encapsulation, or common ambient induced pressure.
5) ESD security and control procedures: Most ESD and EMD companies have very similar ESDs and have successfully implemented all ESD controls, controls, and main programs for the device. These programs are instruments that have been used to detect quality effects since ESD. The ISO-9000 certification also included him in the normal control process.