by on May 31, 2024
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Static electricity is a very harmful devil in the electronic product production industry. There are countless electronic components damaged by static electricity all over the world, causing economic losses of tens of millions of dollars every year. Therefore, preventing static electricity from damaging electronic components is a very important task in the electronics industry. In recent years, the production technology of LED display screens has gradually matured in my country, and the wide application fields and popularization have become a trend. However, in the production of LED display screens, especially LED packaging and application companies. In the process of preventing static electricity, any problem in any link will cause damage to the LED, making the performance of the LED deteriorate or even fail. We know that the static electricity of the human body (ESD) can reach about 3,000 volts, which is enough to break down and damage the LED chip.
First of all, let's summarize the causes of static electricity:
From a microscopic point of view, according to the theory of atomic physics, matter is composed of molecules, molecules are composed of atoms, and atoms are composed of negatively charged electrons and positively charged protons. When two different objects come into contact with each other, one object loses some charge, such as electrons are transferred to another object to make it positively charged, while the other object gets some remaining electrons and becomes negatively charged. If the charge is difficult to neutralize during the separation process, the charge will accumulate and the object will be charged with static electricity.
From a macroscopic point of view, the reasons are: friction between objects generates heat, which stimulates electron transfer; contact and separation between objects generates electron transfer; electromagnetic induction causes unbalanced distribution of surface charges on objects; the combined effect of friction and electromagnetic induction. Electrostatic voltage is generated by the mutual contact and separation of different kinds of substances. This effect is known as triboelectrification, and the resulting voltage depends on the properties of the materials themselves that are rubbing against each other. Due to the actual production process of the LED display, it is mainly the direct contact and indirect contact between the human body and related components that generate static electricity.
Then understand the harm of static electricity in the production process of led display:
If anti-static is ignored in any link of production, it will cause electronic equipment to malfunction or even damage it. When semiconductor devices are placed alone or loaded into a circuit, even if no power is applied, static electricity may cause permanent damage to these devices. As we all know, LED is a semiconductor product. If the voltage between two or more pins of the LED exceeds the breakdown strength of the component medium, the component will be damaged. The thinner the oxide layer, the greater the sensitivity of the LED and driver IC to static electricity. For example, the solder is not full, the quality of the solder itself has problems, etc., which will cause serious leakage paths and cause devastating damage.
Another type of failure is caused when the temperature of the node exceeds the melting point of semiconductor silicon (1415°C). The pulse energy of static electricity can generate local heating, so there is a failure of direct breakdown of the lamp tube and IC. This failure occurs even if the voltage is lower than the breakdown voltage of the medium. A typical example is that the LED is a diode composed of a PN junction, and the breakdown between the emitter and the base will reduce the current gain sharply. After the LED itself or the various ICs in the driving circuit are affected by static electricity, functional damage may not occur immediately. These potentially damaged components usually show up during use, so the impact on the life of the display screen is great. is fatal.
Finally, summarize how to prevent static electricity in the production of led indoor video wall display screens:
1) Conduct electrostatic knowledge and related technology training for personnel using electrostatic sensitive circuits.
2) Establish an anti-static work area, use static-discharge floors, anti-static workbenches, anti-static grounding leads and anti-static appliances in this area, and control the relative humidity above 40.
3) The harm caused by static electricity to electronic equipment may be released anywhere from the manufacturer to the field equipment. Hazards are caused by inadequate and effective training and failure to operate equipment. LEDs are static sensitive devices. INGAN chips are generally considered "first" to be disturbed. And ALINGAPLEDSSHI "Second" or better.
4) ESD damaged equipment can display dim, fuzzy, extinguished, short or low VF or VR. ESD damaged equipment should not be confused with electronic overload, such as: due to wrong current design or driving, die attach, wire shield grounding or packaging, or general environmental induced stress, etc.
5) ESD safety and control procedures: Most electronic and electro-optical companies have very similar ESD and have successfully implemented ESD control, manipulation and main procedures for all devices. These procedures have been used since ESD since ancient times to detect mass effect instruments. ISO-9000 certification also includes him in normal control procedures.
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