Electrostatic discharge, great harm
In the dry season, when you open the door, you will occasionally feel an electric shock. This is Electrostatic Discharge (ESD). When you feel an electric shock, the electrostatic voltage on your body has exceeded 2000 volts! When you see the discharge spark, the static electricity on your body is already as high as 5000 volts! When you hear the sound of the discharge, the static electricity on your body has reached 8000 volts! However, many modern high-speed very large-scale integrated circuits will be damaged when they encounter static electricity of only tens of volts or less. That is to say, when you touch these circuits, you neither feel nor see nor hear the electrostatic discharge, this circuit has been partially damaged or completely damaged, and you may still be looking for the cause of its hardware or software. . You may not realize it is the "ghost" of static electricity. Before the middle of the last century, static electricity was like a performance in a science museum, just an interesting physical phenomenon; however, static electricity has become a terrorist of high-tech modern industries.
There have been many fatal accidents caused by static electricity at home and abroad in recent years. In the military industry sector, electrostatic discharge causes accidental explosions of rockets (projectiles); in the petrochemical industry, electrostatic discharge has repeatedly caused gasoline to catch fire and explode; in the electronics industry, electronic components are damaged. Only in the United States is the annual loss caused by static electricity to the electronics industry. It amounts to tens of billions of dollars. Another form of electrostatic hazard is the hazard of electrostatic force. The dust collection effect of electrostatic force will affect product quality. In the production of large-scale integrated circuits, static electricity greatly reduces the chip yield. In the printing process, it is difficult to align the paper due to electrostatic attraction, which reduces production efficiency. In addition, electrostatic discharge also produces strong electromagnetic interference, and its frequency is very wide, from low frequency to more than several gigahertz. This kind of strong electromagnetic field has a short action time, but its intensity is far stronger than the electromagnetic field radiated by a mobile phone, which will interfere with the normal operation of some devices.
Static electricity is so harmful, how is it produced? Any substance is composed of atoms, and the basic structure of atoms is protons, neutrons and electrons. Scientists define protons as positively charged, neutrons are uncharged, and electrons are negatively charged. Under normal conditions, the number of protons and electrons of an atom are the same, and the positive and negative charges are balanced, so it appears uncharged to the outside. However, due to external effects such as friction or in the form of various energies such as kinetic energy, potential energy, thermal energy, chemical energy, etc., the positive and negative charges of the atoms will be imbalanced. The friction in daily life is essentially a process of constant contact and separation. In some cases, static electricity can be generated without friction, such as induced electrostatic electrification, pyroelectric and piezoelectric electrification, Helmholtz layer, jet electrification, etc.
Any two objects of different materials can generate static electricity as long as they are separated after being contacted. Of course, flowing air can generate static electricity. Why does flowing air generate static electricity? Because air is also composed of atoms, it can be said that static electricity may be generated at any time and any place in our lives. It is almost impossible to completely eliminate static electricity, but some measures can be taken to control static electricity so that it does not cause harm. For different environments and different protection objects, there are different protection methods and measures. There are many ways to reduce static electricity to reduce the hazards of static electricity. For example, some static protection equipment and measures are used to control the static electricity of the human body and the environment. The staff can wear anti-static clothes and shoes and lay anti-static ground. In addition to good static control hardware measures, there must also be static control software measures. This is the static control management and certification system and anti-static knowledge training. Many departments abroad have specialized static control management personnel.
On the other hand, some measures can be taken when designing the circuit to improve the antistatic ability of the product.
Static electricity has many hazards, can static electricity also be used? The answer is yes, the use of static electricity can benefit mankind. What everyone knows most is electrostatic photocopying, which is now widely used. Electrostatic dust removal has the advantage of high efficiency. Nowadays, many air purifiers use static electricity to absorb small dust in the air to purify the air. In agriculture, the use of electrostatic spray can greatly improve efficiency and reduce the use of pesticides, which is economical and environmentally friendly. There are many applications of static electricity. For example, the seeds treated by static electricity have strong disease resistance, reduced disease occurrence, high germination rate, and increased yield; the ozone produced by electrostatic discharge is an intensifier, which has a strong antibacterial effect; Water is not only good for sex but not easy to cause scale. The electret membrane with static electricity can also prevent various soft tissue injuries. It has the functions of eliminating blood stasis and reducing swelling. Static electricity can also be used for spraying, and the shells of household appliances such as washing machines and refrigerators are sprayed very uniformly with static electricity.
In short, static electricity is a mysterious thing, although we cannot see it with the naked eye or touch it with our hands, static electricity is constantly generated and disappeared around us. It not only causes harm to humans, but also can be used by humans.