Harm of static electricity to electronic components and its protection principle
? ? ? Electronic components are damaged by static electricity according to their types, and the lowest static voltage of 100V will also damage them. In recent years, with the development of electronic components tends to be integrated, the corresponding electrostatic voltage is also decreasing. ? ? ? The electrostatic voltage induced by the human body is generally above 2-4kv, which is usually caused by the slight action of the human body or the friction with the insulator. In other words, if the electrostatic potential in our daily life comes into contact with IC, almost all IC will be damaged. This danger exists in any working environment without electrostatic protection measures. The damage of static electricity to IC is not only reflected in the manufacturing process of electronic components, but also in the process of IC assembly and transportation. To solve the above problems, the following electrostatic protection measures can be taken: 1. Electrostatic protection at operation site. Electrostatic sensitive devices shall be operated in the anti-static working area; 2. Electrostatic protection of human body. Operators shall wear anti-static work clothes, gloves, work shoes, work hats and wrist straps; 3. Electrostatic protection during storage and transportation. The storage and transportation of electrostatic sensitive devices shall not be carried out in a charged state. ? ? ? To realize the above functions, the basic method is to try to reduce the voltage of charged objects and reach the safety value required by the design. That is, the charge (q) and resistance (R) in the following formula shall be small and the electrostatic capacity (c) shall be large. ? ? ? V=I.R Q=C.V ? ? ?Where V: voltage, Q: charge, I: current, C: electrostatic capacity, R: resistance ? ? ? Of course, the lower the resistance value, the better. Especially in the anti-static area of a large area, the selection of materials must be carried out after considering safety measures such as leakage.
Electrostatic protection measures
? ? ? ?Check and install IC electrostatic protection workplace. The purpose of anti-static measures in this process is to keep the workplace including human body at the same potential. The specific methods are as follows: 1. Connect the 1 megohm resistance and then grounding, and wear anti-static wrist strap for operation; 2. Grounding the tester, tools, soldering iron, etc; 3. Grounding after anti-static table mat is laid on the worktable; 4. Operators wear anti-static work clothes and shoes; 5. Anti static floor or conductive rubber floor mat shall be paved on the ground; 6. IC shall maintain the same potential during transportation and packaging.
? ? ? Anti static rubber plate (table mat, floor), work shoes, work clothes, turnover containers, etc. shall be tested at least once a month. Anti static wrist strap, air gun, fan and instrument shall be tested once a day. During the inspection, the temperature, humidity and other factors of the inspected site must be considered.
Testing cycle and precautions of anti-static performance
Anti static experts have focused on the R & D and production of anti-static products for 26 years