What are the hazards of static electricity to electronic components and how to protect them?
Depending on the type of electronic components, the degree of damage caused by static electricity is also different. The lowest static voltage of 100V will also cause damage to them. In recent years, with the development of electronic components becoming more integrated, the corresponding electrostatic voltage is also required to be continuously reduced.
The electrostatic voltage induced by the human body is generally above 2-4KV, which is usually caused by slight movements of the human body or friction with insulators. In other words, if the electrostatic potential we carry in our daily lives comes into contact with ICs, almost all ICs will be destroyed. This danger exists in any working environment where electrostatic protection measures are not taken. The damage caused by static electricity to IC is not only reflected in the manufacturing process of electronic components, but also during the assembly and transportation of IC.
To solve the above problems, the following various electrostatic protection measures can be taken:
1. Electrostatic protection at the operating site. Static-sensitive devices should be operated in an anti-static working area;
2. Human body electrostatic protection. Operators wear anti-static overalls, gloves, work shoes, work caps, and wrist straps;
3. Antistatic protection during storage and transportation. Static-sensitive devices cannot be stored and transported in a charged state.
To achieve the above functions, the basic approach is to try to reduce the voltage of the charged object to within the safe value required by the design. That is to say, the charge (Q) and resistance (R) in the following formula are required to be small, and the electrostatic capacity (C) is required to be large.
V=I.R Q=C.V (where V: voltage, Q: charge I: current C: electrostatic capacity R: resistance)
Of course, the resistance value is not as low as possible. Especially in anti-static areas of large-area places, safety measures such as leakage must be taken into consideration before selecting materials.
Electrostatic protection measures
Inspect and install IC electrostatic protection workplaces. The purpose of anti-static measures in this process is to keep the workplace, including the human body, at the same potential. The specific methods are as follows:
1. Connect the 1 megohm resistor and then ground it, and wear an anti-static wrist strap for operation;
2. Ground testers, tools, soldering irons, etc.;
3. Lay an anti-static mat on the work surface and then ground it;
4. Operators should wear anti-static work clothes and work shoes;
5. Lay anti-static flooring or conductive rubber mats on the ground;
6. The same potential should be maintained during IC transportation and packaging.
Testing cycle and precautions for anti-static performance
Anti-static mats, floors, work shoes, work clothes, turnover containers, etc. should be tested at least once a month. Anti-static wrist straps, air guns, fans, instruments, etc. should be tested once a day. When testing, factors such as temperature and humidity of the place being inspected must be taken into consideration.