Inventory the wrong anti-static methods for you
In many electronic factories, they use a lot of anti-static products, why do static damage often occur? Let’s talk about the common wrong anti-static methods in factories.
1. No anti-static product testing equipment
The most common mistake is that many companies have purchased many anti-static products, but they have not purchased some commonly used anti-static product testing instruments. We know that each product has a certain period of use, and the quality is good or bad. Without some commonly used testing instruments, we don't know whether the product is damaged or the quality is good. In this way, there is no anti-static effect.
2. Poor ground connection
a. The anti-static system must have an independent and reliable grounding device, the grounding resistance should generally be less than 10Ω, and the burying and testing methods should meet the requirements of GBJ97.
b. The anti-static ground wire must not be connected to the power neutral wire or shared with the lightning protection ground wire. Because lightning strikes and other phenomena will affect product performance and personal safety through the loop.
c. Use a three-phase five-wire system for power supply, and its earth wire can be used as an anti-static ground wire (but the neutral wire and the ground wire must not be mixed).
d. The cross-sectional area of the grounding trunk line should be no less than 100mm2; the cross-sectional area of the branch trunk line should be no less than 6mm2; the grounding wire of the equipment and workbench should be a multi-strand plastic-coated wire with a cross-sectional area of not less than 1.25mm2, and the color of the grounding wire should be yellow-green Appropriate.
e. The connection method of the grounding trunk line should be brazed.
f. The connecting terminals of anti-static equipment should ensure reliable contact, easy to assemble and disassemble, and allow the use of various clip-type connectors, such as fish clips, plug sockets, etc.
g. A grounding system monitoring and alarm device should be installed in workplaces that require high grounding resistance.
3. Use anti-static products as ordinary products
Many companies treat anti-static products as ordinary products, thinking that the products can be used without deforming or breaking. In fact, this is a misunderstanding. For example, the anti-static wrist strap can only be used for a few months. After a period of use, the appearance may not be damaged. However, it is often found that the wrist strap is broken during testing.
4. Not paying attention to socks and insoles
Usually people wear socks or insoles when wearing anti-static shoes. People who are prone to sweating will also conduct static electricity because of these socks and insoles. However, if people who are not prone to sweaty feet wear some non-anti-static shoes With insoles, the socks and insoles cannot conduct static electricity, so the static electricity of the human body cannot be introduced into the earth through the shoes. Therefore, place a "human body comprehensive resistance tester" at the entrance of the computer room or factory building. The human body comprehensive tester can quickly and accurately detect those who wear unqualified anti-static shoes, socks and insoles. Workers are advised to wear anti-static slippers in the summer and not to wear zizi. In winter, they can wear cotton socks but not nylon socks.
5. Wear only anti-static shoes and not anti-static clothes
In addition to wearing anti-static shoes, people must wear anti-static overalls to better control the body's static electricity. Because clothing can also carry very high static electricity, especially now that most clothing is made of chemical fiber, it can generate thousands of tens of thousands of volts of static electricity.
6. Wear only anti-static clothes and not anti-static shoes
Experiments have shown that people only wear anti-static work clothes, such as not wearing anti-static shoes and not having a good anti-static floor, the anti-static effect is extremely poor.
7. Anti-static clothes and shoes are worn but there is no anti-static floor and no anti-static wrist strap
We know that the static electricity of the human body is usually led into the anti-static floor through anti-static shoes, or into the ground through the wrist strap. If there is no anti-static floor and anti-static wrist strap, it will be difficult to conduct the static electricity of the person. It is best for companies with conditions to have anti-static floor and anti-static wrist straps, and companies without conditions should at least have anti-static wrist straps.
8. Incorrect use of the wrist strap
Wrist straps are relatively easy to damage, so they must be checked every day. Good wrist straps will not conduct electricity due to workers wearing too loosely. So the best way is to monitor them at any time with an online wrist strap monitor. However, many companies don't even have a wrist strap tester. A wrist strap is used for more than a year before it is broken. This will not be able to discharge static electricity.