How to achieve the best anti-static effect
First, the basic principles of electrostatic protection
1. Suppress the accumulation of static charge;
2. Eliminate the static charge that has been generated.
Second, the basic measures to eliminate static electricity
Measures to eliminate static electricity can generally be attributed to “ground”; second, “device” (static eliminator); third, “agent” (plus antistatic agent); fourth, “shield”.
Ground
Grounding is the connection of some anti-static products or other equipment to a ground wire. A buried line method is used to establish an "independent" ground line. The resistance between the ground wire and the earth is <10Ω, which acts to discharge the charge that may accumulate on the conductor. The static electricity accumulated on the conductor (such as the human body) is usually grounded by grounding.
Grounding is implemented by the following methods:
1 The human body is grounded through the wrist strap.
2 The human body is grounded through anti-static shoes (or shoelaces) and an anti-static floor.
3 The work surface is grounded.
4 Test instrument, tool holder, soldering iron grounding.
5 Anti-static floor, grounding pad.
6 Anti-static transfer vehicles, boxes and racks should be grounded as much as possible.
7 Anti-static chair is grounded.
2. Using a static eliminator
Such as ion fan, ion wind gun is a good static eliminator, his principle is to generate a large number of positive and negative ions on the static eliminator, and then blow these ions to the static place by the wind, the static electricity will attract the opposite polarity The ions are neutralized, and the static electricity accumulated on the surface of the product or device is thus neutralized and eliminated.
3. Use static eliminator
The static elimination agent can be used to wash the surface of the instrument and the object, and the static electricity on the surface of the object can be quickly eliminated. The antistatic agent uses fats and oils as raw materials, and its main component is quaternary ammonium salt. Its function is to make the surface of chemical fiber, rubber, plastic and other objects adsorb moisture in the air and increase the electrical conductivity.
4. Electrostatic shielding
The most common method is to use electrostatic shielding bags and anti-static turnover boxes as protection. The electrostatic sensitive components will be exposed to static electricity during storage or transportation. The electrostatic shielding method can weaken the influence of external static electricity on electronic components.
5. Control the humidity of the environment
When the relative humidity of the air is above 65-70%, the surface of the object tends to form a very thin film of water. The water film can dissolve the CO2 in the air, so that the surface resistivity is greatly reduced, and the static charge is less likely to accumulate. If the relative humidity of the surrounding air drops to 40 to 50%, the static electricity is not easily dissipated, and it is possible to form a high potential. A common method of increasing the humidity of the air is to spray water mist into the air. Rotary fan sprayers are generally used, but the machine is not explosion-proof and must be blown from outside the wall.