Static Electricity Protection Methods
(1) Use of Antistatic Materials: Metals are conductors, and their high leakage current can damage devices. Furthermore, insulating materials are prone to triboelectric charging, so neither metals nor insulating materials can be used as antistatic materials. Instead, materials with a surface resistivity below 1*10⁵ Ω/cm (so-called electrostatic conductors) and a surface resistivity of 1*10⁵-1*10⁸ Ω/cm (e.g., electrostatic sub-conductors) are used. For example, commonly used antistatic materials are made by mixing conductive carbon black into rubber, controlling the surface resistivity below 1*10⁸ Ω/cm.
(2) Leakage and Grounding: Grounding is used to provide a path for static discharge at points where static electricity may be generated or has already been generated. An "independent" grounding wire is established by burying a grounding wire. Ensure the resistance between the ground wire and the earth is <10Ω (see GBJ179 or SJ/T10694-1996).
Grounding method for electrostatic protection materials: Connect the electrostatic protection material (such as work surface mats, floor mats, anti-static wrist straps, etc.) to a conductor leading to an independent earth wire through a 1MΩ resistor (see SJ/T10630-1995). Connecting a 1MΩ resistor in series is to ensure a current discharge of <5mA to ground, called soft grounding. Equipment casings and electrostatic shields are usually directly grounded, called hard grounding.
(3) Elimination of static electricity on conductors: Static electricity on conductors can be discharged to the earth using grounding. The voltage and discharge time of the discharge body can be expressed by the following formula: UT=U0L1/RC Where UT-voltage at time T (V), U0-initial voltage (V), R-equivalent resistance (Ω), C-equivalent capacitance of the conductor (pF). Generally, it is required that the static electricity be discharged within 1 second. That is, a safe zone where the voltage is reduced to below 100V within 1 second.
Mobile static electricity eliminator