ESD stands for electrostatic discharge. A large potential difference causes a spark or disruptive discharge, which produces high electric voltage pulses in electronic devices. Humans first feel an electrostatic charge from 3000 volts, and in most cases the discharge is harmless, with the moment of shock being the worst part.
When is ESD dangerous?
Sparking can already occur at 10000 volts and can cause explosions if flammable liquids or gases are being handled. Static electricity is produced, for example, when running on a carpeted floor, whereby a person can become charged to approx. 30000 volts in some cases. The effects of ESD are insidious, meaning that the damage is not immediately visible, and the causer often does not notice it. The consequences can become costly, especially if the assembly is installed in devices for sensitive applications. Sensitive components can be destroyed from just 40 volts.
A work area equipped with ESD protective measures where electrostatically sensitive components can be handled without damaging them.
A comprehensive EPA (Electrostatic Protected Area) protection area includes the following areas:
- Personal grounding
- Measurement technology
The ESD-protected workstation should be ergonomically adaptable. Electrostatic charge is dissipated via the worktop and a earthing cable so that the workstation remains charge-neutral.
Measurement technology Protective device must be metrologically tested regularly. When entering an EPA, measurements and regular personal inspections must be performed. Work benches, floor mats and earthing connections should
be checked monthly and ESD monitoring instruments should be checked annually.
People are the main source of electrostatic charges. Shoes and a wrist strap with an earthing cable should be mandatory for employees in electronics production. Wrist strap and shoe testers facilitate the daily inspection of EPA effectiveness. The chair or standing aid should also have ESD protection.
Conductive ESD shelving and containers for transporting and storing components protect endangered components. Assembly trolleys should be fitted with conductive wheels.
Markings on the flooring indicate ESD protection areas. Signs and labels indicating potentially endangered components and assemblies are also important.