What is an ESD Protected Area or EPA ?
An EPA (ESDPA – Electrostatic Discharge Protected Area) is an area that ensures the protection from electrostatic discharges. Electrostatic discharge (ESD) is an electrical short or dielectric breakdown; a sudden flow of electricity caused by contact between two electrically charged objects.
In an EPA the discharges and damage of static sensitive devices from the static electricity are minimized by various methods.
An EPA is a controlled environment against static electricity. All the equipment’s, tools, peoples, etc., that is the entire work area should have the same electrical potential. It is achieved mainly by providing electrical contact with each other and grounding them. Also, by following various measures to avoid ESD.
why ESD protection is required?
An electrostatic discharge can damage electronic devices or components which are sensitive to electrostatic discharge.
Electrostatic-sensitive devices like PC circuits, smartphones circuits, etc., are highly vulnerable to static discharge. The effect of ESD may be immediate or delayed. An electrostatic discharge can cause partial damage, reduced performance, malfunction, reduction in lifespan of the device, etc…
ESD protected workstation requirements
Some of the basic requirements in an EPA workspace,
ESD Flooring – An ESD control flooring have a coating to be electrically conductive. The flooring permits the discharge of static energy through desired ground points.
Work surface – ESD workbench should have ESD protective mat which ensures the work surface dissipates static energy.
ESD safe clothing – ESD safe anti-static aprons or LAB coats need to wear inside the EPA. Because normal clothing has the possibility to generate and carry static energy.
Anti-static foot wears – Static dissipative footwear is required to discharge the build-up of static electricity while maintaining enough electrical resistance.
Wrist Straps – The static electricity stored in the body of a person can be discharged into the devices. A wrist wrap actually providing ground to the person. It acts as a channel for static electricity to ground, it removes static energy from the person body to ground.
Ionization – Air ionization helps to remove static charges from isolated conductors and insulating materials. Air ionization neutralize the static charge on the surface by attracting positively and negatively charged ions.
Antistatic bag – Antistatic bags need to be used for storing electronic components; it has a static dissipative coating.
Static dissipative paint – It is necessary to use static dissipative paint on the surfaces of EPA.
The measures for EPA requires a period of testing and maintenance for the proper functioning of Electrostatic discharge protection.
Also, the ESD protected areas should be marked and indicated properly with EPA stickers, warning, floor marking tape, etc., which helps to avoid accidental mistakes.