ESD Protected area or EPA

An ESD Protected area or rather known as EPA is an area where workers work and deal with ESD sensitive items in a safe environment from harmful electrostatic charges. From a quick glance, this EPA is decorated with many and different type of ESD protective materials and equipments which are used to control the generation and accumulation of electrostatic charges, such as ESD mat, ESD wrist strap, ESD tote box, ESD air ionizer, ESD chair, ESD flooring etc. The EPA is normally identified with a clear signage to indicate that the area is an ESD Protected area.


Controls at EPA
When working in an EPA, workers are required to wear wrist strap while handling the ESD sensitive parts in a seated position.

Tailoring could be made when workers are dealing with hazardous voltage. The use of wrist strap can be exempted with some technical justifications.

The work surface shall be grounded and both conductive and dissipative work surfaces are allowed to be in the EPA, depending on the product’s requirement.

Non essential process insulator such as coffee cup, plastic bottle and personal plastic bag are not allowed to be in an ESD Protected workstation. When essential process insulators are needed on the workstation, the 2kV/inch rule is applied.
When scanning the workstation with a static field meter, a source that gives any reading above the 2Kv in an inch distance shall be kept in a distance at least 30 cm away from the ESD sensitive parts.
Alternatively, ESD air ionizers can be used to neutralize the electrostatic charges on the insulative source or other mitigating ways such as shielding technique can be applied.

Workers shall be trained periodically while working in an EPA. Any untrained visitors such as vendors, customers and external auditors shall be accompanied by a trained worker while in the EPA.

Jigs, tools or surface of automated equipment that has direct contact with the ESD sensitive parts shall be dissipative or conductive in nature and grounded.

ESD garments that are worn by workers shall be checked periodically to ensure
continuous functionality during use in the EPA.

Most established organizations have installed ESD flooring in the EPA. While the presence of ESD flooring definitely make ESD controls much easier, it must be noted that ESD flooring does not work alone and in fact it only works effectively with the presence of ESD footwear.

It is the role of the ESD Coordinator to ensure ESD controls at the ESD Protected area is complying with ANSI/ESD S20.20 standard requirements.

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