Electrostatic Protection in Practice: Equipping EPA Premises

Protecting electronic components and equipment from electrostatic discharge (ESD) is a necessity nowadays. Electrostatic discharge can damage or even destroy sensitive electronic components, costing billions of dollars worldwide. To avoid this, it is important to equip working environments with what are known as EPA zones (Electrostatic Protected Area). The basic elements of such protection are ESD wristbands, ESD flooring and other specific elements. In this article, we will cover the basic prerequisites for EPA equipment zones and standards that relate to the protection of electronic components from electrostatic discharge.

What is EPA Space

There are many aspects to think about in an ESD suppression project. One of the main elements of ESD protection is the EPA (Electrostatic Discharge Protected Area). This is an area where sensitive components can be handled with acceptable risk.  It can only contain objects that prevent the formation of ESD. Under no circumstances can there be any insulators (paper, unprotected plastic, rubber, etc.). The space can be an entire building, a room or a single workstation.

Marking and Entering the EPA Area

The EPA area must be visibly marked so that it is clearly distinguishable from the rest of the operation. In simple cases, black and yellow demarcation tape on the floor is used to define the boundary of an EPA area. The disadvantage of this solution is that such a space is not protected against unauthorized access.

Therefore, physical barriers are more often used to prevent unauthorised and untrained persons from entering the area. The entrance to the EPA area has a gate that allows entry only to persons who have resistance within the values set by the regulations. In practice, this means that the person is wearing ESD clothing, ESD footwear and an ESD wristband. They are then tested to ensure that they meet prescribed parameters before they are allowed to enter the EPA area.

EPA Facilities Area

Only objects that help to dissipate electrical charge while preventing its generation can be in the EPA area. Such items include:

• ESD furniture (chairs, tables, work surfaces, lamps)
• ESD flooring
• ESD tools
• ESD packaging material and so on

Each of these elements contributes to reducing the risk of ESD. The more elements a company uses in its ESD suppression program, the more it minimizes the risk of ESD. In automotive and other manufacturing companies that work with sensitive electronics, maximum use of these elements is made because the protection of electrical components is extremely important there.

In addition, EPA facilities are regularly inspected and audited to ensure that they are only equipped with items that reduce the risk of ESD. It is strictly forbidden to have an object or material in these areas that could cause a discharge.

Choosing Protective Elements

As noted above, each of the elements contributes to reducing the risk of ESD. However, if you are going to opt for the notional minimum protection that will contribute to maximum ESD protection, then we recommend at least ESD footwear, an ESD wristband and ESD flooring. ESD flooring has the advantage that, in addition to effectively dissipating the generated charge, it prevents excessive charge from building up. Just to give you an idea – a person walking on carpet in winter can build up a charge of up to 35,000 volts! On the other hand, a high-quality ESD flooring will prevent the generation of a charge of more than 100 volts.

Regular Checks

However, choosing the right product is not the end of the ESD suppression programme. On the contrary. Each product should be checked regularly to ensure that it has not lost its ESD properties over time. Therefore, the ESD suppression program must define how the subject will be inspected and how often.

The European Technical Standard EN 61340 – Protection of electronic components against electrostatic effects is useful in this respect. For each object, it specifies what parameters it must meet if plugged into the system. If you have a properly wired floor, then even with the passage of time it must meet R_g < 1 × 10 Ω (resistance to ground). Testing is conducted by a trained ESD programme coordinator.

What to Check

Put simply, everything. All items that are in the EPA area should be checked regularly. If they do not pass testing or do not meet standards, they must be removed from the premises.

Comprehensive Programme

Each company setting up an EPA site must develop a system designating a person responsible for compliance with the established regulations, usually the ESD coordinator. This person must:

1. Define equipment requirements for the space
2. Identify responsible personnel to enter the area
3. Ensure training and regular retraining of authorised persons
4. Develop guidelines for working in the EPA area
5. Propose a schedule for testing items in the EPA area. Any such testing should be followed by a report demonstrating compliance with the established parameters.

If you would like to learn more about EPA programmes in ESD and emission reduction, please contact us at info@fortelock.com.