What is ESD? A plain guide for buyers

How static builds up

Static charge is made when two materials touch and separate, for example a shoe on a floor, a hand on a plastic tray or a garment brushing a chair. Insulating materials hold that charge. Dry air makes it worse.

Why small voltages matter

• People usually feel a spark at around 3,000 V or more.
• Many electronic parts can be damaged at 100 V or below. You will not feel or see the discharge that does it.
• Damage can be immediate (the part fails) or hidden (the part works, then fails early in service).

The four basic controls

1. Ground people and conductive items so charge cannot build up: wrist straps, footwear and flooring.
2. Shield and protect parts in storage and transit: shielding bags, trays and boxes.
3. Neutralise charge on insulators that cannot be grounded, using ionisers.
4. Keep unnecessary insulators away from sensitive parts.

What an ESD protected area is

An ESD protected area (EPA) is a marked space where these controls are in place and checked. Parts that are sensitive to static are handled only inside it, or in protective packaging.

Where to go next

• See the guide on ESD protected areas for what goes in one.
• See the standards guides for the limits your programme must meet.

Keep reading

• ESD protected area basics
• ESD vs anti-static
• ESD standards at a glance