ESD: Protection from damaging discharges
We’ve all been there – you touch the car door and get a tiny shock. Electrostatic discharge, or ESD for short, is relatively common in everyday life, and isn’t usually a big deal – unless there are electronic components nearby. If this is the case, the consequences of ESD can be serious, even if you don’t notice them at first.
Here, we provide information about how and where electrostatic discharge happens and the associated risks. You will also find out which products you can use to protect sensitive components from ESD, both at work stations and during transport.
What does ESD stand for and what is it exactly?
As mentioned above, ESD stands for electrostatic discharge. But how does this happen?
To explain it in simple terms, we can use an example from everyday life:
- You walk across a carpet in shoes.
- This creates friction, which in turn causes first your shoes, and then your body, to gain negatively charged electrons.
- If you then touch an object made of a conducting material, the handle of a car door for example, the charge jumps from your body to the object.
The same applies when two objects rub against each other, causing charges to be transferred – for example, when plastic boxes are pushed across a surface or when a conveyor belt is in operation.
Is ESD dangerous?
The short answer is not for people, at least not directly. Although you will experience a small electric shock at charges of 3,500 volts or more, it would take a lot more than that to damage your health.
However, receiving even a small shock like this could cause someone a moment of alarm, which could in turn lead to an accident and/or injury. And in certain environments, there is a danger that the sparks generated could cause an explosion.
First and foremost, though, electrostatic discharge is dangerous for electronic components.
What damage can ESD cause?
ESD can cause serious damage to electronic components, even when the charge exchange is so small that humans don’t notice it. The damage likewise often goes unnoticed.
The consequences for manufacturing firms:
- Electronic components can malfunction, putting equipment out of action. This may only happen after a certain period of time.
- It is often difficult to identify the defective parts.
- The consequences may include customer complaints, damage to company image and financial losses resulting from repairs and expensive replacement parts.
The risks associated with ESD are a growing issue as more and more companies start using electronic components, for example in the automotive industry.
Luckily there are ways of preventing these problems.
Good to know: discharges of just 5 V can cause major damage to microchips.
How to protect components from ESD
The best method of protecting sensitive components from damage resulting from ESD is to prevent charge from building up, and to ensure that objects and people can conduct electrostatic charge into the ground.
To this end, companies can set up an EPA (electrostatic protected area), also known as an ESD protected area, in which all materials are conductive. This should be done in accordance with the ESD standard IEC (DIN EN) 61340-5-1.
ESD protection starts from the ground up. ESD mats and other floor coverings drain static electricity into the ground. This can also be useful in the office, since high voltages can build up when office chairs are rolled across the floor. Anti-fatigue ESD mats are especially helpful for standing workspaces.
Use shelves with an ESD coating for storing electronic components. It’s important that the shelves are located within an EPA or are earthed. You can also store electronic components in ESD containers such as special box pallets or open fronted storage bins.
ESD work station
ESD tables, chairs, stools and anti-fatigue stools prevent dangerous discharges at work stations.
When carrying out work on sensitive electronic components, use only conductive tools, for example ESD screwdrivers.
Secure transport of electronic components
ESD protection is also important when transporting equipment from one room to another. We recommend using electrically conductive platform trolleys with ESD castors. Sealed ESD plastic boxes can also be used to transport sensitive components safely.
In EPAs, ESD shoes are a must. In accordance with the EN 61340-5-1 standard, these shoes must have a resistance of between 7.5 x 105 and 3.5 x 107 Ohm. They should ideally be paired with ESD wrist or heel straps, which are connected with an earthing cable, ensuring that the wearer is permanently earthed.
Final tip: check that you have the right humidity level
Low humidity leads to higher static build-up, and vice versa. This is because when the air is sufficiently moist, a thin layer of moisture develops on surfaces, making them conductive.
However, high levels of humidity aren’t ideal for sensitive components or the health of your staff, so it’s best to maintain humidity at between 40 % and 60 %.