Understanding ESD in Electronics
- Sophie Bill
- 3 hours ago
- 3 min read
What is ESD?
ESD stands for Electrostatic Discharge. It is the sudden flow of electricity between two objects with different electrical charges when they come into contact or close proximity.
E.g. The shock you feel when you are walking across a carpet then touch a doorhandle.
Why is ESD important in electronics?
ESD can be a silent killer of electronic components because the discharge is often too small for humans to notice, yet still large enough to damage sensitive devices. Humans feel shocks above 3000 volts whereas electronic components can be damaged with less than 10 volts.
The rapid discharge of static electricity can damage semiconductor junctions and, in severe cases, generate enough heat to cause permanent component failure. Bare PCBs (PCBs with no components) are made to withstand very high voltages so ESD is rarely an issue.
ESD damage is not always immediate. A component may appear to function normally after an ESD event but suffer hidden damage that reduces its lifespan or causes intermittent failures later in the field.
Types of ESD Damage
Catastrophic failure – component stops working immediately.
Latent failure – component appears to work but has hidden damage that may cause future reliability issues.
What can cause ESD?
ESD can be caused by many different things.
Handling. Static electricity from your body transfers directly into the device.
Friction. Packaging, clothing and sliding against surfaces can all generate a static charge.
Dust. Moving dust particles generates static charges.
Tools. Everyday tools you might find on your workbench can be responsible for generating static charges. E.g. tape dispensers, plastic rulers, soldering irons, fans, printers.
But how do I prevent it?
There are lots of ways to prevent ESD, not all will be relevant for your workplace, you will need to analyse your work areas and choose the appropriate prevention methods.
Handling: When handling ESD-sensitive devices devices you need to ensure you are grounded. There are various ways you can do this, the most common is by using wrist straps. When transporting it is important to use anti-static racks.
Friction:
Packaging: Anti-static packaging is widely available and can come in most forms e.g. vacuum seal bags, bubble wraps, boxes. You want to avoid the use of high static materials such as paper, foam and cardboard.
Note: As long as the primary packaging is anti-static e.g. The boards are secure in anti-static bags, then they are safe to be packed in non-anti-static packaging. Customer requirements should always be checked first.
Clothing: Anti-static clothing should be mandatory for all staff working on ESD-sensitive devices. Anti-static shoes are also great.
Surfaces: Anti-static matting across work benches is an easy way to prevent static charge build up when working on product.
Dust: Daily cleaning with the use of air ionisers and air purifiers can all be used to help create dust free environments.
Tools: All tools on work benches need to be made of anti-static materials and conform to IEC/BS EN 61340-5-1.
Training: Regular training for staff ensures knowledge is kept up to date and helps to reduce risks.
How we control ESD at Advanced Assembly Solutions
At Advanced Assembly Solutions, we have over 35 years of experience manufacturing electronic assemblies and understand the risks ESD presents to sensitive components.
Upon joining our company employees are given ESD training with refreshers completed annually. All employees and visitors must wear the provided anti-static coats and if applicable anti-static shoes. Before starting any work, we use the ESD wrist strap tester before starting at a ESD-safe workstation.
For our customers, we invest in anti-static bubble wrap, packing film and 3 different types of anti-static bags. If needed, we can also ship in anti-static boxes although we highly encourage our customers to allow us to recycle and reuse our packaging.
