If your employees regularly handle electronic products that are sensitive to damage from static electricity, then it’s likely your business should be using Electro-Static Discharge (ESD) matting. Many electronics standards insist on static control, such EN61340-5-1 (or ANSI S4.1 S20:20 in the US).
Being such a critical, yet also simple, part of your working environment, it’s easy for ESD matting to go overlooked. That’s why we’ve put together this helpful guide.
The basics of ESD matting
The essential thing to know about ESD matting is that it shields equipment from static electricity discharges. ESD mats mainly sit on worktops in work areas where charges can build up. ESD matting generally has two main components, a static dissipative top layer and a conductive bottom layer. An ESD mat offers a simple path to ground for the static electricity.
Without an ESD mat, electronic equipment can be at risk from static discharges. As little as 5v static discharge can damage some electronic components. With ESD mats – used alongside other measures like anti-static tools, clothing, footwear, flooring and packaging, as well as grounding straps – you are protecting your products and processed from unseen damage from static discharges.
Where would you typically use ESD matting?
We’ve mentioned floors and worktops above, but it pays to be more specific.
You’d often see ESD matting used in workspaces like:
- Computer server rooms
- Assembly lines
- ESD Protected Areas (EPA’s)
- Microchip manufacturing plants
- Electronics Manufacturing
- Clean rooms
- And more besides
It’s also worth mentioning that even areas that may occasionally encounter static might benefit from ESD mats.
For instance, electronic devices boxed up in protective packaging may still need to be stored in warehouses and storage areas. ESD matting is often placed on the storage shelves to add an additional layer of protection from static generated by the stacking process.
Types of ESD mats
We couldn’t call this post ‘everything you need to know about ESD matting’ without covering the types of ESD mats available.
Worktop ESD mats are typically thinner than floor mats. They usually come in either smoothly or lightly embossed finishes – the latter helping to reduce glare and aid workers with complicated electronic assembly tasks. With that in mind, bench mats tend to come in bright colours to help workers find smaller components on their surface, and are designed to be used with other ESD controls such as wrist straps and grounding points.
Underfoot ESD mats are usually larger and thicker than bench mats as they need to absorb more wear and tear. They feature heavier embossing, or sometimes grooves, to prevent workers from slipping. Additionally, many come with cushioning to make standing on them for hours at a time more comfortable. Colour-wise, they’re typically dark to hide dirt and scuffs from workers’ shoes – though this can make seeing components difficult if they accidentally drop from the worktop onto the floor. ESD floor mats are designed to work as part of a wider ESD protection scheme, incorporating items like ESD footwear.
ESD matting materials
We’ve outlined the basics of ESD matting above, but this is where we peel back the layers – literally, in some cases.
There are four types of ESD matting compositions. Each offers different levels of static resistance, and each is typically used for different reasons. One of the basics of ESD matting is that these are measured in three ways:
- Resistance To Ground (RTG): The main measurement, and the one we’ll focus on most in the examples below. RTG measures the resistance given between the most heavily used part of the ESD mat and the electrical ground.
- Resistance to Groundable Point (RTGP): This functions like RTG with one difference. It measures the resistance between a single point on the mat’s surface and the grounding point of the work surface.
- Resistance Point to Point (RTP):Surface resistance from one part of the mat’s surface to another point ten inches apart.
Homogenous vinyl and rubber ESD mats
Solid vinyl mats are typically made up of a dissipative one-layer polymer mix. They’re highly durable but costly, with electrical performance, usually at 107–109,Ohms/square.
Three-layer vinyl ESD mats
ESD matting with three layers sandwiches a conductive layer between the dissipative top layer and a dissipative bottom layer– the centre of which is highly conductive – 102–106 ohms/square.
The conductive layer removes the static charge to the ground quickly. However, the top layer has a higher surface resistance (dissipative) at 107–109, as many small SMT components in today’s world can be damaged if the static discharge is too fast. Any charge goes through the dissipative layer into the conductive layer to earth.
The top layer meanwhile adds cushioning for the operator.
Two-layer (rubber and vinyl matting)
These dual layer ESD mats have a dissipative surface resistance of 10;7–10;9 Ohms and a conductive bottom layer (10;2-10;6).
They also often carry a significantly higher tolerance for heat from soldering irons, and a marked higher resistance to hazardous chemicals.
So that’s our guide to the basics of ESD matting (and everything else, if you factor in the need for associated anti-static equipment!).
Need to make your business’ workspace safe against static? Check out our Electrostatic Discharge Protection page. Or if you’re not sure exactly what you need, contact us and we’ll talk you through your options.