ESD workstation flaws are more common than you might think. Static risks arrive at your ESD workstation from a variety of sources, including incoming shipments, tools, parts, test equipment, chairs and even the clothes and shoes your workforce wears. Most of the major flaws at your workstation can be avoided by identifying three general concerns:
- Insulator situations which allow charges to build.
- Hidden charge sources which bring static to your ESD-sensitive area.
- Electrical overstress which might not cause immediate failures, but lowers the quality of products leaving your facility.
ESD awareness takes more than common sense; it's a science that may not be obvious to the casual observer. Stay alert when your processes change and you'll recognize many of the subtle ways that static charges can build.
3 Common ESD Workstation Problems
All three of these general workplace problems are avoidable.
- Insulators - Workplace routines take care of many common ESD problems, but even subtle changes can introduce surprise elements. For example, many wire racks hold their shelves in place with plastic wedges which insulate each shelf from the rack.
- Hidden charges - If workers wear special ESD smocks to cover their clothing they should never roll up their sleeves. Exposed clothing that is not ESD-safe puts your equipment at risk of static discharge, even if the body is properly grounded. Everyone is a walking static generator that builds hidden charges from simple actions, such as shuffling the feet, moving a chair, and other casual motions that occur without proper grounding.
- Electrical Overstress (EOS) - Careful ESD protection affects the ongoing quality of products, as well as their performance and longevity. The importance of addressing EOS is becoming more important as the size of electronic circuits is reduced to produce more complex components.
Subtle damage from inadequate ESD workstation practices can degrade performance and limit the lifetime of delicate electronic parts. This can have a negative impact on your company's reputation and long-term success.
ESD Workstation Risks
Addressing these mistakes will help improve the daily results and audit scores of your work environment.
- Furniture - If you're borrowing chairs and stools from non-ESD safe areas, you're introducing a major risk. Plastic surfaces on furniture can experience a lot of movement which, in turn, generates significant static charges. Special covers can solve this problem temporarily, but in the long-term scope of safety, ESD-proof furniture is an important part of your workspace.
- Multiple Grounds - Everything in the workspace should return to a single ground. This negates the existence of electrical potential. An example would be items grounded to a water pipe versus those grounded to an electrical outlet. You need to make sure there's no reason for charges to jump from one item to another, especially through the sensitive items being worked on.
- Wrist Strap Testing - Testing isn't just putting a mark on a checklist. To ensure that your wrist strap is doing its job, permanently set testers to the correct setting. This will help your workforce avoid false readings. Make sure there are adequate test stations near work areas so testing is convenient. Pocket testers should be used in areas where testing stations aren’t available. It’s important to ensure that coiled cord connections aren’t stretched when they’re plugged in. It’s a good idea to move around during testing, rather than holding still to see if the reading varies due to an intermittent connection.
- Assumptions. It can be frustrating, but you need to be suspicious of anything unapproved by your ESD safety team. This is especially true with materials coming between products and a grounded work surface. A piece of plastic used as a makeshift cutting board, for example, is a risky insulator. Non-ESD waste bins can hold a charge with the potential to transfer and cause damage. Shipping materials are potential ESD workstation hazards.
Anything that contains plastic or vinyl, from binders to dust covers, should be approved by your safety team before being used in the ESD workstation. Audit failures are often traced back to a simple, incorrect assumption.
Establishing an ESD Defense
It takes investments of time and money to mitigate the ESD risks that sneak onto your factory floor or into your laboratory. Following safety procedures will make a huge difference. Look for habits that contaminate an ESD-safe space and address them before it’s too late.
Advances in technology can result in ever greater ESD costs. However, companies that focus on ESD safety experience yield improvements as high as 10% with excellent ROI. Industry-wide, ESD is a problem that costs businesses billions of dollars. Focusing on increased ESD workstation safety will pay off in the long run.