DesignSpark Electrical Logolinkedin
Menu Search
Ask a Question

Tips for Avoiding ESD in Your Manufacturing Plant

While ESD, or electrostatic discharge, may not seem dangerous in theory, it can be exceptionally so, especially for microelectronics and industrial machinery. It happens to be one of the few frequent events that can damage almost any computer or related hardware components. To make matters worse, discharge events can occur without anyone knowing or feeling anything.

Similar to what happens when you rub your feet on a carpet or soft surface and then touch metal objects — like a doorknob — ESD is a static discharge that moves from one conductive surface to another. Many refer to it as the “invisible menace” not just because of how often it occurs, but also how easy it is to miss.

To prevent a discharge, a ground can eliminate static buildup. The ground source may come in the form of a wrist strap, grounding mat or surface or even work environment segment. For example, some workers may be able to tap on a grounded section of their workbench.

Also, a wide variety of ESD-related tools can further prevent discharge problems. Tools include everything from an antistatic cover or bag to a type of antistatic spray that mitigates discharge potential for a component or electronic.

Avoiding ESD on the manufacturing floor, however, is a little more complicated. Typically, industrial environments involve higher-voltage situations that still exist today, despite many efficiency improvements for industry-related technologies. Industry experts have estimated the average electronics product losses due to ESD to be anywhere between 8 and 33%. In monetary damage, estimates run into the billions of dollars annually.

Electrostatic Discharge Protection on the Manufacturing Floor

The first step to electrostatic discharge protection is to identify and understand where it occurs, affected materials and how a charge flows. When positive and electric charges have the opportunity to equalize, that’s when a discharge happens, and they will effectively flow through any path available to make it happen.

Also, certain materials like styrofoam, plastics, electronic components and devices, and even the human body are more capable of creating and facilitating an electric discharge.

The fundamentals of electrostatic discharge protection begin with circuit design processes. The right design will ensure ESD damage doesn’t affect electrical components, boards and the like. Ineffective design is one of the common reasons for PCB failure. However, even the best designs will not stop ESD from happening outright. Only the right prevention measures within a manufacturing plant can do that.

Manufacturers must put process guidelines and procedures in place to eliminate the possibility of ESD, including through the use of special protective equipment. Even something as simple as antistatic gloves can be the difference between hundreds of damaged goods or none at all.

In some cases, failures caused as a result of ESD may be minor, which means they will not necessarily manifest until later in the product’s lifecycle. With some consumer electronics, this issue is merely costly, but when you’re talking about more sensitive electronics — such as medical implants — the consequences can be severe.

Preventing static buildup is the best way to protect products and electronics. Here are some tips for doing so.

1. Implement an ESD Control Program

The absolute best way to prevent ESD is to create a protected area. Electrostatic discharge prevention measures keep everything within the space — including objects, workbenches, equipment, people and extraneous items — at the same electrical potential. Cover all surfaces in groundable materials, which have an electrical resistance rating of fewer than 109 ohms. A similar technique bonds any loose items to a ground. A bonded surface such as an antistatic mat covers the floor, so any people in the area remain bonded too.

The ESD control program incorporates not just this kind of setup, but also a process for reviewing and maintaining the environment as a regular operation. The program should explicitly call for personnel to review an area before beginning their workday, which ensures the adequate maintenance of all conditions. It also includes a policy to assess and replace equipment, tools, and other items that should remain bonded if and when there is a problem.

2. Proper ESD Garments

It’s a common misconception that wearing an ESD coat or suit automatically protects the nearby equipment and electronics. That is not true at all. The garments must have an electrical bond just like anything else. Otherwise, they’re nothing more than another type of conductor.

Proper ESD wear also calls for the use of bonded footwear, or grounded wrist straps to reduce the potential for discharge. Besides, specific garments lose their ESD properties over time, which means they require regular replacement.

3. Always Check ESD Control Compliance

Many organizations invest a lot of time and money into the installation of ESD control products and systems. When installed and maintained properly, they are incredibly useful, but they require regular assessment. Failure to review the systems or check them after installation means that they could be working out of specification.

Implement a compliance verification plan to check the equipment and systems periodically, but also to ensure that the proper testing equipment is available and is also in working order. It’s easy to see at this point that adequate maintenance is necessary for all tools, components, and systems and should be an integral part of any manufacturing operation.

4. Damaged or Ineffective Shielding Gear

ESD shielding bags and films can help store, transport or protect sensitive goods. Under the right conditions, they create a secure environment or a Faraday cage. But the shielding is vulnerable to tears, cuts, scratches and more. Companies can also use shielding gear when packaging or shipping goods to customers.

Companies that want to save money may reuse the same shielding materials or bags, which inadvertently introduces any related goods to a growing risk. The damaged shielding no longer functions properly as a protective film or cover. The same is true of everything from antistatic gloves to bags and even sprays.

Put a proper system in place to review, monitor and replace damaged shielding and similar components as soon as possible. Never reuse bags and films, no matter how well-kept they appear to be. Using equipment or supplies out of expiration is also not a smart strategy for the same reason.

5. Proper Cleaning Techniques for ESD Matting

Another common issue is workers use standard household cleaning products on ESD matting, garments, and other bonded goods. Most cleaners include silicone, which spreads out in a thin layer upon the cleaned surface, giving it a fresh and shiny look. The problem is that the thin silicone layer creates insulation, reducing the grounding performance of the material and increasing the potential for static discharge.

There are cleaners designed specifically for use with ESD mats, which is what companies should use on the manufacturing floor. Do not rely on regular household cleaners in ESD-protected areas. Periodic cleaning is necessary especially to remove dust, dirt, and debris, but correct handling means using the right chemicals and cleaners.

6. Adequate Employee Training

No matter how skilled or experienced employees are, everyone should have to participate in regular training and awareness courses. Most operations only require new hires to complete such training, and that’s it. It should be a continuous program, however, as repeated training exercises help refresh those actively working in the field.

Recurring training programs will also allow experienced workers to stay abreast of any new methods, technologies, and systems that get introduced as operations evolve.

Protect Your Manufacturing Facility and Goods From ESD Damage

By following these tips, and implementing the proper ESD prevention solutions, you can mitigate static discharge almost completely within your facility. That will go a long way to improving the quality of goods and products your plant produces, but it will also protect everything contained within, including industrial equipment, electronics, and machinery.

Megan R. Nichols is a freelance technical writer and blogger. She writes regularly for sites like American Machinist, DZone, and Electronic Design. Megan also enjoys writing easy to understand science and technology articles on her blog, Schooled By Science, to encourage others to take an interest in STEM. When she isn't writing, Megan enjoys watching movies and hiking with friends.

9 Dec 2019, 15:39