Monthly Archives: August 2015

Static electricity, the phenomenon responsible for electrostatic discharge, is responsible for everything from simple, often harmless effects like a child’s hair standing up on a playground slide to much more dangerous incidents like fires at the gas pump and even the Hindenburg disaster.

We’ve all experienced the shock of touching a doorknob—or perhaps even another person—after walking across carpeted floors, but perhaps few of us really understand what “static electricity” really is… and fewer understand what causes it.

What is Static Electricity?

“Static” electricity is latent electrification of an object. Unlike “current” electricity, which flows through substances, a “static” buildup involves acquiring an electrical charge which remains until it is discharged.

In the simplest of terms, “static electricity” refers to a positive or negative electrical charge. An object, or indeed a person, can build up excess electrons (a “negative” charge) or can lose electrons (a “positive” charge).

More specifically, the surface of an object is where this electrical charge resides.

How Does Static Electricity Build Up?

The most common means of a person or an object acquiring an electrical charge is a process known as “triboelectric” charging. Triboelectric is derived from the Greek, tribo- (‘rub’) and ēlektron (‘amber’), which is one of the earlier substances known to have been responsible for the “triboelectric” effect, and is thus the origin of the terms, “electron” and “electricity.”

As the Greek origins of the word imply, triboelectricity is often the result of rubbing, or friction. However, friction is not required to produce the charging effect.

In reality, simple contact followed by separation can produce an electrical charge in many substances. Amber and wool, for example, will produce triboelectricity when brought into contact with one another and then separated.

Other examples of substances known to produce the triboelectric effect:

• glass and silk
• rubber and fur
• hair/skin and certain plastics & vinyls

All that is needed for the build-up of an electrical charge is contact, followed by separation. In this simple example, a woman starts fueling her vehicle, then gets inside. Presumably, all it took was contact between her shoes and the vehicle’s carpet, or perhaps her skin and the fabric on the seat, to produce a buildup of static electricity:

What Causes Electrostatic Discharge?

As you can see in the video above, the woman has picked up a static charge by contact with the interior of her vehicle.

A “discharge” occurs when the object (or person, in this case) which has built up a negative or positive surface charge comes into close proximity or contact with another object that has a different charge. In the video above, the woman comes into contact with metal (either in the pump or the vehicle itself) and a small spark (or electrical arc) is produced.

Given her close proximity to the fumes of the gasoline, the results are predictable.

A similar discharge occurs when you walk across a carpeted floor in shoes in rubber-soled shoes and then touch a doorknob or other metal.

The real problem for businesses comes in when that electrostatic discharge occurs near sensitive equipment. This type of discharge can produce immediate, catastrophic failure, or even minor damage that doesn’t produce failure for a long time to come.

In future blog posts, we’ll talk about various aspects of electrostatic discharge, and why prevention is so important.

In the mean time, remember that electrostatic discharge is the reason that you always want to place your gas can on the ground before filling it up. Your truck bed or carpeted trunk is a recipe for disaster!

Electrostatic discharge, the rapid (and often unforeseen) flow of electricity that results when two electrically charged objects come into contact with one another, is an incredibly common phenomenon that wreaks havoc to the tune of billions of dollars each year in costs.

Whether your business produces ESD-sensitive equipment, or uses ESD-sensitive equipment in your operation, chances are you are dealing with significant costs associated with ESD—whether you’re aware of it or not.

Most electronic equipment has some degree or another of sensitivity to electrostatic discharge, and of course it’s hard to imagine many situations in which we do not come into contact with electronics on a daily basis. In fact, we’re often not aware of the most basic scenarios in which we generate an electrostatic discharge in everyday life, including plugging a charged USB cable into a laptop or even touching a cellphone when we carry a charge.

The manufacturers of the most ubiquitous devices have been working for decades to reduce vulnerability to ESD, and yet the costs associated with it continue to skyrocket.

The Costs of ESD

Sometimes the costs associated with Electrostatic Discharge (ESD) are obvious. For manufacturers who produce integrated circuits (ICs) or any products that contain them, product failures are perhaps the most significant source of ESD costs.

Cisco estimates that the costs of ESD damage are:

• 1x the cost of assembly and labor if found during assembly,
• 10x the cost of assembly and labor if found during testing, and
• 100x the cost of assembly and labor if found at the customer site.

The problem is that ESD damage can be hard to detect. Even with more than $5 billion in costs associated with ESD each year, it is likely that the majority of true costs are not properly attributed to ESD.

In the event of catastrophic or complete failure of a given device subsequent to a known ESD event, responsibility for the failure is easy to discover. The problem is that human beings cannot detect the familiar ESD “arc” until approximately 3000 volts. The threshold for damage to sensitive circuits can be as low as 100 volts, meaning that the vast majority of electrostatic discharge events may be going unnoticed.

Even more insidious, however, is the latent damage that can be caused by electrostatic discharge. Often the damage produced by ESD isn’t discoverable until much later, meaning that the true cause of a product or system failure may not be known, and therefore cannot be accounted for in any meaningful way.

Killing ESD at the Source

Often, companies invest in reducing the effects of ESD rather than trying to stop the causes of it. Even so, return on investment can be measurably very high.

To truly gain a significant ROI, however, the investment must be made in preventing ESD by eliminating the causes of it, not just mitigating its effects.

In manufacturing or handling sensitive electronic equipment, creating an Electrostatic Discharge Protected Area is a great starting point, with all manner of ESD protection, including:

• ESD flooring
• Grounding devices like wrist straps
• Grounded static dissipative work surfaces
• ESD clothing and shoes
• ESD packaging
• Signage

Whether you’re designing manufacturing facilities, operating a production line, or interacting with electronic circuits at any level, we’re here to assist you with any and all of the questions you deal with. As experts in the prevention and elimination of ESD for more than 15 years, we have the expertise, know-how, and depth of products to help you solve any of your ESD challenges.

In the coming weeks and months, we’re excited to be able to begin to share our expertise with you via this blog, and we look forward to interacting with you here!