ohm – Ground Zero Electrostatics Blog

15 Jun

Conductive, Dissipative, or Anti-Static Flooring?

You’re hard at work at your latest assignment. Your boss wants you to put together a complete plan for creating a large-scale electrostatic protection area (EPA) for a client who will be assembling various sensitive electronics and they want to avoid any risk of losing their investment due to electrostatic discharge (ESD).

You’ve selected the grounding cables, the workstations, the custom cut matting, containers and furniture, all designed to minimize or eliminate the slightest chance of ESD damage. But a curious thing happens when you research the proper flooring.

A simple Internet search for ESD flooring yields numerous options, more than you expect and you start to notice they all fall under 3 categories. In an instant, you’re faced with a decision, just like the game show, “Let’s Make a Deal.”

Suddenly, Monty Hall (or Wayne Brady, the current host!) is staring at you, asking do you want to choose door number one, number two, or number three: conductive, dissipative, or anti-static? The clock is ticking… How do you decide?

Door #1

For starters, let’s eliminate one of your options. Much like the ‘ZONKS’ of the game show, ‘anti-static’ is a worthless term in your ESD vocabulary. By strict definition, anti-static refers to a material that resists generating a charge. At one time it did designate a level of resistance, but was so overused and misunderstood, the term was removed from the ANSI/ESD standards.

So likewise, eliminate the term ‘anti-static’ from your discussion.

Deciding between the other two doors requires a closer look at the specific needs of the area for which the flooring is intended.

We’ve talked in another article about Ohms (Ω) and how they are the unit of measurement for resistance to electrical current.

Door #2

Because of the size and scope of most areas where it is necessary, the most common form of ESD flooring is referred to as ‘Static Conductive.’ Conductive flooring is at the low end of the electrical resistance scale.

Conductive carpeting may even be laced with carbon lines or metallic yarn fibers to encourage the flow of electricity. Because of the low electrical resistance, electrons flow easily across and through the surface, and can be grounded safely and quickly. This carpeting or vinyl tile is laid down with a conductive adhesive and grounded through the use of conductive tape or copper strips that run to a common ground.

This type of flooring is also generally a little more cost-effective than a dissipative solution.

Door #3

On the higher end of the resistance scale falls ‘Static Dissipative’ flooring. The higher resistance of these materials keeps the electrical charge more under control as it slowly flows over the surface and into a ground. Dissipative flooring is much more common in shared office environments where everyday shoes are more common, as opposed to a location where every element, from furniture to footwear, is controlled.

In our example above, the client will be assembling sensitive electronics like circuit boards and such in a large-scale environment. In this instance, a vinyl tile, or a poured epoxy flooring with conductive properties would most likely be the best option.

In an office setting where a company has their own IT department that fixes and assembles computers within the same facility, a dissipative, static resilient tiled floor would be a better fit.

But the fact is, these are very simplified examples of the myriad of variables that you can encounter when selecting the proper ESD controlled flooring. Your best option is to talk to an expert.

We’d love to be the experts you can count on for your full service, seamless ESD solutions. For more information or advice on your specific ESD flooring needs – or any other ESD questions, contact us today.

18 May

Conductive vs. Dissipative Materials

In the mid-1820’s, Georg Ohm, a self-taught mathematician and physicist, began doing experiments in the newly discovered field of electromagnetism. Hoping to advance his stalled career, he used the work of Hans Christian Ørsted as a jumping off point, discovering an inverse mathematical relationship between current and resistance.

Georg Simon Ohm

Unfortunately, in an effort to make his theories more understandable to non-mathematicians, he managed to alienate the scientific community and his groundbreaking work went unrecognized for almost 15 years.

Today, he’s remembered by the law that bears his name and its legacy, the standardized unit by which we measure electrical resistance – the Ohm (Ω).

Electrical Resistance: The Water in Pipe Analogy

To put it simply, what Ohm had discovered, but failed to adequately communicate, is that electricity acts like water in a pipe. In this analogy, resistance tells us how wide or narrow the “pipe” transmitting the electricity is.

When two items touch each other, they create an electrostatic charge – one item is positively charged, and one negatively charged. When the items are separated, it creates a triboelectric effect – a buildup of potential energy which can result in an electrostatic discharge (ESD).

In our quest to prevent ESD, which can be damaging and potentially catastrophic to sensitive electronics and circuitry, there are several approaches that vary, depending on the situation.

To illustrate those, we go back to Ohm’s electrical “pipe.”

At the narrowest end of the pipe, we have insulative materials – wood, carpeting, plexiglass. Insulative materials prevent or severely limit the flow of electrons across their surface.

While it may seem that this is the highest and best protection, the opposite is actually true. Because insulative materials are self-contained, they do not ground – meaning the potential energy continues to build up without going anywhere, until it comes into contact with another object, at which point, the new item is bombarded with the electrostatic discharge.

At the widest end of the pipe, we find the conductive materials – copper, steel, water. Conductive materials offer almost no resistance to electrostatic discharge. The electrical charge moves quickly through the materials – too quickly, which can lead to significant problems, as well as safety hazards.

In between these two extremes are the two materials most often used for ESD storage containers, matting and flooring: static conductive and static dissipative.

Towards the wider end of our metaphorical pipe, we find static conductive materials. Because of the low electrical resistance, electrons flow easily across the surface, and can be grounded safely. Typically, static conductive materials are most often used for ESD flooring.

Towards the narrower end of the pipe we find static dissipative materials. The higher resistance of these materials keeps the electrical charge more under control as it slowly flows over the surface and into a ground. Static dissipative materials are much more commonly used for ESD prevention and can be found in table top mats, ESD shoes and some flooring.

For storage containers – boxes, bins & totes – both conductive and dissipative materials can be used, depending on individual needs. Just keep in mind that dissipative materials have a higher resistance than conductive materials.

For more information, or an even more technical discussion of the properties of ESD materials, contact us today. We would love to be your full service, seamless ESD solution provider.

11 May

10 Common Terms in ESD & What They Mean

In 1865, Lewis Carrol published Alice’s Adventures in Wonderland, at the time, a thinly veiled political commentary wrapped in a fictional form.

Who knew that 150 years later, the book would have spawned several movies, pop cultural references, and a Grace Slick song.

But the most enduring artifact of the novel in today’s world – possibly reinforced by its own self-reference in the Matrix films, is the term “Rabbit hole.” In Alice’s universe, it meant falling into a world of confusion. Today it means losing track of time as you plumb the depths of a topic.

In our effort to be a provider of full service ESD solutions, we give you… The ESD rabbit hole – 10 Common Terms in ESD and What They Mean…

10 Common ESD Terms

The obvious place to start is with the term itself: ESD

ESD stands for ElectroStatic Discharge, a specific type of Electrical Overstress (EOS), defined as the sudden flow of electricity between two electrically charged objects caused by an electrical short, insulation failure, or simple contact. This is most often observed as static electric shock.

Electrical Overstress (EOS) is the exposure of an item to a current or voltage beyond what it can handle. When we’re talking ESD, it’s not just a static shock – because of the nature of sensitive electronics, even just a tiny bit of energy generated by lifting your hand or sliding across a desk can be dangerous enough to damage a component while you’re working, which is shy we recommend common grounding.

Common Grounding is a grounded device where two or more conductors are bonded, or a system for connecting two or more grounding conductors to the same electrical potential. Think of it as a lightning rod for your workstation.

Triboelectric Charging is the generation of electrostatic charges when two materials make contact, or often are rubbed together, then separated. This is what most people call static cling. The polarity and strength of the charges produced differ according to the properties of the materials.

Surface Resistance is measured in Ohms, and tells you how easily an electrical charge can travel across a type of surface. It might be helpful to think in terms of a water pipe analogy. The higher the resistance, the narrower the pipe. In the ESD world, a surface is either conductive or dissipative.

Conductive – A surface is conductive when it has a low resistance, anywhere from no resistance at all, such as water or copper, to mid-level resistance. This would be the wider of the two water pipes.

Static Dissipative – A surface is dissipative when it has a higher resistance, anywhere from the top end of the conductive to so much resistance that only a tiny trickle of “water” comes through the pipe.

Degradation is static electricity damage that weakens an electronic device, while giving the appearance of operating within normal parameters. However, once degraded, a device may fail catastrophically at a later point or just not last as long as it should.

Catastrophic failure is static electricity damage to a device that causes it to cease to function. The device must be replaced.

Ionization is the process by which a neutral atom or molecule acquires either a positive or a negative charge.

To Neutralize is to eliminate an electrostatic field by recombining positive and negative charges, either by conducting the charge to ground or by introducing an equal opposite charge. The charges cancel each other out, leaving a zero charge on the item.

We would love to be your full service, seamless ESD solution provider. For a deeper explanation of any of these terms and how they affect your workplace, contact us today for more information.